April 19,2007. Introduction Infective endocarditis ; uncommon but life- threatening condition High morbidity and mortality despite advance medical strategies

April 19,2007

IntroductionIntroduction

Infective endocarditis ; uncommon but life-threatening condition

High morbidity and mortality despite advance medical strategies

Many questions about IE prophylaxis efficacy from 1997 AHA guidelines

Classification of Classification of recommendationsrecommendations

Level of evidenceLevel of evidence

1997 document notable1997 document notable

Most case of IE attribute to daily activities bacteremias than invasive procedure

Acknowledgment of possible IE prophylaxis failures

Not well evidence-based(class2b, LOE C) Complicating

New IE prophylaxis guidelines from British Society for Antimicrobial Chemotherapy

Potential consequences of Potential consequences of changeschanges in recommendationsin recommendations

Violate long-standing expectations and practice pattern

Fewer patients eligible for IE prophylaxis Reduce malpractice claims related to IE

prophylaxis Stimulate prospective studies on IE

prophylaxis

Pathogenesis of IEPathogenesis of IE Formation of nonbacterial thrombotic endocarditis

(NBTE) ; turbulence flow Flow from high to low chamber Flow through narrow orifice

Bacteremia Mucosal injury

Bacterial adherence to NBTE FimA protein of viridans streptococci Staphylococcal adhesins of staphylococcus

Proliferation of bacteria within vegetation Rapidly multiply ; left > right More than 90% of mature organisms : inactive ; less response to

ATB

Host’s immune response contribute to clinical manifestations

Historical backgroundHistorical background Bacteremia causes endocarditis Viridans streptococci and enterococci are part of normal flora of oral

cavity and GI,GU tract respectively Susceptible to ATB ATB prophylaxis prevent endocarditis due to streptococci and

enterococci in animal models Large number, poorly documented case report of dental procedure

and IE Temporally relationship between dental procedure and onset of IE Evidence of viridans streptococci bacteremia after dental procedure Low risk of ATB adverse reaction High morbidity and mortality for IE patients

Lack of published data demonstrate prophylactic benefit

Rationale for or against Rationale for or against prophylaxis of IEprophylaxis of IE

Bacteremia-producing dental procedures Frequency, nature, magnitude and duration of bacteremia associated

with dental procedure Impact of dental disease, oral hygiene and type of dental procedure on

bacteremia Impact of ATB prophylaxid on bacteremia from dental procedure Exposure over time of bacteremia from daily activities compare with

dental procedures Results of clinical studies of IE prophylaxis for dental procedure Absolute risk of IE resulting from dental procedure Risk of adverse reactions and cost-effectiveness of prophylactic

therapy Cardiac conditions and endocarditis

Highest predisposition of IE Highest risk of adverse outcome from IE

Bacteremia-producing dental Bacteremia-producing dental proceduresprocedures

Frequency, nature, magnitude and duration of bacteremia associated with a dental procedure Wide variation of frequencies of bacteremia from dental procedure ; tooth

extraction, periodontal surgery, scaling and root planing, teeth cleaning, rubber dam matrix/wedge placement, endodontic procedure

Transient bacteremia occurs frequently in daily activities ; tooth brushing, flossing, wooden toothpicks, water irrigation devices, chewing food

Bacteremia from daily activities >>>> dental procedures Few published data exist on the magnitude of bacteremia from dental procedure

or daily activities life Relatively low bacteremia from dental procedure and daily activities, < 104

CFU/ml, less than experimental IE in animals, 106 to 109 CFU/ml Majority of IE patients had no dental procedure in 2 weeks before onset of

symptom No certain role of bacteremia duration and risk of IE No clinically significant different between dental procedure and daily activities


Impact of dental disease, oral hygiene and type of dental procedure on bacteremia Controversial relationship between poor oral hygiene, extent of

dental and periodontal disease, type of dental procedure and the frequency, nature, magnitude, duration of bacteremia

Available evidences support : good oral hygiene and eradicating dental disease to decrease the frequency of bacteremia from routine daily activities

Numerous dental procedure associated with bacteremia similar to tooth extraction

Bleeding procedure? Lastest guidline : overemphasis ATB prophylaxis and

underemphasis good oral hygiene and routine dental care


Impact of antibiotic therapy on bacteremia from a dental procedure Controversial of ability of ATB to prevent or reduce

frequency, magnitude, duration of bacteremia associated with dental procedure

Amoxicillin ; reduce but not eliminate bacteremia No data of amoxicillin for reduce or prevent IE Contradictory of efficacy of antiseptic


Cumulative risk over time of bacteremias from routine daily activities compared with the bacteremia from a dental procedureCumulative exposure during 1 year to

bacteremia from routine daily activities may be as high as 5.6 million times greater than that resulting from a single tooth extraction

Result of clinical studies of IE Result of clinical studies of IE prophylaxis for dental proceduresprophylaxis for dental procedures

No prospective, randomized, placebo-controlled studies about efficacy of ATB prophylaxis to prevent IE in patients who undergo a dental procedure

Some retrospective studies : suggest a prophylactic benefit but a small in size and insufficient clinical data and prolonged onset of symptoms

Van der Meer ; dental procedure probably caused only a small fraction of cases of IE and prophylaxis ATB would prevent a small number of cases

Strom : dental treatment was not a risk factor for IE even in patients with valvular heart disease

Huge number of prophylaxis doses would be necessary to prevent a very low number of IE cases

Absolute risk of IE resulting from Absolute risk of IE resulting from a dental procedurea dental procedure

No published data accurately determine the absolute risk of EI that result from a dental procedure.

