July 6, 2010 On-X Prosthetic Heart Valve (On-X Life

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July 6, 2010

On-X Prosthetic Heart Valve (On-X Life Technologies, Inc.)

Search StrategyA literature search of MEDLINE and EMBASE was completed on July 3, 2010, using the terms On-X AND heart, On-X ANDcardiac, On-X AND mitral, and On-X AND aortic. The search was limited to abstracts of English-language, human clinicaltrials and review articles published in the last 10 years.

Description of Search ResultsTwenty-nine abstracts were retrieved including:

1 ongoing, longitudinal, multi-center, North American study (n=284, abstract #10); 1 multicenter, case series study (n=301,abstract #6); 1 multicenter case series study with a maximum 5-year follow-up (n=532, abstract #21); 2 multicenter caseseries studies (n=301, abstract #23 and n=248, abstract #25); 1 case series with a ten-year follow-up (n=428, abstract #8);4 case series studies (n=400, abstract #14; n=47, abstract #15; n=34, abstract #18; and n=27, abstract #27);

1 cohort study involving “…a socioeconomically disadvantaged population…” (n=438, abstract #11);

1 comparison study involving the On-X versus the “Top Hat valve (CarboMedics Inc…” (n=52, abstract#12); 1 comparisonstudy evaluating the closing sounds of the On-X versus the “ATS valves” [ATS Medical Inc.] and the “St. Jude Medicalheart valve prostheses” (n=47, abstract #13); 1 comparison study of the closing sounds of the On-XC versus St. JudeMedical (SJM) heart valve prostheses (n=34, abstract #28); 1 comparison study to “…to evaluate the clinical performanceof the Carbomedics, Medtronic Hall and On-X valves in the challenging setting of a Third World population with incompleteanticoagulation coverage…” (n=324, abstract #17); 1 comparison study of the “…hemodynamic function after aortic valvereplacement (AVR) using the On-X valve, in comparison with St. Jude Medical (SJM) HP bileaflet valves…” (n=40, abstract#29);

5 case reports (abstracts #1, #2, #3, #5, and #7);

1 valve size comparison, laboratory study (abstract #4); 1 comparison laboratory study examining “…valvular energyloss and transvalvular gradients…” (abstract #9); 1 comparison laboratory study evaluating “…Doppler and cathetergradients…” (abstract #16); 1 laboratory comparison study comparing “…performance of four 25 mm bileaflet valves ofdifferent designs… (abstract #20); 2 prosthetic valve performance comparison laboratory studies (abstracts #22 and #24);1laboratory study “…of the classical and modified forms of the continuity equation in the on-X prosthetic heart valve in theaortic position..” (abstract #26); and

1 review article (abstract #19).

Links to the full text articles of abstracts #1, #4, #6, #7, #11, #12, #14, #17, #18, #21, and #25 can be found underthe Online Articles section below.

Related Hayes Reports:Carpentier-Edwards PERIMOUNT Magna™ Mitral Heart Valve (Edwards Lifesciences LLC) for Mitral Valve ReplacementCoreValve ReValving® SystemEdwards Sapien™ Transcatheter Heart ValveRobotically Assisted Cardiac Valve Replacement Using the da Vinci Robotic System (Intuitive Surgical Inc.)Transcatheter Aortic Valve Repair for Aortic Stenosis

This report is intended to provide research assistance and general information only. It is not intended to be used as the sole basis for determining coverage, reimbursement, or technology acquisition. Anydecision regarding claims eligibility or benefits, or acquisition of a health technology is solely within the discretion of your organization. Hayes, Inc. assumes no responsibility or liability for such decisions.This report is not intended to be used as the sole basis for defining treatment protocols, or medical modalities, nor should it be construed as providing medical advice regarding treatment of an individual’sspecific case. This report has been prepared for you by Hayes, Inc. and is for informational purposes only. This report is a SAMPLE and not intended for distribution. © 2010 Winifred S. Hayes, Inc.

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Regulatory Agency InformationFood and Drug Administration (FDA):The original FDA premarket approval (PMA) for the On-X® Prosthetic Heart Valve, Model ONXA (P000037) occurred onMay 30, 2001 and was issued to Medical Carbon Research Institute (MCRI™), LLC. According to the approval letter: “…This device is indicated for replacement of diseased, damaged, or malfunctioning native or prosthetic heart valves in theaortic position…”

Since the original approval, there have been 17 Supplement PMAs. According to the manufacturer’s website, sectionCompany. History: The On-X Story: “…In 2007, the company changed its name from MCRI to On-X Life Technologies, Inc.(On-X LTI)…” Therefore, the 3 most recent Supplement PMAs (2008, 2009, and 2010) are listed under the manufacturername On-X Life Technologies Inc.

The newest Supplemental PMA (P000037 S017) was granted for the “…Approval to change the material specifications forthe sewing cuff ptfe fabric used in the assembly of the on-x valve…” To view the original PMA, for the On-X Prosthetic HeartValve, and/or any of the Supplement PMAs, please see the FDA Approvals section below.

A search of the FDA’s Manufacturer and User Facility Device Experience (MAUDE) database retrieved approximately 52adverse events for the On-X Prosthetic Heart Valve. To view a list of these adverse events, please enter the search terms“On-X Prosthetic Heart Valve”, and highlight all years under the Date Report Received by FDA section, at this MAUDEdatabase site: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/TextSearch.cfm

(NOTE: According to the FDA: “…MAUDE data represents reports of adverse events involving medical devices. Thedata consists of voluntary reports since June 1993, user facility reports since 1991, distributor reports since 1993, andmanufacturer reports since August 1996. MAUDE may not include reports made according to exemptions, variances, oralternative reporting requirements granted under 21 CFR 803.19…”).

Of special note, the FDA is drafting a guidance document for prosthetic heart valves: Draft Guidance for Industry andFDA Staff: Heart Valves - Investigational Device Exemption (IDE) and Premarket Approval (PMA) Applications (Documentissued on: January 20, 2010). According to the introduction section of this document “…The guidance is intended to providerecommendations for the preparation of investigational device exemption (IDE) and premarket approval (PMA) applicationsfor replacement heart valves that are not allograft heart valves or more than minimally manipulated allograft heart valves.This guidance[1] describes FDA’s recommendations about manufacturing, preclinical in vitro bench testing, preclinical in vivostudies, clinical investigations, and labeling that are different from or in addition to the recommendations of the InternationalOrganization For Standardization (ISO), ISO 5840:2005, “Cardiovascular Implants - Cardiac Valve Prostheses” (ISO 5840).[2] Although the guidance provides information complementary to ISO 5840:2005,[3] the guidance can also be used withother methods equivalent to ISO 5840:2005…” For more information regarding this guidance document, please click on thisFDA link: http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm193096.htm

FDA Approvals:For more information regarding a specific PMA for the On-X Prosthetic Heart Valve, please enter the PMA number or toview a list of all of the On-X PMA approvals, please enter the search term On-X, into this FDA PMA database form: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pmasimplesearch.cfm

P000037 S017: On-X® Prosthetic Heart Valve (On-X Life Technologies Inc.) approved on January 14, 2010P000037: On-X® Prosthetic Heart Valve, Model ONXA (Medical Carbon Research Institute (MCRI™), LLC) approvedMay 30, 2001

Centers for Medicare & Medicaid Services (CMS):


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http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/TextSearch.cfm

http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm193096.htm

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pmasimplesearch.cfm

http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfPMA/pmasimplesearch.cfm


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No CMS National Coverage Determination (NCD) was found for the On-X Prosthetic Heart Valve or for prosthetic heartvalves in general.

CE Marking: The On-X Prosthetic Heart Valve not only was granted CE Marking in 1998 for distribution in Europe, butwas also added to the Australian Register of Therapeutic Goods in 2002, allowing for distribution in Australia and NewZealand. For more information, please see the press release links under the Manufacturer/Distributor/Lab/Medical CenterSites section below.

ConclusionsThe scope and quality of the clinical studies found during the abstract search are sufficient to conduct an evidence-basedassessment of the safety and efficacy of the On-X Prosthetic Heart Valve in a Hayes Health Technology Brief (HTB) and/orHayes Medical Technology Directory report. HTB and Medical Technology Directory reports are completed as permitted byour production schedule, with priority given to frequently requested topics.

