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www.arquivosonline.com.br Sociedade Brasileira de Cardiologia • ISSN-0066-782X • Volume 107, Nº 3, September 2016

EditorialThe Year in Cardiology 2015: Prevention

Original ArticleSyntax Score and Major Adverse Cardiac Events in Patients with

Suspected Coronary Artery Disease: Results from a Cohort Study

in a University-Affiliated Hospital in Southern Brazil

Effects of Air Pollutant Exposure on Acute Myocardial Infarction,

According to Gender

Jabuticaba-Induced Endothelium-Independent Vasodilating Effect

on Isolated Arteries

Proportional Mortality due to Heart Failure and Ischemic Heart

Diseases in the Brazilian Regions from 2004 to 2011

Fondaparinux versus Enoxaparin – Which is the Best

Anticoagulant for Acute Coronary Syndrome? – Brazilian

Registry Data

Complications after Surgical Procedures in Patients with Cardiac

Implantable Electronic Devices: Results of a Prospective Registry

Prevalence and Phenotypic Expression of Mutations in the MYH7,

MYBPC3 and TNNT2 Genes in Families with Hypertrophic

Cardiomyopathy in the South of Brazil: A Cross-Sectional Study

Relationship Between Neck Circumference and Epicardial Fat Thickness

in a Healthy Male Population

Review ArticleCardiac Regeneration using Growth Factors: Advances and Challenges

Clinicoradiological SessionCase 5/2016 – Native Coarctation of the Aortic Arch, Relieved By

Percutaneous Treatment in an Adult

Case ReportComplicated Sinus of Valsalva Aneurysm Initially Diagnosed as Atrial

Myxoma

ImageST Segment Elevation Myocardial Infarction in Coronary Arteries with

Massive Ectasy

Letter to the EditorHeart Rate Recovery and Selective Serotonin Reuptake Inhibitors

Figure 2 – Cardiac Magnetic Resonance showing the presence of sinus of Valsalva aneurysm filled with thrombus. RV: right ventricle; LV: left ventricle. Page 280

Arquivos Brasileiros de Cardiologia - Volume 107, Nº 3, Seteptember 2016

REVISTA DA SOCIEDADE BRASILEIRA DE CARDIOLOGIA - Publicada desde 1948

Sumário - Contents

Editorial

The Year in Cardiology 2015: PreventionM. John Chapman, Stefan Blankenberg, Ulf Landmesser.....................................................................................................................................................................page 195

Original Articles

Chronic Coronary Artery Disease

Syntax Score and Major Adverse Cardiac Events in Patients with Suspected Coronary Artery Disease: Results from a Cohort Study in a University-Affiliated Hospital in Southern BrazilFelipe C. Fuchs, Jorge P. Ribeiro (in memorian), Flávio D. Fuchs, Marco V. Wainstein, Luis C. Bergoli, Rodrigo V. Wainstein, Vanessa Zen, Alessandra C. Kerkhoff, Leila B. Moreira, Sandra C. Fuchs.....................................................................................................................................................................page 207

Epidemiology

Effects of Air Pollutant Exposure on Acute Myocardial Infarction, According to GenderTássia Soldi Tuan,Taís Siqueira Venâncio,Luiz Fernando Costa Nascimento.....................................................................................................................................................................page 216

Pharmacology / Toxicology

Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated ArteriesDaniela Medeiros Lobo de Andrade, Leonardo Luis Borges, Ieda Maria Sapateiro Torres, Edemilson Cardoso da Conceição, Matheus Lavorenti Rocha.....................................................................................................................................................................page 223

Heart Failure

Proportional Mortality due to Heart Failure and Ischemic Heart Diseases in the Brazilian Regions from 2004 to 2011Eduardo Nagib Gaui, Carlos Henrique Klein, Glaucia Maria Moraes de Oliveira.....................................................................................................................................................................page 230

Ischemia/Myocardial Infarction

Fondaparinux versus Enoxaparin – Which is the Best Anticoagulant for Acute Coronary Syndrome? – Brazilian Registry DataAlexandre de Matos Soeiro,Pedro Gabriel Melo de Barros e Silva,Eduardo Alberto de Castro Roque,Aline Siqueira Bossa,Maria Cristina César,Sheila Aparecida Simões,Mariana Yumi Okada,Tatiana de Carvalho Andreucci Torres Leal,Fátima Cristina Monteiro Pedroti,Múcio Tavares de Oliveira Jr......................................................................................................................................................................page 239


Pacemaker

Complications after Surgical Procedures in Patients with Cardiac Implantable Electronic Devices: Results of a Prospective RegistryKatia Regina da Silva, Caio Marcos de Moraes Albertini, Elizabeth Sartori Crevelari, Eduardo Infante Januzzi de Carvalho, Alfredo Inácio Fiorelli, Martino Martinelli Filho, Roberto Costa.....................................................................................................................................................................page 245

Cardiomyopathies

Prevalence and Phenotypic Expression of Mutations in the MYH7, MYBPC3 and TNNT2 Genes in Families with Hypertrophic Cardiomyopathy in the South of Brazil: A Cross-Sectional StudyBeatriz Piva e Mattos, Fernando Luís Scolari, Marco Antonio Rodrigues Torres, Laura Simon, Valéria Centeno de Freitas, Roberto Giugliani, Úrsula Matte.....................................................................................................................................................................page 257

Relationship Between Neck Circumference and Epicardial Fat Thickness in a Healthy Male PopulationUğur Küçük, Hilal Olgun Küçük, Ferhat Cüce, Sevket Balta.....................................................................................................................................................................page 266

Review Article

Cardiac Regeneration using Growth Factors: Advances and Challenges

Juliana de Souza Rebouças, Nereide Stela Santos-Magalhães, Fabio Rocha Formiga.....................................................................................................................................................................page 271

Clinicoradiological Session

Case 5/2016 – Native Coarctation of the Aortic Arch, Relieved By Percutaneous Treatment in an AdultEdmar Atik and Raul Arrieta.....................................................................................................................................................................page 276

Case Report

Complicated Sinus of Valsalva Aneurysm Initially Diagnosed as Atrial Myxoma

Rafael Plens Teixeira, Pedro Felipe Gomes Nicz, Felipe Lourenço Fernandes, Renner Augusto Raposo Pereira, Roney Orismar Sampaio, Flavio Tarasoutchi.....................................................................................................................................................................page 279


Image

ST Segment Elevation Myocardial Infarction in Coronary Arteries with Massive EctasyAna Rita G. Francisco, José Duarte, Miguel Nobre Menezes, José Marques da Costa, Pedro Canas da Silva, Fausto J. Pinto.....................................................................................................................................................................page 282

Letter to the Editor

Heart Rate Recovery and Selective Serotonin Reuptake Inhibitors

Levent Cerit.....................................................................................................................................................................page 285

Editorial BoardBrazilAguinaldo Figueiredo de Freitas Junior (GO)Alfredo José Mansur (SP)Aloir Queiroz de Araújo Sobrinho (ES)Amanda G. M. R. Sousa (SP)Ana Clara Tude Rodrigues (SP)André Labrunie (PR)Andrei Sposito (SP)Angelo A. V. de Paola (SP)Antonio Augusto Barbosa Lopes (SP)Antonio Carlos C. Carvalho (SP)Antonio Carlos Palandri Chagas (SP)Antonio Carlos Pereira Barretto (SP)Antonio Cláudio L. Nobrega (RJ)Antonio de Padua Mansur (SP)Ari Timerman (SP)Armenio Costa Guimarães (BA)Ayrton Pires Brandão (RJ)Beatriz Matsubara (SP)Brivaldo Markman Filho (PE)Bruno Caramelli (SP)Carisi A. Polanczyk (RS)Carlos Eduardo Rochitte (SP)Carlos Eduardo Suaide Silva (SP)Carlos Vicente Serrano Júnior (SP)Celso Amodeo (SP)Charles Mady (SP)Claudio Gil Soares de Araujo (RJ)Cláudio Tinoco Mesquita (RJ)Cleonice Carvalho C. Mota (MG)Clerio Francisco de Azevedo Filho (RJ)Dalton Bertolim Précoma (PR)Dário C. Sobral Filho (PE)Décio Mion Junior (SP)Denilson Campos de Albuquerque (RJ)Djair Brindeiro Filho (PE)Domingo M. Braile (SP)Edmar Atik (SP)Emilio Hideyuki Moriguchi (RS)

Enio Buffolo (SP)Eulogio E. Martinez Filho (SP)Evandro Tinoco Mesquita (RJ)Expedito E. Ribeiro da Silva (SP)Fábio Vilas-Boas (BA)Fernando Bacal (SP)Flávio D. Fuchs (RS)Francisco Antonio Helfenstein Fonseca (SP)Gilson Soares Feitosa (BA)Glaucia Maria M. de Oliveira (RJ)Hans Fernando R. Dohmann (RJ)Humberto Villacorta Junior (RJ)Ines Lessa (BA)Iran Castro (RS)Jarbas Jakson Dinkhuysen (SP)João Pimenta (SP)Jorge Ilha Guimarães (RS)José Antonio Franchini Ramires (SP)José Augusto Soares Barreto Filho (SE)José Carlos Nicolau (SP)José Lázaro de Andrade (SP)José Péricles Esteves (BA)Leonardo A. M. Zornoff (SP)Leopoldo Soares Piegas (SP)Lucia Campos Pellanda (RS)Luís Eduardo Rohde (RS)Luís Cláudio Lemos Correia (BA)Luiz A. Machado César (SP)Luiz Alberto Piva e Mattos (SP)Marcia Melo Barbosa (MG)Marcus Vinícius Bolívar Malachias (MG)Maria da Consolação V. Moreira (MG)Mario S. S. de Azeredo Coutinho (SC)Maurício I. Scanavacca (SP)Max Grinberg (SP)Michel Batlouni (SP)Murilo Foppa (RS)Nadine O. Clausell (RS)Orlando Campos Filho (SP)Otávio Rizzi Coelho (SP)

Otoni Moreira Gomes (MG)Paulo Andrade Lotufo (SP)Paulo Cesar B. V. Jardim (GO)Paulo J. F. Tucci (SP)Paulo R. A. Caramori (RS)Paulo Roberto B. Évora (SP)Paulo Roberto S. Brofman (PR)Pedro A. Lemos (SP)Protásio Lemos da Luz (SP)Reinaldo B. Bestetti (SP)Renato A. K. Kalil (RS)Ricardo Stein (RS)Salvador Rassi (GO)Sandra da Silva Mattos (PE)Sandra Fuchs (RS)Sergio Timerman (SP)Silvio Henrique Barberato (PR)Tales de Carvalho (SC)Vera D. Aiello (SP)Walter José Gomes (SP)Weimar K. S. B. de Souza (GO)William Azem Chalela (SP)Wilson Mathias Junior (SP)

ExteriorAdelino F. Leite-Moreira (Portugal)Alan Maisel (Estados Unidos)Aldo P. Maggioni (Itália)Cândida Fonseca (Portugal)Fausto Pinto (Portugal)Hugo Grancelli (Argentina)James de Lemos (Estados Unidos)João A. Lima (Estados Unidos)John G. F. Cleland (Inglaterra)Maria Pilar Tornos (Espanha)Pedro Brugada (Bélgica)Peter A. McCullough (Estados Unidos)Peter Libby (Estados Unidos)Piero Anversa (Itália)

Scientific DirectorRaul Dias dos Santos Filho

Chief EditorLuiz Felipe P. Moreira

Associated Editors

Clinical CardiologyJosé Augusto Barreto-Filho

Surgical CardiologyPaulo Roberto B. Evora

InterventionistCardiologyPedro A. Lemos

Pediatric/Congenital CardiologyAntonio Augusto Lopes

Arrhythmias/PacemakerMauricio Scanavacca

Non-InvasiveDiagnostic MethodsCarlos E. Rochitte

Basic orExperimental ResearchLeonardo A. M. Zornoff

A JOURNAL OF SOCIEDADE BRASILEIRA DE CARDIOLOGIA - Published since 1948

Epidemiology/StatisticsLucia Campos Pellanda

Arterial HypertensionPaulo Cesar B. V. Jardim

Ergometrics, Exerciseand Cardiac RehabilitationRicardo Stein

First Editor (1948-1953)† Jairo Ramos

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Chief Editor of the Brazilian Archives of CardiologyLuiz Felipe P. Moreira

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SBC Newsletter EditorCarlos Eduardo Suaide Silva

Presidents of State and Regional Brazilian Societies of CardiologySBC/AL – Pedro Ferreira de Albuquerque

SBC/AM – Marcelo Mouco Fernandes

SBC/BA – Nivaldo Menezes Filgueiras Filho

SBC/CE – Sandro Salgueiro Rodrigues

SBC/CO – Danilo Oliveira de Arruda

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SBC/RO (SOCERON) – João Roberto Gemelli

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Sociedade Brasileira de Cardiologia

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SBC/DA – André Arpad Faludi

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Editorial

The Year in Cardiology 2015: PreventionM. John Chapman1,2, Stefan Blankenberg3, Ulf Landmesser4,5

National Institute for Health and Medical Research (INSERM), Pesquisa em Dislipidemia e Aterosclerose, Pitié-Salpêtrière University Hospital1, Paris FR-75651, France; University of Pierre and Marie Curie2, Paris, França; Clinic for Cardiology, University Heart Center Hamburg, German Center for Cardiovascular Research (DZHK)3, Hamburgo, Alemanha; Departamento de Cardiologia, Charité Universitätsmedizin Berlin (CBF)4, Berlim, Alemanha; German Center for Cardiovascular Research (DZHK), Berlin Institute of Health (BIH)5, Berlim, Alemanha

First published by Oxford University Press on behalf of the European Society of Cardiology in European Heart Journal [Chapman MJ, Blankenberg S, Landmesser U. The year in cardiology 2015: prevention. Eur Heart J. 2016 Feb 7;37(6):510-9]

Mailing Address: M. John Chapman •National Institute for Health and Medical Research (INSERM), Dyslipidemia and Atherosclerosis Research, Pitié-Salpetrière University Hospital, Paris FR-75651, FranceE-mail: [email protected]

KeywordsCardiovascular Diseases / prevention & control; Epidemiology;

Coronary Diseases / therapy; Morbidity; Mortality.

DOI: 10.1093/eurheartj/ehv721

PreambleImproved prevention of cardiovascular disease (CVD) is

of critical importance, as coronary heart disease (CHD) still represents the most common cause of death worldwide, engendering inestimable socioeconomic cost. The year 2015 has witnessed dramatic progress in CVD prevention on several fronts. Notably, this includes (i) event reduction in high-risk patients in general practice following introduction of a comprehensive strategy to attenuate modifiable risk factors, including lifestyle and dietary habits; (ii) the study of hybrid imaging to detect subclinical atherosclerosis, with potential improvement in risk prediction/management; (iii) the clinical demonstration, that culprit plaque rupture was observed in only 50–77% of patients with acute coronary syndromes; (iv) the emergence of ‘omics’ technologies to identify new causal biofactors; (v) the validation in clinical trials of the efficacy of monoclonalantibodies targeted to proprotein convertase subtilisin/kexin type 9 (PCSK9) in markedly reducing levels of low-density lipoprotein cholesterol (LDL-C) across a spectrum of patients at high risk ofpremature CVD, with preliminary findings strongly suggestiveof reduction in cardiovascular events; (vi) significant reductionof cardiovascular and all-cause mortality in diabetic patients inthe EMPA-REG OUTCOME trial with the anti-hyperglycaemicagent, empagliflozin, a selective sodium-glucose co-transporter-2 (SGLAT-2) inhibitor; (vii) new pharmacotherapeutic strategies for superior control of hypertension emanating from the PATHWAY-2 and PATHWAY-3 clinical trials involving spironoloactoneadd-on therapy in resistant hypertension, and amiloride plushydrochlorothiazide in hypertensive patients requiring a diuretic, respectively; and finally (viii) a reduced mortality associated with a lower blood pressure target of 120 mmHg in patients at highcardiovascular risk in the SPRINT trial. Considered together,such progress augurs well for the future control of dyslipidaemia, hyperglycaemia, and hypertension, and with it, progressivereduction in atherosclerotic vascular disease and associatedcardiovascular events in high-risk patients.

IntroductionThe prevention of CVDs represents an enormous challenge

to health professionals on a global scale. Indeed, on the basis of the 2015 World Health Organization database for the European region, and calculating age-standardized mortality rates with the new European Standard population, CVD remains the most common cause of death among Europeans, accounting for 40% in males and 49% in females, and equating to > 4 million deaths per year.1 While mortality from CHD and stroke have decreased overall across Europe over the past decade, CHD continues to represent the single most common cause of death.1 Importantly, morbidity data reveal that population-based rates of hospitalization for both CVD and stroke have increased; considered together with ever increasing rates of cardiovascular interventions, greater use of medications, and expanding needs for rehabilitation for disabilities, these overwhelming socioeconomic costs present a major burden to healthcare systems across Europe.1

How can we address this insurmountable challenge? Clearly lifestyle and diet represent our first line of action as currently recommended in recent guidelines,2,3 and early identification and management of modifiable risk factors is paramount. Indeed, Avanzini et al.4 have recently demonstrated that application of a comprehensive personalized preventive strategy in > 12 000 high-risk subjects in general practice, but with suboptimal baseline risk factor control, led to gradual and significant improvement in global cardiovascular risk profile over a 5-year period. Thus, improvement in risk factor profile in the first year (including physical inactivity, hypertension, hypercholesterolaemia, diabetes, and an unhealthy diet) was independently and significantly associated with lower rates of cardiovascular events in subsequent years. These findings are entirely consistent with new observations from the EPIC-Norfolk prospective population study, in which even small improvement in modifiable risk factors led to substantial reduction in cardiovascular events.5 These important findings indicate not only that an integrated approach to modifiable risk factor control is feasible, but equally that it is achievable in general practice. Finally, imaging technologies for detection of subclinical atherosclerosis may be invaluable in adding incremental value to strategies for diagnosis, risk stratification, and early initiation of prevention (see below).

The year 2015 is - and continues to be - a vintage one for seminal progress in our knowledge of the pathophysiology underlying acute coronary syndromes (ACSs), and of the epidemiology, diagnosis, and prognosis of CVD, thereby reflecting concerted efforts in our quest to prevent the global

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Chapman et. alThe year in cardiology 2015: prevention

Arq Bras Cardiol. 2016; 107(3):195-206

scourge of atherosclerotic vascular disease and its thrombotic complications. Such advances have been paralleled by the successful and rapid development of highly efficacious, innovative therapeutics to markedly lower circulating levels of LDL-C. Indeed, in the landmark INTERHEART study of risk factors for the first myocardial infarction across 52 countries worldwide, atherogenic cholesterol transported as LDL predominated, accounting for the majority of population-attributable risk.6 In this context, it is especially relevant that recent genetic findings, involving Mendelian randomization strategies which integrate lifelong and therefore cumulative risk exposure, have consolidated the evidence base for a causal role of LDL in the pathophysiology of atherosclerosis and CVD7–9 (Table 1). Moreover, the IMPROVE-IT trial10 has now demonstrated that a mechanism of LDL lowering distinct from that of statins translates into clinical benefit. Ezetimibe-mediated inhibition of intestinal cholesterol absorption yielded incremental lowering of LDL-C on a background of statin treatment in this trial (involving 18 144 patients hospitalized for an ACS over 7 years) and translated into moderate improvement in cardiovascular outcomes, i.e. a 7.2% lower rate of major vascular events. Baseline levels of LDL-C were low (1.8 mmol/L or 70 mg/dL), with a 24% further reduction when ezetimibe was added to simvastatin; that cardiovascular benefit is proportional to the degree of LDL-C reduction is of critical relevance in this context.11 Cardiovascular mortality was not modified, a finding which may result from several factors, and particularly the need for post-trial, long-term follow-up data on clinical benefit. Indeed, it is increasingly evident that such follow-up reveals legacy benefits of LDL lowering beyond the active intervention period in randomized, placebo-controlled statin trials, typically featuring decrease in cardiovascular death rates.12 Clearly then, a new paradigm is appearing in which LDL lowering therapies may alter the pathophysiological course of atherosclerotic vascular disease and its thrombotic complications, potentially by inducing lesion stabilization, or lesion regression, or both.

In this condensed distillate of advances in prevention of CVD over the past year, three key areas stand out. First, the evolution from emphasis on the ruptured, vulnerable coronary plaque to coronary plaque erosion in the context of ACS, with immediate relevance to approaches searching for ‘vulnerable’ plaques.13 Second, the appearance of advanced molecular methodologies for identification of biomarkers with potential for high predictive value.14 Third, the advanced development, based on the molecular genetics of familial traits for cholesterol dysmetabolism associated with premature atherosclerosis, of monoclonal antibodies targeted to PCSK9 for marked reduction in LDL-C levels.15 Importantly, progress in all three areas holds great promise to positively impact the care pathway for patients at high risk of CVD.

Plaque imaging and cardiovascular risk prediction

A recent hybrid imaging study to evaluate the systemic extent of atherosclerotic disease in the carotid, abdominal aortic, iliofemoral, and coronary arteries in a middle-aged population (the PESA Study, Progression of Early Subclinical Atherosclerosis) revealed subclinical atherosclerosis in 63% of participants (71% men, 48% women), who ranged from low

to high risk.16 With a similar approach, the BioImage Study (A Clinical Study of Burden of Atherosclerotic Disease in an At-Risk Population) evaluated the predictive value of carotid plaque burden (as examined by 3D ultrasound) and coronary artery calcification for cardiovascular risk assessment in a population of ∼6000 asymptomatic adults who underwent multimodality vascular imaging of both coronary and carotid arteries. Both imaging methods suggested that higher detected plaque burden was associated with adverse cardiovascular events; furthermore, both imaging methods improved cardiovascular risk prediction to a similar degree.17

Novel insights into coronary plaque pathobiology and mechanisms leading to progression towards acute coronary syndromes

Over recent years, coronary atherosclerotic plaque rupture and subsequent thrombus formation have been widely considered as the mechanism causing ACS. Subsequently, imaging studies have aimed to reveal the ‘vulnerable plaque’. High-resolution intracoronary imaging studies using optical coherence tomography (OCT) have now revealed that a significant proportion of ACS events are caused by coronary plaque erosion (on an intact fibrous cap) and subsequent intracoronary thrombus formation, in addition to those ‘classically’ resulting from coronary plaque rupture of vulnerable thin-cap fibro-atheroma rich in lipid.14 Indeed, Libby and Pasterkamp13 have highlighted this consideration in an editorial entitled ‘The requiem of the vulnerable plaque’, in which they discuss different plaque pathobiologies leading to ACS. Moreover, Niccoli et al.18 reported that ACS caused by coronary plaque erosion may have a better prognosis as compared with those due to coronary plaque rupture, as such events appear to result from late thrombi suggestive of less intense thrombotic stimuli, thereby allowing time for thrombus dissolution caused by spontaneous fibrinolysis. Finally, a recent meta-analysis of OCT studies suggested that the mean prevalence of culprit plaque rupture and thin-cap fibro-atheroma was almost 50% across different clinical subsets of patients; importantly, such events were most prominent in ST-elevation myocardial infarction (70–77%).19

Innovative methodologies for novel biomarker identification to assess cardiovascular risk

Although current risk models allow for increasingly precise risk equations in the general population, predicting life-threatening cardiovascular events at the level of the individual remains a challenge. More precise risk stratification, ideally based on causal factors, and personalization both of risk factor assessment and management are increasingly needed. A number of strategies have been employed to search for novel biomarkers of CVD. Unbiased technologies, including genomics, proteomics, and metabolomics, all utilize a ‘big data’ approach for novel biomarker discovery, but to date these technologies have failed to deliver on their initial promise, yielding no new clinically useful biomarkers in cardiac care. A genetic risk score has been analysed recently in clinical cohorts and data from randomized clinical statin trials and may identify individuals at increased risk for both incident and recurrent CHD events. People with the highest burden of this genetic risk derived the largest relative and absolute clinical benefit from statin therapy.20

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Arq Bras Cardiol. 2016; 107(3):195-206

Table 1 – Evidence that LDL is causal in the pathophysiology of atherosclerotic vascular disease and cardiovascular events

• Epidemiology of risk factors for myocardial infarction, INTERHEART

• Familial hypercholesterolaemia

• RCTs with statins and ezetimibe (intestinal cholesterol absorption inhibition)

• Molecular genetics

– Mendelian randomization studies

– PCSK9 loss-of-function mutations and variants

– PCSK9 gain-of-function mutations

• Arterial lipoprotein retention and direct implication of LDL in plaque lipid accumulation

• Statin-mediated reduction in circulating LDL-C levels with concomitant decrease in plaque lipid and increase in extracellular matrix content, favouring plaque stabilization

• Plaque regression (reduction in atheroma volume) by statins

RCTs: randomized controlled trials; LDL: low-density lipoprotein; LDL-C: LDL cholesterol.

An alternative strategy is to focus on known proteins reflecting mediating pathways to ensure a higher probability of association with CVD, an approach that can now be implemented on a massive scale using new multiplex immunoassay techniques that allow conservation of sample volume. This approach yielded promising results as recently tested in individuals with dysglycaemia.21 Further, non-coding RNAs including microRNAs are considered a potential biomarker, which might support diagnosis and prognosis in different cardiovascular conditions.22 Irrespective of big data approaches, single plasma biomarker assessment might be attractive to improve risk prediction models. Sensitive techniques to assess low concentrations of troponin I might open avenues to improve risk prediction in the general population by use of a cardiac-specific biomarker.22,23 Indeed, in the Bypass Angioplasty Revascularisation Investigation in Type 2 Diabetes trial, cardiac troponin T concentration measured with a high sensitivity assay was an independent predictor of death from cardiovascular causes, myocardial infarction, or stroke in patients who had both type 2 diabetes and stable ischaemic heart disease.24

Nevertheless, development of new strategies to identify causal biofactors is warranted in biological fluids, circulating cells, and tissues, and it is in this framework that emerging ‘omics’ technologies - metabolomics, lipidomics, proteomics, transcriptomics, and miRNAomics - augur well.14

Prevention of atherosclerotic vascular disease and cardiovascular events in dyslipidaemia

Statin intoleranceAs recommended in current European guidelines, statins

constitute first-line therapy in standard care for dyslipidaemic patients at high and very high cardiovascular risk in primary and secondary prevention.2,3 While the Cholesterol Treatment Trialists' meta-analyses of randomized controlled trials involving statins strongly substantiate their clinical efficacy,11 nonetheless, the profile of statin-associated adverse effects has been progressively clarified to reveal not only that statin-associated muscle symptoms (SAMSs) predominate in

observational studies, registries, and clinical practice (range of prevalence 7–29%), but also that they are the primary cause of statin discontinuation.25 To this end, the European Atherosclerosis Society (EAS) Consensus Panel recently issued a statement providing clinical guidance in the form of a flow-chart for management of patients with SAMS, and recognized the central role of attenuated mitochondrial energy production in skeletal muscle in its pathophysiology; it is noteworthy that inefficient first-pass statin uptake into the liver may critically underlie SAMS (Figure 1).25 It is equally relevant that SAMSs are a central feature of ‘statin intolerance’, which also includes adverse events at the level of the liver, kidney, peripheral tissues, and potentially the central nervous system, but whose frequency is markedly less than that of SAMS.25

Inter-individual variability in response to statin therapyInter-individual variability in response to statin

treatment has received little attention until late, when a pharmacogenetic meta-analysis of genome-wide association studies from randomized controlled trials and observational studies was reported, identifying the implication of two new genetic loci,SORT1/CELSR2/PSRC1 and SLCO1B1, in addition to those of APOE and LPA, in variation in LDL-C response.26 These findings take on added significance when it is considered that a substantial proportion of patients with incident CHD are hypo-responders to statin therapy, show minimal LDL-C reductions, and most importantly, greater atheroma progression as compared with responders.27 Under such circumstances, follow-up monitoring of LDL-C levels after initiation of statin becomes primordial to ensure goal attainment.

Familial hypercholesterolaemiaAlarmingly, the proportion of patients with familial

hypercholesterolaemia (FH) at LDL-C goal on statin treatment has been reported to be as low as 20% in the seminal Dutch experience; such patients are characterized by accelerated and premature atherosclerotic vascular disease and CHD.28,29 Several reasons may underlie this situation, some of which arise from the markedly elevated LDL-C levels frequently

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encountered at baseline in such patients. A maximally tolerated dose of an intensive statin is therefore the order of the day in FH, potentially in combination with ezetimibe, a synergistic association.7,28–30 Despite currently available therapies, however, FH in both its homozygous and heterozygous forms is widely underdiagnosed and undertreated, as emphasized by the EAS FH Consensus Panel.28,29 Indeed, the recent revelation from population genetic studies that FH is the most commonly inherited metabolic condition, with a population frequency approaching 1:200 persons, has warranted a call to action, with widespread creation of patient registries and FH patient advocacy groups.28,31 The under-diagnosis of FH is especially critical in children and adolescents, as emphasized recently by Wiegman et al.31 The evidence base in FH children treated with statins indicates not only that intervention with lipid lowering therapy may be safely initiated as early as 8 years of age, but also that when treated early in childhood, children born to FH families can anticipate normal life expectancy.31

The need for therapeutic innovation: PCSK9 inhibitionFrom the above, it is evident that innovative lipid lowering

therapies have been—and remain—urgently needed, always on a background of statin treatment whenever

possible, to fully translate the exceptional evidence base for reduction in cardiovascular events concomitant with LDL-C lowering into reality for many dyslipidaemic patients at high risk. Such patients include those with FH, those in secondary prevention, and those who are statin intolerant; additional patient populations may include individuals with diabetes, chronic kidney disease (CKD), and non-FH hypercholesterolaemia.15 It is in this context that the recent approval in the USA and Europe of two humanized monoclonal antibodies to PCSK9, alirocumab and evolocumab, is especially pertinent; the development of a third, bococizumab, which is partially humanized, is ongoing;32 all are well tolerated with a satisfactory safety profile.15,33-35 As exemplified by alirocumab, these antibodies act in vivo primarily by accelerating the fractional catabolic rate of LDL.36 An alternative approach to reduction of plasma PCSK9 concentrations involves direct inhibition of its hepatic production. A novel RNA interference drug, ALN-PCSsc (given as a subcutaneous formulation), has demonstrated the feasibility of this modality in phase 1 studies, resulting in a dose-dependent reduction in circulating PCSK9 levels of up to ≈80%, and a mean reduction in LDL-C of 40% for periods of 1 month or more, with favourable safety and tolerability.37

Figure 1 – Statin-associated muscle symptoms predominate as adverse effects among dyslipidaemic subjects who discontinue statin treatment. Available evidence suggests that the pathophysiological basis for statin-associated muscle symptoms arises from inefficient uptake of statins by the liver, i.e. ‘statin escape’, frequently as a result of genetically determined variation in the structure of organic anion transporter proteins, such as organic anion transporting polypeptide 1 encoded by the SLCO1B1 gene. Thus, variant forms of the protein may exhibit low binding affinity for the statin. Under these conditions, first-pass hepatic uptake of the statin is incomplete, leading to elevated levels of statin in the circulation with prolonged residence time. At high statin doses, accumulation of statins in plasma correlates with a poor low-density lipoprotein cholesterol lowering response and a distinct trend to increased frequency of statin-associated muscle symptoms and myopathy.25 As a consequence, peripheral tissues such as skeletal muscle are exposed to high statin concentrations with the potential for enhanced uptake; several mechanisms appear to contribute to statin-induced reduction in ATP production and mitochondrial function in muscle cells.25 High demand for energy production in muscle, as occurs in intense exercise, may potentiate statin-associated muscle symptoms.This Figure has been reprinted by permission of Oxford University Press on behalf of the European Society of Cardiology.

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Monoclonal antibodies to PCSK9The decade required for the development of monoclonal

antibodies to inhibit PCSK9 has been driven by novel genetic and mechanistic insights into the role of this protein in the regulation of the availability of surface LDL receptors primarily in the liver, its relation to the regulation of circulating LDL-C levels, and ultimately to cardiovascular morbi-mortality.38 Quasi-complete removal of plasma PCSK9 by antibody binding results in highly efficacious lowering of LDL-C in the range of 40–70% as a function of dose across dyslipidaemic patient phenotypes in monotherapy or on a statin background, with uptake of LDL–antibody complexes by cells of the reticuloendothelial system; the duration of antibody action is dose-dependent for both alirocumab and evolocumab, whose (single dose) pharmacokinetics and pharmacodynamics resemble each other.15,33,38 Moreover, anti-PCSK9-mediated LDL lowering is additive to that of statins and ezetimibe.15,33,38 Importantly, the efficacy of these antibodies is independent of the specific class of the mutation of the LDL receptor (receptor negative, defective, unclassified, or no mutation detected) in heterozygous FH;39 this effect attests to the fact that PCSK9 action in vivo typically leads to the premature degradation of a major proportion of LDL receptors, a pathway largely neutralized by PCSK9 antibody treatment.15

In the ‘Year in Cardiology 2014’, De Backer et al.40 comprehensively reviewed extensive data from the phase III randomized controlled trials with alirocumab and evolocumab; clinical trial updates for 2015 are currently available in recent reviews.15,38 Of late, the ODYSSEY FH I and FH II (heterozygous FH) trials included the option to increase the antibody dose to 150 mg every 2 weeks when LDL-C goal was not attained on the starting dose (75 mg every 2 weeks). In this way, some 59–68% of patients achieved an LDL-C goal of < 1.8 mmol/L (70 mg/dL).41 Discontinuation due to treatment-emergent adverse events occurred in 3.4% of antibody-treated patients vs. 6.1% on placebo, while injection site reactions were reported for 12.4% in FH I and 11.4% in FH II ( vs. 11.0 and 7.4%, respectively for placebo), thereby attesting to satisfactory tolerability. Importantly and overall, these findings are consistent with those reported in FH heterozygotes upon treatment with evolocumab in the RUTHERFORD-2 trial, albeit involving a distinct dosing regimen from that above for alirocumab;39 furthermore, additional novel trial data have recently been reported in FH homozygotes in the TAUSSIG and TESLA trials (comprehensively reviewed by Chapman et al.15).

Safety of PCSK9 inhibition: vitamin E, gonadal hormones, cognitive function, very low LDL-C, and anti-drug binding or neutralizing antibodies

As lipophilic vitamin transport and steroidogenesis are intimately linked to LDL-C metabolism, it was critical to provide safety data for the potential impact of these innovative therapeutics on vitamin E and steroid hormone levels.42 Thus, in the 52 week, double-blind randomized placebo-controlled DESCARTES study, evolocumab, on a background of statin, did not affect gonadal hormone levels up to 52 weeks of treatment, while changes in vitamin E paralleled those in lipoproteins; erythrocyte vitamin E levels were unchanged.42

Equally, adrenocorticotrophic hormone (ACTH) levels and the cortisol/ACTH ratio did not change, even when LDL-C levels were very low (< 0.88 mol/L or 15 mg/dL).

Given that long-term statin therapy is associated with new onset diabetes, particularly in individuals presenting with features of prediabetes and the metabolic syndrome,43 it is imperative to exclude potential effects of PCSK9 inhibition on glucose homeostasis. Recent findings in the OSLER trial over a period of 52 weeks, involving subjects with impaired fasting glucose, metabolic syndrome and type 2 diabetes, demonstrate convincingly that PCSK9 inhibition (as evolocumab) was without effect on fasting plasma glucose and glycated haemoglobin (HbA1c) levels.44 Recent data with alirocumab equally indicate the lack of any adverse signal on glycaemic control.45,46

Practitioners frequently express two lingering concerns with respect to marked lowering of circulating LDL-C concentrations: first, low LDL-C levels may raise a range of safety issues; and second, prompted by concerns of the US Food and Drug Administration, low LDL-C on statin treatment may lead to deterioration of cognitive function. Importantly, patients who achieved very low LDL-C levels on statins displayed lower risk for major cardiovascular events.47 Furthermore, recent data from the OSLER trial have documented the absence of any safety signal as a function of on-treatment LDL-C levels down to 0.65 mmol/L (25 mg/dL).38 Similarly, ODYSSEY LONG TERM showed no increase in the incidence of AEs in patients attaining very low LDL-C levels (< 0.65 mmol/L or 25 mg/dL).48 Moreover, no significant signal concerning cognitive function has been detected to date in either the ODYSSEY or PROFICIO clinical trials programme.34,35 In addition, new findings from a Mendelian randomization study do not support a causal link between low LDL-C (< 1.5 mmol/L) and dementia, Parkinson's disease, or epilepsy.49 Notwithstanding these findings, the EBBINGHAUS trial, a substudy of the FOURIER outcomes trial, will examine the effect of evolocumab-induced low LDL-C levels on cognitive function using objective assessments.50 Finally, composite findings to date in the ODYSSEY and PROFICIO clinical trials programmes have revealed a very low incidence of anti-drug binding or neutralizing antibodies, involving 0.1–7.3% (placebo-corrected) of patients; the presence of such antibodies is typically transient.34,45,41 Long-term follow-up data will be essential to evaluate this key question fully, as it may equally be relevant to instances when a contingency for patients to switch antibodies may arise.

A word of caution is in order when considering the nature of ‘very low LDL-C levels'. Typically, such levels are calculated on the basis of the Friedewald equation, and therefore include the cholesterol content of lipoprotein(a) [Lp(a)], thereby overestimating true LDL-C. In subjects with elevated Lp(a) levels and ‘very low LDL’, however, LDL may be effectively absent from plasma, and thus the readout potentially corresponds to Lp(a) cholesterol; the clinical implications of this concept are indeterminate.51

Under these conditions, ultracentrifugal isolation of LDL provides an accurate readout.

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Cardiovascular outcomes trialsIt is encouraging that exploratory analyses of ODYSSEY

LONG TERM (alirocumab, n = 2341) and OSLER (evolocumab, n = 4465) indicate diminution in cardiovascular outcomes of 50–55% over treatment periods of up to 78 weeks.44,48,52 Moreover, a recent meta-analysis of 24 trials of PCSK9 antibody therapy, involving > 10 000 patients, highlighted a 55% reduction in all-cause mortality (p < 0.015), with similar decrements in cardiovascular mortality and myocardial infarction.53 Together with the SPIRE clinical trial programme for bococizumab,54,55 the FOURIER (patients with a history of CVD and at high risk of recurrent events)56 and ODYSSEY OUTCOMES (patients recently hospitalized for ACS)57

trials involve > 70 000 high-risk dyslipidaemic patients (Figure 2). While the findings are fully anticipated to confirm the preliminary observations discussed above, they will be essential elements in the evaluation of the long-term efficacy, tolerability, and cost-effectiveness of PCSK9 inhibition. We should not forget, however, that the trajectory of CVD over time is not limited to a single cardiovascular event, and that lowering LDL-C exerts cumulative, long-term arterial benefit, modifying the pathophysiological trajectory of atherosclerotic vascular disease.12 Therefore, critical appraisal of these agents should integrate their cumulative, long-term health benefits both for the individual and potentially for healthcare systems. In this light, we summarize future perspectives for PCSK9 inhibition in Table 2.

Beyond the LDL-C target: triglyceride-rich lipoproteins and lipoprotein(a)

In addition to LDL-C, PCSK9 inhibition, by virtue of its marked enhancement of LDL receptor number, may impact components of the atherogenic lipid profile beyond LDL-C, including triglyceride-rich lipoproteins and remnants (TGRL); such action may equally modulate levels of both high-density lipoprotein (HDL) and apolipoprotein (apo)AI via intravascular remodelling mechanisms. As exemplified by early results from OSLER, atherogenic TGRL levels are significantly reduced when PCSK9 is inhibited, while those of HDL/apoAI may increase;4 similar findings have been made across the ODYSSEY phase III studies.34 Further information on these actions as a function of baseline lipid profile will be of special interest, as we cannot exclude the possibility that they may enhance clinical benefit gained from LDL-C reduction alone.

The lack of therapeutic effect of statins on a potent atherothrombogenic lipid risk factor, Lp(a) has been perplexing, especially as abundant evidence now supports the contention that it is a causal, genetically determined and independent risk factor for premature CVD.58,59 Moreover, Mendelian randomization studies have documented a key role for Lp(a) in calcific aortic valve disease, an observation supported by new mechanistic insights intimately linked to its content of oxidized phospholipids.60,61 The finding then that PCSK9 inhibition reduces circulating Lp(a) levels by up to 35%,62,63 and that this effect may reside at least partially in the supra-physiological availability of LDL receptors for its catabolism, represents a major mechanistic advance.64 The ongoing cardiovascular outcomes studies for PCSK9 inhibitors may reveal whether Lp(a) reduction contributes

to overall reduction in events. Ultimately, however, the answer to this question may require an outcomes trial involving antisense inhibition of hepatic apo(a) production in patients at high cardiovascular risk displaying elevated Lp(a) levels; such a scenario has entered the realm of possibility with the ongoing development of ISIS-APO(a) Rx, which can reduce Lp(a) concentrations by up to 80% dose-dependently.65

Unmet clinical needs in dyslipidaemia: the therapeutic horizonClinical needs in moderate hypertriglyceridaemia are

largely unmet to date, and are a central target on our therapeutic radar screen, especially the highly atherogenic mixed dyslipidaemia involving elevated levels of TGRL and subnormal HDL-C, a profile typical of insulin resistance.66,67 Molecular genetics has clearly identified the majority of such dyslipidaemic states as polygenic, upon which environmental influences are superimposed.66,68 Nonetheless, in the light of new genetic insights indicating that a loss-of-function mutation in apoCIII leads to concomitant fall in levels of TGRL and in cardiovascular risk, novel targeting of the apoCIII gene by antisense inhibition brings considerable optimism to this arena.69 Indeed, dose-dependent reductions attaining ≈80% in hypertriglyceridaemic patients (baseline triglycerides ∼4.0–22.6 mmol/L or 350–2000 mg/dL) were found using a weekly injection protocol in phase II studies.69 No safety concerns were identified.

Patients with CKD are at high cardiovascular risk;3 preliminary findings suggest that PCSK9 inhibition is as efficacious in LDL-C lowering in those with moderate CKD as in those with mild or without CKD, with no evidence of safety issues.70

Cardiovascular prevention in diabetesAfter numerous cardiovascular outcome studies over the

past years in patients with diabetes, suggesting no short- and medium-term risk reduction with anti-hyperglycaemic agents, the EMPA-REG OUTCOME trial reported a significant reduction of cardiovascular and all-cause mortality using a selective SGLAT-2 inhibitor, empagliflozin in patients with type 2 diabetes at high cardiovascular risk.71

These observations will have a significant impact on the future management of cardiovascular prevention in patients with type 2 diabetes.

Novel insights into better control of hypertensionThe PATHWAY-2 study has suggested that spironolactone

is a particularly effective add-on drug for the treatment of resistant hypertension.72 The results of the PATHWAY-3 study support the first-line use of amiloride plus hydrochlorothiazide in hypertensive patients who need treatment with a diuretic.73 The DENERHTN study examined 106 patients with well-defined resistant hypertension and suggested that renal denervation plus an standardized stepped-care antihypertensive treatment (SSAHT) decreased ambulatory blood pressure more than the same SSAHT alone at 6 months,74 raising hope that renal denervation may lower blood pressure in well-selected patients.

