Platelet function analysis: a comparison of methods

Variability in response to clopidogrel has been well described, with residual platelet reactivity (RPR) after treatment in 5-44% of patients. New point-of-care (POC) devices have been developed in an attempt to identify poor responders at risk of adverse outcomes, with a view to eventually guide titration of anti-platelets. We sought to assess sensitivity/specificity of the Accumetrics VerifyNow device for measuring responsiveness to clopidogrel in patients undergoing elective PCI compared to the more specific tool: flow-cytometric analysis using VAsodilator-Stimulated Phosphoprotein (VASP). Our findings suggest that larger replication studies and standardised guidelines are required before POC devices may be routinely used in clinical practice.