Other Relevant Information

Manufacturer/Distributor/Lab/Medical Center Sites:On-X Life Technologies Inc: http://www.onxlti.com/index.html

Company. History: The On-X Story (contains information regarding company’s name change in 2007): http://www.onxlti.com/onxlti-onx-story.htmlHeart Valve Product Group: http://www.onxlti.com/onxlti-heart-valve.htmlReal Progress from Real Change (page for medical professionals): http://www.onxlti.com/onxlti-hv-med-home.htmlProspective Randomized On-X Valve Anticoagulation Clinical Trial (PROACT). US FDA IDE Approved: http://www.onxlti.com/onxlti-hv-proact.htmlFDA Clinical Results: http://www.onxlti.com/onxlti-hvm-fda-data.htmlReferences/Bibliography: http://www.onxlti.com/onxlti-hvm-references.htmlClinical Issues and Updates: http://www.onxlti.com/onxlti-hvm-clinical-updates.htmlPress release. Australian TGA Approves On-X Valves (published on March 14, 2002): http://www.onxlti.com/onxlti-news-australian-tga-approves.htmlPress release. E.U. Grants CE Mark for the On-X Valve (published on July 24, 1998): http://www.onxlti.com/onxlti-news-eu-grants-ce-mark.html

Online Articles:A case report of valve dysfunction associated with abrasion of the Delrin disk used in early Björk-Shiley mitral valves requiringresurgery (Masumoto et al., 2009), Annals of Thoracic & Cardiovascular Surgery [Full Text Article of Abstract #1]: http://www.atcs.jp/pdf/2009_15_2/126.pdf

Which valve and which size should we use in the valve-on-valve technique for re-do mitral valve surgery? (Shibata et al.,2009), Interactive Cardiovascular & Thoracic Surgery [Full Text Article of Abstract #4]: http://icvts.ctsnetjournals.org/cgi/reprint/8/2/206

Choice of Prosthetic Heart Valve in Today’s Practice (Oakley et al., 2008), Circulation: http://circ.ahajournals.org/cgi/reprint/117/2/253

Multicentered European Study on Safety and Effectiveness of the On-X Prosthetic Heart Valve: Intermediate Follow-Up(Palatianos et al., 2007), Annals of Thoracic Surgery [Full Text Article of Abstract #6]: http://ats.ctsnetjournals.org/cgi/reprint/83/1/40


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http://www.onxlti.com/index.html

http://www.onxlti.com/onxlti-onx-story.html

http://www.onxlti.com/onxlti-onx-story.html

http://www.onxlti.com/onxlti-heart-valve.html

http://www.onxlti.com/onxlti-hv-med-home.html

http://www.onxlti.com/onxlti-hv-proact.html

http://www.onxlti.com/onxlti-hv-proact.html

http://www.onxlti.com/onxlti-hvm-fda-data.html

http://www.onxlti.com/onxlti-hvm-references.html

http://www.onxlti.com/onxlti-hvm-clinical-updates.html

http://www.onxlti.com/onxlti-news-australian-tga-approves.html

http://www.onxlti.com/onxlti-news-australian-tga-approves.html

http://www.onxlti.com/onxlti-news-eu-grants-ce-mark.html

http://www.onxlti.com/onxlti-news-eu-grants-ce-mark.html

http://www.atcs.jp/pdf/2009_15_2/126.pdf

http://www.atcs.jp/pdf/2009_15_2/126.pdf

http://icvts.ctsnetjournals.org/cgi/reprint/8/2/206


http://circ.ahajournals.org/cgi/reprint/117/2/253


http://ats.ctsnetjournals.org/cgi/reprint/83/1/40

http://ats.ctsnetjournals.org/cgi/reprint/83/1/40


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Repair of recoarctation and aortic valve replacement with the On-X valve in a pediatric patient: A case report (Sasaki et al.,2007), Journal of Nippon Medical School [Full Text Article of Abstract #7]: http://www.jstage.jst.go.jp/article/jnms/74/2/173/_pdf

The On-X® heart valve: Mid-term results in a poorly anticoagulated population (Williams and van Riet, 2006),Journal of Heart Valve Disease [Full Text Article of Abstract #11]: http://www.ksantamedica.ru/data/file/Art-MidtermResultsSAfricaMervynWilliams.pdf

Early clinical experience with the On-X prosthetic heart valve (Özyurda et al., 2005), Interactive CardioVascular and ThoracicSurgery [Full Text Article of Abstract #14]: http://icvts.ctsnetjournals.org/cgi/reprint/4/6/588

A randomized comparison of the MCRI On-X and CarboMedics Top Hat bileaflet mechanical replacement aortic valves: Earlypostoperative hemodynamic function and clinical events (Chambers et al., 2005), Journal of Thoracic and CardiovascularSurgery [Full Text Article of Abstract #12]: http://jtcs.ctsnetjournals.org/cgi/reprint/130/3/759

A comparison of mechanical valve performance in a poorly anticoagulated community (Williams et al.,2004), Journal of Cardiac Surgery [Full Text Article of Abstract #17]: http://www.kardiotechnik.at/downloads/acomparisonofmechanicalvalveperformanceinapoor.pdf

Leaflet escape in a new bileaflet mechanical valve: TRI technologies (Bottio et al., 2003) Circulation [Full Text Article ofAbstract #18]: http://circ.ahajournals.org/cgi/reprint/107/18/2303

The On-X Prosthetic Heart Valve at Five Years (Moidl et al., 2002), The Annals of Thoracic Surgery [Full Text Article ofAbstract #21]: http://ats.ctsnetjournals.org/cgi/reprint/74/4/S1312

Examination of hemolytic potential with the On-X(R) prosthetic heart valve (Birnbaum et al., 2000), Journal of Heart ValveDisease [Full Text Article of Abstract #25]: http://www.ksantamedica.ru/data/file/Art-ExaminationofHemolytic.pdf

Clinical Trials:To review the details of a clinical trial, insert the study number into the search field of the form found at this site: http://clinicaltrials.gov/ct2/search.

NCT00639782: Prospective Randomized On-X Versus SJM Evaluation Trial (PROSE)

NCT00291525: Randomized On-X Anticoagulation Trial

A comprehensive search of the Internet yielded no information regarding payer coverage policies or evidence-based practiceguidelines for the On-X Prosthetic Heart Valve.

Original Search: July 3, 2010

Search Results with AbstractsMEDLINE, EMBASESearch terms: On-X AND heart, On-X AND cardiac, On-X AND mitral, and On-X AND aorticSearch limits: Abstracts of English-language, human clinical trials and review articles published in the last 10 years


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http://www.jstage.jst.go.jp/article/jnms/74/2/173/_pdf

http://www.jstage.jst.go.jp/article/jnms/74/2/173/_pdf

http://www.ksantamedica.ru/data/file/Art-MidtermResultsSAfricaMervynWilliams.pdf

http://www.ksantamedica.ru/data/file/Art-MidtermResultsSAfricaMervynWilliams.pdf


http://jtcs.ctsnetjournals.org/cgi/reprint/130/3/759

http://www.kardiotechnik.at/downloads/acomparisonofmechanicalvalveperformanceinapoor.pdf

http://www.kardiotechnik.at/downloads/acomparisonofmechanicalvalveperformanceinapoor.pdf


http://ats.ctsnetjournals.org/cgi/reprint/74/4/S1312

http://www.ksantamedica.ru/data/file/Art-ExaminationofHemolytic.pdf

http://clinicaltrials.gov/ct2/search

http://clinicaltrials.gov/ct2/search


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Search yield: 71 citationsRetrieved: 29 abstracts

1 : Annals of Thoracic & Cardiovascular Surgery. 15(2):126-8, 2009 Apr.

A case report of valve dysfunction associated with abrasion of the Delrin disk used in early Bjork-Shiley mitral valvesrequiring resurgery.

Masumoto H. Shimamoto M. Yamazaki F. Nakai M. Fujita S. Miura Y. Itonaga T. Ito H.

A 39-year-old woman had undergone mitral valve replacement (MVR) (29-mm Bjork-Shiley Delrin disk) at 6years of age. Severe mitral regurgitation, aortic regurgitation, and left ventricular dilatation were detected byechocardiography in October 2006, and MVR (ON-X 25 mm) and aortic valve replacements (St. Jude MedicalRegent, 21 mm) were performed in December. The Delrin disk of the previous prosthetic valve, located at the positionof the mitral valve, was markedly abraded, broadening the clearance from the valve seat. The postoperative coursewas smooth without complications, and the patient was discharged, walking by herself, on day 19 after surgery.A Delrin disk was used for the tilting valve in early Bjork-Shiley valves, but has been replaced by pyrolytic carbonbecause of problems with durability of the Delrin material. Follow-ups of patients who have undergone proceduresusing Delrin disks ares necessary, with consideration of valve replacement.Stage

MEDLINEAuthors Full Name: Masumoto, Hidetoshi. Shimamoto, Mitsuomi. Yamazaki, Fumio. Nakai, Masanao. Fujita, Shoji. Miura, Yujiro. Itonaga, Tatsuya. Ito, Hiroki.

Institution: Department of Cardiovascular Surgery, Shizuoka City Hospital, Shizuoka, Japan.

2 : Saudi Medical Journal. 30(7)(pp 964-966), 2009.

Successful thrombolytic therapy for stuck mitral mechanical valve.

Obied H.Y., Ibrahim M.F., Latroche B.S., Mroue M.M.

Thrombosis of a mechanical prosthetic valve is a serious and fortunately it is a rare complication of cardiac valvereplacement. We present a case of prosthetic mechanical valve On-X 31/33 mm thrombosis thrombus size 8 x 14mm on a mitral position, which was treated with a successful intravenous thrombolytic therapy of streptokinaseinfusion over 10 hours repeated twice with no complications.

Institution: (Obied, Ibrahim, Latroche, Mroue) Prince Salman Heart Center, King Fahad Medical City, PO Box 59046,Riyadh 11525, Saudi Arabia.

Publisher: Saudi Arabian Armed Forces Hospital

3 : Journal of Heart and Lung Transplantation. 28(9)(pp 981-983), 2009.

Bench Replacement of Donor Aortic Valve Before Orthotopic Heart Transplantation.

Saito S., Matsumiya G., Ueno T., Sakaguchi T., Kuratani T., Ichikawa H., Sawa Y.