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Figure 2 – A schematic summary of the ongoing cardiovascular outcome trials for the three monoclonal antibodies to proprotein convertase subtilisin/kexin type 9, on a background of human LDL particles visualized by negative stain electron microscopy (copyright M.J.C.). The upper section of the figure shows a 2D image of the PCSK9 protein, while the lower section shows an image of an LDL particle bound to the biding domain of the LDL receptor. Overall, some 70 000 dyslipidaemic patients at high risk will be included in these multicentre, international trials. The primary endpoints in these trials, which are expected to report over the period of 2016–17 are as follows: FOURIER: cardiovascular death, myocardial infarction, hospitalization for unstable angina, stroke, or coronary revascularization, whichever occurs first;56 ODYSSEY OUTCOMES: coronary heart disease death, any non-fatal myocardial infarction, fatal and non-fatal ischaemic stroke, unstable angina requiring hospitalization;57 SPIRE 1 and SPIRE-2: major cardiovascular event, a composite endpoint that includes cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for unstable angina needing urgent revascularization.54,55 ACS: acute coronary syndrome; CV: cardiovascular; CVD: cardiovascular disease; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol.This Figure has been reprinted by permission of Oxford University Press on behalf of the European Society of Cardiology.

Importantly, the SPRINT study75 demonstrated that among patients at high risk for cardiovascular events but without diabetes, targeting a systolic blood pressure of < 120 mmHg, as compared with < 140 mmHg, resulted in lower rates of fatal and non-fatal major cardiovascular events and death from any cause, although significantly higher rates of some adverse events were observed in the intensive-treatment group. This trial was larger than the previous ACCORD study, where a trend for a lower rate of cardiovascular events was observed with more intensive blood pressure lowering.

Summary and conclusionThe year 2015 has seen dramatic progress in the control

of dyslipidaemia, hyperglycaemia, and hypertension. These risk factors exert their nocivity throughout the course of the atherogenic process. Dyslipidaemia may, however, be unique as a target to attenuate progression of

advanced plaques, and it is in this context that the marked efficacy of PCSK9 inhibition in lowering LDL-C to levels below the critical value of 1.8–2.1 mmol/L (70–80 mg/dL) required to stop progression in the majority of patients may present major therapeutic interest.76,77 Indeed, could rapid reduction of LDL-C to very low levels post cardiovascular event result in rapid lipid depletion and enhanced fibrous matrix content across diffuse plaques in the arterial tree, and with it, irreversible—or long-term—plaque stabilization with subsequent reduction in cardiovascular events? Could rapid attenuation of dyslipidaemia by PCSK9 inhibitors attenuate endothelial erosion on complex plaques, indirectly diminishing thrombotic complications? Such questions challenge cardiology, obliging us to determine the most efficacious pharmacotherapeutic strategies for CVD prevention. Finally, the first large cardiovascular outcome data of

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Table 2 – PCSK9 inhibition: future perspectives

Cardiovascular outcomes from phase III trials

Impact on atherosclerotic vascular disease (Glagov imaging trial)

Impact of triglyceride-rich lipoproteins, remnant and lipoprotein(a) lowering, and HDL/apolipoprotein AI raising, on progression of disease and reduction in cardiovascular events

Long-term, real-life, safety data from post-marketing surveillance, including the safety of very low levels of LDL-C, and potential frequency of anti-drug binding or neutralizing antibodies

Evaluation of efficacy and safety in children and adolescents with heterozygous familial hypercholesterolaemia at high risk (the HAUSER-RCT trial)

Evaluation of efficacy in other patient populations at high risk, to include post-menopausal females, chronic kidney disease, type 1 and type 2 diabetics, peripheral arterial disease and autoimmune diseases

Use of PCSK9 antibody therapy to amplify and prolong LDL apheresis-mediated LDL-C lowering in severely affected familial hypercholesterolaemia patients, with potential to reduce frequency of apheresis treatment sessions

Evaluation of long-term cost-effectiveness as a function of long-term patient follow-up in individual healthcare systems

HDL: high-density lipoprotein; LDL: low-density lipoprotein; LDL-C: LDL cholesterol.

SGLAT-2 inhibition will have a major impact on the future treatment of diabetes, and in hypertension, the PATHWAY and SPRINT studies have provided valuable insights into optimization of treatment.

Authors’ contributionsM.J.C., S.B., and U.L. acquired the data, drafted the

manuscript, and made critical revision of the manuscript for key intellectual content.

Acknowledgement:The authors are indebted to Jane Stock for assistance with

literature documentation.

Conflict of interestM.J.C. has received research funding from CSL, Kowa,

MSD, Pfizer and Randox Laboratories, and honoraria for participation in Speakers Bureaux and Advisory Boards of Amgen, AstraZeneca, Kowa, Merck, Pfizer, Sanofi-Regeneron, and Unilever. U.L. has received lecture/advisory board honoraria or research funding from Roche, Sanofi, Amgen, MSD, Pfizer, Servier, Menarini, Astra, St Jude, Orbus&Neich, and Terumo. S.B. reports no disclosures. S.B. has received

research funding from Abbott, Abbott Diagnostics, Bayer, Boehringer Ingelheim, SIEMENS and Thermo Fisher. He received honoraria for lectures from Abbott, Abbott Diagnostics, Astra Zeneca, Bayer, Boehringer Ingelheim, Medtronic, Pfizer, Roche, SIEMENS Diagnostics, SIEMENS, Thermo Fisher and as member of Advisory Boards and for consulting for Boehringer Ingelheim, Bayer, Novartis, Roche and Thermo Fisher.

Copyright

First published in European Heart Journal [Volume 37, Issue 6, 7 february 2016, DOI: 10.1093/eurheartj/ehv721] and reproduced with permission from Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. If you wish to reproduce, reuse or distribute this article in any way, please contact [email protected] to request permission.

Translation

Oxford University Press, and the European Society of Cardiology are not responsible or in any way liable for the accuracy of the translation. The Sociedade Brasileira de Cardiologia is solely responsible for the translation in this publication.

1. Townsend N, Nichols M, Scarborough P, Rayner M. Cardiovascular disease in Europe 2015: epidemiological update. Eur Heart J. 2015;36(40):2696-705.

2. Perk J, De Backer G, Gohlke H, Graham I, Reiner Z, Verschuren WM, et al; European Association for Cardiovascular Prevention & Rehabilitation (EACPR); ESC Committee for Practice Guidelines (CPG). European Guidelines on cardiovascular disease prevention in clinical practice (version 2012). The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease

Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Eur Heart J. 2012;33:1635-701. Erratum in: Eur Heart J. 2012;33(17):2126.

3. Reiner Z, Catapano AL, De Backer G, Graham I, Taskinen MR, Wiklund O, et al; ESC Committee for Practice Guidelines (CPG) 2008-2010 and 2010-2012 Committees. ESC/EAS guidelines for the management of dyslipidaemias: the Task Force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS). Eur Heart J. 2011;32(14):1769-818.

References

202

Editorial


Arq Bras Cardiol. 2016; 107(3):195-206

4. Avanzini F, Marzona I, Baviera M, Barlera S, Milani V, Caimi V, et al; Risk and Prevention Study Collaborative Group. Improving cardiovascular prevention in general practice: results of a comprehensive preventive strategy in subjects at high risk. Eur J Prev Cardiol. 2016;23(9):947-55.

5. Lachman S, Peters RJ, Lentjes MA, Mulligan AA, Luben RN, Wareham NJ, et al. Ideal cardiovascular health and risk of cardiovascular events in the EPIC-Norfolk prospective population study. Eur J Prev Cardiol. 2016;23(9):986-94.

6. Yusuf S, Hawken S, Ounpuu S, Dans T, Avezum A, Lanas F, et al; INTERHEART Study Investigators. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364(9438):937-52.

7. Catapano AL, Ference BA. IMPROVE-IT and genetics reaffirm the causal role of LDL in cardiovascular disease. Atherosclerosis. 2015;241(2):498-501.

8. Ference BA, Yoo W, Alesh I, Mahajan N, Mirowska KK, Mewada A, et al. Effect of long-term exposure to lower low-density lipoprotein cholesterol beginning early in life on the risk of coronary heart disease: a Mendelian randomization analysis. J Am Coll Cardiol. 2012;60(25):2631-9.

9. Ference BA, Majeed F, Penumetcha R, Flack JM, Brook RD. Effect of naturally random allocation to lower low-density lipoprotein cholesterol on the risk of coronary heart disease mediated by polymorphisms in NPC1L1, HMGCR, or both: a 2 × 2 factorial Mendelian randomization study. J Am Coll Cardiol. 2015;65(15):1552-61.

10. Cannon CP, Blazing MA, Giugliano RP, McCagg A, White JA, Theroux P, et al; IMPROVE-IT Investigators. Ezetimibe added to statin therapy after acute coronary syndromes. N Engl J Med. 2015;372(25):2387-97.

11. Baigent C, Blackwell L, Emberson J, Holland LE, Reith C, Bhala N, et al; Cholesterol Treatment Trialists’ (CTT) Collaboration. Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170,000 participants in 26 randomised trials. Lancet. 2010;376(9753):1670-81.

12. Packard CJ, Ford I. Long term follow-up of lipid-lowering trials. Curr Opin Lipidol. 2015;26(6):572-9.

13. Libby P, Pasterkamp G. Requiem for the ‘vulnerable plaque’. Eur Heart J. 2015;36(43):2984-7.

14. Hoefer IE, Steffens S, Ala-Korpela M, Bäck M, Badimon L, Bochaton-Piallat ML, et al; ESC Working Group Atherosclerosis and Vascular Biology. Novel methodologies for biomarker discovery in atherosclerosis. Eur Heart J. 2015;36(39):2635-42.

15. Chapman MJ, Stock JK, Ginsberg HN; PCSK9 Forum. PCSK9 inhibitors and cardiovascular disease: heralding a new therapeutic era. Curr Opin Lipidol. 2015;26(6):511-20.

16. Fernández-Friera L, Peñalvo JL, Fernández-Ortiz A, Ibañez B, Lopez-Melgar B, Laclaustra M, et al. Prevalence, vascular distribution, and multiterritorial extent of subclinical atherosclerosis in a middle-aged cohort: the PESA (Progression of Early Subclinical Atherosclerosis) study. Circulation. 2015;131(24):2104-13.

17. Baber U, Mehran R, Sartori S, Schoos MM, Sillesen H, Muntendam P, et al. Prevalence, impact, and predictive value of detecting subclinical coronary and carotid atherosclerosis in asymptomatic adults: the BioImage study. J Am Coll Cardiol. 2015;65(11):1065-74.

18. Niccoli G, Montone RA, Di Vito L, Gramegna M, Refaat H, Scalone G, et al. Plaque rupture and intact fibrous cap assessed by optical coherence tomography portend different outcomes in patients with acute coronary syndrome. Eur Heart J. 2015;36(22):1377-84.

19. Iannaccone M, Quadri G, Taha S, D’Ascenzo F, Montefusco A, Omede’ P, et al. Prevalence and predictors of culprit plaque rupture at OCT in patients with coronary artery disease: a meta-analysis. Eur Heart J Cardiovasc Imaging. 2015 Oct 27. [Epub ahead of print].

20. Mega JL, Stitziel NO, Smith JG, Chasman DI, Caulfield MJ, Devlin JJ, et al. Genetic risk, coronary heart disease events, and the clinical benefit of statin therapy: an analysis of primary and secondary prevention trials. Lancet. 2015;385(9984):2264-71.

21. Gerstein HC, Paré G, McQueen MJ, Haenel H, Lee SF, Pogue J, et al; Outcome Reduction With Initial Glargine Intervention Trial Investigators. Identifying novel biomarkers for cardiovascular events or death in people with dysglycemia. Circulation. 2015;132(24):2297-304.

22. Zeller T, Tunstall-Pedoe H, Saarela O, Ojeda F, Schnabel RB, Tuovinen T, et al; MORGAM Investigators. High population prevalence of cardiac troponin I measured by a high-sensitivity assay and cardiovascular risk estimation: the MORGAM Biomarker Project Scottish Cohort. Eur Heart J. 2014;35(5):271-81.

23. Everett BM, Zeller T, Glynn RJ, Ridker PM, Blankenberg S. High-sensitivity cardiac troponin I and B-type natriuretic peptide as predictors of vascular events in primary prevention: impact of statin therapy. Circulation. 2015;131(21):1851-60.

24. Everett BM, Brooks MM, Vlachos HE, Chaitman BR, Frye RL, Bhatt DL; BARI 2D Study Group. Troponin and cardiac events in stable ischemic heart disease and diabetes. N Engl J Med. 2015;373(7):610-20.

25. Stroes ES, Thompson PD, Corsini A, Vladutiu GD, Raal FJ, Ray KK, et al; European Atherosclerosis Society Consensus Panel. Statin-associated muscle symptoms: impact on statin therapy.-European Atherosclerosis Society Consensus Panel Statement on Assessment, Aetiology and Management. Eur Heart J. 2015;36(17):1012-22.

26. Postmus I, Trompet S, Deshmukh HA, Barnes MR, Li X, Warren HR, et al; Pharmacogenetic meta-analysis of genome-wide association studies of LDL cholesterol response to statins. Nat Commun. 2014;5:5068.

27. Kataoka Y, St John J, Wolski K, Uno K, Puri R, Tuzcu EM, et al. Atheroma progression in hyporesponders to statin therapy. Arterioscler Thromb Vasc Biol. 2015;35(4):990-5.

28. Nordestgaard BG, Chapman MJ, Humphries SE, Ginsberg HN, Masana L, Descamps OS, et al; European Atherosclerosis Society Consensus Panel. Familial hypercholesterolaemia is underdiagnosed and undertreated in the general population: guidance for clinicians to prevent coronary heart disease: consensus statement of the European Atherosclerosis Society. Eur Heart J. 2013;34(45):3478-90a.

29. Cuchel M, Bruckert E, Ginsberg HN, Raal FJ, Santos RD, Hegele RA, et al; European Atherosclerosis Society Consensus Panel on Familial Hypercholesterolaemia. Homozygous familial hypercholesterolaemia: new insights and guidance for clinicians to improve detection and clinical management. A position paper from the Consensus Panel on Familial Hypercholesterolaemia of the European Atherosclerosis Society. Eur Heart J. 2014:35(32):2146-57.

30. Fazio S. The role of PCSK9 in intestinal lipoprotein metabolism: synergism of statin and ezetimibe. Atheroscler Suppl. 2015;17:23-6.

31. Wiegman A, Gidding SS, Watts GF, Chapman MJ, Ginsberg HN, Cuchel M, et al; European Atherosclerosis Society Consensus Panel. Familial hypercholesterolaemia in children and adolescents: gaining decades of life by optimizing detection and treatment. Eur Heart J. 2015;36(36):2425-37.

32. Ballantyne CM, Neutel J, Cropp A, Duggan W, Wang EQ, Plowchalk D, et al. Results of bococizumab, a monoclonal antibody against proprotein convertase subtilisin/kexin type 9, from a randomized, placebo-controlled, dose-ranging study in statin-treated subjects with hypercholesterolemia. Am J Cardiol. 2015;115(9):1212-21.

33. Dadu RT, Ballantyne CM. Lipid lowering with PCSK9 inhibitors. Nat Rev Cardiol. 2014;11(10):563-75.

34. Food and Drug Administration. (FDA). Center for Drug Evaluation and Research. The Endocrinologic and Metabolic Drugs Advisory Committee Meeting , June 9, 2015. Briefing document BLA 125559. Praluent (alirocumab) injection. [internet]. [Cited in

203

Editorial


Arq Bras Cardiol. 2016; 107(3):195-206

2015 Nov 3]. Available from: http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/Drugs/Endocr ino log icandMetabol icDrugsAdvi soryCommit tee/UCM449867

35. Food and Drug Administration. (FDA). Center for Drug Evaluation and Research. The Endocrinologic and Metabolic Drugs Advisory Committee Meeting, June 10, 2015. Briefing document. Repatha (evolocumab) injection. [internet]. [Cited in 2015 Nov 3]. Available from: http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/Drugs/EndocrinologicandMetabolicDrugsAdvisoryCommittee/UCM450072.pdf

36. Reyes-Soffer G, Pavlyha M, Ngai C, Thomas T, Holleran S, Ramakrishnan S, et al. Effects of a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, alirocumab, on lipid and lipoprotein metabolism in healthy subjects. (abstract). Circulation. 2015;132:A18390.

37. Fitzgerald K, Kallend D, White S, Borodovsky A, Sutherland J, Bettencourt B, et al. A phase 1, randomized, placebo-controlled, single ascending and multiple dose study of subcutaneously administered ALN-PCSSC in subjects with elevated low density lipoprotein cholesterol. (abstract). Eur Heart J. 2015;36(Suppl):309.

38. Shimada YJ, Cannon CP. PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors: past, present, and the future. Eur Heart J. 2015;36(36):2415-24.

39. Raal FJ, Stein EA, Dufour R, Turner T, Civeira F, Burgess L, et al; RUTHERFORD-2 Investigators. PCSK9 inhibition with evolocumab (AMG 145) in heterozygous familial hypercholesterolaemia (RUTHERFORD-2): a randomised, double-blind, placebo-controlled trial. Lancet. 2015;385(9965):331-40.

40. De Backer G, Kastelein JJ, Landmesser U. The year in cardiology 2014: prevention. Eur Heart J. 2015;36(4):214-8.

41. Kastelein JJ, Ginsberg HN, Langslet G, Hovingh GK, Ceska R, Dufour R, et al. ODYSSEY FH I and FH II: 78 week results with alirocumab treatment in 735 patients with heterozygous familial hypercholesterolaemia. Eur Heart J. 2015;36(43):2996-3003.

42. Blom DJ, Djedjos CS, Monsalvo ML, Bridges I, Wasserman SM, Scott R, et al. Effects of evolocumab on vitamin E and steroid hormone levels: results from the 52-week, phase 3, double-blind, randomized, placebo-controlled DESCARTES study. Circ Res. 2015;117(8):731-41.

43. Cederberg H, Stančáková A, Yaluri N, Modi S, Kuusisto J, Laakso M. Increased risk of diabetes with statin treatment is associated with impaired insulin sensitivity and insulin secretion: a 6 year follow-up study of the METSIM cohort. Diabetologia 2015;58(5):1109-17.

44. Sabatine MS, Giugliano RP, Wiviott SD, Raal FJ, Blom DJ, Robinson J, et al; Open-Label Study of Long-Term Evaluation against LDL Cholesterol (OSLER) Investigators. Efficacy and safety of evolocumab in reducing lipids and cardiovascular events. N Engl J Med. 2015;372(16):1500-9.

45. Colhoun HM, Ginsberg HN, Robinson JG, Leiter LA, Müller-Wieland D, Henry RR, et al. Alirocumab effect on glycemic measures in patients without diabetes at baseline. (abstract). Circulation. 2015;132(Suppl 3):A16863.

46. Ginsberg HN, Farnier M, Robinson JG, Cannon CP, Sattar N, Baccara-Dinet MT, et al. Efficacy and safety of alirocumab: pooled analyses of 1048 individuals with diabetes mellitus from five placebo-controlled Phase 3 studies of at least 52 weeks duration. (abstract). Circulation. 2015;132Suppl 3):A17070.

47. Boekholdt SM, Hovingh GK, Mora S, Arsenault BJ, Amarenco P, Pedersen TR, et al. Very low levels of atherogenic lipoproteins and the risk for cardiovascular events: a meta-analysis of statin trials. J Am Coll Cardiol. 2014;64(5):485-94.

48. Robinson JG, Farnier M, Krempf M, Bergeron J, Luc G, Averna M, et al; ODYSSEY LONG TERM Investigators. Efficacy and safety of alirocumab in reducing lipids and cardiovascular events. N Engl J Med. 2015;372(16):1489-99.

49. Benn M, Nordestgaard BG, Frikke-Schmidt R, Tybjærg-Hansen A. Low PCSK9 and LDL cholesterol and risk of dementia, Parkinson’s disease, and epilepsy—a Mendelian randomization study. (abstract). Circulation. 2015;132(Suppl 3):A19109.

50. EBBINGHAUS: Evaluating PCSK9 Binding antiBody Influence oN coGnitive HeAlth in High cardiovascUlar Risk Subjects. ClinicalTrials.gov Identifier: NCT02207634. [Cited in 2016 Jan 10]. Available from: https://clinicaltrials.gov/ct2/show/NCT02207634

51. Yeang C, Witztum JL, Tsimikas S. ‘LDL-C’=LDL-C+Lp(a)-C: implications of achieved ultra-low LDL-C levels in the proprotein convertase subtilisin/kexin type 9 era of potent LDL-C lowering. Curr Opin Lipidol. 2015;26(3):169-78.

52. Koren MJ, Giugliano RP, Raal FJ, Sullivan D, Bolognese M, Langslet G, et al; OSLER Investigators. Efficacy and safety of longer-term administration of evolocumab (AMG 145) in patients with hypercholesterolemia: 52-week results from the Open-Label Study of Long-Term Evaluation Against LDL-C (OSLER) randomized trial. Circulation. 2014;129(2):234-43.

53. Navarese EP, Kolodziejczak M, Schulze V, Gurbel PA, Tantry U, Lin Y, et al. Effects of proprotein convertase subtilisin/kexin type 9 antibodies in adults with hypercholesterolemia: a systematic review and meta-analysis. Ann Intern Med. 2015;163(1):40-51.

54. SPIRE-1: The Evaluation of Bococizumab (PF-04950615;RN316) in Reducing the Occurrence of Major Cardiovascular Events in High Risk Subjects. ClinicalTrials.gov Identifier: NCT01975376. [internet]. [Cited in 2016 Feb 15]. Available from: https://clinicaltrials.gov/ct2/show/NCT01975376

55. SPIRE-2: The Evaluation of Bococizumab (PF-04950615; RN316) in Reducing the Occurrence of Major Cardiovascular Events in High Risk Subjects. ClinicalTrials.gov Identifier: NCT01975389. [internet]. [Cited in 2016 Feb 15]. Available from: https://clinicaltrials.gov/ct2/show/NCT01975389

56. FOURIER: Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk. ClinicalTrials.gov Identifier: NCT01764633. [internet]. [Cited in 2016 Feb 15]. Available from: https://clinicaltrials.gov/ct2/show/NCT01764633

57. ODYSSEY Outcomes: Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab SAR236553 (REGN727). ClinicalTrials.gov Identifier: NCT01663402. [internet]. [Cited in 2016 Feb 15]. Available from: https://clinicaltrials.gov/ct2/show/NCT01663402

58. Nordestgaard BG, Chapman MJ, Ray K, Borén J, Andreotti F, Watts GF, et al; European Atherosclerosis Society Consensus Panel. Lipoprotein(a) as a cardiovascular risk factor: current status. Eur Heart J. 2010;31(23):2844-53.

59. Tsimikas S, Hall JL. Lipoprotein(a) as a potential causal genetic risk factor of cardiovascular disease: a rationale for increased efforts to understand its pathophysiology and develop targeted therapies. J Am Coll Cardiol. 2012;60(8):716-21.

60. Capoulade R, Chan KL, Yeang C, Mathieu P, Bossé Y, Dumesnil JG, et al. Oxidized phospholipids, lipoprotein(a), and progression of calcific aortic valve stenosis. J Am Coll Cardiol. 2015;66(11):1236-46.

61. Bouchareb R, Mahmut A, Nsaibia MJ, Boulanger MC, Dahou A, Lépine JL, et al. Autotaxin derived from lipoprotein(a) and valve interstitial cells promotes inflammation and mineralization of the aortic valve. Circulation. 2015;132(8):677-90.

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62. Raal FJ, Giugliano RP, Sabatine MS, Koren MJ, Langslet G, Bays H, et al. Reduction in lipoprotein(a) with PCSK9 monoclonal antibody evolocumab (AMG 145): a pooled analysis of more than 1,300 patients in 4 phase II trials. J Am Coll Cardiol. 2014;63(13):1278-88.

63. Gaudet D, Kereiakes DJ, McKenney JM, Roth EM, Hanotin C, Gipe D, et al. Effect of alirocumab, a monoclonal proprotein convertase subtilisin/kexin 9 antibody, on lipoprotein(a) concentrations (a pooled analysis of 150 mg every two weeks dosing from phase 2 trials). Am J Cardiol. 2014;114(5):711-5.

64. Romagnuolo R, Scipione C, Boffa MB, Marcovina SM, Seidah NG, Koschinsky ML. Lipoprotein(a) catabolism is regulated by proprotein convertase subtilisin/kexin type 9 through the low density lipoprotein receptor. J Biol Chem 2015;290(18):11649-62.

65. Tsimikas S, Viney NJ, Hughes SG, Singleton W, Graham MJ, Baker BF, et al. Antisense therapy targeting apolipoprotein(a): a randomised, double-blind, placebo-controlled phase 1 study. Lancet. 2010;386(10002):1472-83.

66. Hegele RA, Ginsberg HN, Chapman MJ, Nordestgaard BG, Kuivenhoven JA, Averna M, et al; European Atherosclerosis Society Consensus Panel. The polygenic nature of hypertriglyceridaemia: implications for definition, diagnosis, and management. Lancet Diabetes Endocrinol. 2014;2(8):655-66.

67. Chapman MJ, Ginsberg HN, Amarenco P, Andreotti F, Borén J, Catapano AL, e t a l ; European Atherosc leros i s Society Consensus Panel. Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management. Eur Heart J. 2011;32(11):1345-61.

68. Rosenson RS, Davidson MH, Hirsh BJ, Kathiresan S, Gaudet D. Genetics and causality of triglyceride-rich lipoproteins in atherosclerotic cardiovascular disease. J Am Coll Cardiol. 2014;64(23):2525-40.

69. Gaudet D, Alexander VJ, Baker BF, Brisson D, Tremblay K, Singleton W, et al. Antisense inhibition of apolipoprotein C-III in patients with hypertriglyceridemia. N Engl J Med. 2015;373(5):438-47.

70. Toth PP, Cannon CP, Kastelein JJ, Colhoun HM, Koren A, Louie MJ, et al. Alirocumab LDL-C-lowering efficacy in patients with moderate CKD. (abstract). Circulation. 2015;132:A17086.

71. Zinman B, Wanner C, Lachin JM, Fitchett D, Bluhmki E, Hantel S, et al; EMPA-REG OUTCOME Investigators. Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. N Engl J Med. 2015;373(22):2117-28.

72. Williams B, MacDonald TM, Morant S, Webb DJ, Sever P, McInnes G, et al; British Hypertension Society’s PATHWAY Studies Group. Spironolactone versus placebo, bisoprolol, and doxazosin to determine the optimal treatment for drug-resistant hypertension (PATHWAY-2): a randomised, double-blind, crossover trial. Lancet. 2015;386(10008):2059-68.

73. Brown MJ, Williams B, Morant SV, Webb DJ, Caulfield MJ, Cruickshank JK, et al; British Hypertension Society’s Prevention and Treatment of Hypertension with Algorithm-based Therapy (PATHWAY) Studies Group. Effect of amiloride, or amiloride plus hydrochlorothiazide, versus hydrochlorothiazide on glucose tolerance and blood pressure (PATHWAY-3): a parallel-group, double-blind randomised phase 4 trial. Lancet Diabetes Endocrinol. 2016;4(2):136-47.

74. Azizi M, Sapoval M, Gosse P, Monge M, Bobrie G, Delsart P, et al; Renal Denervation for Hypertension (DENERHTN) Investigators. Optimum and stepped care standardised antihypertensive treatment with or without renal denervation for resistant hypertension (DENERHTN): a multicentre, open-label, randomised controlled trial. Lancet. 2015;385(9981):1957-65.

75. Wright JT Jr, Williamson JD, Whelton PK, Snyder JK, Sink KM, Rocco MV, et al; SPRINT Research Group. A randomized trial of intensive versus standard blood-pressure control. N Engl J Med. 2015;373(22):2103-16.

76. Nicholls SJ, Ballantyne CM, Barter PJ, Chapman MJ, Erbel RM, Libby P, et al. Effect of two intensive statin regimens on progression of coronary disease. N Engl J Med. 2011;365(22):2078-87.

77. Nissen SE, Nicholls SJ, Sipahi I, Libby P, Raichlen JS, Ballantyne CM, et al; ASTEROID Investigators. Effect of very high-intensity statin therapy on regression of coronary atherosclerosis: the ASTEROID trial. JAMA. 2006;295(13):1556-65.

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Original Article

Syntax Score and Major Adverse Cardiac Events in Patients with Suspected Coronary Artery Disease: Results from a Cohort Study in a University-Affiliated Hospital in Southern BrazilFelipe C. Fuchs, Jorge P. Ribeiro (in memorian), Flávio D. Fuchs, Marco V. Wainstein, Luis C. Bergoli, Rodrigo V. Wainstein, Vanessa Zen, Alessandra C. Kerkhoff, Leila B. Moreira, Sandra C. FuchsHospital de Clínicas de Porto Alegre - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS – Brazil

Mailing Address: Felipe Costa Fuchs •Serviço de Cardiologia, Hospital de Clínicas de Porto Alegre. Rua Ramiro Barcelos, 2350, Santa Cecília. Postal Code 90035-903, Porto Alegre, RS – BrazilE-mail: [email protected] received July 05, 2015; revised manuscript March 21, 2016; accepted April 01, 2016.

DOI: 10.5935/abc.20160111

Abstract

Background: The importance of coronary anatomy in predicting cardiovascular events is well known. The use of traditional anatomical scores in routine angiography, however, has not been incorporated to clinical practice. SYNTAX score (SXscore) is a scoring system that estimates the anatomical extent of coronary artery disease (CAD). Its ability to predict outcomes based on a baseline diagnostic angiography has not been tested to date.

Objective: To evaluate the performance of the SXscore in predicting major adverse cardiac events (MACE) in patients referred for diagnostic angiography.

Methods: Prospective cohort of 895 patients with suspected CAD referred for elective diagnostic coronary angiography from 2008 to 2011, at a university-affiliated hospital in Brazil. They had their SXscores calculated and were stratified in three categories: no significant CAD (n = 495), SXscoreLOW-INTERMEDIATE: < 23 (n = 346), and SXscoreHIGH: ≥ 23 (n = 54). Primary outcome was a composite of cardiac death, myocardial infarction, and late revascularization. Secondary endpoints were the components of MACE and death from any cause.

Results: On average, patients were followed up for 1.8 ± 1.4 years. The primary outcome occurred in 2.2%, 15.3%, and 20.4% in groups with no significant CAD, SXscoreLOW-INTERMEDIATE, and SXscoreHIGH, respectively (p < 0.001). All-cause death was significantly higher in the SXscoreHIGH compared with the ‘no significant CAD’ group, 16.7% and 3.8% (p < 0.001), respectively. After adjustment for confounding factors, all outcomes remained associated with the SXscore.

Conclusions: SXscore independently predicts MACE in patients submitted to diagnostic coronary angiography. Its routine use in this setting could identify patients with worse prognosis. Arq Bras Cardiol. 2016; 107(3):207-215

Keywords: Coronary Artery Disease / epidemiology; Probability; Cineangiography; Syntax Score; Cohort Studies.

IntroductionThe importance of coronary anatomy in predicting

cardiovascular events has been known for decades, when studies like CASS (Coronary Artery Study) registry were published.1 This large cohort study showed the ability of anatomical scores of coronary artery disease (CAD) to predict events, but their routine use was not incorporated to clinical practice.2 Nowadays, standard of care indicates functional, noninvasive, assessment of ischemia, such as stress-echocardiogram, nuclear imaging and magnetic resonance imaging, to evaluate patients with known or suspected CAD.3 Nonetheless, a significant number of

patients are eventually submitted to coronary angiography for diagnostic confirmation.3 Therefore, re-assessing the performance of anatomical scores to predict outcomes, in a context of newer clinical and interventional therapies, is potentially worthwhile. Currently, the SYNTAX (Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery) Score (SXscore), a more elaborate method to quantify anatomic lesions, is an available online tool that estimates the anatomical extent of CAD.4

The SXscore is a comprehensive angiographic scoring system based on coronary anatomy and lesion characteristics.4 It was initially developed to determine the extent of CAD and lesion complexity, which reflect the difficulties in performing myocardial revascularization, particularly percutaneous coronary interventions (PCI). In the SYNTAX trial, high SXscore values (above 33) identified patients in whom coronary artery bypass grafting (CABG) resulted in better outcomes than in patients submitted to percutaneous revascularization.5 Five-year follow-up of this trial identified patients with scores above 22 as more suitable for CABG.6

The SXscore was developed as a tool in the decision-making process and, later on, its usefulness was expanded as

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a predicting score of major adverse cardiac events (MACE) in patients submitted to PCI.7-14 Those studies included elective and urgent revascularization procedures. However, the majority of coronary angiographies are done for diagnostic purposes.15 The prognostic performance of the SXscore in that setting has not been reported to date, and is the aim of this investigation.

ObjectiveTo evaluate the performance of the SXscore in predicting

MACE in patients referred for diagnostic angiography.

Methods

Study design and populationThis cohort study enrolled patients with suspected CAD

referred for elective, diagnostic coronary angiography, from 2008 to 2011, at a reference tertiary university-affiliated hospital (Hospital de Clínicas de Porto Alegre), in Southern Brazil. The patients were referred by cardiologists from the public health system and private practices, and underwent cardiac catheterization due to suspected CAD with or without previous noninvasive testing for ischemia. Patients referred for angiography due to suspected CAD and associated valvular heart disease were also included. Men and women aged 40 years or over were eligible for the study, excluding those with previous coronary revascularization (surgical or percutaneous), class III or IV heart failure, chronic renal disease (previous medical diagnosis or serum creatinine greater than 1.5 mg/dL), history of cancer, or severe psychiatric illness. Patients admitted to the hospital for acute coronary syndromes were not included.

Enrollment and study proceduresThe study protocol was approved by the hospital’s Ethics

Committee, which is accredited by the Office for Human Research Protections as an Institutional Review Board, and informed, written consent was obtained. Interviews pertaining demographic information, lifestyle characteristics, and past medical history were done using a standardized questionnaire. After the angiographies, the patients’ attending physicians were responsible for assessing the need for revascularization and all medical treatment. The follow-up was conducted from 2008 to 2012.

SYNTAX score and angiographic analysisSXscores were calculated prospectively by scoring all

coronary lesions producing a ≥ 50% diameter stenosis in vessels ≥ 1.5 mm, using the algorithm that is available at the SYNTAX score website.16 Subsequently, they were categorized as: SXscoreHIGH (≥ 23); SXscoreLOW-INTERMEDIATE (< 23); and no significant CAD (reference category). Two interventional cardiologists (FCF, LCCB) independently performed the angiographic visual analysis for the assessment of the score. They were trained in calculating the SXscore using the website tutorial. Afterwards, they scored another 80 cases, which were extensively discussed with senior interventional cardiologists.

Inter- and intra-observer agreement for determination of the SXscore was evaluated in another group of 90 angiographies.

Study endpointsThe primary endpoint was MACE, defined as a time to first

event among cardiac death, myocardial infarction (MI) or late revascularization. Myocardial infarction and revascularization followed by death in the same hospitalization were adjudicated as cardiac deaths. Cardiac death was defined, additionally, as sudden death. Myocardial infarction was diagnosed by an increase or decrease of biomarkers, in the presence of symptoms, ECG abnormalities suggestive of ischemia.17 Some patients were treated for acute MI in other hospitals and the diagnosis was defined on the basis of the discharge diagnosis. Late revascularization was either PCI or CABG.

Percutaneous and surgical revascularizations based on diagnostic angiography findings, performed until three months after the angiography, were defined as index procedures and not considered outcomes. Interventions performed during follow-up, non-directly related to the diagnostic angiography, were defined as late revascularizations and included in the primary outcome. Secondary endpoints were cardiac death, cardiovascular death (fatal MI or stroke), MI, coronary revascularization, and overall mortality.

All deaths were confirmed through verbal autopsy,18 death certificate (obtained at the Government’s Health Department, which has all state death records), or hospital records. Myocardial infarction was established by hospitalization, with diagnosis informed by a physician. An independent Clinical Events Committee adjudicated all endpoints. Data collection regarding the outcomes underwent control of quality to verify reliability, and another investigator checked 5% of the verbal autopsies.

Sample size calculation and statistical analysisThe questionnaires were coded and entered into a database

using Epinfo 2004 software (version 3.3.2, Centers for Disease Control and Prevention, Atlanta, USA), with data entry quality control to verify amplitude and consistency. A sample size of 588 participants would be necessary to identify a hazard ratio (HR) of at least 2.4, with 80% power and 5% significance level (two-tailed), considering that 5% of unexposed and 12% of exposed to the highest score, a 1:1.5 ratio, respectively, would present a primary endpoint. Considering the lack of previous reports about the performance of SXscore to predict events in this context, sample size was increased to 906 participants to include enough patients with high scores (>23) to provide adequate statistical power. Epi Info 2004, Statcalc module, was used for sample size calculation.

Inter and intra-observer reliability was assessed by crosschecking 90 angiograms evaluated by two interventional cardiologists and reviewed by a third one. Agreement using Kappa coefficient was done, and interpreted according to Feiss et al.19 Substantial agreement was defined by a Kappa coefficient of 0.7, considering the proportion of patients with SXscore > 23, being 30% according to observer 1 and 20% by observer 2, with accuracy of 0.2. Intraclass correlation coefficients were also calculated.

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Figure 1 – Flowchart of patients. PCI: percutaneous coronary intervention; CABG: coronary artery bypass grafting; MI: myocardial infarction; CAD: coronary artery disease; CV: cardiovascular; MACE: major adverse cardiac events. * Valve replacement patients were excluded from the outcome analysis. Ŧ MACE as defined in methods section.

Inde

x pr

oced

ure

Clin

ical

end

poin

ts

Eligible patientsn = 928

n = 28 eligibility not con�rmedn = 5 refused to participate

Interview + Angiography n = 895

Physicians’ decision

No interventionn = 499

PCIn = 239

CABGn = 75

Valve replacement*n = 82

PCI n = 35CABG n = 19

MIn = 16

Death AD: Cn = 13

Death: CVn = 22

All-cause deathn = 36

MACEŦ

n = 73

Recommendations of the STARD20 were used to plan and report this study. Data are presented by mean ±SD, percentages and HR with 95% confidence intervals (CI). Receiver operating characteristic (ROC) curve was used to calculate C-statistic and the area under the curve. Kaplan-Meier survival curve for MACE was calculated for patients according to SXscores. Multivariate analysis of the predictive power of the SXscore was performed using Cox regression, which allowed the estimation of HR and 95% CI. Variables associated to the outcome in the bivariate analysis (P ≤ 0.2) were eligible as confounding factors. Considering that many variables are intermediates in the causation of MACE, they were individually evaluated to be included or not in the analysis. The same model was run having the number of diseased vessels (none, one and multivessel) as exposure variable. The analyses were carried out using the Statistical Package for Social Sciences (SPSS®, version 17, Chicago, IL, USA) software, and a p value <0.05 was regarded as statistically significant.

ResultsStudy flowchart is presented in Figure 1. Among 928 eligible

patients, 895 patients with SXscore were included in the cohort and were followed up on average for 1.8 ± 1.4 years. After angiography, 314 (35.1%) patients were submitted to

PCI or CABG, and 82 (9.2%) to valve replacement (index procedure). New interventions were done during the follow-up (late revascularizations) in 54 patients (35 percutaneous and 19 surgical). Myocardial infarction occurred in 16 patients, cardiac death in 13, cardiovascular death in 22, and all-cause death in 40 patients. MACE was established in 73 patients.

Spearman coefficient between the SXscores calculated by the two interventional cardiologists was 0.902 (p < 0.001), and the interobserver agreement between them was 0.94 (95% CI: 0.91–0.96). Kappa coefficient was 0.83 for the two interventional cardiologists. There were 495 patients with a score of 0 (55.4%) and 400 (44.6%) with positive scores, ranging from 1 to 43, with a mean of 12.6 (95% CI: 11.7–13.4). Patients with coronary lesions ≥ 50% diameter stenosis in vessels ≥1.5 mm were classified as SXscoreLOW-INTERMEDIATE (n = 345) or SXscoreHIGH (n = 54).

Baseline clinical and angiographic characteristics according to patient categories are presented in Table 1. The mean age of patients with SXscoreHIGH was higher than that of patients with SXscoreLOW-INTERMEDIATE. The proportion of men, patients with diabetes mellitus and hypertension was higher among patients with SXscoreHIGH as well. Clinical indications for diagnostic coronary angiography were not remarkably different by the SXscore, but more patients in the SXscoreLOW-INTERMEDIATE had typical CAD symptoms and more patients without

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significant CAD had other symptoms. As expected, prevalence of multivessel disease and all markers of increased lesion complexity, such as the presence of total occlusions, bifurcations and small vessel disease, were significantly more frequent in the SXscoreHIGH category.

Procedures after index angiographyThe proportion of patients submitted to PCI, CABG

and valve replacement based on the index diagnostic angiography according to patient category is presented in Table 2. As expected, more patients with higher scores were submitted to CABG. Despite having no significant CAD based on angiographic assessment done for this study, 3.4% of patients were submitted to PCI.

Clinical outcomesThe cumulative incidence of clinical outcomes across

patient groups is shown in Table 2. All-cause death was significantly higher in SXscoreHIGH patients as compared with patients without significant CAD, 16.7% and 3.9% (p < 0.001), respectively. Cardiovascular death, non-fatal MI, and late revascularization were more frequent in the SXscoreHIGH as well. After adjustment for confounding

factors, all outcomes remained associated with the SXscore (Table 3). Risk ratios for MACE, cardiac death or non-fatal MI and non-fatal MI alone were significantly associated with SXscoreLOW-INTERMEDIATE as well. Patients in the SXscoreHIGH category had a 12.5 (95% CI: 5.1-30.6) higher chance of presenting the primary outcome than those without significant CAD. This finding was similar among men (10.1; 95% CI: 3.9-25.9) and women (11.5; 95% CI: 1.1-117.3). Further adjustment for index revascularization did not change the estimates significantly. After adjustment for confounding factors, the primary outcome was also associated with the SXscore as a continuous variable (HR 1.06; 95% CI: 1.04-1.08). The area under the ROC curve was 0.73 (95% CI: 0.68-0.79) (Figure 2).

MACE-free survival curves for patients according to SXscores are presented in Figure 3, showing that curves diverged immediately after angiography and further during follow-up. Risk ratios for MACE according to the number of diseased vessels, compared to none, were 6.9 (95% CI: 3.4-13.9) for one-vessel disease and 10.2 (5.2-20.1) for multivessel disease. Despite the intrinsic relationship of this classification and the SXscore, 42.0% of the patients with multivessel disease were classified in the SXscoreLOW-INTERMEDIATE category.

Table 1 – Baseline clinical characteristics

Baseline characteristics No significant CAD n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value

Age 59.1 ± 10.4 60.8 ± 9.6 63.6 ± 8.6 0.002

Male 234 (47.3) 226 (65.3) 39 (72.2) < 0.001

Diabetes mellitus 92 (18.6) 85 (24.6) 18 (33.3) 0.01

Current smoking 65 (13.2) 51 (15.0) 3 (5.6) 0.08

Hypertension 344 (69.8) 260 (76.5) 45 (83.3) 0.02

Symptoms of CAD only 128 (25.9) 115 (33.4) 14 (25.9) 0.05

With a positive noninvasive test 209 (42.2) 139 (40.2) 28 (51.9) 0.3

Valve disease with suspected CAD 14 (2.8) 3 (0.9) 1 (1.9) 0.14

Other complaints 46 (9.3) 13 (3.8) 1 (1.9) 0.002

Angiographic analysis*

Right dominance - 309 (89.3) 51 (94.4) 0.3

N°. lesions per patient - 1.8 ± 1.0 3.9 ± 1.5 < 0.001

Total occlusions - 88 (25.4) 41 (75.9) < 0.001

Bifurcations - 125 (36.1) 44 (81.5) < 0.001

Small vessels /diffuse disease - 68 (19.7) 26 (48.1) < 0.001

Left main - 13 (13.8) 13 (24.1) < 0.001

Left anterior descending - 218 (63.0) 47 (87.0) < 0.001

Left circumflex - 109 (31.5) 36 (66.7) < 0.001

Right coronary artery - 169 (48.8) 43 (79.6) < 0.001

One vessel disease - 196 (56.7) 4 (7.4) < 0.001

Multivessel disease or LM - 150 (43.3) 50 (92.6) < 0.001

Values are given as n (%) or mean ±SD. LM: left main; CAD: coronary artery disease. * Assessment using the SYNTAX score definitions.

