title: The On-X prosthetic heart valve at five years.
abstract: BACKGROUND
  Multicenter clinical trials were conducted in Europe and North America to evaluate the performance of the On-X bileaflet heart valve prosthesis (Medical Carbon Research Institute, Austin, TX).
  
  
  METHODS
  A total of 532 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. Mean follow-up was 23 months (total 1024 patient-years; maximum 5 years). Poolability analysis was performed to show the equivalence of the populations.
  
  
  RESULTS
  Patients and results were found to be similar and poolable. Freedom from 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 normal range 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 MVR effective orifice area by pressure half-time was 2.8 cm2 and mean gradient was 4.2 mm Hg.
  
  
  CONCLUSIONS
  The two trials have given similarly excellent results for the On-X valve.
authors.affiliation: reinhard.moidl@akh-wien.ac.at
authors.forename: Reinhard
authors.initials: R
authors.lastname: Moidl
authors.forename: Paul
authors.initials: P
authors.lastname: Simon
authors.forename: Ernst
authors.initials: E
authors.lastname: Wolner
mesh_terms: D000328:Adult; D000368:Aged; D001021:Aortic Valve; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D011474:Prosthesis Design; D013923:Thromboembolism / Q000209:etiology; D013927:Thrombosis / Q000209:etiology; D016896:Treatment Outcome
chemical_list: D007770:L-Lactate Dehydrogenase