CE-452778-4 SKIPPING ABLATION LESIONS DOES NOT AFFECT ATRIAL ARRHYTHMIA RECURRENCE AFTER PULMONARY VEIN ISOLATION IN PERSISTENT AF: A DECAAF II SUBSTUDY

Abstract

Skip lesions are often performed during ablation for atrial fibrillation (AF) either because of difficulty in catheter positioning or commonly to minimize thermal stacking. There is no clear consensus whether skipping lesions during Pulmonary Vein Isolation (PVI) affects atrial arrhythmia (AA) recurrence after the procedure. We sought to study the effect of skip lesions on AA recurrence in pts undergoing a first time PVI only procedure for persistent atrial fibrillation (PrAF). The DECAAF II Trial was a prospective randomized controlled trial of pts with PrAF undergoing first time ablation. Of 408 pts in the control group (PVI alone), 189 were excluded due to having missing ablation lesions data or having underwent Cryoballoon ablation. The remaining 219 pts constitute the study population. From those pts, 22,377 ablation lesions with their respective space (x, y, z) and time coordinates were collected (figure). Two time-consecutive lesions were considered skip lesions if the Euclidian distance between them was >10 millimeters. Pts were instructed to provide single-lead home ECG strips once daily and during symptoms. A survival analysis using log-rank was performed to assess for atrial arrhythmia through 365 days following a 90-day blanking period. At baseline, the mean pt age was 62 yrs, and 78% were male. There were 15,805 non-skip lesions and 6,572 skip lesions. The median skip lesions percentage per pt was 40%. Skip lesions had increased impedance drop (10.94±16 vs 9.19±13, p<0.001), and force-time interval (266±297 vs 224±219, p<0.001), compared to non-skip lesions. There was similar ablation index reached between skip and non-skip lesions (392.7±97 vs 395.6±110, p=0.62). The percentage of skip lesions was not predictive of AA recurrence when studied as a continuous variable or when modeled using different cutoff threshold values (p=0.45). Similarly, no differences were seen in the percentage of skip lesions in pts with AA recurrence and those without (35 vs 36%, p=0.99). Also, no difference was seen in procedural time and follow-up ablation scar in pts with >40% skip lesions vs <40%. The use of skip lesions was very common in the present point-by-point ablation era. The use of skipped lesions was not related to worsened long-term outcomes after PVI in pts with PrAF.