Point-of-care measured platelet inhibition correlates with a reduced risk of an adverse cardiac event after percutaneous coronary intervention - Results of the GOLD (AU-Assessing Ultegra) multicenter study

Background-The optimal level of platelet inhibition with a glycoprotein (GP ) IIb/IIIa antagonist necessary to minimize thrombotic complications in pat ients undergoing a percutaneous coronary intervention (PCI) is currently un known. Methods and Results-Five hundred patients undergoing a PCI with the planned use of a GP IIb/IIIa inhibitor had platelet inhibition measured at 10 minu tes, 1 hour, 8 hours, and 24 hours after the initiation of therapy with the Ultegra Rapid Platelet Function Assay (Accumetrics). Major adverse cardiac events (MACEs: composite of death, myocardial infarction, and urgent targe t vessel revascularization) were prospectively monitored, and the incidence correlated with the measured level of platelet function inhibition at all time points. One quarter of all patients did not achieve greater than or eq ual to 95% inhibition 10 minutes after the bolus and experienced a signific antly higher incidence of MACEs (14.4% versus 6.4%, P=0.006). Patients whos e platelet function was <70% inhibited at 8 hours after the start of therap y had a MACE rate of 25% versus 8.1% for those <greater than or equal to>70 % inhibited (P=0.009). By multivariate analysis, platelet function inhibiti on greater than or equal to 95% at 10 minutes after the start of therapy wa s associated with a significant decrease in the incidence of a MACE (odds r atio 0.46, 95% CI 0.22 to 0.96, P=0.04). Conclusions-Substantial variability in the level of platelet function inhib ition is achieved with GP IIb/IIIa antagonist therapy among patients underg oing PCI. The level of platelet function inhibition as measured by a point- of-care assay is an independent predictor for the risk of MACEs after PCI.