Abciximab and Heparin Versus Bivalirudin for Non–ST-Elevation Myocardial Infarction

Study Questions:

What is the effect of abciximab with unfractionated heparin, as compared with bivalirudin, on clinical outcomes in patients with acute non–ST-segment elevation myocardial infarction (NSTEMI) who are undergoing percutaneous coronary intervention (PCI)?

Methods:

The ISAR-REACT 4 (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment 4) trial investigators randomly assigned, in a double-blind manner, 1,721 patients with acute NSTEMI to receive abciximab plus unfractionated heparin (861 patients) or bivalirudin (860 patients). The study tested the hypothesis that abciximab and heparin would be superior to bivalirudin with respect to the primary composite endpoint of death, large recurrent MI, urgent target vessel revascularization (TVR), or major bleeding within 30 days. Secondary endpoints included the composite of death, any recurrent MI, or urgent TVR (efficacy endpoint) and major bleeding (safety endpoint) within 30 days. The Kaplan–Meier method was used to assess event-free survival; comparisons were made with the use of the log-rank test.

Results:

The primary endpoint occurred in 10.9% of the patients in the abciximab group (94 patients) and in 11.0% in the bivalirudin group (95 patients) (relative risk [RR] with abciximab, 0.99; 95% confidence interval [CI], 0.74-1.32; p = 0.94). Death, any recurrent MI, or urgent TVR occurred in 12.8% of the patients in the abciximab group (110 patients) and in 13.4% in the bivalirudin group (115 patients) (RR, 0.96; 95% CI, 0.74-1.25; p = 0.76). Major bleeding occurred in 4.6% of the patients in the abciximab group (40 patients) as compared with 2.6% in the bivalirudin group (22 patients) (RR, 1.84; 95% CI, 1.10-3.07; p = 0.02).

Conclusions:

The authors concluded that abciximab and unfractionated heparin, as compared with bivalirudin, failed to reduce the rate of the primary endpoint and increased the risk of bleeding among patients with NSTEMI who were undergoing PCI.

Perspective:

This double-blind, randomized study reports that abciximab plus unfractionated heparin, as compared with bivalirudin, was not associated with a reduction in the risk of death, large recurrent MI, urgent TVR, or major bleeding at 30 days. Furthermore, incidence of the secondary safety endpoint, major bleeding, was significantly increased with abciximab plus unfractionated heparin. The results of the current trial in conjunction with other available evidence support the use of bivalirudin as the preferred antithrombotic drug during PCI in patients with NSTEMI.

Clinical Topics: Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention

Keywords: Incidence, Risk, Myocardial Infarction, Heparin, Recombinant Proteins, Peptide Fragments, Immunoglobulin Fab Fragments, Angioplasty, Balloon, Coronary, Hirudins, Stents, Percutaneous Coronary Intervention


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