Abstract 4947: Maintenance Treatment With Ticagrelor Yields Greater and More Consistent Inhibition of Platelet Function Compared to Clopidogrel in Patients With Acute Coronary Syndromes: Results From the PLATO PLATELET Substudy
Background: The PLATO study compared the efficacy of ticagrelor (T), an oral reversible P2Y12 receptor antagonist, and clopidogrel (C) in patients with non ST elevation ACS or primary PCI-treated STEMI patients. In the PLATO PLATELET substudy, we assessed the extent of inhibition of platelet function in PLATO study patients.
Methods and Results: 69 patients randomised in the PLATO study to receive maintenance therapy with either C 75mg qd (n=32) or T 90mg bid (n=37) underwent platelet function testing after at least 28 days of treatment. Light transmittance aggregometry (LTA) with ADP (5 and 20 uM), VerifyNow P2Y12 (VN) and VASP assays were performed prior to maintenance dose (‘trough’) and 2– 4h after dosing (‘peak’) in all patients. Mean % maximum LTA response induced by ADP 20 uM at trough was 48±14 and 36±12% (p<0.001) and at peak was 44±15 and 28±10% for C and T respectively (p<0.0001)(Figure⇓). Similar patterns were seen for ADP 5 uM. VN values at trough were 214±79 and 79±78 PRU for C and T and at peak were 196±95 and 31±32 PRU respectively (both p<0.0001)(Figure⇓). PRI values at trough were 55±22 and 27±21% for C and T and at peak were 44±21 and 14±13% respectively (both p<0.0001). VN and VASP at peak particularly showed more consistency and less variability in response with T compared to C.
Conclusion: Maintenance therapy with ticagrelor 90mg bid in patients with ACS achieves greater and more consistent inhibition of platelet function compared to standard clopidogrel therapy.