Timing of early recurrence of atrial fibrillation during the blanking period after catheter ablation for persistent atrial fibrillation and implications for long-term success: a multicentre study

Abstract Background After catheter ablation (CA) for atrial fibrillation (AF), early recurrences of AF (ERAF) that occur within a 90-day post-ablation "blanking period" are considered to represent transient post-ablation pro-arrhythmia. Purpose To determine if the timing of early recurrence of AF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence after CA for persistent AF (PsAF). Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018. All patients had undergone pre-CA DCCV. Incidences of ERAF during the post-CA blanking period were reviewed, and patients were categorised into three groups based on the timing of last episode of ERAF during the blanking period: (1) no ERAF (reference population); (2) last ERAF <30 days post-CA; (3) last ERAF 31-90 days post-CA. The primary outcome was long-term recurrence of atrial arrhythmia, i.e. time to first recurrence of atrial arrhythmia occurring beyond the first 90 days after CA. Patients who had ERAF and exited the blanking period in AF (i.e. those with immediate recurrence at 90 days) were excluded from this analysis. Results 331 patients were identified from five centres. 206 patients had no ERAF during follow-up, 124 patients had ERAF during the blanking period, and in one patient the presence of ERAF was not documented. Of the 124 patients experiencing ERAF during the 90-day post-CA blanking period, the timing of the last episode was known in 122 patients (Table 1). Of these, 58 patients exited the 90-day blanking period in AF and were excluded. Over median post-CA follow-up of 590 days, 147 patients (54%) experienced the primary outcome. Compared with Group 1 (no ERAF), ERAF within each of the time periods was associated with a statistically significant progressively increased risk of long-term recurrence (Group 2, last ERAF <30 days post-CA: hazard ratio [HR] 1.95 [95% CI 1.15-3.31]; Group 3, last ERAF 31-90 days post-CA: HR 4.86 [95% CI 2.13-11.08]; Figure 1). Conclusion ERAF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence, with later recurrence within the 90-day period conferring greater risk. Patients with ERAF during the blanking period may need to be considered for earlier repeat intervention where clinically appropriate.