LEFT-VENTRICULAR MASS REGRESSION EARLY AFTER AORTIC-VALVE REPLACEMENT

Background. Regression of left ventricular hypertrophy is an important and well-recognized salutary effect of aortic valve replacement. The earliest evidence of left ventricular mass regression after aortic val ve replacement and the influence of prosthesis type are not well known , and were the focus of this study. Methods. Transthoracic echocardiog raphy was used to measure left ventricular mass index preoperatively a nd before discharge in 57 consecutive patients undergoing isolated aor tic valve replacement (with or without coronary artery bypass grafting ). Results. Three patients were excluded from the study because of ina bility to obtain accurate M-mode echocardiographic images for left ven tricular mass measurement preoperatively (1) or postoperatively (2). O f the remaining 54 patients, mechanical bileaflet valves were used in 19, stented tissue bioprostheses were implanted in 15, and a stentless porcine bioprosthesis was chosen for 20. Postoperative echocardiogram s were obtained 4.9 +/- 2.3 days after aortic valve replacement (range , 2 to 9 days). A two-way repeated-measures analysis of variance demon strated a significant reduction of left ventricular mass index before discharge (preoperative 141.4 +/- 45.2 g/m(2), postoperative 127.5 +/- 32.8 g/m(2); p = 0.0005) but no differences between prostheses. Concl usions. Left ventricular mass regression begins early after aortic val ve replacement, probably because of reduction of transvalvular gradien ts and left ventricular wall stress. At least in the very early postop erative period, the type of prosthesis does not influence-the extent o f mass regression.