title: Mechanical versus bioprosthetic valve replacement in middle-aged patients.
abstract: OBJECTIVE
  The current trend towards decreasing the age for selection of a tissue over a mechanical prosthesis has led to a dilemma for patients aged 50-65 years. This cohort study examines the long-term outcomes of mechanical versus bioprosthetic valves in middle-aged patients.
  
  
  METHODS
  Patients (N = 659) aged between 50 and 65 years who had first-time aortic valve replacement (AVR) and/or mitral valve replacement (MVR) with contemporary prostheses were followed prospectively after surgery. The total follow-up was 3,402 patient-years (mean 5.1 +/- 4.1 years; maximum 18.3 years). Outcomes were examined with multivariate actuarial methods. A composite outcome of major adverse prosthesis-related events (MAPE) was defined as the occurrence of reoperation, endocarditis, major bleeding, or thromboembolism.
  
  
  RESULTS
  Ten-year survival was 73.2 +/- 4.2% after mechanical AVR, 75.1 +/- 12.6% after bioprosthetic AVR, 74.1 +/- 4.6% after mechanical MVR, and 77.9 +/- 7.4% after bioprosthetic MVR (P=NS). Ten-year reoperation rates were 35.4% and 21.3% with aortic and mitral bioprostheses, respectively. Major bleeding occurred more often following mechanical MVR (hazard ratio [HR]: 3.3; 95% confidence interval [CI] 1.2, 9.0; P = 0.022), and the incidence of any thromboembolic event was more common after mechanical MVR (HR: 4.7; CI 1.4, 13.3; P = 0.01). Overall freedom from MAPE at 10 years was 70.2 +/- 4.1% for mechanical AVR patients, 41.0+/-30.3% for bioprosthetic AVR patients, 53.3 +/- 8.8% for mechanical MVR patients, and 61.2 +/- 9.2% for bioprosthetic MVR patients. Although a trend existed towards more MAPE amongst middle-age patients with tissue valves, multivariate analysis did not identify the presence of a bioprosthesis as an independent risk factor for MAPE (HR: 1.3; CI 0.9, 2.0; P = 0.22).
  
  
  CONCLUSIONS
  In middle-aged patients, MAPE may occur more often in patients with bioprosthetic valves, but definitive conclusions necessitate the accumulation of additional follow-up. At present, these data do not support lowering the usual cutoff for implantation of a tissue valve below the age of 65.
authors.affiliation: Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Suite 3403, Ottawa, Ont. K1Y 4W7, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kulik
authors.forename: Pierre
authors.initials: P
authors.lastname: Bédard
authors.forename: B-Khanh
authors.initials: BK
authors.lastname: Lam
authors.forename: Fraser D
authors.initials: FD
authors.lastname: Rubens
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hendry
authors.forename: Roy G
authors.initials: RG
authors.lastname: Masters
authors.forename: Thierry G
authors.initials: TG
authors.lastname: Mesana
authors.forename: Marc
authors.initials: M
authors.lastname: Ruel
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery; D001705:Bioprosthesis; D004696:Endocarditis / Q000209:etiology; D005260:Female; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D012086:Reoperation; D020521:Stroke / Q000209:etiology; D013923:Thromboembolism / Q000209:etiology; D016896:Treatment Outcome