Epicardial And Peri-Atrial Fat Attenuation Predict Recurrence In Patients Undergoing Repeat Catheter Ablation For Refractory Atrial Fibrillation

Background: Identifying factors predictive of atrial fibrillation (AF) recurrence after catheter ablation (CA) can improve patient selection. It has been hypothesized that inflammatory paracrine signaling by metabolically active adipose tissue induces pathologic changes in surrounding cardiovascular tissue. In fact, fat attenuation on CT has been previously associated with AF recurrence after de novo CA. The purpose of this study was to investigate the predictive qualities of epicardial and peri-atrial adipose tissue in a population undergoing repeat CA. We hypothesized that higher epicardial and left peri-atrial fat attenuation would predict recurrence as markers of increased localized inflammation. Methods: The study population consisted of 84 patients with symptomatic, drug and ablation-refractory AF undergoing repeat CA. All patients had a pre-ablation, contrast-enhanced cardiac CT, which was analyzed for mean fat attenuation in Hounsfield units (HU) and left atrial volume using the post-processing program 3D Slicer. Patients were followed for recurrence of atrial tachyarrhythmias after a 3-month blanking period. We performed logistic regression to adjust for age, sex, BMI, hypertension, smoking history, diabetes, obstructive sleep apnea, and left atrial volume index. Results: Repeat CA patients with recurrence (n=52) had a higher epicardial fat attenuation (-84.8 ±5.6 vs -88.1 ±5.2 HU; p=0.009) and peri-atrial fat attenuation (-81.0 ±4.7 vs -83.2 ±4.3 HU; p=0.036) than those without recurrence (n=32) at a mean follow-up period of 26 ±18 months. Logistic regression analysis showed that epicardial fat attenuation (OR 1.21; p=0.005) and peri-atrial fat attenuation (OR 1.27; p=0.007) are predictive of AF recurrence independent of traditional risk factors. Conclusions: Epicardial and left peri-atrial adipose attenuation are predictive of recurrence in patients undergoing repeat CA for AF.