The blood coagulation system is frequently activated in the acute phase of
unstable angina, but it is unknown whether the augmented function of the
hemostatic mechanism may serve as a marker of increased risk for an early unfavorable outcome.
METHODS AND RESULTS: Plasma concentrations and 24-hour urinary excretion of
fibrinopeptide A were prospectively determined in 150 patients with
unstable angina. All patients underwent 24-hour Holter monitoring, during which time urine was collected; at the end of this period, a blood sample was taken and coronary arteriography was performed. The patients were followed up for the occurrence of
cardiac events (death and
myocardial infarction) until they underwent coronary revascularization or until they were discharged from the hospital.
Fibrinopeptide A plasma levels and 24-hour urinary excretion were found to be abnormally elevated in 50% and 45% of the study population, respectively. During hospitalization, 11 patients developed
myocardial infarction and 2 patients died. Kaplan-Meier analysis demonstrated a significantly higher probability of developing
cardiac events in patients with abnormal rather than normal plasma levels of
fibrinopeptide A (P<.01), whereas no difference in outcome was observed between patients with normal and those with abnormal 24-hour urinary excretion. Cox regression analysis showed that the only variables independently related to an early unfavorable outcome were the presence of persistent
ischemia during 24-hour Holter monitoring (P<.0001), the presence of intracoronary
thrombosis at angiography (P=.016), and abnormal
fibrinopeptide A plasma levels (P=.038).
CONCLUSIONS: