Impact of rotor ablation in non-paroxysmal AF patients: Findings from the per-protocol population of the OASIS trial at long-term follow-up.

The objective of this study was to evaluate the long-term efficacy of FIRM ablation with PVAI vs PVAI plus posterior wall isolation (PWI) and non-PV trigger ablation in persistent (PeAF) and long-standing persistent AF (LSPAF) patients. The procedure time was recorded to be 180.6 ±â€¯35.9 and 124.03 ±â€¯45.4 minutes in the FIRM+PVI and PVI + PWI + non-PV trigger ablation group respectively. At 24-month follow-up, 24% (95% CI 8.7%-37.8%) in the FIRM-ablation group and 48% (95% CI 27.6-63.3%) in the non-PV trigger ablation group remained arrhythmia-free off-antiarrhythmic drugs after a single procedure. Clinical Trial Registration:ClinicalTrials.gov (Identifier: NCT02533843).

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. (Outcome of Different Ablation Strategies in Persistent and Long-Standing Persistent Atrial Fibrillation [OASIS]; NCT02533843).

Acute and early outcomes of focal impulse and rotor modulation (FIRM)-guided rotors-only ablation in patients with nonparoxysmal atrial fibrillation.

BACKGROUND: Focal impulse and rotor modulation (FIRM)-guided ablation targets sites that are thought to sustain atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to evaluate the acute and mid-term outcomes of FIRM-guided only ablation in patients with nonparoxysmal AF. METHODS: We prospectively enrolled patients with persistent and long-standing persistent (LSP) AF at three centers to undergo FIRM-guided only ablation. We evaluated acute procedural success (defined as AF termination, organization, or ≥10% slowing), safety (incidence of periprocedural complications), and long-term success (single-procedure freedom from atrial tachycardia [AT]/AF off antiarrhythmic drugs [AAD] after a 2-month blanking period). RESULTS: Twenty-nine patients with persistent (N = 20) and LSP (N = 9) AF underwent FIRM mapping. Rotors were presents in all patients, with a mean of 4 ± 1.2 per patient (62% were left atrial); 1 focal impulse was identified. All sources were successfully ablated, and overall acute success rate was 41% (0 AF termination, 2 AF slowing, 10 AF organization). There were no major procedure-related adverse events. After a mean 5.7 months of follow-up, single-procedure freedom from AT/AF without AADs was 17%. CONCLUSION: In nonparoxysmal AF patients, targeted ablation of FIRM-identified rotors is not effective in obtaining AF termination, organization, or slowing during the procedure. After mid-term follow-up, the strategy of ablating FIRM-identified rotors alone did not prevent recurrence from AT/AF.