Effects of Isolability of Non-Pulmonary Vein Foci on the Efficacy of Ablation for Atrial Fibrillation

Abstract

Objective: This study aimed to evaluate the effects of isolability of non-PV foci on the efficacy of atrial fibrillation (AF) ablation. Background: AF mainly originates from the pulmonary vein (PV). Meanwhile, some AF triggers originate from other sites, namely non-PV foci, which are related to recurrence after AF ablation. Methods: Overall, 1855 patients with AF (age, 64.6±10.9 years; 82% paroxysmal) underwent PV isolation, followed by induction and ablation of non-PV foci. Overall, 545 (29%) patients had non-PV foci; these patients were categorized into those with isolable non-PV foci (n=193, 36%) and those with non-isolable non-PV foci (n=347, 64%). Results: During a mean follow-up of 31.1±15.5 months, recurrence was higher in the non-isolable group than in the isolable group (33% vs. 19%, P<0.01). Kaplan-Meier analysis revealed that the 1-year clinical outcome was significantly better in the isolable group than in the non-isolable group (88.3% vs. 78.6%, P<0.001; hazards ratio [HR], 0.53; 95% confidence interval [CI], 0.37-0.77). This outcome was not inferior to that of patients without non-PV foci (88.3% vs. 90.7%, P=0.86). The non-isolable group showed poorer clinical outcomes than patients without non-PV foci (78.6% vs. 90.7%, P<0.001; HR, 1.36; 95% CI, 1.22-1.52). Cox regression analysis revealed that isolability (HR, 0.60; 95% CI, 0.39-0.92) and unmappability (HR, 1.82; 95% CI, 1.15-2.88) of non-PV foci were significant predictors of arrhythmia recurrence. Conclusions: Isolability of non-PV foci was a significant factor in terms of achieving better clinical outcomes following AF ablation in patients with non-PV foci.