Platelet Membrane Receptor Glycoprotein IIb/IIIa Antagonism in Unstable Angina The Canadian Lamifiban Study

Background Ligand binding to the platelet membrane receptor glycoprotein (GP) IIb/IIIa, the final and obligatory step to platelet aggregation, can now be inhibited by pharmacological agents. This study was designed to evaluate the potential of lamifiban, a novel nonpeptide antagonist of GP IIb/IIIa, for the management of unstable angina. Methods and Results In a prospective, dose-ranging, double-blind study, 365 patients with unstable angina were randomized to an infusion of 1, 2, 4, or 5 μg/min of lamifiban or of placebo. Treatment was administered for 72 to 120 hours. Outcome events were measured during the infusion period and after 1 month. Concomitant aspirin was administered to all patients and heparin to 28% of patients. Lamifiban, all doses combined, reduced the risk of death, nonfatal myocardial infarction, or the need for an urgent revascularization during the infusion period from 8.1% to 3.3% (P=.04). The rates were 2.5%, 4.9%, 3.3%, and 2.4% with increasing doses. At 1 month, death or nonfatal ...