Point-of-Care Measurement of Clopidogrel Responsiveness Predicts Clinical Outcome in Patients Undergoing Percutaneous Coronary Intervention Results of the ARMYDA-PRO (Antiplatelet therapy for Reduction of MYocardial Damage during Angioplasty-Platelet Reactivity Predicts Outcome) Study

ObjectivesThe aim of this study was to evaluate the correlation of point-of-care measurement of platelet inhibition with clinical outcome in patients undergoing percutaneous coronary intervention (PCI).BackgroundIndividual variability of clopidogrel response might influence results of PCI.MethodsA total of 160 patients receiving clopidogrel before PCI were prospectively enrolled. Platelet reactivity was measured by the VerifyNow P2Y12 assay (Accumetrics Inc., San Diego, California). Primary end point was 30-day occurrence of major adverse cardiac events (MACE) according to quartile distribution of P2Y12 reaction units (PRU).ResultsPrimary end point occurred more frequently in patients with pre-procedural PRU levels in the fourth quartile versus those in the lowest quartile (20% vs. 3%; p = 0.034), and it was entirely due to periprocedural myocardial infarction (MI). Mean PRU absolute levels were higher in patients with periprocedural MI (258 ± 53 vs. 219 ± 69 in patients without; p = 0.030). On multivariable analysis pre-PCI PRU levels in the fourth quartile were associated with 6-fold increased risk of 30-day MACE (odds ratio: 6.1; 95% confidence interval: 1.1 to 18.3, p = 0.033). By receiver-operating characteristic curve analysis, the optimal cut-off for the primary end point was a pre-PCI PRU value ≥240 (area under the curve: 0.69; 95% confidence interval: 0.56 to 0.81, p = 0.016).ConclusionsThis study indicates that high pre-PCI platelet reactivity might predict 30-day events. Use of a rapid point-of-care assay for monitoring residual platelet reactivity after clopidogrel administration might help identify patients in whom individualized antiplatelet strategies might be indicated with coronary intervention