A study of the catabolism of fibrinogen after myocardial infarction.

The catabolism of fibrinogen was studied during the first week of acute myocardial infarction in twenty-three patients and in ten control patients. A trial was carried out using 125I-labelled fibrinogen. After myocardial infarction, the mean biological half-life of fibrinogen was 62.5 +/- 10.0 h and the mean plasma loss of fibrinogen per 24 hours was 34.1 +/- 6.9% of the intravascular fibrinogen pool. In the control group, respective values of 89.6 +/- 9.9 and 23.4 +/- 3.9% were obtained, which were in close agreement with published values for the normal catabolism of fibrinogen. The fractional catabolic rate of the intravascular fibrinogen pool was significantly increased in patients with myocardial infarction in contrast to the absolute plasma loss of fibrinogen which appeared to be the same as in subjects with normal plasma fibrinogen concentration. Possible explanations of the accelerated catabolism of fibrinogen after myocardial infarction are discussed.