Variability Between Reagent Lots for High-Sensitivity Cardiac Troponin I May Affect Performance of Early Rule Out Strategies

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

“…[4][5][6] In practice, different lots of reagents for both hs-cTnI and hs-cTnT have already been observed to yield variation that exceeds 3 ng/L. 7,8 In addition, there are several interferences that affect hs-cTn measurements. 9,10 Together, this necessitates improved laboratory health services to aid physicians in evaluating patients with possible acute coronary syndrome.…”

“…Algorithms that use the lower limit of reporting, such as the limit of detection, for hs-cTn assays are approaches that pose a safety risk for patients, because this metric is not monitored by clinical laboratories and is subject to analytical bias, with wide variation on repeat measurements on different instruments and different lots of reagents; all of which may lead to patient misclassification. 4,[6][7][8]36 Just as important is that there is no standardization on reporting at the low end: in a 2018 quality survey, undetectable ranges were reported from clinical laboratories that ranged from less than 1 to less than 10 ng/L for the Abbott hs-cTnI assay and less than 3 to less than 13 ng/L for the Roche hs-cTnT assay. 37 In this regard, physicians using "undetectable concentrations" will misclassify patients depending on how the clinical laboratory reports their results, if they use results from hs-cTn testing alone.…”

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

“…In this regard, we have provided evidence of analytical issues that affect interpretation around and below 5 ng/L. 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.…”

Four Different High-Sensitivity Cardiac Troponin Assays With Important Analytical Performance Differences

“…Previously, we have illustrated that different reagent lots of cTn from the same manufacturer can yield widely different precision profiles, cautioning the use of small concentration changes to either rule in or rule out MI. 3 This was followed by additional studies illustrating the safety of using assayspecific concentration cutoffs that can be monitored in the clinical laboratory as opposed to using a low cTn concentration alone for early decision making. 4 In the present study, we assess the agreement and reproducibility of cTn results across 4 different hs-cTn assays: Siemens Dimension EXL hs-cTnI, Roche Cobas hs-cTnT, Siemens ADVIA Centaur hs-cTnI, and Abbott ARCHITECT hs-cTnI (i1000 and i2000 instruments) (for manufacturer listed analytical sensitivity, precision, 99th percentiles, see http://www.ifcc.org/media/477656/high-sensitivity-cardiactroponin-i-and-t-assay-analytical-characteristics-designatedby-manufacturer-v012019.pdf).…”