Thrombolytic therapy for acute myocardial infarction: a brief review.

Thrombolytic therapy given within the first 4 to 6 hours to patients with evolving acute MI appears to reduce in-hospital and 1-year mortality rates. In addition, patients who receive treatment in the first few hours may also benefit through improved residual left ventricular function, resulting from the preservation of ischemic myocardium. Newer agents that are more effective in lysing intracoronary thrombi are currently under development. The most promising is tissue-type plasminogen activator (t-PA), which is being evaluated in a number of large multicenter trials, including the National Heart, Lung, and Blood Institute's Thrombolysis in Myocardial Infarction (TIMI) trial. In this study researchers are also comparing the additional value of early versus delayed coronary artery angioplasty and are evaluating a subset of patients randomly assigned to early beta-blocker therapy to assess the value of adjunctive pharmacologic therapy. In the future, it is likely that studies will be carried out to determine the usefulness of thrombolytic therapy given to patients by paramedics before hospitalization. Such a study is being planned in several communities. It is hoped that by means of prehospital therapy, it may be possible to treat a substantial group of patients with symptoms and electrocardiographic findings of acute MI before extensive left ventricular myocardial necrosis has occurred. If this goal can be realized, it may be possible to achieve a very substantial reduction in mortality resulting from acute MI. Initial experience with prehospital intravenous streptokinase therapy has already been reported from Jerusalem, Israel.(ABSTRACT TRUNCATED AT 250 WORDS)