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Table 2 – Treatment after the index angiography and cumulative clinical outcomes across patient categories

Type of procedure No significant CAD n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value

Interventions: < 0.001

Percutaneous Coronary Intervention 17 (3.4) 208 (60.3) 14 (25.9)

Coronary Artery Bypass Surgery 0 46 (13.3) 29 (53.7)

Isolated valve replacement* 78 (15.8) 4 (1.2) 0

No invasive intervention 400 (80.8) 88 (25.4) 11 (20.4)

All-cause death 16 (3.9) 11 (3.3) 9 (16.7) < 0.001

Cardiac death and MI 4 (1.0) 13 (3.9) 9 (16.7) < 0.001

Cardiovascular death 9 (2.2) 6 (1.8) 7 (13) < 0.001

MACE 9 (2.2) 53 (15.7) 11 (20.4) < 0.001

Values are given as n (%). * patients excluded from outcome analysis. MI: myocardial infarction; MACE: MI, cardiac death, and late revascularization.

Table 3 – Hazard ratios* for major clinical outcomes according to patient categories

Type of Event No significant CAD† n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value

All-cause death 1.0 0.8 (0.4-1.7) 4.3 (1.8-10.1) < 0.001

Cardiovascular death 1.0 0.7 (0.3-2.1) 5.7 (2.0-15.9) < 0.001

Cardiac death 1.0 1.3 (0.3-5.9) 11.8 (2.9-48.5) < 0.001

MACE‡ 1.0 7.2 (3.5-14.7) 12.5 (5.1-30.6) < 0.001

Cardiac death or MI 1.0 3.5 (1.1-10.8) 16.0 (4.9-52.9) < 0.001

MI 1.0 12.6 (1.6-98.3) 33.9 (3.7-308.0) 0.007

Late Revascularization 1.0 9.9 (4.2-23.4) 4.0 (0.8-20.0) < 0.001

MI: myocardial infarction. *Adjusted for age, sex and diabetes. †Reference category, ‡MACE: MI, cardiac death, and late revascularization.

DiscussionThis study demonstrated that, in patients submitted to

diagnostic angiography for suspected CAD, the SXscore was able to predict the primary endpoint of cardiac death, non-fatal MI and late revascularization, independently of age, sex, presence of diabetes and index revascularization. There was a 6% increased risk in having a MACE for each additional point in the score. Patients with SXscoreHIGH had a significantly increased risk for all-cause, cardiovascular and cardiac death.

Previous studies have shown the ability of the SXscore to predict MACE in different scenarios. LEADERS,9,10 SIRTAX11 and RESOLUTE8 studies included patients with acute coronary syndromes as well as patients submitted to elective PCI. MI-SYNTAXscore Study,12 STRATEGY and MULTISTRATEGY13 studies were done in patients with acute MI. The ACUITY7 trial included patients with acute coronary syndromes. Finally, Serruys et al. summarized the results of five studies, analyzing data from 6.508 patients, with the same results.14 Differently from our research, all of those studies included only patients submitted to percutaneous revascularization procedures, and none of them focused on patients with suspected or stable CAD. The group of patients without significant CAD, although many had CAD with diameter stenosis lesser than 50%,

served as the reference category to compare outcomes with those of patients in the SXscoreLOW-INTERMEDIATE and SXscoreHIGH categories. We understand that our proposal is different from the application originally proposed for the score, in which patients without lesions treatable with surgery or percutaneously are excluded, but it is in line with the objectives of the study.

The comparison of the SXscore performance with the traditional CAD anatomical scores was not explored in our investigation. The presence of positive SXscores (44.6%) was similar to the frequency of patients with significant CAD (47%) detected by quantitative angiographic analysis done in a proportion of the patients of our cohort.21 Traditional angiographic scores have also predicted the incidence of MACE in previous studies,2 but those scores do not take into account difficulties in performing myocardial revascularization. Despite their prognostic ability, they have not been incorporated to clinical practice, where the number of diseased vessels has been used to estimate the anatomical severity of disease. In this cohort, patients with one-vessel and multivessel disease had a risk for MACE approximately similar to the SXscore low-intermediate and high, respectively. Nonetheless, almost half of the patients with multivessel disease were classified in the SXscoreLOW-INTERMEDIATE category.

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Figure 2 – ROC curve for the SYNTAX score.

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

Sen

siti

vity

1-Speci�city

SYNTAX Score

AUC: 0.73 (95% CI 0.68–0.79)

Based on the results of the SYNTAX trial,5 in which patients with low SYNTAX scores had similar outcomes regardless of the type of revascularization, our findings have a clinical implication - patients who would otherwise be referred to CABG could also be revascularized percutaneously. Considering that visual characterization of multivessel disease leads to referring patients to surgical revascularization, calculation of the SXscore could better stratify patients who would indeed benefit from this procedure (SXscoreHIGH category).

In this study, patients underwent an elective procedure and, as a result, there was a large proportion of patients with no significant CAD, who might also have lesions below 50%. Those patients did not fulfill the criteria for a positive score and served as a comparison group. Therefore, patients were classified into two categories: 1 to 22, and equal to 23 or greater, which correspond to the later defined categories of low-intermediate (0-22) and high (23 or higher).6 The proportion of patients classified as SXscoreLOW-INTERMEDIATE and submitted to percutaneous revascularization was higher than patients submitted to surgical revascularization, which reflects the current clinical practice and complies with the findings of the 5-year follow-up of the randomized clinical SYNTAX trial.6 At the time the study was conducted, drug-eluting stents were not available for use in the Brazilian public health system. In addition, current evidence indicates surgical revascularization for patients with high SXscores.6 Patients with high surgical risk who were not deemed

eligible for surgical revascularization by surgeons received percutaneous treatment. There was an unexpected finding of 3.4% of patients without significant CAD who were submitted to PCI. Patients with non-obstructive CAD represent a large proportion of patients undergoing coronary angiography. Subjective evaluation of coronary anatomy associated with the clinical and noninvasive information might have influenced the decision-making process and could explain this finding.

Our study has some limitations and strengths that should be addressed. We restricted our analysis to anatomical criteria, considering neither left ventricular function nor myocardial ischemia and viability. Nonetheless, our patients did not have clinically unstable disease or classes III or IV heart failure, and the anatomical criteria frequently prevail to reach a therapeutic decision. In addition, a recent post-hoc analysis of the COURAGE trial has demonstrated that anatomical criteria and not ischemia burden were able to predict cardiovascular events.22 Although most follow-up procedures have been conducted in our hospital, different types of stents were implanted, which could affect the likelihood of stent thrombosis or reinterventions.23 However, analysis including only MI and cardiac death did not change the estimates. Exclusion of patients submitted to valve replacement did not change the results either. Another limitation is the number of events, which accounted for the large confidence intervals. Despite having investigated almost

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Figure 3 – Kaplan-Meier Curve for MACE according to patient category. CAD: coronary artery disease.

1,000 patients, more than 50% did not have significant CAD, which reflects real life practice of a tertiary center performing diagnostic angiographies. Studies with larger sample size and conducted at other centers are necessary to confirm our findings and their external validity. The high inter-observer reproducibility of the examiners is among the strengths of our investigation, similar to some24 but different from other studies.25,26 This performance could be explained by the extensive training in assessing SXscore done by the interventional cardiologists and the fact that both underwent training at the same hospital.

Clinical ImplicationsIn clinical practice, the number of epicardial vessels

with more than 50% stenosis is used to assess prognostic information, and angiographic scores are rarely used. Recently, the use of scores has been shown to improve the standardization of clinical decision-making. For instance, the EUROSCORE27 or the STS score28 are routinely used in the decision making process for the indication of CABG.29 For the management of multivessel CAD, current guidelines formally recommend the use of the SXscore as well as the EUROSCORE.30 Our data expand the indications of the SXscore for the prognostic evaluation of patients referred for diagnostic angiography.

ConclusionIn conclusion, in patients with suspected CAD submitted

to elective coronary angiography, SXscore independently predicts MACE. Its routine use in this setting could identify patients with worse prognosis.

AcknowledgementsThis study was partially supported by the National Council

for Scientific and Technological Development (CNPq), Brazil; Research Funding of Hospital de Clínicas de Porto Alegre (FIPE-HCPA), Porto Alegre, Brazil.

Author contributionsConception and design of the research: Fuchs FC, Ribeiro

JP, Fuchs FD, Moreira LB, Fuchs SC; Acquisition of data: Fuchs FC, Wainstein MV, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC; Analysis and interpretation of the data and Critical revision of the manuscript for intellectual content: Fuchs FC, Ribeiro JP, Fuchs FD, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC, Moreira LB, Fuchs SC;Statistical analysis and Writing of the manuscript: Fuchs FC, Ribeiro JP, Fuchs FD, Fuchs SC; Obtaining financing: Ribeiro JP, Moreira LB, Fuchs SC.

Potential Conflict of InterestNo potential conflict of interest relevant to this article

was reported.

Sources of FundingThis study was partially funded by CNPq and Fundação para

o incentivo em Pesquisa do Hospital de Clínicas de Porto Alegre.

Study AssociationThis article is part of the thesis of master submitted by

Felipe C. Fuchs, from Faculdade de Medicina da Universidade Federal do Rio Grande do Sul.

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1. Emond M, Mock MB, Davis KB, Fisher LD, Holmes DR Jr, Chaitman BR, et al. Long–term survival of medically treated patients in the Coronary Artery Surgery (CASS) Registry. Circulation. 1994;90(6):2645-57.

2. Ringqvist I, Fisher LD, Mock M, Davis KB, Wedel H, Chaitman BR, et al. Prognostic value of angiographic indices of coronary artery disease from the coronary artery surgery study (CASS). J Clin Invest. 1983;71(6):1854-66.

3. Fihn SD, Blankenship JC, Alexander KP, Bittl JA, Byrne JG, Fletcher BJ, et al. 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update of the guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, and the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2014;130(19):1749-67.

4. Sianos G, Morel MA, Kappetein AP, Morice MC, Colombo A, Dawkins K. The SYNTAX score: an angiographic tool grading the complexity of coronary artery disease. EuroIntervention. 2005;1(2):219-27.

5. Serruys PW, Morice MC, Kappetein AP, Colombo A, Holmes DR, Mack MJ, et al; SYNTAX Investigators. Percutaneous coronary intervention versus coronary–artery bypass grafting for severe coronary artery disease. N Engl J Med. 2009;360(10):961-72. Erratum in: N Engl J Med. 2013;368(6):584.

6. Mohr FW, Morice MC, Kappetein AP, Feldman TE, Ståhle E, Colombo A, et al. Coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with three-vessel disease and left main coronary disease: 5-year follow-up of the randomised, clinical SYNTAX trial. Lancet. 2013;381(9867):629-38.

7. Palmerini T, Genereux P, Caixeta A, Cristea E, Lansky A, Mehran R, et al. Prognostic value of the SYNTAX score in patients with acute coronary syndromes undergoing percutaneous coronary intervention: analysis from the ACUITY (Acute Catheterization and Urgent Intervention Triage StrategY) trial. J Am Coll Cardiol. 2011;57(24):2389-97.

8. Garg S, Serruys PW, Silber S, Wykrzykowska J, van Geuns RJ, Richardt G, et al. The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial. JACC Cardiovasc Interv. 2011;4(4):432-41.

9. Wykrzykowska JJ, Garg S, Girasis C, de Vries T, Morel MA, van Es GA, et al. Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial. J Am Coll Cardiol. 2010;56(4):272-7.

10. Wykrzykowska JJ, Garg S, Onuma Y, de Vries T, Morel MA, van Es GA, et al. Implantation of the biodegradable polymer biolimus–eluting stent in patients with high SYNTAX score is associated with decreased cardiac mortality compared to a permanent polymer sirolimus–eluting stent: two year follow–up results from the “all–comers” LEADERS trial. EuroIntervention. 2011;7(5):605-13.

11. Girasis C, Garg S, Räber L, Sarno G, Morel MA, Garcia-Garcia HM, et al. SYNTAX score and Clinical SYNTAX score as predictors of very long–term clinical outcomes in patients undergoing percutaneous coronary interventions: a substudy of SIRolimus–eluting stent compared with pacliTAXel–eluting stent for coronay revascularization (SIRTAX) trial. Eur Heart J. 2011;32(24):3115-27.

12. Magro M, Nauta S, Simsek C, Onuma Y, Garg S, van der Heide E, et al. Value of the SYNTAX score in patients treated by primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: the MI SYNTAXscore study. Am Heart J. 2011;161(4):771-81.

13. Garg S, Sarno G, Serruys PW, Rodriguez AE, Bolognese L, Anselmi M, et al; STRATEGY and MULTISTRATEGY Investigators. Prediction of 1–year clinical outcomes using the SYNTAX score in patients with acute ST–segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a substudy of the STRATEGY (Single High–Dose Bolus Tirofiban and Sirolimus–Eluting Stent Versus Abciximab and Bare–Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High–Dose Bolus Tirofiban Versus Abciximab With Sirolimus–Eluting Stent or Bare–Metal Stent in Acute Myocardial Infarction Study) trials. JACC Cardiovasc Interv. 2011;4: 66-75.

14. Garg S, Sarno G, Girasis C, Vranckx P, de Vries T, Swart M, et al. Patient level pooled analysis assessing the impact of the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) Score on 1–year clinical outcomes in 6,508 patients enrolled in contemporary coronary stent trials. JACC Cardiovasc Intverv. 2011;4(6):645-53.

15. Go AS, Mozaffarian D, Roger VL, Benjamin EJ, Berry JD, Borden WB, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics--2013 update: a report from the American Heart Association. Circulation. 2013;127(1):e6-e245. Erratum in: Circulation. 2013;127(23):e841.

16. SYNTAX Working Group. SYNTAX score calculator. [Accessed in 2015 Nov 10]. Available from: http://www.syntaxscore.com

17. Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD; Writing Group on the Joint ESC/ACCF/AHA/WHF Task Force for the Universal Definition of Myocardial Infarction. Third universal definition of myocardial infarction. Eur Heart J. 2012;33(20):2551-67.

18. Murray CJ, Lopez AD, Feehan DM, Peter ST, Yang G. Validation of the symptom pattern method for analyzing verbal autopsy data. PLoS Med. 2007;4(11):e327.

19. Fleiss JL, Cohen J. The equivalence of weighted Kappa and the intraclass correlation coefficient as measures of reliability. Educational and Psychological Measurement. 1973;33:613-9.

20. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, et al. Standards for Reporting of Diagnostic Accuracy. The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration. Ann Intern Med. 2003;138(1):W1-12.

21. Riedner CE, Rhoden EL, Fuchs SC, Wainstein MV, Gonçalves SC, Wainstein RV, et al. Erectile dysfunction and coronary artery disease: an association of higher risk in younger men. J Sex Med. 2011;8(5):1445-53.

22. Mancini GB, Hartigan PM, Shaw LJ, Berman DS, Hayes SW, Bates ER, et al. Predicting Outcome in the COURAGE Trial: Coronary Anatomy Versus Ischemia. JACC Cardiovasc Interv. 2014;7(2):195-201.

23. Wallace EL, Abdel-Latif A, Charnigo R, Moliterno DJ, Brodie B, Matnani R, et al. Meta-analysis of long-term outcomes for drug-eluting stents versus bare-metal stents in primary percutaneous coronary interventions for ST-segment elevation myocardial infarction. Am J Cardiol. 2012;109(7):932-40.

24. Garg S, Girasis C, Sarno G, Goedhart D, Morel MA, Garcia-Garcia HM, et al. SYNTAX trial investigators. The SYNTAX score revisited: a reassessment of the SYNTAX score reproducibility. Catheter Cardiovasc Interv. 2010;75(6):946-52.

25. Tanboga IH, Ekinci M, Isik T, Kurt M, Kaya A, Sevimli S. Reproducibility of syntax score: from core lab to real world. J Interv Cardiol. 2011;24(4):302-6.

26. Généreux P, Palmerini T, Caixeta A, Cristea E, Mehran R, Sanchez R, et al. SYNTAX score reproducibility and variability between interventional cardiologists, core laboratory technicians, and quantitative coronary measurements. Circ Cardiovasc Interv. 2011;4(6):553-61.

27. Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R. European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg. 1999;16(1):9-13.

28. Shroyer AL, Coombs LP, Peterson ED, Eiken MC, DeLong ER, Chen A, et al; Society of Thoracic Surgeons. The Society of Thoracic Surgeons: 30–day operative mortality and morbidity risk models. Ann Thorac Surg. 2003;75(6):1856-65.

29. Metzler B, Winkler B. SYNTAX, STS and EuroSCORE – How good are they for risk estimation in atherosclerotic heart disease? Thromb Haemost. 2012:108(6):1065-71.

30. Windecker S, Kolh P, Alfonso F, Collet JP, Cremer J, Falk V, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J. 2014;35(37):2541-619.

References

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Original Article

Effects of Air Pollutant Exposure on Acute Myocardial Infarction, According to GenderTássia Soldi Tuan1,Taís Siqueira Venâncio1,Luiz Fernando Costa Nascimento1,2

Departamento de Medicina – Universidade de Taubaté1,Taubaté, SP; Departamento de Energia – Universidade Estadual Paulista – Campus de Guaratinguetá2,Guaratinguetá, SP – Brazil

Mailing Address: Luiz Fernando Costa Nascimento •Universidade Estadual Paulista – Campus de Guaratinguetá. Av Ariberto Pereira da Cunha, 333. Postal Code 12516-410, Guaratinguetá, SP – BrazilE-mail: [email protected] received November 23, 2015; revised April 27, 2016; accepted May 03, 2016.

DOI: 10.5935/abc.20160117

Abstract

Background: There is evidence of the effects of air pollution on hospital admissions due to cardiovascular diseases, including myocardial infarction.

Objective: To estimate the association between exposure to air pollutants and hospital admissions due to myocardial infarction according to gender, between January 1st 2012 and December 31st 2013, in São Jose dos Campos-SP.

Methods: An ecological time series study was carried out with daily data of admissions due to AMI, pollutants CO, O3, PM10, SO2, and NO2, according to gender. We used the Poisson regression generalized linear model to estimate the relative risks of hospital admissions with lags of 0-5 days, adjusted for temperature, humidity, seasonality and days of the week.

Results: There were 1837 admissions for ischemic heart diseases, with 636 women and 1201 men. For females, the risks were significant for CO in lag 0 (RR = 1,09), lag1 (RR = 1,08) and lag 5 (RR = 1,10) and SO2 in lag 0 (RR = 1,10) and 3 (RR = 1,09). For men there was significance of the CO in, lag 3 and lag 5 (RR = 1,05). There was significance, regardless of gender, for CO at lag 1 (RR = 1,05) and lag 5 (RR = 1,07) and lag 0 for SO2 (RR = 1,06).

Conclusion: The data presented show the important role of CO and SO2 in the genesis of myocardial infarction admissions, and responses to pollutant exposure are different if analyzed by gender and together - hence the importance of a stratified analyses. (Arq Bras Cardiol. 2016; 107(3):216-222)

Keywords: Myocardial Infarction; Environmental Pollutants; Gender Identity; Sulfur Dioxide; Carbon Monoxide.

IntroductionGreat evidence indicating that air pollution in our

environment is enough to cause health damages, and the need to define regulatory process regarding air quality standards make it pivotal to better outline this association, identifying special population groups, specific pathologies, and environmental levels that lead to the exposure-disease process and death. Accordingly, information from systematic investigations with locally generated data are of great importance to subsidise planning and assessment of health care programs focused on this issue.1

Cardiovascular diseases are still the main cause of death in Brazil, accounting for almost 32% of all deaths. Moreover, it is the third leading cause of hospital admissions in the country. Among them, acute myocardial infarction is still one of the primary causes of morbidity and mortality. The study of acute myocardial infarction (AMI) is essential due to its high

prevalence, morbidity and mortality. Epidemiological studies show general mortality rates of around 30%, with half of deaths occurring in the first two hours of the event, and 14% of patients dying before receiving medical treatment.2

In Brazil, in 2014, 95,000 hospital admissions for acute myocardial infarction were recorded; in the state of São Paulo, there were 27,000 (http://tabnet.datasus.gov.br/cgi/tabcgi.exe?sim/cnv/obt10uf.def).3

Studies from metropolitan areas and mid-sized cities have shown an association between admissions for AMI and exposure to air pollutants, with particulate matter (PM10), ozone (O3), sulphur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) as the ones most highly associated to admissions for AMI.1,4-16

Carbon monoxide, which is still understudied, is released into the atmosphere by natural sources (volcanic activity, electrical discharges and natural gas emissions) and as a product of incomplete combustion of fossil fuels, heating systems, thermal coal plants, biomass and tobacco burning. Its significance lies in its affinity for hemoglobin, which is 240 greater than oxygen’s.

Further epidemiological evidence that has been growing in different studies is the categorization by gender. Several studies show more pronounced effects in women than in men, but literature is still inconsistent in regards to that. Just as the outcome of hospital admission, there’s also evidence of higher mortality in women in percutaneous coronary interventions.5

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Arq Bras Cardiol. 2016; 107(3):216-222

Several studies in areas such as The USA, Canada, and Europe show gender differences, varying according to age, in mortality from AMI and a higher risk of death in younger women compared to their male counterparts, and also different effects of risks in hospital admission due to respiratory diseases.6-17

The aim of this study is to estimate the association between exposure to air pollutants and hospital admissions for AMI (in individuals over 50 years of age), categorized by gender, between January 1st 2012 and December 31st 2013, in the city of São José dos Campos – SP.

MethodsEcological time series study with data relative to hospital

admissions for AMI (ICD-10 from J20.0 to J24.0) in individuals of both genders, over 50 years of age, residents of São José dos Campos, SP. The study period was between January 1st, 2012 and December 31st, 2013. Admission data were obtained from the DATASUS portal.3 All actions carried out during the period of admission must be notified to the Brazilian Unified Health System (Sistema Único de Saúde – SUS) via a Hospital Admission Authorization (AIH), which is registered and filed, and payment to service providers for the procedures are made by SUS. Among the variables obtained in this portal, the ones used were relative to patients’ gender, age (in years) and main diagnosis.

Place of StudySão José dos Campos is a Brazilian municipality in the

interior of the state of São Paulo, in the mesoregion of Vale do Paraíba Paulista, 84 km east of the capital of the state. It houses 650,000 people, and has a 130,000 vehicle fleet per day, of which only the minority are heavy (buses and trucks). It is an important economic center with companies in the fields of technology, education and research centers. Its geographical location is 23°11’ S, 45°53’W.

Studied pollutants were PM10, SO2, O3, NO2 (µg/m3) and CO (ppb), and values of PM10, SO2, NO2 and CO were quantified by daily averages, and values for O3 were from a maximum of 8 hours. Such values were quantified by the Environmental Company of the State of São Paulo (CETESB),18 which relies on a measuring station in São José dos Campos, as well as information on minimum, mean, and maximum temperatures, relative air humidity, seasonality, and days of the week. From those data, minimum temperature and relative air humidity were used.

Hospital admission is a counting, discreet event for which the Poisson Regression is indicated to estimate the relative risks of exposure in the outcome – hospital admission. A data bank was built with daily admission data, for each pollutant and climatic variable. Lags of 0-5 days were considered because the effects of exposure to pollutants may be evidenced not only on the same day, but also days after exposure. Thus, a Poisson regression generalized linear model (GLM) was selected. Models with an isolated pollutant and with four pollutants simultaneously were built, adjusted by the minimum temperature, relative air humidity, seasonality, and days of the week. The analyses were carried out considering females, males, and both genders to identify possible differences in the relative risks for hospital admission

for infarction, according to these strata. Pearson correlation values were obtained among the independent variables and presented in a table.

For the analysis, we used the software Stata V10. Coefficients provided by the Poisson Regression were transformed into relative risks (RR) with respective confidence intervals of 95%. In the case of significant association between exposure to a certain pollutant and hospital admission, we considered increases (AUM-RR) of 300 ppb for CO, and 2µg/m3 for SO2 expressed in percentage points, according to the expression AUM-RR (%) = (exp(coef * AUM) -1)*100, in which coef is the numeric value of the coefficient provided by the Poisson Regression and AUM are the above values considered for CO and SO2. The variables were presented with the value of their means and respective standard deviations in a table.

Counsel from the Ethics Committee was waived since this is an ecological study and the data is publically available on the net, and also because of the impossibility to identify the subject of the analysis. The significance level adopted was of alpha = 5%.

ResultsA total of 1837 individuals were admitted for ischemic

heart diseases, of which 636 (34.6%) were women, and 1201 (65.4%) were men. The mean concentration of the pollutants (µg/m3), standard deviation, minimum and maximum are depicted in table 1.

Table 2 presents the correlation matrix between the study variables (environmental pollutants, climatic variables, and number of admissions) for both genders. Strong correlations between pollutants were observed, except for O3 and CO.

Exposure to pollutants, considering the increase in their concentrations of 300 ppb, was associated to CO in both genders in lags 1 (RR = 1.05) and 5 (RR = 1.07); in women in lags 0 (RR = 1.09), 1 (RR = 1.08), and 5 (RR = 1.10); and in men in lags 3 (RR = 1.06) and 5 (RR = 1.05). For SO2, the effects were observed in both genders in lag 0 (RR = 1.06); in women in lags 0 (RR = 1.10) and 3 (RR = 1.09); and no exposures with statistical significance were identified in men.

From the values obtained from the generalized linear model and its standard deviations, the confidence interval for the relative risk of admission for acute myocardial infarction was calculated.

With an increase of 300 ppb for CO, relative risks and respective confidence intervals (CI 95%) are in Figure 1 for both genders, leading to an increase of 10 percentage points for women, and up to 7 points when both genders are analysed. In the case of SO2, as shown in Figure 2, the increase of 2,0 µg/m3 implied an increase of up to 5 percentage points for both genders, up to 100 pp for women, and non-significant for men.

DiscussionThis study, to the best of our knowledge, is the first to

analyse stratified exposure by gender – it identified the importance of exposure to CO and SO2 in the genesis of hospital admissions for ischemic heart diseases, in individuals

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Table 1 – Descriptive analysis of study variables: Mean, standard deviation (sd), minimum and maximum values (Min – Max). São José dos Campos-BR, 2012-2013

Variables Mean (sd) Min – Max

Admissions 2.5 (1.8) 0.0 -- 9.0

PM10 (µg/m3) 22.6 (10.5) 6.0 -- 81.0

O3 (µg/m3) 74.1 (34.4) 1.0 -- 213.0

CO (ppb) 883 (459) 200 -- 3400

SO2 (µg/m3) 2.7 (2.3) 0.0 -- 29.0

NO2 (µg/m3) 48.2 (17.7) 11.0 -- 112.0

Humidity % 57.4 (16.4) 24.0 -- 99.0

Minimum temperature ºC 15.6 (3.5) 4.4 -- 21.9

Table 2 – Pearson correlation matrix between atmospheric variables for both genders. São José dos Campos, São Paulo, 2012/2013

Min. Temp.# RH PM10 SO2 CO O3 NO2

Min. Temp 1

RH 0.143** 1

PM10 -0.308** -0.329** 1

SO2 -0.058 -0.084* 0.167** 1

CO -0.288** 0.001 0.360** 0.099* 1

O3 0.197** -0.480** 0.149** 0.220** 0.037 1

NO2 -0.410** -0.169** 0.517** 0.128** 0.358** 0.171** 1

Min. Temp: minimum temperature; RH: relative air humidity. * p-value r < 0.05 **p-value r < 0.01.

over 50 years old, in the city of São José dos Campos, separating the individuals by gender. For CO, the effects were evident 1 and 5 days after exposure when both genders were analysed; stratifying admissions, they occurred on the same day, 1, and 5 days after exposure for women, and 3 and 5 days after exposure for men. In relation to SO2, effects were evident in lag 0 for both genders, lag 0 and 3 for women, and with no statistical difference for men.

Considering this is a multipollutant model, other pollutants were analysed, but no association was found for them.

The categorization by gender has been approached in several studies, showing epidemiological significance, but there are still no studies with a biological explanation.

According to Clougherty17, several studies suggest that the response to air pollutant exposure differs for men and women, or for boys and girls. The explanation, however, is still unclear, while modifications are observed as a result of biological differences linked to gender (e.g., hormones and body size) or gender differences in activity patterns, coexposure, or exposure quantification accuracy. Numerous modifications consist of the modification of these two factors (exposure pattern and biological response).

An association between exposure to SO2 and cardiovascular diseases, especially deaths by stroke, was shown in São José dos Campos, associated to ozone pollutants and particulate matter, in individuals over 50 years of age. SO2 concentrations

were 4 µg/m3.7 In a study in São Paulo, exposure to SO2 was associated to admissions for circulatory and ischemic heart diseases,1 as the effects were similar to the CO exposure, but with greater intensity. Sunyer et al. have also shown the association of SO2 exposure and cardiovascular diseases in seven European cities. Concentrations of the pollutant were between 5 and 21 µg/m3, and increases of 10 µg/m3, in these concentrations, implicated in significant increases between 0.7% and 1.2% in the number of hospital admissions for cardiovascular diseases, especially ischemic heart diseases.8 Atkinson et al.9 showed the significant effect of SO2 exposure in isolation and adjusted by gender, age, smoking habit, BMI, and comorbidities such as diabetes and arterial hypertension in hospital admissions for acute myocardial infarction, stroke, arrhythmias and heart failure.

SO2 exposure was also significant in admissions for CVD with or without diabetes.10 Our study also showed that increases of 2 µg/m3 in SO2 concentrations, adjusted by concentration of other pollutants, implicate in a significant increase in risk for women (RR = 1.10), which contributed to high risk rates in the absence of stratification by gender. That is, when assessed for both genders (RR = 1.06) because the effects of exposure were not significant for men.

In this study, CO exposure, in São José dos Campos, was also significant for admissions for AMI. Such findings are in accordance with those found by Gouveia et al.,1 when

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Figure 1 – Relative risk for CO exposure according to lag 0 to lag 5 for males (M), females (F), and both genders (B). São José dos Campos. 2012-2013.

1.20

1.10

1.00

RR

0.90

M F B M F B M F B M F B M F B M F B

LAG 0 LAG 1 LAG 2 LAG 3 LAG 4 LAG 5

concentrations were 3240 ppb, reaching a maximum of 12600 ppb, values far above the ones observed in São José dos Campos, which had a mean of 883 ppb, and a maximum of 3400 ppb. Risks observed in São Paulo, according to an increase of 1000 ppb in CO concentrations were RR = 1.016, and the most significant discrepancy was a moving average of 2 days. CO exposure was significant to emergency services for cardiovascular diseases with or without diabetes. This association was more evident on the same day as exposure (lag 0) in non-diabetic individuals.10

In a study done in Chicago, CO effect on admissions for heart failure was dependent on temperature, with the magnitude of the effect increasing as the temperature dropped.11 Carbon monoxide concentration recorded on the day of admissions showed, among the pollutants, the strongest and most consistent association with hospital admission rates, simultaneously adjusting to temperature, dew point, and other air pollutants, for a change of 1000 ppb to 3000 ppb, interquartile interval, and relative risk of RR = 1.065 (CI 95% = 1.028-1.104).12

Figure 2 – Relative risk for SO2 exposure according to lag 0 to lag 5 for males (M), females (F), and both genders (B). São José dos Campos. 2012-2013.

M F B M F B M F B M F B M F B M F B

LAG 0 LAG 1 LAG 2 LAG 3 LAG 4 LAG 5

1.20

1.10

1.00

0.90

0.80

RR

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A study developed in China analysed a sample of patients with acute myocardial infarction in several Chinese hospitals in 2001, 2006, and 2011, and showed that in-hospital mortality rate was higher among women than men (17.2% vs 9.1%; p < 0.01; OR 2.07; 95% IC 1.85–2.33). Odds ratio not adjusted for mortality in women, in comparison to men, was of 2.20 (95% CI 1.59–3.04); 2.21 (95% CI 1.74–2.79); 1.37 (95% CI 1.15–1.65); and 1.25 (CI 95% 0.97–1.63) for the ages <60; 60-69; 70-79 and ≥ 80 years, respectively. After adjusting to the characteristic of patients, hospital and year of study, OR for mortality, comparing men and women, was 1.69 (95% CI 1.01–2.83); 1.64 (95% CI 1.24–2.19); 1.15 (CI 95% 0.90–1.46); and 0.82 (95% CI 0.60–1.11) for the ages <60; 60–69; 70–79; and ≥ 80 years, respectively. Gender-age interaction for mortality was statistically significant (p = 0.009), even after adjustment for a wide range of confounders, and did not vary over time or in rural/urban areas.6

The associations between SO2 and CO and admissions for AMI are in keeping with the findings of Koken et al.13 associating SO2 to an increase in hospital admissions for cardiac arrhythmias, and CO significantly associated to admissions for congestive heart failure. Additionally, they found more hospital admissions for cardiovascular diseases in men than in women.

A study done in São Paulo found greater effects of air pollution on congestive heart failure in men, and on cardiovascular and ischemic heart diseases in women. This reinforces the need for additional studies focusing on the modification of air pollution effects on health by gender.14 Kan et al.15 showed that effects of air pollutant exposure, SO2 amongst them, were more evident in women. An increased risk of death by stroke was found in older women after PM10 exposure.15,16

On the other hand, Cakmak et al.19 did not find a significant association between cardiac disease and air pollution that was influenced by gender. In another study, according to a gender stratified analysis, no statistically significant difference was found between pollutants and mortality from cardiovascular diseases (CVD) in women, and among men, only NO2 was significantly associated to mortality from CVD.20 Zeka et al.21 identified a smaller effect of exposure to PM10 in mortality from cardiovascular diseases in women over 60 than in men in the same age group. A possible explanation for that would be hormonal. In post-menopausal women (over 60), with PM10 exposure, mortality risk from cardiac diseases was five times higher than in pre-menopausal women. However, men in the same age groups, presented a risk two times higher in the over 60 group.22 A study developed in Shanghai about the role of air pollutants in daily mortality showed that SO2 and NO2 exposure effects in mortality were slightly higher in women than in men. The mean concentration of SO2 was 45 µg/m3 and of NO2, 67 µg/m3; carbon monoxide was not included in this study.15

Chen et al.23 found risk of death from coronary disease (CD), stemming from PM10 and PM2.5 exposure, that was significantly

higher in women than in men, in the analysis of a single pollutant as well as in the multipollutant analysis. SO2 exposure was not associated to death from CD. A reason for such finding would be that PM10 and PM2.5 deposition is more localized and more intense in women than in men – the smaller number of red cells in women might make them more sensitive to the toxic effects of air pollutants.23

In a study with over 65,000 post-menopausal women, exposure to fine particulates was associated to the incidence of cardiovascular disease and death.

LimitationsThis study may have limitations, among which are the own

limitations of ecological studies. It is not possible to point out the causality between exposure and outcomes other than to point out associations between exposure and outcomes. It is not possible to identify if the admitted individual was exposed and if the exposed individual was admitted. There may error in diagnoses recorded on Datasus, leading to sub-notations and over-notations in cases of infarction. However, Datasus is an official, reliable and widely used source in the areas of air pollutant exposure effects and illness. We also did not include hospital admissions through health plans or health insurance. It is worth noting that Datasus does not contemplate information on factors or comorbidities associated to ischemic heart diseases such as smoking, overweightness and obesity, hypercholesterolaemia, and previous diseases of the circulatory system. Concentrations were considered homogenous in the entire city, and it was assumed that exposures happened homogeneously and that people had free movement around the city.

Despite these limitations, other than pointing out the risks of air pollutant exposure in the genesis of admissions for myocardial infarction in a mid-sized city, the importance of the study lies in the fact that there are differences in the responses to pollutant exposure according to gender, and that analyses involving air pollutant exposure and circulatory diseases stratified by gender must be adopted.

ConclusionsThis study revealed that the global impact assessment of air

pollution on health, through time series studies, is important to strengthen the implementation of environmental health surveillance by the health sector. The results show the direct estimate of population illness due to a variation of atmospheric pollutant concentrations. It is suggested that preventive and educational measures, through the media, keep the population informed about environmental pollution conditions, as well as the optimal places for leisure and sports.

AcknowledgementsTássia Soldi Tuan would like to thank São Paulo Research

Foundation (FAPESP) for the granted scholarship (process 2014/11656-7).

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1. Gouveia N, Freitas CU, Martins LC, Marcilio IO. Respiratory and cardiovascular hospitalizations associated with air pollution in the city of São Paulo, Brazil. Cad Saúde Pública. 2006;22(12):2669-77.

2. Pesaro AE, Serrano Jr CV, Nicolau JC. Infarto agudo do miocárdio: síndrome coronariana aguda com supradesnível do segmento ST. Rev Assoc Med Bras. 2004;50(2):214-20.

3. Ministério da Saúde. Departamento de Informações e Informática do Sistema Único de Saúde, DATASUS. [Citado em 2015 Dez 12]. Disponível em: http://w3.datasus.gov.br/datasus/index.php.

4. Nascimento LF. Air pollution and cardiovascular hospital admissions in a medium-sized city in São Paulo State, Brazil. Braz J Med Biol Res. 2011;44(7):720-4.

5. Piegas LS, Haddad N. Percutaneous coronary intervention in Brazil: results from the Brazilian Public Health System. Arq Bras Cardiol. 2011;96(4):317-24.

6. Zheng X, Dreyer RP, Hu S, Spatz ES, Masoudi FA, Spertus JA, et al; China PEACE Collaborative Group. Age-specific gender differences in early mortality following ST-segment elevation myocardial infarction in China. Heart. 2015;101(5):349-55.

7. Amancio CT, Nascimento LF. Association of sulfur dioxide exposure with circulatory system deaths in a medium-sized city in Brazil. Braz J Med Biol Res 2012;45(11):1080-5.

8. Sunyer J, Ballester F, Tertre AL, Atkinson R, Ayres JG, Forastiere F, et al. The association of daily sulfur dioxide air pollution levels with hospital admissions for cardiovascular diseases in Europe (The APHEA-II study). Eur Heart J. 2003;24(8):752-60.

9. Atkinson RW, Carey IM, Kent AJ, van Staa TP, Anderson HR, Cook DG. Long-term exposure to outdoor air pollution and incidence of cardiovascular diseases. Epidemiology. 2013;24(1):44-53. Erratum in: Epidemiology. 2013;24(2):339.

10. Pereira Filho MA, Pereira LA, Arbex FF, Arbex M, Conceição GM, Santos UP, et al. Effect of air pollution on diabetes and cardiovascular diseases in São Paulo, Brazil. Braz J Med Biol Res. 2008;41(6):526-32.

11. Morris RD, Naumova EN. Carbon monoxide and hospital admissions for congestive heart failure: evidence of an increased effect at low temperatures. Environ Health Perspect. 1998;106(10):649-53.

12. Burnett RT, Dales RE, Brook JR, Raizenne ME, Krewski D. Association between ambient carbon monoxide levels and hospitalizations for congestive heart failure in the elderly in 10 Canadian cities. Epidemiology. 1997;8(2):162-7.

13. Koken PJ, Piver WT, Ye F, Elixhauser A, Olsen LM, Portier CJ. Temperature, air pollution, and hospitalization for cardiovascular diseases among elderly people in Denver. Environ Health Perspect. 2003;111(10):1312-7.

14. Martins LC, Pereira LA, Lin CA, Santos UP, Prioli G, Luiz Odo O, et al . The effects of air pollution on cardiovascular diseases: lag structures. Rev Saúde Pública. 2006;40(4):677-83.

15. Kan H, London SJ, Chen G, Zhang Y, Song G, Zhao N, et al. Season, Sex, age, and education as modifiers of the effects of outdoor air pollution on daily mortality in Shanghai, China: the public health and air pollution in Asia (PAPA) Study. Environ Health Perspect. 2008;116(9):1183-8.

16. Hong YC, Lee JT, Kim H, Ha EH, Schwartz J, Christiani DC. Effects of air pollutants on acute stroke mortality. Environ Health Perspect 2002;110(2):187-91.

17. Clougherty JE. A growing role for gender analysis in air pollution epidemiology. Cien saúde colet. 2011;16(4):2221-38.

18. São Paulo (Estado). Companhia Estadual de Tecnologia de Saneamento Básico e Defesa do Meio Ambiente (CETESB). [Citado em 2015 Dez 12]. Disponivel em: http://www.cetesb.sp.gov.br

19. Cakmak S, Dales RE, Judek S. Do gender, education, and income modify the effect of air pollution gases on cardiac disease? J Occup Environ Med. 2006;48(1):89-94.

20. Liu Y, Chen X, Huang S, Tian L, Lu Y, Mei Y, et al. Association between Air Pollutants and Cardiovascular Disease Mortality in Wuhan, China Int. J Environ Res Public Health. 2015;12(4):3506-16.

21. Zeka A, Zanobetti A, Schwartz J. Individual-level modifiers of the effets of particulate matter on daily mortality. Am J Epidemiol. 2006;163(9):849-59.

22. Miller KA, Siscovick DS, Sheppard L, Shepherd K, Sullivan JH, Anderson GL, et al. Long-term exposure to air pollution and incidence of cardiovascular events in women. N Engl J Med. 2007;356(5) :447-58.

23. Chen LH, Knutsen SF, Shavlik D, Beeson WL, Petersen F, Ghamsary M, et al. The association between fatal coronary heart disease and ambient particulate air pollution: are females at greater risk? Environ Health Perspect. 2005;113(12):1723-9. Erratum in: Environ Health Perspect. 2006;114(1):A21.

References

Author contributionsConception and design of the research, Acquisition of

data, Analysis and interpretation of the data, Writing of the manuscript and Critical revision of the manuscript for intellectual content: Tuan TS, Venâncio TS, Nascimento LFC; Statistical analysis: Nascimento LFC.


was reported.

Sources of Funding

There were no external funding sources for this study.

Study Association

This study is not associated with any thesis or dissertation work.

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Original Article

Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated ArteriesDaniela Medeiros Lobo de Andrade1, Leonardo Luis Borges2, Ieda Maria Sapateiro Torres1, Edemilson Cardoso da Conceição2, Matheus Lavorenti Rocha1

Laboratório de Farmacologia Cardiovascular – Faculdade de Farmácia - Universidade Federal de Goiás (UFG)1; Laboratório de Pesquisa em Produtos Naturais – Faculdade de Farmácia – Universidade Federal de Goiás (UFG)2; Goiânia, GO – Brazil

Mailing Address: Matheus Lavorenti Rocha •UFG – Faculdade de Farmácia. Rua 240, esquina com 5ª Avenida, s/n, Setor Leste Universitário. Postal Code 74605-170, Goiânia, Goiás – Brazil.E-mail: [email protected], [email protected] received November 25, 2015; revised manuscript March 04, 2016; accepted March 07, 2016.

DOI: 10.5935/abc.20160118

Abstract

Background: Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified.

Objectives: To determine the effects of jabuticaba hydroalcoholic extract (JHE) on vascular smooth muscle (VSM) of isolated arteries.

Methods: Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed.

Results: Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL). Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine) hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM).

Conclusion: JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect. (Arq Bras Cardiol. 2016; 107(3):223-229)

Keywords: Jabuticaba (Myrciaria Cauliflora); Trees; Vasodilatation; Calcium Channels; Muscle, Smooth Vascular.

