Interpretation of elevated serum VEGF concentrations in patients with myocardial infarction

Serum has been considered an unsuitable medium for measurements of circulating vascular endothelial growth factor (VEGF) since platelets release significant quantities of VEGF during clotting. Nevertheless, the assessment of platelet-derived VEGF may be important in patients with acute coronary syndromes characterized by intraluminal thrombosis. The present study aimed at identifying the factors that impact on the interpretation of serum VEGF concentrations in patients with ST-elevation myocardial infarction (STEMI). VEGF was measured in 106 patients with STEMI and correlated with clinical and angiographic parameters. Serum VEGF levels were significantly higher in patients with STEMI than in healthy controls. Although the average number of platelets did not differ between the groups, the patients with STEMI, but not the controls, exhibited a significant correlation between serum VEGF levels and platelet counts. Stratification of patients according to different criteria revealed that VEGF concentrations were particularly elevated shortly (<3h) after the onset of chest pain in those patients who had occluding thrombi graded as large (3-4) on a TIMI scale. These data demonstrate that high levels of serum VEGF detected early in the course of STEMI may derive from activated platelets and may characterize patients with extensive intracoronary thrombosis.