Ticagrelor Versus Clopidogrel in Patients with Acute Coronary Syndrome and Chronic Kidney Disease: A Real-World Analysis from a National Registry

<i>Background and Objectives:</i> Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is standard care for acute coronary syndrome (ACS). Although ticagrelor showed superiority over clopidogrel in pivotal trials, patients with advanced chronic kidney disease (CKD) or on dialysis were underrepresented and results in Asian populations have been inconsistent. <i>Materials and Methods:</i> We conducted a retrospective cohort study using the Taiwan Society of Cardiology Acute Coronary Syndrome-Diabetes Mellitus (TSOC ACS-DM) registry between 1 October 2013, and 30 September 2016. Eligible patients had type 2 diabetes mellitus and ACS with stage III-V CKD or were on dialysis at index hospitalization and were discharged on aspirin plus either ticagrelor or clopidogrel. The primary endpoint was a composite of cardiovascular (CV) death, CV-related readmission, and repeated revascularization. Cumulative incidence functions were compared using expectation maximization (EM) weighting and propensity score adjustment. <i>Results</i>: After exclusions, 451 patients were analyzed (ticagrelor n = 116; clopidogrel n = 335). Ticagrelor associated with higher myocardial infarction (HR 1.59, 95% CI 1.12-2.28, <i>p</i> = 0.010), CV-related readmission (HR 1.72, 95% CI 1.12-2.65, <i>p</i> = 0.014), repeated revascularization (HR 2.24, 95% CI 1.36-3.68, <i>p</i> = 0.002), and the composite endpoint (HR 1.63, 95% CI 1.06-2.48, <i>p</i> = 0.024) at 2 years. <i>Conclusions</i>: Among real-world Taiwanese patients with type 2 diabetes mellitus, ACS, and CKD, ticagrelor use was linked to increased risks of cardiovascular events compared to clopidogrel. However, these relationships might be affected by potential confounding factors. Randomized controlled trials are necessary to establish the best antiplatelet strategy for this high-risk group.