Validity of epicardial fat volume as biomarker of coronary artery disease in symptomatic individuals: Results from the ALTER-BIO registry

Background: To determine if an increased epicardial fat volume (EFV) is associated with coronary artery disease (CAD) in individuals with symptoms of cardiovascular (CV) disease. Methods: Coronary Computed Tomographic Angiography (CCTA), demographic and clinical variables of 1344 individuals were retrieved: semi-automated measurements for EFV and coronary artery calcifications (CAC) were obtained. Individuals were grouped into three categories according to the presence of CAD, resulting in absent (CAD0), non-obstructive (CAD1) or obstructive (CAD2) disease-groups. Relation of EFV with CAD was assessed with two approaches: 1) presence of any CAD; 2) each individual CAD category. Results: Median EFV was 90.52 ml (range 11.27–442.21 ml); median CAC was 56.5 (range 0–10,144); 848 individuals (63.1%) were categorized as CAD0, 326 (24.3%) as CAD1, 170 (12.6%) as CAD2. EFV was lower in subjects without CAC (EFVmedian = 66.5 ml), as compared to those with CAC 0.1–100 (EFVmedian = 91.47), CAC 100.1–400 (EFVmedian = 97.46) and CAC >400 (EFVmedian = 109.48) (p < 0.001). EFV was lower in CAD0 (EFVmedian = 87.21 ml), as compared to CAD1 (EFVmedian = 93.89 ml) and CAD2 (EFVmedian = 102.98 ml) individuals (p < 0.001). A logistic regression model built by including demographic and clinical variables showed inconsistent predictive value of EFV for either CAD1 or CAD2 (p > 0.05). Conclusions: In the setting of symptomatic individuals, an increased amount of epicardial fat was associated with larger amount of coronary artery calcifications and was observed in individuals with obstructive CAD, however without predictive value to confidently determine CAD presence and severity.