Reverse Cardiac and Epicardial Adipose Tissue Remodeling Following Catheter Ablation of Paroxysmal Atrial Fibrillation in HFpEF

Background: Catheter ablation (CA) with pulmonary vein isolation is an established treatment for atrial fibrillation (AF). Epicardial adipose tissue (EAT) has been implicated in AF pathophysiology, but data on periatrial EAT and cardiac structural changes after CA in patients with heart failure with preserved ejection fraction (HFpEF) remain limited. Methods: We prospectively included 43 patients with paroxysmal AF and HFpEF undergoing radiofrequency CA. Cardiac magnetic resonance (CMR) was performed before ablation and after 6 months to quantify periatrial EAT volume and left ventricular mass (LVM) as prespecified primary endpoints, alongside secondary exploratory structural and functional parameters. Results: The study included 43 patients (74.4% male; mean age 60.5 ± 10.4 years). At 6-month follow-up, both primary endpoints improved significantly: periatrial EAT volume decreased from 28.8 ± 6.3 to 20.3 ± 5.9 mL (p < 0.001), and LVM decreased from 102 (95–115) to 97 (89–104) g/m2 (p = 0.003). Exploratory analyses demonstrated favorable reverse cardiac remodeling, including reductions in left atrial area (LAA), left ventricular end-diastolic and end-systolic volumes, right ventricular end-systolic volume, and an increase in left ventricular stroke volume. Greater reduction in periatrial EAT volume correlated with more pronounced reverse cardiac remodeling, particularly with reductions in LVM (ρ = 0.48; p < 0.001) and LAA (ρ = 0.44; p = 0.003), with similar associations observed across other left ventricular remodeling parameters. Conclusions: In patients with paroxysmal AF and HFpEF, CA was associated with significant reductions in periatrial EAT volume and LVM, accompanied by favorable structural changes on CMR. These findings are consistent with reverse cardiac remodeling following CA and support further investigation of its structural effects in this patient population.