Systemic and intracardiac vascular endothelial growth factor and angiopoietin-1 and -2 levels in coronary artery disease: Effects of angioplasty

Background. Vascular growth factors are involved in the pathophysiology of human atherosclerotic vascular disease and plaque destabilization. We hypothesized that in stable patients with coronary artery disease (CAD), plasma levels of vascular endothelial growth factor (VEGF) and angiopoietins 1 and 2 (as indices of angiogenesis) would be no higher in coronary sinus blood when compared to the aortic root, coronary ostium, and peripheral femoral vein. Secondly, we hypothesized that percutaneous coronary intervention (PCI; angioplasty +/- stenting) would increase intracardiac levels of these indices, perhaps by destabilizing coronary plaques. Methods. Patients undergoing elective diagnostic coronary angiography (n=70; mean age 58.8 +/- 11.2 years) of which 37 proceeded to PCI were recruited. Blood samples were obtained from the aortic root, coronary ostium, coronary sinus, and femoral vein. Plasma VEGF, angiopoietin-1 and angiopoietin-2 levels were measured by immunoassays. Results. There were no significant differences in VEGF, angiopoietin-1 and angiopoietin-2 levels when aortic root, coronary ostium, coronary sinus, and femoral vein samples were compared (P=not significant (NS)). In patients undergoing PCI, peripheral angiopoietin-2 levels were increased significantly post PCI (P = 0.01). There was also a difference in intracardiac gradient (that is, aortic root-coronary sinus difference) in angiopoietin-1 (P = 0.02) following PCI. No significant changes in VEGF with PCI were noted. Conclusion. There were no differences in indices of angiogenesis when aortic root, coronary ostium, coronary sinus, and femoral vein levels of VEGF and angiopoietins are compared, suggesting that peripheral blood measurements of these indices are comparable to intracardiac levels. Although no immediate effects were observed in soluble VEGF levels, PCI affected intracardiac angiopoietin-1 with a systemic release of angiopoietin-2. Further investigations are necessary to determine the relative systemic and intracardiac effects of the angiopoietins in vascular remodelling post PCI.