Comparative Effectiveness and Safety of Ticagrelor Versus Clopidogrel for Elderly Chinese Patients Undergoing Percutaneous Coronary Intervention: A Single-Center Retrospective Cohort Study

Background Taking ischemic and bleeding risks into consideration, insufficient data exist on dual antiplatelet therapy after percutaneous coronary intervention in elderly Chinese patients with coronary artery disease. Objective We aimed to investigate the effectiveness and safety of ticagrelor in comparison with clopidogrel on a background of aspirin for elderly Chinese patients with coronary artery disease 12 months after percutaneous coronary intervention. Methods A single-center retrospective cohort study was conducted. Selected from patients with coronary artery disease aged ≥ 75 years from January 2010 to July 2019, 908 eligible subjects receiving dual antiplatelet therapy after percutaneous coronary intervention for up to 12 months were consecutively enrolled in the study. The included patients received ticagrelor in combination with aspirin ( n = 264) or clopidogrel in combination with aspirin ( n = 644). Effectiveness endpoints were evaluated by the major adverse cardiovascular events, encompassing all-cause death, non-fatal myocardial infarction, and clinically driven revascularization. The safety endpoints were recorded as the incidence of Bleeding Academic Research Consortium bleeding. Results The patients who were treated with ticagrelor were slightly younger than those who were treated with clopidogrel (79.1 ± 3.7 vs 80.7 ± 4.5 years, p < 0.01). The ticagrelor cohort contained a higher percentage of patients undergoing a prior percutaneous coronary intervention (37.9% vs 24.5%, p < 0.01), and a lower percentage of smokers (19.3% vs 27.2%, p < 0.05), compared with the clopidogrel cohort. The levels of glucose, total cholesterol, and low-density lipoprotein-cholesterol in the ticagrelor group were higher while the level of triglycerides and high-density lipoprotein-cholesterol were lower ( p < 0.05) than those in the clopidogrel group. Left main percutaneous coronary intervention was performed more frequently among the ticagrelor-treated patients (23.5% vs 9.3%, p < 0.01), while patients in the clopidogrel group underwent more left circumflex percutaneous coronary intervention (34.3% vs 23.1%, p < 0.01). We found that ticagrelor was associated with a lower incidence of major adverse cardiovascular events than clopidogrel using the inverse probability of treatment weighting model (odds ratio, 0.493; 95% confidence interval 0.356–0.684). There was no difference in terms of the risk of Bleeding Academic Research Consortium bleeding between the two groups ( p > 0.05). Conclusions Ticagrelor was associated with a lower incidence of major adverse cardiovascular events than clopidogrel at 12 months in elderly Chinese patients with coronary artery disease, without a significant increase of Bleeding Academic Research Consortium bleeding events.