Analytical Validation of a High-Sensitivity Cardiac Troponin T Assay
ABSTRACT We report the development of a novel high-sensitivity cardiac troponin T (hs-cTnT) assay, a modification of the Roche fourth-generation cTnT assay, and validation of the analytical performance of this assay.
Validation included testing of analytical sensitivity, specificity, interferences, and precision. We established the 99th percentile cutoff from healthy reference populations (n = 616). In addition, we studied differences in time to a positive result when using serial measurements of hs-cTnT vs cTnT in patients with a confirmed diagnosis of non-ST elevation myocardial infarction (non-STEMI).
The hs-cTnT assay had an analytical range from 3 to 10 000 ng/L. At the 99th percentile value of 13.5 ng/L, the CV was 9% using the Elecsys 2010 analyzer. The assay was specific for cTnT without interferences from human cTnI or cTnC, skeletal muscle TnT, or hemoglobin concentrations up to 1000 mg/L, above which falsely lower values would be expected. When the assay was evaluated clinically, a hs-cTnT higher than the 99th percentile concentration identified a significantly higher number of patients with non-STEMI on presentation (45 vs 20 patients, P = 0.0004) compared with cTnT, and a final diagnosis of non-STEMI was made in 9 additional patients (55 vs 46 patients, P = 0.23) after serial sampling. Time to diagnosis was significantly shorter using hs-cTnT compared with cTnT [mean 71.5 (SD 108.7) min vs 246.9 (82.0) min, respectively; P < 0.01].
The analytical performance of hs-cTnT complies with the ESC-ACCF-AHA-WHF Global Task Force recommendations for use in the diagnosis of MI.
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ABSTRACT: Cardiac troponin is used as a marker for all types of myocardial infarction. Assays for high-sensitivity troponin T and I were performed before, immediately and 24hours after a 40km bicycle ride in two middle aged individuals. There was a significant increase in cardiac troponin immediately after exercise in both individuals. This was accompanied by a return to baseline levels within 24hours. A CT angiogram was normal in one while the other had a significant occlusion in the mid right coronary artery. After a stent placement, in this latter individual, there was no major increase in troponin after a second bicycle ride. Using high sensitivity assays, at least one of these two subjects may have suffered a type 2 myocardial infarction had the increases in hs-cTnI were accompanied by other acceptable evidence of myocardial ischemia (symptoms, ECG, etc.).. Copyright © 2015. Published by Elsevier B.V.Clinica chimica acta; international journal of clinical chemistry 04/2015; 446. DOI:10.1016/j.cca.2015.04.002 · 2.76 Impact Factor
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ABSTRACT: Despite several publications on the analytical performance of high-sensitivity cardiac troponin (hs-cTn) assays, there has been little information on how laboratories should validate and implement these assays into clinical service. Our study provides a practical approach for the validation and implementation of a hs-cTn assay across a large North American City.04/2015; 1:28-34. DOI:10.1016/j.plabm.2015.02.001
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ABSTRACT: Adult congenital heart disease (ACHD) patients are at risk of late complications including arrhythmias, heart failure and sudden death. High-sensitive troponin-T (hs-TnT) is the standard for diagnosing acute coronary syndrome, but is also associated with cardiac function and prognosis in other cardiac diseases. We aimed to describe hs-TnT level in ACHD patients, and determine its relationship with cardiac function and other biomarkers. Consecutive ACHD patients, visiting the outpatient clinic, underwent echocardiography, exercise testing and venipuncture on the same day. In total 587 patients were included (median age 33 [IQR 25-41] years, 58% male, 90% NYHA class I). hs-TnT was above the detection limit of 5ng/L in 241 patients (41%), of whom 47 (8%) had hs-TnT levels above the 99th percentile of normal of 14ng/L. hs-TnT levels were highest in patients with a systemic RV or pulmonary hypertension. Patients with normal or non-detectable hs-TnT were younger (32 [IQR 24-40] years) than patient with elevated hs-TnT (42 [IQR 36-60] years, p<0.001). The prevalence of hs-TnT ≥14ng/L was higher in patients with NYHA ≥II (36%, p<0.001), systemic systolic dysfunction (38%, p<0.001), non-sinus rhythm (43%, p<0.001) and elevated pulmonary pressures (39%, p<0.001). hs-TnT was correlated with NT-proBNP (r=0.400, p<0.001). hs-TnT above the 99th percentile of normal is observed in a non-trivial portion of stable ACHD patients, especially in those with a systemic RV or elevated pulmonary pressures. Since this biomarker of myocardial damage is related to NT-proBNP and ventricular function, its potential predictive value in ACHD patients seems promising and further investigation of underlying mechanisms is warranted. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.International Journal of Cardiology 04/2015; 184. DOI:10.1016/j.ijcard.2015.02.027 · 6.18 Impact Factor