High‐Sensitivity Cardiac Troponin T Compared With Standard Troponin T Testing on Emergency Department Admission: How Much Does It Add in Everyday Clinical Practice?

BACKGROUND: We compared high-sensitivity cardiac troponin T (hs-cTnT) and standard cTnT for acute myocardial infarction (AMI) diagnosis in everyday clinical practice of an emergency department (ED). METHODS AND RESULTS: cTnT was measured in 2384 consecutive patients (60 ± 21 years, 52% female) on ED admission. Readmissions to the ED (n=720) and mortality (n=101) were followed for an average period of 239 ± 49 days. There were 53 AMIs (delay, 1 to 96 hours; median, 3 hours), 440 chest pain patients, 286 dyspnea patients, 785 acute or chronic cardiac diseases, and 540 neurological diseases, with the remaining having various internal diseases. The diagnostic performances of hs- and standard cTnT were comparable for AMI diagnosis (area under receiver operating characteristics curves [ROC AUC], 0.91 ± 0.02 versus 0.90 ± 0.03; P=0.31). Using the 99th-percentile cutoff, the sensitivities and specificities for AMI in the whole population were 91% and 74% for hs-cTnT and 89% and 80% for standard cTnT. hs-cTnT detected significantly more patients with cardiac diseases (ROC AUC, 0.77 ± 0.01 versus 0.67 ± 0.01; P<0.001). hs-cTnT and standard cTnT were significant predictors of ED readmissions but not of mortality, but both were not independent predictors of ED readmissions or the combined end point of readmission or mortality in binary logistic regression analysis. CONCLUSIONS: In unselected ED patients the diagnostic performances of hs-cTnT and standard cTnT for AMI diagnosis did not differ significantly. hs-cTnT detected significantly more cardiac diseases. hs-cTnT and standard cTnT were not independent predictors of ED readmissions and mortality from all causes.