Left ventricular reverse remodelling predicts long-term outcomes in patients with functional mitral regurgitation undergoing MitraClip therapy: results from a multicentre registry

Aims: To explore whether left ventricular reverse remodelling (LVRR) is a predictor of outcomes in patients with functional mitral regurgitation (FMR) undergoing MitraClip procedure. Methods and results: We analysed 184 consecutive patients with FMR who underwent successful MitraClip procedure. LVRR was defined as a reduction in left ventricular end-systolic volume ≥ 10% from baseline to 6 months. LVRR was observed in 79 (42.9%) patients. Compared with non-LVRR, LVRR patients were more likely to be females, less likely to have an ischaemic aetiology of mitral regurgitation or a prior (<6 months) heart failure (HF) hospitalization, and had smaller left ventricular dimensions. New York Heart Association class improved from baseline up to 1-year follow-up in both groups. Higher rates of overall survival (87.3% vs. 75.2%, P = 0.039), freedom from HF hospitalization (77.2% vs. 60%, P = 0.020), and freedom from the composite endpoint (cardiovascular mortality or HF hospitalization) (74.7% vs. 55.2%; P = 0.012) were observed in LVRR vs. non-LVRR patients at 2-year follow-up. LVRR was associated with a significant reduction of the adjusted relative risk of mortality, HF hospitalization and composite endpoint [hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.20–0.96, P = 0.040; HR 0.55; 95% CI 0.32–0.97, P = 0.038; and HR 0.54; 95% CI 0.32–0.92, P = 0.023, respectively]. Female gender, absence of diabetes, freedom from prior HF hospitalization, non-ischaemic aetiology of mitral regurgitation, and left ventricular end-diastolic diameter < 75 mm were found to be independent predictors of LVRR. Conclusions: Left ventricular reverse remodelling is associated with better long-term outcomes in patients with FMR successfully treated with MitraClip. A careful patient selection may be useful as specific baseline features predict favourable left ventricular remodelling. [Correction added on 17 January 2019, after online publication: the preceding sentence has been changed.].