Effects of P2Y12 Receptor Inhibition in Patients With ST-Segment Elevation Myocardial Infarction

In ST-segment elevation myocardial infarction (STEMI), an effective antiplatelet treatment adjunctive to primary percutaneous coronary intervention is of utmost importance. High dose of clopidogrel, prasugrel, or ticagrelor provides a faster, more potent, and more consistent platelet inhibition than standard clopidogrel. Oral P2Y12 inhibitors have been studied in large clinical trials and are in use in clinical practice. Intravenously administered P2Y12 inhibitors such as cangrelor have also been tested. However, statistically significant anti-ischemic superiority of stronger platelet inhibition regimens versus standard clopidogrel has not been proved exclusively in patients receiving primary percutaneous coronary intervention. Whether orally administered antiplatelet agents suffice in patients with STEMI has been recently disputed, mainly because of their delayed onset of action. Platelet reactivity variability before P2Y12 blockade and its evolution over time, genetic predisposition, antiplatelet agent used, timing, and method of platelet function testing significantly affect the rates of high on-treatment platelet reactivity. Although ominous signs of greater bleeding potential of stronger antiplatelet regimens have not appeared in STEMI, this should be carefully tested.