E105 JACC March 12, 2013 Volume 61, Issue 10
Acute Coronary Syndromes Ticagrelor versus Ticagrelor and Clopidogrel in Patients undergoing Primary PCI: A Platelet Reactivity Pharmacodynamics Study Oral Contributions West, Room 3001 Sunday, March 10, 2013, 9:00 a.m.-9:15 a.m.
Session Title: ACS: Therapies on the Horizon Abstract Category: 1. Acute Coronary Syndromes: Clinical Presentation Number: 912-7 Authors: Benjamin M. Hibbert, Ronnen Maze, Ali Pourdjabbar, Trevor Simard, Daniel Ramirez, Michael Froeschl, Alexander Dick, Chris Glover, JeanFrancois Marquis, Marino Labinaz, Derek So, Michel Le May, University of Ottawa Heart Institute, Ottawa, Canada Objectives: To assess the effect of combination ticagrelor 180 mg and clopidogrel 600 mg (TC) on platelet reactivity compared to ticagrelor (T) alone in patients undergoing primary PCI. Background: Rapid platelet inhibition is needed to prevent stent thrombosis in patients undergoing primary PCI. In the PLATO study, increasing doses of pre-randomization clopidogrel was associated with a trend towards clinical benefit in STEMI patients assigned to ticagrelor. Methods: We measured platelet reactivity at multiple time points within 48 hours of loading with either T or TC in patients referred for primary PCI (PPCI) using the VerifyNow P2Y12 assay. Results: In total, 376 time points were assayed in STEMI patients (25 TC and 22 T) referred for PPCI. Mean baseline PRUs were similar between the groups (Figure, p=NS). By 2 hours, curves between the groups began separating with significantly lower PRUs observed in the TC arm at all remaining time points. Similarly, when analyzed as a categorical variable (PRU <208), combination therapy resulted in significantly more pts achieving therapeutic platelet inhibition at 1, 2, 4 and 6 hours. Conclusions: In patients referred for PPCI, loading with TC or T alone provided rapid and efficacious platelet inhibition; however, the combination of TC resulted in more rapid and more profound inhibition of platelet activity than T alone. Further studies are needed to determine if this pharmacodynamic interaction reduces clinical events.