Early arrhythmia recurrence during the blanking period after pulsed-field ablation for atrial fibrillation

Pulmonary vein isolation is a cornerstone in the treatment of atrial fibrillation, with procedural success traditionally assessed after a 3-month "blanking period" to account for early postablation arrhythmias. However, emerging evidence challenges this paradigm, particularly with nonthermal energy modalities such as pulsed-field ablation (PFA), which induce minimal inflammatory response.

The purpose of this study was to assess the prognostic relevance of early recurrence (ER) of atrial arrhythmia during the blanking period after PFA-based pulmonary vein isolation, with a focus on the timing of ER and its association with late recurrence (LR).

In this single-center study, 241 patients with atrial fibrillation underwent first-time PFA and were followed for ≥12 months. ER was defined as any atrial arrhythmia lasting >30 seconds within the first 3 months of ablation. The primary outcome was freedom from LR beyond the blanking period.

ER occurred in 48 (20%) of patients, with 23 (48%) occurring within the first month and 25 (52%) during the second or third month of ablation. LR was significantly more frequent in patients with ER (P < .001), particularly when recurrence occurred after day 30. Multivariable Cox analysis identified ER during the second or third month (hazard ratio 6.1; 95% confidence interval 3.3-11.3) and ER during the first month (hazard ratio 3.6; 95% confidence interval 1.8-7.1) as the strongest independent predictors of LR. A subset of ERs resolved spontaneously.

The timing of ER after PFA strongly predicts LR, supporting reconsideration of the 90-day blanking period. It may be appropriate to shorten the blanking period for PFA, but late ER warrants clinical attention. Larger studies should validate timing-based blanking strategies.