Organic valve disease has been considered an absolute contraindication for acceptance as a donor heart. However,the severe shortage of donor hearts has prompted the use of marginally acceptable hearts to maximize theuse of donor hearts. This report concerns a patient with repeated left ventricular assist system complicationswho underwent successful heart transplantation with a marginal donor heart requiring concomitant aortic valve


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replacement for mild aortic stenosis due to a calcified congenitally bicuspid valve. copyright 2009 InternationalSociety for Heart and Lung Transplantation.

Institution: (Saito, Matsumiya, Ueno, Sakaguchi, Kuratani, Ichikawa, Sawa) Division of Cardiovascular Surgery,Department of Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.

Publisher: Elsevier USA

4 : Interactive Cardiovascular & Thoracic Surgery. 8(2):206-10, 2009 Feb.

Which valve and which size should we use in the valve-on-valve technique for re-do mitral valve surgery?

Shibata T. Inoue K. Ikuta T. Bito Y. Yoshioka Y. Mizoguchi H.

The valve-on-valve (VOV) technique is that a mechanical valve is implanted on the sewing cuff of the previousbioprosthesis after removing degenerated leaflets. We conducted an in vitro study to determine the size-match ofthe valves for VOV technique. The Carpentier-Edwards pericardial (CEP) valve and Mosaic valve were used. Wemeasured the inner diameter of the bioprosthesis after removing the leaflets. We investigated five mechanical mitralvalves and two mechanical aortic valves (inverted use). The mitral valves used in this study were the ATS valve(ATS), the CarboMedics standard valve (CMS), the CarboMedics OptiForm valve (CMO), the On-X valve, and theSt Jude valve (SJM). Two aortic mechanical valves, CarboMedics and St Jude Regent valves, were investigated forinverted use. After removing the tissue leaflets, the inner diameter of the Mosaic valve was 3 mm smaller than that ofthe CEP valve even in the same catalogue labeling size. The outer diameters of the housing of the ATS, CMS, CMO,On-X, and SJM valves of the same catalogue size (25 mm) were 25.7, 25.8, 22.0, 25.0, and 23.2 mm, respectively.SJM and CMO valves are the favorite mechanical valve for the VOV technique in terms of the profile and size-match.

MEDLINEAuthors Full Name: Shibata, Toshihiko. Inoue, Kazushige. Ikuta, Takeshi. Bito, Yasuyuki. Yoshioka,Yoshiteru. Mizoguchi, Hiroki.

Institution: Department of Cardiovascular Surgery, Osaka City General Hospital, Miyakojima, Osaka, Japan. [email protected]

5 : Heart Lung and Circulation. 17(3)(pp 259-261), 2008.

Urgent Transcatheter Closure of Patent Foramen Ovale followed by Elective Right-Sided Valve Surgery forDecompensated Carcinoid Heart Disease. Hayashi Y., McGaw D.J., Goldstein J.

The presence of a patent foramen ovale (PFO) is associated with morbidity and mortality in patients with carcinoidheart disease (CHD). We report a 66-year-old male patient with tricuspid and pulmonary valve regurgitationsecondary to CHD, who developed severe hypoxia due to a right-to-left shunt through a PFO. A 35 mm Amplatzerseptal occluder was deployed to reduce the right-to-left shunt as an urgent procedure. Tricuspid and pulmonary valvereplacements were electively performed using ON-X mechanical prostheses (31/33 mm and 19 mm, respectively) 70days after the percutaneous procedure. Transcatheter closure of a PFO prior to definitive right-sided valve surgerycan be a useful treatment for CHD patients with acute haemodynamic derangement. copyright 2007 AustralasianSociety of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand.

Institution: (Hayashi, Goldstein) Cardiothoracic Surgery Unit, Monash Medical Centre, 246 Clayton Road, Clayton,Vic. 3168, Australia. (McGaw) Cardiology Department, Monash Medical Centre, 246 Clayton Road, Clayton, Vic.3168, Australia. (Goldstein) Department of Surgery (MMC), Monash University, 246 Clayton Road, Clayton, Vic.3168, Australia.


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6 : Annals of Thoracic Surgery. 83(1)(pp 40-46), 2007.

Multicentered European Study on Safety and Effectiveness of the On-X Prosthetic Heart Valve: Intermediate Follow-Up.

Palatianos G.M., Laczkovics A.M., Simon P., Pomar J.L., Birnbaum D.E., Greve H.H., Haverich A.

Background: This study was performed to determine the safety and effectiveness of the On-X valve, a novelmechanical valve substitute. Methods: Eleven centers participated in a European, multicentered, longitudinal,nonrandomized study of the On-X valve performance. Isolated aortic or mitral valve replacement with an On-X valvewas studied in 301 patients. Aortic valve replacement was performed in 184 patients (average follow-up, 5.0 years),whereas mitral valve replacement was performed in 117 patients (average follow-up, 4.4 years). Results: In patientswith aortic valve replacement, mean transvalvular pressure gradients ranged from 8.3 to 4.7 mm Hg and effectiveorifice areas from 1.5 to 2.7 cm2, for 19-mm through 25-mm valves, respectively. After mitral valve replacement,mean gradient was 4.2 mm Hg and effective orifice area by pressure half-time was 2.6 cm2 regardless of valvesize. Hemolysis was low, with postoperative serum lactate dehydrogenase at 225 +/- 41 IU (mean +/- standarddeviation) or 253 +/- 65 IU, after aortic valve replacement or mitral valve replacement, respectively (upper normalvalue, 250 IU). At 1 year or greater postoperatively, 91.6% of patients after aortic valve replacement and 84.6%after mitral valve replacement were in New York Heart Association functional class I or II. Adverse event rates inpercent per patient-year after aortic valve replacement or mitral valve replacement were thromboembolism, 0.88 or1.76; thrombosis, 0.11 or 0.20; bleeding, 0.77 or 1.96, respectively. Late mortality was 1.97% or 2.55%, respectively.Conclusions: At the intermediate follow-up, the On-X valve exhibited improved hemodynamics, low hemolysis within-range lactate dehydrogenase, and low adverse event rates, particularly in the aortic position. copyright 2007 TheSociety of Thoracic Surgeons.

Institution: (Palatianos) Onassis Cardiac Surgery Center, Athens, Greece. (Laczkovics) UniversitatklinikumBergmannsheil, Bochum, Germany. (Simon) AKH-Wien, Vienna, Austria. (Pomar) University of Barcelona, Spain.(Birnbaum) University Clinic, Regensburg, Germany. (Greve) Klinikum Krefeld, Krefeld, Germany. (Haverich)Medical High School, Hanover, Germany.

7 : Journal of Nippon Medical School. 74(2)(pp 173-176), 2007.

Repair of recoarctation and aortic valve replacement with the On-X valve in a pediatric patient: A case report.

Sasaki T., Takahashi Y., Ando M., Wada N.

A 10-year-old boy had undergone conventional two-stage surgery that includeed repair of aortic coarctation withpulmonary artery banding as an initial operation followed by closure of a ventricular septal defect as a secondaryprocedure. Following these procedures, aortic coarctation recurred, and balloon angioplasty was performed threetimes. Aortic recoarctation, however, persisted, and aortic stenosis and regurgitation and pulmonary stenosisgradually developed. An operation was therefore performed to repair recoarctation, aortic stenosis and regurgitation,and pulmonary stenosis. Patch aortoplasty was performed for recoarctation. The aortic valve was replaced with a19 mm On-X valve, with Konno root enlargement. Pulmonary arterial patch plasty was also performed. During aorticarch reconstruction, selective cerebral perfusion was performed via the innominate artery and left carotid artery,and the lower half of the body was perfused through a cannula in the left femoral artery. The postoperative coursewas uneventful, and aortography revealed a well-reconstructed aortic arch free of obstruction. There were no valve-related complications.

Institution: (Sasaki, Takahashi, Ando, Wada) Department of Pediatric Cardiac Surgery, Sakakibara Heart Institute,Tokyo, Japan. (Sasaki) Department of Pediatric Cardiac Surgery, Sakakibara Heart Institute, 3-16-1 Asahi-cho,Fuchu-shi, Tokyo 183-0003, Japan.


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8 : Journal of Heart Valve Disease. 16(5)(pp 551-557), 2007.

Single-center experience with the On-X prosthetic heart valve between 1996 and 2005.

Tossios P., Reber D., Oustria M., Holland-Letz T., Germing A., Buchwald D., Laczkovics A.

Background and aim of the study: Herein are presented long-term results for the On-X mechanical heart valve.All On-X heart valve recipients since the first implantation worldwide at the University of Bochum in September1996 were followed retrospectively; the present authors' single-center experience over a period of almost 10 yearsis reported. Methods: A total of 428 patients (255 males, 173 females; mean age 62.7 years) underwent eitheraortic valve replacement (AVR; n = 264) or mitral valve replacement (MVR; n = 164) using the On-X prosthesis.Preoperatively, 329 patients (76.8%) were in NYHA class III or IV. Approximately 5% of AVR and 23% of MVRpatients had undergone previous cardiac surgery. Concomitant surgery was performed in 189 patients (44.2%). Themean follow up was 3.9 years, and cumulative follow up 1,625 patient-years (pt-yr); the overall follow up rate was98.7%. Results: Early mortality (<30 days) was 3.7% after AVR and 14.0% after MVR, with valve-related mortalityrates of 0.4% and 1.2%, respectively. At autopsy (n = 12) all implants were intact. Freedom from valve-related deathat nine years was 85.0 +/- 3.9% after AVR and 87.6 +/- 3.2% after MVR. The overall survival rate was 67.9 +/- 4.3%after AVR and 52.7 +/- 8.1% after MVR. The linearized rate of thromboembolism for AVR and MVR was 1.49%/pt-yr and 1.61%/pt-yr; of thrombosis 0%/pt-yr and 0.35%/pt-yr; of hemorrhage 0.93%/pt-yr and 1.43% /pt-yr; ofendocarditis 0.37%/pt-yr and 0.17%/pt-yr; of non-structural failure 0.18%/pt-yr and 1.43%/pt-yr; and of reoperation0.28%/pt-yr and 0.53%/pt-yr. There were no cases of structural valve failure. Conclusion: After almost one decade ofclinical experience in a single center, the On-X heart valve continues to be reliable and effective. copyright Copyrightby ICR Publishers 2007.

