Numaguchi R, et al. - Whether perivascular adipose tissue (PVAT) surrounding the coronary artery (CA-PVAT), PVAT surrounding the internal thoracic artery (ITA-PVAT), and subcutaneous adipose tissue (SCAT) have distinct phenotypes was investigated. This study included 44 patients (men/women, 36:8; age, 67±13 years) with coronary artery (CA) disease who had elective CA bypass grafting. Fat pads were sampled from these patients. In CA-PVAT, researchers found a greater extent of fibrosis and increased gene expression levels of fibrosis-related molecules, vs those in SCAT and in ITA-PVAT. Furthermore, more pronounced metaflammation, a lower ratio of CD206-positive M2 to CD11c-positive M1 macrophages, a lower gene expression level of adiponectin, and higher gene expression levels of inflammatory cytokines and inflammasome- and endoplasmic reticulum stress–related molecules were seen in CA-PVAT vs in ITA-PVAT and SCAT. Most likely due to inherent differences in adipocytes, the phenotype of ITA-PVAT was found to be closer to that of SCAT than that of CA-PVAT. Metaflammation and consecutive adipose tissue remodeling was not seen in ITA-PVAT; this could contribute to the decreased atherosclerotic plaque burden in the ITA.