Impact of the improvement of valve area achieved with aortic valve replacement on the regression of left ventricular hypertrophy in patients with pure aortic stenosis.

Background: Previous studies have reported that patient-prosthesis mismatch may be associated with lesser regression of left ventricular hypertrophy. However, among the patients with mismatch, the extent of left ventricular mass regression varied markedly from one patient to another, and we hypothesized that it could be related to the magnitude of the increase in valve area achieved with aortic valve replacement. Our aim was to examine the relationship between the improvement in valve effective orifice area obtained with aortic valve replacement and the extent of postoperative left ventricular mass regression in patients with patient-prosthesis mismatch.

Methods: Preoperative and postoperative measurements of valve effective orifice area, transvalvular pressure gradient, and left ventricular mass were obtained by Doppler echocardiography in 111 patients with pure aortic stenosis who were found to have patient-prosthesis mismatch based on an indexed effective orifice area of 0.8 cm2/m2 or less after operation.

Results: On average, the valve effective orifice area increased by 0.45 +/- 0.24 cm2/m2 with operation, and mean transvalvular pressure gradients decreased by -31.6 +/- 13.5 mm Hg. The absolute and relative differences between preoperative and postoperative left ventricular mass were -28 +/- 30 g and -17% +/- 18%, respectively. In multivariate analysis, higher preoperative left ventricular mass (p < 0.0001) and larger increase in indexed valve effective orifice area with operation (p = 0.019) were independently associated with greater left ventricular mass regression.

Conclusions: This study shows that in patients with patient-prosthesis mismatch, the degree of left ventricular mass regression is influenced by the increase in valve effective orifice area achieved by aortic valve replacement.