The Southern Brazilian Registry of Atrial Fibrillation (SBR-AF Registry): Predictors of Atrial Arrhythmia Recurrence after First-Time Catheter Ablation

Background: Treatment of atrial fibrillation (AF) with catheter ablation (CA) has evolved significantly. However, real-world data on long-term outcomes are limited, particularly in low- and middle-income countries. Objective: This multicenter prospective cohort of consecutive patients aimed to evaluate the safety and efficacy of first-time CA for AF in Southern Brazil from 2009 to 2024. Methods: The primary outcome was any atrial tachyarrhythmia (ATA) recurrence. Multivariable Cox proportional hazards model assessed independent predictors of recurrence. Results: Among 1,043 patients (mean age 67.3 +/- 11.3 years, 27.9% female), 75.5% had paroxysmal AF. At a median follow-up of 1.4 (1.0- 3.4) years, 21.4% had ATA recurrence. Recurrence rates were 18.6% for paroxysmal and 29.8% for persistent AF, and 67.3% of events occurred within the first year after CA. Predictors of recurrence were persistent AF at baseline (hazard ratio [HR] 1.57, 95% confidence interval [CI] 1.15-2.13; p = 0.004), enlargement of left atrial diameter (HR 1.03, 95% CI 1.00-1.05; p = 0.033), and higher EHRA score of AF symptoms (HR 1.60, 95% CI 1.18-2.18; p = 0.003). Recurrence rates decreased over time according to the procedure's calendar year, with a 9% relative reduction per consecutive year (HR 0.91; p < 0.001). There was a 2.1% procedure-related adverse event rate. Conclusions: In the largest cohort study of consecutive AF ablations in Latin America, predictors of ATA recurrence were related to later stages of AF. Complication and recurrence rates were comparable to those in high-income countries, underscoring the global applicability of CA for AF management.