Thrombolytic therapy in the management of acute myocardial infarction (MI) shows true evidence of benefit. Administration of a thrombolytic saves about 30 lives per 1,000 in those presenting within six hours of symptom onset but only 20 lives per 1,000 when patients receive treatment between six and 12 hours after symptom onset. After 12 hours there appears to be only a small and statistically uncertain benefit.
The aim in thrombolysis should be to increase the number of patients who achieve TIMI grade 3 flow as soon as possible after the occlusive event. Additional benefit in improving thrombolysis, particularly in reducing 30-day mortality, has been shown by adding the antiplatelet agent, aspirin, to thrombolytic therapy. The addition of a second antiplatelet agent, such as clopidogrel, has been shown to be of benefit in other, less immediately severe atherothrombotic manifestations (unstable angina and non-ST-elevation MI) and looks to be a promising development in the management of acute ST-elevation MI. The potential advantages of dual antiplatelet therapy in this setting, investigated in the recently published CLARITY study, are discussed.
