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 10 th 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 Clinical Perspectives What is new? This is the first randomized multi-center study to compare two different ablation strategies in AF patients with durable PVI. Empirical LAAI was not associated with better outcome in comparison to low-voltage area ablation. What are the clinical implications? LAAI should not be advocated as a stand-alone ablation strategy for patients with AF recurrences after prior ablation. The patient with AF recurrence after prior catheter ablation should be informed that if all PVs are found durably isolated the optimal ablation strategy remains uncertain.