Abstract 15631: Predictors of Functional Mitral Regurgitation Progression vs Regression in Patients With Non-Ischemic Cardiomyopathy: A Multi-Modality Study

Background: Functional mitral regurgitation (FMR) is associated with poor prognosis, however the determinants of FMR progression are not well understood. We aimed to determine clinical and cardiac magnetic resonance imaging (CMR) factors associated with FMR progression in patients with non-ischemic cardiomyopathy (NICM) who underwent baseline and follow-up echocardiography. Methods: NICM patients undergoing CMR between 12/2002-12/2017 with baseline (within 90 days of CMR) and follow-up echocardiography were evaluated. Progressive FMR was assessed by echocardiography based on reported FMR severity (none, mild, moderate, moderate-severe, severe). Associations between clinical and CMR parameters (left ventricular and left atrial (LA) size and function, late gadolinium enhancement, and mitral valve (MV) geometry quantification) and progressive FMR were assessed by univariable and stepwise multivariable linear regression. Results: Amongst 311 NICM patients (age 53±15.7 years, female 121 (38.9%)). A total of 17 patients (5.5%) had at least 1-grade of deterioration in FMR, while 66 patients (21.2%) had at least 1-grade of improvement. Univariable and multivariable analyses results are listed in the table. Mean baseline mitral regurgitant fraction by CMR was 14% ± 13%, while the mean of mitral regurgitation severity by echo was in the mild range (1.28 ±1). Baseline FMR grade by TTE (P<0.001), CMR-LA volume indexed (P=0.003), sphericity ratio (P=0.005), MV annular mean indexed (P=0.027), and BMI (P=0.044) were independently associated with significant change in FMR. Conclusion: CMR-derived remodeling, LA and MV geometry parameters predicted progressive vs regression in FMR. Further studies are needed to determine if CMR predictors of FMR progression vs regression can improve selection criteria for procedural intervention vs guideline-directed medical therapy.