Background: Epicardial adipose tissue (EAT) is a visceral adipose tissue (AT) surrounding
and infiltrating myocardium and coronary arteries. Increased EAT may represent a chronic inflammatory
injury and a link with coronary artery disease (CAD). Metalloproteinases (MMPs) are involved in expansion
Objective: To evaluate MMP-2 and -9 behaviour in EAT from CAD patients.
Methods: In EAT and subcutaneous AT (SAT) from patients undergoing coronary artery bypass graft
(CABG, n=26) or valve replacement (No CABG, n=18), MMP-2 and -9 activity and localization, inflammatory
cells and vascular endothelial growth factor (VEGF) levels were determined.
Results: In EAT from CABG, MMP-2 and -9 activity was increased compared with No CABG (p=0.041
and p=0.027, respectively) and compared with SAT (p=0.005 and p=0.048, respectively). In CABG patients
EAT showed higher infiltration of macrophages and T lymphocytes than SAT (p=0.01 and p=0.002,
respectively). In No CABG patients no sign of cellular retention was observed in EAT or SAT. Vascular
density was higher in EAT from CABG than No CABG (p=0.015) and it was directly correlated with
MMP-2 (p=0.006) and MMP-9 (p=0.02). VEGF levels in EAT were directly associated with MMP-2
Conclusion: In EAT from CABG patients the increase of MMP-2 and -9 activity and the presence of
inflammatory cells would be partially responsible for extracellular matrix (ECM) remodeling and major
vascular density necessary for EAT expansion. Improved knowledge of EAT behaviour may allow to
identify new therapeutic targets for the treatment of CAD.