The glycoprotein IIb/IIIa receptor antagonist abciximab reduces the risk of thrombotic complications with percutaneous coronary intervention, but also has been associated with higher bleeding rates.

In the Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes (GUSTO IV–ACS) trial, abciximab (either a 24-hour or 48-hour infusion) was compared with placebo in 7800 patients with an acute coronary syndrome. During study drug administration, 2% of the patients underwent a revascularization procedure.

In 1507 patients (19.3%), bleeding according to the Thrombolysis in Myocardial Infarction (TIMI) classification was observed while they were hospitalized or within 7 days. Ninety-eight patients (1.2%) had a major bleed, including 8 with intracranial hemorrhages. In 215 patients (2.8%), a minor bleed was reported, and in 1194 patients (15.3%), an insignificant bleed was reported. Bleeding was more frequent in patients receiving a 48-hour infusion of abciximab. Spontaneous bleeding was seen in 911 patients (11.7%). The other 596 patients had a bleeding event in conjunction with a procedure. The most significant predictors for bleeding with multivariable analysis were: use of low-molecular weight heparin, duration of abciximab infusion, region of hospitalization, performance of coronary artery bypass grafting or percutaneous coronary intervention (PCI), advanced age, and female sex. For major bleeding, the predictors were performance of coronary artery bypass grafting or PCI, long duration of abciximab administration, and advanced age.

Treatment with abciximab in patients with non-ST–elevation acute coronary syndromes is safe because major bleeding and stroke are rare, and most events are clinically manageable or have few clinical consequences. Guidelines for use of abciximab in combination with other antithrombotic agents developed for PCI should also be respected in acute coronary syndromes. Specific dosing guidelines for combination with low-molecular weight heparin must be developed for patients who subsequently will undergo a PCI.