Electric isolation of the pulmonary veins and posterior left atrium with a single ring of radiofrequency lesions (single-ring isolation [SRI]) may result in fewer
atrial fibrillation (AF) recurrences than wide
antral pulmonary vein isolation (wide
antral isolation [WAI]) by abolishing extravenous AF triggers. The effect of mitral isthmus line (
MIL) ablation on outcomes after SRI has not previously been assessed.
METHODS AND RESULTS: We randomly assigned 220 consecutive patients (58 ± 10 years old; 82% men) with highly symptomatic AF (61% paroxysmal, 39% persistent/longstanding persistent) to undergo either SRI or WAI. Half of each cohort was also randomly allocated to have left lateral
MIL ablation (2 ×2 factorial study design). Patients were followed clinically and with 7-day Holter studies for
arrhythmia recurrences. The primary end points were recurrence of AF and organized atrial
tachyarrhythmias. AF-free survival at 2 years was better after SRI (74% [95% CI, 65%-82%]) than WAI (61% [51%-70%]; P=0.031). Organized atrial
tachyarrhythmia-free survival was similar after SRI and WAI (67% [57%-75%] ersus 64% [54%-72%], respectively, at 2 years; P=0.988).
MIL ablation resulted in better 2-year organized atrial
tachyarrhythmia-free survival (71% [62%-79%] versus 60% [50%-69%]; P=0.07), which approached statistical significance. Survival free of any atrial
arrhythmia after one procedure was not significantly affected by isolation technique or
MIL ablation. Conclusions- SRI resulted in fewer AF recurrences compared with WAI on long-term follow-up but did not reduce the recurrence of all atrial arrhythmias.
MIL ablation may reduce organized atrial
tachyarrhythmia recurrences. Clinical Trial Registration- http://www.anzctr.org.au; ACTRN12606000467538.