Nonadherence to ticagrelor versus clopidogrel and clinical outcomes in patients with ACS. Results from the CREA-ARIAM registry

Prior studies have not determined whether the effect of dual antiplatelet therapy (DAPT) cessation on the subsequent risk of major adverse cardiac events (MACE) varies by the choice of P2Y12-inhibitor after acute coronary syndrome (ACS). We performed a prespecified subanalysis of a multicenter, prospective registry of ACS patients discharged on ticagrelor or clopidogrel between 2015 and2019. Nonadherence to DAPT was categorized as physician-guided discontinuation and disruption due to adverse effects, nonadherence, or bleeding. The association between DAPT cessation and 1-year MACE was analyzed using multivariate time-updated Cox models with inverse probability of censoring weighted estimators. Out of 2180 patients, 174 (8.3%) prematurely discontinued DAPT (physician-guided, n=126; disruption, n=48). Nonadherent patients were older and had more comorbidities than those on DAPT. Compared with physician-guided discontinuation, disruption occurred earlier after discharge and was more frequent with ticagrelor than with clopidogrel. In time-varying analysis, DAPT cessation was associated with an increased risk of MACE (adjusted HR, 1.32, 95%CI, 1.10-1.76), largely driven by disruption (adjusted HR, 1.47, 95%CI, 1.22-1.73). There was an exponential increase in MACE risk after DAPT cessation within 90 days after ACS, especially after disruption of ticagrelor compared with clopidogrel (Pinteraction