Increase in thrombin generation after coronary thrombolysis with rt-PA or streptokinase with simultaneous heparin versus heparin alone.

This study compares the extent of inhibition of thrombin generation and activity achieved in patients with acute myocardial infarction receiving fibrinolytic treatment (streptokinase SK, or rt-PA) and concomitant intravenous heparin treatment adjusted to the patients' weight with that achieved with the same heparin regimen but without fibrinolytic therapy. The study involved 90 patients, grouped according to their treatment: SK+heparin; rt-PA+heparin, and heparin without thrombolytic agents. Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), fibrinopeptide A (FPA) and activated partial thromboplastin time were measured. Patients treated with SK+heparin or rt-PA+heparin and higher F1+2 plasma levels than the patients treated with heparin alone at 12, 48 and 72 h in the case of SK+heparin, and at 12, 24, 48 and 72 h in that of rt-PA+heparin. Compared to baseline, the plasma levels of FPA were decreased in the three treatment groups at 24-48 h. There were no significant changes in TAT and FPA plasma levels among the three treatment groups at the different times. After thrombolytic therapy with both SK and rt-PA, there was an increase in thrombin generation, although high-dose intravenous heparin inhibited the different increases in thrombin associated with the thrombolytic agents to the same extent.