Early recurrence of atrial tachyarrhythmia after catheter ablation and its associations with clinical outcomes, atrial fibrillation burden, and blanking period duration: a post hoc analysis of the CABANA trial

AIMS: Early recurrence of atrial tachyarrhythmia (ERAT) after catheter ablation for atrial fibrillation (AF) is common, yet its prognostic significance and implications for the duration of the blanking period remain uncertain. We aimed to evaluate the association between ERAT and post-ablation clinical outcomes, late arrhythmia recurrence, and AF burden, and to explore the optimal duration of the blanking period. METHODS AND RESULTS: This post hoc analysis included 811 patients from the CABANA trial who underwent catheter ablation and had trial-specific electrocardiographic monitoring data available. ERAT was defined as any episode of AF, atrial flutter, or atrial tachycardia lasting >30 s within the 90-day blanking period. The primary outcome was a composite of all-cause mortality, disabling stroke, serious bleeding, or cardiac arrest. Secondary outcomes included cardiovascular hospitalization and late atrial tachyarrhythmia recurrence. During a median 4 years (IQR 2.5-5.2) follow-up, ERAT occurred in 567 patients (69.9%). Patients with ERAT had higher risks of cardiovascular hospitalization [adjusted hazard ratio (aHR) 1.35, 95% confidence interval (CI) 1.07-1.71] and of the composite outcome of all-cause mortality or cardiovascular hospitalization (aHR 1.33, 95% CI 1.07-1.66), but no increased risk of the primary composite outcome. ERAT was independently associated with late atrial tachyarrhythmia recurrence (aHR 1.35, 95% CI 1.07-1.71). Prognostic relevance varied by timing, with the strongest association observed for ERAT occurring between 60 and 90 days after ablation (aHR 1.80, 95% CI 1.16-2.79). Receiver operating characteristic analysis identified 58 days as the optimal threshold for predicting late arrhythmia recurrence (AUC 0.727). CONCLUSION: ERAT was associated with higher risks of cardiovascular hospitalization and late atrial tachyarrhythmia recurrence in a time-dependent manner, supporting a shorter blanking period to better identify patients at risk of adverse rhythm outcomes.