The era of coronary reperfusion in acute coronary care was made possible by the recognition that acute myocardial infarction is usually due to a ruptured atherosclerotic plaque with associated thrombosis. If the infarct artery becomes occluded, a typical electrocardiographic picture is produced and a wave-front of myocardial necrosis ensues. Reperfusion during the early postinfarction hours can halt this process and preserve myocardial function. Pooled analysis of data in almost 60,000 patients has shown that thrombolysis saves lives relative to no reperfusion therapy. Streptokinase has been the standard thrombolytic agent, but recent data from the GUSTO trial show that tissue plasminogen activator (t-PA) given in an accelerated dosing regimen saves one extra patient per hundred treated. The mechanism of benefit of t-PA is improved early and complete restoration of blood flow down the infarct artery. Economic analysis of the GUSTO data shows that t-PA is an "economically attractive" therapeutic technology with a cost-effectiveness ratio of approximately $33,000 per life-year added relative to streptokinase therapy. Because of the growth of managed care and other cost-containment forces, expensive new medical technologies will increasingly need to demonstrate that they produce extra medical benefits in appropriate measure for their extra costs.