Abstract Body (Do not enter title and authors here): Background: Recent studies showed that functional mitral valve regurgitation (FMR) was associated with higher long-term mortality in chronic heart failure patients and poorer outcomes in those with atrial fibrillation (AF), including a higher risk of atrial cardiomyopathy. However, the effect of baseline FMR on outcomes post-AF catheter ablation remains unclear due to inconsistent evidence.

Methods: We systematically reviewed studies from Medline and EMBASE databases from inception to April 2024. Eligible studies must report the association between baseline FMR and risk of AF recurrence post-AF catheter ablation compared to individuals without FMR. Relative Risk (RR) or hazard ratio (HR) and 95% CIs were retrieved from each study and combined using the generic inverse variance method.

Results: Our meta-analysis included 7 cohort studies and found that baseline FMR was associated with a higher risk of AF recurrence compared to those without FMR. The pooled risk ratios (RR) were 1.40 (95% CI 1.11-1.78, I2 = 31%, p = 0.005). No publication bias was identified on the funnel plot.

Conclusions: Our pooled analysis found that patients with FMR who underwent AF catheter ablation had a higher risk of AF recurrence compared to those without FMR. Further research is needed to explore the underlying mechanisms and their clinical implications.

Keyword: Functional mitral regurgitation, Atrial fibrillation, Catheter ablation, Atrial fibrillation recurrence, Systematic review, Meta-analysis