Ability of the INNOVANCE PFA P2Y system to detect clopidogrel-induced ADP receptor blockade in preangiocath individuals.

We compared the ability of four test systems to detect platelet P2Y12 (ADP receptor) blockade by clopidogrel. The systems were the INNOVANCE PFA P2Y cartridge (PFA P2Y), the Accumetrics VerifyNow P2Y12 cartridge (VN P2Y12), whole blood aggregometry (WBA) using 5 (WBA 5) and 10 (WBA 10)  μmol/l ADP, and light transmittance aggregometry (LTA) using 20 (LTA 20)  μmol/l ADP. Blood was collected in 3.2% citrate from 101 preangiography participants who had received 300-600  mg of clopidogrel within 6-24  h or 75  mg daily for at least 7 days. Blood was also collected in 3.8% citrate for the PFA P2Y. Cut-offs indicating blockade were PFA P2Y, more than 106  s; VN P2Y12, less than 20%,  less than  235 Plavix resistance unit (PRU); WBA 5, less than 5  ohms; WBA 10, less than 8  ohms; and LTA 20, less than 50% aggregation. Percentage positives were PFA P2Y (3.2% citrate), 59%; PFA P2Y (3.8% citrate), 95%; VN P2Y12, 60%; VN P2Y12 PRU, 50%; WBA 5, 88%; WBA 10, 89%; and LTA 20, 72%. Percentage agreements were PFA P2Y 3.2% to VN P2Y12, 71%; PFA P2Y 3.2% to WBA 5 and 10, 64 and 65%, respectively; PFA P2Y 3.2% to LTA 20, 69%; PFA P2Y 3.8% to VN P2Y12, 71%, and to VN P2Y12 PRU, 60%; PFA P2Y 3.8% to WBA 5 and 10, 90% for both; PFA P2Y 3.8% to LTA 20, 76%; VN P2Y12 to WBA 5 and 10, 68 and 67%, respectively; and VN P2Y12 to LTA 20, 72%. PFA P2Y (3.2% citrate) detection compared favorably to VN P2Y12. The same system at 3.8% citrate compared more closely to WBA 5 and WBA 10.