Body mass index, acute atrial fibrillation termination, and long-term recurrence after catheter ablation for persistent atrial fibrillation: insights from a large contemporary cohort.

BACKGROUND: Obesity is a modifiable risk factor for atrial fibrillation (AF), but its relationship with acute procedural response and long-term rhythm durability after ablation for persistent AF (PeAF) remains incompletely defined. OBJECTIVE: To evaluate the association of body mass index (BMI) with acute AF termination and long-term atrial arrhythmia recurrence after first-time radiofrequency catheter ablation for PeAF. METHODS: We analyzed prospective data from 7,559 consecutive patients with clinically documented PeAF undergoing first-time radiofrequency catheter ablation between January 2018 and March 2025. Patients were classified according to World Health Organization BMI categories. The primary outcome was atrial arrhythmia recurrence after a 3-month blanking period. RESULTS: During a median follow-up of 41 months, atrial arrhythmia recurrence occurred in 3,494 patients (46.2%). In the fully adjusted model, higher BMI was associated with recurrence as a continuous variable (HR 1.03, 95% CI 1.02-1.04). Compared with normal-weight patients, overweight and obese patients had higher recurrence risks (HR 1.15, 95% CI 1.06-1.24; and HR 1.31, 95% CI 1.18-1.45, respectively). Acute AF termination occurred in 832 patients (11.0%) and decreased with increasing BMI. Higher BMI was associated with lower odds of acute AF termination (OR 0.95, 95% CI 0.93-0.97). Findings were consistent across sensitivity analyses. CONCLUSION: In patients with PeAF undergoing first-time radiofrequency ablation, higher BMI was associated with lower acute AF termination and increased long-term recurrence. BMI may serve as a practical marker for preprocedural risk stratification.