Effects of Ticagrelor on Myocardial Infarct Size

Ticagrelor (Brilinta; AstraZeneca Pharmaceuticals LP, Wilmington, DE, USA) is a direct acting, reversible, oral P2Y12 inhibitor.1) In the PLATelet inhibition and patient Outcomes (PLATO) study, compared to clopidogrel (Plavix; Bristol-Myers Squibb/Sanofi Pharmaceuticals, Bridgewater, NJ, USA), ticagrelor reduced the rate of death from vascular causes, myocardial infarction (MI), or stroke in patients with acute coronary syndrome.2) Prevention of MI and stent thrombosis, and thus cardiac death, may result from fast, potent and consistent inhibition of platelets by ticagrelor.3) However, the mechanism of ticagrelor benefits has not been fully elucidated. Recent animal studies demonstrated that ticagrelor reduces reperfusion injury and limits myocardial infarct size.4)5) On the contrary, in an electrocardiography substudy of the PLATO trial, ticagrelor did not improve ST-segment resolution in patients with ST-segment elevation.6) To date, data are limited regarding whether or not ticagrelor reduces myocardial infarct size compared with clopidogrel.