Efficacy of Extensive Ablation for Persistent Atrial Fibrillation With Trigger-Based vs. Substrate-Based Mechanisms　― A Prespecified Subanalysis of the EARNEST-PVI Trial

Background:Extensive ablation in addition to pulmonary vein isolation (PVI) would be effective for modification of non-pulmonary vein (non-PV) substrates, whereas PVI might be sufficient for elimination of PV triggers. This study aimed to test the hypothesis that in patients with reproducible atrial fibrillation (AF) triggered by premature atrial contractions originating only from PVs, PVI alone can be sufficient to maintain sinus rhythm.Methods and Results:This study is a prespecified subanalysis of the EARNEST-PVI randomized controlled trial. This study investigated the efficacy of the PVI-alone strategy (PVI-alone) in comparison with the extensive strategy (PVI-plus) for persistent AF with a trigger-based mechanism vs. a substrate-based mechanism. Patients were stratified into 3 groups based on AF mechanisms: (1) Substrate group (N=236); (2) PV trigger group (N=236); and (3) non-PV trigger group (N=24). The hazard ratios for AF recurrence of the PVI-alone strategy with reference to the PVI-plus strategy were 1.456 (95% confidence interval [CI] [0.864–2.452]) in the substrate group, 1.648 (95% CI 0.969–2.801) in the PV trigger group, and 0.937 (95% CI 0.252–3.488) in the non-PV trigger group. No significant interaction between ablation strategy and AF mechanism was observed (P for interaction=0.748).Conclusions:This study indicated that the efficacies of the PVI-alone strategy compared with the PVI-plus strategy were consistent across persistent AF with trigger-based and substrate-based mechanisms.