Background and aim of the study: Although stentless valves are expected to be hemodynamically superior to stented valves, the results of comparative trials have been inconsistent. The study aim was to compare hemodynamic function at rest and on exercise in 50 stentless and stented biological replacement aortic valves
Methods: Twenty-one patients with a Toronto‘ stentless porcine valve and 29 with a Perimount‘ stented bovine pericardial valve were exercised using a bicycle ergometer. Echocardiography was performed before, and during exercise testing.
Results: Patients with either valve type were exercised to a

similar degree. Transaortic resistance was slightly lower in the Perimount compared with the Toronto at rest (p = 0.03) and at peak exercise (p = 0.04), and flow was higher in the Perimount at rest (p = 0.007), but not at peak exercise. There were no significant differences between the valve types in peak velocity, mean pressure difference or effective orifice area either at rest or on peak exercise.
Conclusion: There were no clinically significant differences in hemodynamic function between the stented and stentless biological valves chosen for comparison either at rest or during bicycle exercise.
The Journal of Heart Valve Disease 2004;13:729-733