Abstract 10880: Left Atrial Epicardial Adipose Tissue Predicts Atrial Fibrillation Recurrence Following Catheter Ablation

Introduction: Atrial fibrillation (AF) recurrence following catheter ablation (CA) remains high. Epicardial adipose tissue (EAT) is increasingly recognized for its significant role in promoting AF arrhythmogenesis due to its proinflammatory properties and anatomic proximity to the myocardium. We sought to assess whether left atrial (LA) EAT volume is associated with AF recurrence following CA. Methods: EAT was assessed via cardiac MRI using a 3D Dixon sequence (Panel A) in 101 patients undergoing radiofrequency or cryoballoon CA for AF. Patients were followed for AF recurrence. Results: During an average follow-up period of 300 days, post ablation AF recurrence occurred in 31 (30.7%) patients. The median time for AF recurrence following CA was 136 days. LA EAT index was higher in those with recurrence (20.7 [16.9, 30.4] vs 13.7 [10.5, 20.1] mL/m 2 , p < 0.001), and so was LA volume index (66.6 [53.8, 77.5] vs 49.9 [37.7, 62.8] mL/m 2 , p < 0.001). The ROC curve for LA EAT index in the prediction of AF recurrence had an AUC of 0.77 (95% CI 0.68-0.86, p<0.001) and showed an optimal cutoff value of 14.29 mL/m 2 to identify patients at risk of AF recurrence post ablation (Youden’s J statistic = 0.446). Integrating LA EAT with clinical risk factors (age, BMI, AF type and hypertension) provided a better discriminatory performance in predicting AF recurrence than clinical risk factors alone (AUC 0.79 vs 0.65, DeLong test p = 0.044) (Panel B). Cox regression analysis showed LA EAT (HR: 1.088; 95% CI: [1.047-1.13], p <0.001) to be an independent predictor of post ablation AF recurrence. The Kaplan-Meier curve for recurrence free survival showed a significant difference between 2 groups of patients identified by the optimal LA EAT index cut-off of 14.29 mL/m 2 (log rank = 14.79; p < 0.001) (Panel C). Conclusion: EAT quantified using cardiac MRI, a reproducible and widely accessible imaging parameter, is a strong and independent predictor of AF recurrence following CA.