Aortic valve replacement: a prospective randomized evaluation of mechanical versus biological valves in patients ages 55 to 70 years

OBJECTIVES: The aim of this study was to determine long-term results between bioprosthetic (BP) and mechanical (MP) aortic valves in middle-aged patients. BACKGROUND: It has not been established which is the best aortic valve substitute in patients ages 55 to 70 years. We conducted a randomized study to compare long-term outcomes between BP and MP aortic valves. METHODS: Between January 1995 and June 2003, 310 patients were randomized to receive a BP or an MP aortic valve. Primary end points of the study were survival, valve failure, and reoperation. RESULTS: One hundred fifty-five patients received a BP valve, and 155 patients received an MP valve. Four patients died, perioperatively, in the MP group (2.6%), and 6 patients died in the BP group (3.9%, p = 0.4). At late follow-up (mean 106 +/- 28 months) 41 patients died in the MP group and 45 patients died in the BP group (p = 0.6). There was no difference in the survival rate at 13 years between the MP and BP groups. Valve failures and reoperations were more frequent in the BP group compared with the MP group (p = 0.0001 and p = 0.0003, respectively). There were no differences in the linearized rate of thromboembolism, bleeding, endocarditis, and major adverse prosthesis-related events (MAPE) between the MP and BP valve groups. CONCLUSIONS: At 13 years, patients undergoing aortic valve replacement either with MP or BP valves had a similar survival rate as well the same rate of occurrence of thromboembolism, bleeding, endocarditis, and MAPE, but patients who had undergone aortic valve replacement with BP valves faced a significantly higher risk of valve failure and reoperation.