Clinical impact of a high-sensitivity troponin assay introduction on patients presenting to the emergency department

Objective: Biomarkers are a critical component in the investigation of patients with potential ischaemic heart disease. The proposed benefits of a high-sensitivity troponin (hs-Tn) assay include earlier diagnosis of myocardial infarction. However, the decreased specificity may adversely affect clinical practice. The present study aims to investigate the impact that the introduction of a hs-Tn assay had on patients presenting to the ED. Methods: A pre- and post-interventional analysis was performed on all patients presenting to the Royal Melbourne Hospital ED, and had a troponin, in the 12months before and after the introduction of the hs-Tn assay. The main outcome measures were ED length of stay, admission rates, proportion of patients undergoing interventional cardiac procedures and proportion diagnosed with myocardial infarction. Results: There were 6557 patients who had a conventional assay and 7335 patients who had a hs-Tn assay. The introduction of a hs-Tn assay was associated with an increased abnormal troponin rate (23.4% vs 28.1%, P<0.001). The median length of ED stay decreased by 9.1% (P<0.001). The proportion admitted to hospital increased (60.9% vs 65.9%, P<0.001); however, there was no difference in the proportion undergoing revascularisation or the proportion diagnosed with myocardial infarction. Conclusions: Although the introduction of a hs-Tn assay led to an increase in hospital admissions, the unchanged rate of cardiac procedures or final diagnoses of acute myocardial infarction and ischaemic heart disease suggests that the hs-Tn did not improve the detection of these conditions. It remains unclear whether there was a benefit admitting the additional cohort of patients.