Analytical and Clinical Validation of a Point-of-Care Cardiac Troponin T Test with an Improved Detection Limit

Objective: The purpose of this study was to determine the predictive value of routine prehospital point-of-care cardiac troponin T measurement for diagnosis and risk stratification of patients with suspected acute myocardial infarction. Methods and results: All prehospital emergency medical service vehicles in the Central Denmark Region were equipped with a point-of-care cardiac troponin T device (Roche Cobas h232) for routine use in all patients with a suspected acute myocardial infarction. During the study period, 1 June 2012–30 November 2015, prehospital point-of-care cardiac troponin T measurements were performed in a total of 19,615 cases seen by the emergency medical service and 18,712 point-of-care cardiac troponin T measurements in 15,781 individuals were matched with an admission. A final diagnosis of acute myocardial infarction was confirmed in 2187 cases and a total of 2150 point-of-care cardiac troponin T measurements (11.0%) had a value ≥50 ng/l, including 966 with acute myocardial infarction (sensitivity: 44.2%, specificity: 92.8%). Patients presenting with a prehospital point-of-care cardiac troponin T value ≥50 ng/l had a one-year mortality of 24% compared with 4.8% in those with values <50 ng/l, log-rank: p<0.001. The following variables showed the strongest association with mortality in multivariable analysis: point-of-care cardiac troponin T≥50 ng/l (hazard ratio 2.10, 95% confidence interval: 1.90–2.33), congestive heart failure (hazard ratio 1.93, 95% confidence interval: 1.74–2.14), diabetes mellitus (hazard ratio 1.42, 95% confidence interval: 1.27–1.59) and age, one-year increase (hazard ratio 1.08, 95% confidence interval: 1.08–1.09). Conclusions: Patients with suspected acute myocardial infarction and a prehospital point-of-care cardiac troponin T ≥50 ng/l have a poor prognosis irrespective of the final diagnosis. Routine troponin measurement in the prehospital setting has a high predictive value and can be used to identify high-risk patients even before hospital arrival so that they may be re-routed directly for advanced care at an invasive centre.

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Three-month outcome of patients with suspected acute coronary syndrome using point-of-care cardiac troponin-T testing compared with laboratory-based cardiac troponin-T testing: a randomised trial

Emergency Medicine Journal ◽

10.1136/emermed-2014-203958 ◽

2014 ◽

Vol 32 (8) ◽

pp. 601-607 ◽

Cited By ~ 8

Author(s):

Stephen Edward Asha ◽

Andrew Cooke ◽

Elizabeth Walter ◽

James Weaver

Keyword(s):

Acute Coronary Syndrome ◽

Cardiac Troponin ◽

Troponin T ◽

Point Of Care ◽

Randomised Trial ◽

Cardiac Troponin T ◽

Coronary Syndrome

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Reference limits of high-sensitive cardiac troponin T indirectly estimated by a new approach applying data mining. A special example for measurands with a relatively high percentage of values at or below the detection limit

LaboratoriumsMedizin ◽

10.1515/labmed-2020-0063 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Rainer Haeckel ◽

Werner Wosniok ◽

Antje Torge ◽

Ralf Junker ◽

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Keyword(s):

Detection Limit ◽

Cardiac Troponin ◽

Troponin T ◽

Present Report ◽

Age Groups ◽

Specific Reference ◽

Cardiac Troponin T ◽

Decision Limit ◽

Reference Limits ◽

Age And Sex

AbstractA new model for the indirect estimation of reference limits (RLs) has been proposed recently and was coined TMC approach (truncated minimum chi-square estimation) which can be performed with R statistic. A spline function is applied to the RLs to get a continuous function if age is graphically presented vs. the RLs avoiding artificial “jumps” between different age groups. Most indirect models assume a power normal distribution and fail if this assumption is not fulfilled as e.g. if a relatively high percentage of measured values is below the detection limit and the data are distributed extremely skewed. This problem is handled by the TMC model. High-sensitive cardiac troponin T (hs cTnT) was chosen as an example. The hs cTnT concentration in serum or plasma is well accepted as a valuable marker in the diagnosis of acute myocardial infarction. Currently, the 99th percentile derived from a “healthy” subpopulation is the decision limit recommended by consensus groups. However, this decision limit is questioned by several authors for many reasons. In the present report, the 97.5th and the 99th percentile limits were reinvestigated by the TMC model with different subpopulations stratified according to age and sex and were finally compared to presently recommended decision limits. In summary, the generally recommended 99th percentile as a fixed decision limit should be reconsidered. It is suggested to apply more specific reference limits stratified for age and sex instead of a fixed decision limit.

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