Glycoprotein IIb IIIa blockade and thrombolytics: Early lessons from the SPEED and GUSTO IV trials

Reperfusion with a regimen of thrombolytic therapy, aspirin, and unfractionated heparin is limited by a number of factors. Only 50% to 60% of patients achieve early thrombolysis in myocardial infarction grade-3 flow within 90 minutes with the most effective thrombolytic regimens. Even after initial reperfusion is achieved, transient and permanent reocclusion occurs too often and is associated with high mortality rates. As more older patients are treated, intracranial hemorrhage is becoming more common. Finally, the risk of bleeding and procedural failure has been high in patients who received an acute percutaneous interventional procedure shortly after treatment with thrombolytic therapy. Given the important role of platelets in the thrombotic process and the relatively weak inhibitory effect of aspirin, it is reasonable to seek agents that will provide more profound platelet inhibition. Early studies with full-dose fibrinolytic and glycoprotein IIb/IIIa inhibitors have been promising, but concern about bleeding has hindered this strategy. Several recent trials have evaluated full-dose abciximab with reduced-dose fibrinolytic therapy and have yielded promising results.