Preadmission antiplatelet therapy and treatment effect of ticagrelor versus prasugrel in patients with acute coronary syndromes - a subgroup analysis of the ISAR-REACT 5 trial

To assess whether the efficacy and safety of ticagrelor versus prasugrel in patients with acute coronary syndromes (ACS) are influenced by preadmission treatment with aspirin and/or clopidogrel. Patients (n = 4018) were categorized into 2 groups: preadmission aspirin and/or clopidogrel group (n = 1455), and no preadmission aspirin or clopidogrel group (n = 2563). The primary endpoint was the composite of all-cause death, myocardial infarction, or stroke; the secondary safety endpoint was Bleeding Academic Research Consortium (BARC) type 3 to 5 bleeding, both at 1 year.Patients in the preadmission aspirin and/or clopidogrel group had a higher risk of ischemic events, but a similar risk of bleeding with patients in the no preadmission aspirin or clopidogrel group (cumulative incidences 10.5% vs. 6.7%, and 5.7% vs. 5.7%, respectively). The primary endpoint occurred in 81/717 patients assigned to ticagrelor and 69/738 patients assigned to prasugrel in the preadmission aspirin and/or clopidogrel group (11.5% vs. 9.5%; hazard ratio [HR] = 1.23; 95% confidence interval [CI], 0.89-1.69), and in 103/1295 patients assigned to ticagrelor and 68/1268 patients assigned to prasugrel in the no preadmission aspirin or clopidogrel group (8.0% vs. 5.4%; HR = 1.50 [1.10-2.03]; Pint = 0.382). BARC type 3 to 5 bleeding events did not differ between ticagrelor and prasugrel in patients in the preadmission aspirin and/or clopidogrel (6.2% vs. 4.5%), or no preadmission aspirin or clopidogrel (5.3% vs. 5.1%) groups (Pint = 0.541). In patients with ACS, preadmission therapy with aspirin and/or clopidogrel has no influence on the relative efficacy and safety of ticagrelor and prasugrel.