Blanking Period after Atrial Fibrillation Catheter Ablation: A Systematic Review and Meta-Analysis

Atrial arrhythmias that recur within the first 3 months after atrial fibrillation (AF) catheter ablation are conventionally attributed to a "blanking period" and not classified as procedural failure. Accumulating evidence suggests that such early recurrences of atrial tachyarrhythmias (ERAT) may instead predict late recurrence, raising concern that the conventional 3-month window overestimates the duration during which recurrences are benign.

To assess the association between ERAT during each of the first 3 months after AF catheter ablation and late recurrence of atrial tachyarrhythmias (LRAT), and whether this association differs by ablation energy source.

We searched Ovid MEDLINE, Embase, and Web of Science without restriction on date or publication status for studies of AF catheter ablation reporting ERAT during defined intervals of the blanking period, stratified by subsequent LRAT status. Ablation energy sources included radiofrequency, cryoballoon, and pulsed field. The exposure was ERAT during the first, second, and third months after ablation, and the outcome was LRAT. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random-effects models.

Twelve studies comprising 7,751 patients (2,505 with LRAT, 5,246 without) were included. Mean follow-up was 22.0 months, mean age 60.7 years, 25.8% were women, 52.5% had paroxysmal AF, mean CHA₂DS₂-VASc score was 2.1, mean left atrial diameter 42.6 mm, and mean left ventricular ejection fraction 58.1%. ERAT was associated with subsequent LRAT, and the strength of this association increased across the blanking period: month 1 (12 studies; OR 1.76, 95% CI 1.01-3.08; p = 0.05), month 2 (10 studies; OR 3.46, 95% CI 2.15-5.57; p < 0.001), and month 3 (10 studies; OR 21.4, 95% CI 10.9-42.2; p < 0.001). The graded association was reproduced within the radiofrequency and cryoballoon subgroups.

ERAT was associated with subsequent LRAT throughout the blanking period, with a graded relationship that strengthened month by month and was strongest in the third month. These findings support a blanking period shorter than the conventional 3 months.