Activation of Fibrinolysis by Physical Exercise in Healthy Individuals With Different Sporting Activities and in Patients After Myocardial Infarction

Abstract

Regular vigorous sporting activities are known to stimulate blood fibrinolytic capacity estimated by the venous occlution test, and have been reported to have a prophylactic effect against the development of coronary artery disease and myocardial infarction. In the present study, the influence of regular physical exercise on fibrinolysis was studied in healthy individuals and in patients after myocardial infarction taking part in a rehabilitation sports program. The activation of fibrinolysis after bicycle ergometry was investigated in 4 groups of subjects. Group A: 18 healthy male competitive athlets (23 ± 3.5 years of age, mean ± S.D.), Group B: 18 healthy male volunteers (25.7 ± 2.7 years) not engaged in any sporting activities, Group C: 17 healthy male volunteers (50.5 ± 7.7 years) regularly practicing sports, and Group D: 18 male patients after myocardial infarction (54.2 ± 7.9 years). Group A (13.9 ± 2.6 AU/ml, mean ± S.D.) and Group C (15.2 ± 2.9 AU/ml) revealed lower (p-4. 0.05) plasma plasminogen activator inhibitor capacities (PAI-cap) than Group B (18.5 ± 5.5 AU/ml) and Ml-patients (20.7 ± 5.5 AU/ml). All groups showed a significant increase in plasma tissue plasminogen activator (tPA) antigen levels during exercise (Group A: 8.4 ± 6.7 ng/ml; Group B: 7.1 ± 6.2 ng/ml; Group C: 4.9 ± 3.0 ng/ml; and Group D: 3.0 ± 2.9 nl). After exercise significantly higher tPA activities were measured in persons with low PAI-cap at rest (Group A: 5.5 ± 6.4 IU/ml; Group C: 2.9 ± 3.3 IU/ml), whereas Group B (1.1 ± 3.0 IU/ml) and Group D (0.2 ± 0.7 IU/ml) showed only weak activities. Fibrinogen and fibrin split products (D-dimer) levels did not change during exercise testing. The present study indicates that 1. regular vigorous physical exercise enhances blood fibrinolytic activity by reducing blood PAI-cap in healthy individuals, 2. rehabilitation sport is not capable of reducing blood PAI-cap in Ml-patients, and 3. the increased fibrinolytic capacity after physical exercise does not induce systemic fibrinolytic effects.