Institution: (Tossios, Reber, Oustria, Buchwald, Laczkovics) Department of Cardiothoracic Surgery, BGUniversitatsklinikum Bergmannsheil, University of Bochum, Burkle-de-la-Camp-Platz 1, 44789 Bochum, Germany. (Holland-Letz) Department of Medical Informatics, Biometry and Epidemiology, BG UniversitatsklinikumBergmannsheil, University of Bochum, Burkle-de-la-Camp-Platz 1, 44789 Bochum, Germany. (Germing)Department of Cardiology, BG Universitatsklinikum Bergmannsheil, University of Bochum, Burkle-de-la-Camp-Platz1, 44789 Bochum, Germany.

9 : Journal of Heart Valve Disease. 15(4):549-56, 2006 Jul.

Hemodynamics of high-performance bileaflet valves: comparison to simulated clinical Doppler measurements.

Dohmen G. Schmitz C. Schmitz-Rode T. Steinseifer U. Autschbach R.

BACKGROUND AND AIM OF THE STUDY: The newly designed, so-called 'high performance' bileaflet heart valveprostheses are suggested to be especially beneficial in small sizes. Herein, valvular energy loss and transvalvulargradients were evaluated using an in-vitro pulsatile flow model for aortic prostheses (St. Jude Medical Regent andOn-X, sizes 19-23 mm). Gradients were compared with simulated clinically derived Doppler gradients to determinethe extent of pressure recovery. METHODS: Valves were analyzed using a pulsatile circulatory mock loop simulatorat heart rates of 70 and 110 bpm, and at cardiac outputs of 2, 4, 5, and 7 l/min, respectively (FDA requirements).Measurements consisted of computed calculation of energy loss and determination of mean pressure gradient bypressure transducers. A Doppler probe was mounted into the device for simultaneous measurement of Dopplergradient according to the Bernoulli equation. RESULTS: The systolic energy loss of the SJM Regent valve averaged5.0 +/- 4.6% (range: 0.2 to 14.9%) of the effective forward energy, while that for the On-X valve was 6.5% (range:0.7-22.8%). Total energy loss was 9.9% (range: 4.8-22.1%) for the SJM Regent valve, and 12.7% (range: 6.5-27.7%)for the On-X valve. The average extent of pressure recovery was 64% for both valve types. CONCLUSION: Alltested valves were characterized by excellent hemodynamic performance, with overall low systolic and total energylosses, but results were slightly favorable for the SJM Regent valve. Valve performance was concluded to be much


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better than expected by clinical routine Doppler measurements, which significantly overestimates transvalvulargradients; this effect was explained by pressure recovery. Nevertheless, Doppler gradient remains a valuable followup technique for patients with heart valve prostheses.Stage

MEDLINEAuthors Full Name: Dohmen, Guido. Schmitz, Christoph. Schmitz-Rode, Thomas. Steinseifer, Ulrich. Autschbach, Rudiger.

Institution: Clinic for Thoracic and Cardiovascular Surgery, University Hospital Aachen, Medical Faculty RWTH,Aachen, Germany. [email protected]


North American multicenter experience with the On-X prosthetic heart valve.

McNicholas K.W., Ivey T.D., Metras J., Szentpetery S., Marra S.W., Masters R.G., Dilling E.W., Slaughter M.S.,Mack M.J.

Background and aim of the study: This ongoing, longitudinal, multi-center, North American study was designedto evaluate the safety and effectiveness of the On-X valve. Methods: The On-X valve was implanted in isolatedaortic (AVR) and mitral (MVR) valve replacement patients at nine North American centers. Follow up was 98.6%complete. Anticoagulation compliance was evaluated by collection of international normalized ratio (INR) results inall patients throughout their postoperative follow up. Adverse events were recorded according to the ARTS/STSguidance criteria. Hematologic studies were conducted postoperatively to evaluate hemodynamics and hemolysis.Results: In total, 142 AVR and 142 MVR implants were perform ed; the mean follow up was 4.5 years; total follow upwas 1,273 patient-years (pt-yr). At implant, the mean patient age was 59.2 years (range: 28 to 85 years); 71.8% ofpatients who underwent AVR and 33.1% who underwent MVR were males. Preoperatively, 89.4% of AVR patientsand 56.3% of MVR patients were in sinus rhythm. The cardiac disease etiology was primarily stenotic, calcificdegeneration in AVR and rheumatic or degenerative regurgitation in MVR. Hemolysis represented by postoperativeelevation of serum lactate dehydrogenase was very low (median 217 IU after AVR and 251 IU after MVR at oneyear (82% AVR and 98% MVR of upper normal). Late adverse event rates were low, most notably thromboembolism(0.9%/pt-yr after AVR; 1.6%/pt-yr after MVR) and thrombosis. Kaplan-Meier event-free rates at five years werecorrespondingly high. Anticoagulation compliance analysis showed only about 40% of INR readings to be withintarget ranges postoperatively; thus, the control range achieved was much greater than the desired target, as mightgenerally be expected for clinic-controlled INR. Conclusion: The On-X valve performed well in this study, confirmingthe original design intent of minimal hemolysis and low adverse event rates. copyright Copyright by ICR Publishers2006.

Institution: (McNicholas) Christiana Care Health System, Newark, DE, United States. (Ivey) Ohio Heart Institute,Cincinnati, OH, United States. (Metras) Hopital Laval, Quebec City, Que., Canada. (Szentpetery) Sentara NorfolkGeneral Hospital, Norfolk, VA, United States. (Marra) Cooper Hospital, Camden, NJ, United States. (Masters) OttawaHeart Center, Ottawa, Ont., Canada. (Dilling) St. David's Hospital, Austin, TX, United States. (Slaughter) ChristHospital, Oak Lawn, IL, United States. (Mack) Medical City, Dallas, TX, United States. (McNicholas) Cardio VascularSurgical Associates, 4745 Ogletown-Stanton Road, Newark, DE 19713-2070, United States.


The On-X heart valve: Mid-term results in a poorly anticoagulated population.

Williams M.A., van Riet S.


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Background and aim of the study: The study aim was to evaluate the clinical performance of the On-X heart valvein a socioeconomically disadvantaged population. Most patients were from an indigenous, poorly educated andgeographically dispersed segment of the population where anticoagulation therapy was generally erratic. Methods:Between 1999 an d 2004, a total of 530 valves (242 mitral valves, 104 aortic valves, 92 double valves) was implantedin 438 patients (average age 33 years; range: 3-78 years). The most common reason for surgery was rheumatic valvedisease (57%), followed by degenerative valve disease (11%) and infective endocarditis (9%). Follow up was 95%complete for a total of 746 patient-years (pt-yr). Among the patient population, 40% were either not anticoagulatedor were unsatisfactorily anticoagulated. Results: Hospital mortality was 2.3%, and none of the hospital deaths wasvalve-related. Mean (+/- SE) actuarial survival (including hospital deaths) at four years was: AVR 73.8 +/- 8.1%, MVR83.4 +/- 5.7% and DVR 60.9 +/- 10.3%. Linearized rates (for AVR, MVR and DVR, respectively) for late complications(%/ pt-yr) were: bleeding events 0.6, 1.0, and 2.3; thrombosis 0.0, 0.2, and 0.0; endocarditis 0.6, 1.0, and 2.3;paravalvular leak 0.6, 0.2, and 0.0; systemic embolism 1.1, 1.5, and 3.5. Most systemic emboli were related toinfective endocarditis. Among patients there were seven uncomplicated, full-term pregnancies. Conclusion: Bearingin mind the erratic anticoagulation coverage and high incidence of infective endocarditis, the results of this studymay be regarded as encouraging. The low incidence of valve thrombosis (one case) was noteworthy. These dataalso suggest that the On-X valve may be implanted with relative safety in women wishing to have children. copyrightCopyright by ICR Publishers 2006.

Institution: (Williams, van Riet) Provincial Hospital, Port Elizabeth, South Africa. (Williams) 314 Greenacres Hospital,Port Elizabeth, Greenacres, Port Elizabeth 6045, South Africa.

12 : Journal of Thoracic and Cardiovascular Surgery. 130(3)(pp 759-764), 2005.

A randomized comparison of the MCRI On-X and CarboMedics Top Hat bileaflet mechanical replacement aorticvalves: Early postoperative hemodynamic function and clinical events.

Chambers J., Roxburgh J., Blauth C., O'Riordan J., Hodson F., Rimington H.

