Abstract
Background: Prostheses used for aortic valve replacement may be small in relation to body size, causing prosthesispatient
mismatch and delaying left ventricular mass regression. This study examined the effect of prosthesis-patient
mismatch on regression of left ventricular mass after aortic valve replacement.
Methods:We prospectively studied 96 patients undergoing aortic valve replacement between 2007 and 2012. Mean and
peak gradients and indexed effective orifice area were measured by transthoracic echocardiography at 3 and 6 months
postoperatively. Patient-prosthesis mismatch was defined as indexed effective orifice area 40.85 cm2m2.
Results: Moderate prosthesis-patient mismatch was present in 25% of patients. There were no significant differences in
demographic and operative data between patients with and without prosthesis-patient mismatch. Left ventricular dimensions,
posterior wall thickness, transvalvular gradients, and left ventricular mass decreased significantly after aortic valve
replacement in both groups. The interventricular septal diameter and left ventricular mass index regression, and left
ventricular ejection fraction were better in patients without prosthesis-patient mismatch. There was a significant positive
correlation between the postoperative indexed effective orifice area of each valve prosthesis and the rate of left ventricular
mass regression.
Conclusions: Prosthesis-patient mismatch leads to higher transprosthetic gradients and impaired left ventricular mass
regression. A small-sized valve prosthesis does not necessarily result in prosthesis-patient mismatch, and may be perfectly
adequate in patient with small body size.