Glycoprotein Iib/Iiia Receptor Antagonists: A Review of the Pivotal Trials

Abstract

A statistically significant reduction in the composite endpoint was seen for patients who received the abciximab bolus plus infusion vs those who received a placebo (P = 0.008). This benefit was maintained at 6 months and at 3 years. Also noteworthy in this trial was the increased number of bleeding complications experienced by patients who received the abciximab bolus plus infusion regimen. Heparin dosing was quite liberal in this study, and infusions continued for at least 12 hours (1). The 2792 patients included in the EPILOG study were undergoing elective or urgent revascularization procedures. Patients could be at all risk levels, but those with UA or acute MI were excluded. Heparin dosing was adjusted for weight, which was not done in the EPIC trial. The primary endpoints for this study were death from any cause, MI or reinfarction, or severe MI requiring urgent CABG or repeat revascularization within 30 days. After the first interim analysis, statistical significance was reached between the responses of the abciximab plus low-dose heparin group vs the placebo group, and patient enrollment was therefore terminated. Patients in the placebo group had a higher rate of endpoint events (P < 0.001). The incidence of bleeding was not higher for patients receiving abciximab plus heparin therapy (2). The CAPTURE study was designed to evaluate patients with refractory UA. The primary endpoints were defined as death, MI, or the need for an urgent procedure to treat a recurrent ischemic episode. In contrast to the previously described abciximab studies, infusions were started 18 to 24 hours before the start of the scheduled angioplasty procedure and were continued for 1 hour afterwards. The study was discontinued prematurely, after 1265 patients were enrolled. At the third interim analysis, a statistically significant higher percentage of patients in the placebo group had reached the primary endpoint compared with those in the abciximab group (P = 0.0064) (3). The final abciximab study is the EPISTENT trial. Previous work had established that stenting was superior to balloon angioplasty because stenting reduced the need for repeat revascularization. Despite this technological advancement, the rates of death and MI had not decreased proportionately. The other