Effects of Epicardial Adipose Tissue on Cardiac Function and Exercise Hemodynamics in Patients with HFpEF

Obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF). Epicardial adipose tissue (EAT), a fat depot between the epicardium and pericardium, has been implicated in HFpEF pathophysiology due to metabolic and mechanical effects. Prior research suggested that increased EAT is associated with higher cardiac filling pressures and adverse interventricular interactions, particularly in a supine position where these effects may be exaggerated. In addition, EAT is one of many fat depots, including subcutaneous and visceral fat, that may impact HFpEF exercise hemodynamics. This study aimed to examine EAT's association, quantified by MRI and differentiated by left and right ventricles, with cardiac function and hemodynamics during upright exercise in patients with obesity and HFpEF.

Presented at #AHA24, our research involved 32 patients with HFpEF and obesity (mean BMI = 37 kg/m2). We measured total and visceral fat using dual-energy X-ray absorptiometry (DEXA). MRI was used for precise EAT volumetric quantification (across short-axis slices) and to assess systolic function through global longitudinal strain. Participants underwent exercise testing on a seated upright cycle ergometer, and we evaluated filling pressures (via right heart catheterization), oxygen uptake, cardiac output (direct Fick), and diastolic function (echocardiography).

Our results demonstrated a moderate association between EAT and visceral adiposity but no significant associations with total body fat, diastolic function, cardiac filling pressures, or exercise capacity. Although EAT is a recognized risk factor for HFpEF, it does not appear to further affect cardiac function in patients with obesity and HFpEF. Instead, EAT might represent an additional visceral ectopic fat depot indicative of poor cardiometabolic health in this population.