Abstract 4225: Periadventitial Adipose Tissue Inflammation Assessed By 64-slice Computed Tomography Is Associated With Coronary Artery Atherosclerosis

Abstract

Background It has become increasingly evident that adipose tissue is a multifunctional organ that produces and secretes various paracrine and endocrine factors. Periadventitial cardiac adipose tissue (PCAT), which exists closely around coronary arteries, is now recognized as a rich source of a number of bioactive molecules. There have been some reports that highlight local chronic inflammation of PCAT as a potential contributing factor to the pathogenesis of coronary artery disease (CAD) and adipose tissue with inflammation is known to have high density in computed tomography (CT). We assessed CT density of adipose tissues to evaluate the inflammatory activity and investigated the association between PCAT inflammation and CAD. Methods and results We assessed the CT density of periadventitial adipose tissues in consecutive 69 patients suspected of CAD ( 51% men, 65 ± 11 years) using 64-slice CT. By using the image scanned for coronary CT angiography, adipose tissue and presence of CAD (>75% organic stenosis) were confirmed in the same scan. We measured CT density of PCAT around the proximal right coronary artery (Coronary-PCAT), pericardial fat apart from coronary arteries (between ascending and descending aorta as the control site; Cont-PCAT), and thoracic subcutaneous fat. In each of these sites, the CT density measurements in two or more regions of interest were randomly performed and the mean value was recorded. The mean of CT density was −81 ± 11 Hounsfield Unit (HU) in Coronary-PCAT, −99±11HU in Cont-PCAT, −103±7HU in the subcutaneous fat, which were significantly different values (p < 0.01). The difference of CT density between Coronary-PCAT and the Cont-PCAT was significantly greater in patients with CAD (n = 30) than those without CAD (n=39) (22±16 versus 16±10 HU, p < 0.05) but the difference between Cont-PCAT and subcutaneous fat was not related to the presence of CAD (6 ± 12 versus 3 ± 14 HU, p = 0.22). Conclusions Coronary-PCAT had significantly higher CT density than the Cont-PCAT and subcutaneous fat. The difference of CT density between Coronary-PCAT and Cont-PCAT was significantly greater in patients with CAD than non-CAD patients. The inflammatory actively of local PCAT rather than whole pericardial fat may implicate in the development of CAD.