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Biomarkers 2023, VoL. 28, No. 4, 354–357 Abstracts for the 17th Annual Biomarkers and Personalized Medicine in Cardiovascular Disease Symposiums for the 17th Annual Biomarkers and Personalized Medicine in Cardiovascular Disease Symposium 1. Ethnic differences in highsensitivity cardiac troponin T among patients with chest pain in the emergency department Karren C Wonga, Sutton Foxa, Nicholas Bevinsb, Robert Fitzgeraldb and Lori B. Danielsc aDepartment of medicine, University of California, san Diego, La Jolla, Ca, Usa; bDepartment of Pathology, University of California, san Diego, La Jolla, Ca, Usa; cDivision of Cardiovascular medicine, University of California, san Diego, La Jolla, Ca, Usa Background: High-sensitivity cardiac troponin (hs-cTn) assays are the cornerstone for diagnosis of acute myocardial infarction (AMI). Patient-level factors such as age and sex are relevant considerations when interpreting hs-cTn concentrations, especially in a real-world clinical setting of patients with multiple comorbidities. Small observational studies have suggested that baseline levels of hs-cTn may vary by race/ethnicity, suggesting that use of a 99th percentile upper limit of normal (ULN) cutpoint derived in a largely Caucasian population may not be suitable for diagnosis of AMI in all racial/ ethnic groups. We aimed to explore the relationship between hs-cTnT concentrations within the normal range among different ethnic groups, in a real-world Emergency Department (ED) population. Methods: This retrospective cohort study included all patients age >18 years presenting to the ED at the University of California, San Diego between May 2016 and July 2020 who had hs-cTnT measured for clinical care, with peak concentration less than the unisex 99th percentile (<19 ng/L). Continuous variables with non-normal distributions were log-transformed. Stepwise multivariable linear regression was used to assess the relationship between self-reported ethnicity and log(hs-cTnT) adjusted for age, sex, estimated glomerular filtration rate (eGFR) and body mass index (BMI). Variation inflation factor was <5 for all variables, suggesting no influence of collinearity. Results: Of the 10,362 patients included (52% female), mean age was 56 ± 17 years. Self-reported race/ethnicity included African American (11%), Asian (8%), Hispanic/Latino (4%), Caucasian (49%) and Mixed-Heritage (27%). Mean log(hs-cTnT) was 0.89 ± 0.18 [equating to hs-cTn 7.8 ± 1.5 ng/L]. Among racial/ethnic groups, Asians had the lowest concentration of hs-cTnT even after adjusting for age, sex, eGFR and BMI, (β = −0.03, [95% CI −0.04 to −0.02], p = 0.007). On average, Asians had an adjusted hs-cTnT concentration 1.07 ng/L less than Caucasians. African Americans had the highest concentration of hs-cTnT, on average 1.12 ng/L higher than Caucasians (β = 0.05, [95% CI 0.04–0.06], p < 0.001). Conclusions: Among adults presenting to the ED with hs-cTnT below the 99th percentile ULN, Asians had lower adjusted and unadjusted levels of hs-cTnT compared to Caucasians. These findings suggest that use of standard hs-cTnT cutpoints may result in underdiagnosis of AMI among Asians. Further study is needed to determine whether lower cutpoints for Asians can improve diagnostic sensitivity and outcomes in patients with suspected AMI.