Impact of Atrial Fibrillation Catheter Ablation on Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) is a common complication of atrial fibrillation (AF), contributing to adverse cardiac remodeling and poor outcomes. While catheter ablation effectively restores sinus rhythm, its impact on FMR improvement and clinical outcomes remains unclear. This retrospective study included 268 patients undergoing first-time AF ablation, excluding primary valve disease or prior mitral valve intervention. Of 140 patients with baseline FMR, 81 (57.9%) showed MR improvement (≥1-grade reduction at 1 year), while 59 (42.1%) had no improvement at 1-year follow-up. Intermediate-term outcomes (mean follow-up 28.0 ± 10.6 months) were assessed in 109 FMR patients for heart failure hospitalization, stroke/TIA, and mortality. FMR patients were older, with more persistent AF, comorbidities, and worse cardiac/renal function than non-FMR patients. MR improvement was independently predicted by baseline moderate/severe MR and smaller left ventricular systolic dimensions, but less likely with coronary artery disease or longer AF duration. MR improvement correlated with favorable cardiac remodeling, including reduced ventricular dimensions and improved ejection fraction. AF recurrence was higher in FMR versus non-FMR but similar between improved/non-improved MR groups. MR improvement was associated with fewer composite adverse events and no stroke/TIA. Cox regression analysis identified nonimproved MR as independent predictors of adverse clinical outcomes, while Kaplan-Meier analysis demonstrated better event-free survival for both composite endpoints and stroke/TIA in the improved MR group. In conclusion, AF catheter ablation is associated with FMR improvement in over half of patients, with favorable cardiac remodeling and better clinical outcomes. These findings highlight its clinical significance as a prognostic marker and support early ablation in AF patients with FMR to improve clinical outcomes.