Clinical chemistry score versus high-sensitivity cardiac troponin I and T tests alone to identify patients at low or high risk for myocardial infarction or death at presentation to the emergency department

Abstract

T he use of a single high-sensitivity cardiac troponin (hscTn) test concentration on presentation to the emergency department has been proposed for triage and early decision-making in patients with suspected acute coronary syndrome.1-3 However, a single low concentration result for hscTn for identifying patients at low risk in the emergency department may misclassify patients, because an analytical variation of ± 3 ng/L for the hs-cTn assays at the low analytical range is RESEARCH Clinical chemistry score versus high-sensitivity cardiac troponin I and T tests alone to identify patients at low or high risk for myocardial infarction or death at presentation to the emergency department ABSTRACT BACKGROUND: Testing for high-sensitivity cardiac troponin (hs-cTn) may assist triage and clinical decision-making in patients presenting to the emergency department with symptoms of acute coronary syndrome; however, this could result in the misclassification of risk because of analytical variation or laboratory error. We sought to evaluate a new laboratorybased risk-stratification tool that incorporates tests for hs-cTn, glucose level and estimated glomerular filtration rate to identify patients at risk of myocardial infarction or death when presenting to the emergency department.

High-Sensitivity Cardiac Troponin I vs a Clinical Chemistry Score for Predicting All-Cause Mortality in an Emergency Department Population

“…The cutoffs used for the Abbott Laboratories hs-cTnI assay were < 5 ng/L, 5 to 26 ng/L, and > 26 ng/L, as previously used in patients with suspected ACS. 1 , 2 , 3 , 14 The simple laboratory algorithm or CCS has been published in both a multicenter Canadian study and an international study. 14 , 18 Results from glucose, eGFR, and hs-cTnI are converted into an ordinal scale, with the sum ranging from 0 (low risk) to 5 (high risk).…”

“… 1 , 2 , 3 , 14 The simple laboratory algorithm or CCS has been published in both a multicenter Canadian study and an international study. 14 , 18 Results from glucose, eGFR, and hs-cTnI are converted into an ordinal scale, with the sum ranging from 0 (low risk) to 5 (high risk). 14 , 18 The scores are generated as follows: glucose < 5.6 mmol/L = 0 points or ≥ 5.6 mmol/L = 1 point; eGFR ≥ 90 mL/min/1.73 m 2 = 0 points or < 90 mL/min/1.73 m 2 = 1 point; hs-cTnI < 4 ng/L = 0 points or 4-14 ng/L = 1 point or 15-30 ng/L = 2 points or > 30 ng/L = 3 points.…”

“… 14 , 18 Results from glucose, eGFR, and hs-cTnI are converted into an ordinal scale, with the sum ranging from 0 (low risk) to 5 (high risk). 14 , 18 The scores are generated as follows: glucose < 5.6 mmol/L = 0 points or ≥ 5.6 mmol/L = 1 point; eGFR ≥ 90 mL/min/1.73 m 2 = 0 points or < 90 mL/min/1.73 m 2 = 1 point; hs-cTnI < 4 ng/L = 0 points or 4-14 ng/L = 1 point or 15-30 ng/L = 2 points or > 30 ng/L = 3 points. 14 , 18 The CCS was calculated by the sum of the points from glucose, eGFR, and hs-cTnI.…”

“… 8 , 9 , 10 , 11 , 12 Laboratory recommendations on appropriate monitoring of the hs-cTnI assays will help mitigate some of these issues; 13 however, what has not been evaluated thoroughly is the impact of a low hs-cTnI result for risk stratification in a general ED population in North America. To address this gap, our goal was to compare Abbott hs-cTnI published cutoffs (eg, 5 ng/L and the overall 99th percentile of 26 ng/L) alone vs a simple laboratory algorithm (ie, Clinical Chemistry Score [CCS]) 14 at presentation in a general ED population to determine low- and high-risk patients for subsequent all-cause death.…”

Measurement of High-Sensitivity Cardiac Troponin in Pulmonary Embolism: Useful Test or a Clinical Distraction

“…This will lead the way to development and validation of updated risk stratification models, incorporating efficient laboratory biomarkers such as hs-cTn immunoassays with other laboratory and clinical variables for assessing patients with possible acute coronary syndrome (ACS) in the emergency setting. 6,60 To that end, interpretation of hs-cTnI may need to be revisited. Present recommendations suggest utilizing sex-specific 99th percentiles for identification of myocardial injury.…”