Objective: This study compared hemodynamic function and clinical events in consecutive patients randomlyassigned to receive a wholly supra-annular replacement valve or a valve with an intra-annular component. Methods:Fifty-two patients with an average age of 62 years (range 40-74 years) were sized for both a CarboMedics Top Hatvalve (CarboMedics Inc, Austin, Tex) and an MCRI On-X valve (Medical Carbon Research Institute, LLC, Austin, Tex)before random assignment to receive either valve type. Echocardiographic and clinical assessments were performedin the immediate postoperative period and at 1 year. Results: The mean effective orifice areas were 1.41 +/- 0.42cm2 for the Top Hat and 2.17 +/- 0.78 cm2 for the On-X (P < .0001). The mean pressure differences were 12.2 +/-4.4 mm Hg and 6.9 +/- 3.6 mm Hg, respectively (P < .0001). New York Heart Association functional class was betterwith the On-X than the Top Hat valves, but there were no differences in clinical events, regression of left ventricularmass, or measures of hemolysis. Conclusion: The partially intra-annular MCRI On-X valve was hemodynamicallysuperior to the wholly supra-annular CarboMedics Top Hat valve. However, there were no differences in early clinicaloutcomes between the two valve types. Copyright copyright 2005 by The American Association for Thoracic Surgery.

Institution: (Chambers, Roxburgh, Blauth, O'Riordan, Hodson, Rimington) Valve Study Group, Guy's and St. ThomasHospitals, London, United Kingdom. (Chambers) Cardiothoracic Centre, St. Thomas Hospital, London SE1 7EH,United Kingdom.

13 : Journal of Heart Valve Disease. 14(1)(pp 89-95), 2005

Psychoacoustic quantification of mechanical heart valve noise.

Nielsen T., Nielsen T.V., Johansen P., Hasenkam J.M., Nygaard H.


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Background and aim of the study: Mechanical heart valves produce short clicking sounds during closure. Theseclosing sounds are annoying for some patients and their partners by causing sleeping disorders or socialembarrassment. Various methods for measuring the sounds have been developed both in vitro and in vivo usingcalculation of A-weighted sound pressure level or loudness according to ISO 532 B. The study aim was to evaluatethe relevance of different psychoacoustic parameters in the evaluation of closing sounds. Methods: Closing soundswere recorded from patients with ATS valves (n = 13), On-X valves (n = 18) and St. Jude Medical heart valveprostheses (n = 16). The sounds were recorded 5 cm above the chest of patients in a supine position, in a sound-insulated chamber. The mean peak values of loudness and sharpness were calculated and used to determine thepsychoacoustic annoyance using a modification of the Widmann formula. This was verified by a listening test forranking closing sounds of different level and sharpness by annoyance. Results: There was no statistically significantindependence between loudness difference or psychoacoustic annoyance difference and agreement among thetest persons. For the valves, loudness ranged from 0.07 to 2.57 sone, and the psychoacoustic annoyance from 0.1to 5.4. Conclusion: The results of this study showed that both sharpness and loudness have a significant influenceon annoyance from closing sounds from mechanical heart valves, and indicated that the substantial variation in theparameters may be due to individual patient physiology. copyright Copyright by ICR Publishers 2005.

Institution: (Nielsen, Nielsen, Johansen, Hasenkam, Nygaard) Department of Cardiothoracic and Vascular Surgery,Institute of Experimental Clinical Research, Aarhus University Hospital, Denmark. (Nielsen, Nielsen, Nygaard)Engineering College of Aarhus, Denmark. (Nygaard) Department of Cardiothoracic and Vascular Surgery, ResearchUnit, Skejby Sygehus, Brendstrupgaardsvej, 8200 Aarhus N, Denmark.

14 : Interactive Cardiovascular and Thoracic Surgery. 4(6)(pp 588-594), 2005.

Early clinical experience with the On-X prosthetic heart valve.

Ozyurda U., Akar A.R., Uymaz O., Oguz M., Ozkan M., Yildirim C., Aslan A., Tasoz R.

The study aimed to assess the performance of the On-X valve (Medical Carbon Research Institute, Austin, TX).Between December 2000 and January 2003 On-X valves were implanted in 400 patients aged 19-85 years (mean:55.6+/-16), 290 males and 210 females. There were 120 cases of aortic valve replacement (AVR), 258 mitralvalve replacement (MVR) and 22 combined aortic and mitral valve replacement (DVR). Additional procedures wereperformed in 144 patients. Patients were followed up prospectively at 3- to 6-month intervals. Mean follow-up was38.4+/-11.8 months (maximum 55.6 months). Overall hospital mortality was 3.5%. Freedom from adverse events at4 years in the study were as follows: thromboembolism, 99.1% for AVR, 98.3% for MVR and 94.7% for DVR patients;thrombosis, 100% for AVR, 99.2% for MVR and 94.7% for DVR; bleeding events, 99.1% for AVR, 99.2% for MVRand 88.8% for DVR; prosthetic endocarditis, 98.2% for AVR, 99.2% for MVR and 94.7% for DVR. Overall survival at4 years was 92+/-1%. At echocardiographical examination within 1 year of the AVR, the mean aortic valve gradientwas 12.8+/-6, 10.3+/-3, 9.0+/-4, 8.3+/-3, and 6.2+/-3 mmHg for 19, 21, 23, 25, 27/29 mm valve sizes, respectively.MVR mean gradient was 4.9+/-2, 4.5+/-1.2 and 4.0+/-0.8 mmHg for 25, 27/29, 31/33 mm valve sizes, respectively.On-X valve is a highly effective mechanical valve substitute with low morbidity and mortality and good functionalresults. copyright 2005 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.

Institution: (Ozyurda, Akar, Uymaz, Tasoz) Department of Cardiovascular Surgery, Heart Center, University ofAnkara School of Medicine, Dikimevi, Ankara, Turkey. (Oguz, Ozkan, Yildirim, Aslan) Division of CardiovascularSurgery, Private Yasam Hospital, Ankara, Turkey.


Three years' experience with the On-X Conform-X bileaflet prosthesis for 'atrialized' mitral valve replacement: Apreliminary report.


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Wippermann J., Albes J.M., Madershahian N., Breuer M., Franke U., Wahlers T.

Background and aim of the study: Positioning of a mechanical prosthesis outside the native annulus facilitates mitralvalve replacement, especially when the annulus is small and calcified, and preservation of the posterior leaflet(PML) is desired. Herein is described the authors' initial experience with a new mechanical bileaflet prosthesiscomprising a sheltered leaflet housing and a novel, modified asymmetrical sewing ring for an 'atrialized' implantationtechnique. Methods: Forty-seven patients (24 males, 23 females; mean age 65.8 +/- 10.9 years) were operatedon for isolated mitral regurgitation or combined stenosis and insufficiency. Ten of the patients underwent valvereplacement due to active endocarditis. Preoperative cardiac insufficiency was reflected by a mean NYHA class of2.6 +/- 0.7. The On-X Conform-X bileaflet mitral valve prosthesis (25/33 mm) was implanted in either an epiannular(43 patients) or intra-annular (four patients) fashion, and the PML and its chordae tendineae were preservable in33 patients (70.2%). All patients were monitored intraoperatively by transesophageal echocardiography (TEE) andpostoperatively by transthoracic echocardiography (TTE). Results: TEE and TTE exhibited excellent function withlow mean transvalvular gradients early after surgery (4.9 +/- 2.7 mmHg) and after three months (4.8 +/- 1.4 mmHg).Paravalvular leakage was not detected. Initial postoperative left ventricular (LV) function was almost identical topreoperative findings (ejection fraction: preop. 55.1 +/- 13.7%, early postop. 53.7 +/- 13.6%) and improved slightlyafter three months (60.1 +/- 6.4%). Clinically significant hemolysis was not apparent (LDH at postoperative day 7:5.3 +/- 0.8 mumol/l.s). Two patients died from multiorgan failure (4.2%) and four are currently in a reduced conditionrequiring long-term hospitalization (morbidity 8.5%). After three months all other patients were in an excellentclinical state (mean NYHA class 1.5 +/- 0.6) and being followed up as outpatients. Conclusion: Current designsof mechanical bileaflet valves require redundant space in the IV cavity for undisturbed leaflet movement. A smallannulus, marked fibrosis and calcification of the valvular apparatus can lead to an impedance of prosthetic leafletmotion. Consequently, the native leaflets are often removed. The cylindrical housing of the On-X valve sheltersalmost the entire motion of the leaflets, allowing an undisturbed function and improved transvalvular flow pattern.The newly developed asymmetrical sewing ring facilitates anchoring of the ring in an 'atrialized' fashion, while theflexibility of the cuff adapts to all native ring diameters larger than 25 mm. copyright Copyright by ICR Publishers2005.

Institution: (Wippermann, Madershahian, Breuer, Franke, Wahlers) Department of Cardiothoracic and VascularSurgery, University Hospital Jena, 07740 Jena, Germany. (Albes) Heart-Centre-Brandenburg, Bernau, Germany.

16 : Journal of Heart Valve Disease. 13(5):823-30, 2004 Sep.

Doppler assessment of mechanical aortic valve prostheses: effect of valve design and size of the aorta.

Mascherbauer J. Schima H. Maurer G. Baumgartner H.

