Impact of the highly sensitive cardiac troponin t (hsTnT) assay on the triage of emergency department (ED) patients

Background. Troponin is recognised as the gold standard for diagnosing myocardial infarction. In our 600-beds university hospital, the 4th generation TnT assay was recently replaced by the hsTnT that improvesthe analytical sensitivity lowering the cut-off to 15 ng/L. Methods. During the three-month audit evaluating the impact of hsTnT implementation, we focused on patients presenting to the ED by comparing triage of hsTnT positive patients with that of TnT positive patients examined in the same period one year before. Results. In the two evaluated periods, the same number of tests (1472 vs. 1465 for TnT and hsTnT, respectively) was spread on a slightly different number of patients (from 1019 to 958, -6.0%).TnT and hsTnT gave 18.5% and 45.3% positive results (P<0.0001), with a 145% relative increase after hsTnT implementation. This corresponded to 196 and 434 positive examinations, respectively. After hsTnT implementation, the number of hospitalizedpatientswith positive troponin increased from 158 to 292 (+84.8%), even if the rate of admission in intensive and non intensive care departments was unchanged (P=0.108). 16 (8.5%) and 109 (26.6%) positive patients were discharged in the twoperiods.In the follow-up, only one discharged TnT patient returned to the ED, while 13 (12.9%) hsTnT patientswere readmitted, mainly for signs of cardiac involvement. Conclusions. The introduction of hsTnT markedly increased the number of positive examinations and following hospital admissions in ED population. However, about ¼ of hsTnT positive patients were discharged showing that triage decisions are not only based on the biomarker Results.