Correlation Between the VerifyNow P2Y 12 Assay and the Newly Developed APAL System in Neuroendovascular Patients.

Objective. Light transmission aggregometry (LTA) is the gold standard method for assessing platelet function. Recently, a new parameter called adenosine diphosphate (ADP)-induced platelet aggregation level (APAL) was developed to aid interpretation of LTA results. APAL is a score calculated based on platelet aggregation patterns upon exposure to 1 mu M and 10 mu M ADP and is determined using an automated coagulation analyzer. We compared APAL and VerifyNow P2Y(12) assay for neuroendovascular patients. Methods. 42 patients who have received antiplatelet therapy were studied. Platelet function tests were performed on CS-2400 for APAL and VerifyNow P2Y(12) assay was used for P2Y(12) reaction unit (PRU) and % inhibition. Results. Moderate correlations were observed between APAL and PRU (r=0.64, p<0.001) and between APAL and % inhibition (r=-0.74, p<0.001). The optimal threshold for APAL was 8.2 for PRU (threshold=240) and 8.1 for % inhibition (threshold=26%). The percentage of agreement between the above thresholds was 90.9% between PRU and APAL and 77.3% between % inhibition and APAL. Conclusions. The APAL system exhibits moderate correlation with PRU and % inhibition. APAL testing is a good choice for a clinical laboratory already in possession of Sysmex CS series analyzers. In this setting, APAL testing can significantly decrease the cost of platelet function testing for patients on antiplatelet therapy.