Figure 2.

The Veterans Affairs randomised trial comparing outcome following valve replacement with a mechanical (Bjork-Shiley) versus a porcine bioprosthetic valve. Cumulative mortality curves show significantly higher mortality over 15 years of follow up with bioprostheses for those undergoing aortic valve replacement (AVR). For mitral valve replacement (MVR) cumulative mortality was initially higher with mechanical prostheses but with more prolonged follow up the mortality curves converged. Reproduced from Hammermeister K, et al. J Am Coll Cardiol 2000:36;1152–8, with permission of the publisher.