Although pulmonary vein isolation (PVI) has become the cornerstone ablation procedure for atrial fibrillation (AF), the optimal ablation procedure for persistent and long-standing persistent AF remains elusive. Targeting spatio-temporal electrogram dispersion in a tailored procedure has been suggested as a potentially beneficial alternative to a conventional PVI-only procedure. In this multicenter, randomized, controlled, double-blind, superiority trial, patients with drug-refractory persistent AF were randomly assigned to a tailored ablation procedure targeting areas of spatio-temporal dispersion, as detected by an artificial intelligence (AI) algorithm, in addition to PVI (tailored arm, n = 187, 23% women) or to a conventional PVI-only procedure (anatomical arm, n = 183, 19% women). The primary efficacy endpoint was freedom from documented AF with or without antiarrhythmic drugs at 12 months after a single ablation procedure. Secondary endpoints included freedom from any atrial arrhythmic events, and the secondary composite safety endpoint consisted of death, cerebrovascular events, or treatment-related serious adverse events. One year post-procedure, the trial met its primary efficacy endpoint, which was achieved in 88% of patients in the tailored arm compared with 70% of patients in the anatomical arm (log-rank P < 0.0001 for superiority). However, no significant difference between arms was observed for the freedom from any atrial arrhythmia endpoint after one ablation. The safety endpoint did not differ between arms, with procedure and ablation times being twice as long in the tailored arm. These results show that AI-guided ablation of spatio-temporal dispersion areas in addition to PVI is superior to PVI alone in eliminating AF at 1-year follow-up in patients with persistent and long-standing persistent AF. Ablation of subsequent organized atrial tachycardias may be needed to maintain sinus rhythm long term. ClinicalTrials.gov identifier: NCT04702451 .

Background: Recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI) are mainly due to pulmonary vein reconnection. However, a growing number of patients have AF recurrences despite durable PVI. The optimal ablative strategy for these patients is unknown. We analyzed the impact of current ablation strategies in a large multicenter study. Methods: Patients undergoing a redo ablation for AF and presenting durable PVI were included. The freedom from atrial arrhythmia after pulmonary vein-based, linear-based, electrogram-based, and trigger-based ablation strategies were compared. Results: Between 2010 and 2020, 367 patients (67% men, 63±10 years, 44% paroxysmal) underwent a redo ablation for AF recurrences despite durable PVI at 39 centers. After durable PVI was confirmed, linear-based ablation was performed in 219 (60%) patients, electrogram-based ablation in 168 (45%) patients, trigger-based ablation in 101 (27%) patients, and pulmonary vein-based ablation in 56 (15%) patients. Seven patients (2%) did not undergo any additional ablation during the redo procedure. After 22±19 months of follow-up, 122 (33%) and 159 (43%) patients had a recurrence of atrial arrhythmia at 12 and 24 months, respectively. No significant difference in arrhythmia-free survival was observed between the different ablation strategies. Left atrial dilatation was the only independent factor associated with arrhythmia-free survival (HR, 1.59 [95% CI, 1.13–2.23]; P =0.006). Conclusions: In patients with recurrent AF despite durable PVI, no ablation strategy used alone or in combination during the redo procedure appears to be superior in improving arrhythmia-free survival. Left atrial size is a significant predictor of ablation outcome in this population.