The von Willebrand Factor in Myocardial Infarction and Unstable Angina: A Kinetic Study

Abstract

Recent studies have demonstrated elevations of von Willebrand Factor following acute myocardial infarction (AMI). In order to determine if this parameter may serve as a marker for AMI, we tested the blood levels of vWF and Factor VIII:C in 28 patients with AMI, 9 patients with unstable angina, 7 patients with atypical chest pain, and 25 healthy volunteers. The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. In patients with AMI, the mean level of this activity was 175% on the first day following infarction, rose to a peak of 270% on the fifth and sixth days, and was still significantly greater than normal in all patients on the 14th day. The vWF:Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. FVIII:C was not significantly changed. No significant elevation of vWF was observed in patients with unstable angina. The ristocetin cofactor activity of vWF and vWF:Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels.