Early clinical outcomes as a function of use of newer oral P2Y inhibitors versus clopidogrel in the EUROMAX trial.

Objective: To ascertain whether different oral P2Y inhibitors might affect rates of acute stent thrombosis and 30-day outcomes after primary percutaneous coronary intervention (pPCI).

Methods: The European Ambulance Acute Coronary Syndrome Angiography (EUROMAX) randomised trial compared prehospital bivalirudin with heparin with optional glycoprotein IIb/IIIa inhibitor treatment in patients with ST-segment elevation myocardial infarction triaged to pPCI. Choice of P2Y inhibitor was at the investigator's discretion. In a prespecified analysis, we compared event rates with clopidogrel and newer oral P2Y inhibitors (prasugrel, ticagrelor). Rates of the primary outcome (acute stent thrombosis) were examined as a function of the P2Y inhibitor used for loading and 30-day outcomes (including major adverse cardiac events) as a function of the P2Y inhibitor used for maintenance therapy. Logistic regression was used to adjust for differences in baseline characteristics.

Results: Prasugrel or ticagrelor was given as the loading P2Y inhibitor in 49% of 2198 patients and as a maintenance therapy in 59%. No differences were observed in rates of acute stent thrombosis for clopidogrel versus newer P2Y inhibitors (adjusted OR 0.50, 95% CI 0.13 to 1.85). After adjustment, no difference was observed in 30-day outcomes according to maintenance therapy except for protocol major (p0.029) or minor (p0.025) bleeding and Thrombolysis In Myocardial Infarction minor bleeding (p0.002), which were less frequent in patients on clopidogrel. Consistent results were observed in the bivalirudin and heparin arms.

Conclusions: The choice of prasugrel or ticagrelor over clopidogrel was not associated with differences in acute stent thrombosis or 30-day ischaemic outcomes after pPCI.

Trial Registration Number: NCT01087723.