Epicardial adipose tissue affects the efficacy of left atrial posterior wall isolation for persistent atrial fibrillation

BACKGROUND: Epicardial adipose tissue (EAT) contributes to atrial fibrillation (AF). However, its impact on the efficacy of left atrial posterior wall isolation (LAPWI) is unclear. METHODS: Forty‐four nonparoxysmal AF patients underwent LAPWI after pulmonary vein isolation. EAT overlap on LAPWI was assessed by fusing computed tomography images with electro‐anatomical mapping. RESULTS: During the 21 ± 7 months of follow‐up, AF recurred in 10 patients (23%). The total and left atrial EAT volumes were 113 ± 36 and 33 ± 12 cm(3), respectively. No differences were found between the AF‐free and AF‐recurrent groups regarding EAT volume. The EAT overlaps on LAPWI lines and LAPWI area were 1.2 ± 1.0 and 0.5 ± 0.9 cm(2) respectively. Although no difference was found between groups regarding the EAT overlap on LAPWI area, the AF‐free group had a significantly larger EAT overlap on LAPWI lines (1.4 ± 1.0 vs 0.6 ± 0.6 cm(2), P = .014). Multivariate analysis identified EAT overlap on LAPWI lines as an independent predictor of AF recurrence (hazard ratio: 0.399, 95% confidence interval: 0.178‐0.891, P = .025). Kaplan‐Meier analysis revealed that, during follow‐up, 92% of the large EAT overlap group (≥1.0 cm(2)) and 58% of the small EAT overlap group (<1.0 cm(2)) remained AF‐free (P = .008). CONCLUSIONS: EAT overlap on LAPWI lines is related to a high AF freedom rate. Direct radiofrequency application to EAT overlap may be necessary to suppress AF.