Changes in left ventricular mass and function after aortic valve replacement: A comparison between stentless and stented bioprosthetic valves

The objective of this study was to compare stentless bioprostheses with ste nted bioprostheses with regard to the postoperative changes in left ventric ular (LV) mass and function. Forty patients with aortic stenosis undergoing valve replacement with a stentless (20 patients) or a stented (20 patients ) bioprosthesis were evaluated early (baseline), 1 year, and 2 years after operation. Left ventricular mass index was calculated with the corrected Am erican Society of Echocardiography formula. The relative changes between en d-diastole and end-systole in LV mid-wall radius, length, and volume (eject ion fraction) were determined with a previously validated model for dynamic geometry of the left ventricle. Overall, a significant decrease was found in LV mass index (from 155 +/- 30 to 112 +/- 23 g/m(2); P < .001) and a sig nificant increase in longitudinal shortening (from 0.12 +/- 0.11 to 0.22 +/ - 0.08; P < .001), and ejection fractions (from 0.67 +/- 0.11 to 0.71 +/- 0 .10; P = .017). No significant change was found in the mid-wall radius shor tening fraction. Two years after surgery, the extent of LV mass regression was greater in stentless bioprostheses (-51 +/- 18 vs -35 +/- 17 g/m(2); P = .01), though the average mass index was similar in both groups (114 +/- 2 6 vs 110 +/- 20 g/m(2)). Also at 2 years, the longitudinal shortening fract ion was greater in patients with a stentless bioprosthesis (0.25 +/- 0.07 v s 0.18 +/- 0.08; P =.03). In conclusion, this study suggests that the super ior hemodynamic performance of stentless bioprostheses may have some benefi ts with regard to LV mass regression and function after aortic valve replac ement. The significance of these benefits in terms of prognosis remains to be determined.