The Impact of Echocardiographic Epicardial Fat Thickness on Outcomes of Cryoballoon-Based Atrial Fibrillation Ablation

Background: Evidence from previous studies indicates increased epicardial fat volume, measured using computerized tomography, is significantly associated with recurrence of atrial fibrillation (AF) after catheter ablation. This association is most frequently linked to pro-inflammatory cytokine release from epicardial fat tissue. However, there is little data regarding the role of echocardiographically measured epicardial fat thickness (EFT) on catheter ablation outcomes. We aimed to investigate the predictive value of echocardiographically measured EFT on AF recurrence after cryoballoon-based catheter ablation. Methods: A total of 234 patients (51.3% male; mean age, 54.0 ± 10.9 years; 81.2% paroxysmal AF) with symptomatic AF underwent an initial cryoablation procedure. EFT was measured from the parasternal long-axis view at end-systole. A 3-month postablation blanking period was observed. Results: At a median follow-up of 20 (IQR: 13−24) months, 45 patients (19.2%) had developed AF recurrence. EFT thickness was significantly higher among patients with AF recurrence (7.79 ± 2.0 vs. 5.79 ± 1.38, P < 0.001) and was positively correlated with hs-CRP levels (r = 0.381, P < 0.001). Multivariate regression analysis showed EFT (HR: 1.36, 95% CI: 1.10–1.66, P = 0.004), left atrial diameter, and early AF recurrence were independent predictors of AF recurrence. Using a cutoff level of 6.92, preprocedural EFT predicted AF recurrence during follow-up with a sensitivity of 71.1% and specificity of 78.3% (AUC: 0.79; 95% CI: 0.71–0.87, P < 0.001). Conclusion: Echocardiographically measured EFT independently predicted the AF recurrence after cryoablation and was also positively correlated with hs-CRP as an indicator for systemic inflammation. Thus, the association of echocardiographically measured EFT with AF recurrence may be linked to systemic inflammation.