Efficacy of extended antrum ablation based on substrate mapping plus pulmonary vein isolation in the treatment of atrial fibrillation

Introduction and objectives: Pulmonary vein isolation (PVI) technique has become the cornerstone of atrial fibrillation (AF) catheter ablation. The objective of this study was to assess the efficacy and safety of extended antrum ablation based on electrophysiological substrate mapping plus PVI in AF patients who underwent cryoballoon ablation.

Methods: In this observational study, a total of 121 paroxysmal AF patients and 80 persistent AF patients who did not achieve the procedure endpoint after cryoballoon ablation received extra extended antrum ablation (EAA) based on electrophysiological substrate mapping via radiofrequency ablation (EAA group). As a control group (PVI group), among paroxysmal AF and persistent AF patients, we conducted a propensity score-matched cohort, in whom only PVI was completed.

Results: The average follow-up time was 15.27±7.34 months. Compared with PVI group, paroxysmal AF patients in the EAA group had a significantly higher rate of AF-free survival (90.1% vs. 80.2%, p=0.027) and AF, atrial flutter, or atrial tachycardia (AFLAT) -free rate survival (89.3% vs. 79.3%, p=0.031). Persistent AF patients in the EAA group also had a significantly higher rate of AF-free survival (90.0% vs. 75.0%, p=0.016) and AFLAT-free survival (88.8% vs. 75.0%, p=0.029) than PVI group. Complication rates did not significantly differ between both groups, in either paroxysmal AF or persistent AF patients.

Conclusion: Our findings demonstrate that extra extended antrum ablation based on electrophysiological substrate mapping is effective and safe. Moreover, the strategy can improve the outcome of AF cryoablation.