In vitro assessment of mitral valve prostheses.

The performance of five prosthetic mitral valves (Ionescu-Shiley, Hancock, Carpentier-Edwards, Starr-Edwards, and Björk-Shiley), all of the same nominal size (29 mm), has been assessed in a hydromechanical simulation of the left heart at three pulse rates. The mean and maximum transvalvular pressure differences, the observed and/or calculated area, and the energy loss for each valve were compared. It was found that each measure of performance rates the valves in the same order or merit, with the Ionescu-Shiley valve performing the best and the Hancock the worst among the valves tested.