The extrinsic fibrinolytic system in survivors of myocardial infarction.

The extrinsic fibrinolytic system was assessed among 124 consecutive survivors of acute myocardial infarction below 70 years of age. In samples drawn 3 months after discharge from hospital, the PAI-1 levels were higher and the tPA activities were lower than among elderly healthy controls. In contrast, the AMI survivors had higher tPA antigen levels at rest and after venous occlusion, and higher tPA activities after venous occlusion. Among patients having PAI-1 levels greater than 10 IU/ml, there was a positive correlation between PAI-1 and serum triglycerides, and a negative correlation between PAI-1 and age; this group was also significantly younger than the subgroup having less than or equal to 10 IU/ml of PAI-1. There were thus multiple disturbances of the extrinsic fibrinolytic system among these patients. As cardiovascular risk factors, these disturbances appear to be relatively more important the younger the patients are.