Background: Stentless aortic bioprostheses were shown to be hemodynamically superior to earlier generations of stented bioprostheses. Modern stented valve designs have improved hemodynamics. A prospective randomized controlled trial was undertaken to compare stentless versus modern stented valves. Our aim was to determine any differences in early postoperative clinical and hemodynamic outcomes.
Methods: Patients with severe aortic valve stenosis (n = 161) undergoing aortic valve replacement were randomized intraoperatively to receive either the C-E Perimount (Edwards Lifesciences, Irvine, CA) pericardial stented bioprosthesis (n = 81) or the Prima Plus (Edwards Lifesciences) (porcine stentless bioprosthesis (n = 80). Transthoracic echocardiograms were performed at one week and eight weeks postoperatively to assess left ventricular mass (LVM) and transvalvular gradients (TVG).
Results: There were no differences between the two groups in baseline characteristics. Cardiopulmonary bypass and ischemic times were longer in the stentless group. Despite similar native aortic annular diameters, the mean size of the prosthesis used in the stentless group was 2.1 mm (SD = 2.8) larger (p < 0.001). Early (30-day) mortality (stentless 3.7% vs stented 2.5%; p = 0.68) and morbidity was similar between groups. Eight weeks postoperatively, LVM (stentless 199 +/- 70 vs stented 204 +/- 66 grams; p = 0.32) and TVG decreased in both groups (mean systolic gradient; stentless 10 +/- 3 vs stented 10 +/- 4 mm Hg; p = 0.54) but there was no significant difference between groups.
Conclusions: Despite longer ischemic times in the stentless group, early postoperative outcomes were similar. Both stented and stentless aortic valve replacement offers excellent hemodynamics and can be achieved with low perioperative mortality.