Temporal Trends and Clinical Implications of Cardiac Troponin Testing in Emergency Departments: A Multicenter Retrospective Study

<b>Background:</b> Cardiac troponin testing is central to evaluating suspected acute coronary syndromes, yet its expanding use may increase resource utilization in low-risk emergency department populations. <b>Methods:</b> We conducted a multicenter retrospective cohort study across three tertiary hospitals in South Korea (2017-2023) using harmonized electronic health record data integrated with the Observational Medical Outcomes Partnership Common Data Model (OMOP-CDM) and the National Emergency Department Information System (NEDIS). Visits were stratified into low, intermediate, and high risk by age and chest pain presentation, and cardiac troponin T was categorized as normal (<0.014 ng/mL), borderline (0.014-0.052 ng/mL), or elevated (>0.052 ng/mL). Outcomes included emergency department length of stay, hospital admission, 30-day revisit, 30-day coronary revascularization, and 30-day mortality. <b>Results:</b> Among 727,772 visits, troponin testing increased from 29.8% in 2017 to 45.5% in 2023. High-risk patients were consistently tested, whereas testing rose substantially in intermediate- and low-risk groups. In high-risk patients, normal troponin values were associated with lower 30-day revascularization and mortality, without prolonging length of stay or increasing admissions. In contrast, in lower-risk groups, testing was associated with longer stays and higher admissions without clear short-term clinical benefit. <b>Conclusions:</b> These findings support more targeted troponin testing protocols to optimize emergency department resource use while preserving diagnostic performance in higher-risk presentations.