title: Clinical event rates with the On-X bileaflet mechanical heart valve: a multicenter experience with follow-up to 12 years.
abstract: OBJECTIVE
  The aim of the study was to establish clinical event rates for the On-X bileaflet mechanical heart valve (On-X Life Technologies Inc, Austin, Tex) using an audit of data from the 3 centers within Europe with the longest history of implanting.
  
  
  METHODS
  All patients receiving the On-X valve between March 1, 1998, and June 30, 2009, at 3 European centers were studied. Data were collected using questionnaire and telephone surveys augmented by outpatient visits and examination of clinical records.
  
  
  RESULTS
  There were 691 patients, with a mean age of 60.3 years, who received 761 valves in total: 407 mitral valve replacements, 214 aortic valve replacements, and 70 aortic + mitral valve replacements (dual valve replacement). Total follow-up was 3595 patient-years, with a mean of 5.2 years (range, 0-12.6 years). Early (≤ 30 days) mortality was 5.4% (mitral valve replacement), 0.9% (aortic valve replacement), and 4.3% (dual valve replacement). Linearized late (>30 days) mortality expressed per patient-year was 3.6% (mitral valve replacement), 2.2% (aortic valve replacement), and 4.1% (dual valve replacement), of which valve-related mortality was 0.5% (mitral valve replacement), 0.2% (aortic valve replacement), and 1.8% (dual valve replacement). Late linearized thromboembolism rates were 1.0% (mitral valve replacement), 0.6% (aortic valve replacement), 1.8% (dual valve replacement). Bleeding rates were 1.0% (mitral valve replacement), 0.4% (aortic valve replacement), and 0.9% (dual valve replacement). Thrombosis rates were 0.1% (mitral valve replacement), 0% (aortic valve replacement), and 0.3% (dual valve replacement). Reoperation rates were 0.6% (mitral valve replacement), 0.2% (aortic valve replacement), and 1.2% (dual valve replacement).
  
  
  CONCLUSIONS
  The On-X valve has low adverse clinical event rates in longer-term follow-up (mean 5.2 years and maximum 12.6 years).
authors.affiliation: Guy's and St Thomas Hospitals, London, England. john.chambers@gstt.nhs.uk
authors.forename: John B
authors.initials: JB
authors.lastname: Chambers
authors.forename: Jose L
authors.initials: JL
authors.lastname: Pomar
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Mestres
authors.forename: George M
authors.initials: GM
authors.lastname: Palatianos
mesh_terms: D000328:Adult; D000368:Aged; D005060:Europe; D005260:Female; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation* / Q000401:mortality; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality / Q000601:surgery; D011474:Prosthesis Design; D012086:Reoperation; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome