Defining the Blanking Period, Using Continuous ECG Monitoring, Following Cryoballoon Pulmonary Vein Isolation

Background Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. A blanking period (BP) of 3 months is used in clinical trials and practice. However, the optimal BP duration following PVI remains undefined. Objective To objectively define, using continuous monitoring via an implantable loop recorder (ILR), the optimal BP duration post cryoballoon (CB) PVI. Methods We enrolled consecutive patients who had CB PVI and an ILR. We determined the time of their last confirmed episode of AF within BP. This was then correlated with AF recurrence in the first year after ablation. Results There were 210 patients (66 ± 9 years; 138 [66%] male; 116 [55%] PAF; CHA2DS2-VASc 2.5 ± 1.6). We defined 4 distinct groups based on the last AF episode within the BP: (1) no AF days 0-90 (n=96 [46%]); last AF (2) 0-30 days (n=46 [22%]); (3) 31-60 days (n=18 [9%]); and (4) 61-90 days (n=50 [24%]). Following the 3-month BP, 101 (48%) patients had AF recurrence at 160 ± 86 days. Compared to patients with no AF in the BP, those with recurrent AF and AF burden > 0% after 30 days post-ablation had a significantly greater AF recurrence during long-term follow-up (p=0.001). Conclusion Our data show that the ∼1/3 of patients in whom AF occurs and have a burden of > 0% after the first month post PVI are at significantly higher risk of long-term recurrent AF. We therefore suggest that the BP be limited to a month post CB PVI.