Impact of Rotor Ablation in Nonparoxysmal Atrial Fibrillation Patients: Results From the Randomized OASIS Trial

Background Nonrandomized studies have reported focal impulse and rotor modulation (FIRM)-guided ablation to be superior to pulmonary vein antrum isolation (PVAI) for persistent atrial fibrillation and long-standing persistent atrial fibrillation. Objectives This study sought to compare efficacy of FIRM ablation with or without PVAI versus PVAI plus non-PV trigger ablation in randomized persistent atrial fibrillation and long-standing persistent atrial fibrillation patients. Methods Nonparoxysmal atrial fibrillation (AF) patients undergoing first ablation were randomized to FIRM only (group 1), FIRM + PVAI (group 2) or PVAI + posterior wall + non-PV trigger ablation (group 3). Primary endpoint was freedom from atrial tachycardia/AF. The secondary endpoint was acute procedural success, defined as AF termination, ≥10% slowing, or organization into atrial tachycardia. Results A total of 113 patients were enrolled at 3 centers; 29 in group 1 and 42 each in groups 2 and 3. Group 1 enrollment was terminated early for futility. Focal drivers or rotors were detected in all group 1 and 2 patients. Procedure time was significantly shorter in group 3 versus groups 1 and 2 (p < 0.001). In groups 1 and 2, acute success after rotor-only ablation was achieved in 12 patients (41%) and 11 (26%), respectively. After 12 ± 7 months’ follow-up, 4 patients (14%), 22 (52.4%), and 32 (76%) in groups 1, 2, and 3, respectively, were AF/atrial tachycardia–free while off antiarrhythmic drugs (log-rank p < 0.0001). Group 3 patients experienced higher success compared with groups 1 (p < 0.001) and 2 (p = 0.02). Conclusions Outcomes were poor with rotor-only ablation. PVAI + rotor ablation had significantly longer procedure time and lower efficacy than PVAI + posterior wall + non-PV trigger-ablation.