Comparison of two platelet glycoprotein IIb/IIIa inhibitors, tirofiban andabciximab, for the prevention of ischemic events with percutaneous coronary revascularization.

Background: In the setting of percutaneous coronary revascularization, agen ts in the class known as platelet glycoprotein IIb/IIIa inhibitors have sig nificantly reduced the incidence of death or nonfatal myocardial infarction at 30 days. We assessed whether there are differences in safety or efficac y between two such inhibitors, tirofiban and abciximab. Methods: Using a double-blind, double-dummy design at 149 hospitals in 18 c ountries, we randomly assigned patients to receive either tirofiban or abci ximab before undergoing percutaneous coronary revascularization with the in tent to perform stenting. The primary end point was a composite of death, n onfatal myocardial infarction, or urgent target-vessel revascularization at 30 days. The trial was designed and statistically powered to demonstrate t he noninferiority of tirofiban as compared with abciximab. Results: The primary end point occurred more frequently among the 2398 pati ents in the tirofiban group than among the 2411 patients in the abciximab g roup (7.6 percent vs. 6.0 percent; hazard ratio, 1.26; one-sided 95 percent confidence interval of 1.51, demonstrating lack of equivalence, and two-si ded 95 percent confidence interval of 1.01 to 1.57, demonstrating the super iority of abciximab over tirofiban; P = 0.038). The magnitude and the direc tion of the effect were similar for each component of the composite end poi nt (hazard ratio for death, 1.21; hazard ratio for myocardial infarction, 1 .27; and hazard ratio for urgent target-vessel revascularization, 1.26), an d the difference in the incidence of myocardial infarction between the tiro fiban group and the abciximab group was significant (6.9 percent and 5.4 pe rcent, respectively; P = 0.04). The relative benefit of abciximab was consi stent regardless of age, sex, the presence or absence of diabetes, or the p resence or absence of pretreatment with clopidogrel. There were no signific ant differences in the rates of major bleeding complications or transfusion s, but tirofiban was associated with a lower rate of minor bleeding episode s and thrombocytopenia. Conclusions: Although the trial was intended to assess the noninferiority o f tirofiban as compared with abciximab, the findings demonstrated that tiro fiban offered less protection from major ischemic events than did abciximab . (N Engl J Med 2001;344:1888-94.) Copyright (C) 2001 Massachusetts Medical Society.