Abciximab Before PCI Benefits Patients with NSTE ACS

Benefits are confined to patients with elevated troponin levels.

Percutaneous coronary intervention (PCI) is an established therapy for patients with non–ST segment elevation acute coronary syndromes (NSTE ACS). Clopidogrel, at a dose of 600 mg, achieves maximum inhibition of platelet aggregation within 2 hours. These authors assessed whether abciximab adds benefit for patients with NSTE ACS who are undergoing PCI after clopidogrel pretreatment. In a multicenter, randomized, double-blind, placebo-controlled study, 2202 patients were assigned to receive abciximab (0.25 mg/kg bolus, followed by 0.125 µg/kg/minute infusion for 12 hours plus 70 U/kg heparin bolus) or placebo (placebo bolus, followed by 12-hour infusion plus 140 U/kg heparin bolus).

The primary endpoint was a composite of death, myocardial infarction, or urgent target vessel revascularization within 30 days. Overall, the endpoint occurred in significantly fewer abciximab recipients than placebo recipients (8.9% vs. 11.9%), yielding a 25% reduction in relative risk. In the subset of patients with elevated troponin levels, the relative risk for the primary endpoint was reduced by 29% in the abciximab group, whereas in patients without elevated troponin, risk did not differ significantly between the two groups. There were no significant differences between the abciximab and placebo groups in the risk for major bleeding (1.4% and 1.4%), the risk for minor bleeding (4.2% and 3.3%), and the need for transfusion (2.5% and 2.0%).

Comment: Platelet activation and aggregability are greatly increased in patients with NSTE ACS. Administration of abciximab, in addition to clopidogrel and heparin, confers an additional advantage — but one that is confined to patients who present with elevated troponin levels.

— John A. Marx, MD, FAAEM, FACEP

Published in Journal Watch Emergency Medicine May 23, 2006

Source

Kastrati A et al. Abciximab in patients with acute coronary syndromes undergoing percutaneous coronary intervention after clopidogrel pretreatment: The ISAR-REACT 2 randomized trial. JAMA 2006 Apr 5; 295:1531-8.

Steinhubl SR and Charnigo R. Clopidogrel treatment prior to percutaneous coronary intervention: When enough isn’t enough. JAMA 2006 Apr 5; 295:1581-2.