PO-02-088 CHANGES IN EPICARDIAL ADIPOSE TISSUE AND LEFT ATRIAL WALL SUBSTRATE AFTER ABLATION FOR ATRIAL FIBRILLATION

Abstract

Previous studies have shown that epicardial adipose tissue (EAT) contributes to the presence of atrial fibrillation (AF), possibly due to atrial fatty infiltration and/or the release of cytokines from the EAT. Conversely, it remains unclear whether sinus rhythm maintenance after catheter ablation (CA) provide favorable effects on EAT volume, EAT quality and left atrial (LA) fatty infiltration (EAT quality and LA fatty infiltration can be estimated from attenuation measured by CT) (figure). This study aimed to determine changes in EAT volume and quality, LA fatty infiltration, before and after CA. Total 20 patients (62± 10 years, 16 males, 4 persistent AF) who had undergone CA. The multidetector CT was performed within 1 week before and 1 year after ablation. The EAT volume was measured as defined by -50 to -200 Hounsfield units (HU). We also evaluated CT attenuation of EAT (around the whole heart and LA), and LA wall CT attenuation (in the LA roof and LA posterior). The CT attenuation of EAT was measured automatically on 3D workstation. The LA wall attenuation was measured at 3 sites per segment, the average of the 3 values was calculated for each site, and these average values were used for the analysis. All patients had no recurrence 1 year after CA. The EAT volume decreased significantly from the before ablation to after (whole EAT: 108±46 ml to 93±35 ml; P=0.022, LA-EAT: 30± 14 ml to 23±12 ml; P=0.002). There was no significant difference in the EAT attenuation between before and after ablation (whole EAT: -92±3 HU to -92±4 HU; P=0.94, LA-EAT: -90±5 HU to -90±4 HU; P=0.93). The LA wall attenuation did not change either (LA roof: 23±7 HU to 24±10 HU; P=0.35, LA posterior: 34±7 HU to 30±8 HU; P=0.35). EAT volume decreased after the maintenance of sinus rhythm, but CT attenuation of EAT and LA wall was unchanged over time, suggesting that EAT is a consequence of AF, but EAT quality and LA substrate persists despite sinus rhythm maintenance.