Troponin: A risk‐defining biomarker for emergency department physicians

Abstract

In this issue of Emergency Medicine Australasia Jairam et al. report their findings on the clinical impact of using a new high-sensitivity troponin assay in a tertiary teaching hospital in New Zealand. Troponin testing was duplicated in patients in whom troponin (Tn) was ordered as part of their clinical management, using two assays: a 4th generation troponin T (cTnT) and the high-sensitivity TnT (hsTnT) assays. The authors aimed to identify changes in the positivity rate by using the high-sensitivity assay, and to characterize those patients in whom the hsTnT was positive, but the contemporary TnT was negative (the ‘new positive’ group). They described a significant increase in the numbers of patients with elevated troponin levels using the hsTnT assay (the ‘new positive’ group), but found that the diagnoses were often not AMI. Few biomarkers in clinical use are as important as troponin, and yet so complex. Troponin levels continue to define patient populations, and determine the management of those patients presenting with a possible acute coronary syndrome. Recommended management guidelines for admission and monitoring practices, and the use of an invasive strategy exist for those found to be troponin positive; i.e. those with a non-ST-elevation acute myocardial infarction (NSTEMI). Improvements in the sensitivity and precision of troponin assays have occurred since the assay was first developed. This evolution has confused and challenged clinicians, and there has been limited consideration of the broad implications of this change to individual patients, the clinician and health services in general.