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

Abstract Backgrounds: Guidelines currently recommend aspirin plus ticagrelor as the preferred dual antiplatelet therapy (ADPT) for non-ST-elevation myocardial infarction (NSTEMI). However, there are no established recommendations for managing NSTEMI 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 NSTEMI patients with a platelet count of 100~150×109/L. Methods A retrospective cohort study was conducted using data from the Health and Medical Big Data Super Platform from January 2010 to June 2023. The study included NSTEMI patients with a platelet count of 100~150×109/L who received DAPT consisting of aspirin and a P2Y12 receptor antagonist (eithor clopidogrel or ticagrelor). Patients were followed up for at least one year. The inverse probability of treatment weighting (IPTW) approach based on propensity score was used to balance the observed confounders between treatments. The primary endpoint was net adverse events (NACE) at 1 year, composed of ischemic events (recurrent myocardial infarction or ischemic stroke), Bleeding Academic Research Consortium (BARC) classification ≥ 3, and cardiac death. Secondary outcomes included cardiac death, recurrent myocardial infarction and, ischemic stroke. Results The study cohort comprised 2969 participants, with a median age of 72 years and 29.2.0% female. After adjustment using inverse probability of treatment weighting, ticagrelor and clopidogrel showed similar rates of NACE (aHR, 0.84; 95%Cl, 0.58-1.21). Cardiac death (aHR, 0.99; 95%Cl, 0.54-1.83) and ischemic stroke (aHR, 0.94; 95%Cl, 0.49-1.81) did not significantly differ between the two groups. However, ticagrelor was associated with a lower rate of recurrent myocardial infarction (aHR, 0.44; 95%Cl, 0.21-0.93). Conclusion In routine clinical practice, among NSTEMI patients with a platelet count of 100~150×109/L, ticagrelor, did not showed a significant difference in the risk of NACE at 1 year compared with clopidogrel. However, ticagrelor was associated with a lower rate of recurrent myocardial infarction. Further research is warranted to confirm the this conclusion.