Changes in coagulation factors following acute myocardial infarction in man.

The whole blood clotting time, plasma fibrinogen and individual coagulation factors II, V, VII, VIII, IX, X, XI, and XII were serially measured in 14 patients over a 10-day period following acute myocardial infarction. A further six patients with similar symptoms but without evidence of myocardial infarction were also studied. The whole blood clotting time was significantly shorter within the first 24 h after infarction than on subsequent days. There were significant increases in the levels of fibrinogen and of factors VIII, IX, and XI and a significant decrease in factor XII in the patients who had sustained a myocardial infarction. The patients without myocardial infarction had no significant change in any of the coagulation factors measured.