Inhibitors of the hemostasis and related systems in patients with acute myocardial infarction or unstable angina pectoris

Abstract

Background : alterations of the hemostatic and fibrinolytic systems are known in patients with acute coronary syndromes. Objective: to investigate the meaning of several inhibitors of these systems in patients with acute myocardial infarction (n = 20) and unstable angina pectoris (n = 21). Methods: repeated venous blood sampling was performed during the first 10 days after admission. Plasma inhibitors were measured using chromogenic substrate tests. Data were compared with controls (n = 25). Results: the C 1 -esterase inhibitor did not show a significant difference to the controls, but in patients with unstable angina pectoris a slight intraindividual increase during the follow-up was observed. α 2 -macroglobulin in contrast was transiently reduced in comparison with the controls ( p < 0.05) in patients with unstable angina pectoris, whereas no significant alterations were found in patients with acute myocardial infarction. α 1 -antitrypsin increased in both groups significantly during the observation period indicating an acute phase reaction. Antithrombin III was slightly decreased in patients with acute coronary syndromes during the 10 day follow-up. No significant alterations were found in α 2 -antiplasmin and protein C levels. Conclusion: our results indicate that besides the known alterations of the plasmiogen activator inhibitor in the fibrinolytic system the other inhibitor systems are only slightly involved. The borderline alterations indicate consumption of some of the inhibitors due to the known activation of thrombin generation or the kallikrein-kinin system, but do not indicate that an inhibitor deficiency is a reason for the activation of the coagulation in acute coronary syndromes.