Predictors and prognostic impact of progressive ischemic mitral regurgitation in patients with advanced ischemic cardiomyopathy: A multimodality study

Abstract

Background - Ischemic mitral regurgitation (IMR) is associated with poor outcomes. It is unknown what factors contribute to progression of IMR and how progressive IMR affects outcomes. We sought to determine imaging predictors of IMR progression and to determine if progressive IMR is an independent predictor of survival in patients with advanced ischemic cardiomyopathy. Methods and Results - Consecutive advanced ischemic cardiomyopathy patients who underwent cardiac magnetic resonance and echocardiograms at baseline with echocardiographic follow-up were studied. Cardiac magnetic resonance was used to assess left ventricular volumes, infarct size, and mitral valve geometry. The effective regurgitant orifice area (EROA) was calculated from the proximal isovelocity surface area by echocardiography. Repeated measures mixed effects and Cox proportional hazards regression models were built to identify predictors of IMR progression and survival. We evaluated 336 patients (age, 62±11 years) over a median follow-up time of 54 months: 154 patients were subsequently revascularized, and 182 patients were medically treated. Ninety-eight patients (29%) demonstrated an increase in EROA values of ≥0.1 cm2. There were 87 adverse events (death or transplant). On multivariable analysis, infarct size (P<0.001), progression in IMR (P=0.008), age (P=0.003), and baseline EROA (P=0.010) were independently associated with adverse events. Independent predictors of IMR progression were as follows: baseline EROA (P<0.001), left ventricular end-systolic volume index (P=0.014), and total scar (P=0.036). Conclusions - IMR frequently increases in severity, and progression is independently associated with adverse left ventricular remodeling and infarct size, as assessed by cardiac magnetic resonance. Furthermore, IMR progression is a powerful independent predictor of adverse events, even after controlling for the severity of IMR at baseline.