IntroductionCardiovascular diseases are a major cause of death

worldwide, among which hypertension accounts for 9.4 million deaths per year.1 Around 1 billion adults in the world have hypertension, and that figure will have increased by 25% in 10 years.2

Vascular tonus regulation is fundamental to appropriate blood pressure control. Blood vessel contraction and dilation in response to physiological demands are controlled by changes in the intracellular concentration of Ca2+ in vascular smooth muscle (VSM) cells. The increase in intracellular concentration of Ca2+ occurs via both Ca2+ influx through the plasma membrane and Ca2+ release from inner sources, such as the sarcoplasmic reticulum.3,4 Effective drugs to blood pressure control, such as

nifedipine, verapamil and diltiazem, which act as Ca2+ channel blockers, induce vasodilation and reduce blood pressure.5

The use of natural products as an alternative treatment for hypertension has been extensively studied, being known to induce hypotension with minimum side effects.6,7 Jabuticaba (Myrciaria cauliflora), also known as Brazilian grape, is a hard-skinned berry of the Myrtaceae family, largely distributed in Brazil. It can be consumed fresh or in the form of liqueurs, wines, jams and sweets, and its consumption has increased in Brazil and worldwide.8,9 In addition to the use of jabuticaba as food and beverage, in folk medicine, that fruit is used to treat some diseases, such as asthma, inflammations, and gastrointestinal and cardiovascular disorders.10 Recent findings have shown that jabuticaba can decrease oxidative process,11 hyperglycemia associated with insulin resistance12 and dyslipidemia.13 In addition, that species has a proven endothelium-dependent hypotensive and vasodilating effect, mediated by nitric oxide pathway.14

Considering that jabuticaba has important biological effects and that its action on the cardiovascular system has been little studied, this study was aimed at assessing the possible effect of the jabuticaba extract directly on the VSM, mainly its effect on Ca2+ influx through the plasma membrane and activation of K+ channels.

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Methods

Preparation of jabuticaba extractFor this study, the plant specimens were donated by the

“Jabuticabal” wine house in the city of Hidrolândia, Goiás state, Brazil. A sample of the plant specimen was stored at the herbarium of the department of botany of the Federal University of Goiás (UFG), Goiânia, Goiás state, Brazil (n. 21140). Seedless fruits were dried in a greenhouse with air circulation, powdered in a pulverizer mill and passed through a 60-mesh sieve at the Laboratory of Research on Natural Products, Pharmacy School/UFG. The powder obtained was stored at -20°C. To prepare the extract, the dried material was exhaustively percolated into an ethanol:water solution (55:45 v/v), and the material obtained was filtered and submitted to rotary evaporation under reduced pressure at 40°C, resulting in the ethanol-free jabuticaba hydroalcoholic extract (JHE). After that process, the JHE was maintained in a freezer (-20°C) protected from light. On the days of experiment, the JHE was solubilized in distilled water at the concentration of 120 mg/mL.

The phytochemical characterization and pattern of the JHE showed 17.89% of phenolic compounds, quantified by using the Hagerman and Butler method, adapted by Mole and Watermen.15 The JHE showed ellagic acid (phytochemical marker, determined by HPLC-PDA) at 0.222% concentration.14 According to Abe et at.,9 the total ellagic acid content in M. cauliflora fruits ranges from 0.021% to 0.311%. Thus, that phytochemical marker concentration in JHE is in accordance with the fruit content.

Animals and preparation of isolated arteriesWistar male rats (200-230 g) from the central vivarium of

the UFG were used in this study. All experimental protocols abided by the UFG Animal Research Ethics Committee (protocol: 015/2014). This study is in accordance with the European Union Guide to the Care and Use of Experimental Animals (2010/63/UE).

The rats were sacrificed by use of cervical dislocation under inhalation anesthesia. Thoracic aorta was isolated, cleared of connective and adipose tissues, and sliced into rings (± 4 mm), which were mounted between two metal hooks, one of which was connected to a power transducer to record isometric tension (DATAQ Instruments, Akron, OH, USA) and the other was fixed to a cube for the isolated organ. The rings were placed into chambers for isolated organs, containing modified Krebs solution [composition in mM: NaCl, 130.0; KCl, 4.7; KH2PO4, 1.2; CaCl2,1.6; MgSO4, 1.2; NaHCO3, 14.9; glucose, 5.5], at pH of 7.4, under gasification with carbogen mixture (95% O2 + 5% CO2) at 37°C, and maintained at baseline tension of 1 g (ideal resting tension, previously standardized at our laboratory). To prevent the influence of vascular-endothelium-derived factors, endothelial cells were mechanically removed by rubbing the vessel lumen with a thin metal rod, the effectiveness of the removal being evidenced by lack of relaxation due to acetylcholine (1 µM) in aortic rings pre-contracted with EC50 of phenylephrine (0.1 µM).

Experimental protocolsAfter 60 minutes of stabilization at baseline tension (1 g),

the arteries were pre-contracted with phenylephrine (0.1 µM), and cumulative relaxation-concentration-effect curves were built for JHE (0 to 1.92 mg/mL) and for verapamil, used as inner control (10 nM to 100 µM).

To assess the cellular pathways responsible for the relaxant effect of JHE, aortic rings were pre-contracted with phenylephrine (0.1 µM) for 20 minutes after incubation with the following agents: 1) Ca2+ ATPase of the sarcoplasmic reticulum, cyclopiazonic acid (CPA, 10 µM); 2) non-selective K+ channel blocker, tetraethyl-ammonium (TEA, 1 mM); 3) selective voltage-gated K+ channel (Kv) blocker, 4-aminopyridine (4-AP, 1 mM); 4) selective ATP-sensitive K+ channel (KATP) blocker, glibenclamide (3 µM); 5) Ca2+-dependent K+ channel (KCa) blocker, clotrimazole (5 µM).

To assess the influence of JHE on the contraction induced by adrenergic contractile agonist, concentration-effect curves were built for phenylephrine (selective α1-adrenergic agonist, 0.1 nM to 10 µM) in the presence (20 minutes) or absence of JHE at inhibitory concentration 50% (IC50, 0.5 mg/mL) or 100% (IC100, 1.92 mg/mL). In addition, the inhibitory effect of the Ca2+ channel blocker verapamil (IC50, 0.3 µM) was assessed as inner control.

In another series of experiments, JHE action on Ca2+

influx stimulated by two different agents was analyzed. The preparations were initially contracted with a KCl solution (75 mM) to cause maximum contraction of each preparation (100% contraction), being then rinsed with Ca2+-free Krebs solution until total relaxation. To exhaust the intracellular storage of Ca2+, the preparations were stimulated to contract with phenylephrine in Ca2+-free Krebs solution until any contractile response disappeared (approximately 5 or 6 times, for 30-50 minutes). Then the preparations were rinsed several times with Ca2+-free Krebs solution, and then incubated for 20 minutes with JHE at inhibitory concentration 50% (IC50, 0.51 mg/mL) or 100% (IC100, 1.92 mg/mL). In addition, the inhibitory effect of the Ca2+ channel blocker verapamil (IC50, 0.3 µM) was assessed as inner control. After incubation, the contractile stimulus was applied (phenylephrine, 0.1 µM, or KCL, 75 mM), and concentration-effect curves were built for CaCl2 (0 to 3.0 mM).

Statistical analysisThe results of isometric tension were expressed as

mean ± standard error of the mean (SEM) of at least five experiments (n = 5-8) obtained from different animals. The graphs were built and analyzed by use of the GraphPad Prism software (GraphPad Software Corporation, 5.0 version) with ANOVA and Bonferroni post-test. The 5% significance level (p < 0.05) was adopted for the differences.

Results

Relaxant effect of JHE on isolated arteriesThe JHE caused relaxation in preparations of endothelium-

denuded arteries on a concentration-dependent way,

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Figure 1 – Cumulative concentration-response curves of jabuticaba hydroalcoholic extract (JHE) (A) and verapamil (B) in isolated endothelium-denuded arteries. The points represent mean ± SEM of the relaxant effect expressed as % relaxation.

relaxation initiating at the concentration of 0.38 mg/mL, and achieving the maximum effect (Emax) of 98.3% ± 0.4% (n = 6) at the concentration of 1.92 mg/mL (IC100) (Figure 1A). The JHE concentration that induced 50% relaxation (IC50) was 0.51 mg/mL. Similarly, verapamil (used as positive control) induced concentration-dependent relaxation with Emax of 99.8% ± 1.8% (n = 5) and IC50 of 0.3 µM.

Effect of JHE on the phenylephrine-induced contractionThe Emax value for phenylephrine (142.1% ± 7.1%, n = 6)

was significantly (p < 0.001) reduced to 88.7% ± 6.2% (n = 5), 66.1% ± 5.1% (n = 6) and 79.9% ± 5.5% (n = 5) after incubation with IC50 and IC100 of JHE or verapamil, respectively. The addition of IC50 and IC100 of JHE or verapamil significantly increased phenylephrine pD2 values (-log EC50) from 6.24 ± 0.09 to 5.35 ± 0.04, 5.14 ± 0.09 and 5.68 ± 0.07, respectively (Figure 2).

Effect of JHE on Ca2+-influx-induced contraction in preparations stimulated with phenylephrine or KCl

Regarding the Ca2+-influx-induced contraction stimulated by phenylephrine, pre-incubation with JHE (IC50 or IC100) significantly reduced (p < 0.001) the Emax values from 106.8% ± 7.5% (n = 5) to 58.8% ± 4.9% (n = 6) and 34.5% ± 3.2% (n = 6), respectively. In addition, treatment

with verapamil significantly reduced (p < 0.001) the contraction to 7.1% ± 1.1% (n = 5) (Figure 3A).

Regarding the Ca2+-influx-induced contraction stimulated by KCl (75 mM), pre-incubation with JHE (IC50 or IC100) significantly reduced (p < 0.001) the Emax values from 108.8% ± 4.3% (n = 5) to 63.8% ± 6.1% (n = 6) and 14.6% ± 1.9% (n=6), respectively. In addition, treatment with verapamil significantly reduced (p < 0.001) the contraction to 15.5% ± 1.1% (n=6) (Figure 3B).

Effect of reticular Ca2+ ATPase inhibitor, CPA, and K+-channel blockers on JHE- induced relaxation

Treatment with CPA did not change the JHE-induced relaxation (93.8% ± 4.6%, n = 6) in isolated arteries (Figure 4). Thus, JHE did not change the inner Ca2+ uptake by the sarcoplasmic reticulum to induce vascular relaxation.

As shown in f igure 5, except for clotr imazole (94.1% ± 4.5%, n = 5), K+-channel blockers changed the JHE-stimulated relaxation. The JHE-induced relaxation (Emax: 98.3% ± 0.4%, n = 6) was significantly (p < 0.05) reduced by TEA (Emax: 87.6% ± 5.7%, n=5), glibenclamide (Emax: 61.6% ± 5.8%, n = 6) and 4-AP (Emax: 81.6% ± 5.9%, n = 5). The results showed that JHE-induced relaxation depends on K+ efflux through the membrane.

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Figure 2 – Effect of jabuticaba hydroalcoholic extract (JHE) and verapamil on the phenylephrine-induced contraction in isolated endothelium-denuded arteries. Cumulative concentration-response curves were built in control conditions and after incubation (20 min) with JHE (IC50: 0.51 or IC100: 1.92 mg/mL) or verapamil (IC50: 0.3 µM). The points represent mean ± SEM of the contractile effect expressed as % contraction in relation to total KCl-induced contraction (75 mM). Significant difference: *** p<0.001 vs. Control.

DiscussionThe major finding of this study is that JHE, in addition to

having a hypotensive effect and inducing vascular relaxation through endothelial nitric oxide pathway, as shown by our team,14 acts directly on VSM and leads to endothelium-independent relaxation. Therefore, jabuticaba clearly has

Figure 3 – Effect of jabuticaba hydroalcoholic extract (JHE) and verapamil on the contractile response in isolated endothelium-denuded arteries. Cumulative concentration-response curves for CaCl2 were stimulated with phenylephrine (0.1 µM) (A) or KCl 75 mM (B) in control conditions and after incubation (20 min) with JHE (IC50: 0.51 or IC100: 1.92 mg/mL) or verapamil (IC50: 0.3 µM). The points represent mean ± SEM of the contractile effect expressed as % contraction in relation to total KCl-induced contraction (75 mM). Significant difference: *** p<0.001 vs. Control.

cardiovascular effects through multiple endothelium-dependent and independent pathways. It is worth noting that the JHE concentration capable of inducing 100% vascular relaxation through the endothelial pathway is approximately 16 times lower (0.12 mg/mL)14 than the JHE concentration necessary to induce 100% relaxation acting directly on VSM (1.92 mg/mL).

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Figure 4 – Maximum relaxant effect induced by jabuticaba hydroalcoholic extract (JHE) in isolated arteries pre-contracted with phenylephrine (0.1 µM) in the absence or presence (20 min) of the reticular Ca2+ ATPase inhibitor, cyclopiazonic acid (CPA, 10 µM). The bars represent mean ± SEM of the maximum relaxant effect expressed as % relaxation.

Figure 5 – Effects of K+ channel blockers on the relaxation induced by jabuticaba hydroalcoholic extract (JHE) in isolated arteries pre-contracted with phenylephrine (0.1 µM) in the absence or presence (20 min) of the blockers tetraethyl-ammonium (TEA, 1 mM), glibenclamide (Glib, 3 µM), clotrimazole (5 µM) and 4-aminopyridine (4-AP, 1 mM). The points represent mean ± SEM of the relaxant effect expressed as % relaxation. Significant difference: *p < 0.05; *** p < 0.001 vs. Control

Blood vessel contraction and relaxation in response to physiological demands are controlled by changes in intracellular Ca2+ concentration of VSM. The Ca2+ used for contraction includes intracellular or extracellular sources, or both. Sarcoplasmic reticulum is the major source of intracellular Ca2+.16 Our experiments showed that JHE does not change Ca2+ uptake by the sarcoplasmic reticulum, because its selective inhibitor, CPA, did not change the relaxation profile.

Voltage-gated Ca2+ channels (VGCC), also known as L-type Ca2+ channels, and receptor-operated Ca2+ channels (ROCC) located on the plasma membrane of VSM cells play a fundamental role in controlling Ca2+ influx.17,18 Phenylephrine-induced contraction is mediated by Ca2+ influx increase via VGCC and ROCC.19,20 However, contraction induced by membrane depolarization, such as in high KCl

concentrations, activates preferentially VGCC.21 The results of the present study show that treating arteries with JHE inhibits the vascular contraction induced by the adrenergic stimulus with phenylephrine, suggesting that JHE blocks Ca2+ influx by interfering with VGCC and/or ROCC.

In an attempt to clarify the cell mechanism through which JHE induces vascular relaxation, experiments were performed in a Ca2+-free solution. Two different stimuli, phenylephrine and KCl (75 mM), were used to induce Ca2+ influx. The JHE, as well as verapamil, used as a positive control, inhibited the Ca2+-influx-induced contraction mediated by both stimuli. Because membrane depolarization with high concentrations of K+ activates specifically VGCC, we suggest that JHE acts directly or indirectly by blocking Ca2+ influx through the plasma membrane, acting preferentially on VGCC.

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Natural products have constantly shown the involvement of K+ channels in their vasodilating mechanism.22 Several types of K+ channels, such as ATP-sensitive K+ channels (KATP), Ca2+-dependent K+ channels (Kca) and voltage-gated K+ channels (Kv), are present in VSM.23,24 Those channels can be blocked by glibenclamide, clotrimazole and 4-AP, respectively.24,25 Tetraethyl-ammonium is a non-selective blocker of those channels. When activated, those channels allow K+ efflux, hyperpolarizing the VSM plasma membrane. This reduces Ca2+ influx through the VGCC and induces vasodilation.26,27 The present study shows that JHE-induced relaxation in endothelium-denuded arteries is hindered after K+ channel blockade. Except for clotrimazole, the other blockers hindered vascular relaxation, allowing relating its activation to the JHE effect.

Our results point to a new biological effect of jabuticaba, a Brazilian native specimen that has important biological effects on the cardiovascular system, such as glucose-lowering ,12 lipid-lowering13 and hypotensive effects.14 Thus, the biological jabuticaba-induced effects demonstrated in this study will contribute to increase the knowledge about jabuticaba-derived compounds and their use as medicinal plant or functional food to prevent cardiovascular problems.

ConclusionThis study shows that JHE induces endothelium-

independent vasodilation. The major cellular pathways used by JHE to cause vascular relaxation are inhibition of the Ca2+-influx through plasma membrane, in addition to K+ channel activation in VSM cells.

AcknowledgementsThis research was funded by the Goiás State Research

Support Foundation (FAPEG), process 201310267000013. The Brazilian National Council for Scientific and Technological Development (CNPq) provided funding to support the Master’s program of Daniela L. M. de Andrade.

Author contributionsConception and design of the research: Andrade DML,

Borges LL, Torres IMS, Conceição EC, Rocha ML; Acquisition of data: Andrade DML, Borges LL, Conceição EC, Rocha ML; Analysis and interpretation of the data: Andrade DML, Torres IMS, Conceição EC, Rocha ML; Statistical analysis: Andrade DML, Rocha ML; Obtaining financing: Rocha ML; Writing of the manuscript: Andrade DML, Torres IMS, Rocha ML; Critical revision of the manuscript for intellectual content: Andrade DML, Borges LL, Conceição EC, Rocha ML.


was reported.

Sources of FundingThis study was partially funded by FAPEG/GO.

Study AssociationThis article is part of the thesis of master submitted by

Daniela Medeiros Lobo Andrade, from Faculdade de Farmácia - Universidade Federal de Goiás.

1. Lim SS, Vos T, Flaxman AD, Danaei G, Shibuya K, Adair-Rohani H, et al. A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the global burden of disease study 2010. Lancet. 2012;380(9859):2224-60. Erratum in: Lancet. 2013;381(9867):628, Lancet. 2013;381(9874):1276.

2. Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, He J. Global burden of hypertension: analysis of worldwide data. Lancet. 2005;365(9455):217-23.

3. Carafoli E. Intracellular calcium homeostasis. Annu Rev Biochem. 1987;56:395-433.

4. Somlyo AV, Bond M, Somlyo AP, Scarpa A. Inositol trisphosphate-induced calcium release and contraction in vascular smooth muscle. Proc Natl Acad Sci USA. 1985;82(15):5231-5.

5. Baker EH. Ion channels and the control of blood pressure. Br J Clin Pharmacol. 2000;49(3):185-98.

6. Greenway F, Liu Z, Yu Y, Gupta A. A clinical trial testing the safety and efficacy of a Standardized Eucommia ulmoides oliver bark extract to treat hypertension. Altern Med Rev. 2011;16(4):338-47.

7. Chan P, Tomlinson B, Chen YJ, Liu JC, Hsieh MH, Cheng JT. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Br J Clin Pharmacol. 2000;50(3):215-20.

8. Fortes GA, Naves SS, Godoi FF, Duarte AR, Ferri PH, Santos SC. Assessment of a maturity index in jabuticaba fruit by the evaluation of phenolic compounds, essential oil components, sugar content and total acidity. Am J Food Technol. 2011;6(11):974-84.

9. Abe LT, Lajolo FM, Genovese MI. Potential dietary sources of ellagic acid and other antioxidants among fruits consumed in Brazil: jabuticaba (Myrciaria jaboticaba (Vell.) Berg). J Sci Food Agric. 2012;92(8):1679-87.

10. Giraldi M, Hanazaki N. Use and traditional knowledge of medicinal plants at Sertão do Ribeirão, Florianopolis, Santa Catarina State, Brazil. Acta Bot Bras. 2010;24(2):395-406.

11. Reynertson KA, Yang H, Jiang B, Basile MJ, Kennelly EJ. Quantitative analysis of antiradical phenolic constituents from fourteen edible Myrtaceae fruits. Food Chem. 2008;109(4):883-908.

12. Dragano NR, Marques AY, Cintra DE, Solon C, Morari J, Leite-Legatti AV, et al. Freeze-dried jaboticaba peel powder improves insulin sensitivity in high-fat-fed mice. Br J Nutr. 2013;110(3):447-55.

13. Araújo CR, Esteves EA, Dessimoni-Pinto NA, Batista AG. Myrciaria cauliflora peel flour had a hypolipidemic effect in rats fed a moderately high-fat diet. J Med Food. 2014;17(2):262-7.

14. Lobo de Andrade DM, Reis CF, Castro PF, Borges LL, Amaral NO, Torres IM, et al. Vasorelaxant and Hypotensive Effects of Jaboticaba Fruit (Myrciaria cauliflora) Extract in Rats. Evid Based Complement Alternat Med. 2015;2015:696135.

References

228

Original Article


Arq Bras Cardiol. 2016; 107(3):223-229

15. Mole S, Waterman PG. A critical analysis of techniques for measuring tannins in ecological studies-II. Techniques for biochemically defining tannins. Oecologia. 1987;72(1):148-56.

16. Thomas AP, Bird GS, Hajoczky G, Robb-Gaspers LD, Putney JW Jr. Spatial and temporal aspects of cellular calcium signaling. FASEB J. 1996;10(13):1505-17.

17. Berridge MJ. Cell signall ing: a tale of two messengers. Nature. 1993;365(6445):388-9.

18. Hess P. Calcium channels in vertebrate cells. Annu Rev Neurosci. 1990;13:337-56.

19. Wesselman JP, VanBavel E, Pfaffendorf M, Spaan JA. Voltage-operated calcium channels are essential for the myogenic responsiveness of cannulated rat mesenteric small arteries. J Vasc Res. 1996;33:32-41.

20. Lee CH, Poburko D, Sahota P, Sandhu J, Ruehlmann DO, van Breemen C. The mechanism of phenylephrine-mediated [Ca(2+)](i) oscillations underlying tonic contraction in the rabbit inferior vena cava. J Physiol. 2001;534(Pt 3):641-50.

21. Kochegarov AA. Pharmacological modulators of voltage-gated calcium channels and their therapeutic application. Cell Calcium. 2003;33(3):145-62.

22. McNeill JR, Jurgens TM. A systematic review of mechanisms by which natural products of plant origin evoke vasodilatation. Can J Physiol Pharmacol. 2006;84(8-9):803-21.

23. Ko EA, Han J, Jung ID, Park WS. Physiological roles of K+ channels in vascular smooth muscle cells. J Smooth Muscle Res. 2008:44(2):65-81.

24. Ferrer M, Marin J, Encabo A, Alonso MJ, Balfagon G. Role of K+ channels and sodium pump in the vasodilation induced by acetylcholine, nitric oxide, and cyclic GMP in the rabbit aorta. Gen Pharmacol. 1999;33(1):35-41.

25. Wulff H, Miller MJ, Hansel W, Grissmer S, Cahalan MD, Chandy KG. Design of a potent and selective inhibitor of the intermediate-conductance Ca2+-activated K+ channel, IKCa1: a potential immunosuppressant. Proc Natl Acad Sci USA. 2000;97(14):8151-6.

26. Nelson MT, Quayle JM. Physiological roles and properties of potassium channels in arterial smooth muscle. Am J Physiol. 1995;268(4 Pt 1):C799-822.

27. Ledoux J, Werner ME, Brayden JE, Nelson MT. Calcium activated potassium channels and the regulation of vascular tone. Physiology (Bethesda). 2006;21:69-78.

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Proportional Mortality due to Heart Failure and Ischemic Heart Diseases in the Brazilian Regions from 2004 to 2011Eduardo Nagib Gaui1, Carlos Henrique Klein2, Glaucia Maria Moraes de Oliveira1

Programa de Pós Graduação em Cardiologia - Universidade Federal do Rio de Janeiro1; Escola Nacional de Saúde Pública - Fiocruz2, Rio de Janeiro, RJ – Brazil

Mailing Address: Gláucia Maria Moraes de Oliveira •Universidade Federal do Rio de Janeiro. João Lira 128, 101, Postal Code 22430-210, Leblon, Rio de Janeiro, RJ – Brazil.E-mail: [email protected], [email protected] received January 20, 2016; revised manuscript May 13, 2016; accepted May 16, 2016.

DOI: 10.5935/abc.20160119

AbstractBackground: Heart failure (HF) and ischemic heart diseases (IHD) are important causes of death in Brazil.Objective: To assess proportional mortality (PM) due to HF and IHD as underlying causes stratified by sex and age groups in the Brazilian geoeconomic regions from 2004 to 2011.Methods: Data from death certificates were obtained in the DATASUS site under the following International Statistical Classification of Diseases and Related Health Problems codes, 10th Revision: 1) from chapter IX: I20 to I24 for acute IHD, I25 for chronic IHD, and I50 for HF; and 2) from chapter XVIII, for ill-defined causes (IDC).Results: Proportional mortality due to HF increased with age in both sexes and all regions, the highest percentages being found among elderly women. Among men, the highest percentages were observed in the West-Central region up to the ninth decade, but, among the eldest individuals, the highest percentages were identified in the Southern region. Among women, the regions did not differ up to the age group of 70-79 years, although the West-Central region took the lead from 50 to 79 years; however, from the age of 80 years on, the Southern region showed the highest PM due to HF. Proportional mortality due to acute IHD in all Brazilian regions and in both sexes increased up to the age group of 60-69 years, from which it decreased. Among men, the Southeastern region had the highest percentages in the age group of 50-59 years, while women had lower PM due to acute IHD than men in all regions. In both sexes, PM due to chronic IHD increased with age in the Southern and Southeastern regions, which did not happen in the others, while the Southern region had the highest rate of all regions for all age groups.Conclusions: Regional differences were more prominent at more advanced ages, especially when deaths due to IDC were excluded. (Arq Bras Cardiol. 2016; 107(3):230-238)Keywords: Heart failure/mortality; Myocardial Ischemia/mortaity; Death Certificates; Epidemiology; Brazil

IntroductionDiseases of the circulatory system (DCS) are important

causes of death in Brazil. The World Health Organization provides a classification of diseases, the International Statistical Classification of Diseases and Related Health Problems (ICD),1 whose purpose is to permit the systematic recording analysis, interpretation and comparison of mortality and morbidity data.

In the death certificate model used in Brazil, the 49th field is intended to record the causes of death. This field is divided into two parts. Part I has four rows (a, b, c, and d), where all diseases or injuries that contributed to or produced death, or the circumstances of the accident or violence that produced these injuries must be registered. Line a should be used to the immediate cause. Lines b, c, and d should be used to the causes that led to the immediate cause (line a), line d being reserved for the underlying cause of death. In Part II

any significant morbid condition that could have influenced unfavorably the evolution of the disease process is recorded, thereby contributing to the patient’s death, without, however, relating to the disease or medical condition that directly caused the death. These causes are called contributing causes. It should be noted that even if there is a line for stating the underlying cause of death, the selection of that cause is defined by specific rules set in the 10th Revision of ICD (ICD-10).

Chapter IX of ICD-10 provides the alphanumeric codes to classify DCS, which were identified as the underlying cause of death in 335,177 of the 1,169,966 death certificates issued in 2011 in Brazil, corresponding to 29% of the total deaths in that year.2

Of the DCS, the following stand out: heart failure (HF) and acute and chronic ischemic heart diseases (IHD). A large number of survivors of acute IHD episodes progress to HF, which is the final stage of several heart diseases.3,4

Heart failure accounts for high morbidity and mortality, and its prevalence tends to increase with both population aging and the increased survival of patients experiencing acute coronaryevents.5 In Brazil, HF has been reported as an important cause of hospitalization, mainly after the age of 60 years.6

Ischemic heart diseases accounted for 31% of the deaths due to DCS in Brazil in 2011,2 and remain as the major cause

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of death in adults in Latin America.7 In Brazil, mortality rates due to IHD, standardized according to age, showed a mild declining trend from 1996 to 2011.8

This study aimed at assessing proportional mortalities due to HF and IHD, selected as underlying causes of death, stratified by sex and age, in the Brazilian geoeconomic regions from 2004 to 2011.

MethodsData from death registries, comprising death certificates, of

the Brazilian states from 2004 to 2011 were obtained in the Brazilian Health System database (DATASUS)2. The number of death certificates from each of the five Brazilian geoeconomic regions (Northern, Northeastern, West-Central, Southeastern and Southern) was calculated by adding the number of death certificates of the states forming each Brazilian region. The study period (from 2004 to 2011) was chosen based on the following: it has been only since 2004 that all causes of death notified by certifiers using all lines of the document [parts I (from a to d) and II] have been recorded in all Brazilian states; 2011 was the last year available at the time of data collection for this study.

The electronic death registries used the mortality classification of ICD-10, from which the following codes were selected: 1) from chapter IX: I20 to I24 for acute IHD; I25 for chronic IHD; and I50 for HF; and 2) from chapter XVIII, the codes for ill-defined causes (IDC).1 The age groups (in years) studied were as follows: 0-39; 40-49; 50-59; 60-69; 70-79; 80-89; and 90 or older.

Proportional mortality is a measure of the importance of a specific cause of death in relation to all causes of death within the same population group. This study assessed proportional mortalities due to HF, acute IHD, chronic IHD, and IDC selected as underlying causes of death, stratified by sex and age, in the Brazilian geoeconomic regions (Tables 1 and 2).

The graphs of Figure 1 show the proportional mortalities due to HF and acute and chronic IHD, except for the deaths whose causes were encoded as ill-defined, stratified by sex and age groups in the Brazilian geoeconomic regions. Thus, the calculation of the proportional mortalities shown in Figure 1 considered only deaths due to defined causes in their denominators.

Stata statistical software, version 12, was used to calculate the percentages and to elaborate the graphs (Stata Corporation, College Station, Texas, USA).9

ResultsIn Brazil, 8,597,955 deaths were registered from 2004 to

2011. The ICD-10 codes of the underlying causes of death retrieved from death certificates were as follows: HF, 2.6%; acute IHD, 7.3%; and chronic IHD, 1.4%. In that period, 8.3% of the death certificates had IDC as the underlying cause of death.

The distribution of proportional mortalities due to HF in the Brazilian regions was as follows, the highest figures found in the Southern region, and the lowest, in the Northern

region: Southern region, 2.9%; West-Central, 2.8%; Northeastern and Southeastern, 2.5% each; and Northern region, 2.2%. Deaths due to acute IHD were proportionally more frequent in the Southern and Southeastern regions (7.7% and 7.6%, respectively), followed by the Northeastern, West-Central and Northern regions (7.0%, 6.8% and 5.2%, respectively). Regarding chronic IHD, the distribution of proportional mortalities was as follows: Southern, 2.1%; Southeastern, 1.7%; West-Central, 1.4%; Northeastern, 0.8%; and Northern, 0.4%.

Regarding IDC, the distribution of proportional mortality according to the Brazilian regions was as follows, with the highest figures observed in the Northern region: Northern, 14.1%; Northeastern, 11.0%; Southeastern, 7.7%; Southern, 5.3%; and West-Central, 4.5%.

Table 1 shows the proportional mortality due to HF, acute or chronic IHD, and IDC as underlying causes of death in the Brazilian regions according to the age group in men from 2004 to 2011. Table 2 shows the same for women.

The proportional mortality due to HF increased with age increase in all Brazilian regions in both sexes (Tables 1 and 2), although such increase was not observed in men aged 90 years or older in the Northern region. In the male sex, the highest percentages were observed in the West-Central region up to the age group of 80-89 years, but, among the eldest individuals, the highest percentages were observed in the Southern region. However, the Southern region had the lowest proportional mortalities up to the age group of 60-69 years. From that age onward, while the Southeastern region continued to show the lowest proportional mortalities up to the age group of 80-89 years, the Southern region stood up with the most notable increase of all regions in the male sex (Table 1). In the female sex, no significant difference was identified among the regions up to the age group of 70-79 years, although the West-Central region took the lead from 50 years to 79 years; however, from the age of 80 years on, the Southern region showed the highest proportional mortalities due to HF (Table 2).

The proportional mortality due to acute IHD in all Brazilian regions and in both sexes increased up to the age group of 60-69 years, from which it decreased (Tables 1 and 2). But women still had lower proportional mortality due to acute IHD than men did in all regions. However, for both sexes, the differences between regions in almost all age groups were not significant, except for the Northern region, which always had the lowest proportional mortalities (Tables 1 and 2).

The proportional mortalities due to chronic IHD were lower than those due to the other selected causes (Tables 1 and 2). For both sexes, mortality increased with age in the Southern and Southeastern regions, but not in the other regions. The proportional mortality due to chronic IHD in the Southern region was higher than in the other regions for all age groups in the female sex (Table 2); in the male sex, however, this was observed only for the age of 50 years and older (Table 1). That was followed in decreasing order and for both sexes by the regions: Southeastern, West-Central, Northeastern and Northern (Tables 1 and 2).

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Table 1 - Proportional mortality (%) due to heart failure, acute or chronic ischemic heart diseases and ill-defined causes as underlying causes of death in the Brazilian geoeconomic regions stratified by age group in the male sex from 2004 to 2011

Cause Region

Age group Northen Northestern West-Central Southeastern Southern Brazil

HF0-39 0.4 0.4 0.5 0.3 0.2 0.4

40-49 1.3 1.2 1.4 1.0 0.9 1.1

50-59 1.9 1.9 2.4 1.5 1.4 1.6

60-69 3.0 2.6 3.2 2.2 2.1 2.4

70-79 3.5 3.3 3.7 2.9 3.1 3.1

80-89 4.4 4.1 4.7 3.7 4.5 4.0

90ou+ 4.1 4.9 4.9 4.4 5.9 4.8

Total 2.1 2.3 2.5 2.1 2.2 2.2

Acute IHD

0-39 0.8 1.1 1.1 1.3 1.1 1.2

40-49 5.8 6.6 7.0 7.4 7.1 7.0

50-59 9.2 10.3 11.2 11 10.7 10.7

60-69 9.5 11.5 11.3 11.5 11.3 11.3

70-79 8.7 9.9 9.7 9.8 9.8 9.8

80-89 6.5 7.7 7.0 7.8 7.6 7.6

90ou+ 5.2 6.2 5.1 5.6 5.8 5.8

Total 5.4 6.9 7.1 8.0 7.9 7.5

Chronic IHD

0-39 0.0 0.1 0.1 0.1 0.1 0.1

40-49 0.3 0.4 0.9 0.9 1.0 0.8

50-59 0.5 0.9 1.7 1.7 1.9 1.5

60-69 0.7 1.2 2.1 2.2 2.5 2.0

70-79 0.8 1.2 2.0 2.3 2.8 2.1

80-89 0.7 1.1 1.8 2.3 2.9 2.0

90ou+ 0.6 0.9 1.8 2.3 2.6 1.7

Total 0.4 0.8 1.3 1.6 2.0 1.4

IDC

0-39 8.5 5.5 3.1 5.8 3.3 5.4

40-49 13.0 9.2 5.0 9.4 6.1 8.8

50-59 13.7 9.7 5.2 8.7 5.8 8.5

60-69 14.9 10.4 4.8 8.0 5.3 8.1

70-79 16.7 11.8 4.6 7.2 5.0 8.1

80-89 20.4 14.9 5.3 7.5 5.8 9.7

90ou+ 28.9 21.3 8.9 11.1 10.6 15.4

Total 13.6 10.4 4.6 7.7 5.3 8.2

N

0-39 105,308 343,734 86,283 433,740 141,069 1,110.134

40-49 28,015 115,165 34,803 232,483 74,713 485,179

50-59 33,372 141,644 43,708 339,116 111,350 669,190

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Continuation60-69 39,834 176,257 52,799 398,437 145,124 812,451

70-79 45,588 209,710 57,177 462,905 167,670 943,050

80-89 31,220 185,762 37,783 324,647 111,796 691,208

90ou+ 10,272 71,998 11,102 83,886 26,570 203,828

Total 293,609 1,244.270 323,655 2,275.214 778,292 4,915.040

ICD-10: International Statistical Classification of Diseasesand Related Health Problems - 10th revision.ICD-10: codes: from Chapter IX for HF - 150, for acute IHD - 120-124, and for chronic IHD - 125; and from Chapter XVIII for IDC.HF: heart failure; IHD: acute or chronic ischemic heart diseases; IDC: ill-defined causes.

Table 2 - Proportional mortality (%) due to heart failure, acute or chronic ischemic heart diseases and ill-defined causes as underlying causes of death in the Brazilian geoeconomic regions stratified by age group in the female sex from 2004 to 2011

Cause Region

Age group Northern Northeastern West-Central Southeastern Southern Brazil

HF

0-39 0.6 0.7 0.5 0.5 0.4 0.6

40-49 1.2 1.6 1.6 1.2 1.2 1.3

50-59 1.9 2.3 2.5 1.9 1.8 2.0

60-69 2.8 2.8 3.3 2.6 2.8 2.8

70-79 3.4 3.3 4.4 3.4 4.2 3.6

80-89 3.8 4.0 5.1 4.3 5.8 4.5

90 or + 4.3 4.6 5.8 4.9 7.4 5.2

Total 2.4 2.9 3.3 3.0 3.8 3.1

Acute IHD

0-39 0.7 1.1 1.0 1.2 1.0 1.1

40-49 4.7 7.1 6.0 6.3 6.3 6.4

50-59 6.8 9.2 7.8 8.2 8.2 8.4

60-69 7.7 10.1 9.1 9.4 9.4 9.5

70-79 7.1 9.2 8.2 9 9.2 9

80-89 6.0 7.5 6.6 7.3 7.6 7.3

90 or + 4.8 5.9 4.9 5.8 6 5.8

Total 4.9 7.2 6.3 7.3 7.5 7.1

Chronic IHD

0-39 0.0 0.1 0.1 0.1 0.1 0.1

40-49 0.2 0.5 1.0 0.8 0.9 0.7

50-59 0.4 0.8 1.4 1.4 1.6 1.2

60-69 0.6 1.0 1.8 1.9 2.2 1.7

70-79 0.8 1.2 1.8 2.1 2.7 1.9

80-89 0.7 1.1 1.8 2.2 3.0 2.0

90 or + 0.7 1.0 1.9 2.4 3.2 2.0

Total 0.5 0.9 1.4 1.7 2.2 1.5

IDC

0-39 9.8 7.3 3.4 6.1 3.7 6.3

40-49 11.3 8.9 4.3 7.4 4.5 7.3

50-59 11.8 8.8 3.6 7.0 4.4 7.0

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The proportional mortalities due to IDC increased progressively with age in the Northern and Northeastern regions for both sexes (Tables 1 and 2). In addition those two regions stood out because of very high percentages as compared with the others. The West-Central region had the lowest percentages of death for all age groups and both sexes. It is worth noting that the oldest individuals (90 years or older) had the highest proportional mortalities for both sexes and all regions (Tables 1 and 2).

The graphs of Figure 1 show the percentages of death due to HF, acute and chronic IHD as underlying causes in the Brazilian regions, stratified by age group and sex, from 2004 to 2011. The calculation of the proportional mortalities shown considered in their denominators only deaths due to defined causes; those due to IDC were excluded.

The proportional mortalities due to HF, excluding IDC, increased with age in both sexes and all regions, including among men of the Northern region aged 90 years or older, differently from that observed in Table 1. The differences of percentages between the regions, which are small in the younger age groups, increase with age for both sexes (Figure 1). The greatest increases in the percentages of death due to HF among men as age increased were observed in the Southern and Northeastern regions, in this order, while for women the same was observed only in the Southern region. The lowest increases in the percentages of death due to HF among women as age increased were observed in the Southeastern and Northeastern regions.

The Southeastern region showed the lowest percentages of death due to HF among men aged 70 years and older, while, among women, that was observed earlier, from the age of 60 onwards (Figure 1).

The proportional mortality due to acute IHD, considering only the defined causes, increased with age for both sexes up to the age group of 60-69 years, in which the highest percentages were observed in all regions, and from which they began to decrease (Figure 1). Among men, the highest percentages of death due to acute IHD were observed in the Southeastern region up to the age group of 50-59 years, from which the highest percentages were observed in the Northeastern region. The Northern region had the lowest proportional mortalities due to acute IHD in both sexes up to the age group of 70-79 years, and the West-Central region showed the lowest percentages in the two oldest age groups. Among women, the Northeastern region had the highest proportional mortalities due to acute IHD in almost all age groups, except for the youngest, and the highest percentage was observed in the age group of 60-69 years.

The proportional mortality due to chronic IHD, considering only defined causes of death, increased progressively with age in the Southern and Southeastern regions among women; however, among men, it stabilized from the age group of 70-79 years onwards, with a mild decrease in the oldest age group in the Southern region (Figure 1). The Northern and Northeastern regions had the lowest proportional mortalities due to chronic IHD from the age group of 40-49 years onwards. In those two regions, the highest percentages were observed in the age group of 70-79 years in both sexes.

DiscussionThis study assessed the proportional mortalities due to HF

and acute and chronic IHD as underlying causes of death in the Brazilian geoeconomic regions, stratified by sex and age. This analysis was performed for the purpose of comparison, including and excluding the occurrence of death due to IDC.

Continuation60-69 13.4 9.6 3.6 6.8 4.3 7.2

70-79 15.7 11.2 3.7 6.9 4.7 7.7

80-89 20.1 14.5 5.0 7.7 6.1 9.4

90 or + 29.8 21.7 9.5 11.2 11.0 14.8

Total 14.8 11.8 4.3 7.5 5.4 8.4

N

0-39 49,782 146,364 36,437 184,665 59,689 476,937

40-49 14,073 60,516 17,437 119,553 37,702 249,281

50-59 19,309 92,027 25,253 192,631 62,242 391,462

60-69 25,177 134,654 34,437 269,106 92,995 556,369

70-79 32,284 187,067 43,297 400,302 138,749 801,699

80-89 28,163 197,554 36,886 415,142 139,630 817,375

90ou+ 14,674 101,902 15,540 174,025 53,005 359,146

Total 183,462 920,084 209,287 1,755,424 584,012 3,652,269

ICD-10: International Statistical Classification of Diseases and Related Health Problems – 10th revision.ICD-10 codes: from Chapter IX for HF - I50, for acute IHD- I20-I24, and for chronic IHD - I25; and from Chapter XVIII for IDC. HF: heart failure; IHD: acute or chronic ischemic heart diseases; IDC: ill-defined causes.

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Figure 1 – Proportional mortality due to heart failure (HF), acute and chronic ischemic heart diseases (IHD) as underlying causes of death, excluding deaths of ill-defined causes (IDC), and due to IDC as underlying cause of death, in the Brazilian geoeconomic regions, stratified by age group and sex, from 2004 to 2011.HF: heart failure; IHD: ischemic heart disease; IDC: ill-defined causes; NO: Northern; NE: Northeastern; WC: West-Central; SE: Southeastern; SO: SouthernICD-10: International Statistical Classification of Diseases and Related Health Problems – 10th revision.ICD-10 codes: from Chapter IX for HF - I50, for acute IHD - I20-I24, and for chronic IHD - I25; and from Chapter XVIII for IDC.

