Efficacy and safety comparing prasugrel/ticagrelor and clopidogrel in Hong Kong post-acute coronary syndrome patients-A 10-year cohort study

Background Clinical evidence of prasugrel/ticagrelor in dual antiplatelet therapy (DAPT) in Asian acute coronary syndrome (ACS) population remains inconclusive. We aimed to compare the clinical efficacy and safety of prasugrel/ticagrelor compared to clopidogrel as part of DAPT in Hong Kong ACS population for 10 years. Hypothesis Prasugrel/ticagrelor, compared to clopidogrel, reduces risk of major adverse cardiovascular event (MACE) in Hong Kong ACS population. Methods The retrospective observational cohort study included patients admitted to seven institutions under Hospital Authority Hong Kong with diagnosis of ACS during 2008-2017. Risk of MACE, defined as composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and non-fatal stroke, and risk of any bleeding leading to hospitalization were examined. Baseline characteristics difference was adjusted by propensity score (PS) matching. Adjusted Cox regression model was used to estimate hazard ratio of interested outcome. Results In PS matched cohort including 944 patients in each group, MACE risk reduction of 40% from 1 year to 5 years after index ACS event was observed in prasugrel/ticagrelor group (HR 0.60, 95% CI 0.39-0.91, p = .015). The risk reduction was highly driven by MI reduction (HR 0.54, 95% CI 0.33-0.91, p = .019). Lower bleeding risk was observed in prasugrel/ticagrelor group compared to clopidogrel from 1 year to 5 years (HR 0.46, 95% CI 0.21-1.00, p = .051). Conclusions Prasugrel/ticagrelor showed MACE risk reduction over clopidogrel as part of DAPT up to 5 years after index event, while prasugrel/ticagrelor was not associated with increased bleeding risk.