Using the clinical chemistry score in the emergency department to detect adverse cardiac events: a diagnostic accuracy study

Abstract

vidence and guidelines have indicated that an undetectable or low concentration of high-sensitivity cardiac troponin (hs-cTn) at emergency department (ED) presentation may be a suitable criterion in certain patients for ruling out myocardial infarction (MI) and possibly discharging patients home. [1][2][3][4] The basis for this is the high clinical sensitivity and negative predictive value (NPV) that can be attained when an hs-cTn cut-off close to 5 ng/L is used. 2,3,5,6 However, the usefulness of an undetectable or low hs-cTn concentration in ruling out MI does not necessarily mean that it can also be used to predict whether a patient is at low risk for a subsequent cardiovascular event.An international survey of ED physicians indicated that an acceptable miss rate of major adverse cardiac events (MACE) within 30 days would be 1% or less. 7 Accordingly, the sensitivity required for MACE at 30 days should be at least 99% to achieve this threshold and to allow discharge and cessation of Using the clinical chemistry score in the emergency department to detect adverse cardiac events: a diagnostic accuracy study

Acute Phase Response and Non-Reproducible Elevated Concentrations with a High-Sensitivity Cardiac Troponin I Assay

“…Importantly, publications have also documented the clinical performance of the Ortho hs-cTnI assay in patients with symptoms suggestive of ACS [ 8 , 9 , 10 , 11 , 12 , 13 ]. Previous estimates of myocardial injury in patients with ACS symptoms are similar between Abbott hs-cTnI (19.7%) and Ortho hs-cTnI (20.8%) [ 18 ] with data presented here further suggesting 1%–2% false positives with Ortho hs-cTnI when re-measured with Roche hs-cTnT.…”

“…Cohort 6 was an ED population selected based on symptoms suggestive of ACS, with details on this population previously reported [ 4 , 7 , 9 , 11 , 12 ]. For this analysis, patients ( n = 1058) whom had myocardial injury detected by Ortho hs-cTnI at presentation ( n = 215) were also evaluated with Roche hs-cTnT (another diagnostic method targeting a different protein) to assess the difference in positivity and 30-day major adverse cardiac events (MACE which included myocardial infarction, unstable angina, death) between these biomarkers [ 11 ].…”

“…Cohort 6 was an ED population selected based on symptoms suggestive of ACS, with details on this population previously reported [ 4 , 7 , 9 , 11 , 12 ]. For this analysis, patients ( n = 1058) whom had myocardial injury detected by Ortho hs-cTnI at presentation ( n = 215) were also evaluated with Roche hs-cTnT (another diagnostic method targeting a different protein) to assess the difference in positivity and 30-day major adverse cardiac events (MACE which included myocardial infarction, unstable angina, death) between these biomarkers [ 11 ]. The hypothesis under investigation here was that ED patients with symptoms of ACS with injury by the Ortho hs-cTnI assay would also be classified with injury with Roche hs-cTnT, confirming the previous results of the accurate performance of the Ortho hs-cTnI assay in patients with ACS symptoms [ 8 , 9 , 11 , 12 , 13 ].…”

“…The Ortho VITROS XT 7600 analyzer using dry chemistry slide technology and reflection for detection was used for urea (urease colorimetric method with CVs < 2%), creatinine (enzymatic two-point rate method using creatinine amidohydrolase with CVs < 3%), and CRP (fixed-point immuno-rate method using phosphorylcholine-linked capture beads with CV target < 6.7%). The eGFR was calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation as previously described [ 11 ].…”

“…Diagnostic companies have, therefore, invested resources not only in the development of hs-cTn assays but also in clinical and analytical studies. The latest hs-cTnI assay to obtain regulatory approval (in 2019) outside the United States which is available on large, integrated core laboratory instruments (i.e., chemistry and immunoassay testing) is the Ortho Clinical Diagnostics hs-cTnI assay, with both clinical and analytical performance data recently published [ 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. However, data on assay performance outside carefully conducted clinical and analytical studies are also important.…”