Identification of High Platelet Reactivity Despite ADP P2Y Inhibitor Treatment: Two Populations in the Vasodilator-Stimulated Phosphoprotein Assay and Variable PFA-P2Y Shapes of Curve.

 Response to ADP P2Y receptor inhibition by clopidogrel can be evaluated by various techniques. Here, we compared a functional rapid point-of-care technique (PFA-P2Y) with the degree of biochemical inhibition assessed by the VASP/P2Y assay.  Platelet response to clopidogrel was investigated in 173 patients undergoing elective intracerebral stenting (derivation cohort  = 117; validation cohort  = 56).