Physiologically assessed coronary collateral flow and intracoronary growthfactor concentrations in patients with 1-to 3-vessel coronary artery disease

Background-The purpose of this study was to test the hypothesis that there is a relation between collateral flow and intracoronary concentrations of b asic 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 collat eral flow index (CFI, no units) was determined with sensor-tipped guidewire s. Simultaneously, serum concentrations of bFGF and VEGF, obtained at the a ortic root from the ostium of the collateralized coronary artery (n = 76) a nd 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 samp ling 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 th e concentrations of both growth factors was directly associated with CFI ir respective 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 concent rations 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 directl y measured index of collateral flow and intracoronary concentrations of bFG F and VEGF. This direct relation is dependent on the site of blood sampling within the coronary artery tree. The association is closest when the combi ned bFGF and VEGF concentrations are taken into account. In the case of VEG F, it is influenced by the degree of coronary atherosclerosis.