Abstract 12438: Efficacy and Safety Evaluation of a Platelet Glycoprotein Ib Inhibitor for Patients With Non-ST Segment Elevation Myocardial Infarction

Abstract

Introduction: Platelet receptor glycoprotein Ib (GPIb) plays a crucial role in the first step of platelet adhesion. Hypothesis: We hypothesized that GPIb inhibitor would attenuate platelet aggregation without increasing bleeding risk. Methods: This was a prospective, multicenter, double-blind, placebo controlled, randomized trial in 90 Chinese patients with non-ST segment elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI). GPIb inhibitor was initially administered via intravenous bolus injections at three dosing levels (low dose of 2IU/60kg, moderate dose of 3IU/60kg, and high dose of 5IU/60kg), followed by continuous intravenous infusion at 0.002IU/kg/h for up to 48 hours. Primary endpoint was the inhibition of platelet aggregation measured at baseline, 5 minutes, 24 hours and 48 hours from the beginning of infusion as well as 4 hours after withdrawal. Safety endpoint was in-hospital major bleeding. Results: Ninety patients were randomly assigned to low dose group (n=20), moderate dose group (n=20), high dose group (n=20), and placebo group (n=30). Overall, the median age was 57.7 and 14.4% were female. There was no significant difference among the 4 groups for demographic, clinical and procedural characteristics. Higher inhibition of platelet aggregation occurred in each GPIb inhibitor dosing group, compared with placebo at each time point, with strongest antiplatelet effect found in high-dose group (Figure 1). The TIMI flow and myocardial blush grade did not differ significantly among the 4 groups. The 30-day mortality (0% vs 3.3%, p=0.33), non-fatal MI (0% vs 3.3%, p=0.33) and major bleeding (1.7% vs 3.3%, p=1.00) were rare and comparable between the patients receiving GPIb inhibitor and placebo. Conclusions: The current study demonstrated that intravenous platelet receptor GPIb inhibitor could be feasible and safe with significant antiplatelet effect among patients with NSTEMI undergoing PCI.