Abstract 15904: Acute Outcomes in Persistent and Long-standing Persistent Atrial Fibrillation Patients Undergoing Rotor Ablation

Introduction: Focal impulse and rotor modulation (FIRM)-guided ablation targets localized sources that are thought to sustain AF. In previous reports, it has been shown that FIRM is effective in terminating or organizing AF. We sought to evaluate the acute success of FIRM in patients with persistent and LSP AF undergoing ablation in our centers. Methods: This was a multicenter prospective observational study. FIRM was performed alone or before conventional ablation. Rotors were ablated as confirmed by their absence during remapping and acute success was defined as AF termination, organization or slowing 10%. Results: 57 patients were enrolled (mean age 63 ± 10; 7% LSP). Rotors-only ablation was performed in 56% of patients, and preceded conventional ablation in 44%. There were no major periprocedural adverse events. No focal impulses were found, while rotors were present in all patients (3.9 ± 1.2 per patient; 66% in the LA). In the RA, the majority of rotors were in the lateral wall (53%) and in the septum (30%). In the LA, most of the rotors were in proximity of the pulmonary veins (48%), with the second most common locations being around the mitral annulus or in the septum (17% and 13% respectively). Mean procedural time for FIRM only procedures was 226 ± 52 minutes vs a median of 210 (168-240) minutes for FIRM + conventional ablation procedures (p = NS). Overall acute success was achieved in 35% of patients (3% AF termination, 16% AF organization, 16% AF slowing) with a mean RF time to complete FIRM ablation of 30 ± 15 minutes; no difference in acute success was found when comparing persistent to LSP patients (28% vs 50%; p = NS). Conventional ablation following FIRM did not significantly increase the rate of acute success (1 additional patient converted to sinus rhythm during pulmonary vein isolation). Conclusion: Rotors were present in all patients undergoing ablation for non-paroxysmal AF, most commonly the right atrial lateral wall, septum or around the pulmonary veins. Their ablation was not effective in obtaining AF organization/termination during the procedure.