Comparison of bioprosthesis and mechanical valves, a meta-analysis of randomised clinical trials.

The main purpose of this meta-analysis was to compare the outcomes of patients who randomly received mechanical valves or bioprosthesis, over a long-term clinical follow-up. We found only three trials meeting our selection criteria with a total of 1229 patients (8069. 5 patient-yr). Bleeding was more frequent in patients with mechanical prostheses both after 5 yr (RR=2.6; IC=[1.9;3.5]; P<0.0001) and 11 yr (RR=1.6; IC=[1.2;2.2]; P<0.001) of follow-up. However, the increased risk of bleeding at 11 yr was only statistically significant with mechanical prostheses in the aortic position (RR=1.93; IC=[1.36;2. 74]; P=0.0002). Reoperation was significantly more frequent in patients with bioprosthesis after 11 yr follow-up (RR=0.4; IC=[0.3;0. 6]; P<0.001). Endocarditis was more frequent after 11 yr (RR=0.6; IC=[0.3;0.95]; P<0.05) in patients with mechanical prostheses but these results were heterogeneous between mitral and aortic valves. The choice of valve type does not significantly influence survival.