Clinical significance of early recurrence after pulmonary vein antrum isolation in paroxysmal atrial fibrillation -- insight into the mechanism.

BACKGROUND: Early recurrence of atrial fibrillation (ERAF) is common after pulmonary vein antrum isolation (PVAI); however, the definition, study population, and lesion set are not uniform in prior studies. We examined ERAF for paroxysmal AF while complying with the definition in the latest guidelines.

METHODS AND RESULTS: We included 471 patients undergoing empirical PVAI for paroxysmal AF. ERAF was observed in 180 patients (38.2%) including 49, 16, and 115 within 3, 4-7 days, and 8-90 days, respectively, after the index procedure. ERAF (hazard ratio 6.872; 95% confidence interval 4.803-9.382; P<0.0001) was the strongest factor associated with recurrence beyond 3 months (LR) in the multivariable model, and ERAF patients had worse outcomes than those without, regardless of the time to the first ERAF episode. There were no significant differences in the prevalence of PV reconnections and non-PV foci among 29 and 62 patients, respectively, who underwent redo procedures for ERAF within and more than 3 months after the index procedure, and 21 who underwent redo procedures for LR. Re-ablation was associated with a greater freedom from LR (HR 0.443; 95% CI 0.230-0.854; P=0.015).

CONCLUSIONS: ERAF occurred in 38.2% of patients and was strongly associated with LR regardless of the time to the first ERAF episode. Re-ablation for ERAF significantly improved the freedom from recurrent atrial arrhythmias, regardless of the time to the first ERAF episode.