Clinical Outcomes After Catheter Ablation in Patients With Structural Heart Disease and Ventricular Fibrillation.

INTRODUCTION: In patients with ischemic cardiomyopathy (ICM), recurrent VF may be treated with catheter ablation by targeting triggering premature ventricular complexes (PVCs) and/or ventricular scar homogenization. Data on optimal ablation strategies in patients with non-ischemic cardiomyopathy (NICM) remain limited. This study aimed to compare ablation strategies and outcomes in patients with recurrent VF due to ICM versus NICM. METHODS AND RESULTS: We retrospectively analyzed consecutive patients with structural heart disease and recurrent VF undergoing catheter ablation. Catheter ablation was performed, including targeting the triggering and/or clinically frequent PVC, targeting any inducible ventricular tachycardia, and/or scar homogenization. Procedural characteristics, arrhythmogenic substrate features, and post-ablation clinical outcomes were compared between ICM and NICM groups. Forty-five patients were included (17 ICM, 28 NICM; mean age 60 ± 15 years; 87% male). PVC ablation was performed in 42% of ICM and 39% of NICM patients, while scar homogenization was undertaken in 76% and 57%, respectively. Left ventricular scar burden, assessed by bipolar and unipolar voltage mapping, was significantly greater in the ICM, whereas the prevalence of abnormal Purkinje potentials was similar between groups. VF-free survival after multiple procedures did not differ between groups, with estimated 1-year rates of 87 ± 9% in ICM and 85 ± 8% in NICM (log-rank p = 0.93). CONCLUSIONS: In patients with NICM and recurrent VF, catheter ablation targeting arrhythmogenic substrate-including unipolar low-voltage regions-combined with PVC ablation yields outcomes comparable to those in ICM, supporting this approach as a reasonable treatment strategy.