% of death due to HF as underlying cause in the malesex stratified by age group in the Brazilian regions - 2004 to 2011

0-39

40-49

50-59

60-69

70-79

80-8990 ou +

N

NE

WC

SE

S

7

6

5

4

3

2

1

0

0 10 20 30 40 50 60 70 80 90 100age in years

% o

f d

eath

0

0

N

NE

WC

SE

S

% of death due to HF as underlying cause in the femalesex stratified by age group in the Brazilian regions - 2004 to 2011

8

7

6

5

4

3

2

1

10 20 30 40 50 60 70 80 90 100age in years

0-39

40-49

50-59

60-69

70-79

80-89

90 ou +

% o

f d

eath

N

NE

WC

SE

S

0

0

2

4

6

8

10

12

14

10 20 30 40 50 60 70 80 90 100age in years

% o

f d

eath

0-39

40-49

50-5960-69

70-79

80-8990 ou +

% of death due to acute IHD as underlying cause in the malesex stratified by age group in the Brazilian regions - 2004 to 2011

N

NE

WC

SE

S

% of death due to acute IHD as underlying cause in the femalesex stratified by age group in the Brazilian regions - 2004 to 2011

0

0 10 20 30 40 50 60 70 80 90 100age in years

12

10

8

6

4

2

0-39

40-49

50-59

60-6970-79

80-89

90 ou +

% o

f d

eath

0

0

3

2,5

2

1,5

1

0,5

10 20 30 40 50 60 70 80 90 100age in years

% o

f d

eath

% of death due to chronic IHD as underlying cause in the malesex stratified by age group in the Brazilian regions - 2004 to 2011

N

NE

WC

SE

S

0-39

40-49

50-59

60-69

70-7980-89

90 ou +

0

0

4

3,5

3

2,5

2

1,5

1

0,5

10 20 30 40 50 60 70 80 90 100age in years

% of death due to chronic IHD as underlying cause in the femalesex stratified by age group in the Brazilian regions - 2004 to 2011

N

NE

WC

SE

S

0-3940-49

50-5960-69

70-79 80-8990 ou +

% o

f d

eath

0

0

3

6

9

12

15

18

21

24

27

30

10 20 30 40 50 60 70 80 90 100age in years

N NE WC SE S

% of death due to IDC as underlying cause in the malesex stratified by age group in the Brazilian regions - 2004 to 2011

% o

f d

eath

0-39

40-49 50-5960-69

70-79

80-89

90 ou +

0

0

N NE WC SE S

10 20 30 40 50 60 70 80 90 100age in years

% of death due to IDC as underlying cause in the femalesex stratified by age group in the Brazilian regions - 2004 to 2011

3

6

9

12

15

18

21

24

27

30

% o

f d

eath

0-3940-49 50-59

60-69

70-79

80-89

90 ou +

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It is worth noting that although proportional mortality does not represent raw mortality directly, they have an intrinsic relationship, because both share the same numerator. The difference between them lies in the denominator, which, in proportional mortality, is the total number of deaths due to any cause, considering the ill-defined deaths or not, while, in raw mortality, the denominator is the total number of individuals exposed to the risk of death. Thus, proportional mortality indicates directly the relative importance of a determined cause of death in the total set of deaths. This indicator can be preferred to that of raw mortality when the extent and quality of the death registry is more reliable than the population count. The latter, the census, is performed only once every ten years, being thus useful for only a short period of time. Regarding this study, the census was performed only in one of the years studied (2010), and, for the remaining seven years, only interpolated (2004 to 2009) and extrapolated (2011) estimates were considered. The estimation methods used by the official Brazilian Institute of Geography and Statistics (IBGE) have undergone significant changes since 2007, making the flotation of population segments, according to age and sex, important, and their use, of concerning validity.

As expected, proportional mortality due to HF10 increased with age increase, the highest percentages observed among women. The regional differences were more prominent in the older age groups, and even more when death certificates with IDC as underlying causes of death were excluded. In the Northern region, which had the highest percentages of IDC, considering all death certificates, the proportional mortality due to HF increased 14% and 16% among men and women, respectively, when IDC were excluded. At more advanced ages, when the percentages due to IDC were higher, the differences were more significant, reaching up to 40% more proportional mortality due to HF in the Northern region, for both sexes and over the age of 90 years.

It is worth noting that this study assessed the proportional mortality due to HF only when that was selected as the underlying cause of death, which, as already known,10 underestimates HF as a cause of death. Heart failure is more prevalent in the elderly, competing, in the selection of the underlying cause of death, with other diseases also common in more-advanced age groups. In addition, the rules determined for that selection discourage the coder to select HF as the underlying cause of death.10-13

The highest proportional mortalities due to acute IHD were observed in the age group of 60-69 years in all regions and both sexes, from which a more or less abrupt decrease was observed depending on the region analyzed. Women had lower proportional mortalities due to acute IHD as compared with men in almost all regions and age groups, regardless of the exclusion of IDC. The only exception was the age group of 40-49 years in the Northeastern region.

In addition, when analyzing proportional mortality due to acute IHD, the percentage of deaths due to IDC can conceal differences between regions, sexes or age groups. In the age group of 60-69 years, when IHD has its highest percentages, the greatest increases in proportional mortality due to IHD after excluding IDC were observed among women in the Northeastern region (22%) and men in the Northern region (18%).

The differences in mortality rates due to IHD between Brazilian regions have long been known,14 as has the difficulty of interpreting mortality data in regions with a high rate of deaths attributed to IDC. A recent study analyzing the trend of mortality rates due to IHD in Brazil from 2000 to 2010 has evidenced outstanding regional differences, which, according to the authors, can be explained by differences in socioeconomic conditions and health care structures.15

This is more easily perceived when an improvement in socioeconomic indicators precedes the reduction in mortality due to DCS, and there is a strong correlation between the progression of those indicators and the drop in mortality.16

One measure of the quality of information on mortality is the percentage of causes of death selected as ill defined, comprised in chapter XVIII of the CID-10.1 In Brazil, in 2003, the underlying cause of 13.3% of the deaths was encoded as ill-defined, the highest percentages found in the Northern and Northeastern regions.17 The percentage found in this study was lower, with IDC selected as the underlying cause of death in 8.3% of all deaths. This seems to indicate an improvement in the quality of information of death certificates, because of the reduction in the percentage of deaths due to IDC. In fact, this study shows that, in Brazil, the proportional mortality due to IDC decreased progressively from 12.3%, in 2004, to 6.7%, in 2011.

It is worth noting that a recent study assessing the behavior over time of mortality due to IDC in Brazil and its regions, from 1996 to 2011, has reported a drop in the raw and standardized mortality rates due to IDC in all regions; in the Northern and Northeastern regions, which have the highest rates, that drop has been steeper since 2004, which can represent greater care with the accuracy of death registries. Once again, this study confirms that, from 2004 to 2011, proportional mortalities due to IDC decreased from 20.8% to 11.0% in the Northern region, and from 23.7% to 7.7% in the Northeastern region. The other regions have also shown a decline, although less prominent, because the initial rates were lower.

In a publication discussing the reality of HF in Latin America, the authors have concluded that the region is under the awful paradox of HF risk factors and HF epidemiology of developed countries, with an added high prevalence of systemic arterial hypertension, Chagas’ disease and rheumatic fever, together with a lower total expenditure on health per capita.18

Differences between the regions regarding proportional mortality due to chronic IHD showed no important change, mainly because it was lower as compared with those due to the other causes studied, HF and acute IHD.

The proportional mortality due to IDC increased with age in all regions. The Northern and Northeastern regions maintained the leading position, reaching elevated values at the age group of 90 years or older, corresponding to one of every three death certificates in men, and one of every four death certificates in women. This jeopardizes the analysis of mortality in those regions, especially in the elderly population (Tables 1 and 2). Even excluding deaths due to IDC, such as in the proportional mortalities shown in Figure 1, one cannot state that the proportional mortality due to HF and IHD remains constant among the IDC in all age groups and for both sexes. It seems

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reasonable to suppose that, among the oldest individuals, the proportion of deaths that could have been attributed to HF or chronic IHD, for example those classified as ill-defined due to lack of proper information, would be higher than that among younger individuals. If this hypothesis is confirmed, proportional mortalities due to HF, for example, should be higher than those shown in Figure 1, especially among the oldest individuals, and even more prominent in those regions with the highest percentage of death due to IDC.

Data on mortality lose quality in the presence of a considerable proportion of IDC of death. Although the percentage of mortality due to IDC in Brazil decreased in past years, indicating an improvement in the quality of statistics on mortality,8 figures as those observed in the Northern and Northeastern regions are still concerning, and can be related to access to medical care and its quality, in addition to the proper completion of death certificates.

One limitation of this study derives from choosing the death certificate as the subject of study, because it depends on the quality of the registration and accuracy of the diagnoses made by physicians. Conversely, that is the most comprehensive source of information on deaths, because the death certificate is legally required to provide a proper destination of the deceased. Another study limitation was the use of the underlying cause of death to assess mortality, which, under certain circumstances, such as HF, can underestimate its relative importance when multiple causes, which contemplate all the causes mentioned on the death certificate, are not considered. Thus, the simultaneous presence of acute IHD and HF in the same death certificate can lead to the selection of IHD as the underlying cause of death.19 Therefore, the contribution of the causes assessed in this study, HF and IHD, will have to be analyzed, considering the existence of multiple causes de death.

ConclusionFor now, considering the underlying causes of death,

proportional mortality due to HF increases as age does, and, in the elderly, the highest percentages are observed among women. Proportional mortality due to acute IHD is usually higher among men, and, for both sexes, the age group of 60-69 years shows the highest values. Despite regional differences in proportional mortality due to acute IHD, it predominated among men in the age group of 40-49 years in the Southeastern region and in older age groups in the Northeastern region. Among women, proportional mortality due to acute IHD predominated from the fifth decade of life onwards in the Northeastern region.

Author contributionsConception and design of the research, Acquisition of

data, Analysis and interpretation of the data, Statistical analysis, Writing of the manuscript e Critical revision of the manuscript for intellectual content: Gaui EN, Klein CH, Oliveira GMM.

Potential Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Sources of Funding

There were no external funding sources for this study.

Study Association


1. Organização Mundial da Saúde(OMS). Classificação estatística internacional de doenças e problemas relacionados à saúde. 10ª rev. São Paulo: Edusp; 1997.

2. Ministerio da Saúde. Datasus. [Acesso em 2014 abr 10]. Disponível em: www2.datasus.gov.br/DATASUS/index.php?area=0205 acesso 23/03/2014

3. Senni M, Tribouilloy CM, Rodeheffer RJ, Jacobsen SJ, Evans JM, Bailey KR, et al. Congestive heart failure in the community: trends in incidence and survival in a 10-year period. Arch Intern Med.1999;159(1):29–34.

4. Mangini S, Silveira FS, Silva CP, Grativvol PS, Seguro LF, Ferreira SM, et al.Decompensated heart failure in the emergency department of a cardiology hospital.. Arq Bras Cardiol. 2008;90(6):400-6.

5. Gottdiener JS, Arnold AM, Aurigemma GP, Polak JF, Tracy RP, Kitzman DW, et al. Predictors of congestive heart failure in the elderly: the Cardiovascular Health Study. J Am Coll Cardiol. 2000;35(6):1628–37.

6. Albanesi Filho FM. What is the current scenario for hear failure in Brazil? Arq Bras Cardiol. 2005; 85(3):155-6.

7. Barcelo A. Cardiovascular diseases in Latin America and the Caribbean.Lancet 2006;368(9536):625–6.

8. Gaui EN, Oliveira GMM, Klein CH. Mortality by heart failure and ischemic heart disease in Brazil from 1996 to 2011. Arq Bras Cardiol. 2014;102(6):557-65.

9. Stata Corp: Statistics/Data Analysis Program, version 12.1-MP. College Station, Texas,USA; 2011.

10. Gaui EN, Klein CH, Oliveira GM. Mortality due to heart failure: extendedanalysis ad temporal trend in three states of Brazil. Arq Bras Cardiol. 2010; 94(1): 55-61.

11. Goldacre MJ, Mant D, Duncan M, Griffith M. Mortality from heart failure in an English population, 1979-2003: study of morte certification. J Epidemiol Community Health. 2005;59(9):782-84.

12. Engelfriet PM, Hoogenveen RT, Boshuizen HC, van Baal PH. To die with or from heart failure: a difference that counts. Eur J Heart Fail. 2011; 13(4):377-83.

13. Najafi F, Dobson AJ, Jamrozik K. Is mortality from heart failure increasing in Australia? An analysis of official data on mortality for 1997-2003. Bull World Health Organ. 2006; 84(9):722-8.

14. Souza FMS, Timerman A, Serrano Jr VS, Santos RD, Mansur AP. Trends in the risk of mortality due to cardiovascular disease in five Brazilian geographic regions from 1979 to 1996. Arq Bras Cardiol. 2001;77(6):562-8.

15. Baena CP, Chowdhury R, Schio NA, Sabbag Jr AL, Guarita-Souza LC, Olandoski M, et al. Ischaemic heart disease deaths in Brazil: current trends, regional disparities and future projections. Heart. 2013;99(18):1359-64.

References

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16. Soares GP, Brum JD, Oliveira GMM, Klein CH, Souza e Silva NA. Evolution of socio-economic indicators and cardiovascular mortality in the Brazilian states, Arq Bras Cardiol. 2013;100(2):147-56.

17. Santo AH. III-defined causes of death and attended deaths, Brazil,2003. Rev Assoc Med Bras. 2008; 54(1):23-8.

18. Bocchi EA, Arias A, Verdejo H, Diez M, Gomez E, Castro P. The reality of heart failure in Latin America. J Am Coll Cardiol. 2013;62(11):949-58.

19. Murdoch, DR, Love MP, Robb TA, McDonagh TA, Davie AP,Ford I, et al. Importance of heart failure as a cause of death. Changing contribution to overall mortality and coronary heart disease mortality in Scotland 1979-1992. Eur Heart J.1998;19(12):1829-35.

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Fondaparinux versus Enoxaparin – Which is the Best Anticoagulant for Acute Coronary Syndrome? – Brazilian Registry DataAlexandre de Matos Soeiro,1 Pedro Gabriel Melo de Barros e Silva,2 Eduardo Alberto de Castro Roque,3 Aline Siqueira Bossa,1 Maria Cristina César,1 Sheila Aparecida Simões,2 Mariana Yumi Okada,2 Tatiana de Carvalho Andreucci Torres Leal,1 Fátima Cristina Monteiro Pedroti,3 Múcio Tavares de Oliveira Jr. 1

Unidade Clínica de Emergência - Instituto do Coração (InCor) do Hospital das Clínicas da Universidade de São Paulo;1 Hospital TotalCor,2 São Paulo, SP; Hospital Metropolitano,3 Serra, ES – Brazil

Mailing Address: Alexandre de Matos SoeiroRua João Moura, 870, 192b, Pinheiros. CEP 05412-002, São Paulo, SP – BrazilE-mail: [email protected] received February 21, 2016; revised manuscript June 15, 2016; accepted July 06, 2016.

DOI: 10.5935/abc.20160127

Abstract

Background: Recent studies have shown fondaparinux’s superiority over enoxaparin in patients with non-ST elevation acute coronary syndrome (ACS), especially in relation to bleeding reduction. The description of this finding in a Brazilian registry has not yet been documented.Objective: To compare fondaparinux versus enoxaparin in in-hospital prognosis of non-ST elevation ACS.Methods: Multicenter retrospective observational study. A total of 2,282 patients were included (335 in the fondaparinux group, and 1,947 in the enoxaparin group) between May 2010 and May 2015. Demographic, medication intake and chosen coronary treatment data were obtained. Primary outcome was mortality from all causes. Secondary outcome was combined events (cardiogenic shock, reinfarction, death, stroke and bleeding). Comparison between the groups were done through Chi-Square test and T test. Multivariate analysis was done through logistic regression, with significance values defined as p < 0.05.Results: With regards to treatment, we observed the performance of a percutaneous coronary intervention in 40.2% in the fondaparinux group, and in 35.1% in the enoxaparin group (p = 0.13). In the multivariate analysis, we observed significant differences between fondaparinux and enoxaparin groups in relation to combined events (13.8% vs. 22%. OR = 2.93, p = 0.007) and bleeding (2.3% vs. 5.2%, OR = 4.55, p = 0.037), respectively. Conclusion: Similarly to recently published data in international literature, fondaparinux proved superior to enoxaparin for the Brazilian population, with significant reduction of combined events and bleeding. (Arq Bras Cardiol. 2016; 107(3):239-244)Keywords: Acute Coronary Syndrome; Anticoagulants / therapeutic use; Enoxaparin / therapeutic use; Myocardial Infarction; Percutaneous Coronary Intervention; Hemorrhage.

Methods

Study PopulationThis is an observational multicenter retrospective study.

A total of 2,282 patients with NSTEACS admitted between May 2010 and May 2015 in the emergency sector were included. Patients were divided into two groups: fondaparinux (N = 335) and enoxaparin (N = 1,947). ST elevation was the only exclusion criterion employed. All patients were submitted to a cineangiocardiography.

Presence of ACS was considered in all patients who met the established criteria on the latest guidelines from the Brazilian Society of Cardiology and the American Heart Association.6,7 Non-ST elevation ACS was defined as the presence of chest pains associated to electrocardiographic alterations or troponin elevation/drop during hospital stay, or, in the absence of those, clinical conditions and risk factors compatible with unstable angina (severe or progressive chest pains at rest or at minimum effort). Major bleeding was defined using the BARC score8 types 3 and 5, and minor bleeding using types 1 and 2. Reinfarction was considered in the presence of chest pain reoccurrence associated with a new troponin elevation.

IntroductionThe use of anticoagulant agents in ACS is essential, impacting

on the reduction of events and mortality. However, the choice of a better anticoagulant therapy for patients with ACS is still controversial, and it is currently a widely discussed topic. Logic would state that, the more effective the anticoagulant, the higher the risk of bleeding and vice-versa.1,2

Recent studies have shown fondaparinux to be superior to enoxaparin for patients with non-ST elevation ACS (NSTEACS), especially in relation to bleeding.3-5 The description of this finding has yet to be documented in a Brazilian registry.

Thus, we have developed this study to compare fondaparinux to enoxaparin in in-hospital prognosis of NSTEACS in the Brazilian population.

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Ischemic stroke was considered in the presence of new motor focal neurological deficit confirmed by computerized tomography of the head. Patients on fondaparinux received an additional dose of unfractionated intravenous heparin when undergoing percutaneous coronary intervention (60 UI/kg when on glycoprotein IIb IIIa inhibitors, or 85 Ul/kg when patients were not on the medication).

The following data were obtained: age, gender, presence of diabetes mellitus, systemic arterial hypertension, smoking habit, dyslipidemia, family history of early onset coronary disease, previous coronary artery disease (previous angioplasty or coronary artery bypass surgery), hemoglobin, creatinine, peak troponin, Killip classification, left ventricle ejection fraction, medications used in the first 24 hours of hospital admission and adopted coronary treatment.

The study was submitted to and approved by the Research and Ethics Committee. Informed consent was filled out by all patients included in the study.

Statistical AnalysisPrimary outcome was in-hospital mortality from all causes.

Secondary outcome was combined events (cardiogenic shock, myocardial infarction, death, ischemic stroke and major bleeding). Descriptive analysis was done using means, minimum and maximum values. Comparisons between groups were done using Chi-Square test for categorical variables. For continuous variables, when Kolmogorov-Smirnov normality test showed normal distribution, the t test was used, with significance considered at p < 0.05. When the distribution did not follow the normality pattern, we used the Mann-Whitney U test. Multivariate analysis was done by logistic regression, with significance considered at p < 0.05. We considered all basal characteristics presented in Table 1 as variables in the analysis.

All calculations were done using the software SPSS v10.0.

ResultsMean age was 61 years old, and approximately 63% of

participants were male. The most prevalent risk factor was systemic arterial hypertension, in 71% of cases. Mean Mehran bleeding score was 16.2 versus 15.7 in fondaparinux and enoxaparin groups, respectively. In relation to treatment, we observed percutaneous coronary intervention in 40.2% in the fondaparinux group, and 35.1% in the enoxaparin group (p = 0.13). Coronary artery bypass surgery was done in 18.8% of the fondaparinux group versus 17.6% of the enoxaparin group (p = 0.031). In relation to the coronary arterial pattern, no significant differences were observed between the groups fondaparinux and enoxaparin, with 45.2% versus 43.6% one-vessel (p = 0.432), 20.1% versus 17.9% two-vessel (p = 0.567), and 22.3% versus 24.9% three-vessel (p = 0.871), respectively.

With regards to the occurrence of haemorrhagic complications, femoral artery pseudoaneurysm was the most frequent (56% of cases), followed by hemorrhagic stroke (18%) and high digestive bleeding associated to hemodynamic instability and/or drop in hemoglobin ≥ 3,0 g/dL (16%). No significant differences were observed between the types of bleeding related to enoxaparin versus fondaparinux.

In the comparison between the groups, significant differences were observed in relation to hypertension (67.8% vs. 73.6%, p < 0.0001); smoking (24.2% vs. 30.5%, p = 0.007); family history of early onset coronary disease (10.1% vs. 13.4%, p = 0.044); heart failure (10.7% vs. 8.8%, p = 0.039). killip classification > 2 2 (1.8% vs. 5.6%, p = 0.003); use of beta-blockers (96.1% vs. 87.4%, p < 0.0001); clopidogrel (65.4% vs. 67.9%, p < 0.038); glycoprotein IIbIIIa inhibitor (5.8% vs. 16.1%, p < 0.0001); and statins (98.5% vs. 93.8%, p < 0.0001). Basal characteristics of the studied population are depicted in Table 1.

In the multivariate analysis, significant differences were observed between the fondaparinux and enoxaparin groups in relation to combined events (13.8% vs. 22%, OR = 2.93, p = 0.007) and bleeding (2.3% vs. 5.2%, OR = 4.55, p = 0.037), respectively. Multivariate analysis results comparing different in-hospital outcomes between the groups are presented in Table 2 and Figure 1.

DiscussionThe present study showed important data reproduced

in the Brazilian population that are in line with results from recent publications from literature. We observed a significant reduction of bleeding and combined events during in-hospital evolution. With regards to mortality, no significant difference was found between fondaparinux and enoxaparin patients.

In 2006, the study OASIS-5 was published, which was a randomized work with 20,078 patients with NSTEACS that received 2.5 mg fondaparinux versus 1 mg/kg enoxaparin twice per day, effectively comparing the two anticoagulants. Similar results were observed as far as the primary outcome of the study in relation to combined events during hospital stay (death and reinfarction). However, after nine days, the highest rates of bleeding with fondaparinux use were significantly reduced in comparison to patients who received enoxaparin (2.2% vs. 4.1%, p < 0.001). Moreover, fondaparinux kept its superiority in relation to long-term bleeding and proved to be better in relation to 30-day mortality (2.9% vs. 3.5%, p = 0.02) and 180-day mortality (5.8% vs. 6.5%, p = 0.05).2,4,9

After the main study was published, there was still some doubt on whether the same results could be reproduced in the general population, with no specific selection criteria. However, fondaparinux use has considerably expanded, especially in Europe, becoming an Ib indication by the European Society of Cardiology in patients with NSTEACS, whereas enoxaparin remained an Ib indication through the same guidelines.10 Thus, some data banks were published, showing similar results to OASIS-5, but in real life. 3,5,11,12

Of all registries, the most impactful was the Swedish registry comparing fondaparinux to enoxaparin in approximately 40,000 patients with NSTEACS. Around 36.4% of those were treated with fondaparinux, and 63.6% with enoxaparin. Lower bleeding rates were observed comparatively between fondaparinux and enoxaparin (1.1% vs. 1.8%, OR = 0.54, CI 95% = 0.42 – 070). This was also reflected in lower in-hospital mortality rates in patients who received fondaparinux (2.7% vs. 4.0%, OR = 0.75, CI 95% = 0.63 – 0.89). After 30 and 180 days, differences related to mortality and bleeding were

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maintained between the groups. Such finding reflected, partially, what the OASIS-5 study had demonstrated, except this time, in a real population from a significant sample.5 This way, our study results are in line with what literature has been presenting, showing lower bleeding and combined event rates.

Undoubtedly, the main dif ferentiator between fondaparinux and enoxaparin is the lower risk of bleeding associated with its use. Even when there is percutaneous coronary intervention, or when it is associated to the use of glycoprotein IIbIIIa inhibitors, fondaparinux shows lower bleeding rates in comparison to enoxaparin.13,14 In 2009, Budaj et al.15 published an OASIS-5 study subanalysis, showing that this reduction happens in almost all types of bleeding when fondaparinux is used, with the exception of intracranial bleeding and bleeding related to surgeries, where no difference is found. Moreover,

justifying the importance of bleeding in patient evolution and its correlation to other outcomes, the authors showed a mortality of 8.4% vs. 2.7% (p < 0.0001), respectively, between patients who presented, or not, major bleeding.16 Even though we did not show, in our study, significant differences in relation to mortality, bleeding increase resulted in a higher number of combined events.

The justification for the lower bleeding rate is partly due to the use of one reduced anticoagulant dose when fondaparinux is administered. However, such dose of 2.5 mg per day was previously validated, showing that in the duration of a dual antiplatelet therapy, the required anticoagulant dose for a complete system block should possibly be reduced. Additionally, fondaparinux is a very specific and reversible factor Xa inhibitor, which means that, in theory, a smaller dose is amplified in terms of the anticoagulant effect.1

Table 1 – Basal clinical characteristics of patients on fondaparinux versus enoxaparin in the studied sample

Fondaparinux Enoxaparin p

Age (mean) 61 + 11.39 61.8 + 10.45 0.25

Male (%) 65.7% 62.6% 0.228

Diabetes Mellitus (%) 55.8% 46.9% 0.059

SAH (%) 67.8% 73.6% < 0.0001

Smoking (%) 24.2% 30.5% 0.007

FH Positive for CAD (%) 10.1% 13.4% 0.044

Dyslipidemia (%) 48.9% 51.2% 0.292

HF (%) 10.7% 8.8% 0.039

Previous stroke (%) 5.4% 4.9% 0.073

Previous AMI (%) 40.3% 36.8% 0.091

Previous CABS (%) 18.2% 16.0% 0.607

Previous CA (%) 22.7% 23.2% 0.773

Hb (%) (mean) 42.7 + 2.31 41.1 + 2.48 0.24

Peak troponin (mean) (ng/dL) 13.2 + 3.21 11.8 + 4.37 0.32

Cr (mg/dL) (mean) 1.25 + 0.54 1.52 + 0.67 0.168

SBP (mmHg) (média) 132.1 + 26.86 132.3 + 24.53 0.636

LVEF (%) (média) 56% + 13.4% 52.1% + 11.8% 0.586

Killip > 2 (%) 1.8% 5.6% 0.003

ASA (%) 98.5% 97.8% 0.87

Beta-blocker (%) 96.1% 87.4% < 0.0001

Clopidogrel (%) 65.4% 67.9% 0.038

GP Iib/IIIa inhibitor (%) 5.8% 16.1% < 0.0001

ACEI (%) 74.3% 69.2% 0.06

Statin (%) 98.5% 93.8% < 0.0001

SBP: systolic blood pressure; SAH: systemic arterial hypertension; FH: Family history; CAD: coronary artery disease; HF: heart failure; AMI: acute myocardial infarction; CABS: coronary artery bypass surgery; CA: coronary angioplasty; Hb: hemoglobin; CR: creatinine; LVEF: left ventricle ejection fraction; GP: glycoprotein inhibitor; ACEI: angiotensin converting enzyme inhibitor.

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Lastly, due to bleeding reduction and the consequent smaller rate of mortality and events stemming from fondaparinux use, several studies have shown better cost-benefit of its use in relation to enoxaparin.16-19 An OASIS-5 study subanalysis showed, after 180 days, an average cost reduction of up to 547 dollars per patient in the group that used fondaparinux, highlighting the medication’s superiority even further.16

Thus, fondaparinux use in NSTEACS patients has been expanding in Brazil and worldwide. In this scenario, a demonstration of the same benefit in a Brazilian registry is pivotal to give more security and reliability to the country.

Limitations

Despite our large sample, this is a retrospective study, and it presents a much larger number of patients on enoxaparin than on fondaparinux, We believe that such differences are based on attending physicians’ longer experience with patients on enoxaparin, especially since this medication has been in use for longer by the Brazilian population when compared to fondaparinux. Moreover, we do not have the description of the type of vascular access that was used, which can influence the bleeding rate associated to percutaneous coronary intervention. Percutaneous coronary intervention rate is

Table 2 – Multivariate analysis results comparing different in-hospital outcomes between the groups of patients on fondaparinux versus enoxaparin

Fondaparinux Enoxaparin OR CI 95% p

Reinfarction 6.1% 10.5% 1.23 0.27 - 5.62 0.7

Cardiogenic shock 2.1% 2.9% 6.38 0.80 - 50.78 0.08

Bleeding 2.3% 5.2% 4.55 1.09 - 18.91 0.037

Stroke 1.1% 0.6% 2.49 0.32 - 7.85 0.376

Mortality 2.2% 2.8% 1.71 0.49 - 5.93 0.125

Combined events 13.8% 22.0% 2.93 1.34 - 6.42 0.007

OR: Odds ratio; CI: confidence intervals.

Figure 1 – Comparative evaluation of mortality, combined events and bleeding between the groups fondaparinux and enoxaparin.

Fondaparinux Enoxaparin

Combined events

p = 0.007

13.80%

22.00%

2.20% 2.80% 2.30%

5.20%

p = 0.125

p = 0.037


Mortality


Bleeding

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considered relatively low, probably due to high complexity profile of patients involved in the study. Lastly, the use of glycoprotein IIbIIIa inhibitors was higher in the enoxaparin group, which may, partially, increase the bleeding rate in this group.

ConclusionSimilarly to the recently published data in international

literature, fondaparinux was proved superior to enoxaparin when administered in the Brazilian population, with significant reduction of combined events and bleeding.

Author contributionsConception and design of the research: Soeiro AM, Silva

PGMB, Leal TCAT, Oliveira Jr. MT; Acquisition of data: Soeiro AM, Silva PGMB, Roque EAC, Bossa AS, Simões SA, Okada MY, Leal TCAT, Pedroti FCM; Analysis and interpretation of the

data: Soeiro AM, Silva PGMB, Roque EAC, Bossa AS, César MC, Simões SA, Okada MY, Pedroti FCM; Statistical analysis: Soeiro AM, Silva PGMB, Bossa AS, César MC; Obtaining financing and Writing of the manuscript: Soeiro AM; Critical revision of the manuscript for intellectual content: Soeiro AM, Pedroti FCM, Oliveira Jr. MT.

Potential Conflict of InterestNo potential conflict of interest relevant to this article was

reported.

Sources of FundingThere were no external funding sources for this study.

Study AssociationThis study is not associated with any thesis or dissertation

work.

1. Simoons ML, Bobbink IW, Boland J, Gardien M, Klootwijk P, Lensing AW, et al; PENTUA Investigators. A dose-finding study of fondaparinux in patients with non-ST-segment elevation acute coronary syndromes: the Pentasaccharide in Unstable Angina (PENTUA) Study. J Am Coll Cardiol. 2004;43(12):2183-90.

2. Schiele F. Fondaparinux and acute coronary syndromes: update on the OASIS 5-6 studies. Vasc Health Risk Manag. 2010;6:179-87.

3. Schiele F, Meneveau N, Seronde MF, Descotes-Genon V, Dutheil J, Chopard R, et al; Reseau de Cardiologie de Franche Comte. Routine use of fondaparinux in acute coronary syndromes: a 2-year multicenter experience. Am Heart J. 2010;159(2):190-8.

4. Yusuf S, Mehta SR, Chrolavicius S, Afzal R, Pogue J, Granger CB, et al; Fifth Organization to Assess Strategies in Acute Ischemic Syndromes Investigators. Comparison of fondaparinux and enoxaparin in acute coronary syndromes. N Engl J Med. 2006;354(14):1464-76.

5. Szummer K, Oldgren J, Lindhagen L, Carrero JJ, Evans M, Spaak J, et al. Association between the use of fondaparinux vs low-molecular-weight heparin and clinical outcomes in patients with non-ST-segment elevation myocardial infarction. JAMA. 2015;313(7):707-16.

6. Nicolau JC, Timerman A, Marin-Neto JA, Piegas LS, Barbosa CJ, Franci A; Sociedade Brasileira de Cardiologia. [Guidelines of Sociedade Brasileira de Cardiologia for Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction (II Edition, 2007) 2013-2014 Update]. Arq Bras Cardiol. 2014;102(3 Suppl.1):1-61.

7. Jneid H, Anderson JL, Wright RS, Adams CD, Bridges CR, Casey DE Jr, et al; American College of Cardiology Foundation; American Heart Association Task Force on Practice Guidelines. 2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/non–ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. Circulation. 2012;126(7):875-910.

8. Mehran R, Rao SV, Bahht DL, Gibson M, Caixeta A, Eikelboom J, et al. Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the Bleeding Academic Research Consortium. Circulation. 2011;123(23):2736-47.

9. Majure DT, Aberegg SK. Fondaparinux versus enoxaparin in acute coronary syndromes. N Engl J Med. 2006;354(26):2829.

10. Roffi M, Patrono C, Collet J, Mueller C, Valgimigli M, Andreotti F, et al; Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology. 2015 ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J. 2016;37(3):267-315.

11. Permsuwan U, Chaiyakunapruk N, Nathisuwan S, Sukonthasarn A. Cost-effectiveness analysis of fondaparinux vs enoxaparin in non-ST elevation acute coronary syndrome in Thailand. Heart Lung Circ. 2015;24(9):860-8.

12. Kossovsky M, Keller PF, Mach F, Gaspoz JM. Fondaparinux versus enoxaprin in the management of acute coronary syndromes in Switzerland: a cost comparison analysis. Swiss Med Wkly. 2012;142:w13536.

13. Mehta SR, Granger CB, Eikelboom JW, Bassand JP, Wallentin L, Faxon DP, et al. Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes undergoing percutaneous coronary intervention: results from the OASIS-5 trial. J Am Coll Cardiol. 2007;50(18):1742-51.

14. Jolly SS, Faxon DP, Fox KA, Afzal R, Boden WE, Widimsky P, et al. Efficacy and safety of fondaparinux versus enoxaparin in patients with acute coronary syndromes treated with glycoprotein IIb/IIIa inhibitors or thienopyridines: results from the OASIS 5 (Fifth Organization to Assess Strategies in Ischemic Syndromes) trial. J Am Coll Cardiol. 2009;54(5):468–76.

15. Budaj A, Eikelboom JW, Mehta SR, Afzal R, Chrolavicius S, Bassand JP, et al; OASIS 5 Investigators. Improving clinical outcomes by reducing bleeding in patients with non-ST-elevation acute coronary syndromes. Eur Heart J. 2009;30(6):655-61.

16. Sculpher MJ, Lozano-Ortega G, Sambrook J, Palmer S, Ormanidhi O, Bakhai A, et al. Fondaparinux versus Enoxaparin in non-ST-elevation acute coronary syndromes: short-term cost and long-term cost-effectiveness using data from the Fifth Organization to Assess Strategies in Acute Ischemic Syndromes Investigators (OASIS-5) trial. Am Heart J. 2009;157(5):845-52.

17. Huber K, Bates ER, Valgimigli M, Wallentin L, Kristensen SD, Anderson JL, et al. Antiplatelet and anticoagulation agents in acute coronary syndromes: what is the current status and what does the future hold? Am Heart J. 2014;168(5):611-21.

References

243

Original Article


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18. Ross Terres JA, Lozano-Ortega G, Kendall R, Sculpher MJ. Cost-effectiveness of fondaparinux versus enoxaparin in non-ST-elevation acute coronary syndrome in Canada (OASIS-5). BMC Cardiovasc Disord. 2015;15(1):180.

19. Pepe C, Machado M, Olimpio A, Ramos R. Cost-effectiveness of fondaparinux in patients with acute coronary syndrome without ST-segment elevation. Arq Bras Cardiol. 2012;99(1):613-22.

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Complications after Surgical Procedures in Patients with Cardiac Implantable Electronic Devices: Results of a Prospective RegistryKatia Regina da Silva, Caio Marcos de Moraes Albertini, Elizabeth Sartori Crevelari, Eduardo Infante Januzzi de Carvalho, Alfredo Inácio Fiorelli, Martino Martinelli Filho, Roberto CostaInstituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), São Paulo, SP – Brazil

Mailing Address: Katia Regina da Silva •Unidade de Estimulação Elétrica e Marcapasso da Divisão de Cirurgia do InCor-HCFMUSPAvenida Dr. Eneas Carvalho de Aguiar, 44, Cerqueira César, Postal code 05403-000, São Paulo, SP – BrazilE-mail: [email protected], [email protected] received January 06, 2016; revised manuscript April 18, 2016; accepted April 20, 2016.

DOI: 10.5935/abc.20160129

Abstract

Background: Complications after surgical procedures in patients with cardiac implantable electronic devices (CIED) are an emerging problem due to an increasing number of such procedures and aging of the population, which consequently increases the frequency of comorbidities.

Objective: To identify the rates of postoperative complications, mortality, and hospital readmissions, and evaluate the risk factors for the occurrence of these events.

Methods: Prospective and unicentric study that included all individuals undergoing CIED surgical procedures from February to August 2011. The patients were distributed by type of procedure into the following groups: initial implantations (cohort 1), generator exchange (cohort 2), and lead-related procedures (cohort 3). The outcomes were evaluated by an independent committee. Univariate and multivariate analyses assessed the risk factors, and the Kaplan-Meier method was used for survival analysis.

Results: A total of 713 patients were included in the study and distributed as follows: 333 in cohort 1, 304 in cohort 2, and 76 in cohort 3. Postoperative complications were detected in 7.5%, 1.6%, and 11.8% of the patients in cohorts 1, 2, and 3, respectively (p = 0.014). During a 6-month follow-up, there were 58 (8.1%) deaths and 75 (10.5%) hospital readmissions. Predictors of hospital readmission included the use of implantable cardioverter-defibrillators (odds ratio [OR] = 4.2), functional class III –IV (OR = 1.8), and warfarin administration (OR = 1.9). Predictors of mortality included age over 80 years (OR = 2.4), ventricular dysfunction (OR = 2.2), functional class III–IV (OR = 3.3), and warfarin administration (OR = 2.3).

Conclusions: Postoperative complications, hospital readmissions, and deaths occurred frequently and were strongly related to the type of procedure performed, type of CIED, and severity of the patient’s underlying heart disease. (Arq Bras Cardiol. 2016; 107(3):245-256)

Keyworks: Pacemaker, Artificial; Surgery/complications; Intraoperative Complications/mortality; Defibrillators, Implantable.

for device maintenance or treatment of device-related complications.5

Despite a large increase in the number of procedures and the complexity of the cardiac devices, surprisingly little is known about the effectiveness and safety of these devices, and their impact on the patients’ mortality in Brazil. Recent statistics have reported increased complications rates after surgical procedures in patients with CIED, which have been disproportionately higher than the number of initial device implantations.6-12

The main factor associated with the increasing incidence of complications in patients with CIED is the aging of the population requiring conventional PM implants, which, in turn, is strongly associated with an increased rate of comorbidities and higher rates of hospital readmissions and mortality.6-11 Similarly, the incorporation of ICD and CRT as therapeutic modalities of artificial cardiac pacing has brought a new challenge to this field, since most candidates for these implant

IntroductionCardiac implantable electronic devices (CIED), including

pacemakers (PM), implantable cardioverter-defibrillators (ICD), and cardiac resynchronization therapy (CRT) without (CRT-P) or with defibrillator (CRT-D) are the main innovations in cardiology in the last decades.1 More than 737,000 procedures to implant these devices are performed every year worldwide,2-4 with an estimated annual average in Brazil of 35,000 new implants and 15,000 reoperations

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devices are patients with severe left ventricular dysfunction often refractory to pharmacological treatment for heart failure.13-16 Other factors also justifying the increasing number of complications include procedures to extract old leads, which carry a high surgical risk, and treatment of patients with CIED-related infections, who are often severely septicemic.6,7,17

In this study, we implemented a prospective registry gathering data from clinical practice with the purpose of (1) identifying the rates of complications, hospital readmissions, and perioperative mortality within the first 6 months of clinical follow-up, and (2) evaluate the risk factors associated with the occurrence of these events. These data are intended to modify routine protocols in order to prevent and treat these events at an early stage.

Methods

Study design and populationThe CIED Registry was a single-center prospective study

conducted in a hospital providing advanced care. The study was approved by our institution’s Research Ethics Committee, and the study participants signed a free and informed consent form.

We included all consecutive patients undergoing any type of surgical procedure involving artificial and permanent cardiac pacing between February and August 2011. The surgical procedures were performed by attending physicians, residents in cardiovascular surgery, and cardiologists undergoing training in artificial cardiac pacing.

All patients were followed up for 6 months after surgery through routine outpatient visits or, when attending other services, through telephone contact.

Study outcomesThe outcomes evaluated in the study included (1)

intraoperative and immediate postoperative complications, or complications within the first 6 months of clinical follow-up; (2) the need for hospital readmissions; and (3) mortality from any cause.

The complications were characterized as (1) major, when life-threatening or requiring surgical reintervention for correction; and (2) minor, when suitable for treatment on an outpatient basis, involving device reprogramming, or requiring exclusive clinical observation. All major complications, hospital readmissions, and deaths were evaluated by an independent expert committee.

Study dynamicsWe collected data at four distinct moments: immediately

before surgery (immediate preoperative), at hospital discharge, and at 30 days and 6 months after surgery. The figure 1 shows the main phases of the study and the composition of the studied population.

In the immediate preoperative period, we collected demographic and clinical data prior to the CIED implantation,

as well as information related to the clinical conditions of the patients upon collection of the data. When available, echocardiographic data were collected to determine the patients’ ventricular function. We estimated the patients’ left ventricular ejection fraction (LVEF) with the Teicholz method or, preferably, the Simpson method, considering as normal those values above 0.55.

In the assessments performed in the postoperative period and upon hospital discharge, we prioritized the evaluation of complications related to the surgical procedure, clinical complications arising from deterioration of the existing heart disease, and problems directly related to the CIED.

Electronic collection and management of the dataThe data were stored in a database developed in the

REDCap (Research Electronic Data Capture) software,18 which is hosted in our institution’s server.19

Studied variablesWe analyzed the following independent variables

potentially associated with a risk of occurrence of the studied outcomes: demographic data, preoperative baseline clinical data, type of CIED, and type of procedure performed.

To improve our understanding of the severity of the procedures performed, we grouped the patients into three distinct cohorts: (1) initial implantation of conventional PM, ICD, CRT-P, or CRT-D; (2) change of pulse generators or procedures limited to the pulse generator pocket, characterized in this study as low-risk reoperations; and (3) reoperations involving previously implanted leads, such as lead extraction or upgrade procedures, characterized as high-risk reoperations.

Statistical analysisThe data were electronically exported to Excel (Microsoft

Excel) spreadsheets and analyzed with SAS (Statistical Analysis System), SPSS (Statistical Package for the Social Sciences), and RStudio.

Quantitative variables are described as mean and standard deviation and qualitative variables as absolute and relative frequencies.

The association of independent variables with the occurrence of the evaluated outcomes was analyzed with chi-square or Fisher exact test. Differences in distribution of quantitative numerical variables according to the occurrence of outcomes (group with and without complications) were evaluated with Student’s t test. We used multivariate logistic regression with the stepwise variable selection to evaluate independent risk factors, including those variables with associations with a p value ≤ 0.10 in the univariate analysis. Based on the logistic regression model, we estimated the magnitude of the effect of the variables included in the final model by calculating the odds ratios (OR) and their respective 95% confidence intervals (CI). The probability of survival and hospital readmission-free survival were estimated by the Kaplan-Meier method. We adopted a significance level of 5% in the statistical tests.

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ResultsOver the 6-month inclusion period, 713 patients

underwent surgical procedures comprising 333 (46.7%) initial implantations, 304 (42.6%) low-risk reoperations, and 76 (10.7%) high-risk reoperations. The baseline characteristics of the patients are described in Table 1.

The patients were aged 4 days to 98.6 years with a median of 67.9 years. There was a slight predominance of males (51.5% of the cases). Most (66.4%) patients had no other heart disease apart from the underlying heart rate disturbance. Cardiomyopathy was diagnosed in 31.2% of the patients and was attributed to Chagas disease, or to idiopathic or ischemic causes. Only 1.1% of the patients presented a structural congenital heart disease.

