Heart Fat Infiltration In Subjects With and Without Coronary Artery Disease

Context: Fat may accumulate around the heart in epicardial adipose tissue or inside the heart as lipid droplets (LDs). Objective: To compare myocardial steatosis between subjects with and without coronary artery disease (CAD and non-CAD) and to identify which cells contain LDs. Design: Body mass index, waist circumference, glucose, insulin, homeostasis model assessment index, leptin, adiponectin, and high-sensitivity C-reactive protein were evaluated in CAD and non-CAD subjects. Biopsies were collected from right atrial myocardium. Immunohistochemistry for perilipin (PLIN) 1 and 2 was used to characterize LDs and their localization in adipocytes or myocardial cells, respectively. Cardiomyocytes apoptosis and hypoxia inducible factor 1 alpha were obtained in a subgroup of subjects. Setting: The study took place in a hospital. Patients: Male subjects consecutively undergoing elective cardiac surgery either for coronary bypass grafting (CAD, n = 23) or for valve replacement (non-CAD, n = 18). Main Outcomes and Measures: The study was designed to compare myocardial steatosis between subjects with and without coronary artery disease. Results: PLIN1 and PLIN2 resulted significantly higher in CAD than in non-CAD subjects, as did apoptosis. PLIN1 was positively associated with circulating leptin, high-sensitivity C-reactive protein, and apoptosis, and negatively with adiponectin. PLIN2 was positively associated with body mass index, waist circumference, and leptin and negatively with adiponectin. After taking into account the absence/presence of hypertension, diabetes, and CAD/non-CAD, adiponectin was negatively associated with PLIN1 (r(2) = 0.532); waist circumference and adiponectin were associated with PLIN2 (r(2) = 0.399). Conclusions: Myocardial steatosis is greater in CAD than non-CAD subjects, depending on both metabolically active adipocytes interspersed among cardiomyocytes and higher fat deposition inside cardiomyocytes; serum adiponectin and waist circumference are independent predictors of myocardial steatosis.