BACKGROUND AND AIM OF THE STUDY: Discrepancies between Doppler and catheter gradients have beenreported for bileaflet aortic valve prostheses. Whether modifications in geometric design of newly developed bileafletvalves lead to a different Doppler-catheter gradient relationship has not been evaluated. Variable results have beenreported for tilting-disc prostheses. In addition, the effect of aortic size on the Doppler-catheter gradient relationshipremains unclear. METHODS: Various sizes of On-X and Edwards Mira (identical with Sorin Bicarbon) bileaflet valvesand Sorin Allcarbon tilting-disc aortic valves (19-25 mm) were studied in a pulsatile flow model. Doppler and cathetergradients were measured simultaneously. Aortic diameters between 1.8 and 4 cm were evaluated. RESULTS:Correlation between Doppler and catheter gradients was excellent (r = 0.98-0.99 for peak and mean gradients), butin bileaflet valves Doppler significantly overestimated the corresponding catheter gradients as reflected by slopesof the regression lines (1.57-1.8). In the range of relevant gradients > or = 10 mmHg, Doppler exceeded cathetergradients by 40 +/- 17% (peak) and 39 +/- 16% (mean) in Mira valves, and by 46 +/- 19% (peak) and 43 +/- 14%(mean) in On-X valves. In the Sorin tilting-disc valve, Doppler accurately reflected catheter gradients (slopes of


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regression lines 1.05-1.14). The aortic diameter significantly influenced results in only tilting-disc valves, but inabsolute terms the effect was clinically less relevant. CONCLUSION: Discrepancies between Doppler and cathetergradients are common to all bileaflet valves, regardless of their specific geometric design, whereas tilting-disc valvesmust be considered individually. The influence of aortic size on the Doppler-catheter gradient relationship appearsclinically to be less relevant in prosthetic valves.

MEDLINEAuthors Full Name: Mascherbauer, Julia. Schima, Heinrich. Maurer, Gerald. Baumgartner, Helmut.

Institution: Department of Cardiology, University of Vienna , Vienna General Hospital, Austria.

17 : Journal of Cardiac Surgery. 19(5)(pp 410-414), 2004.

A comparison of mechanical valve performance in a poorly anticoagulated community.

Williams M.A., Crause L., Van Riet S.

Background: This study was undertaken to evaluate the clinical performance of the Carbomedics, Medtronic Halland On-X valves in the challenging setting of a Third World population with incomplete anticoagulation coverage.Methods: In the Carbomedics group 140 valves were implanted in 126 patients (aortic 30, mitral 82, and aortic andmitral 14), 39% were adequately anticoagulated. Follow-up was 89% complete for a total of 216 patient-years. In theMedtronic Hall series 224 valves were implanted in 198 patients (aortic 50, mitral 122, and aortic and mitral 26), 39%were adequately anticoagulated. Follow-up was 93% complete for a total of 459 patient-years. In the On-X series252 valves were implanted in 200 patients (aortic 44, mitral 104, and aortic and mitral 52), 58% were adequatelyanticoagulated. Follow-up was 94% complete for a total of 2217 patient-years. Results: Hospital mortality was 2.4%(3 patients) in the Carbomedics group, 3.9% (9 patients) in the Medtronic Hall group, and 2.0% in the On-X group.None of the hospital deaths were valve-related. The linearized rates for late complications in the mitral position(percent per patient-year) were, respectively, for the Carbomedics (CM), the Medtronic Hall (MH), and On-X valves- thromboembolism: 1.4 (CM), 1.1 (M.H.); 0.0 (On-X); bleeding: 0.0 (CM), 0.4 (MH); 0.0 (On-X); thrombosis: 6.5(CM), 2.0 (MH); 0.0 (On-X). In the aortic position, the linearized rates of late complications were, respectively -thromboembolism: 0.0 (CM), 1.6 (MH); 2.2 (On-X); bleeding: 1.3 (CM), 1.0 (MH); 0.0 (On-X); thrombosis: 1.3 (CM),0.0 (MH); 0.0 (On-X). Conclusions: There were no significant differences in the performance of the three valvesin the aortic position. In the mitral position the linearized rate of valve thrombosis was significantly higher in theCarbomedics group (p = 0.002).

Institution: (Williams, Crause, Van Riet) Department of Cardiothoracic Surgery, Provincial Hospital, Port Elizabeth,South Africa. (Williams) 314 Greenacres Hospital, Greenacres, 6045 Port Elizabeth, South Africa.

18 : Circulation. 107(18)(pp 2303-2306), 2003.

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

Bottio T., Casarotto D., Thiene G., Caprili L., Angelini A., Gerosa G.

Background - Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complicationpreviously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrencesobserved in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. Methods andResults - At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valveprostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late.Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent


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a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explantedprostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylacticreplacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failurein any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1hemorrhage, and 1 paravalvular leak. Conclusion - These catastrophes prompted us to interrupt the implantationprogram, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its highrisk of structural failure.

Institution: (Bottio, Casarotto, Caprili, Gerosa) Department of Cardiovascular Surgery, University of Padua MedicalSchool, Padua, Italy. (Thiene, Angelini) Department of Pathology, University of Padua Medical School, Via A. Gabelli,61, 35121 Padova, Italy.

19 : Current Problems in Cardiology. 28(7)(pp 413-480), 2003.

Surgical Options in Young Adults with Aortic Valve Disease.

Svensson L.G., Blackstone E.H., Cosgrove III D.M.

The ideal valve or ideal procedure for patients requiring aortic valve surgery has not been developed. It would seemintuitive that an aortic valve replacement with an allograft-a functioning human valve-would be ideal; however, thisis not entirely the case because of the risk of late calcification, which is probably related to the ischemia time orrejection of the valve. Thus, the choice of valve procedure in a young patient should depend on patient preference,pathology, comorbid disease, and the surgeon's skill with the valve, durability weighed against the disadvantagesof anticoagulation, and risk of insertion and reoperation; until the ideal valve is developed-if ever.

Institution: (Svensson, Blackstone, Cosgrove III) Dept. of Thorac./Cardiovasc. Surg., Cleveland Clinic Foundation,Cleveland, OH, United States. (Svensson) Cleveland Clinic Foundation, Dept. of Thorac./Cardiovasc. Surg., 9500Euclid Avenue, Cleveland, OH 44195, United States.

20 : Artificial Organs. 26(1):32-9, 2002 Jan.

In vitro investigation of opening behavior and hydrodynamics of bileaflet valves in the mitral position.

Feng Z. Nakamura T. Fujimoto T. Umezu M.

The performance of four 25 mm bileaflet valves of different designs was evaluated in the mitral position of our ownpulse simulator. With the aid of a high-speed video camera, it was demonstrated that both the St. Jude Medical (SJM)valve (Hemodynamic Plus [HP] Series, St. Jude Medical, Inc., St. Paul, MN, U.S.A.) and the CM valve (CarboMedics,Inc., Austin, TX, U.S.A.) were able to open fully and that the CM valve fluttered much more vigorously at the fullyopen position than did the SJM HP valve. Conversely, neither the ATS valve (ATS Medical, Inc., Minneapolis, MN,U.S.A.) nor the On-X valve (Medical Carbon Research Institute, Austin, TX, U.S.A.) exhibited movement to a fullyopen configuration. The overall average opening angles of the ATS and the On-X, on 3, 4, and 5 L/min flow ratefor a heart rate of 70 bpm and 5, 6, and 7 L/min for 100 bpm, were 74.8 degrees and 81.6 degrees, respectively,whereas their design opening angles were 85 degrees and 90 degrees. Pressure drops across the CM and the ATSwere consistently higher than those of the On-X and the SJM HP. Closing volumes for all the valves were below 8%for a heart rate of 70 bpm. This in vitro investigation yielded the following conclusions: The ATS and On-X valvesare not able to open fully in the mitral position, but this does not impair their normal function; both a larger orificediameter and a large opening angle can decrease the pressure drop; in general, the On-X valve achieves its designgoals in this experiment (i.e., it produces a lower pressure drop and lower closing volume by virtue of its large orificeand high-profile design); however, the hinge flow in the non-fully open state should be investigated further.


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MEDLINEAuthors Full Name: Feng, Zhonggang. Nakamura, Takao. Fujimoto, Tetsuo. Umezu, Mitsuo.

Institution: Department of Bio-System Engineering, Faculty of Engineering, Yamagata University, Yonezawa, [email protected]

21 : Annals of Thoracic Surgery. 74(4)(pp S1312-S1317), 2002.

The On-X prosthetic heart valve at five years.

Moidl R., Simon P., Wolner E.

Background. Multicenter clinical trials were conducted in Europe and North America to evaluate the performanceof the On-X bileaflet heart valve prosthesis (Medical Carbon Research Institute, Austin, TX). Methods. A total of532 patients underwent implantation, 303 for aortic valve replacement (AVR) and 229 for mitral valve replacement(MVR), at 20 centers from September 1996 to July 2001. The study followed the guidelines of the AATS/STS. Meanfollow-up was 23 months (total 1024 patient-years; maximum 5 years). Poolability analysis was performed to showthe equivalence of the populations. Results. Patients and results were found to be similar and poolable. Freedomfrom adverse events at 2 years in the study were as follows: thromboembolism, 96.0% for AVR patients and 96.3%for MVR; thrombosis, 100% for AVR and 100% for MVR; bleeding events, 96.6% for AVR and 95.7% for MVR;and overall mortality, 95.2% for AVR and 92.4% for MVR. Median lactate dehydrogenate levels were in the normalrange for AVR and MVR patients at all intervals. At 1 year, AVR echocardiographic results for the 19 to 25 valves,respectively, ranged from 1.5 to 2.8 cm2 for effective orifice area and 9.2 to 4.7 mm Hg for mean gradient, and MVReffective orifice area by pressure half-time was 2.8 cm2 and mean gradient was 4.2 mm Hg. Conclusions. The twotrials have given similarly excellent results for the On-X valve. copyright 2002 by The Society of Thoracic Surgeons.

