Mechanical or bioprosthetic valves in the elderly: a 20-year comparison.

BACKGROUND: Our objective was to compare long-term results of mechanical and bioprosthetic valve replacement in patients older than 70 years. METHODS: Patients older than 70 years who had either a St. Jude Medical (SJM) mechanical prosthesis or any bioprosthesis (BP) implanted between January 1977 and December 1997 were identified. Alive patients were interviewed by telephone during a closing interval of 130 days. RESULTS: Complete follow-up was achieved with a total follow-up of 2,264 patient years. A total of 547 patients had 448 aortic valve replacements (199 SJM and 249 BP) and 99 had mitral valve replacements (76 SJM and 23 BP). A further 30 patients had double valve replacement. One hundred ninety of the 577 patients (33%) had coronary artery bypass grafting in addition to the valve replacement. Survival analysis showed no advantage for either mechanical or bioprosthetic valves. There was also no difference in thromboembolic rates, paravalvular leaks, structural dysfunction, and endocarditis rates. However, patients with mechanical valves had a significantly greater risk of major (p < 0.0001) and minor bleeding (p = 0.002) events. CONCLUSIONS: Bioprosthetic valves do not offer a survival advantage over mechanical valves among the elderly. However, anticoagulant-related mortality and morbidity is statistically higher for patients with mechanical valves.