Left Atrial-Epicardial Adipose Tissue Is Associated with Worse Left Ventricular Strain In Atrial Fibrillation Patients

Yaacoub Chahine, MD – Internal Medicine Resident, University of Washington; hala Al yasiri, MD – Research Assistant, University of Washington; Nazem Akoum, MD – Section head of Cardiac Electrophysiology, University of Washington

Purpose: Atrial fibrillation (AF) is associated with abnormal left ventricular systolic and diastolic function. While left atrial epicardial adipose tissue (LA-EAT), a metabolically active visceral fat deposit has been associated with worse phasic left atrial strain, its effect on left ventricular (LV) function in AF patients is not well elucidated. We assessed the association between LA-EAT and LV function including global longitudinal strain (GLS) and global radial strain (GRS) using cardiac magnetic resonance in patients with AF.

Material and Methods: Patients were identified from the University of Washington Cardiac Arrhythmia Data Repository (CADRe). EAT volume was quantified using Dixon MRI sequences. The Cardiac Electro-Mechanic Research Group Application’s (CemrgApp) built-in tools were used to contour left atrial epicardial adipose tissue and total epicardial adipose tissue volume using Dixon sequences (panel A). Cardiac magnetic resonance cine images were used to extract GLS and GRS using image processing software (CVI42®) (panel B).

Results: 101 patients (average age 64 ±11 years; 72.3% male) were included. LA-EAT index was 18.22 ± 9.36 ml/m2. The median LV ejection fraction (LV-EF) was 57.6%±11.5. LV GLS and GRS were -14.86 ± 3.74% and 27.67 ± 10.22% repectively. LA-EAT was significantly correlated with LV GLS (R=0.261; p=0.008) and GRS (R=0.283; p= 0.004); but not with LV-EF (R=0.134; p=0.181) (panel C). Multivariate linear regression also showed an independent association between LV GLS and GRS along with LA-EAT after adjusting for body mass index, left atrial volume, and congestive heart failure.

Conclusions: LA-EAT is independently associated with worse LV global longitudinal strain and global radial strain. LA-EAT may negatively affect LV function in AF patients beyond the ejection fraction.