Institution: (Moidl, Simon, Wolner) Department of Cardiothoracic Surgery, University of Vienna, Vienna, Austria. (Moidl) Department of Cardiothoracic Surgery, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna,Austria.

22 : Artificial Organs. 26(10):872-8, 2002 Oct.

Mock loop testing of On-x prosthetic mitral valve with Doppler echocardiography.

Verdonck PR. Dumont K. Segers P. Vandenberghe S. Van Nooten G.

Previous in vitro testing (mainly in aortic position) and clinical experience (often based on Doppler echocardiographicobservations) demonstrated an excellent hemodynamic behavior of the On-X valve. However, integrative studiesincluding simultaneous hemodynamic pressure and flow measurements and Doppler echocardiography are lacking.Using our computer-controlled mock loop system, two samples of the Mitral 27/29 and one sample of the Conform-X Mitral 25/33 are tested in mitral position. Data include transvalvular pressure gradient and flow as well astransthoracic Doppler echocardiography. The valves are tested under three pressure conditions (ventricular systolicpressure of 100, 130, and 160 mm Hg) at three different heart rates (60, 100, and 140 beats/min). In addition,ventricular pressure conditions simulating fibrillation are imposed. Both valve types show similar hydrodynamiccharacteristics and have an effective orifice area of 2.1 cm2 and a performance index of 0.56 for a cardiac outputof 3.5 L/min. Regurgitant volumes remain below 6 ml.

MEDLINEAuthors Full Name: Verdonck, Pascal R. Dumont, Kris. Segers, Patrick. Vandenberghe, Stijn. VanNooten, Guido.

Institution: IBiTech, Institute of Biomedical Technology, Ghent University, Belgium. [email protected]


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Early clinical experience with the On-X prosthetic heart valve.

Laczkovics A., Heidt M., Oelert H., Laufer G., Greve H., Pomar J.L., Mohr F.W., Haverich A., Birnbaum D.,Regensburger D., Palatianos G., Wolner E.

Background and aim of the study: The study was designed to investigate the clinical performance of the On-Xprosthetic heart valve in a multicenter experience. Methods: Between September 1996 and September 1999, 301patients (56% males) underwent isolated On-X valve replacement (184 isolated aortic (AVR), 117 isolated mitral(MVR)) at 11 European centers under a standardized protocol. Average age at implant was 60.2 years. Office orhospital follow up was required by the protocol; average follow up on all patients was 11 months. Results: Thirty-day mortality in the study was 2.2% for AVR and 6.0% for MVR, with valve-related mortality of 0.5% for AVR. Therewere eight late deaths (0.7%/pt-yr AVR and 2.3%/pt-yr MVR). Two of these deaths were sudden, and thus possiblyvalve-related (one AVR, one MVR). Early total valve-related morbidity was 3.5% for AVR and 2.6% for MVR. Intotal, 13 thromboembolic events occurred; one early event in AVR resulted in death (0.5%), and one transient earlyevent occurred in MVR (0.9%). There were 11 late events (seven AVR (1.7%/pt-yr) and four MVR (1.8%/pt-yr)), fora two-year freedom from thromboembolism of 96.6% after AVR and 97.1% after MVR. Three late bleeding eventsoccurred, all after AVR (0.7%/pt-yr and 98.9% free at two years). Major paravalvular leaks requiring reoperationoccurred on two occasions early (one AVR (0.5%), one MVR (0.8%)) and once late in MVR (0.5%/pt-yr). Lateminor, untreated paravalvular leaks occurred in three AVR patients (0.7%/pt-yr) and in one MVR patient (0.5%/pt-yr). Prosthetic endocarditis occurred four times (two AVR (0.5%/pt-yr), two MVR (0.9%/pt-yr)), all within the first 12months of surgery. Actuarial freedom from all valve-related events at two years was 88.7% for AVR and 88.1% forMVR. NYHA class was improved in 75.8% of AVR patients and 70.6% of MVR patients at two years after surgery.Conclusion: These early results indicate that the On-X valve provides satisfactory clinical outcome in the immediatepostoperative period, and that the valve is both safe and effective.

Institution: (Laczkovics, Heidt, Oelert, Laufer, Greve, Pomar, Mohr, Haverich, Birnbaum, Regensburger, Palatianos,Wolner) Kliniken Bergmannsheil, Burkle-de-la-Camp-Platz 1, D-44789 Bochum, Germany.

24 : Computational fluid dynamics study of a protruded-hinge bileaflet mechanical heart valve.

Wang J., Yao H., Lim C.J., Zhao Y., Yeo T.J.H., Hwang N.H.C.

Journal of Heart Valve Disease. 10(2)(pp 254-263), 2001.

Background and aim of the study: Following clinical experience with the Medtronic ParallelTM bileaflet mechanicalheart valve, considerable interest has been shown in investigating fluid mechanics inside the hinge socket. Mostof these studies involved hinges that are recessed into the valve housing, such as the St. Jude Medical (SJM),CarboMedics, Sorin and On-X bileaflet mechanical heart valves. The aim of this study was to investigate the flowfields of a protruded hinge under steady flow conditions, with the occluder in its fully open position. Computationalfluid dynamics (CFD) simulation using the Fluent 4.4.7 commercial solver was applied in this investigation. Thisprotruded hinge mechanism for pivoting the occluder is an in-house design from the Cardiovascular DynamicsLaboratory, Nanyang Technological University. Methods: The Fluent 4.4.7 code was run on a Silicon Graphic Inc.computer (4-CPUx185MHz) in the CFD simulation. A body-fitted coordinates (BFC) grid was generated to coverthe entire valvular flow domain, including the interior of the hinge and leaflet. Clearance between the leaflet andpivot housing was 50-70 mum. In the vicinity of the protruded hinge, mesh cells were small compared with hingedimensions. A power law distribution of grid points was applied to optimize the number of cells used to clusterthe entire flow field. The overall computational flow domain of the valve channel, including the floating leaflet andimmersed hinge, was O170,000 cells in total. Inside the hinge socket, O10,000 cells were generated. A comparativemodel with recessed hinge that resembled the SJM valve hinge design was modeled. Due to geometric difficulties,


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an unstructured grid scheme was applied. Great attention was focused within the hinge pocket, in particular to theclearance between the hinge pivot and leaflet. A total of 2 million cells was generated for the whole computationalflow domain. Results: Under steady flow conditions, with the leaflet fixed in an open position, the protruded hingedesign yielded a pair of small vortices that formed behind the stoppers. A low-magnitude velocity was observedinside the hinge clearance. Vortices developed behind the protruded stopper. Migrating flow was noted beneaththe leaflet clearance as a result of pressure difference across the leaflet. For the recessed hinge design, reverseflow dominated the inside of the hinge socket, and developed into a pair of vortices at high Reynolds number.Conclusion: The protruded hinge mechanism was designed to expose the overall hinge region to the mainstreamflow for a positive washing effect. Flow in this protruded hinge design is, in general, found to be three-dimensional.Initial results under steady flow conditions showed low laminar and turbulent shear stress, while the hinge clearancewas well washed.

Institution: (Wang, Yao, Lim, Zhao, Yeo, Hwang) Cardiovascular Dynamics Laboratory, School of Mechanical/Prod.Engr., Nanyang Technological University, Singapore 639798, Singapore.


Examination of hemolytic potential with the On-X(R) prosthetic heart valve.

Birnbaum D., Laczkovics A., Heidt M., Oelert H., Laufer G., Greve H., Pomar J.L., Mohr F., Haverich A.,Regensburger D.

Background and aim of the study: Mechanical valves are known to produce chronic, subclinical hemolysis inmost patients. Generally, haptoglobin is reduced to below normal in most patients, while lactate dehydrogenase(LDH) is increased to as much as 200% above the upper normal, sometimes resulting in anemia. The study wasdesigned to investigate the clinical hemolysis of the On-X(R) prosthetic heart valve in a multicenter experience witha standard protocol and a single clinical laboratory. Methods: Between September 1996 and August 1998, 248patients underwent isolated valve replacement at 10 European centers. Blood samples were collected from thesepreoperatively and at 3-6 months and one year postoperatively. All samples were analyzed at a central laboratory,thus assuring poolability of the data. In total, 151 patients were tested at 3-6 months, and 62 at one year. Bloodparameters measured were LDH, haptoglobin, hematocrit, total hemoglobin, red cell count and reticulocyte count.Paired analysis was used to compare preoperative baseline values with 36-month and one-year values. Data wereanalyzed with regard to both valve position and size. Results: At 3-6 months and one year after surgery, averagevalues for hematocrit, hemoglobin, red cell count and reticulocyte count were all near the center of the normal range,regardless of valve position or size. Statistically significant increases in red cell count and decreases in reticulocytecount occurred after both aortic valve replacement (AVR) and mitral valve replacement (MVR). These changes wereof no clinical importance, but indicate that anemia has not occurred in these patients. At 3-6 months, haptoglobinwas reduced to below normal in 86% of both AVR and MVR patients; this also occurred after one year and wasstatistically significant. Postoperatively, the mean LDH value in AVR was 228 U/1 (91% of upper normal, 250 U/l)at 3-6 months, and 246 U/l (98% of upper normal) at one year. In MVR, these LDH values were 271 U/l (108% ofupper normal) and 265 U/l (106% of upper normal). Conclusions: These results indicate that the On-X valve causeslower levels of chronic hemolysis in the immediate postoperative period and up to one year after surgery, especiallywhen compared with reports of LDH elevations up to 200% of upper normal. Hemolytic anemia has not occurredin this patient population.

