Thrombolytic therapy in Europe: current status

Thrombolytic therapy is a practical, effective approach to the management of acute myocardial infarction that is widely used in Europe today. Early European trials demonstrated a clear reduction in mortality in patients who received thrombolytic therapy compared with those given conventional treatment. The findings of experimental studies suggest that early reperfusion of the infarct-related artery reduces myocardial damage, which results in the preservation of left ventricular function and, in turn, may improve survival. Although tissue plasminogen activator (t-PA) has been shown to produce more rapid and complete reperfusion than streptokinase, two large-scale clinical trials in which t-PA was given as a standard 3- or 4-h infusion provided no evidence of a survival advantage with this agent. However, the accelerated t-PA regimen used in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) study was associated with a lower mortality than streptokinase or a combination of t-PA and streptokinase, thus lending support to the 'open artery' theory. Two recent studies conducted in Europe, the Grampian Region Early Anistreplase Trial (GREAT) and the European Myocardial Infarction Project (EMIP), have demonstrated the feasibility, safety, and efficacy of early thrombolytic therapy before admission to hospital. In GREAT, anistreplase (APSAC) was administered at home by general practitioners. In EMIP, this same agent was given by emergency medical personnel. In both studies, pre-hospital administration reduced the time between the onset of symptoms and initiation of thrombolysis and was associated with a lower mortality rate. Recent data from the European Cooperative Group Study show that the benefits of thrombolytic therapy are maintained for up to 5 years. Research continues in an effort to develop safer and more effective thrombolytic agents. Educational efforts to familiarize the public with the symptoms of myocardial infarction and the development of more rapid, efficient emergency response systems may also improve the outcome of thrombolytic therapy by shortening the time between symptom onset and thrombolytic drug administration.