[Elements of choice of thrombolytic agents in myocardial infarction]

Abstract

Five thrombolytic agents have been used in the acute phase of myocardial infarction: streptokinase, recombinant tissue plasminogen activator (rt-PA) and its acyl enzyme (APSAC), urokinase and pro-urokinase. Experience with the latter two agents is much more limited. The antigenicity, biological half-life, fibrino-specificity and cost are important parameters to be taken into account when choosing a therapeutic agent. The doses expressed in different units or in milligrams vary with the product used. Large scale clinical trials have not shown improved efficacy of new thrombolytic agents. The role of associated treatments, aspirin and/or heparin and their respective doses, the timing of their administration are also important elements in the evaluation of efficacy judged by the frequency of coronary recanalisation and early reocclusion. The haemorrhagic risk is difficult to assess and seems more related to heparin therapy than the prescription of aspirin. Mutants of rt-PA obtained by genetic engineering and other new thrombolytics are currently under evaluation to try and obtain new, more effective and safer thrombolytic agents.