title: Intracoronary artery thrombus formation in unstable angina: a clinical, biochemical and angiographic correlation.
abstract: OBJECTIVE
  We examined the relation between the level of urinary fibrinopeptide A and the presence of angiographic intracoronary thrombus in patients with unstable angina to determine whether this marker predicts active thrombus formation.
  
  
  BACKGROUND
  Although it is known that thrombus plays a role in acute ischemic syndromes, a noninvasive method to predict its presence in individual patients with unstable angina has not been determined. Fibrinopeptide A is a polypeptide cleaved from fibrinogen by thrombin and thus is a sensitive marker of thrombin activity and fibrin generation.
  
  
  METHODS
  Angiographic thrombus, graded 0 to 4, and the presence of ST segment depression or T wave inversions, or both, on the electrocardiogram (ECG) were related to fibrinopeptide A levels in 24 patients with rest angina of new onset, 18 with crescendo angina, 19 with stable angina and 9 with chest pain but without coronary artery disease. All patients had chest pain within the 24 h of sample acquisition.
  
  
  RESULTS
  The angiographic incidence of thrombus was significantly higher in patients with new onset of rest angina (67%, p < 0.001) and crescendo angina (50%, p < 0.001) as were fibrinopeptide A levels (p = 0.002). Fibrinopeptide A levels correlated significantly (p < 0.001) with the presence of a filling defect (grade 4 intracoronary thrombus) or contrast staining (grade 3). All patients with fibrinopeptide A > or = 8 ng/mg creatinine showed grade 3 to 4 thrombus and 15 of 16 patients with levels > or = 6.0 ng/mg creatinine exhibited angiographic evidence of thrombus (13 with grades 3 to 4). Patients with reversible ST changes on the ECG had significantly higher levels of fibrinopeptide A (p < 0.001), and ST changes correlated significantly with the presence of angiographic thrombus (p < 0.001). Nonetheless, a significant minority of patients with unstable angina had neither angiographic nor biochemical evidence of thrombus.
  
  
  CONCLUSIONS
  Elevated fibrinopeptide A levels in unstable angina reflected active intracoronary thrombus formation and were present in patients with angina of new onset as well as crescendo angina. Reversible ST changes are accompanied by thrombin activity and angiographic thrombus formation. However, a sizable percentage of patients with unstable angina had no evidence of thrombus and these patients may have had transient platelet aggregation without fibrin thrombus formation.
authors.affiliation: Krannert Institute of Cardiology, Department of Medicine, Indianapolis, Indiana 46202-4800.
authors.forename: R L
authors.initials: RL
authors.lastname: Wilensky
authors.forename: P D
authors.initials: PD
authors.lastname: Bourdillon
authors.forename: V A
authors.initials: VA
authors.lastname: Vix
authors.forename: J A
authors.initials: JA
authors.lastname: Zeller
mesh_terms: D000789:Angina, Unstable / Q000150:complications*; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D005344:Fibrinopeptide A / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012044:Regression Analysis
chemical_list: D005344:Fibrinopeptide A