Early clinical outcomes as a function of use of newer oral P2Y(12) inhibitors versus clopidogrel in the EUROMAX trial

OBJECTIVE: To ascertain whether different oral P2Y(12) 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(12) inhibitor was at the investigator’s discretion. In a prespecified analysis, we compared event rates with clopidogrel and newer oral P2Y(12) inhibitors (prasugrel, ticagrelor). Rates of the primary outcome (acute stent thrombosis) were examined as a function of the P2Y(12) inhibitor used for loading and 30-day outcomes (including major adverse cardiac events) as a function of the P2Y(12) 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(12) 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(12) 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 (p=0.029) or minor (p=0.025) bleeding and Thrombolysis In Myocardial Infarction minor bleeding (p=0.002), 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.