Early recurrence of atrial arrhythmia following catheter ablation of atrial tachycardia consecutive to ablation of atrial fibrillation using the updated blanking period.

Background: In patients undergoing catheter ablation of atrial fibrillation (AF), arrhythmia recurrence during the blanking period is usually not considered a failure of treatment. The prognostic significance of early recurrence (ER) of atrial arrhythmia after ablation of atrial tachycardia (AT) subsequent to AF ablation is less certain. Objective: This study aimed to explore the association between early and late recurrence of atrial arrhythmia after ablation of AT subsequent to AF ablation. Methods: Patients undergoing a first ablation of AT subsequent to AF ablation between 2015 and 2021 were included in this retrospective, single-center, observational cohort study. Recurrent atrial arrhythmia was defined as AT or AF lasting more than 30 seconds. Regression models were built to assess the association between early (within 56 days) and late (beyond 56 days) recurrence of AT. Results: A total of 194 patients were included (mean age 67 ± 10 years, 63% male), of whom 71 (37%) had pulmonary vein isolation only, and 123 (63%) had received complex AF ablation during their index procedure. Fifty-two patients (27%) had ER of atrial arrhythmia. During a mean follow-up of 23.6 ± 15.5 months, 118 patients (61%) had late recurrence of atrial arrhythmia (111 with AT, 7 with AF). ER was associated with late recurrence (hazard ratio 1.53; 95% confidence interval 1.05-2.34; Conclusion: One in 4 patients undergoing catheter ablation of AT subsequent to AF ablation had recurrent atrial arrhythmia within 56 days after ablation. ER was associated with late recurrence of atrial arrhythmia.