Association of epicardial fat volume with early outcomes in patients undergoing cryoablation for atrial fibrillation.

BACKGROUND

Epicardial fat is a metabolically active visceral adipose tissue that has been implicated in atrial remodeling and atrial fibrillation (AF) pathophysiology. Although increased epicardial fat volume has been associated with AF presence and recurrence after radiofrequency ablation, its role in predicting early outcomes after cryoballoon ablation (CBA) remains incompletely defined. This study aimed to evaluate the association between computed tomography (CT)-derived epicardial fat volume and early arrhythmia recurrence following CBA for paroxysmal AF.

METHODS

We retrospectively analyzed 61 consecutive patients who underwent CBA for paroxysmal AF. Epicardial fat volume was quantified on pre-procedural non-contrast cardiac CT using automated segmentation with predefined attenuation thresholds (- 30 to - 190 HU). Patients were followed for 6 months after a 3-month blanking period. AF recurrence was defined as any documented atrial fibrillation, atrial flutter, or atrial tachycardia lasting ≥ 30 s. Clinical, echocardiographic, laboratory, and procedural variables were compared between patients with and without recurrence. Univariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to identify predictors of recurrence. Multivariable logistic regression analysis was performed including age, body mass index, and epicardial fat volume.

RESULTS

During follow-up, arrhythmia recurrence occurred in 14 patients (23.0%). Patients with recurrence were older and had higher rates of hypertension and coronary artery disease. Epicardial fat volume was significantly higher in patients with recurrence compared with those without recurrence (333.5 ± 82.1 vs. 201.2 ± 66.8 cm³, p < 0.001). In univariate logistic regression analysis, epicardial fat volume was a strong predictor of recurrence (OR 1.02 per cm³, 95% CI 1.01-1.04, p < 0.001), along with age, body mass index, left atrial diameter, coronary artery disease, and lower hemoglobin levels. ROC analysis demonstrated excellent discriminatory ability of epicardial fat volume for predicting recurrence (AUC = 0.891), outperforming body mass index (AUC = 0.836). No major procedural complications were observed.

CONCLUSION

Increased CT-derived epicardial fat volume is strongly associated with early atrial arrhythmia recurrence following cryoballoon ablation for paroxysmal AF. Epicardial fat volume demonstrated excellent predictive performance and may provide incremental value beyond conventional clinical and echocardiographic parameters. Pre-procedural assessment of epicardial fat volume may help identify patients at higher risk for recurrence and guide individualized ablation strategies and follow-up.