Summary
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.
Keywords
Ristocetin cofactor activity of vWF - vWF: Ag - FVIII: C - Myocardial infarction -
Unstable angina - Kinetic study
