Predictors of functional mitral regurgitation improvement during a short-term follow-up after CRT implantation.

Abstract The study was undertaken to assess the predictive role of myocardial contractile reserve for the functional mitral regurgitation (FMR) improvement after cardiac resynchronization therapy (CRT) implantation and to define other predictors of FMR improvement (FMRI) and the impact of FMRI on the left ventricular (LV) reverse remodeling. Among 90 patients in whom echocardiography was performed 1-day before and 6 weeks after CRT implantation, 66 with at least FMR(2+) in a four-point scale [mean age 64±10, mean LV ejection fraction (LVEF) 25,7%±6, ischemic etiology 48%] were included. FMRI was defined as the reduction of the FMR severity by at least one grade. The patients were divided into groups: A with FMRI (n=30) and B without FMRI (n=36). Contractile reserve was evaluated using low-dose dobutamine stress-echo before CRT implantation and was defined as a relative improvement in LVEF more than 20% and segmental contractility improvement. Reverse remodeling was defined as the reduction of the LV end-systolic volume (LVESV) by at least 15%. Cox regression multivariate analysis revealed the following predictors for FMRI: contractile reserve preserved in more than three segments with an OR =5.7, (95% CI 1.81-17.97), p =0.005, sensitivity 65.5%, specificity 72.2%; (AUC =0.727) and LV end-diastolic diameter≤74mm with an OR=2.09, (95% CI 0.75-5.78), p