Abciximab in Patients With Acute ST-Segment–Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention After Clopidogrel Loading

Background— The glycoprotein IIb/IIIa receptor inhibitor abciximab has improved the efficacy of primary percutaneous coronary interventions in patients with acute myocardial infarction. However, it is not known whether abciximab remains beneficial after adequate clopidogrel loading in patients with acute ST-segment–elevation myocardial infarction.Methods and Results— A total of 800 patients with acute ST-segment–elevation myocardial infarction within 24 hours from symptom onset, all treated with 600 mg clopidogrel, were randomly assigned in a double-blind fashion to receive either abciximab (n=401) or placebo (n=399) in the intensive care unit before being sent to the catheterization laboratory. The primary end point, infarct size measured by single-photon emission computed tomography with technetium-99m sestamibi before hospital discharge, was 15.7±17.2% (mean±SD) of the left ventricle in the abciximab group and 16.6±18.6% of the left ventricle in the placebo group (P =0.47). At 30 days, the composite of death, recurrent myocardial infarction, stroke, or urgent revascularization of the infarct-related artery was observed in 20 patients in the abciximab group (5.0%) and 15 patients in the placebo group (3.8%) (relative risk, 1.3; 95% CI, 0.7 to 2.6;P =0.40). Major bleeding complications were observed in 7 patients in each group (1.8%).Conclusion— Upstream administration of abciximab is not associated with a reduction in infarct size in patients presenting with acute myocardial infarction within 24 hours of symptom onset and receiving 600 mg clopidogrel.