Physiologically Assessed Coronary Collateral Flow and Intracoronary Growth Factor Concentrations in Patients With 1- to 3-Vessel Coronary Artery Disease

Abstract

Background —The purpose of this study was to test the hypothesis that there is a relation between collateral flow and intracoronary concentrations of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and that the combined concentrations of both growth factors and the extent of coronary artery disease (CAD) play a role as covariables in such an association. Methods and Results —In 76 patients undergoing balloon angioplasty, a collateral flow index (CFI, no units) was determined with sensor-tipped guidewires. Simultaneously, serum concentrations of bFGF and VEGF, obtained at the aortic root from the ostium of the collateralized coronary artery (n=76) and from the distal position of the occluded coronary artery (n=34), were determined. There was a direct correlation between CFI and distal VEGF ( r =0.33, P =0.05) but not bFGF concentrations. Focusing on the proximal sampling site, there was a direct correlation between CFI and both bFGF ( r =0.29, P =0.01) and VEGF concentrations ( r =0.44, P <0.0001). The sum of the concentrations of both growth factors was directly associated with CFI irrespective of the proximal ( r =0.51, P <0.0001) or distal sampling site ( r =0.34, P =0.048). There was a trend toward higher proximal VEGF concentrations in patients with higher numbers of coronary stenotic lesions ( r =0.25, P =0.03). Conclusions —In patients with CAD, there is an association between a directly measured index of collateral flow and intracoronary concentrations of bFGF and VEGF. This direct relation is dependent on the site of blood sampling within the coronary artery tree. The association is closest when the combined bFGF and VEGF concentrations are taken into account. In the case of VEGF, it is influenced by the degree of coronary atherosclerosis.