Thrombolytic therapy for acute transmural myocardial infarction. Intracoronary versus intravenous.

The application of coronary angiography in coordination with streptokinase administration directly into the occluded coronary artery has served to focus attention on the clinical potential of such therapy. About 75 percent of patients with acute transmural myocardial infarction have been shown to have reperfusion after intracoronary administration of streptokinase. However, the data do not prove that the beneficial effect required regional perfusion. Analysis of biochemical data suggests that the active agent was not confined to the locale of the thrombus, but in fact circulated in significant concentration; furthermore, systemic (intravenous) treatment resulted in reperfusion of a significant proportion (50 percent) of coronary arteries as well. Comparative studies are needed to critically compare angiographic results after regional or systemic therapy and also to assess the impact of reperfusion on possible reduction in long-term morbidity and mortality. Although intracoronary therapy appears to be more effective for inducing reperfusion, intravenous therapy has the potential for greater clinical impact, since it can be instituted more quickly after the onset of symptoms and does not require specialized cardiac catheterization facilities.