The Roles and Issues of P2Y12 Percent Inhibition Assessed by VerifyNow Assay for Patients Undergoing Neurointervention: A Prospective Study

Abstract

Antiplatelet agents have an important role in the prevention of ischemic complications during endovascular treatment. The aim of this study was to identify correlations between the clinical outcomes of neurointervention. This study also aimed to determine the optimal cutoff for P2Y12 percent inhibition to prevent ischemic and bleeding complications and to confirm the accuracy of the cutoff value. A prospective study was conducted for all patients (n=66) who received antiplatelet therapy during neurointervention at Toyama University Hospital during a 25-month period. Platelet reactivity was measured before the procedure using the VerifyNow and filter pressure methods. The primary outcome was the 30-day incidence of adverse clinical events, defined as ischemic or bleeding events, in relation to P2Y12 percent inhibition distribution. Multivariate analysis showed that P2Y12 percent inhibition was an independent predictor for bleeding (P=.021, odds ratio [OR]=3.45; 95% confidence interval [CI], 2.31-4.88) and ischemic (P=.045, OR=3.63; 95% CI, 2.11-7.12) events. In receiver operating characteristic curve analysis, P2Y12 percent inhibition could significantly discriminate between patients with and without bleeding and ischemic events. The optimal cutoffs for bleeding (74%) and ischemic events (26%) were used to define 3 groups: those with poor response, sufficient response, and hyper-response. Ischemic and bleeding complications were significantly different among the 3 groups. Optimal threshold, measured using the VerifyNow P2Y12 assay, can be identified using specific thresholds (26%<percent inhibition<74%) to define patients at lower risk for ischemic and bleeding events. The threshold for hyper-response can highly predict bleeding events in perioperative period. On the other hands, cutoff value for poor response may be affected by various factors.