Epicardial adipose tissue and ablation outcomes in obese patients with paroxysmal atrial fibrillation: A comparison of pulsed field and radiofrequency ablation.

Background: Preclinical studies showed inconsistent results regarding the influence of adipose tissue on effective pulsed field ablation (PFA), raising questions about its efficacy in patients with elevated epicardial adipose tissue (EAT) levels. Objective: Elevated EAT levels may lead to higher atrial fibrillation (AF) recurrence rates after pulmonary vein isolation using PFA than high-power, short-duration radiofrequency (RF) ablation. Methods: 103 patients with body mass index of >29 kg/m2 with paroxysmal or short-term persistent AF who underwent first-time AF ablation were prospectively enrolled (PFA n = 41; RF n = 62). All patients received preablation photon-counting computed tomography imaging to volumetrically quantify left and right atrial EAT levels. PFA was performed using a pentaspline catheter, and RF ablation was performed using high-power, short-duration energy. Results: Median EAT volumes were 71.85 mL (interquartile range 50.35-93.35 mL) in the RF group and 65.61 mL (interquartile range 40.45-90.8 mL) in the PFA group (P = .1352). Median follow-up was 367 days, excluding a 6-week blanking period. Atrial arrhythmia recurrence at 1 year was 33.87% in the RF group vs 17.07% in the PFA group (P = .077). Cox regression showed that, in the PFA group, left atrial EAT was the only significant predictor of recurrence (hazard ratio 1.06; 95% confidence interval 1.01-1.12; P = .022), corresponding to a 6.2% increased risk per mL. In the RF group, left atrial EAT was not significantly associated with recurrence (hazard ratio 1.00; 95% confidence interval 0.97-1.03; P = .846). Conclusion: PFA showed good 1-year results after pulmonary vein isolation in patients with a body mass index of >29 kg/m2. However, EAT may have a more significant impact on AF recurrences after PFA than RF ablation. Trial Registration Number: NCT06559787.