Effect of the epicardial fat volume on the outcomes after a left atrial posterior wall isolation in addition to pulmonary vein isolation in patients with persistent atrial fibrillation

Background While the effect of a circumferential pulmonary vein isolation (CPVI) alone is unsatisfactory, that of an additional electrical posterior wall box isolation (POBI) is controversial in persistent atrial fibrillation (PeAF) patients. Increased epicardial adipose tissue (EAT) is associated with higher recurrence rates after AF catheter ablation (AFCA). Purpose We investigated the possible effects of a POBI on rhythm outcomes with varying EAT volumes. Methods We included 1,187 patients with PeAF undergoing a de novo AFCA (79.6% male, median age 60 years) into two groups including those receiving a CPVI alone (n=687) and those an additional POBI (n=500). The rhythm outcomes at two years post-AFCA were compared in subgroups stratified by the total EAT volume using propensity overlap weighting. Results A reduced total EAT volume was linearly associated with more favorable rhythm outcomes for an additional POBI treatment than for a CPVI alone (P for interaction=0.002). Among the patients with smaller EAT volumes (≤116.23 ml, the median value, n=594), an additional POBI was associated with a reduced AF recurrence risk as compared to a CPVI only (weighted hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.56–0.99; weighted log-rank P=0.039). In contrast, among the remaining 593 patients with greater EAT volumes (>116.2 3mL), there was no difference in the AF recurrence risk between an additional POBI and CPVI alone (weighted HR 1.13, 95% CI 0.84–1.52; weighted log-rank P=0.410). Among 185 patients with a repeat ablation, the POBI reconnection rate tended to be higher in the large EAT group (75.0%) than small EAT group (55.4%, P=0.060). Conclusion While PeAF patients with a smaller EAT volume averted AF recurrence by an additional POBI after the CPVI, no benefit of the POBI was observed in those with a greater EAT volume. The EAT volume might identify AF patients likely to benefit from linear ablation in addition to the CPVI. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Ministry of Science, ICT & Future Planning (MSIP)Korean Ministry of Health and Welfare