An angiographic study of intracoronary streptokinase versus intravenous tissue plasminogen activator after failed coronary thrombolysis with intravenous streptokinase

Abstract

Objective: The medical treatment of failed intravenous streptokinase in patients with acute transmural myocardial infarction using angiographic endpoints. Design: Prospective open angiographic comparison of intracoronary streptokinase with intravenous tissue plasminogen activator. Setting: Single center study in a tertiary institution. Subjects: Eighty-five patients with acute myocardial infarction within 4 hours after symptom onset. Treatment regimens: The subjects received 1.5 million U intravenous streptokinase. Coronary angiography within 48 hours (median 19 hours) showed infarct-related vessel patency in 65 patients (76%). In the catheterization laboratory the 20 patients (24%) with failed intravenous streptokinase received repeat thrombolysis immediately after angiography. The first 10 patients with failed intravenous streptokinase received intracoronary streptokinase at a dose of 4000 U/min in the occluded infarct-related artery for a maximum of 1 hour. The subsequent 10 pati ents received high-dose front-loaded intravenous tissue plasminogen activator (100 mg in 1 hour). Results: In none of the patients receiving repeat streptokinase was reperfusion obtained. In 6 of 10 (60%) of the patients receiving tissue plasminogen activator, reperfusion was seen within 60 minutes (p < 0.005 vs. intracoronary streptokinase). One patient (5%) died and two refused follow-up angiography. Seventeen (88%) patients underwent angiography 3 months later according to the protocol. Two patients showed a persistently reperfused infarct-related artery, three reoccluded, four spontaneously reperfused, and eight had a persistently occluded infarct-related artery. The left ventricular ejection fraction was slightly higher at 3 months, and there were no differences between the patients with open vessels (increase +7.7 +/- 5.8%) and those with persistently occluded vessels (increase +5.8 +/- 6.8%). Conclusions: Repeat thrombolysis after failed intravenous streptokinase ca n be achieved with front-loaded intravenous tissue plasminogen activator but not with intracoronary streptokinase. Although patient numbers are small and repeat thrombolysis was performed rather late, this study leads the way to affordable optimization of thrombolysis, which needs large-scale testing.