Thrombolytic therapy in myocardial infarction.

Since its reintroduction in 1979, the administration of streptokinase for the treatment of myocardial infarction has revolutionised the management of this common condition. Intracoronary, and subsequently intravenous infusion of this lytic agent have been shown to recanalise the totally occluded infarct related vessel. Overall mortality reduction was 18% when it was administered intravenously in the GISSI study. The survival advantage has been maintained over 1-2 years. The addition of aspirin has increased the survival rate, as reported in the ISIS-2 study. Recombinant tissue plasminogen activator, a clot specific agent, achieves a higher patency rate when compared to streptokinase, besides favourably influencing survival. Both drugs also improve left ventricular function. Complications include a 0.5-1% incidence of intracranial haemorrhage, as well as a small risk of major bleeding. Although the incidence is low, reinfarction is increased after thrombolytic therapy. Hence, some form of assessment of residual myocardial ischaemia should be performed. Routine PTCA after thrombolysis has not been shown to be of additional benefit. The introduction of more potent and clot specific drugs without unwanted side effects are eagerly awaited.