Early mitral valve surgery for chronic severe mitral regurgitation optimizes left ventricular performance and left ventricular mass regression

Objective: The optimal timing of mitral valve surgery for severe mitral regurgitation is controversial. We aimed to evaluate the changes in left ventricular performance using ventricular energetics and left ventricular mass regression after the surgery to determine the appropriate surgical timing in asymptomatic patients with severe mitral regurgitation. Methods: Fifty consecutive asymptomatic or minimally symptomatic patients who electively underwent the surgery for severe mitral regurgitation were studied retrospectively. Contractility (end-systolic elastance), afterload (effective arterial elastance), and efficiency (ventriculoarterial coupling and ratio of stroke work to pressure-volume area), and left ventricular mass index were measured echocardiographically before and 1 month after surgery. Two-way repeated-measures analysis of variance was used to compare the parameters between patients with (n = 17) and without (n = 33) left ventricular dysfunction (ie, ejection fraction ≤60% and/or end-systolic dimension ≥40 mm). Results: Contractility did not change significantly (P =.94) but the afterload increased significantly (P <.0001) in both groups. Consequently, the efficiency deteriorated significantly (ventriculoarterial coupling, P =.0004; ratio of stroke work to pressure-volume area, P <.0001). Furthermore, the left ventricular mass index improved remarkably in both groups (P <.0001). Alternatively, the patients with normal left ventricular function had greater contractility (P <.0001), less worsened efficiency (P <.0001 and P <.0001, respectively), and a better left ventricular mass index (P =.0002) after surgery. Conclusions: Early surgery for severe mitral regurgitation preserves left ventricular performance and improves left ventricular mass regression in asymptomatic patients with normal ventricular function.