Risk of stroke, reoperation, major bleeding, and cardiovascular death. Cumulative incidence of stroke, aortic valve reoperation, major bleeding, and cardiovascular death in propensity score-matched patients aged 50–69 years who had undergone aortic valve replacements with mechanical valves vs. bioprostheses. Note: The curves for biological and mechanical valves are superimposed in the graph showing cumulative incidence for cardiovascular death.