Time frame between bacteremia and the onset of symptoms of IE is usually 7-14 days

Many cases report and reviews included cases with a remote preceding events ; 3 to 6 months

Undetermined whether the bacteremia result from dental procedure or routine daily activities

Exceeding small amount of calculated cases of dental procedure-related IE

Risk of adverse reactions and cost-Risk of adverse reactions and cost-effectiveness of prophylactic therapyeffectiveness of prophylactic therapy

Nonfatal adverse reaction (rash, diarrhea, GI upset) commonly occur, not severe and self limited

In penicillin use and anaphylactic fatalities 36% in known allergy to penicillin 64% in no history of allergy

Fatal anaphylaxis in cephalosporin : less common

Fatal reaction to single dose of macrolide or clindamycin : extremely rare

Summary of bacteremia factorsSummary of bacteremia factors

Lacking of scientific proof for IE due to dental procedure and efficacy of prophylaxis ATB in cardiac risk factors patients

Extremely small number of IE caused by bacteremia-producing dental procedure

Extremely small number of IE cases might be prevented by ATB prophylaxis even 100% effective

Majority of IE : caused by oral microflora and random bacteremia caused by routine daily activites

Dental disease may increase risk of bacteremia associated with routines activities

Emphasis shift from previous dental procedure-related bacteremia and prophylacxis ATB to dental care and oral health

Cardiac conditions and Cardiac conditions and endocarditisendocarditis

Underlying conditions over a lifetime that have the highest predispositon to the acquisition of endocarditis Most common underlying condition for IE

Developing countries : RHD Developed countries : MVP

Steckelberg and Wilson report risk of IE per 100,000 patient-year

MVP without murmur 4.6 MVP with MR murmur 52 RHD 380 – 440 Mechanical or bioprosthetic valve 308 – 383 Valve replacement for native IE 630 Previous IE 740 Valve replacement for prosthetic IE 2160


Underlying conditions over a lifetime that have the highest predispositon to the acquisition of endocarditisCHD

Minor to severe, complex cyanotic heart disease Increase various intracardiac valvular prosthesis,

graft, shunt and other devices Different level of risk for acquisition of IE


Cardiac conditions associated with the highest risk of adverse outcome from endocarditis Viridans streptococcal IE mortality rate

Native valve : ≤ 5% Prosthetic valve : ≥ 20%

Enterococcal IE mortality rate : prosthetic valve > native valve Prosthetic IE take higher risk for : HF, cardiac valve replacement

surgery, perivalvular extension of infection and other complications Relapsing or recurrent IE : greater risk of CHF, cardiac valve

replacement surgery, higher mortality Multiple episodes of native or prosthetic valve IE : greater risk of

additional episodes of IE and more serious complications CHD : complex cyanotic heart disease and postoperative palliative

shunts, conduits or other prostheses have a high lifetime risk of acquiring IE and risk for morbidity and mortality

1997 risk classifications1997 risk classifications


Should IE prophylaxis be recommended for patients with the highest risk of acquisition of IE or for patients with the highest risk of adverse outcome from IE? “In patients with underlying cardiac conditions

associated with the highest risk of adverse outcome from IE, IE prophylaxis for dental procedures may be reasonable, even though we acknowledge that its effectiveness is unknown (class 2b, LOE B)”

Regimens recommendedRegimens recommended

General principlesSingle dose before the procedureUp to 2 hours administration after procedure if

inadvertently not administrated before procedure

Beware IE in high risk patient who underwent the invasive procedure

Regimens for dental procedureRegimens for dental procedure

Class 2b, LOE C (unknown effectiveness)

Exists evidences of drug-resistance strains

Regimens for respiratory tract Regimens for respiratory tract proceduresprocedures

No published data conclusively demonstrate a link between RS procedure and IE

ATB prophylaxis was recommend in an invasive procedure involve incision of mucosa : tonsillectomy,

adenoidectomy Infection drainage : abscess, empyema

No role of ATB prophylaxis in bronchoscope without incision of mucosa

The same patient and regimen as dental procedure Beware staphylococcus

Recommendations for GI or GU Recommendations for GI or GU tract procedurestract procedures

Enterococci infection : GI and GU tract No published data link between IE and GI, GU tracts

procedures No studies exist demonstrate ATB prophylaxis prevent

IE in GI, GU procedures Increase frequency of enterococci resistant to penicillin,

vancomycin, aminoglycosides, but unknown significance about GI, GU tracts procedures IE prevention

Prophylaxis ATB solely to prevent IE is not recommend Diagnostic esophagogastroduodenoscopy colonoscopy


Reasonable ATB prophylaxis in indicated patients with : Established GI or GU tract infection or Receive ATB to prevent wound infection or sepsis

associated with GI or GU tract procedure

ATB against entercocci : penicillin, ampicillin, piperacillin, vancomycin include in regimen

No published studies demonstrate efficacy

Class 2B, LOE B


Reasonable ATB to eradicate enterococci in indicated patient with : Elective cystoscopy or Other urinary tract manipulation

Enterococcal urinary tract infection or colonization

Reasonable empiric or specific ATB against enterococci in non-elective procedure

Class 2B, LOE B

Recommendations for procedures Recommendations for procedures on infected skin, skin structure, on infected skin, skin structure,

musculoskeletal tissuemusculoskeletal tissue

Reasonable therapeutic regimen active against staphylococci and β-hemolytic streptococci in indicated patients with :Undergo surgical procedure that involves

infected skin, skin structure, musculoskeletal tissue

Class 2B, LOE C

Documents

April 19,2007. Introduction Infective endocarditis ; uncommon but life- threatening condition High morbidity and mortality despite advance medical strategies