Early recurrence of atrial tachyarrhythmia indicates pulmonary vein reconduction independent of blanking period duration in the RACE-AF trial

Introduction: Atrial tachyarrhythmia recurrence during the blanking period (early ATA) after pulmonary vein isolation (PVI) is associated with an increased risk of later recurrence, but its relationship with pulmonary vein reconduction (PVR) is poorly understood. The objective of the present study was to evaluate the relationship between early ATA and PVR. Second, to provide data on the optimal blanking period by (a) evaluating how the predictive values of ATA for PVR are affected by blanking period duration, and (b) assessing the temporal development in atrial fibrillation (AF) burden. Methods: In this RACE-AF substudy, 91 patients with paroxysmal AF undergoing PVI randomized to radiofrequency or cryoballoon ablation were included. All patients received an implantable cardiac monitor and underwent a protocol-mandated repeat procedure after 4–6 months for assessment of PVR. ATA ≥ 30 s. ≤ 90 days after PVI constituted early ATA. Results: PVR was found in 37/54 (69%) patients with early ATA and in 11/37 (30%) patients without (p <.001). The positive predictive value of ATA for PVR was independent of blanking period duration (range 0–90 days). In both patients with and without PVR, AF burden was higher in the first month after PVI, but AF burden from the second month was similar to AF burden after the conventional blanking period. Conclusion: Early ATA indicates PVR, and the positive predictive value is independent of the blanking period duration. Altogether, the results of this study support substantially shortening the blanking period after PVI for paroxysmal AF.