Intravenous Heparin, Thrombolytics, and Medical Marketing

Prior to 1988, little had been written about the benefit to risk ratio of adding heparin anticoagulation to intravenous thrombolytic therapy for patients with evolving myocardial infarction, and heparin was considered to be a relatively trivial issue in the overall scheme of coronary thrombolysis. In the past 2 years, however, a considerable body of new data has been derived from intensive clinical research, including the largest myocardial reperfusion trial thus far completed'.' and five smaller randomized, controlled angiographic Collectively, a major controversy* has developed without the requisite unequivocal data necessary for its resolution. In this article we will review the major findings of these studies and discuss a new trial that, in part, is intended to provide balance to the heparin controversy. The Gruppo Italian0 per lo Studio della Sopravvivenza nell' Infarto Miocardico (GISSI-2) trial with the International Study Group randomly assigned 20,891 patients with acute myocardial infarction to receive either tissue plasminogen activator (tPA) or streptokinase (SK). '7' The trial had a 2 x 2 factorial design, such that