Effect of mitral valve replacement on left ventricular function in subjects with severe rheumatic mitral regurgitation.

Abstract

This study describes the effects of mitral valve replacement (MVR) on left ventricular (LV) function in patients with severe rheumatic mitral regurgitation (MR). This was a retrospective analysis over a nine-year period (2005-2013). Clinical and echocardiographic parameters were recorded pre-operatively and at two weeks, six weeks to three months and six months following MVR. Of the 132 patients included in the study, 66% were in New York Heart Association (NYHA) class III-IV and 38% presented with clinical features of heart failure. Pre-operatively, 28% of subjects had impaired LV function [ejection fraction (EF) < 60%] and the majority had advanced chamber dilatation [left ventricular end-diastolic diameter (LVEDD) 60.7 ± 7.9 mm (n = 132), left ventricular end-systolic diameter (LVESD) 39.9 ± 7.2 mm (n = 118) and left atrial size 61.2 ± 12.6 mm (n = 128)]. Paired analysis of 83 patients revealed that the EF was > 55% in 87% (n = 72) pre-operatively, decreasing to 20% (n = 17) of patients at two weeks postoperatively (p < 0.001); thereafter an EF > 55% was recorded in 60% (n = 50) at the six-month follow-up visit (p < 0.001). On multivariate analysis, only LVESD emerged as a significant predictor of postoperative LV dysfunction. In this study, most patients with severe MR presented late with significant impairment of LV function and chamber dilatation that often did not recover fully after surgery. This study emphasises early comprehensive evaluation of severe MR followed by timeous surgery in order to preserve LV function.