Associations of the left atrial epicardial fat thickness with the thrombosis prevalence and left atrial appendage flow velocity in patients with persistent non-valvular atrial fibrillation

Abstract

Aim. To study the associations of the left atrial epicardial fat (LAEF) thickness with the thrombosis prevalence and left atrial appendage (LAA) flow velocity in patients with persistent non-valvular atrial fibrillation (AF).Material and methods. Transesophageal echocardiography in 475 patients with persistent non-valvular AF (men 58,9%, age 64,0 (58,3-70,0) years) assessed LAA flow velocity, interatrial septum and left lateral ridge thickness. Their average thickness was used to estimate the LAEF volume.Results. LAA thrombus was detected in 42 (8,8%) patients. LAA flow velocity without thrombus was 32,0 (26,0-39,0) cm/s, with thrombus — 20,0 (14,0-25,8) cm/s (p<0,0001). Depending on the LAEF thickness, patients were divided into 3 tertile groups: group 1 (n=168) — 5,6-7,4 mm, group 2 (n=154) — 7,45-8,2 mm, group 3 (n=153) — 8,25-10,9 mm. In group 1, no thrombus was detected, in group 2, thrombus was detected in 2 (1,3%) patients, in group 3 — in 40 (26,0%) patients (p<0,0001). In the absence of LAA thrombus, flow velocity in the selected groups did not differ (32,0 (26,0-39,0) cm/s, 31,0 (26,0-7,8) cm/s and 31,5 (25,0-40,0) cm/s, (p=0,9514)).Conclusion. EFL thickness, calculated as the average of interatrial septum and left lateral ridge thickness, can be used to study the relationship between epicardial obesity and LAA thrombosis in patients with AF. In patients with persistent non-valvular AF with a LAEF thickness >8,2 mm, LAA thrombosis occurs more than 40 times more often than in patients with a lower LAEF thickness. The influence of LAEF thickness on LAA flow velocity was not revealed in the pre­sent study.