Ticagrelor is a reversible direct acting P2Y12 antagonist, which has shown to be superior to
clopidogrel, in adjunct to aspirin, in preventing recurrent ischemic events. Ticagrelor is
considered a first line therapy to be administered as soon as possible in ACS patients.
However, the pharmacodynamic effects of ticagrelor at the recommended 180mg loading dose are
delayed in patients with STEMI undergoing primary PCI. The use of higher loading dose
regimens of ticagrelor has therefore been advocated. The proposed investigation will have a
prospective, randomized, parallel design in which STEMI patients undergoing primary PCI will
be randomized to receive three different loading dose of ticagrelor (180 mg, 270 mg and 360
mg). Pharmacodynamic testing will be performed at several time points to test our study
hypothesis that a higher loading dose regiment will achieve more promptly enhanced platelet
inhibitory effects.