An impaired fibrinolytic function, as evidenced by increased plasma concentrations of PAI-1, tPA antigen and tPA/PAI-1 complex, or a decreased capacity to release active tPA on exercise, is more common in individuals suffering from myocardial infarction. These factors, especially the tPA/PA-1 complex, also predict myocardial infarction in patients with manifest coronary heart disease, such as angina pectoris or a previous myocardial infarction. There is a highly statistically significant correlation between tPA/PAI-1 complex and both PAI-1 and tPA antigen. It is important to test these factors in prospective studies on healthy individuals.