Hemodynamic performance on exercise: comparison of a stentless and stented biological aortic valve replacement.
OBJECTIVE
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.


CONCLUSIONS
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.
Cardiothoracic Centre, Valve Study Group, St. Thomas' Hospital, London, UK. johnchambers@dial.pipex.com
John
J
Chambers
Helen
H
Rimington
Ronak
R
Rajani
Fiona
F
Hodson
Christopher
C
Blauth
D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve; D001705:Bioprosthesis; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012146:Rest