Early atrial fibrillation recurrence post catheter ablation: Analysis from insertable cardiac monitor in the era of optimized radiofrequency ablation

Background Early recurrence of atrial tachyarrhythmia (ERAT) is associated with ablation-induced pro-arrhythmogenic inflammation; however, existing studies used intermittent monitoring or non-optimized RF applications (non-contiguous or without ablation index target value). Objective We aimed to investigate the relationship between ERAT and late recurrence based on insertable cardiac monitor (ICM) data. Methods We compiled data from Close-To-Cure and Close Maze studies, which enrolled patients who underwent RF ablation for paroxysmal or persistent AF. All patients were implanted with an ICM 2-3 months prior to ablation. Results We studied 165 patients [104 with paroxysmal and 61 with persistent AF]. Over the 1-year follow-up period, 41/165 patients experienced late recurrence. The risk of late recurrence was higher in patients experiencing ERAT (HR 6.2, 95%CI 3.0-13.0), with negative and positive predictive values of 90.5 and 45.7%. The median burden of AF during the blanking period was significantly higher in patients with late recurrence (7.9 [0.0–99.6]%) compared to those without recurrence (0.0 [0.0–6.0]%; p<0.001). For each 1% increase in the AF burden during the blanking period, late recurrence increased by 4.6% (HR 1.046, 95%CI 1.035-1.059). The best trade-off for predicting AF from ERAT occurrence was an AF burden of 0.6% and the last ERAT at 64 days. Conclusion In patients ablated for paroxysmal and persistent AF with a durable RF lesion set and implanted with a continuous monitoring device, post-ablation early AF recurrence and burden significantly predict late recurrence. The post AF ablation blanking period should be reduced to 2 months.