Impact of cardiac resynchronization therapy on mitral valve apparatus geometry and clinical outcomes in patients with secondary mitral regurgitation

Background Cardiac resynchronization therapy (CRT) may improve secondary mitral regurgitation (MR) in patients with cardiomyopathy. The effects on mitral valve (MV) and left ventricular (LV) geometry, however, have not been clearly defined. Methods Between 2009 and 2012, 229 CRT implants were performed at a single academic center. Seventy‐one had ≥mild MR at baseline and serial echocardiography, without subsequent MV intervention. The pre‐CRT and follow‐up echocardiograms were retrospectively reviewed for (1) MV and LV geometry measurements; (2) MR grade; and (3) LV remodeling indices. Results The mean age was 67 ± 15 years, and the cardiomyopathy was ischemic in 37 (52%). At a mean follow‐up of 4.0 ± 1.9 years, there were significant improvements in LV ejection fraction and size, MR grade, MV tenting area and anterior leaflet tethering angle, and end‐systolic interpapillary muscle distance (IPMD), and reductions in moderate‐to‐severe or severe MR (27% vs 15%; P = .04) and New York Heart Association functional class III/IV symptoms (83% vs 41%; P