Abstract 13919: Race and Gender Specific High Sensitivity Troponin-t Cutoff Values Improve Detection in Patients’ With Ischemic Heart Disease

Abstract

Introduction: Death rates from acute coronary syndrome events (ASCE) are 30% higher in African Americans than in Caucasians. A potential reason for this disparity is the underdiagnosis of ACSE due to race-specific differences in blood levels of cardiac troponin-T (cTnT), the biomarker of choice for the exclusion of myocardial injury. Hypothesis: Race- and gender-specific high-sensitivity cTnT (hs-cTnT) cutoff values will improve the detection of myocardial injury. Methods: Emergency Department encounters at the University of Chicago from June 2018 through April 2019 with at least 1 hs-cTnT value were included. Race- and gender-specific 99 th percentiles for hs-cTnT were determined for patients without a history of hypertension, heart failure, coronary artery disease, diabetes, or chronic kidney disease, and used as the threshold for a positive result. These threshold values were compared against manufacturer’s recommended gender-only values (male ≥ 22 ng/dL, female ≥ 14 ng/dL). Confusion matrices were used to calculate test characteristics. The presence of ischemic heart disease was determined by the corresponding International Statistical Classification of Diseases. Results: Among 10,934 included encounters, 89.9% were African American. The 99 th percentile values for African American were lower than for matched white counterparts. Race and gender specific cutoffs had higher specificity (83.1% vs 75.2%), greater positive predictive value (91.9% vs 90.7%), and lower false negative rates (16.9% vs. 24.8%) compared with traditional gender-only cutoff values. During the 10 months of data collection, race- and gender-specific cutoffs would have correctly identified 215 additional encounters as having ischemic heart disease, all of them African Americans. The net reclassification rate was +7.91%. Conclusions: Using race-specific, in addition to traditional gender-specific, hs-cTnT cutoff values resulted in higher specificity, greater positive predictive value, and lower false negative rates. Nearly 8% of patients with eventual diagnosis of ischemic heart disease would have been correctly reclassified using race- and gender-specific cutoffs. These findings suggest that race- and gender-specific cutoffs should be further explored.