The baseline assessment showed that most patients were oligosymptomatic in terms of manifestations of heart failure: 51.6% were in New York Heart Association (NYHA) functional class (FC) I, 33.2% in FC II, 14.0% in FC III, and 1.1% in FC IV.

Most patients presented with one or more comorbidities: 25.8% of the patients had one comorbidity, while 24.0% and 44.6% had two and three comorbidities, respectively. Only 5.6% of the patients had no other associated disease.

A total of 87.5% of the patients underwent echocardiographic studies. Among these patients, 49.8% had a normal LVEF, while 14.4% had LVEF estimated between 0.40 and 0.55, and 23.3% below 0.40.

During the 6-month follow-up period, adverse events were observed in 204 patients (28.6%). When considered individually, these events comprised 58 (8.1%) deaths, 75 (10.5%) hospital readmissions, 39 (5.5%) major complications, and 165 (23.1%) minor complications (Table 2).

Major complications were significantly more frequent (p = 0.014) in the cohort of patients undergoing high-risk reoperations (11.8%) when compared with those undergoing initial implantations (7.5%), and low-risk reoperations (1.6%). There were no significant differences in rates of minor complications among the three cohorts. The various types of complications observed are listed in Table 3. On univariate analysis, only administration of warfarin (p = 0.030) was identified as a risk factor for major complications, while no risk factors for minor complications were observed.

Of the 713 cases studied, 75 (10.5%) required readmission to the hospital within the first 6 months from the operation. In only 26 (3.6%) of these, the readmission was associated with problems related to cardiac pacing (Figure 2A). The expectation of being free from hospital readmission after 6 months of follow-up was 95% (95%CI = 94.9–95.1%), 87% (95%CI = 85.6–88.4%), and 82% (95%CI = 80.7–83.3%) for low-risk reoperations, initial implantation, and high-risk reoperations, respectively (Figure 2B). Figure 2B also shows that hospital readmissions were more frequent in patients undergoing high-risk reoperations (p < 0.001).

Figure 1 – Phases of the study and composition of the studied population. ICD: implantable cardioverter-defibrillator; CIED: cardiac implantable electronic device; PM: pacemaker; CRT: cardiac resynchronization therapy; CRT-D: cardiac resynchronization therapy associated with ICD; CRT-P: cardiac resynchronization therapy alone.

Patients referred to surgical procedures involving artificial cardiac pacing

Cohort 1 Initial CIED implantation (n=333)

PMn=262

PMn=258

PMn=40

ICDn=29

ICDn=28

ICDn=14

CRT-Pn=28

CRT-Pn=11

Surgical procedure

Inclus

ionGr

oup c

ompo

sition

Follo

w-up

Outco

mes

Postoperative complications Hospital admissions Mortality

Clinical follow-upHospital discharge, 1 and 6 months

CRT-Pn=12

CRT-Dn=14

CRT-Dn=7

CRT-Dn=10

Cohort 2 Generator exchange (n=304)

Cohort 3 Lead-related procedures (n=76)

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We identified the following risk factors for hospital readmission: ICD (OR = 4.19, 95%CI = 2.27–7.73) or CRT-D (OR = 3.20, 95%CI = 1.50–6.84) implants, preoperative NYHA FC III or IV (OR = 1.77, 95%CI = 1.03–3.04), and warfarin administration (OR = 1.95, 95%CI = 1.13–3.36). Patients undergoing low-risk reoperations had half the risk of hospital readmission than the other patients included in the study (Figure 3).

The general mortality rate was 8.1% after 6 months of follow-up. Only three deaths were related to problems with the artificial cardiac pacing (Figure 4A). The expected survival rates at 6 months of follow-up were 96% (95%CI = 95.9–96.1%), 93% (95%CI = 92.6–93.4%), and 89% (95%CI =

87.2–90.8%) for low-risk reoperations, high-risk reoperations, and initial implantations, respectively. As shown in Figure 4B, the mortality was higher in the cohort undergoing initial implantation (p = 0.002).

We identified the following risk factors for mortality: age over 80 years at surgery (OR = 2.44, 95%CI = 1.34–4.44), LVEF below 0.40 (OR = 2.20, 95%CI = 1.25–3.89), preoperative NYHA FC III or IV (OR = 3.31, 95%CI = 1.87–5.87), and warfarin administration (OR = 2.34, 95%CI = 1.33–4.12). Patients undergoing low-risk reoperations had half the risk of death from any cause when compared with the other patients in the study (Figure 5).

Table 1 - Demographic and baseline clinical characteristics

Demographic and Baseline Clinical Characteristics

Male gender, n (%) 367 (51.5)

Age

Mean ± SD (years) 64.5 ± 18.7

Range 4 days to 98.6 years

Baseline heart disease, n (%)

Without structural heart disease 412 (57.8)

Chagasic cardiomyopathy 87 (12.2)

Ischemic cardiomyopathy 59 (8.3)

Nonischemic cardiomyopathy 76 (10.7)

Congenital heart defect 8 (1.1%)

Others 42 (5.9)

Information not available 29 (4.1)

Associated comorbidities, n (%)

None 40 (5.6)

Only one 184 (25.8)

Two 171 (24.0)

Three 251 (35.2)

Four 67 (9.4)

Functional class (NYHA), n (%)

I 368 (51.6)

II 237 (33.2)

III 100 (14.0)

IV 8 (1.1)

Presence of atrial fibrillation 9 (1.3%)

Use of oral anticoagulants 97 (13.6)

Use of antiplatelet agents 277 (38.8)

LVEF, n (%)

Severe dysfunction (LVEF < 40) 166 (23.3)

Moderate dysfunction (LVEF ≥ 40 < 55) 103 (14.4)

Normal ventricular function (LVEF ≥ 55) 355 (49.8)

Information not available 89 (12.5)

SD: standard deviation; LVEF: left ventricular ejection fraction; NYHA: New York Heart Association.

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DiscussionComplications in surgical procedures for implantation or

maintenance of CIEDs occur frequently. These complications may result from skin punctures during venous access procedures, handling of vein and cardiac catheters, contamination by infectious agents, anesthetic procedures, or other situations that occur less frequently.6-12,20

Despite the fact that complications may occur at random, factors related to their increasing incidence have been described. For example, the experience of the hospital and the surgical team performing the procedure are strongly associated with the number of complications.21,22 The type of implanted device and surgery performed also influence the outcome of the procedure.8-17 Traditionally, surgeries for implantation of complex devices with a larger number of leads, as well as reoperations involving intravascular handling of the leads, particularly procedures to extract old leads, show a higher risk of complications.8,9,16,17

The rates of perioperative and postoperative complications in procedures related to CIED have increased considerably and in disproportion to the number of initial device implantation. Several factors may be related to this fact, including aging of the population, as well as increasing number of comorbidities and prescription of anticoagulants and antiplatelet agents.6-11 Another key factor is the incorporation into artificial cardiac pacing of cardioverter-defibrillators and CRT devices, which are mostly used to treat patients with severe left ventricular dysfunction.13-16, 23,24

The present study identified a high rate of intraoperative and postoperative complications, although these complications were mostly minor in nature and not life-threatening or requiring intervention or hospital readmission for their management. These minor complications occurred at random and were unrelated to the type of procedure performed. On the other hand, major complications that were life-threatening or required reintervention or hospital readmission were more frequent in initial implantations (7.5%), and significantly more frequently in high-risk reoperations (11.8%). These rates, although consistent, were lower than those of major complications reported in the REPLACE Registry, which ranged from 4.0% to 15.3% in patients undergoing generator exchange and upgrade procedures, respectively.8

Despite the high rate (10.5%) of hospital readmissions within 6 months from the surgical procedure, this rate was higher in patients undergoing high-risk reoperations, followed by those undergoing initial implantation. We also detected risk factors for this occurrence, mostly related to the severity of the heart disease, such as the requirement of any type of ICD or oral anticoagulant therapy, and preoperative NYHA FC III or IV. Data from the Danish Registry9 and the Medicare program21 have confirmed a higher morbidity rate with ICD alone or associated with CRT when compared with that with other devices.

Despite the high mortality rate from all causes observed in the same period (8.1%), this event was rarely related to the surgical procedure, but rather to the severity of the disease itself. We observed a higher risk of mortality among patients

Table 2 - Distribution of complications according to the type of procedure performed

Complications All (n= 713)

Initial implantation (n= 333)

Generator exchange (n= 304)

Lead-related procedures

(n= 76)p

Any complication 204 (28.6%) 99 (29.7%) 72 (23.7%) 31 (40.8%) NS

Major complications 39 (5.5%) 25 (7.5%) 5 (1.6%) 9 (11.8%) 0.014

Lead displacement 19 (2.7%) 14 (4.2%) - 5 (6.6%) NS

Cardiac tamponade 1 (0.1%) 1 (0.3%) - - NS

Hemothorax 3 (0.4%) 2 (0.6%) - - NS

Pneumothorax 7 (1.0%) 4 (1.2%) - 3 (3.9%) NS

Pocket abscess 3 (0.4%) 1 (0.3%) 2 (0.7%) - NS

Endocarditis 2 (0.3%) 1 (0.3%) 1 (0.3%) - NS

Lead fracture 1 (0.1%) - 1 (0.3%) - NS

DVT (ipsilateral upper extremity) 3 (0.4%) 2 (0.6%) - 1 (1.3%) NS

Minor complications 165 (23.1%) 78 (23.4%) 64 (21.1%) 23 (30.3%) NS

Phrenic stimulation / muscular 5 (0.7%) 3 (0.9%) 1 (0.3%) 1 (1.3%) NS

Pace / sense alterations 20 (2.85) 3 (0.9%) 16 (5.3%) 1 (1.3%) NS

Pocket hematoma 57 (8.0%) 35 (10.5%) 13 (4.3%) 9 (11.8%) NS

Pocket fluid 43 (6.0%) 14 (4.2%) 21 (6.9%) 8 (10.5%) NS

Superficial dehiscence 32 (4.5%) 17 (5.1%) 12 (3.9%) 3 (3.9%) NS

Surface wound infection 7 (1.0%) 5 (1.5%) 1 (0.3%) 1 (1.3%) NS

Skin scarification 1 (0.1%) 1 (0.3%) - - NS

NS: non-significant; DVT: deep venous thrombosis.

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Table 3 - Factors influencing the occurrence of complications

Factors associated with major complications Absence of complication Presence of complication p

Age 65.1 ± 18.6 64.9 ± 23.4 0.983

Male gender 48.4% 49.3% 0.851

Left ventricular ejection fraction 46.9 ± 21.6 53.2 ± 19.6 0.119

Type of cardiac device

Conventional PM 78.8% 77.6%

0.200

Conventional ICD 10.7% 6.7%

CRT-D 3.8% 6.7%

CRT-P 6.7% 8.9%

Baseline heart disease

Without structural heart disease 66.9% 64.1%

0.273

Chagasic cardiomyopathy 11.4% 18.3%

Ischemic cardiomyopathy 9.1% 6.9%

Nonischemic cardiomyopathy 11.4% 9.9%

Functional class (NYHA)

I - II 85.3% 82.8%0.807

III - IV 14.7% 17.2%

Multiple comorbidities 93.8% 97.1% 0.141

Use of antiplatelet agents 38.6% 40.3% 0.713

Use of warfarin 12.2% 19.4% 0.030*

Factors associated with minor complications Absence of complication Presence of complication p

Age 63.5 ± 19.8 65.3 ± 16.9 0.318

Male gender 48.6% 47.1% 0.860

Left ventricular ejection fraction 45.5 ± 22.7 48.8 ± 19.4 0.796

Type of cardiac device

Conventional PM 78.9% 70.6%

0.443Conventional ICD 9.8% 11.8%

CRT-D 4.4% 5.9%

CRT-P 6.9% 11.7%

Baseline heart disease

Without structural heart disease 66.8% 58.8%

0.540

Chagasic cardiomyopathy 12.3% 20.6%

Ischemic cardiomyopathy 8.5% 11.7%

Nonischemic cardiomyopathy 11.3% 8.8%

Functional class (NYHA)

I - II 84.8% 85.3%0.311

III - IV 15.2% 14.7%

Multiple comorbidities 94.4% 93.9% 0.707

Use of antiplatelet agents 38.6% 44.1% 0.522

Use of warfarin 13.6% 14.7% 0.798

ICD: implantable cardioverter-defibrillator; PM: pacemaker; CRT: cardiac resynchronization therapy; CRT-D: cardiac resynchronization therapy associated with ICD; CRT-P: cardiac resynchronization therapy alone.

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Figure 2 - Hospital readmission of patients with CIED during a follow-up period of 6 months after the surgical procedure. (A) Reasons for hospital readmission; (B) Estimated probability of being free from hospital readmission. CIED: cardiac implantable electronic device; AMI: acute myocardial infarction; Reop.: reoperation.

Heart failure

CIED-related

Arrhythmia

CIED infection

Infection unrelated to the CIED

AMI

Non-cardiac causes

B

Estim

ated p

roba

bility

of be

ing fr

ee fr

om ho

spita

l adm

ission

Initial implantation 87% [IC 95% 85.6-88.4]

Reop. low risk 95% [95%CI% 94.9-95.1]1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00 30

P < 0.001

60 90 120 150 180 210

Reop. high risk 82% [95%CI% 80.7-83.3]

Clinical follow-up (days)N. under risk

Initial implantation 319

297

69

308

295

68

303

293

66

298

291

63

294

290

62

291

288

62

288

288

62

Reop. low risk

Reop. high risk

24%17%

11%

5%

3%

12%

28%

who were either octogenarians, had severely decreased ventricular function or symptomatic heart failure, or received oral anticoagulant therapy. These rates are consistent with the mortality rates for heart failure reported in the Framingham Heart Study (10% in 30 days and 20–30% in 1 year),24 as well as the annual mortality rates of 9% and 12% described in the CARE-HF25 and COMPANION26 studies, respectively.

On the other hand, patients who underwent procedures to exchange pulse generators alone or other procedures that did not involve intravascular handling had significantly lower risks of death, hospital readmission, or complications than the patients in the other two cohorts. The fact that the majority of these patients had their procedures scheduled electively may have been crucial to their better outcomes.

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Literature studies about complications and mortality in patients with CIED are mainly based on secondary analyses of randomized clinical trials or observational studies with limited sample sizes. As far as we know, the sample of this prospective registry is the largest to assess postoperative outcomes in patients with CIED in a single cardiology center in Brazil. Another aspect to be noted is that the data presented in this study reflect a picture of real-world clinical practice, since the analysis included all patients seen during a limited period of time, regardless of age, medical condition or surgical procedure, thus avoiding selection biases that could have invalidated a generalization of the results.

Limitations of the studyThis study presents some limitations that must be considered

in the interpretation of the results. Although the study included a representative sample, it reflects the care practices of a single cardiology hospital in the country, which is considered a reference center providing advanced artificial cardiac pacing therapies and a cardiology training center. Since this study was not designed to assess the effects of each surgeon’s experience level and/or the volume of procedures performed individually, we are unable to claim that the surgeons’ positions on the learning curve influenced the higher risk of intraoperative complications. The possibility of such association will be assessed in future studies conducted at our institution. Finally, a long-term follow-up of this population

Figure 3 – Risk factors for hospital readmission in patients with CIED during a follow-up of 6 months after the surgical procedure. ICD: implantable cardioverter-defibrillator; FC: functional class; PM: pacemaker; Reop. : reoperation; CRT-D: cardiac resynchronization therapy associated with ICD; CRT-P: cardiac resynchronization therapy alone.

Variables

Age

0-30 1.36 (0.63 - 2.92)

1.11 (0.63 - 1.97)

1.00

1.00

1.00

1.00

1.00

1.00

0.51 (0.28 - 0.92)

1.77 (1.03 - 3.04)

1.95 (1.13 - 3.36)

1.55 (0.80 - 3.01)

1.62 (0.71 - 3.68)

4.19 (2.27 - 7.73)

3.20 (1.50 - 6.84)

40-59

60-79

>80

PM

CRT-P

ICD

CRT-D

Initial implantation

Reop. low risk

Reop. high risk

FC I – II

FC III – IV

Did not receive warfarin

Received warfarin

Odds ratio

0 1 2 3 4 5 6 7 8 9

OR (95%CI)

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Figure 4 – Mortality of patients with CIED during a follow-up of 6 months after the surgical procedure. (A) Mortality causes; (B) Estimated probability of survival. CIED: cardiac implantable electronic device; AMI: acute myocardial infarction; Reop.: reoperation.

B

Estim

ated p

roba

bility

of be

ing fr

ee fr

om

hosp

ital a

dmiss

ion

Initial implantation 89% [95%CI 87,2-90,8]

Reop. low risk 96% [95%CI 95,9-96,1]1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.00 30 60 90 120 150 180 210

P < 0,002

Reop. high risk 93% [95%CI 92,6-93.4]

Clinical follow-up (days)

N. under risk

Initial implantation 318 311 305 301 300 295 291

302 301 298 297 295 293 293

75 74 73 72 71 71 71

Reop. low risk

Reop. high risk

Heart failure

AMI

Sudden death

CIED infection

Other cardiac causes

undetermined

Non-cardiac causes

26%29%

12%

12% 5%5%

11%

is especially important to provide more robust evidence about possible adverse events that occur at later stages of care of patients with CIED, which are often underreported.

ConclusionsWe conclude that adverse perioperative and postoperative

events were frequent in the studied population. These events were strongly related to the type of procedure performed, type of device implanted, and, mainly, to the severity of the patient’s underlying heart disease. We identified risk factors for mortality and hospital readmission, confirming that serious events occur in

older patients and in those with more advanced cardiomyopathy.The findings of this study confirm a need for specific care

protocols to follow-up patients at a higher risk of presenting serious events.

Author contributionsConception and design of the research: Silva KR, Costa

R; Acquisition of data: Silva KR, Albertini CMM, Crevelari ES, Carvalho EIJ, Fiorelli AI; Analysis and interpretation of the data: Silva KR, Albertini CMM, Crevelari ES, Fiorelli AI, Costa R; Writing of the manuscript: Silva KR, Costa R; Critical

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Figure 5 - Risk factors for mortality in patients with CIED during a follow-up period of 6 months after the surgical procedure. ICD: implantable cardioverter-defibrillator; FC: functional class; PM: pacemaker; Reop. : reoperation; CRT-D: cardiac resynchronization therapy associated with ICD; CRT-P: cardiac resynchronization therapy alone; LVEF: left ventricular ejection fraction.

Variables

Age

0-30

40-59

60-79

>80

LVEF < 40%

LVEF ≥ 40%

Initial implantation

Reop. baixo risco

Reop. high risk

FC I – II

FC III – IV

Did not receive warfarin

Received warfarin 2.34 (1.33 - 4.12)

1.00

1.00

2.20 (1.25 - 3.89)

2.44 (1.34 - 4.44)

0.75 (0.37 - 1.55)

0.67 (0.16 - 2.85)

1.00

1.00

1.00

3.31 (1.87 - 5.87)

0.69 (0.29 - 1.65)

0.51 (0.26 - 1.01)

0 1 2 3 4 5 6 7

Odds ratio

OR (95%CI)

revision of the manuscript for intellectual content: Silva KR, Martinelli Filho M, Costa R.





work.

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1. Cheng A, Tereshchenko LG. Evolutionary innovations in cardiac pacing. J Electrocardiol. 2011;44(6):611-5.

2. Mond HG, Proclemer A. 11th world survey of cardiac pacing and implantable cardioverter-defibrillators: calendar year 2009--a World Society of Arrhythmia’s project. Pacing Clin Electrophysiol. 2011;34(8):1013-27.

3. 2012 ACCF/AHA/HRS Focused Update Incorporated Into the ACCF/AHA/HRS, Epstein AE, Di Marco JP, Ellenbogen KA, Estes NA 3rd, Freedman RA, Gettes LS, et al. 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. Circulation. 2013;127(3):e283-e352.

4. 2013 ESC, Brignole M, Auricchio A, Baron-Esquivias G, Bordachar P, Boriani G, Breithardt OA, et al. Guidelines on cardiac pacing and cardiac resynchronization therapy: The Task Force on cardiac pacing and resynchronization therapy of the European Society of Cardiology (ESC). Developed in collaboration with the European Heart Rhythm Association (EHRA). Europace. 2013;15(8):1070-118.

5. Ministério da Saúde. DATASUS. [Acesso em 2015 dez 30] Disponível em: http://www2.datasus.gov.br/DATASUS/index.php.

6. Rizwan Sohail M, Henrikson CA, Jo Braid-Forbes M, Forbes KF, Lerner DJ. Increased long-term mortality in patients with cardiovascular implantable electronic device infections. Pacing Clin Electrophysiol. 2015;38(2):231-9.

7. Greenspon AJ, Patel JD, Lau E, Ochoa JA, Frisch DR, Ho RT, et al. 16-year trends in the infection burden for pacemakers and implantable cardioverter-defibrillators in the United States 1993 to 2008. J Am Coll Cardiol. 2011;58(10):1001-6.

8. Poole JE, Gleva MJ, Mela T, Chung MK, Uslan DZ, Borge R, et al. Complication rates associated with pacemaker or implantable cardioverter-defibrillator generator replacements and upgrade procedures: results from the REPLACE registry. Circulation. 2010;122(16):1553-61.

9. Kirkfeldt RE, Johansen JB, Nohr EA, Jørgensen OD, Nielsen JC. Complications after cardiac implantable electronic device implantations: an analysis of a complete, nationwide cohort in Denmark. Eur Heart J. 2014;35(18):1186-94.

10. Palmisano P, Accogli M, Zaccaria M, Luzzi G, Nacci F, Anaclerio M, et al. Rate, causes, and impact on patient outcome of implantable device complications requiring surgical revision: large population survey from two centres in Italy. Europace. 2013;15(4):531-40.

11. Pakarinen S, Oikarinen L, Toivonen L. Short-term implantation-related complications of cardiac rhythm management device therapy: a retrospective single-centre 1-year survey. Europace. 2010;12(1):103-8.

12. Lin YS, Hung SP, Chen PR, Yang CH, Wo HT, Chang PC, et al. Risk factors influencing complications of cardiac implantable electronic device implantation: infection, pneumothorax and heart perforation: a nationwide population-based cohort study. Medicine (Baltimore). 2014;93(27):e213.

13. Masoudi FA, Mi X, Curtis LH, Peterson PN, Curtis JP, Fonarow GC, et al. Comparative effectiveness of cardiac resynchronization therapy with an implantable cardioverter-defibrillator versus defibrillator therapy alone: a cohort study. Ann Intern Med. 2014;160(9):603-11.

14. Krahn AD, Lee DS, Birnie D, Healey JS, Crystal E, Dorian P, et al. Predictors of short-term complications after implantable cardioverter-defibrillator replacement: results from the Ontario ICD Database. Circ Arrhythm Electrophysiol. 2011;4(2):136-42.

15. Steckman DA, Varosy PD, Parzynski CS, Masoudi FA, Curtis JP, Sauer WH, et al. In-hospital complications associated with reoperations of implantable cardioverter defibrillators. Am J Cardiol. 2014;114(3):419-26.

16. Borleffs CJ, Thijssen J, de Bie MK, van Rees JB, van Welsenes GH, van Erven L, et al. Recurrent implantable cardioverter-defibrillator replacement is associated with an increasing risk of pocket-related complications. Pacing Clin Electrophysiol. 2010;33(8):1013-9.

17. Brunner MP, Cronin EM, Duarte VE, Yu C, Tarakji KG, Martin DO, et al. Clinical predictors of adverse patient outcomes in an experience of more than 5000 chronic endovascular pacemaker and defibrillator lead extractions. Heart Rhythm. 2014;11(5):799-805.

18. Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap) - A metadata-driven methodology and workflow process for providing translational research informatics support, J Biomed Inform. 2009;42(2):377-81.

19. Silva KR, Costa R, Crevelari ES, Lacerda MS, Albertini CMM, Martinelli Filho M, et al. Glocal Clinical Registries: Pacemaker registry design and implementation for global and local integration - methodology and case study. PLoS One.2013;8(7):e71090.

20. Udo EO, Zuithoff NP, van Hemel NM, de Cock CC, Hendriks T, Doevendans PA, et al. Incidence and predictors of short- and long-term complications in pacemaker therapy: the FOLLOWPACE study. Heart Rhythm 2012;9:728-735.

21. Al-Khatib SM, Greiner MA, Peterson ED, Hernandez AF, Schulman KA, Curtis LH. Patient and implanting physician factors associated with mortality and complications after implantable cardioverter-defibrillator implantation, 2002-2005. Circ Arrhythm Electrophysiol. 2008;1(4):240-9.

22. Freeman JV, Wang Y, Curtis JP, Heidenreich PA, Hlatky MA. The relation between hospital procedure volume and complications of cardioverter-defibrillator implantation from the implantable cardioverter-defibrillator registry. J Am Coll Cardiol. 2010;56(14):1133-9

23. Al-Khatib SM, Hellkamp A, Bardy GH, Hammill S, Hall WJ, Mark DB, et al. Survival of patients receiving a primary prevention implantable cardioverter-defibrillator in clinical practice vs clinical trials. JAMA. 2013;309(1):55-62

24. Levy D, Kenchaiah S, Larson MG, Benjamin EJ, Kupka MJ, Ho KK, et al. Long-term trends in the incidence of and survival with heart failure. N Engl J Med.2002;347:1397–1402.

25. Cleland JG, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenberger L, et al. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med. 2005;352(15):1539-49.

26. Bristow MR, Saxon LA, Boehmer J, Krueger S, Kass DA, De Marco T, et al. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med. 2004;350(21):2140-50.

References

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Original Article

Prevalence and Phenotypic Expression of Mutations in the MYH7, MYBPC3 and TNNT2 Genes in Families with Hypertrophic Cardiomyopathy in the South of Brazil: A Cross-Sectional StudyBeatriz Piva e Mattos1, Fernando Luís Scolari2, Marco Antonio Rodrigues Torres1, Laura Simon3, Valéria Centeno de Freitas2, Roberto Giugliani4, Úrsula Matte5

Faculdade de Medicina – Universidade Federal do Rio Grande do Sul, Serviço de Cardiologia – Hospital de Clínicas de Porto Alegre1; Serviço de Cardiologia – Hospital de Clínicas de Porto Alegre2; Centro de Terapia Gênica – Hospital de Clínicas de Porto Alegre3; Instituto de Biociências – Universidade Federal do Rio Grande do Sul, Serviço de Genética Médica – Hospital de Clínicas de Porto Alegre4; Instituto de Biociências – Universidade Federal do Rio Grande do Sul, Unidade de Análise de Moléculas e Proteínas – Hospital de Clínicas de Porto Alegre5, RS – Brazil

Mailing Address: Beatriz Piva e Mattos •HCPA – UFRGS - Serviço de Cardiologia. Rua Ramiro Barcelos, 2350, Sala 2060, Rio Branco, Postal Code 90035-903, Porto Alegre, RS – BrazilE-mail: [email protected] received December 21, 2015; revised manuscript December 21, 2015; accepted May 24, 2016

DOI: 10.5935/abc.20160133

AbstractBackground: Mutations in sarcomeric genes are found in 60-70% of individuals with familial forms of hypertrophic cardiomyopathy (HCM). However, this estimate refers to northern hemisphere populations. The molecular-genetic profile of HCM has been subject of few investigations in Brazil, particularly in the south of the country.

Objective: To investigate mutations in the sarcomeric genes MYH7, MYBPC3 and TNNT2 in a cohort of HCM patients living in the extreme south of Brazil, and to evaluate genotype-phenotype associations.

Methods: Direct DNA sequencing of all encoding regions of three sarcomeric genes was conducted in 43 consecutive individuals of ten unrelated families.

Results: Mutations for CMH have been found in 25 (58%) patients of seven (70%) of the ten study families. Fourteen (56%) individuals were phenotype-positive. All mutations were missense, four (66%) in MYH7 and two (33%) in MYBPC3. We have not found mutations in the TNNT2 gene. Mutations in MYH7 were identified in 20 (47%) patients of six (60%) families. Two of them had not been previously described. Mutations in MYBPC3 were found in seven (16%) members of two (20%) families. Two (5%) patients showed double heterozygosis for both genes. The mutations affected different domains of encoded proteins and led to variable phenotypic expression. A family history of HCM was identified in all genotype-positive individuals.

Conclusions: In this first genetic-molecular analysis carried out in the south of Brazil, we found mutations in the sarcomeric genes MYH7 and MYBPC3 in 58% of individuals. MYH7-related disease was identified in the majority of cases with mutation. (Arq Bras Cardiol. 2016; 107(3):257-265)

Keywords: Mutation / genetics; Cardiomyopathy, Hypertrophic; Epidemiology; Sarcomeres; Ethnicity and Health.

IntroductionHypertrophic cardiomyopathy (HCM) is the most

prevalent genetic cardiovascular disease, affecting one in every 200 individuals.1-3 It is a global disease that occurs in many ethnic groups and in both sexes.3 HCM has an autosomal dominant pattern of inheritance, and incomplete, age- and gene-dependent penetrance.4,5 More than 1,500 causing mutations have been identified, mostly involving 11 genes that encode sarcomeric and Z-disc proteins.4-6 More recently, sarcomere mutations

in other cell structures have been detected, although its pathogenicity has not been established.5,6 HCM-causing mutations are usually identified in 60-70% of patients with familial disease, and 30-40% of patients with the sporadic form.2,4,6-10 The involvement of cardiac β-myosin heavy chain (MYH7) and myosin-binding protein C (MYBPC3) encoding genes is observed, respectively, in 25% to 35% of cases seen in the northern hemisphere.4,6,10,11 Troponin T gene (TNNT2) mutations are detected in 5% of patients, and mutations in other genes in a lower frequency (<1%). 5,6

The heterogeneous molecular substrate and variable phenotypic expression, characteristics of HCM, may be influenced by ethnic and geographical factors. However, the genetic profile of HCM has been established based on studies conducted mostly on northern hemisphere populations,7-9,12-30 whereas few similar studies have been carried out in the southern hemisphere.31-34 Compared with other countries, the genetic structure of Brazilian population is defined by a high degree of admixture between European, African and

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Arq Bras Cardiol. 2016; 107(3):257-265

Indian ancestors.35 Based on genetic aspects peculiar to the south of Brazil, characterized by a low degree of admixture among individuals with different ancestry, we have an interest in defining the genetic profile of HCM in this region.36

The aim of this study was to investigate mutations on the sarcomere genes MYH7, MYBPC3 and TNNT2 and genotype-phenotype associations in a cohort of HCM patients in the extreme south of Brazil.

Methods

Selection of patients and clinical evaluation A cross-sectional study was conducted on a convenience

sample of 43 consecutive individuals from 10 unrelated families, registered in the HCM outpatient care setting of a tertiary hospital in the south of Brazil. The first-degree relatives who first volunteered to participate during the recruitment period were enrolled in the study. All participants were from this region of the country.

The phenotype was defined by the identification of asymmetric left ventricular hypertrophy (LVH) in the echocardiogram, expressed by a maximum wall thickness ≥ 15 mm in any segment with a posterior septum/wall ratio ≥ 1.3, in the absence of chamber dilation or other conditions that may indicate similar changes. A maximum left ventricular (LV) wall thickness ≥ 13 mm in the anterior septal was the criterion used for the identification of HCM in the relat ives. Al l subjects underwent cardiovascular assessment by resting electrocardiogram and echocardiogram. Ten patients underwent coronary angiography. The study protocol was approved by the local Ethics Committee, and signed informed consent was obtained from all participants.

Molecular-Genetic analysis DNA was extracted from the peripheral blood according

to the technique described by Miller et al.37 Amplificatons of all the enconding regions of the sarcomeric genes MYH7 (38 exons), MYBPC3 (33 exons) and TNNT2 (15 exons) was performed by PCR,38 by using oligonucleotides available at htpp://www.cardiogenomics.org. The fragments were purified by Exo-SAP, according to the manufacturer’s instructions (USB Corporation, USA), followed by direct sequencing of the fragments using BigDye Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems, USA) and capillary electrophoresis using the ABI 3500 Genetic Analyzer (Applied Biosystems, USA). The resulting sequences were then compared with the reference sequences MYH7 – NM_000257, NP_000248; MYBPC3 – NM_000256, NP_000247; TNNT2 – NM_000364, NP_000355. The nomenclature for the description of sequence variants was established by following the Human Genome Variation Society recommendations.39 In some cases, analyses of cosegregation of the mutation and clinical data were conducted for pathogenicity definition.

In silico analysis was used to evaluate the effect of an aminoacid substitution based on the conservation of the regions affected, using the PolyPhen2,40 SIFT,41 PROVEAN,42

MutationTaster,43 and MutPred44 bioinformatic tools. The MutPred system was used to formulate hypothesis on structural and functional properties of mutation. Synonymous mutations and substitutions in introns and coding exons, neither reported as polymorphisms (SNPs) nor found on the 1000 Exome Variant Server (EVS) database were also evaluated by in silico analysis to identify potential splice site changes. NetGene245 and Human Splicing Finder46 were used to calculate the consensus values of potential splice sites.

Statistical analysis Quantitative data were expressed as mean and standard

deviation, and categorical variables as relative and absolute frequencies. The Shapiro-Wilk test was used to test normality of data, and differences between two groups, based on continuous and symmetrical variables were tested by Student’s t-test for independent samples. The categorical variables were compared by the chi-square test. Analyses were performed using the SPSS software, version 18.0 (SPSS Inc., Chicago Illinois, USA). Significance level was set at p <0.05.

Results

Clinical and molecular-genetic profileThe study group was composed of 10 consecutive

probands from unrelated families and 33 first-degree relatives. All participants were Caucasians. Clinical characteristics of the cohort are presented in Table 1.

HCM-causing mutations were detected in 25 (58%) subjects, 7 (70%) probands and 18 (54%) relatives, from 7 (70%) out of 10 study families. In the families with known mutations, mutations were detected in 18 (82%) of 22 relatives, but only 7 of them (32%) were classified as phenotype-positive. All phenotype-negative relatives (n=15;45%) were normal at clinical examination. In all 11 mutation carriers, without evidence of LVH by echocardiogram, abnormal electrocardiogram, including pathological Q-waves ≥ 3 mm and/or > 40 ms in two or more leads, except for aVR (n = 10;90%), fascicular block (n = 6;54%), deep S-waves in V2 > 25 mm (n = 3;27%), and negative T-waves > 3 mm (n = 1;1%) were detected.

All mutations identified were missense mutations, four (66%) in the MYH7 gene and two (33%) in MYBPC3. No mutation was detected in TNNT2. Two of the four mutations in MYH7 had not been reported in the literature. Mutations in this gene were identified in 20 (47%) individuals from six (60%) families, including the probands and 14 relatives. Mutations in the MYBPC3 gene were found in seven (16%) individuals from two (20%) families, including the probands and five relatives. In a single family, two individuals (5%) – the proband and a relative – had double heterozygosis with mutations both in the MYH7 and MYBPC3 genes (Figure 1). In three (30%) genotype-negative families, all members were clinically normal, whereas in the seven families in whom mutations were detected, 32% of the individuals were phenotype-positive. Characteristics of the mutations are described in Table 2 and results of pathogenicity analysis in Table 3.

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Mutations in the MYH7 geneIn the six (60%) families with HCM caused by the MYH7

gene, only 11 (55%) were phenotype-positive, the proband and five relatives. In the phenotype-positive individuals, the maximal wall thickness varied from 13 to 26 mm (mean of 20 ± 4 mm). In MYH7, four mutations were mapped. The substitution p.Ile263Thr was identified in only one family, affecting the proband only. The only relative who underwent genotyping was clinically normal and did not harbor a mutation. The p.Ala797Thr mutation was detected in two members of the same family, the proband and one relative phenotype-negative. This substitution, considered pathogenic exclusively by the MutPred system, has been reported in the 1000 EVS, with an allele frequency of 0.0002 in African-American population. Both mutations were associated with mild to moderate HCM, and with the obstructive forms of the disease. The p.Met877Ile

mutation, a mutation not previously described, was detected in three individuals of a four-member family. The mutation was considered a benign condition by four of the five in silico bioinformatic tools used in the study. However, it showed cosegregation with HCM phenotype in HCM patients, indicating a pathogenic effect. The proband had a phenotype of moderate HCM and left ventricular outflow tract obstruction. Severe mid-ventricular obstruction was identified in one family member and mild LVH was detected in another. None of these three mutations were related with a family history of sudden death. The p.Glu1468Lys mutation, identified in three families, had not been previously reported in the literature or in the EVS and SNP databases. Nevertheless, all bioinformatic tools favored its pathogenic potential. Analysis of cosegregation showed that all family members affected were also carriers of mutations, except for one, who was considered normal.

Table 1 – Clinical characteristics of a cohort of patients with hypertrophic cardiomyopathy in the south of Brazil, composed of 10 unrelated probands and 33 relatives

Characteristics Probands (n = 10) Relatives (n = 33)

Phenotype-positive (n = 7)

Phenotype-negative (n = 26)

Age (years) 53 ± 7 42 ± 20 32 ± 17

Racial group

Caucasians 10 (100%) 7 (100%) 26 (100%)

Female 5 (50%) 4 (57%) 17 (65%)

Family history

HCM 7 (70%) 7 (100%) 15 (58%)

Sudden cardiac death 2 (20%) 4 (57%) 8 (30%)

Age at the onset of disease (years) 44 ± 12 39 ± 20 -

NYHA functional class

I/II 5 (50%) 5 (71%) -

III/IV 5 (50%) 2 (29%) -

Echocardiogram

Left atrial diameter (mm) 46 ± 5 38 ± 8 32 ± 7

LV end-diastolic diameter (mm) 43 ± 5 47 ± 5 45 ± 4

LV end-systolic diameter (mm) 25 ± 3 26 ± 3 25 ± 3

LV maximal parietal thickness (mm) 20 ± 4 20 ± 5 9 ± 7

Ejection fraction % 72 ± 6 74 ± 5 71 ± 5

LV outflow tract obstruction 7 (70%) - -

LV mid-ventricular obstruction 1 (10%) 2 (29%) -

LV outflow gradient (mmHg) 45 ± 33 - -

Treatment

Alcohol septal ablation 3 (30%) - -

Myectomy 1 (10%) - -

Double-chamber pacemaker 4 (40%) - -

Implantable cardioverter defibrillator 2 (20%) 1 (14%) -

Data expressed in mean ± standard deviation; HCM: hypertrophic cardiomyopathy; NYHA: New York Heart Association; LV: left ventricular.

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Figure 1 – Distribution of mutations in the sarcomeric genes MYH7 and MYBPC3 in a population with hypertrophic cardiomyopathy. Individuals with double heterozygosity were included in this subgroup only.

18 (42%) With no mutation

2 (5%) Double heterozygosity 3 (7%) MYBPC3

Phenotype-positive

10 (22%) MYH7 Phenotype-positive

2 (5%) MYBPC3 Phenotype-negative

8 (19%) MYH7 Phenotype-negative

Table 2 – Mutations in the sarcomeric genes MYH7 and MYPC3 in the study population

Gene/Exon Mutation/Domain Change of aminoacid Families

Number of patients affected

(phenotype +/phenotype -)

Cosegregation Phenotype

MYH7

9 Missense/Head p.Ile263Thr IX 1/0 NT Mild, obstructive LVH

21 Missense/ Domain IQ p.Ala797Thr VI 1/1 NT Moderate, obstructive LVH

22 Missense/Neck p.Met877Ile V 3/0 YesMild to severe LVH, non-obstructive or with outflow tract obstruction, or

mid-ventricular obstruction

32 Missense/Rod p.Glu1468Lys IV, VIII, X 6/8* Yes

Mild to severe LVH, non-obstructive or with outflow tract obstruction,

or mid-ventricular obstruction, late sudden death

MYBPC3

18 Missense/C4 p.Arg495Gln III 3/2 YesModerate to massive LVH, non-obstructive form of early onset,

premature sudden death

25 Missense/C6 p.Val896Met VIII 1/1** NT Moderate, obstructive LVH

Domain IQ: calmodulin binding domain; NT: not tested; LVH: left ventricular hypertrophy; *associated with p.Val896Met (MYBPC3), n = 2; **associated with p.Glu1468Lys (MYH7), n = 2.

In one of the families, although the mutation was identified in the proband and in six of seven members evaluated, only three of them were phenotype-positive. The proband and one of the family members had non-obstructive, moderate HCM. Mid-ventricular obstruction was identified in another

family member, who died suddenly at the age of 66 during the study period. In another family with this mutation, the proband and four relatives had this genotype, although only two were phenotype-positive. Two individuals, one proband and one young, phenotype-negative relative, showed a

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Table 3 – Analysis of pathogenicity of the mutations in MYH7 e MYBPC3 genes

Mutation PolyPhen2 SIFT PROVEAN MutationTaster MutPred

p.Ile263Thr Benign Deleterious Deleterious Deleterious Deleterious

p.Ala797Thr Benign Benign Benign Benign Deleterious

p.Met877Ile Benign Benign Benign Deleterious Benign

p.Glu1468Lys Deleterious Deleterious Deleterious Deleterious Deleterious

p.Arg495Gln Deleterious Benign Benign Deleterious Deleterious

p.Val896Met Benign Deleterious Benign Benign Deleterious

double heterozygosis with mutations both in MYH7 and MYBPC3. The proband had moderate LVH and severe left ventricular outflow tract obstruction, whereas the relative with isolated mutation in MYH7 had mild, non-obstructive form of the disease. In the third family affected, the proband and one young, phenotype-negative relative were carriers of this mutation, which associated with moderate LVH and severe left ventricular outflow tract obstruction.

Mutations in the MYBPC3 geneIn the two (20%) families with mutations in the MYBPC3

gene, four (57%) of the carriers were phenotype-positive, the proband and two relatives. The mutations led to LVH with marked inter- and intrafamilial variability, expressed by a maximal wall thickness of LV varying from 17 to 34 mm, and mean of 23 ± 7 mm. The mutation p.Arg495Gln was identified in one family, in the proband and in four of the five members who underwent genotyping, two of them phenotype-positive. The analysis of cosegregation in this family and three in silico bioinformatic tools favored the pathogenic role of this mutation in HCM. The mutation was related to early onset and to non-obstructive forms with mild to massive LVH associated with a family history of premature sudden death. The mutation p.Val896Met was found in two subjects of a six-member family, who were also carriers of the mutation p.Glu1468Lys in the MYH7 gene. Two programs indicated the pathogenic effect of this variant, which was also reported in the EVS, with an allele frequency of 0.0015 and 0.0048 in African- and European-origin individuals respectively.

The comparison of c l inical var iables between genotype-positive and genotype-negative subjects revealed that a family history of HCM and/or sudden death was more frequent in those in whom a mutation was identified (Table 4). Clinical indicators were not significantly different between carriers of mutations of the two genes, except for a lower age and a family history of sudden death, which associated with HCM caused by MYBPC3 (Table 5).

DiscussionThe present study represents the first genetic-molecular

analysis of HCM conducted on a population from the extreme south of Brazil, composed of members of unrelated families. A sample of consecutive index-patients and their respective relatives, considered representative of a cohort of non-referred HCM outpatients was studied.

