Randomized comparison of stentless versus stented valves for aortic stenosis - Effects on left ventricular mass

Background-Aortic valve replacement (AVR) is the established treatment for severe aortic stenosis. In response to the long-term results of aortic homografts, stentless porcine valves were introduced as an alternative low-resistance valve. We conducted a randomized trial comparing a stentless with a stented porcine valve in adults with severe aortic stenosis. Methods and Results-The primary outcome was change in left ventricular mass index (LVMI) measured by transthoracic echocardiography and, in a subset, by cardiovascular MR. Measurements were taken before valve replacement and at 6 and 12 months. Patients undergoing AVR with an aortic annulus <= 25 mm in diameter were randomly allocated to a stentless ( n = 93) or a stented supra-annular ( n = 97) valve. There were no significant differences in mean LVMI between the stentless versus stented groups at baseline ( 176 +/- 62 and 182 +/- 63 g/m(2), respectively) or at 6 months ( 142 +/- 49 and 131 +/- 45 g/m(2), respectively), although within-group changes from baseline to 6 months were highly significant. Changes in LVMI measured by cardiovascular MR ( n = 38) were consistent with the echo findings. There was a greater reduction in peak aortic velocity ( P < 0.001) and a greater increase in indexed effective orifice area ( P < 0.001) in the stentless group than in the stented group. There were no differences in clinical outcomes between the 2 valve groups. Conclusions-Despite significant differences in indexed effective orifice area and peak flow velocity in favor of the stentless valve, there were similar reductions in left ventricular mass at 6 months with both stented and stentless valves, which persisted at 12 months.