Impact of shortening the blanking period to 8 weeks after PVI: Insights from COMPARE-CRYO using continuous rhythm monitoring.

Background: Early recurrences of atrial tachyarrhythmias (ERATs) after pulmonary vein isolation (PVI) are common. While many correlate to late recurrences (LRs), some do not. The impact of ERATs timing is difficult to assess with noninvasive Holter monitoring because of undersampling. The recommended duration of the blanking period (BP) was recently shortened from 90 days to 8 weeks.

Objective: The purpose of this study was to evaluate the impact of ERATs timing after PVI and the effect of a shorter BP by using implantable cardiac monitors for continuous rhythm monitoring.

Methods: This is a prespecified substudy of the Comparison of the POLARx and the Arctic Front cryoballoon for pulmonary vein isolation in patients with symptomatic paroxysmal atrial fibrillation (COMPARE-CRYO) study, which enrolled patients with paroxysmal atrial fibrillation undergoing cryoballoon ablation. All patients underwent implantable cardiac monitor implantation, and the BP was 90 days.

Results: A total of 5285 ERATs episodes occurred in 117 of 201 patients (58%). Freedom from LR was 82% vs 37% in patients without vs with ERATs (P<.001). When patients were classified according to their last episode of ERATs occurring between days 0 and 30, between days 31 and 60, and between days 61 and 90, freedom from LR was 60%, 56%, and 11%, respectively (P<.001). Seven of 201 patients (3.4%) had AF recurrence in the third month after ablation, but not between days 91 and 365, which reclassifies them from ablation success to ablation failure with the shortened 8-week BP.

Conclusion: ERATs after PVI is common. The presence of ERATs in the third month after PVI was highly predictive of ablation failure, supporting the shortening of the BP to 8 weeks; however, the shorter BP reclassifies only 7 (3.4%) of patients to ablation failure instead of ablation success.