부산대학교 도서관

OBJECTIVE:: To compare survival and outcome in patients receiving a mechanical or bioprosthetic heart valve prosthesis. DESIGN:: Randomised prospective trial. SETTING:: Tertiary cardiac centre.Patients: Between 1975 and 1979, patients were randomised to receive either a Bjork-Shiley or a porcine prostheses. The mitral valve was replaced in 261 patients, the aortic in 211, and both valves in 61 patients. Follow up now averages 20 years. MAIN OUTCOME MEASURES:: Death, reoperation, bleeding, embolism, and endocarditis. RESULTS:: After 20 years there was no difference in survival (Bjork-Shiley v porcine prosthesis (mean (SEM)): 25.0 (2.7)%v 22.6 (2.7)%, log rank test p = 0.39). Reoperation for valve failure was undertaken in 91 patients with porcine prostheses and in 22 with Bjork-Shiley prostheses. An analysis combining death and reoperation as end points confirmed that Bjork-Shiley patients had improved survival with the original prosthesis intact (23.5 (2.6)%v 6.7 (1.6)%, log rank test p < 0.0001); this difference became apparent after 8–10 years in patients undergoing mitral valve replacement, and after 12–14 years in those undergoing aortic valve replacement. Major bleeding was more common in Bjork-Shiley patients (40.7 (5.4)%v 27.9 (8.4)% after 20 years, p = 0.008), but there was no significant difference in major embolism or endocarditis. CONCLUSIONS:: Survival with an intact valve is better among patients with the Bjork-Shiley spherical tilting disc prosthesis than with a porcine prosthesis but there is an attendant increased risk of bleeding.