One-year outcome and durability of pulmonary vein isolation after prospective use of ablation index for catheter ablation in patients with persistent atrial fibrillation

Abstract

Background: Radiofrequency (RF) catheter ablation for persistent atrial fibrillation (peAF) is associated with less favorable outcomes than for paroxysmal AF (PAF). Recent studies have shown improved clinical outcomes with use of ablation index (AI) targets for pulmonary vein isolation (PVI) in PAF. AI is a novel ablation quality marker that incorporates contact force (CF), time, and power in a weighted formula. This is a single-arm registry to investigate the 1-year efficacy of AF ablation guided by the AI in patients with peAF, and further to evaluate pulmonary vein reconduction at repeat electrophysiology study in case of recurrent AF.

Methods: In total, 55 consecutive patients (69 ± 10 years, 55% male, median time since first AF diagnosis: 31 months (Q1-Q3: 10-70)) with peAF underwent AIguided PVI using a CF surround-flow catheter. AI targets were 600 for anterior and 450 for roof/posterior/inferior antral segments. Patients were monitored for atrial tachyarrhythmia recurrence using 5-day Holter-ECG recordings at 3, 6, and 12 months.

Results: The median procedure time was 173 min (Q1-Q3: 152-204). The median fluoroscopy time was 4 min (Q1-Q3: 3-6) and the median fluoroscopy dose was 2.64 Gy/cm2 (Q1-Q3: 1.04-3.99). The median ablation time was 57 min (Q1-Q3: 47-63). At 12 months, 42% of the patients were in sinus rhythm. AF recurrence was seen in 58% of patients. No major complications occurred.

Conclusions: RF ablation using AI in peAF is a feasible and safe technique. At 1 year, AI-guided ablation was associated with AF recurrence in 58% of the patients.

Keywords: Ablation index; Catheter ablation; Persistent atrial fibrillation; Pulmonary vein isolation.