Aims: Accumulation of epicardial adipose tissue (EAT) is associated with severity and progression of coronary artery disease
(CAD). The aim of this study was to compare EAT fibrosis, inflammation, Hypoxia-inducible factor 1-alpha (HIF1-α) and caveolin-1
(CAV-1) between subjects with and without CAD.
Methods and Results: Body mass index (BMI), waist circumference (WC), glucose, insulin, homeostasis model assessment index,
serum leptin and adiponectin were evaluated in EAT of patients with and without CAD undergoing elective surgery. Biopsies were
collected from EAT. Immunohistochemistry for macrophages CD68, CD11c, CD163, HIF1-α and CAV-1 was performed and Masson
Trichrome staining to define the degree of fibrosis. A total of 22 male patients (age range from 51-80 years), were studied: 12 CAD
and 10 non-CAD undergoing elective surgery.
Fibrosis (1.29 ± 0.71 vs 0.54 ± 0.40, p<0.01), HIF1-α (2.39 ± 1.64 vs 1.01 ± 0.94, p<0.05), number of total CD68 (74.25 ± 49.39
vs 37.33 ± 18.28, p<0.05), CD163 (57.75 ± 38.23 vs 31.11 ± 18.54, p<0.05) and CD11c (6.67 ± 4.73 vs 2.05 ± 1.13, p<0.01) were
higher in CAD than in non-CAD patients, whilst serum adiponectin (8.25 ± 7.52 vs 15.06 ± 11.11, p<0.05), and CAV-1 (0.0790
± 0.0268 vs 0.0987 ± 0.0164, p<0.05) significantly lower. In 4 patients with CAD, but in none in those without, macrophages
aggregated in crown like structure were found. Fibrosis correlated with HIF1-α (r= 0.644, p < 0.01) and M1 pro-inflammatory
CD11c (+) macrophages (r=0.601, p<0.01); HIF1-α with total, M1 pro-inflammatory CD11c (+) and M2 anti-inflammatory CD163
(+) macrophages (r=0.5313, p<0.05; r=0.6385, p<0.01; r=0.6730, p<0.001, respectively); Caveolin-1 positively correlated with
serum adiponectin (r=0.4347, p<0.05).
Conclusions: CAD patients displays a dysfunctional EAT characterized by greater inflammation, fibrosis, HIF1-α and lower CAV. Our
results seem to suggest that adiponectin may decline CAD risk even by determining an increase of CAV-1.
Abbreviations: BMI, Body Mass Index; WC, Waist Circumference; HOMA, Homeostasis Model Assessment; CAV-1, caveolin 1; ADIP
DIAMETER, diameter of adipocytes; HIF1-α, number of adipocytes nuclei positive for Hypoxia-inducible factor 1-alpha M CD68,
Total Macrophages; M2 CD163, Anti-inflammatory Macrophages; M1 CD11c, Proinflammatory Macrophages *p<0.05, **p<0.01,