Association of ticagrelor vs clopidogrel with net adverse clinical events in STEMI patients with mild thrombocytopenia

Abstract Backgrounds Current guidelines advocate for aspirin plus ticagrelor as the preferred dual antiplatelet therapy (DAPT) for ST-elevation myocardial infarction (STEMI). However, there is a lack of consensus or guidelines to direct clinicians on managing STEMI patients with mild thrombocytopenia, defined as a platelet count of 100~150×109/L. Purpose This study aims to investigate the association between ticagrelor and clopidogrel with ischemic and hemorrhagic events in STEMI patients with a platelet count of 100~150×109/L. Methods A retrospective cohort study was conducted using Health and Medical Big Data Super Platform from January 2010 to June 2023.The study included STEMI-patients with a platelet count of 100~150×109/L who received DAPT consisting of aspirin and a P2Y12 receptor antagonist (either clopidogrel or ticagrelor) All STEMI patients with a platelet count of 100~150×109/L were included in the analysis with a follow-up of at least one year. The inverse probability of treatment weighting (IPTW) approach based on propensity score was utilized to balance observed confounders between treatments. The primary endpoint was net adverse events (NACE) at 1 year, including ischemic events (recurrent myocardial infarction or ischemic stroke), Bleeding Academic Research Consortium (BARC) classification ≥ 3, and cardiac death. Secondary outcomes were cardiac death, recurrent myocardial infarction, and ischaemic stroke. Results The study cohort consisted 2941 participants with median age of 69 years, and 21.0% were female. Following adjustment using the inverse probability of treatment weighting, ticagrelor and clopidogrel demonstrated similar NACE (aHR, 0.86; 95%CI, 0.60-1.23). Cardiac death (aHR, 0.69; 95%CI, 0.36-1.31), recurrent myocardial infarction (aHR, 0.94; 95%CI, 0.50-1.78), and ischaemic stroke (aHR, 0.62; 95%CI, 0.34-1.14) did not significantly differ between the two groups. Conclusion In routine clinical practice, among STEMI patients with a platelet count of 100~150×109/L ticagrelor compared with clopidogrel, was not associated with a significant difference in the risk of NACE at 1 year. Further research is warranted to assess whether ticagrelor is more effective than clopidogrel in this particular patient population.