Ablation STrategies for Repeat PrOcedures in Atrial Fibrillation Recurrences despite Durable Pulmonary Vein Isolation. ASTRO - AF Trial

Background: Ablation strategies for patients with symptomatic atrial fibrillation (AF) and isolated pulmonary veins (PV) vary and their impact on arrhythmia recurrence remains unclear. This prospective randomized German multi-center trial sought to compare two ablation strategies in this patient cohort. Methods: Patients with AF despite durable PV isolation were randomly assigned at seven centers to undergo low-voltage area (LVA) ablation using 3D mapping and irrigated radiofrequency current ablation (group A) or empirical left atrial appendage isolation (LAAI) utilizing the cryoballoon (CB) followed by staged interventional LAA closure (group B). The primary endpoint was freedom from atrial tachyarrhythmias between 91 and 365 days after index ablation. The study was powered for superiority of LAAI compared to LVA. Results: Patients (40% female, mean age 68.8±8 years) with paroxysmal (32%) or persistent AF (68%) were randomized to undergo LVA ablation (n=79) or CB guided LAAI (n=82). After a planned interim analysis enrollment was halted on January 10th 2023. In the LAAI group 77/82 LAAs were successfully isolated with subsequent LAAC in 57 patients. Procedure related complications occurred in 4 (5%) and 11 (13.5%) patients in group A and B, respectively (P=0.10). The median follow-up was 367 (IQR 359-378) days. The Kaplan Meier point estimate for the freedom from a primary endpoint event was 51.7% (CI 40.9-65.4%) for group A and 55.5% (CI 44.4-69.2%; p=0.8069). Conclusions: The present study did not detect superiority of CB guided LAAI over LVA ablation in patients with AF despite durable PVI. It was registered at https://clinicaltrials.gov/study/NCT04056390