Timing of Oral P2Y12 Inhibitor Administration in Non-ST Elevation Acute Coronary Syndrome

Background Although oral P2Y12 inhibitors are key in the management of patients with non-ST elevation acute coronary syndrome (NSTE-ACS), the optimal timing of their administration is not well defined. Objective to compare downstream and upstream oral P2Y12 inhibitors administration strategies in NSTE-ACS patients undergoing invasive management. Methods We performed a randomized, adaptive, open-label, multi-center, clinical trial. Patients were randomly assigned to receive pre-treatment with ticagrelor before angiography (upstream group) or no pre-treatment (downstream group). Patients in the downstream group undergoing percutaneous coronary intervention (PCI) were further randomized to receive ticagrelor or prasugrel. The primary hypothesis was superiority of the downstream over the upstream strategy on the combination of efficacy and safety events (net clinical benefit). Results We randomized 1449 patients to downstream or upstream oral P2Y12 inhibitor administration. A prespecified stopping rule for futility at interim analysis led the trial to be stopped. The rate of the primary endpoint, a composite of death due to vascular causes, non-fatal myocardial infarction or non-fatal stroke, and Bleeding Academic Research Consortium (BARC) type 3, 4 and 5 bleedings through day 30, did not differ significantly between the downstream and upstream groups (Absolute Risk Reduction (ARR%) -0.46 [-2.90; 1.90]).These results were confirmed among patients undergoing PCI (72% of population) and regardless of the timing of coronary angiography (within or after 24 hours from enrolment). Conclusions Downstream and upstream oral P2Y12 inhibitors administration strategies were associated with low incidence of ischemic and bleeding events and minimal numerical difference of event rates between treatment groups. These findings led to premature interruption of the trial and suggest the unlikelihood of enhanced efficacy of one strategy over the other. [Funded by the Italian Society of Interventional Cardiology (SICI-GISE)]