Serum basic fibroblast growth factor levels in exercise-induced myocardial ischemia more likely a marker of endothelial dysfunction than a marker of ischemia?

: Increased levels and activity of fibroblast growth factor (FGF) have been documented in a variety of diseases, including ischemia. Both acute coronary syndromes and exercise are situations that stimulate FGF release. Since experimental studies have demonstrated that FGFs are involved in myocardial preconditioning, it has been suggested that cardiac and circulating FGFs may play a cardioprotective role in ischemic diseases. However, the profile of basic FGF (bFGF) release during transient myocardial ischemia remains uncertain. We sought to determine whether circulating bFGF might be changed in patients with demonstrated coronary artery disease and evidence of ischemia in exercise scintigraphy (Isch +; n = 21). Serum from 22 age-matched patients with no coronary artery disease and no isotopic ischemia (Isch-) were used as controls. Three blood samples were obtained to determine bFGF at different times: baseline (bFGF-A); maximal exercise (bFGF-B), and isotopic redistribution (bFGF-C). An enzyme-linked immunoassay specific for bFGF was used (limit of detection, 1.0 pg/ml). Circulating bFGF was increased at maximal exercise in both Isch + and control patients. However, serum levels of bFGF were elevated up to more than two-fold in Isch-patients compared to Isch+ patients (8.67 +/- 2.10 pg/ml in Isch+ vs 17.83 +/- 2.97 pg/ml in Isch- patients; p<0.01). According to previous data, these findings suggest that bFGF serum levels could be considered more likely a marker of endothelial dysfunction occurring in patients with coronary artery disease, rather than a marker of acute ischemia. This situation could be different in the clinical setting of chronic myocardial ischemia.