THROMBIN ACTIVITY AND EARLY OUTCOME IN UNSTABLE ANGINA-PECTORIS

Background The blood coagulation system is frequently activated in the acute phase of unstable angina, but it is unknown whether the augment ed function of the hemostatic mechanism may serve as a marker of incre ased 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 pa tients underwent 24-hour Holter monitoring, during which time urine wa s collected at the end of this period, a blood sample was taken and co ronary arteriography was performed. The patients were followed up for the occurrence of cardiac events (death and myocardial infarction) unt il they underwent coronary revascularization or until they were discha rged from the hospital. Fibrinopeptide A plasma levels and 24-hour uri nary excretion were found to be abnormally elevated in 50% and 45% of the study population, respectively. During hospitalization, 11 patient s developed myocardial infarction and 2 patients died. Kaplan-Meier an alysis demonstrated a significantly higher probability of developing c ardiac events in patients with abnormal rather than normal plasma leve ls of fibrinopeptide A (P<.01), whereas no difference in outcome was o bserved between patients with normal and those with abnormal 24-hour u rinary excretion. Cox regression analysis showed that the only variabl es independently related to an early unfavorable outcome were the pres ence of persistent ischemia during 24-hour Holter monitoring (P<.0001) , the presence of intracoronary thrombosis at angiography (P=.016), an d abnormal fibrinopeptide A plasma levels (P=.038). Conclusions Patien ts with unstable angina pectoris and abnormal fibrinopeptide 4 plasma levels are at increased risk for an early unfavorable outcome.