Institution: (Birnbaum) Universitatsklinikum Regensburg, Germany. (Laczkovics) Klinikum Bergmannsheil, Bochum,Germany. (Heidt) Universitatsklinikum Giessen, Germany. (Oelert) Universitats-Klinik Mainz, Germany. (Laufer)Allgemeines Krankhs. der Stadt Wien, Austria. (Greve) Klinikum Krefeld, Germany. (Pomar) Hospital Clinico deBarcelona, Spain. (Mohr) Herzzentrum Leipzig, Germany. (Haverich) Medizinische Hochschule Hanover, Germany.


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(Regensburger) Klin. der Chrstn.-Albrechts-Univ., Kiel, Germany. (Birnbaum) University Hospital, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany.


A comparison of the classical and modified forms of the continuity equation in the on-X prosthetic heart valve inthe aortic position.

Chambers J., Ely J.

Background and aim of the study: The use of echocardiography to determine prosthetic valve hemodynamics hasbecome generally accepted; however, there are still many differing methodologies in use. The continuity equation,which uses the ratio of the subaortic and transaortic velocity-time integrals for determining aortic effective orificearea (EOA), has been established as an accurate method. Another method using the more easily measured peakvelocities in ratio has also been employed. These methods were compared to determine if the simpler methodgave equivalent results. Methods: Early postoperative echocardiographic data on prosthetic valves from the MCRIMulticenter Trial were used to compare the two methods of calculating EOA (A2). Results using the two methodswere compared by paired t-tests, the Wilcoxon signed rank test, regression and Bland-Altman analysis. Results:Despite a good correlation between the two methods (r = 0.91), results were different when compared by a pairedt-test. On average, results by the modified method were 0.2 cm2 lower, but in 28% of cases they were in fact higherthan the classical method. Conclusion: The modified continuity equation based on the peak velocity ratio does notgive the same result as the classical formula based on the velocity-time ratio. The modified method cannot reliablybe substituted for the classical method in normally functioning On-X valves.

Institution: (Chambers) Adult Echocardiography, Guy's and St. Thomas' Hospitals, London, United Kingdom. (Ely)Medical Carbon Research Institute, LLC (MCRI), Austin, TX, United States. (Chambers) Guy's and St. Thomas'Hospital Trust, Lambeth Palace Road, London SE1 7FH, United Kingdom.

27 : Cor Europaeum - European Journal of Cardiac Interventions. 8(3)(pp 111-114), 2000.

Clinical and hemodynamic performance of the On-X bileaflet heart valve.

Dohmen G., Prufer D., Dahm M., Guth S., Moersig W., Choi Y.H., Oelert H.

Purpose: In order to optimize flow characteristics, the On-X bileaflet valve combines various new characteristics suchas elongated orifice and flared orifice inlet with potentiality and strength of pure, unalloyed carbon. Study aim was theevaluation of postoperative hemodynamics of this prosthesis by echocardiography and of its clinical performance.Methods: 27 consecutive patients who received On-X aortic heart valves in our institution were included in thisstudy, 7 patients had concomitant cardiac procedures. Results of flow characteristics derived from echocardiographyperformed prior to discharge as well as 6 and 12 months postoperatively were analyzed. Results: No patient diedperioperatively or during followup period. No thromboembolic complications in the early postoperative period wereobserved, 2 patients reported TIA at the 12 month control. Echocardiographic results concerning effective orificearea (EOA) and pressure gradients showed superior hemodynamic performance. Conclusions: Implantation of theOn-X bileaflet valve is safe and feasible with low thromboembolic risk. Hemodynamic performance is excellent.

Institution: (Dohmen, Prufer, Dahm, Guth, Moersig, Choi, Oelert) Klinik Herz- Thorax- Gefasschirurgie, JohannesGutenberg-Universitat Mainz, Langenbeckstrasse 1, D-55131 Mainz, Germany.

28 : Proceedings of the Institution of Mechanical Engineers. Part H - Journal of Engineering in Medicine. 214(1):121-8,2000.


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A new method for quantitative evaluation of perceived sounds from mechanical heart valve prostheses.

Johansen P. Riis C. Hasenkam JM. Paulsen PK. Nygaard H.

Closing clicks from mechanical heart valve prostheses are transmitted to the patient's inner ear mainly in two differentways: as acoustically transmitted sound waves, and as vibrations transmitted through bones and vessels. Thepurpose of this study was to develop a method for quantifying what patients perceive as sound from their mechanicalheart valve prostheses via these two routes. In this study, 34 patients with implanted mechanical bileaflet aortic andmitral valves (St Jude Medical and On-X) were included. Measurements were performed in a specially designedsound insulated chamber equipped with microphones, accelerometers, preamplifiers and a loudspeaker. The closingsounds measured with an accelerometer on the patient's chest were delayed 400 ms, amplified and played backto the patient through the loudspeaker. The patient adjusted the feedback sound to the same level as the 'real-time' clicks he or she perceived directly from his or her valve. In this way the feedback sound energy includes boththe air- and the bone-transmitted energies. Sound pressure levels (SPLs) were quantified both in dB(A) and in theloudness unit sone according to ISO 532B (the Zwicker method). The mean air-transmitted SPL measured close tothe patient's ear was 23 +/- 4 dB(A). The mean air- and bone-transmitted sounds and vibrations were perceived bythe patients as an SPL of 34 +/- 5 dB(A). There was no statistically significant difference in the perceived sound fromthe two investigated bileaflet valves, and no difference between aortic and mitral valves. The study showed that thepresented feedback method is capable of quantifying the perceived sounds and vibrations from mechanical heartvalves, if the patient's hearing is not too impaired. Patients with implanted mechanical heart valve prostheses seemto perceive the sound from their valve two to three times higher than nearby persons, because of the additionalbone-transmitted vibrations.

MEDLINEAuthors Full Name: Johansen, P. Riis, C. Hasenkam, J M. Paulsen, P K. Nygaard, H.

Institution: Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Skejby Sygehus,Denmark.


Comparison of On-X and SJM hp bileaflet aortic valves.

Walther T., Falk V., Tigges R., Kruger M., Langebartels G., Diegeler A., Autschbach R., Mohr F.W.

Background and aim of the study: The study aim was to evaluate the hemodynamic function after aortic valvereplacement (AVR) using the On-X valve, in comparison with St. Jude Medical (SJM) HP bileaflet valves. Methods:Patients received either the On-X (n = 20) or SJM HP prosthesis (n = 20) for AVR. The control (SJM HP) groupwas computer-matched with the On-X group for age, gender, aortic stenosis as underlying disease, body surfacearea, NYHA functional class, left ventricular size, mass and function, transvalvular pressure gradients and cardiacindex. Mean implanted valve size was 23.5 mm (three 21 mm, ten 23 mm, six 25 mm, one 27 mm) in bothgroups. All patients underwent postoperative, and six- and 12-month follow up echocardiography. Results: The intra-and postoperative course was uneventful in all patients. There were no significant differences in cross-clamp andcardiopulmonary bypass times, intensive care unit stay, in-hospital stay and postoperative NYHA functional class.Two patients (both On-X) had paravalvular leakage postoperatively and at follow up. Five patients in the controlgroup had additional myocardial revascularization. Transvalvular flow velocities were 2.38 +/- 0.3 versus 2.38 +/-0.4 m/s (p = NS) postoperatively, and 2.08 +/- 0.2 versus 2.22 +/- 0.3 m/s (p = NS) at one year follow up for On-X and SJM HP valves, respectively. Maximum pressure gradients were 16.9 +/- 6.0 versus 18.5 +/- 8.0 mmHg (p= NS) postoperatively and 14.0 +/- 3.7 versus 16.5 +/- 5 7 mmHg (p = NS) at one year for the two valve types,respectively. A relatively pronounced transvalvular reflux was diagnosed for On-X valves. Conclusion: Atone yearafter implantation, the On-X bileaflet prosthesis is equally suited for AVR in comparison with the 'standard' therapy


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(SJM HP). Exact sizing requires some experience. There were no significant differences between the two prostheseswith regard to hemodynamic parameters either postoperatively or at one-year follow up. Long-term prospectiverandomized studies yet have to be carried out.

Institution: (Walther, Falk, Tigges, Kruger, Langebartels, Diegeler, Autschbach, Mohr) Department of CardiacSurgery, Heart Center, University of Leipzig, Germany. (Walther) Universitat Leipzig, Herzzentrum, Klinik furHerzchirurgie, Russenstrasse 19, 04289 Leipzig, Germany.


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