title: Late incidence and determinants of reoperation in patients with prosthetic heart valves.
abstract: OBJECTIVE
  Reoperation is a relatively common event in patients with prosthetic heart valves, but its actual occurrence can vary widely from one patient to another. With a focus on bioprosthetic valves, this study examines risk factors for reoperation in a large patient cohort.
  
  
  METHODS
  Patients (N=3233) who underwent a total of 3633 operations for aortic (AVR) or mitral valve replacement (MVR) between 1970 and 2002 were prospectively followed (total 21,179 patient-years; mean 6.6+/-5.0 years; maximum 32.4 years). The incidence of prosthetic valve reoperation and the impact of patient- and valve-related variables were determined with actual and actuarial methods.
  
  
  RESULTS
  Fifteen-year actual freedom from all-cause reoperation was 94.1% for aortic mechanical valves, 61.4% for aortic bioprosthetic valves, 94.8% for mitral mechanical valves, and 63.3% for mitral bioprosthetic valves. In both aortic and mitral positions, current bioprosthesis models had significantly better durability than discontinued bioprostheses (15-year reoperation odds-ratio 0.11+/-0.04; P<0.01 for aortic, and 0.42+/-0.14; P=0.009 for mitral). Current bioprostheses were significantly more durable in the aortic position than in the mitral position (14.3+/-6.8% more freedom from 15-year reoperation; (P=0.018)). Older age was protective, but smoking was an independent risk factor for reoperation after bioprosthetic AVR and MVR (hazard ratio for smoking 2.58 and 1.78, respectively). In patients with aortic bioprostheses, persistent left ventricular hypertrophy at follow-up and smaller prosthesis size predicted an increased incidence of reoperation, while this was not observed in patients with mitral bioprostheses.
  
  
  CONCLUSIONS
  These analyses indicate that current bioprostheses have significantly better durability than discontinued bioprostheses, reveal a detrimental impact for smoking after AVR and MVR, and indicate an increased reoperation risk in patients with a small aortic bioprosthesis or with persistent left ventricular hypertrophy after AVR.
authors.affiliation: Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Suite 3403, Ottawa, Ont., Canada K1Y 4W7. mruel@ottawaheart.ca
authors.forename: Marc
authors.initials: M
authors.lastname: Ruel
authors.forename: Alexander
authors.initials: A
authors.lastname: Kulik
authors.forename: Fraser D
authors.initials: FD
authors.lastname: Rubens
authors.forename: Pierre
authors.initials: P
authors.lastname: Bédard
authors.forename: Roy G
authors.initials: RG
authors.lastname: Masters
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Pipe
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Mesana
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D001830:Body Surface Area; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000150:complications; D005260:Female; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects