Are stentless valves hemodynamically superior to stented valves? A prospective randomized trial.
BACKGROUND
Although stentless aortic bioprostheses are believed to offer improved outcomes, hemodynamic benefits remain unsubstantiated.


METHODS
Fifty-three patients were randomized to receive the stented C-E pericardial valve (CE) and 46 patients the Toronto Stentless Porcine valve (SPV). Annuli were sized for the optimal insertion of both valve types, such that surgeons were required to commit to specific valve sizes before randomization. Echocardiographic measurements and functional status (Duke Activity Status Index) were assessed at 3 and 12 months postoperatively.


RESULTS
Although cardiopulmonary bypass times (CE: 118.6+/-36.3 minutes; SPV: 148.5+/-30.9 minutes; p = 0.0001) and aortic cross-clamp times (CE: 95.4+/-28.6 minutes; SPV: 123.6+/-24.1 minutes; p = 0.0001) were significantly prolonged in the SPV group, perioperative morbidity and mortality was similar between groups. Neither valve offered a superior internal diameter for any given annular diameter (mean decrease in left ventricular outflow tract diameter after valvular implantation: SPV: 3.4+/-1.11 mm versus CE: 3.7+/-1.33 mm; p = 0.25). Although labeled mean valve size was significantly larger in the SPV group, the actual mean valve size based on internal valvular diameter was no different between groups (CE: 21.9+/-2.0 mm; SPV: 22.3+/-2.0 mm; p = 0.286). Although effective orifice areas increased, and mean and peak transvalvular gradients decreased in both groups over time, no differences were demonstrated between groups at 12 months. Similarly, although significant regression of left ventricular mass was accomplished in both groups over time, no differences were demonstrated between groups. Finally, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups at 12 months postoperatively.


CONCLUSIONS
Although offering excellent outcomes, stentless valves did not demonstrate superior hemodynamic indices in comparison to stented valves up to 12 months after implantation.
Cohen
Gideon
G
Division of Cardiovascular Surgery, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, Canada.
Christakis
George T
GT
Joyner
Campbell D
CD
Morgan
Christopher D
CD
Tamariz
Miguel
M
Hanayama
Naoji
N
Mallidi
Hari
H
Szalai
J P
JP
Katic
Marko
M
Rao
Vivek
V
Fremes
Stephen E
SE
Goldman
Bernard S
BS
D000368:Aged; D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000503:physiopathology / Q000601:surgery; D001705:Bioprosthesis; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D016277:Ventricular Function, Left