title: Clinical outcomes with the Hancock II bioprosthetic valve.
abstract: BACKGROUND
  The Hancock II bioprosthetic valve, which was first introduced to clinical use in 1978, differs from its predecessor in several ways. This study was designed to evaluate the durability and outcomes with this valve in patients who had isolated aortic or mitral valve replacements.
  
  
  METHODS
  From 1991 to 1999, 459 patients underwent aortic valve replacement and 138 patients underwent mitral valve replacement with the Hancock II bioprosthesis (Medtronic Inc, Minneapolis, MN). The mean age was 73.2 +/- 0.4 and 72.6 +/- 0.8 years in the aortic and mitral groups, respectively. Most patients were in New York Heart Association Class III or IV (50% aortic group and 69% mitral group) and concomitant coronary artery bypass was performed in 49.4% and 52.8% of patients, respectively. Patients were assessed annually and follow-up was up to 129 months in the aortic group and 100 months in the mitral group.
  
  
  RESULTS
  At 8 years, actuarial survival was 52% +/- 5% in the aortic group and 57% +/- 8% in the mitral group. Furthermore, the actuarial freedom from structural failure necessitating reoperation was 99% +/- 0.5% in the aortic group and 98% +/- 2% in the mitral group, and the actuarial freedom from repeat valve surgery due to all causes was 97% +/- 2% and 96% +/- 2%, respectively. Actuarial freedom from thromboembolic events was 89% +/- 2% in the aortic group and 90% +/- 5% in the mitral group.
  
  
  CONCLUSIONS
  The Hancock II valve has excellent midterm durability and clinical performance in older patients.
authors.affiliation: Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, Canada. rmasters@ottawaheart.ca
authors.forename: Roy G
authors.initials: RG
authors.lastname: Masters
authors.forename: Michel
authors.initials: M
authors.lastname: Haddad
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Pipe
authors.forename: John P
authors.initials: JP
authors.lastname: Veinot
authors.forename: Thierry
authors.initials: T
authors.lastname: Mesana
mesh_terms: D000206:Actuarial Analysis; D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis / Q000706:statistics & numerical data*; D002423:Cause of Death; D004696:Endocarditis / Q000453:epidemiology; D019544:Equipment Failure Analysis; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery*; D006470:Hemorrhage / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008943:Mitral Valve / Q000601:surgery*; D017755:Prosthesis Fitting; D012086:Reoperation; D012189:Retrospective Studies; D017678:Sex Distribution; D015996:Survival Rate; D013923:Thromboembolism / Q000453:epidemiology; D013927:Thrombosis / Q000453:epidemiology; D016896:Treatment Outcome