Effect of Epicardial Adipose Tissue on Cardiac Function and Exercise Hemodynamics in Patients With Heart Failure With Preserved Ejection Fraction

Background Obesity is a significant risk factor for developing Heart Failure with Preserved Ejection Fraction (HFpEF). Epicardial adipose tissue (EAT) in particular, has been implicated in the pathophysiology of HFpEF, both from metabolic and mechanical effects. Previous studies have linked greater EAT to higher cardiac filling pressures and adverse inter-ventricular interactions at rest and during (supine) exercise. However, inter-ventricular interactions are exaggerated in the supine position, which may magnify the effects of EAT on cardiac function and hemodynamics. Therefore, we investigated the associations between EAT quantified by MRI, subdivided by left (LV) or right ventricle (RV), and cardiac function and resting and exercising hemodynamics assessed in patients with obesity and HFpEF in the upright position. Methods We studied 32 patients with HFpEF (19 women; BMI, 37±6kg/m 2 ; age, 69±6years). Total and visceral fat were assessed with dual-energy x-ray absorptiometry. MRI was used to quantify global longitudinal strain (GLS) and total EAT volume across short axis slices. EAT volume was partitioned by underlying location – LV or RV. Exercise was performed on a semi recumbent cycle ergometer and filling pressures (right heart catheterization), oxygen uptake (V̇O 2 ), cardiac output (Q̇c, direct Fick) were assessed at rest, 20 Watts, and peak exercise (87±35 Watts); diastolic function (echocardiography) was assessed at rest and during 20 Watts. Results EAT moderately correlated with visceral adiposity (r=0.57, P