Prognostic implications of guideline-directed medical therapy in functional mitral regurgitation: a meta-analysis

Abstract Background Randomized evidence of the role of heart failure medical therapy for patients with functional mitral regurgitation (FMR) is lacking. Purpose The present meta-analysis sought to investigate the independent long-term prognostic impact of the different medical categories recommended in heart failure, for subjects with FMR. Methods A systematic literature review was conducted in electronic databases to identify studies reporting the association of renin angiotensin system inhibitors (RASi), beta-blockers (BBs), and mineralocorticoid receptor antagonists (MRAs) with outcomes in FMR. A random-effects meta-analysis was conducted to quantify the unadjusted and adjusted hazard ratios [(a)HRs] for all-cause death and the composite outcome in each medical category. Results The final sample comprised 12 studies with 6,715 FMR patients (Picture 1). The use of RASi and BBs was associated with a significantly lower risk for all-cause mortality (HR 0.52 [0.39-0.68]; p <0.00001, I2 =62 % and HR 0.62 [0.49-0.77]; p <0.0001, I2 =44 % respectively) and for the composite outcome (HR 0.54 [0.44-0.67]; p <0.00001, I2 =33 % and HR 0.62 [0.52-0.75], p <0.00001, I2 =35% respectively) in unadjusted models (Picture 2). Both RASi (aHR 0.73 [0.56-0.95], p =0.02, I2 =52%) and BBs (aHR 0.60 [0.41-0.88], p = 0.009, I2 =55%) retained their association with the composite outcome in pooled adjusted models (Picture 2). The prognostic benefit of using RASi or BBs was retained in subgroup analysis including only patients with moderate of severe FMR. MRAs did not demonstrate a significant association with improved outcomes in FMR. Conclusions RASi and BBs appear to have a favorable prognostic impact in patients with FMR, regardless of regurgitation severity.Study flow chart for study selectionPharmacotherapy and prognosis in FMR