Switching patients from clopidogrel to prasugrel in acute coronary syndrome: Effects of prasugrel loading dose on residual platelet reactivity

摘要

A combination of aspirin and P2Y12 inhibitors (thienopyridine or ticagrelor) is recommended with a high level of evidence for the treatment of acute coronary syndrome (ACS) [1,2]. The TRITON TIMI38 study [3,4] has shown that, compared with clopidogrel, prasugrel, a third generation thienopyridine P2Y12 blocker, decreases the recurrence of ischemic events in ACS. In stable patients receiving a maintenance dose of clopidogrel, switching from clopidogrel to prasugrel is associated with increased platelet inhibition and this effect is obtained within 2 h when a loading dose of 60 mg of prasugrel is given [5]. However, in ACS, the switch to prasugrel after a clopidogrel loading dose has not been assessed because pretreatment with clopidogrel was an exclusion criterion in the TRITON TIMI38 study [3,4]. Therefore, there is no consensus on the way to manage this switch in the early phase of ACS in patients who are not on a maintenance dose of clopidogrel but who have just received a clopidogrel loading dose before their admission to the cardiology unit. In particular, the optimal dose of prasugrel re-load (RL) in such patients is unknown.