Do plasma biomarkers of coagulation and fibrinolysis differ between patients who have experienced an acute myocardial infarction versus stable exertional angina?

Background Circulating concentrations of proteins associated with coagulation and fibrinolysis may differ between individuals with coronary artery disease (CAD) who develop an acute myocardial infarction (AMI) rather than stable exertional angina. Methods We compared plasma concentrations of fibrinogen, d-dimer, tissue-type plasminogen activator, and plasminogen activator inhibitor-1 (PAI-1) between patients whose first clinical manifestation of CAD was an AMI (n = 198) rather than stable exertional angina (n = 199). We also compared plasma concentrations of these proteins between patients with symptomatic CAD (either AMI or stable angina; n = 397) and healthy, control subjects (n = 197) to confirm the sensitivity of these assays to detect epidemiologic associations. Results At a median of 15 weeks after presentation, patients with AMI had slightly higher d-dimer concentrations than patients with stable angina (P = .057), but were not significantly different in other markers. By contrast, fibrinogen, d-dimer, and tissue-type plasminogen activator were significantly higher (P < .001) and PAI-1 lower in patients with CAD than in healthy control subjects. After statistical adjustment for clinical covariates, cardiac risk factors, medications, and other confounders, fibrinogen, d-dimer, and PAI-1 remained significantly associated with CAD. Conclusion Selected plasma markers of coagulation and fibrinolysis did not distinguish patients presenting with AMI from those with stable exertional angina.