Intraprocedural atrial flutter transition predicts arrhythmia-free survival after "2C3L Plus" ablation for...

Long-standing persistent atrial fibrillation (LSPAF) remains a challenge of catheter ablation. The efficiency and optimal procedural endpoints of "2C3L plus" approach-a strategy combining pulmonary vein isolation (PVI) with linear and complex fractionated atrial electrogram (CFAEs) ablation-is unclear.

This single-center, retrospective cohort study included 260 consecutive patients with LSPAF (defined as continuous AF lasting > 12 months) who underwent de novo radiofrequency catheter ablation between January 2020 and January 2022. All patients received a standardized "2C3L plus" strategy. The primary endpoint was freedom from any documented atrial tachyarrhythmia lasting >30 s, off antiarrhythmic drugs, at 1-year follow-up. Predictors of recurrence were analyzed using multivariable Cox regression analysis.

Intraprocedural atrial fibrillation (AF) termination was achieved in 103 of 260 (39.6%) patients and 90 (34.6%) patients converted to atrial flutter (AFL) during ablation. Acute termination of AF directly to sinus rhythm (SR) was not associated with a lower risk of recurrence (adjusted HR: 0.765, 95% CI: 0.410-1.428, P = 0.400). However, intraprocedural conversion from AF to AFL was associated with significantly reduced recurrence risk (Uni: HR: 0.319, 95% CI: 0.142-0.714, P = 0.005; adjusted HR: 0.306, 95% CI: 0.133-0.704, P = 0.005). Further analysis revealed that the sequential intraprocedural conversion of AF-AFL-SR during ablation was a strong and independent predictor of arrhythmia-free survival (Uni: HR: 0.275, 95% CI: 0.108-0.696, P = 0.006; adjusted HR: 0.305, 95% CI: 0.119-0.784, P = 0.014).

In patients with LSPAF undergoing extensive "2C3L Plus" substrate ablation, the intraprocedural organization of AF-AFL-SR, rather than AF termination itself, emerged as a powerful independent predictor of 1-year arrhythmia-free survival, suggesting its value as a more meaningful prognostic endpoint.