Causing mutations were detected in 58% of subjects and 70% of the families. Mutations in MYH7, identified in 47% of patients, were more frequent than mutations in MYBPC3, found in 16% of patients. Most mutations were private. Two mutations in the MYH7 gene were considered novel. A positive genetic test in the proband enabled the molecular identification of the disease in up to 82% of the respective relatives, 39% of them phenotype-positive. All mutation carriers without evidence of HCM in the echocardiogram had evidence of abnormal electrocardiogram findings, especially pathological Q-waves, which may suggest a pre-clinical stage of disease.47

HCM is considered a worldwide disease, affecting different populations exposed to a large variety of environmental and geographic factors. Although the phenotypic expression of HCM does not show evidence of differences between the northern and southern hemisphere populations, it is still not clear whether they share the same genetic substrate. Molecular analysis of HCM patients from multiple geographic regions and ethnic groups would certainly contribute to the understanding of the complex characteristics of this condition. The genetic profile of HCM was defined based on investigations on unrelated populations in Europe and North America.7-9,12-24 More recently, the genetic-molecular analysis has been extended to cohorts in Asia,25,26,28,30 North Africa and Australia.32 On the other hand, data from populations from the south hemisphere are still scarce.31-34 In our country, molecular characteristics of HCM have been determined in patients from the southeast, north and northeast regions.34 The incorporation of more resolutive genetic tests to clinical practice would certainly expand their use in all continents.

In the present analysis, causing mutations were more frequent as compared with previous studies that included familial and sporadic HCM.8,9,18,19, 22-27 This may be explained by the fact that our study group was composed of a well-characterized sample of individuals with HCM, even though it is known that the identification of mutations varies according with the study populations.10 All mutations detected in MYH7 and MYBPC3 were missense mutations. No mutation was found in the TNNT2 gene, which may be explained by the lower prevalence of the gene in general population and the relatively older age of our sample, since the TNNT2 gene is associated with an early onset and premature sudden death.4,6,13 In contrast to previous studies conducted on northern hemisphere populations,7,8,11,22,23,27,48

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Table 4 – Comparison of clinical characteristics between genotype-positive and genotype-negative subjects

Characteristics Genotype-positive (n = 25)

Genotype-negative (n = 18) p

Age (years) 41 ± 19 35 ± 17 0.3

Gender

Male 13 (52%) 4 (22%)0.08

Female 12 (48%) 14 (78%)

Family history

HCM 25 (100%) 4 (22%) 0.0001

Cardiac sudden death 12 (48%) 2 (11%) 0.019

Data expressed in mean ± standard deviation; HCM: hypertrophic cardiomyopathy.

Table 5 – Comparison of clinical characteristics of carriers of mutations in the MYH7 and MYBPC3 gene

MYH7 (n = 20)

MYBPC3 (n = 7) p

Age (years) 48 ± 19 32 ± 16 0.102

Age at the onset of disease (years) 47 ± 13 25 ± 13 0.0001

Gender

Male 13 (65%) 5 (71%)0.127

Female 7 (35%) 2 (29%)

Family history

HCM 20 (100%) 7 (100%) -

Sudden death 7 (35%) 5 (71%) 0.016

NYHA functional class

I/II 15 (75%) 6 (86%)0.246

III/IV 5 (25%) 1 (14%)

Left atrial diameter (mm) 40 ± 6 33 ± 7 0.082

LV diastolic diameter (mm) 45 ± 5 40 ± 4 0.06

LV systolic diameter (mm) 26 ± 4 24 ± 2 0.195

LV maximal parietal thickness (mm) 15 ± 6 19 ± 10 0.274

Ejection fraction (%) 67 ± 19 70 ± 3 0.497

LV outflow tract obstruction 6 (30%) 1 (14%) 0.133

Data expressed in mean ± standard deviation; HCM: hypertrophic cardiomyopathy; NYHA: New York Heart Association; LV: left ventricular.

mutations in MYH7 were more frequent than in MYBPC3. This characteristic was described in HCM patients from other regions in Brazil, and may represent a particularity of the disease in our country.34

Mutations in MYH7 were found in 47% of patients that underwent genotyping and in 60% of the families. The screening of all coding regions of this gene identified the presence of four missense mutations in different protein domains. The mutation p.Ile263Thr has been previously reported in France,7,22 Portugal,23 and more recently, in other regions in Brazil.34 The mutation p.Ala797Thr has been previously reported in South Africa, with a possible founder effect, and in other cohorts in North America,8

North Africa,27 Europe9,23,24 Europe, as well as in Brazil.34 The mutation p.Met877Ile, novel, was mapped in one family with high degree of penetrance, affecting three of the four genotyped members of two generations. The mutation was associated with low to severe LVH, mid-ventricular and left ventricular outflow tract obstruction, and non-obstructive condition. The p.Glu1468Lys mutation, also considered novel, was identified in three unrelated families. Inter- and intrafamilial phenotypic variability was observed in obstructive and non-obstructive HCM, with mild to moderate LVH. This mutation was also related to mid-ventricular obstruction associated with late sudden death in one family member.

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Missense mutations in the MYBPC3 gene were found in 16% of patients and 20% of the families. The p.Arg495Gln mutation has been previously described in North America,20 Portugal,23 and reported as a frequent mutation in a cohort of HCM patients in Brazil.34 In this study, the mutation was identified in a family with history of premature sudden death and mild to massive LVH. The mutation p.Val896Met has been previously detected in European7,23 and South African31 cohorts. Two carriers of this mutation, a proband with moderate LVH and severe left ventricular outflow tract obstruction and a phenotype-negative young relative, also had the p.Glu1468Lys mutation in MYH7. This phenotype-negative individual showed pathological Q-waves in resting electrocardiogram. Double or compound heterozygosity have been usually identified in families with mutations in MYBPC3, representing 3-5% of HCM patients.7,20 Multiple mutations are commonly related to severe phenotypes and early onset disease, although varied degrees of LVH have been reported in these individuals.34

All mutations in the MYH7 e MYBPC3 genes showed marked intra- and interfamilial phenotypic variability, related to the degree of LVH. Phenotypic variability in carriers of the same mutation is considered a characteristic of HCM.10 The patterns of LVH and the age of disease onset may differ even between related subjects, since the phenotype is determined not only by the mutation per se, but also by the interaction of polymorphisms, modifying genes, and epigenetic and environmental factors.6,10 The meta-analysis of the genotype-phenotype associations in HCM showed that, due to the fact that many mutations are exclusive of a unique family, the studies conducted so far have not exhibited sufficient statistical power to reach definite conclusions.48 Nevertheless, some clinical variables may be related to the genotype, such as age, maximal wall thickness of LV and family history of HCM or sudden death. In our study group, there was a predominance of a family history of sudden death and the onset of the disease at an early age in carriers of mutation in the MYBPC3 gene. These characteristics are different from those previously reported, but may represent a particularity of our group.

In 30% of the families, no causing mutation was identified and, in all these cases, there was no clinical history of HCM. The presence of a negative genetic test may result from the presence of mutations in unknown or unsequenced genes. LVH does not constitute a specific phenotype and may be identified in other heart conditions, seen as phenocopies of HCM. The detection of mutations in HCM-related sarcomeric genes has been associated with a family history or early onset of the disease, unfavorable prognosis and higher degree of LVH compared with patients with negative genetic tests.9,25,27 Recent data have indicated that this association occurs independently of the gene involved, although further studies to confirm this observation are still needed.2 In our study, a family history of HCM or sudden death was more frequent in genotype-positive individuals than in genotype-negative ones.

In this study, HCM causing mutations were identified in a considerable number of patients. However, the genetic profile of our population was not essentially different from that reported in cohorts of different ethnicities from other geographic regions, except for the fact that mutations in the MYH7 gene were more frequent than in MYBPC3.

Limitations of the study The study consisted of the screening of the three most

prevalent genes in HCM, but it did not include other genes of lower prevalence. Nevertheless, the analysis was restricted to a sample of unrelated families, registered in a unique tertiary care center located in the south of Brazil.

ConclusionsIn this first molecular-genetic analysis of a HCM cohort

in the extreme south of Brazil, mutations were identified in 58% of consecutive individuals of unrelated families. The mutations affected predominantly the MYH7 gene; this finding is different from that reported in northern hemisphere countries. Our study supports that mutations in MYH7 and MYBPC3 should be the first focus of molecular-genetic analysis in HCM, and that mutations in TNNT2 have a low prevalence in Brazilian population. All mutations detected were missense mutations, whereas two mutations in MYH7 had not been described before. The mutations affected different domains of the encoded proteins and determined variable phenotypic expressions. There was a relationship between a positive genetic test and a family history of HCM or sudden death. The predominance of mutations in the MYH7 gene may be a characteristic of the local population.

Author contributionsConception and design of the research: Piva e Mattos BP,

Scolari FL, Torres MAR, Freitas VC, Giugliani R, Matte U; Acquisition of data: Mattos BP, Scolari FL, Torres MAR, Simon L, Freitas VC, Giugliani R, Matte U; Analysis and interpretation of the data: Mattos BP, Scolari FL, Simon L, Matte U; Statistical analysis and Writing of the manuscript: Mattos BP, Scolari FL; Obtaining financing: Mattos BP; Critical revision of the manuscript for intellectual content: Mattos BP, Matte U.


was reported.

Sources of FundingThis study was funded by Fundo de Incentivo à Pesquisa

do Hospital de Clínicas de Porto Alegre.


work.

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1. Gersh BJ, Maron BJ, Bonow RO, Dearani JA, Fifer MA, Link MS, et al; American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines; American Association for Thoracic Surgery; American Society of Echocardiography; American Society of Nuclear Cardiology; Heart Failure Society of America; Heart Rhythm Society; Society for Cardiovascular Angiography and Interventions; Society of Thoracic Surgeons. 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2011;124(24):e783-831.

2. Elliot PM, Anastasakis A, Borger MA, Borggrefe M, Cecchi F, Charron P, et al. 2014 ESC Guidelines on diagnosis and management of hypertrophic cardiomyopathy: the task force for the diagnosis and management of hypertrophic cardiomyopathy of the European Society of Cardiology (ESC). Eur Heart J. 2014;35(39):2733-79.

3. Semsarian C, Ingles J, Maron MS, Maron BJ. New perspectives on the prevalence of hypertrophic cardiomyopathy. J Am Coll Cardiol. 2015;65(12):1249-54.

4. Jacoby D, McKenna WJ. Genetics of inherited cardiomyopathy. Eur Heart J. 2012;33(3):296-304.

5. Maron BJ, Maron MS, Semsarian C. Genetics of hypertrophic cardiomyopathy after 20 years: clinical perspectives. J Am Coll Cardiol. 2012;60(8):705-15.

6. Ho CY, Charrin P, Richard P, Girolami F, Van Spaendonck-Zwarts KY, Pinto Y. Genetic advances in sarcomeric cardiomyopathies: state of the art. Cardiovasc Res. 2015;105(4):397-408.

7. Richard P, Charron P, Carrier L, Ledeuil C, Cheav T, Pichereau C, et al; EUROGENE Heart Failure Project. Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy. Circulation. 2003;107(17):2227-32. Erratum in: Circulation. 2004;109(25):3258.

8. Van Driest SL, Jaeger MA, Ommen SR, Will ML, Gersh BJ, Tajik AJ, et al. Comprehensive analysis of the beta-myosin heavy chain gene in 389 unrelated patients with hypertrophic cardiomyopathy. J Am Coll Cardiol. 2004;44(3):602-10.

9. Olivotto I, Girolami F, Ackerman MJ, Nistri S, Bos JM, Zachara E, et al. Myofilament protein gene mutation screening and outcome of patients with hypertrophic cardiomyopathy. Mayo Clin Proc. 2008;83(6):630-8.

10. Landstrom AP, Ackerman MJ. Mutation type is not clinically useful in predicting prognosis in hypertrophic cardiomyopathy. Circulation. 2010;122(23):2441-9.

11. Maron BJ, Ommen SR, Semsarian C, Spirito P, Olivotto I, Maron MS. Hypertrophic cardiomyopathy: present and future, with translation into contemporary cardiovascular medicine. J Am Coll Cardiol. 2014;64(1):83-99. Erratum in: J Am Coll Cardiol. 2014;64(11):1188.

12. Geisterfer-Lowrance AA, Kass S, Tanigawa G, Vosberg HP, McKenna W, Seidman CE, et al. A molecular basis for familial hypertrophic cardiomyopathy: a beta cardiac myosin heavy chain gene missense mutation. Cell. 1990;62(5):999-1006.

13. Thierfelder L, Watkins H, MacRae C, Lamas R, McKenna W, Vosberg HP, et al. Alpha-tropomyosin and cardiac troponin T mutations cause familial hypertrophic cardiomyopathy: a disease of the sarcomere. Cell. 1994;77(5):701-12.

14. Watkins H, Conner D, Thierfelder L, Jarcho JA, MacRae C, McKenna WJ, et al. Mutations in the cardiac myosin binding protein-C gene on chromosome 11 cause familial hypertrophic cardiomyopathy. Nat Genet. 1995;11(4):434-7.

15. Poetter K, Jiang H, Hassanzadeh S, Master SR, Chang A, Dalakas MC, et al. Mutations in either the essential or regulatory light chains of myosin are associated with a rare myopathy in human heart and skeletal muscle. Nat Genet. 1996;13(1):63-9.

16. Kimura A, Harada H, Park JE, Nishi H, Satoh M, Takahashi M, et al. Mutations in the cardiac troponin I gene associated with hypertrophic cardiomyopathy. Nat Genet. 1997;16(4):379-82.

17. Mogensen J, Klausen IC, Pedersen AK, Egeblad H, Bross P, Kruse TA, et al. Alpha-cardiac actin is a novel disease gene in familial hypertrophic cardiomyopathy. J Clin Invest. 1999;103(10):R39-43.

18. Morner S, Richard P, Kazzam E, Hellman U, Hainque B, Schwartz K, et al. Identification of the genotypes causing hypertrophic cardiomyopathy in northern Sweden. J Mol Cell Cardiol. 2003;35(7):841-9.

19. Erdmann J, Daehmlow S, Wischke S, Senyuva M, Werner U, Raible J, et al. Mutation spectrum in a large cohort of unrelated consecutive patients with hypertrophic cardiomyopathy. Clin Genet. 2003;64(4):339-49.

20. Van Driest SL, Vasile VC, Ommen SR, Will ML, Tajik AJ, Gersh BJ, et al. Myosin binding protein C mutations and compound heterozygosity in hypertrophic cardiomyopathy. J Am Coll Cardiol. 2004;44(9):1903-10.

21. Oliva-Sandoval MJ, Ruiz-Espejo F, Monserrat L, Hermida-Prieto M, Sabater M, García-Molina E, et al. Insights into genotype-phenotype correlation in hypertrophic cardiomyopathy. Findings from 18 Spanish families with a single mutation in MYBPC3. Heart. 2010;96(24):1980-4.

22. Millat G, Bouvagnet P, Chevalier P, Dauphin C, Jouk PS, Da Costa A, et al. Prevalence and spectrum of mutations in a cohort of 192 unrelated patients with hypertrophic cardiomyopathy. Eur J Med Genet. 2010;53(5):261-7.

23. Brito D, Miltenberger-Miltenyi G, Vale Pereira S, Silva D, Diogo AN, Madeira H. Sarcomeric hypertrophic cardiomyopathy: genetic profile in a Portuguese population. Rev Port Cardiol. 2012;31(9):577-87.

24. Berge KE, Leren TP. Genetics of hypertrophic cardiomyopathy in Norway. Clin Genet. 2014;86(4):355-60.

25. Otsuka H, Arimura T, Abe T, Kawai H, Aizawa Y, Kubo T, et al. Prevalence and distribution of sarcomeric gene mutations in Japanese patients with familial hypertrophic cardiomyopathy. Circ J. 2012;76(2):453-61.

26. Liu W, Liu W, Hu D, Zhu T, Ma Z, Yang J, et al. Mutation spectrum in a large cohort of unrelated Chinese patients with hypertrophic cardiomyopathy. Am J Cardiol. 2013;112(4):585-9.

27. Kassem HS, Azer RS, Saber-Ayad M, Moharem-Elgamal S, Magdy G, Elguindy A, et al. Early results of sarcomeric gene screening from the Egyptian National BA-HCM Program. J Cardiovasc Transl Res. 2013;6(1):65-80.

28. Maron BJ, Kalra A. Hypertrophic cardiomyopathy in the developing world: focus on India. Eur Heart J. 2014;35(36):2492-5.

29. Adalsteinsdottir B, Teekakirikul P, Maron BJ, Burke MA, Gudbjartsson DF, Holm H, et al. Nationwide study on hypertrophic cardiomyopathy in Iceland: evidence of a MYBPC3 founder mutation. Circulation. 2014;130(14):1158-67.

30. Chiou KR, Chu CT, Charng MJ. Detection of mutations in symptomatic patients with hypertrophic cardiomyopathy in Taiwan. J Cardiol. 2015;65(3):250-6.

31. Moolman-Smook JC, De Lange WJ, Bruwer EC, Brink PA, Corfield VA. The origins of hypertrophic cardiomyopathy-causing mutations in two South African subpopulations: a unique profile of both independent and founder events. Am J Hum Genet. 1999;65(5):1308-20.

32. Ingles J, Semsarian C. The Australian genetic heart disease registry. Int J Cardiol. 2013;168(4):e127-8.

33. Marsiglia JD, Batitucci Mdo C, Paula Fd, Barbirato C, Arteaga E, Araújo AQ, et al. [Study of mutations causing hypertrophic cardiomyopathy in a group of patients from Espirito Santo, Brazil]. Arq Bras Cardiol. 2010;91(1):10-7.

34. Marsiglia JD, Credidio FL, de Oliveira TG, Reis RF, Antunes Mde O, de Araujo AQ, et al. Screening of MYH7, MYBPC3, and TNNT2 genes in Brazilian patients with hypertrophic cardiomyopathy. Am Heart J. 2013;166(4):775-82.

References

264

Original Article


Arq Bras Cardiol. 2016; 107(3):257-265

35. Giolo SR, Soler JM, Greenway SC, Almeida MA, de Andrade M, Seidman JG, et al. Brazilian urban population genetic structure reveals a high degree of admixture. Eur J Hum Genet. 2012;20(1):111-6.

36. Ruiz-Linares A, Adhikari K, Acuña-Alonzo V, Quinto-Sanchez M, Jaramillo C, Arias W, et al. Admixture in Latin America: geographic structure, phenotypic diversity and self-perception of ancestry based on 7,342 individuals. PLoS Genet. 2014;10(9):e1004572.

37. Miller SA, Dykes DD, Polesky HF. A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 1988;16(3):1215.

38. Cardiogenomics: Homepage. [Internet]. [Acesso em 2014 dez 20]. Disponível em http://www. http://cardiogenomica.altervista.org/

39. den Dunnen JT, Dalgleish R, Maglott DR, Hart RK, Greenblatt MS, McGowan-Jordan J, et al. HGVS recommendations for the description of sequence variants: 2016 update. Hum Mutat. 2016;37(6):564-9.

40. Adzhubei IA, Schmidt S, Peshkin L, Ramensky VE, Gerasimova A, Bork P, et al. A method and server for predicting damaging missense mutations. Nat Methods. 2010;7(4):248-9.

41. Kumar P, Henikoff S, Ng PC. Predicting the effects of coding non-synonymous variants on protein function using the SIFT algorithm. Nat Protoc. 2009;4(7):1073-81.

42. Choi Y, Sims GE, Murphy S, Miller JR, Chan AP. predicting the functional effect of amino acid substitutions and indels. PLoS One. 2012;7(10):e46688.

43. Schwarz JM, Cooper DN, Schuelke M, Seelow D. MutationTaster2: mutation prediction for the deep-sequencing age. Nat Methods. 2014;11(4):361-2.

44. Li B, Krishnan VG, Mort ME, Xin F, Kamati KK, Cooper DN, et al. Automated inference of molecular mechanisms of disease from amino acid substitutions. Bioinformatics. 2009;25(21):2744-50.

45. Hebsgaard SM, Korning PG, Tolstrup N, Engelbrecht J, Rouze P, Brunak S. Splice site prediction in Arabidopsis thaliana DNA by combining local and global sequence information. Nucleic Acids Res. 1996;24(17):3439-52.

46. Desmet FO, Hamroun D, Lalande M, Collod-Beroud G, Claustres M, Beroud C. Human Splicing Finder: an online bioinformatics tool to predict splicing signals. Nucleic Acids Res. 2009;37(9):e67.

47. Mattos BP, Torres MA, Freitas VC. Diagnostic evaluation of hypertrophic cardiomyopathy in its clinical and preclinical phases. Arq Bras Cardiol. 2008;91(1):51-62.

48. Lopes LR, Rahman MS, Elliott PM. A systematic review and meta-analysis of genotype-phenotype associations in patients with hypertrophic cardiomyopathy caused by sarcomeric protein mutations. Heart. 2013;99(24):1800-11.

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Relationship between Neck Circumference and Epicardial Fat Thickness in a Healthy Male PopulationUğur Küçük1, Hilal Olgun Küçük2, Ferhat Cüce3, Sevket Balta4

Gulhane Military Medical Academy Haydarpasa Training Hospital1, Department of Cardiology, İstanbul, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Center Training and Research Hospital2, Department of Cardiology, İstanbul, Van Army District Hospital3, Department of Radiology, Van, Gulhane Military Medical Academy Department of Cardiology4, Ankara – Turkey

Mailing Address: Uğur Küçük •Gulhane Military Medical Academy Haydarpasa Training Hospital, Department of Cardiology, İstanbul,34668 – TurkeyE-mail: [email protected] Manuscript received July 28, 2015; revised manuscript October 21, 2015; accepted February 29, 2016.

DOI: 10.5935/abc.20160112

AbstractBackground: Epicardial fat is an upper body visceral fat depot that may play a significant role in the development of adverse metabolic and cardiovascular risk profiles. There is a significant direct relationship between the amount of epicardial fat and general body adiposity (body mass index, BMI), but data regarding subcutaneous adiposity is limited.

Objective: We conducted a study to determine the association between neck circumference and epicardial fat thickness in healthy young male individuals, and assess their individual correlations with general body adiposity and cardiometabolic risk factors.

Methods: One hundred consecutive male patients aged 18 years or older with no known major medical conditions were included in the study. All participants underwent detailed physical examination including measurement of blood pressure, weight, height, waist/hip ratio, and neck circumference. Blood was collected to determine fasting glucose and lipid parameters. A standard echocardiographic examination was performed with additional epicardial fat thickness determination.

Results: Among 100 study participants, neck circumference correlated significantly with weight, waist circumference, BMI, blood glucose, serum total cholesterol, low-density (LDL)-cholesterol, and triglycerides levels. No significant correlation was found between neck circumference and high-density lipoprotein (HDL)-cholesterol levels. Neck circumference correlated moderately and positively with echocardiographic epicardial fat thickness.

Conclusion: Among patients with low cardiometabolic risk, increased neck circumference was associated with increased epicardial fat thickness. (Arq Bras Cardiol. 2016; 107(3):266-270)

Keywords: Neck; Intra-Abdominal Fat; Blood Pressure; Cardiovascular Diseases; Body Mass Index; Blood Glucose; Echocardiography / diagnosis.

artery and is further implicated in the pathogenesis of coronary artery disease.2,3

However, no studies have examined the association between neck circumference and epicardial fat. Thus, the goal of this analysis was to characterize the correlation between neck circumference and epicardial fat and answer the following specific question: is increased neck circumference associated with increased epicardial fat thickness in healthy male subjects with low cardiometabolic risk?

MethodWe recruited 100 consecutive male patients aged 18 years

or older without known major medical conditions (e.g., diabetes, coronary artery disease, hypertension, or thyroid or malignant diseases) and not receiving prescription medication. All subjects had attended annual periodic health examinations between November 2013 and May 2013. The participants were informed about the study procedures and agreed to participate providing written informed consent.

All measurements were performed by one investigator using the following standard techniques: weight, measured on a scale (Holtain, Wales) to the nearest 100 g with the participant wearing light clothing; height, measured

IntroductionDuring the past 20 years, numerous discoveries dramatically

changed our view of the adipose tissue from a simple storage depot to an active endocrine organ. In addition to its major role in lipid and glucose metabolism, the adipose tissue participates in the signaling of systemic homeostasis. The two major types of adipose tissue are visceral fat, localized within the abdominal cavity and mediastinum, and subcutaneous fat, localized in the hypodermis.

Neck circumference, a proxy for upper body subcutaneous fat, is a unique fat depot that confers additional cardiovascular risk above and beyond central body fat.1 Epicardial fat is an upper body visceral fat depot that may play a significant role in the development of adverse metabolic and cardiovascular risk profiles. It modulates local functions of the coronary

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with a portable stadiometer with the participant barefoot (Holtain, Wales) to the nearest 0.5 cm; and waist and hip circumferences, measured with weekly calibrated plastic tapes to the nearest 1 mm. The waist circumference was measured at the end of gentle expiration midway between the lowest rib and the iliac crest with the patient standing, while the hip circumference was measured at the greater trochanter.1 Body mass index (BMI) was calculated as weight in kilograms divided by the square of the height in meters. Neck circumference was measured to 1-mm accuracy with a plastic tape in a standardized manner, horizontally above the cricothyroid cartilage, just below the laryngeal prominence.4 All measurements were taken with the subjects standing upright, facing the investigator, and with shoulders relaxed.

Systolic and diastolic blood pressure was measured twice in all participants by the same physician using a standard aneroid sphygmomanometer on the right arm of the seated subject. The mean value for blood pressure measurements was adopted. After a 12-hour fasting, blood samples were collected for analyses of blood glucose, total cholesterol, HDL-cholesterol, and triglycerides. Epicardial fat was assessed via transthoracic echocardiography (ProSound 6, Hitachi-Aloka, Tokyo Japan). A standard echocardiographic examination was performed in all participants. Maximum epicardial fat thickness was measured from a two-dimensional long-axis view on the right ventricular free wall perpendicular to the aortic annulus or at a mid-chordal level from a parasternal short-axis view at the tip of the papillary muscle at end-systole. Average values of three cardiac cycles from each echocardiographic view were determined. Based on previous studies, the upper normal limit for epicardial fat thickness was determined as 7 mm.5

Statistical analysisContinuous variables are expressed as mean ± standard

deviation (SD). All statistical calculations were performed using SPSS 18 (SPSS Inc., Chicago, IL, USA). Normality was tested using the Kolmogorov-Smirnov test in addition to graphical methods (probability-probability plots and histograms). As both parameters were normally distributed, the correlation coefficients and their significance were calculated using Pearson test. Neck circumference and epicardial fat measurements were divided into five equal groups, and intraobserver variability was investigated using the Kappa test. A multiple regression model was used to identify independent predictors of epicardial fat thickness. The model fit was assessed using appropriate residual and goodness of fit statistics. A 5% type-I error level was used to infer statistical significance.

ResultsThe study sample consisted of 100 male individuals

with a mean age of 26.0 ± 4.3 years. None of the patients had documented major comorbidities. The mean BMI of the participants was 24.9 ± 3.5 kg/m2 and the mean neck circumference was 39.4 ± 2.39 cm (Table 1). In correlation analysis among all subjects, neck circumference correlated significantly with weight, waist circumference, and BMI, and moderately with serum total cholesterol, LDL-cholesterol,

and triglycerides levels. No significant correlation was found between neck circumference and HDL-cholesterol levels (Figure 1). Neck circumference correlated moderately and positively with echocardiographic epicardial fat thickness. A matrix scatter plot in the Figure demonstrates a linear association between neck circumference, epicardial fat, BMI, and LDL-cholesterol. We used multiple regression analysis to test if the neck circumference predicted significantly the epicardial fat thickness. The results indicated that neck circumference, BMI, and LDL-cholesterol explained 79% of the variance (R2 = 0.799, F[3,13] = 17.2, p < 0.01). We found that neck circumference significantly predicted epicardial fat thickness (β = 0.879, p < 0.001). We also observed a good intraobserver agreement for neck circumference and epicardial fat measurements (Kappa values = 0.723 and 0.715, respectively, p values = 0.574 and 0.974, respectively).

DiscussionThis study indicates a correlation between neck

circumference and epicardial fat thickness, as well as between neck circumference and other anthropometric measures in healthy, nonobese male individuals. Neck circumference also showed a strong correlation with serum total cholesterol, LDL-cholesterol, and triglyceride levels.

The distribution of body adiposity is a stronger predictor of metabolic dysfunction and cardiovascular risk than whole-body adiposity, which is measured with the BMI.6 The wide use of the waist circumference relies on its correspondence to abdominal visceral fat, which is thought to have a major role in cardiometabolic risk.7 Apart from waist circumference, other circumferences have also been evaluated as anthropometric indices, including neck, hip, thigh, arm, and calf circumferences. Among them, neck circumference is an alternative measure of upper body subcutaneous fat, which relates to cardiometabolic risk as much as abdominal visceral adipose tissue (VAT).8 Consistent with previous reports,9 this study showed that neck circumference correlated well with waist circumference, waist-to-hip ratio, and BMI. Compared with waist circumference, neck circumference is easier to measure and has low intra- and interobserver variability.10

In the Framingham Heart Study, neck circumference was associated with cardiometabolic risk factors even after adjustment for VAT.8 Similarly, we have shown a positive correlation between neck circumference, serum total cholesterol, LDL-cholesterol, and triglycerides levels. Based on these findings, some authors have suggested the use of neck circumference as a tool for identification of metabolic syndrome and insulin resistance.9 These correlations transform further into the clinical picture with numerous data reporting associations between clinical/subclinical atherosclerosis and neck circumference.11-13

Epicardial fat is located on the surface of the heart especially around the epicardial coronary vessels. It is the true visceral fat depot of the heart. Under normal physiological conditions, epicardial fat has several putative functions: it protects the heart against excessively high

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Table 1 – Association between neck circumference and clinical, laboratory and echocardiographic parameters

Correlation coefficients

Neck Circumference

Mean ± SD R* p

Altura, cm 175 ± 7.32 0.111 0.272

Peso, kg 76.7 ± 10.87 0.715 < 0.001

IMC, kg/m2 24.9 ± 3.50 0.673 < 0.001

Cintura, cm 90 ± 9.54 0.638 < 0.001

Quadril, cm 103 ± 7.2 0.191 0.06

Colesterol total, mg/dL 183 ± 35.86 0.435 < 0.001

Triglicerídeos, mg/dL 173 ± 54.9 0.338 < 0.001

LDL-colesterol, mg/dL 83.9 ± 25.84 0.432 0.014

HDL-colesterol, mg/dL 45.5 ± 9.59 0.201 0.271

Gordura epicárdica, mm 2.98 ± 1.26 0.474 < 0.001

SD: standard deviation; BMI: body mass index; LDL: low-density lipoprotein; HDL: high-density lipoprotein; R: Pearson correlation coefficient.

Figure 1 – Matrix scatterplot showing associations between neck circumference, epicardial fat, BMI, and LDL-cholesterol.

Neck

Ci

rcunfe

renc

eEp

icard

ial F

at

Epicardial Fat

BMI

BMI

LDL

LDLNeck Circunference

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circulating levels of fatty acids, acts as a local energy source at times of high demand channeling fatty acids to the myocardium, and buffers the coronary arteries against the torsion induced by the arterial pulse wave and cardiac contraction.14,15 Epicardial fat is also a source of several proinflammatory and proatherogenic cytokines, as well as tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-6, leptin, plasminogen activator inhibitor-1, and angiotensinogen.16,17 Epicardial fat also produces antiinflammatory and antiatherogenic adipokines, such as adiponectin and adrenomedullin.5,18 In general, epicardial fat exerts a protective modulation of vascular function and energy partition in a healthy situation, but when expanded, it turns into an adverse lipotoxic, prothrombotic, and proinflammatory organ.19,20

Epicardial fat thickness can be visualized and measured with two-dimensional echocardiography, magnetic resonance imaging, and/or computed tomography. On echocardiography, epicardial fat thickness clearly reflects visceral adiposity and increases with an increase in general adiposity. In hearts with markedly increased epicardial fat mass, epicardial fat thickness shows a highly significant correlation with body weight.21 Autopsy studies, however, report a weak correlation between BMI and epicardial fat. Several autopsy studies have evaluated the correlation between epicardial fat and subcutaneous adipose tissue. Womack et al. reported a significant correlation between epicardial fat and the total amount of fat in the calf in both sexes.22 Besides all above mentioned associations between various subcutaneous fat tissues and epicardial fat, there is a paucity of studies relating neck circumference to epicardial fat as a proxy of upper body subcutaneous adiposity. This is the first study demonstrating a significant correlation between neck circumference and epicardial fat thickness.

Considering that echocardiographic epicardial fat thickness correlates with metabolic syndrome, insulin resistance, coronary artery disease, and subclinical atherosclerosis, it might serve as a simple tool for cardiometabolic risk prediction.23-25 Substantial changes in echocardiographic epicardial fat thickness during weight loss may also suggest its use as a marker of therapeutic effect. However, the requirement of echocardiography to measure epicardial fat thickness limits its widespread use in clinical settings,

whereas measurement of neck circumference is a simple, low cost, and informative tool that every healthcare provider can utilize in assessing cardiometabolic risk and estimating epicardial fat thickness.

ConclusionNeck circumference was a reliable and feasible alternative

measurement that correlated well with other anthropometric measurements and cardiometabolic parameters. It is also strongly associated with epicardial fat thickness. We suggest neck circumference measurement to be used to estimate epicardial fat thickness during daily clinic practice.

LimitationsSince this study included only healthy young men, we are

unable to determine if the results could be applied to other populations including women and individuals with metabolic syndrome or other comorbidities. All measurements were performed by the same author, which makes the study prone to systematic error.

Author contributionsConception and design of the research:Küçük U.

Acquisition of data: Küçük U, Cüce F. Statistical analysis: Küçük U. Writing of the manuscript:Küçük HO. Critical revision of the manuscript for intellectual content: Küçük HO, Balta S. Supervision / as the major investigador: Küçük HO.


was reported.


Study AssociationThis study is not associated with any thesis or dissertation work.

1. Li HX, Zhang F, Zhao D, Xin Z, Guo SQ, Wang SM, et al. Neck circumference as a measure of neck fat and abdominal visceral fat in Chinese adults. BMC Public Health. 2014;14:311.

2. Gorter PM, de Vos AM, van der Graaf Y, Stella PR, Doevendans PA, Meijs MF, et al. Relation of epicardial and pericoronary fat to coronary atherosclerosis and coronary artery calcium in patients undergoing coronary angiography. Am J Cardiol. 2008;102(4):380-5.

3. Iacobellis G, Barbaro G. The double role of epicardial adipose tissue as pro- and anti-inflammatory organ. Horm Metab Res. 2008;40(7):442-5.

4. Yang GR, Yuan SY, Fu HJ, Wan G, Zhu LX, Bu XL, et al; Beijing Community Diabetes Study Group. Neck circumference positively related with central obesity, overweight, and metabolic syndrome in Chinese subjects with type 2 diabetes: Beijing Community Diabetes Study 4. Diabetes Care. 2010;33(11):2465-7.

5. Iacobellis G, Corradi D, Sharma AM. Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart. Nat Clin Pract Cardiovasc Med. 2005;2(10):536-43.

6. Cornier MA, Despres JP, Davis N, Grossniklaus DA, Klein S, Lamarche B, et al; American Heart Association Obesity Committee of the Council on

References

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Nutrition; Physical Activity and Metabolism; Council on Arteriosclerosis; Thrombosis and Vascular Biology; Council on Cardiovascular Disease in the Young; Council on Cardiovascular Radiology and Intervention; Council on Cardiovascular Nursing, Council on Epidemiology and Prevention; Council on the Kidney in Cardiovascular Disease, and Stroke Council. Assessing adiposity: a scientific statement from the American Heart Association. Circulation. 2011;124(18):1996-2019.

7. Preis SR, Massaro JM, Robins SJ, Hoffmann U, Vasan RS, Irlbeck T, et al. Abdominal subcutaneous and visceral adipose tissue and insulin resistance in the Framingham heart study. Obesity (Silver Spring). 2010;18(11):2191-8.

8. Preis SR, Massaro JM, Hoffmann U, D’Agostino RB Sr, Levy D, Robins SJ, et al. Neck circumference as a novel measure of cardiometabolic risk: the Framingham Heart study. J Clin Endocrinol Metab. 2010;95(8):3701-10.

9. Stabe C, Vasques AC, Lima MM, Tambascia MA, Pareja JC, Yamanaka A, et al. Neck circumference as a simple tool for identifying the metabolic syndrome and insulin resistance: results from the Brazilian Metabolic Syndrome Study. Clin Endocrinol (Oxf). 2013;78(6):874-81.

10. LaBerge RC, Vaccani JP, Gow RM, Gaboury I, Hoey L, Katz SL. Inter- and intra-rater reliability of neck circumference measurements in children. Pediatric Pulmonol. 2009;44(1):64-9.

11. Zen V, Fuchs FD, Wainstein MV, Gonçalves SC, Biavatti K, Riedner CE, et al. Neck circumference and central obesity are independent predictors of coronary artery disease in patients undergoing coronary angiography. Am J Cardiovasc Dis. 2012;2(4):323-30.

12. Medeiros CA, Bruin VM, Castro-Silva C, Araujo SM, Chaves Junior CM, Bruin PF. Neck circumference, a bedside clinical feature related to mortality of acute ischemic stroke. Rev Assoc Med Bras. 2011;57(5):559-64.

13. Fitch KV, Stanley TL, Looby SE, Rope AM, Grinspoon SK. Relationship between neck circumference and cardiometabolic parameters in HIV-infected and non-HIV-infected adults. Diabetes Care. 2011;34(4):1026-31.

14. Marchington JM, Mattacks CA, Pond CM. Adipose tissue in the mammalian heart and pericardium: structure, foetal development and biochemical properties. Comp Biochem Physiol B. 1989;94(2):225-32.

15. Rabkin SW. Epicardial fat: properties, function and relationship to obesity. Obes Rev. 2007;8(3):253-61.

16. Mazurek T, Zhang L, Zalewski A, Mannion JD, Diehl JT, Arafat H, et al. Human epicardial adipose tissue is a source of inflammatory mediators. Circulation. 2003;108(20):2460-6.

17. Cheng KH, Chu CS, Lee KT, Lin TH, Hsieh CC, Chiu CC, et al. Adipocytokines and proinflammatory mediators from abdominal and epicardial adipose tissue in patients with coronary artery disease. Int J Obes (Lond). 2008;32(2):268-74.

18. Silaghi A, Achard V, Paulmyer-Lacroix O, Scridon T, Tassistro V, Duncea I, et al. Expression of adrenomedullin in human epicardial adipose tissue: role of coronary status. Am J Physiol Endocrinol Metab. 2007;293(5):E1443-50.

19. Iozzo P. Myocardial, perivascular, and epicardial fat. Diabetes Care. 2011;34 Suppl 2:S371-9.

20. Wronska A, Kmiec Z. Structural and biochemical characteristics of various white adipose tissue depots. Acta Physiol (Oxf). 2012;205(2):194-208.

21. Shirani J, Berezowski K, Roberts WC. Quantitative measurement of normal and excessive (cor adiposum) subepicardial adipose tissue, its clinical significance, and its effect on electrocardiographic QRS voltage. Am J Cardiol. 1995;76(5):414-8.

22. Womack HC. The relationship between human body weight, subcutaneous fat, heart weight, and epicardial fat. Hum Biol. 1983;55(3):667-76.

23. Iacobellis G, Willens HJ. Echocardiographic epicardial fat: a review of research and clinical applications. J Am Soc Echocardiogr. 2009;22(12):1311-9.

24. Iacobellis G, Sharma AM. Epicardial adipose tissue as new cardio-metabolic risk marker and potential therapeutic target in the metabolic syndrome. Curr Pharm Des. 2007;13(21):2180-4.

25. Kim BJ, Kim BS, Kang JH. Echocardiographic epicardial fat thickness is associated with coronary artery calcification - results from the CAESAR study. Circ J. 2015;79(4):818-24.

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Review Article

Cardiac Regeneration using Growth Factors: Advances and ChallengesJuliana de Souza Rebouças1, Nereide Stela Santos-Magalhães1, Fabio Rocha Formiga2,3

Laboratório de Imunopatologia Keizo-Asami1 – Universidade Federal de Pernambuco (UFPE); Programa de Pós-Graduação em Biologia Celular e Molecular Aplicada2 – Universidade de Pernambuco (UPE), Recife, PE; Curso de Pós-Graduação em Patologia (UFBA/FIOCRUZ)3 – Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ), Salvador, BA – Brazil

KeywordsMyocardial Infarction; Myocardial Ischemia; Vascular

Remodeling; Intercellular Signaling Peptides and Proteins; Cell-and Tissue Based Therapy.Mailing Address: Fabio Rocha Formiga •Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz (FIOCRUZ). Rua Waldemar Falcão, 121, Candeal. Postal Code 40296710, Salvador, BA – Brazil.E-mail: [email protected] received October 31, 2015; revised manuscript March 18, 2016; accepted March 23, 2016.

DOI: 10.5935/abc.20160097

AbstractMyocardial infarction is the most significant manifestation

of ischemic heart disease and is associated with high morbidity and mortality. Novel strategies targeting at regenerating the injured myocardium have been investigated, including gene therapy, cell therapy, and the use of growth factors. Growth factor therapy has aroused interest in cardiovascular medicine because of the regeneration mechanisms induced by these biomolecules, including angiogenesis, extracellular matrix remodeling, cardiomyocyte proliferation, stem-cell recruitment, and others. Together, these mechanisms promote myocardial repair and improvement of the cardiac function. This review aims to address the strategic role of growth factor therapy in cardiac regeneration, considering its innovative and multifactorial character in myocardial repair after ischemic injury. Different issues will be discussed, with emphasis on the regeneration mechanisms as a potential therapeutic resource mediated by growth factors, and the challenges to make these proteins therapeutically viable in the field of cardiology and regenerative medicine.

IntroductionCardiovascular diseases (CVD) are the leading cause

of death among men and women worldwide, in all racial and ethnic groups.1 In the United States, these diseases account for approximately 57% of all deaths in the country.2 In Europe, CVD cause 4.3 million deaths every year, which represents almost half (48%) of all deaths in that continent.3 CVD are also the major death cause in Brazil, with a specific mortality rate for ischemic heart diseases of 53.8 deaths for every 100,000 inhabitants.4

In the CVD group, coronary artery disease (CAD) and peripheral artery disease (PAD) are significant causes of morbidity and mortality, requiring surgical bypass procedure or angioplasty for thousands of patients. On the other hand, myocardial infarction (MI) is the most important manifestation of ischemic heart disease and is also associated with high

morbidity and mortality. Ischemia is responsible for cardiac muscle damage, including the loss of cardiomyocytes. This process leads to a negative cardiac remodeling causing the cardiac tissue with a normal contractile function to be replaced by a non-functional scar tissue. The myocardium then produces a compensatory hypertrophic mechanism against ischemia-induced wound healing. However, the hypertrophy may make the heart susceptible to the onset of arrhythmias, ventricular fibrillation and massive heart attack.5,6 Although advanced revascularization procedures (angioplasty, catheterization, bypass) have contributed to a marked reduction in mortality for CVD, a significant number of patients are not eligible to these procedures or achieve incomplete revascularization with these interventions. Consequently, many of these patients show persistent symptoms of cardiac ischemia despite intensive medical care. They probably suffer from severe diffuse atherosclerotic disease, which cannot be treated by surgery or angioplasty. Symptomatic obstructive vascular disease leads to claudication, peripheral ischemia, angina and congestive heart failure, significantly limiting the quality of life of these patients.

