Association of epicardial fat with cardiac structure and function and exercise capacity in heart failure with preserved ejection fraction: A systematic review and meta-analysis

Studies have reported the association of epicardial adipose tissue (EAT) with cardiac structure and function as well as exercise capacity in patients with heart failure with preserved ejection fraction (HFpEF), yielding inconsistent results. We aimed to conduct a meta-analysis of studies on the association of EAT with cardiac structure and function and exercise capacity in HFpEF patients. We searched studies examining the association of EAT quantified by echocardiography, computed tomography, or magnetic resonance imaging (MRI) with cardiac structure and function or exercise capacity in HFpEF patients through PubMed, Web of Science, and Scopus. In cases of significant heterogeneity (I2 > 50 %), data were pooled using a random-effects model; otherwise, a fixed-effects model was used. We identified five echocardiography studies (n = 825) and six MRI studies (n = 562), but found no computed tomography studies. In the echocardiography studies, EAT thickness correlated positively with left ventricular (LV) mass (Prandom < 0.01) and negatively with LV global longitudinal strain (Prandom < 0.01) and peak exercise oxygen uptake (Pfix < 0.001). In the MRI studies, EAT volume correlated positively with LV mass (Pfix < 0.01), left atrial volume (Pfix < 0.001), and the ratio of LV early diastolic mitral inflow to early diastolic mitral annular velocity (E/e’; Prandom < 0.01) and negatively with LV ejection fraction (Pfix < 0.01) and LV global longitudinal strain (Pfix < 0.001). Our meta-analysis indicates a potential association of increased EAT with altered cardiac structure and function and exercise intolerance in HFpEF patients. However, our meta-analysis included only two or three studies for each outcome and thus further studies are necessary to confirm our findings.