Prognostic Value of Pre-operative Atrial Fibrillation in Patients with Secondary Mitral Regurgitation Undergoing MitraClip Implantation

Limited data are available regarding the independent prognostic role of pre-operative AF after transcatheter mitral valve repair with MitraClip. We sought to evaluate the impact of pre-operative atrial fibrillation (AF) in patients with heart failure (HF) and concomitant secondary mitral regurgitation (MR) after MitraClip treatment. The study included 605 patients with significant secondary MR from a multicenter international registry. Patients were stratified into two groups according to the presence or absence of pre-operative AF. Primary endpoint was 5-year overall death, secondary endpoints were 5-year cardiac death and first re-hospitalization for HF. To account for baseline differences, patients were propensity score matched 1:1. The overall prevalence of pre-operative AF was 44%. At 5-year Kaplan-Meier analysis, compared to patients without AF, those with AF had significantly more adverse events in term of overall death (67% vs. 43%; HR 1.84, log-rank p<0.001) and cardiac death (56% vs. 29%; HR 2.11, log-rank p<0.001) and re-hospitalization for HF (63% vs. 52%; HR 1.33, log-rank p = 0.048). Multivariate analysis identified AF as independent predictor of worse outcome in term of primary endpoint (HR 1.729, 95% C.I. 1.060 - 2.821; p = 0.028). After propensity score matching, patients with AF had higher rates of death and cardiac mortality but similar rates of re-hospitalization for HF. In conclusion, in patients with HF undergoing MitraClip treatment for secondary MR, pre-operative AF is common and an unfavourable predictor of 5-year death and cardiac death. However, AF did not affect the frequency of re-hospitalization for HF.