Altered Levels of Fatty Acids and Inflammatory and Metabolic Mediators in Epicardial Adipose Tissue in Patients With Systolic Heart Failure

Abstract Background Adipose tissue has endocrine properties, secreting a wide range of mediators into the circulation, including factors involved in cardiovascular disease. However, little is known about the potential role of adipose tissue in heart failure (HF), and the aim of this study was to investigate epicardial (EAT) and subcutaneous (SAT) adipose tissue in HF patients. Methods and Results Thirty patients with systolic HF and 30 patients with normal systolic function undergoing thoracic surgery were included in the study. Plasma was sampled and examined with the use of enzyme-linked immunosorbent assays, whereas SAT and EAT biopsies were collected and examined by means of reverse-transcription polymerase chain reaction and gas chromatography. Significantly higher expressions of mRNA encoding interleukin-6, adrenomedullin, peroxisome proliferator–activated receptor α, and fatty acid (FA)–binding protein 3, as well as higher levels of monounsaturated FA and palmitoleic acid, were seen in the EAT of HF patients, whereas the levels of docosahexaenoic acid were lower. Palmitoleic acid levels in EAT were correlated with 2 parameters of cardiac remodeling: increasing left ventricular end-diastolic diameter and N-terminal pro–B-type natriuretic peptide. Conclusions Our results demonstrate adipose tissue depot–specific alterations of synthesis of FA and inflammatory and metabolic mediators in systolic HF patients. EAT may be a source of increased circulatory and myocardial levels of these mediators through endocrine actions.