Coronary thrombolysis with human single-chain, urokinase-type plasminogen activator (pro-urokinase) in patients with acute myocardial infarction.

Single-chain, urokinase-type plasminogen activator (pro-urokinase), isolated from the conditioned medium of a human renal adenocarcinoma cell line, was administered to six patients with evolving myocardial infarction of less than 5 hours' duration and angiographically confirmed total occlusion of the infarct-related coronary artery. The agent was infused intravenously at a rate of 40 mg over 60 minutes immediately followed in three patients by intracoronary infusion of 20 mg over 30 minutes. In four of the six patients complete reperfusion was obtained during intravenous administration and in one patient after 20 minutes of intracoronary infusion. One patient did not respond. The infusion caused significant changes in the fibrinogen level and generation of fibrinogen breakdown products in only one patient. Single-chain, urokinase-type plasminogen activator can induce clot-selective coronary thrombolysis in patients with acute myocardial infarction.