Treatment of MI includes the use of drugs (antiplatelet agents, oral anticoagulants, nitrates, β-adrenergic blockers, ACE inhibitors, and others), surgical reperfusion and revascularization procedures, and, in more complex cases, heart transplantation. In the past decade, there was growing investigation on new strategies for regeneration of the injured myocardium, including gene therapy,7,8 cell therapy,9,10 and the use of growth factors.11 The later has also been investigated for the induction of therapeutic angiogenesis for peripheral arterial disease.12

The use of growth factors has aroused interest in cardiovascular medicine because of the direct action of these factors on several cell functions such as adhesion, proliferation, migration, and others. When obstruction of the coronary artery flow occurs, induction of angiogenesis by growth factors represents an important mechanism of myocardial repair and protection under hypoxic conditions, resulting in the formation of new vessels.13 Consequently, tissue perfusion increases, ultimately leading to a better cardiac function.

On the other hand, the regenerative potential of growth factors has gained great importance in the context of cell therapy. Studies have demonstrated that the benefits derived from the administration of stem cells in the infarct area result, to a greater extent, from the paracrine effect of the growth factors secreted by the cells implanted than from the direct action of the cells in the infarct tissue.9,14-16 These factors show the potential of inducing different regeneration mechanisms: positive remodeling of the extracellular matrix, proliferation of adult cardiomyocytes, recruiting/homing of cardiac stem cells, antiapoptotic and/or angiogenic effect.11,17 Together, these mechanisms may reduce

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Arq Bras Cardiol. 2016; 107(3):271-275

inflammation, fibrosis and inadequate perfusion of the ischemic myocardium, promoting tissue repair and improvement of the cardiac function.9

Despite the mechanisms of growth-factor-induced tissue regeneration, the therapeutic potential of these proteins is limited by their short biological half-life, low plasma stability and low specificity to target organs. In fact, Hwang and Kloner administered a cocktail of growth factors in rats intraperitoneally and did not observe benefits in the cardiac function, reduction of the infarct size or increase in vascularization.18

Thus, the clinical use of growth factors depends on new formulation technologies able to increase their half-lives, keep their bioactivity, and control their local delivery in target tissues. In this context, micro- and nanostructured systems have been used as delivery platforms,19,20 and are a promising formulation strategy for the therapeutic use of growth factors for cardiac regeneration.11

The objective of this review is to address the strategic role of growth factor therapy for cardiac regeneration, considering its innovative and multifactorial character on cardiac repair after an ischemic injury.

Mechanisms of cardiac regenerationThe innate capacity of the human heart for self-regeneration

is not enough to compensate the loss of cardiac muscle after an ischemic injury.9 Unlike what is observed with skeletal muscles, in which satellite cells and myoblasts form new myocytes a few days after an injury, cardiomyocytes from the border zone of the infarct rarely divide after an ischemic event.21 In a lesion induced by infarct, the heart loses approximately 50 g of muscle, and this can result in the death of 2 billion cardiomyocytes.22,23 This myocardial aggression triggers and modulates tissue reparative changes, including dilatation, hypertrophy, and formation of a collagen scar.24 In relation to cell renewal, the mechanisms of endogenous repair are not enough to induce significant renewal of the muscle mass lost after the ischemic injury.

Cardiomyocyte proliferation plays a key role in cardiac regeneration in some vertebrates, but the proliferative capacity of these cells is limited in the adult hearts of mammals.21 Another potential cell renewal mechanism is the mobilization of progenitor cells from the bone marrow to the ischemic area and their differentiation into functional cardiomyocytes.9 However, mobilization and homing of these progenitors are also not enough to induce significant regeneration. The myocardium also shelters a population of resident cardiac stem cells (CSC) with potential to differentiate into cardiomyocytes.25,26 The CSC seem to account for the baseline turnover of cardiomyocytes. However, this renewal probably occurs at very low rates in the absence of lesion.27

The efficacy of these endogenous mechanisms of tissue repair is limited by the hostile microenvironment of the infarcted myocardium, which is characterized by ischemia, inflammation, fibrosis and inadequate angiogenesis. This microenvironment probably prevents, the CSC activation. On the other hand, excessive inflammation also prevents progenitors mobilization and homing. The formation of fibrotic tissue is necessary to

prevent muscle rupture after infarction, but the high level of fibrosis represents an important physical barrier to myocardial cell regeneration.9 Therefore, mitigation of this hostile environment should contribute to cardiac repair, especially the reduction of local inflammation, apoptosis and fibrosis, as well as the increase in vascularization in the infarct and peri-infarct areas.

Growth factors inducing regenerative mechanismsAngiogenesis refers to the development of blood vessels

from a pre-existing vascular bed. From the medical point of view, the objective is to stimulate vessel growth in patients with conditions characterized by insufficient blood flow, such as ischemic heart diseases and peripheral vascular diseases.28

As regards the latter aspect, the identification of growth factors that induce the angiogenic process stimulated the interest in the use of these proteins for the induction of therapeutic angiogenesis.11 In the case of myocardial infarction, angiogenic therapy with growth factors may salvage the ischemic tissue at early stages of infarction, by supplying the tissue with new vessels. This process is essential to prevent heart failure through the control of cardiomyocyte hypertrophy and contractility.29 In fact, angiogenesis is the main growth factor-induced reparative mechanism and has been the mechanism most often investigated in experimental studies and clinical trials on injured myocardium repair. Most of these studies have dedicated their efforts toward the angiogenic and regenerative potential of vascular endothelial growth factor (VEGF)30-33 and fibroblast growth factor (FGF).31,34-36

Mitigation of the ischemic injury in the cardiac tissue may be induced by antiapoptotic factors, which exert potentially cardioprotective effects. Hepatocyte growth factor (HGF) was first identified as a hepatocyte mitogen, with chemotactic and antiapoptotic actions in different cell types.37 In rats undergoing ischemia and reperfusion, intravenous administration of HGF reduced apoptosis in cardiomyocytes and the infarct size.38 Other antiapoptotic factors with therapeutic potential in cardiac regeneration include platelet-derived growth factor (PDGF-BB)39 and protein thymosin β440, IL-1141, IL-3342, and others.

Endogenous mechanisms mediated by progenitors and stem cells include mobilization and homing of bone marrow progenitors as well as CSC activation. These cells may differentiate into new cardiomyocytes after the ischemic injury, but their number is reduced or they are insufficiently activated to produce significant muscular regeneration. Some proteins show the potential to mobilize bone marrow progenitors to the cardiac lesion area or activate CSC. These properties may be therapeutically explored as regenerative mechanisms activated by growth factors or recombinant proteins, such as the granulocyte colony stimulating factor (G-CSF),43 HGF,44 stromal cell-derived factor (SDF-1),45 and others.

The paradigm of the heart as a completely differentiated organ was contested based on the identification of mitogens able to induce adult cardiomyocytes to enter into the cell cycle.46,47 This process opens the possibility to stimulate a new regeneration mechanism in the infarcted heart, leading to the formation of a population of new

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Table 1 – Main growth factors inducing the mechanisms of cardiac regeneration

Factor Mechanisms Reference

VEGF Angiogenesis 30-33

FGF Angiogenesis 31,34-36

HGFAntiapoptosis

37,38, 44CSCs chemotaxis

SDF-1 Hematopoietic stem cells mobilization and homing 45

IGF-1 Stem cells and progenitor cells viability and differentiation 52

PDGF Antiapoptosis 39

G-CSFAntiapoptosis

43Hematopoietic stem cells mobilization and homing

Intermedin Angiogenesis 53

Angiopoietin Angiogenesis, remodeling and vascular stabilization 54

Periostin Cardiomyocyte proliferation 49

Neuregulin-1 Cardiomyocyte proliferation 47

Erythropoietin Antiapoptosis 55

VEGF: vascular endothelium growth factor isoforms; FGF: fibroblast growth factor; HGF: Hepatocyte growth factor; SDF-1: stromal cell-derived factor; IGF-1: Insulin-like growth factor 1; PDGF: platelet-derived growth factor; G-CSF: granulocyte colony stimulating factor.

cardiomyocytes capable of replacing the cell mass lost due to the ischemic injury. Three extracellular factors have been identified for their ability to activate receptors involved in cardiomyocyte proliferation: acidic fibroblast growth factor (FGF-1),48 neuregulin (NRG-1),47 and periostin.49 Treatment of infarcted rats with FGF-1 in combination with a mitogen-activating protein kinase (MAPK) p38 resulted in increased cardiomyocyte mitosis and improved cardiac function.50 Studies have demonstrated improved cardiac function in infarcted mice treated with daily injections of NRG-1.47,51 A summary of growth factor-induced cardiac regeneration mechanisms is shown in Table 1.

Challenges in growth factor formulationIn the past two decades, intensive research on the

mechanisms of cardiac regeneration has resulted in considerable advances in the discovery of therapeutic targets related to several growth factors. These proteins have been evaluated in experimental studies and clinical trials, which have demonstrated the safety and potential efficacy of these factors in the treatment of ischemic heart diseases, particularly myocardial infarction.11,56 However, an important challenge for establishing protein therapy for these diseases is the development of formulation technologies capable of ensuring the reparative mechanisms of these biomolecules and making them clinically viable.

Aspects related to dosage, route of administration, protein stability and biocompatibility should be considered. The ability of these formulations to incorporate multiple factors also represents a critical issue, considering the multifactorial character of the mechanisms involved in myocardial repair following ischemia. Together, these aspects have been previously reviewed and should guide the rational development of growth factor formulations for protein and/or cell therapy focusing on cardiac generation.11

Micro- and nanostructured controlled delivery systems show several advantages over conventional formulations that deliver biopharmaceuticals in their free form, usually in an aqueous vehicle for intravenous administration. By permitting a more adequate pharmacokinetic profile to the effects of the active compound, micro- and nanoformulations facilitate patient’s adherence to treatment; provide protection to the active ingredient against enzymatic degradation; permit specific targeting to an organ or target-structure; local and controlled delivery of the molecule of interest. Polymeric systems (hydrogels, scaffolds, micro- and nanoparticles)11,57,58 and lipid systems (liposomes, solid lipid nanoparticles)59,60 have been used as cardiac delivery platforms of growth factors, which can be obtained from natural biomaterials (collagen/gelatin, fibrin, hyaluronic acid, alginate, chitosan, etc.) and synthetic materials (polyesters, amino acid polymers, polyacrylamide derivatives, and others).11

Polyesters such as poly (lactic acid-co-glycolic acid, PLGA) and polycaprolactone (PCL) are polymers approved for the use in drug delivery systems because of their low immunogenic potential and adequate biodegradation profile. Previous studies have demonstrated the biocompatibility of PLGA microparticles with the cardiac tissue and the efficacy of these particles as delivery systems of VEGF in the experimental treatment of myocardial infarction.58,61 Recently, Formiga and colleagues have demonstrated the efficacy of these microparticles as cardiac delivery systems of FGF-1 and NRG-1, ensuring the regenerative effects of these factors in an rat myocardial infarction model.62

PerspectivesFuture perspectives for the use of cardioregenerative

factors are related to the development of new formulation

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1. Mathers CD, Loncar D. Projections of global mortality and burden of disease from 2002 to 2030. PLoS Med. 2006;3(11):e442.

2. Rosamond W, Flegal K, Furuie K, Greenlund K, Haase V, Ho M, et al. Heart disease and stroke statistics-2008 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2008;117(4):e25-146.

3. British Heart Foundation. European Cardiovascular Disease Statistics 2008. [Accessed in 2015 Nov 12]. Available from: https://www.bhf.org.uk/publications/statistics/european_cardiovascular_disease_statistics_2008.

4. Ministério da Saúde Datasus 2011. Sistema de informações de mortalidade. [Acesso em 2015 Dez 13]. Disponível em: http://tabnet.datasus.gov.br/cgi/tabcgi.exe?idb2012/c08.def.

5. Jugdutt BI. Ischemia/infarction. Heart Fail Clin. 2012;8(1):43-51.

6. Zornoff LA, Paiva SA, Duarte DR, Spadaro J. Ventricular remodeling after myocardial infarction: concepts and clinical implications. Arq Bras Cardiol. 2009;92(2):150-6.

7. Gaffney MM, Hynes SO, Barry F, O’Brien T. Cardiovascular gene therapy: current status and therapeutic potential. Br J Pharmacol. 2007;152(2):175-88.

8. Scimia MC, Gumpert AM, Koch WJ. Cardiovascular gene therapy for myocardial infarction. Expert Opin Biol Ther. 2014;14(2):183-95.

9. Segers VF, Lee RT. Stem-cell therapy for cardiac disease. Nature. 2008;451(7181):937-42.

10. Souza CF, Napoli P, Han SW, Lima VC, Carvalho AC. Células-tronco mesenquimais: células ideais para a regeneração cardíaca? Rev Bras Cardiol Invasiva [on-line]. 2010;18(3):344-53.

11. Formiga FR, Tamayo E, Simon-Yarza T, Pelacho B, Prosper F, Blanco-Prieto MJ. Angiogenic therapy for cardiac repair based on protein delivery systems. Heart Fail Rev. 2012;17(3):449-73.

12. Annex BH. Therapeutic angiogenesis for critical limb ischaemia. Nat Rev Cardiol. 2013;10(7):387-96.

13. Lee SH, Wolf PL, Escudero R, Deutsch R, Jamieson SW, Thistlethwaite PA. Early expression of angiogenesis factors in acute myocardial ischemia and infarction. N Engl J Med. 2000;342(9):626-33.

14. Gnecchi M, Zhang Z, Ni A, Dzau VJ. Paracrine mechanisms in adult stem cell signaling and therapy. Circ Res. 2008;103(11):1204-19.

15. Feng Y, Wang Y, Cao N, Yang H. Progenitor/stem cell transplantation for repair of myocardial infarction: Hype or hope? Ann Palliat Med. 2012;1(1):65-77.

16. Mirotsou M, Jayawardena TM, Schmeckpeper J, Gnecchi M, Dzau VJ. Paracrine mechanisms of stem cell reparative and regenerative actions in the heart. J Mol Cell Cardiol. 2011;50(2):280-9.

17. Patel AN, Silva F, Winters AA. Stem cell therapy for heart failure. Heart Fail Clin. 2015;11(2):275-86.

18. Hwang H, Kloner RA. The combined administration of multiple soluble factors in the repair of chronically infarcted rat myocardium. J Cardiovasc Pharmacol. 2011;57(3):282-6.

19. Vilos C, Velasquez LA. Therapeutic strategies based on polymeric microparticles. J Biomed Biotechnol. 2012;2012:672760.

20. Mundargi RC, Babu VR, Rangaswamy V, Patel P, Aminabhavi TM. Nano/micro technologies for delivering macromolecular therapeutics using poly(D,L-lactide-co-glycolide) and its derivatives. J Control Release. 2008;125(3):193-209.

21. Ahuja P, Sdek P, MacLellan WR. Cardiac myocyte cell cycle control in development, disease, and regeneration. Physiol Rev. 2007;87(2):521-44.

22. Gepstein L. Derivation and potential applications of human embryonic stem cells. Circ Res 2002;91(10):866-76.

23. Venugopal JR, Prabhakaran MP, Mukherjee S, Ravichandran R, Dan K, Ramakrishna S. Biomaterial strategies for alleviation of myocardial infarction. J R Soc Interface. 2012;9(66):1-19.

24. Sutton MG, Sharpe N. Left ventricular remodeling after myocardial infarction: pathophysiology and therapy. Circulation. 2000;101(25):2981-8.

25. Beltrami AP, Barlucchi L, Torella D, Baker M, Limana F, Chimenti S, et al. Adult cardiac stem cells are multipotent and support myocardial regeneration. Cell. 2003;114(6):763-76.

26. Mayfield AE, Tilokee EL, Davis DR. Resident cardiac stem cells and their role in stem cell therapies for myocardial repair. Can J Cardiol. 2014;30(11):1288-98.

27. Hsieh PC, Segers VF, Davis ME, Macgillivray C, Gannon J, Molkentin JD, et al. Evidence from a genetic fate-mapping study that stem cells refresh adult mammalian cardiomyocytes after injury. Nat Med. 2007;13(8):970-4.

References

technologies combined with smart, biocompatible, non-invasive materials. These advances should work as multifunctional structures that combine therapeutic and diagnostic functions in a single micro- or nanostructurated. Additionally, they will allow specific ligand-guided targeting on the material surface. The translational potential of these technologies is predictable, considering the diversity of growth factor-induced regeneration mechanisms. These processes should be explored with more clinical interest both as protein therapy and as adjuvant in stem-cell therapy for cardiac regeneration.

Author contributionsConception and design of the research and Critical revision

of the manuscript for intellectual content: Rebouças JS, Santos-

Magalhães NS, Formiga FR; Acquisition of data: Rebouças JS, Formiga FR; Analysis and interpretation of the data and Writing of the manuscript: Rebouças JS, Formiga FR; Obtaining financing: Santos-Magalhães NS, Formiga FR.



Sources of Funding

This study was partially funded by CNPq (461865/2014-9).

Study Association


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28. Ng YS, D’Amore PA. Therapeutic angiogenesis for cardiovascular disease. Curr Control Trials Cardiovasc Med. 2001;2(6):278-85.

29. Cochain C, Channon KM, Silvestre JS. Angiogenesis in the infarcted myocardium. Antioxid Redox Signal. 2013;18(9):1100-13.

30. Taimeh Z, Loughran J, Birks EJ, Bolli R. Vascular endothelial growth factor in heart failure. Nat Rev Cardiol. 2013;10(9):519-30.

31. Atluri P, Woo YJ. Pro-angiogenic cytokines as cardiovascular therapeutics: assessing the potential. BioDrugs. 2008;22(4):209-22.

32. Testa U, Pannitteri G, Condorelli GL. Vascular endothelial growth factors in cardiovascular medicine. J Cardiovasc Med (Hagerstown). 2008;9(12):1190-221.

33. Henry TD, Annex BH, McKendall GR, Azrin MA, Lopez JJ, Giordano FJ, et al; VIVA Investigators. The VIVA trial: Vascular endothelial growth factor in Ischemia for Vascular Angiogenesis. Circulation. 2003;107(10):1359-65.

34. Zhang J, Li Y. Therapeutic uses of FGFs. Semin Cell Dev Biol. 2015 Sept 11 [Epub ahead of print].

35. Unger EF, Goncalves L, Epstein SE, Chew EY, Trapnell CB, Cannon RO 3rd, et al. Effects of a single intracoronary injection of basic fibroblast growth factor in stable angina pectoris. Am J Cardiol. 2000;85(12):1414-9.

36. Simons M, Annex BH, Laham RJ, Kleiman N, Henry T, Dauerman H, et al. Pharmacological treatment of coronary artery disease with recombinant fibroblast growth factor-2: double-blind, randomized, controlled clinical trial. Circulation. 2002;105(7):788-93.

37. Boros P, Miller CM. Hepatocyte growth factor: a multifunctional cytokine. Lancet. 1995;345(8945):293-5.

38. Nakamura T, Mizuno S, Matsumoto K, Sawa Y, Matsuda H. Myocardial protection from ischemia/reperfusion injury by endogenous and exogenous HGF. J Clin Invest. 2000;106(12):1511-9.

39. Hsieh PC, Davis ME, Gannon J, MacGillivray C, Lee RT. Controlled delivery of PDGF-BB for myocardial protection using injectable self-assembling peptide nanofibers. J Clin Invest. 2006;116(1):237-48.

40. Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-72.

41. Obana M, Maeda M, Takeda K, Hayama A, Mohri T, Yamashita T, et al. Therapeutic activation of signal transducer and activator of transcription 3 by interleukin-11 ameliorates cardiac fibrosis after myocardial infarction. Circulation. 2010;121(5):684-91.

42. Seki K, Sanada S, Kudinova AY, Steinhauser ML, Handa V, Gannon J, et al. Interleukin-33 prevents apoptosis and improves survival after experimental myocardial infarction through ST2 signaling. Circ Heart Fail. 2009;2(6):684-91.

43. Huber BC, Beetz NL, Laskowski A, Ziegler T, Grabmaier U, Kupatt C, et al. Attenuation of cardiac hypertrophy by G-CSF is associated with enhanced migration of bone marrow-derived cells. J Cell Mol Med 2015;19(5):1033-41.

44. Madonna R, Cevik C, Nasser M, De Caterina R. Hepatocyte growth factor: molecular biomarker and player in cardioprotection and cardiovascular regeneration. Thromb Haemost. 2012;107(4):656-61.

45. Shao S, Cai W, Sheng J, Yin L. Role of SDF-1 and Wnt signaling pathway in the myocardial fibrosis of hypertensive rats. Am J Transl Res. 2015;7(8):1345-56.

46. Bergmann O, Bhardwaj RD, Bernard S, Zdunek S, Barnabe-Heider F, Walsh S, et al. Evidence for cardiomyocyte renewal in humans. Science. 2009;324(5923):98-102.

47. Bersell K, Arab S, Haring B, Kuhn B. Neuregulin1/ErbB4 signaling induces cardiomyocyte proliferation and repair of heart injury. Cell. 2009;138(2):257-70.

48. Engel FB, Schebesta M, Duong MT, Lu G, Ren S, Madwed JB, et al. p38 MAP kinase inhibition enables proliferation of adult mammalian cardiomyocytes. Genes Dev. 2005;19(10):1175-87.

49. Kuhn B, Del Monte F, Hajjar RJ, Chang YS, Lebeche D, Arab S, et al. Periostin induces proliferation of differentiated cardiomyocytes and promotes cardiac repair. Nat Med. 2007;13(8):962-9.

50. Engel FB, Hsieh PC, Lee RT, Keating MT. FGF1/p38 MAP kinase inhibitor therapy induces cardiomyocyte mitosis, reduces scarring, and rescues function after myocardial infarction. Proc Natl Acad Sci USA. 2006;103(42):15546-51.

51. Liu X, Gu X, Li Z, Li X, Li H, Chang J, et al. Neuregulin-1/erbB-activation improves cardiac function and survival in models of ischemic, dilated, and viral cardiomyopathy. J Am Coll Cardiol. 2006;48(7):1438-47.

52. Dai W, Kloner RA. Cardioprotection of insulin-like growth factor-1 during reperfusion therapy: what is the underlying mechanism or mechanisms? Circ Cardiovasc Interv. 2011;4(4):311-3.

53. Holmes D, Campbell M, Harbinson M, Bell D. Protective effects of intermedin on cardiovascular, pulmonary and renal diseases: comparison with adrenomedullin and CGRP. Curr Protein Pept Sci. 2013;14(4):294-329.

54. Chong AY, Caine GJ, Lip GY. Angiopoietin/tie 2 as mediators of angiogenesis: a role in congestive heart failure. Eur J Clin Investig. 2004;34(1):9-13.

55. Calvillo L, Latini R, Kajstura J, Leri A, Anversa P, Ghezzi P, Et al. Recombinant human erythropoietin protects the myocardium from ischemia-reperfusion injury and promotes beneficial remodeling. Proc Natl Acad Sci USA. 2003;100(8):4802-6.

56. Simon-Yarza T, Formiga F, Tamayo E, Pelacho B, Prosper F, Blanco-Prieto M. Vascular endothelial growth factor-delivery systems for cardiac repair: an overview. Theranostics. 2012;2(6):541-52.

57. Rocha Formiga F, Ansorena E, Estella-Hermoso de Mendoza A, Imbuluzqueta E, González D, Blanco-Prieto MJ. Nanosistemas a base de poliésteres. In: Vila Jato JL. (ed). Nanotecnología farmacéutica. Madrid: Real Academia Nacional de Farmacia; 2009. p. 41-101.

58. Formiga FR, Pelacho B, Garbayo E, Abizanda G, Gavira JJ, Simon-Yarza T, et al. Sustained release of VEGF through PLGA microparticles improves vasculogenesis and tissue remodeling in an acute myocardial ischemia-reperfusion model. J Control Release. 2010;147(1):30-7.

59. Scott RC, Rosano JM, Ivanov Z, Wang B, Chong PL, Issekutz AC, et al. Targeting VEGF-encapsulated immunoliposomes to MI heart improves vascularity and cardiac function. FASEB J. 2009;23(10):3361-7.

60. Zhang S, Uludağ H. Nanoparticulate systems for growth factor delivery. Pharm Res. 2009;26(7):1561-80.

61. Formiga F, Garbayo E, Diaz-Herraez P, Abizanda G, Simon-Yarza T, Tamayo E, et al. Biodegradation and heart retention of polymeric microparticles in a rat model of myocardial ischemia. Eur J Pharm Biopharm. 2013;85(3):665-72.

62. Formiga FR, Pelacho B, Garbayo E, Imbuluzqueta I, Diaz-Herraez P, Abizanda G, et al. Controlled delivery of fibloblast growth factor-1 and neuregulin-1 from biodegradable microparticles promotes cardiac repair in a rat myocardial infarction model through activation of endogenous regeneration. J Control Release. 2014;173:132-9.

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Case 5/2016 – Native Coarctation of the Aortic Arch, Relieved By Percutaneous Treatment in an AdultEdmar Atik and Raul ArrietaClínica privada Dr. Edmar Atik, São Paulo, SP – Brazil

KeywordsAortic Disease; Aortic Disease/complications; Cardiac

Hypertrophy; Angioplasty; Hypertension.

Clinical data: the patient had a good clinical course after repair of severe coarctation of the aortic isthmus with end‑to‑end technique, closure of the interventricular communication at 18 days of life, and relief of moderate subaortic stenosis at 3 years of age. Currently, the patient can tolerate well routine exercise, with no symptoms. At last evaluation, blood pressure in the right arm was 140/70 mmHg and the systolic pressure in the left arm and lower limbs was 90 mmHg, suggesting aortic arch obstruction. Previous evaluations have shown a pressure gradient of 15 mmHg between the upper limbs.

Physical examination: good general health, normal breathing, acyanotic, unequal pulse between the right upper arm and lower extremities. Weight: 65 Kg, height: 165 cm, right upper arm arterial pressure: 140/70 mmHg, left upper arm arterial pressure: 115/80 mmHg, right lower limb arterial pressure: 105/80 mmHg, and heart rate: 82 bpm. The aorta was palpable in the supra‑sternal notch, with fremitus and systolic murmur (grade 2).

In the precordium, the apex beat was not palpable and no impulse was detected during systole. Heart sounds were normal, and a harsh, grade 2 systolic murmur was heard in the aortic area and left sternal border with fremitus. The liver was not palpable.

Complementary testsElectrocardiogram showed sinus rhythm, signs of

complete right bundle branch block wit QRS duration of 0.14’’, and block of the anterior superior division of the left bundle branch (unchanged since neonatal aortic coarctation repair and interventricular communication). P axis: +20o, QRS axis: +250o, T axis: +35o.

Chest radiograph showed normal heart area and myocardial hypertrophy, and normal pulmonary vasculature.

Echocardiogram showed normal‑sized cardiac chambers, mild myocardial hypertrophy (septum = 14 mm and posterior

wall = 11 mm), pressure gradient across the aortic arch = 61 mmHg, and bicuspid aortic valve. Ascending aorta = 29 mm, LA = 32 mm, RV = 26 mm, LV = 48 mm. Septum and left ventricle wall thickness = 10 mm three years ago.

Tomography of thoracic aorta showed aortic arch obstruction with diameters in the ascending aorta (19 mm), in the arch after left carotid artery (14 mm), in the isthmus after the left subclavian artery at the level where aortic coarctation repair had been performed (24 mm) (Figure 1).

Ambulatory Blood Pressure Monitoring showed normal blood pressure in the left arm and blood pressure levels higher than 135/85 mmHg in the right arm in 85% of the time.

Clinical diagnosis: Progressive native coarctation of the aortic arch, and previously repaired coarctation of the aortic isthmus.

Clinical reasoning: the clinical course was compatible with coarctation of the aortic arch due to the pressure gradient between the upper limbs. The absence of symptoms and the physical tolerance denoted a good dynamic behavior. The absence of pressure gradient between the left upper limb and lower limbs predicted the absence of recoarctation of aortic isthmus. These facts were confirmed by echocardiographic and chest computed tomography images (Figure 1).

Differential diagnosis: other diseases accompanied by different levels of aortic obstruction should be considered, such as Kawasaki disease and Takayasu’s arteritis, although they are associated with inflammation and occur earlier in life.

Medical management: given the severity and progression of aortic arch obstruction, systolic artery hypertension and myocardial hypertrophy, surgical correction of the obstruction has been decided on. Placement of a plastic tube between ascending and descending aorta was ruled out and percutaneous treatment was performed. A CP 8Z stent (45 mm) was implanted with a dilation balloon (size 18) from the brachiocephalic artery to the beginning of the descending aorta, with inflation of the stent at the ostium of the left carotid artery (Figure 2). Immediately after stent implantation, the pressure gradient of 20 mmHg decreased and the equalization of pressure was established (96 mmHg). On the next day, blood pressures were 110/70 mmHg in the right arm and 120/80 mmHg in the right dorsalis pedis artery. Heart murmur remained unchanged.

Comments: the progressive aortic coarctation after surgical repair at the aortic isthmus is found in 10‑20% of cases with long term follow‑up. For this reason, aortic coarctation repair performed at early ages has been extended to the aortic arch, using a technique known as “extended end‑to‑end anastomosis” of the aorta. The diagnosis of coarctation of the aortic arch is easily established in the late stages of the disease provided that blood

Mailing Address: Edmar Atik •Office. Rua Dona Adma Jafet, 74 conj.73, Bela Vista. Postal Code 01308‑050, São Paulo, SP – BrazilE‑mail: [email protected] received July 14, 2015; revised manuscript July 16, 2015; accepted September 08, 2015.

DOI: 10.5935/abc.20160130

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Arq Bras Cardiol. 2016; 107(3):276-278

Figure 1 – Chest tomography (A) and aortic angiography (B) clearly show the coarctation of the aortic arch after the left carotid artery, featuring coarctation of this region in progression.

Figure 2 – Angioplasty of aortic arch with CP 8Z stent implanted from the brachiocephalic artery to the isthmus. Angiographic image of aortic obstruction after the left carotid artery (A), stent placed during angioplasty (B), stent and angiography of aortic arch (C), and inflated stent in the beginning of the aortic arch.

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Arq Bras Cardiol. 2016; 107(3):276-278

pressure is systematically measured in all four limbs, as a medical requirement. Narrowing of the aortic arch becomes more evident in the late phase, with no previous parameters for earlier diagnosis of the condition. Therefore, in suspected cases, the extended arch repair for coarctation to becomes the method of choice.

The percutaneous treatment for aortic coarctation, particularly in the isthmus region, has been routinely performed in adult age. Treatment of aortic arch, however, is less frequently performed, despite the favorable clinical course described here and in the literature.

278

Case Report

Complicated Sinus of Valsalva Aneurysm Initially Diagnosed as Atrial MyxomaRafael Plens Teixeira, Pedro Felipe Gomes Nicz, Felipe Lourenço Fernandes, Renner Augusto Raposo Pereira, Roney Orismar Sampaio, Flavio TarasoutchiInstituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo – USP, São Paulo, SP, Brazil

IntroductionAtrial myxoma and sinus of Valsalva aneurysm (SVA) are rare

conditions and possibly underdiagnosed in clinical practice. We report an unusual presentation of a left SVA after an episode of infective endocarditis (IE). The SVA extrinsically compressed the left main coronary artery (LMCA), which was initially diagnosed as a left atrial myxoma.

Case ReportMale patient, 51 years old, was referred to our clinic for

evaluation of aortic and mitral valve dysfunction after an IE by Streptococcus viridans, which was medically treated. The patient did not have any personal history and his only symptom was dyspnea on exertion. Physical examination and transthoracic echocardiogram (TTE) were consistent with significant aortic and mitral regurgitation, and the TTE disclosed an image suggestive of a left atrial myxoma measuring 6.2 x 3.7 cm (Figure 1) and a posterior eccentric mitral regurgitation jet.

Therefore, surgical procedure for aortic and mitral valve replacement was indicated, as well as for removal of the myxoma. Preoperative tests were performed, including cardiac catheterization, transesophageal echocardiography (TEE) and cardiac magnetic resonance (CMR).

The catheterization showed important extrinsic compression of the LMCA by a left SVA that had gone undetected. Both the TEE and the CMR (Figure 2) suggested that this aneurysm was filled with thrombus. Biventricular dysfunction, moderate thickening of the aortic and mitral valves and presence of a hyperechoic image in the anterior mitral leaflet were also observed.

Therefore, the hypothesis of atrial myxoma was ruled out.The surgery consisted in a safety graft of a saphenous vein

graft bypass to the anterior descending artery; the removal of 180 g of aneurysm thrombus; and its occlusion using a bovine pericardium patch. Moreover, 50 g of thrombus adjacent to the anterior mitral leaflet were also removed, where a sinus of Valsalva fistula was found and closed. Finally, mitral and aortic valve replacement was performed, using bioprostheses. According to the subsequently performed histological examination, the previous findings were all suggestive of IE sequel.

DiscussionSVA are usually congenital and more frequent in the

right sinus (65 to 85%), followed by non-coronary ones (10 to 30%) and those located in the left sinus (< 5%).1 According to some researchers, left sinus aneurysms are most frequently acquired and can be caused by atherosclerosis or be the sequelae of diseases such as syphilis or IE.2 These aneurysms can rupture and become life-threatening. The rupture usually occurs into the heart chamber adjacent to the affected sinus. Its most common complications are aortic regurgitation and ventricular septal defect.3,4 LMCA stenosis can also occur due to extrinsic compression. In this case, both LMCA compression and rupture (fistula) occurred.

Because of the close association between the thrombus and the left atrium, the SVA was initially diagnosed as a myxoma.

The urgent surgical repair is recommended in patients with SVA rupture, especially in the event of intracardiac shunts.5,6 For the other types of SVA, surgical repair is generally recommended due to progressive association with poor prognosis. Surgery has satisfactory results and low morbidity and mortality related to the procedure (2%).7,8

In our case, the delay in attaining the correct diagnosis may have exposed the patient to a greater risk for complications.

ConclusionTransesophageal Echocardiography should not be used

alone for the detection of post-endocarditis complications. Unusual complications might go undetected. Transesophageal Echocardiography is mandatory and Cardiac Magnetic Resonance may be of great usefullness.4,9

Mailing Address: Rafael Plens Teixeira •INCOR - UNVAL - Av. Dr. Enéas de Carvalho Aguiar, 44. Postal Code 05403-900, Pinheiros, São Paulo, SP - BrazilE-mail: [email protected], [email protected] received July 31, 2015; revised manuscript October 29, 2015; accepted October 30, 2015.

KeywordsAortic Aneurysm / surgery; Sinus of Valsalva; Aortic

Valve Insufficiency / surgery; Mitral Valve Insufficiency / Surgery; Echocardiography, Transesophageal; Magnetic Resonance Spectroscopy.

DOI: 10.5935/abc.20160126

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Teixeira et al.Complicated sinus of valsalva aneurysm

Arq Bras Cardiol. 2016; 107(3):279-281

Figure 1 – Transthoracic Echocardiography with image suggestive of left atrial myxoma. LV: left ventricle; LA: left atrium.

LV

5

10

15

Aorta

V

LA

Figure 2 – Cardiac Magnetic Resonance showing the presence of sinus of Valsalva aneurysm filled with thrombus. RV: right ventricle; LV: left ventricle.

Aneurysm

Thrombus

Aorta

RVLV

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Teixeira et al.Complicated sinus of valsalva aneurysm

Arq Bras Cardiol. 2016; 107(3):279-281

1. Meier JH, Seward JB, Miller FA Jr, Oh JK, Enriquez-Sarano M, et al. Aneurysms in the left ventricular outflow tract: clinical presentation, causes, and echocardiographic features. J Am Soc Echocardiogr. 1998;11(7):729-45.

2. Chu SH, Hung CR, How SS, Chang H, Wang SS, Tsai CH, et al. Ruptured aneurysms of the sinus of Valsalva in Oriental patients. J Thorac Cardiovasc Surg. 1990;99(2):288-98.

3. Wang ZJ, Zou CW, Li DC, Li HX, Wang AB, Yuan GD, et al. Surgical repair of sinus of Valsalva aneurysm in Asian patients. Ann Thorac Surg. 2007;84(1):156-60.

4. Moustafa S, Mookadam F, Cooper L, Adam G, Zehr K, Stulak J, et al. Sinus of Valsalva aneurysms--47 years of a single center experience and systematic overview of published reports. Am J Cardiol. 2007;99(8):1159-64.

5. Flynn MS, Castello R, McBride LW, Labovitz AJ. Ruptured congenital aneurysm of the sinus of Valsalva with persistent left superior vena cava

imaged by intraoperative transesophageal echocardiography. Am Heart J. 1993;125(4):1185-7.

6. Takach TJ, Reul GJ, Duncan JM, Cooley DA, Livesay JJ, Ott DA, et al. Sinus of Valsalva aneurysm or fistula: management and outcome. Ann Thorac Surg. 1999;68(5):1573-7.

7. Zikri MA, Stewart RW, Cosgrove DM. Surgical correction for sinus of Valsalva aneurysm. J Cardiovasc Surg (Torino). 1999;40(6):787-91.

8. Harkness JR, Fitton TP, Barreiro CJ, Alejo D, Gott VL, Baumgartner WA, et al. A 32-year experience with surgical repair of sinus of valsalva aneurysms. J Card Surg. 2005;20(2):198-204.

9. Blackshear JL, Safford RE, Lane GE, Freeman WK, Schaff HV. Unruptured noncoronary sinus of Valsalva aneurysm: preoperative characterization by transesophageal echocardiography. J Am Soc Echocardiogr. 1991;4(5):485-90.

References

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Image

ST Segment Elevation Myocardial Infarction in Coronary Arteries with Massive EctasyAna Rita G. Francisco, José Duarte, Miguel Nobre Menezes, José Marques da Costa, Pedro Canas da Silva, Fausto J. PintoCentro Hospitalar Lisboa Norte, Hospital de Santa Maria, Lisboa – Portugal

Mailing Address: Ana Rita Francisco •Centro Hospitalar Lisboa Norte, Hospital de Santa Maria. Avenida Professor Egas Moniz. Postal Code 1649-035, Lisboa – PortugalE-mail: [email protected] received March 08, 2016; revised manuscript March 29, 2016; accepted April 01, 2016.

KeywordsAcute Coronary Syndrome; Thrombectomy; Coronary

Artery Disease; Coronary Aneurysm.

DOI: 10.5935/abc.20160093

A 69-year-old caucasian male with a history of hypertension, dyslipidemia, obesity and tobacco use was admitted due to an inferior ST-segment elevation myocardial infarction with two hours evolution. He was treated with aspirin, clopidogrel and unfractioned heparin, and an emergent transradial coronary angiography was performed. Ectasic dilatation of left main, left anterior descending and circumflex arteries were documented, with distal TIMI 2 flow (Figure 1A). The dominant right coronary artery (RCA) was massively dilated proximally and occluded in the mid segment (Figure 1B).

Percutaneous coronary intervention of RCA was attempted, using an AL 1 6 Fr catheter. Thrombus aspiration and balloon dilation of the mid/distal segments were performed, with distal flow recovery (TIMI 2) (Figure 1C). Given the massive ectasy, no stent was implanted. After five days of triple therapy (aspirin, clopidogrel and warfarin) a new coronariography was performed: intracoronary echocardiography revealed an ectasic RCA, with recanalyzed thrombus. The maximum diameter was 14 mm proximally and 8 mm in the middle segment, at the previous occlusion site (Figure 1D).

The patient was managed conservatively with long-term anticoagulation.

Giant coronary artery aneurysms (CAA) are rare and convey a risk of acute coronary syndromes, usually due to local thrombosis. In addition to antiplatelet therapy, anticoagulation is recommended, with surgical or percutaneous excision of CAA in patients with ischemia or a significant change in dimension over time. In this case, given the diffuse character of these lesions, this approach was unsuitable. In recurrent cases, the use of peripheral, self-expanding stents, may be considered.

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Francisco et al.Myocardial infarction with multiple aneurisms

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Figure 1

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Francisco et al.Myocardial infarction with multiple aneurisms

Arq Bras Cardiol. 2016; 107(3):282-284

Vídeo – Watch the videos here: http://www.arquivosonline.com.br/2016/english/10703/video_ing.asp

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Heart Rate Recovery and Selective Serotonin Reuptake InhibitorsLevent CeritNear East University, Nicosia – Cyprus

To the Editor,

I have read, with great interest, the article entitled “Influence of Smoking Consumption and Nicotine Dependence Degree in Cardiac Autonomic Modulation” by Santos et al.,1 recently published in Arquivos Brasileiros de Cardiologia 2016; 106: 510-8. The reseearchers reported that only the intensity of smoking consumption had influences over cardiac autonomic modulation of the evaluated smokers. Smokers with severe smoking consumption intensity presented worse autonomic modulation than moderate ones.1

Antidepressant medications are a first-line treatment option for moderate to severe mood and anxiety disorders;

however, some studies suggest that long-term use may be associated with an increased risk for cardiovascular disease.2-4

Kemp et al.5 reported that all users of selective serotonin reuptake inhibitor - except fluoxetine - display alterations in heart rate or heart rate variability (HRV) in comparison to non users. Similarly, users of paroxetine also display small to moderate reductions in HRV relative to users of citalopram, fluoxetine, and sertraline, but not escitalopram.

In this context, it might be beneficial to give more details about medications due to their effect on cardiac autonomic activity.

Mailing Address: Levent Cerit •Near East University. Postal Code 07100, Nicosia – CyprusE-mail: [email protected], [email protected] received June 06, 2016; revised manuscript July 27, 2016; accepted July 28, 2016.

KeywordsHeart Rate; Tobacco Use; Antidepressive Agents.

1. Santos AP, Ramos D, Oliveira GM, Santos AA, Freire AP, Ito JT, et al. Influence of smoking consumption and nicotine dependence degree in cardiac autonomic modulation. Arq Bras Cardiol. 2016;106(6):510-8.

2. Hamer M, Batty GD, Seldenrijk A, Kivimaki M. Antidepressant medication use and future risk of cardiovascular disease: the Scottish Health Survey. Eur Heart J. 2011;32(4):437–42.

3. Smoller JW, Allison M, Cochrane BB, Curb JD, Perlis RH, Robinson JG, et al. Antidepressant use and risk of incident cardiovascular morbidity and mortality among postmenopausal women in the women’s health initiative study. Arch Intern Med 2009;169(22):2128-39.

4, Whang W, Kubzansky LD, Kawachi I, Rexrode KM, Kroenke CH, Glynn RJ, et al Depression and risk of sudden cardiac death and coronary heart disease in women: results from the Nurses’ Health Study. J Am Coll Cardiol. 2009;53(11):950–8.

5. Kemp AH, Fráguas R, Brunoni AR, Bittencourt MS, Nunes MA, Dantas EM, et al. Differential associations of specific selective serotonin reuptake inhibitors with resting-state heart rate and heart rate variability: implications for health and well-being. Psychosom Med. 2016 May 23. [Epub ahead of print].

References

DOI: 10.5935/abc.20160136

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CeritHeart rate recovery and selective serotonin reuptatake Inhibitors

Arq Bras Cardiol. 2016; 107(3):285-286

ReplyFirstly, I would like to thank you for your interest in our

manuscript entitled “Influence of Smoking Consumption and Nicotine Dependence Degree in Cardiac Autonomic Modulation” by Santos APS et al., recently published in this magazine.

As described in the Methods section of the study, individuals on medications that influence cardiac autonomic modulation were not included. Antidepressants, which are among said medications, are commonly used by smokers, sometimes as a part of a drug therapy to aid in the cessation of the smoking habit.

Even though participants of the study were part of an Antismoking Awareness and Orientation Program, which consists of the association of cognitive behavioral and drug therapy, they had not yet started the offered treatment, and the cardiac autonomic modulation evaluation was done with smokers who were not abstinent or on specific cessation medication.

Given the above, we can state that, in our study, there was no influence of medications that could alter cardiac autonomic modulation.

Ana Paula Soares dos Santos

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