Low-Voltage-Area Ablation in Paroxysmal Atrial Fibrillation: Extended Follow-Up Results of the Volcano Trial

Abstract

Objectives: To compare long-term atrial fibrillation (AF)/atrial tachycardia (AT) recurrence rates and types of recurrent-atrial-tachyarrhythmia between treatment cohorts enrolled in the randomized controlled VOLCANO trial. \n \nBackground: Although VOLCANO trial demonstrated comparable 1-year rhythm outcomes between patients with and without ablation targeting low-voltage areas (LVAs) in addition to pulmonary vein isolation among paroxysmal AF patients with LVAs, efficacy of LVA ablation on long-term outcomes are still unknown. \n \nMethods: Total of 402 paroxysmal AF patients were divided into 4 groups based on the results of voltage mapping: Group A, no LVA (n=336); group B, LVA ablation (n=30); group C, LVA presence without ablation (n=32); and group D, incomplete voltage map (n=4). \n \nResults: At 25 (23, 31) months after the initial ablation, AF/AT recurrence rates were 19% in group A, 57% in group B, 59% in group C, and 100% in group D. Recurrence rates were higher in patients with LVAs than those without (group A vs. B+C, p<0.0001), and were comparable between those with and without LVA ablation (group B vs. C, p=0.83). Among patients who underwent repeat ablation, ATs were more frequently observed in patients with LVAs (Group B+C, 50% vs. A, 14%, p<0.0001). In addition, LVA ablation increased the incidence of AT development (group B, 71% vs. C, 32%, p<0.0001), especially biatrial tachycardia (20% vs. 0%, p=0.01). \n \nConclusion: Patients with LVAs demonstrated poor long-term rhythm outcomes irrespective of LVA ablation. ATs were frequently observed in patients with LVAs, and LVA ablation might exacerbate iatrogenic ATs. \n \nClinical Trial Registration: UMIN-CTR, https://www.umin.ac.jp/ctr/, UMIN000023403