Use of a high-sensitivity troponin T assay in the assessment and disposition of patients attending a tertiary Australian emergency department: a cross-sectional pilot study.

OBJECTIVE

We examined the disposition and outcomes of patients presenting to the ED with symptoms suggestive of acute coronary syndrome undergoing measurement of troponin T using a highly sensitive assay.

METHODS

Troponin T (TnT) was measured in 204 consecutive patients (mean age = 65 [±18] years, 55% men) presenting to the ED with symptoms suggestive of acute coronary syndrome.

RESULTS

Ninety-four patients predominantly had chest pain, 34 had dyspnoea and the remainder had various symptoms. Overall, 96 patients had TnT >14 ng/L (upper reference limit), of whom 31 were admitted to the cardiology service (26 had final cardiac diagnosis [five ST-elevation MI, 10 non-ST-elevation MI, one unstable angina and 10 other cardiac]). Among these 96 patients, 41 had chronic kidney disease, 17 had heart failure and seven had sepsis. At 30 days, death rates among patients who had TnT >14 ng/L with non-cardiac diagnoses and in patients who had TnT >14 ng/L with a cardiac diagnosis were 6.6% and 2.9% (P = 0.652); no death and/or MI occurred in patients with normal TnT levels. At late follow up (median 6.8 months) that was obtained in 189 (93% of 204) patients, four had MI and 14 died (three cardiac deaths).

CONCLUSIONS

Despite high-sensitivity TnT assay having a high sensitivity and specificity for myocardial necrosis, the majority of unselected consecutive patients attending ED in whom TnT levels were elevated did not have an acute coronary syndrome. Our pilot study suggests that a larger study is needed to provide evidence to modify management algorithms.