Troponin T (Highly Sensitive)

CPT: 84484
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Synonyms

  • Cardiac Troponin T

Special Instructions

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.


Expected Turnaround Time

1 - 3 days


Related Information


Related Documents

For more information, please view the literature below.

High Sensitive Troponin T (hsTnT): A New 5th Generation Assay


Specimen Requirements


Specimen

Plasma (lithium-heparin), frozen


Volume

1 mL


Minimum Volume

0.8 mL (Note: This volume does not allow for repeat testing.)


Container

Green top (lithium-heparin) tube. Lithium heparin plasma tubes containing separating gel can be used.


Collection

Centrifuge and transfer separated heparin plasma to a plastic transport tube and label as Li-Heparin plasma. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.


Storage Instructions

Freeze.


Stability Requirements

Temperature

Period

Refrigerated

24 hours (stability provided by manufacturer or literature reference)

Frozen

12 months (stability provided by manufacturer or literature reference)

Freeze/thaw cycles

Stable x1 (stability provided by manufacturer or literature reference)


Causes for Rejection

Sample other than lithium heparin plasma


Test Details


Use

Immunoassay for the in vitro quantitative determination of cardiac troponin T (cTnT) in lithium heparin plasma. The immunoassay is intended to aid in the diagnosis of myocardial infarction.


Limitations

For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

The Universal Definition of AMI takes into consideration the ESC/ACC/AHA/WHF definition recommending the detection of a rise and/or fall of cardiac troponin in the clinical setting with at least one value above the 99th percentile upper reference limit.1,2 Due to the release kinetics of cardiac troponin T, an initial test result may not be definitive in diagnosing MI. Serial cardiac troponin measurements are suggested.

Troponins are released during the process of myocyte necrosis. While they are cardiac-specific, they are not specific for MI, and detectable levels may be seen in other disease states that involve the heart muscle (e.g. arrhythmia, acute aortic syndrome, acute heart failure, hypertensive crisis, myocarditis, pericarditis, pulmonary embolism and Takotsubo cardiomyopathy), so that ACC/ESC/AHA guidelines and the Universal Definition of MI recommend serial sampling with a rise or fall in troponin to distinguish between acute and chronic cTn elevations.

A number of factors other than AMI are associated with elevated values.3-9 Published clinical studies have shown elevations of cardiac troponin T in patients with myocardial injury, as seen in stable or unstable angina, heart failure, myocarditis, pulmonary embolism, pericarditis, arrhythmias, cardiac contusions, and cardiac transplants. Elevations are also notable in patients with rhabdomyolysis and polymyositis.

Samples showing visible signs of hemolysis may cause interference. Falsely depressed results are obtained when using samples with hemoglobin concentrations > 0.1 g/dL.

For assays using antibodies, the possibility exists for interference by heterophileantibodies in the patient’s sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures using immunoglobulin or immunoglobulin fragments may produce antibodies, e.g. HAMA, that interfere with immunoassays. Carefully evaluate the results of patients suspected ofhaving these antibodies.

In rare cases, interference due to extremely high titers of antibodies to analyte‐specificantibodies, streptavidin or ruthenium can occur. The reagent has been formulated to minimize this effect.

Samples should not be taken from patients receiving therapy with high biotin doses (i.e.> 5 mg/day) until at least 8 hours following the last biotin administration.


Methodology

Electrochemiluminescence immunoassay (ECLIA)


Reference Interval

See table.

Age

Male (ng/L)

Female (ng/L)

All

0–22

0–14


Additional Information

Troponin T (TnT) is a component of the contractile apparatus of the striated musculature. Although the function of TnT is the same in all striated muscles, the cardiac isoform of TnT originating exclusively from the myocardium clearly differs from skeletal muscle TnT. As a result of its high tissue‐specificity, cardiac troponin T (cTnT) is a cardio‐specific, highly sensitive marker for myocardial damage. Cardiac troponin T increases rapidly10 after acute myocardial infarction (AMI) and may persist up to 2 weeks thereafter.11,12 In contrast to ST‐elevation myocardial infarction (STEMI), the diagnosis of non‐ST elevation myocardial infarction (NSTEMI) relies heavily upon elevated cardiac troponin (cTn) concentrations in the appropriate clinical context. The Third Universal Definition of Myocardial Infarction (MI) has confirmed cTn as the biomarker of choice.13 Diagnosis of MI is made with acute changes in cTn concentrations with at least one serial sample above the 99th percentile upper reference limit (URL), taken together with evidence of myocardial ischemia (symptoms, electrocardiogram (ECG) changes or imaging results). Various guidelines and publications recommend the optimal imprecision (coefficient of variation) of cTn assays at the 99th percentile upper reference limit be less than or equal to 10%.10,13-17

Several guidelines and research activities recognize that improved analytical sensitivity of cTn assays during the last several years has allowed for detection of other etiologies. Chronic cTn elevations can be detected in clinically stable patients such as patients with ischemic or non‐ischemic heart failure,18,19 patients with different forms of cardiomyopathy,20 renal failure,21-27 sepsis,28 and diabetes.29 Elevated concentrations of cTn can also occur in other clinical conditions such as myocarditis,30 heart contusion,31 pulmonary embolism,32 and drug‐induced cardiotoxicity.33

To distinguish between acute and chronic cTn elevations, the Universal Definition of MI stresses the need for serial sampling to observe a rise and/or fall of cTn above the 99th percentile upper reference limit consistent with the clinical assessment, including ischemic symptoms and electrocardiographic changes.13 Troponin elevations may persist for up to 14 days or occasionally longer.13 Other diagnostic tests such asNT‐proBNP and CRP can complement the diagnostic and prognostic information of cTnT in different indications.

By current universal definition of the disease (AMI), the 99th percentile URL should be used as a diagnostic cutoff of AMI,13 and is endorsed by major local guidelines.10,16,34 Higher cutoffs produce higher estimates of clinical specificity and positive predictive value (PPV), but tend to underestimate clinical sensitivity and negative predictive value (NPV).35 When switching to the Elecsys Troponin T Gen 5 STAT assay, users should be aware that the guideline compliant test using the 99th percentile URL as a diagnostic cutoff, can lead to a relative increase in the diagnosis of acute MIs compared to contemporary assays using other, often higher cutoffs.10,36-38


Footnotes

1. Mendis S, Thygesen K, Kuulasmaa K, et al. World Health Organization definition of myocardial infarction: 2008-09 revision. Int J Epidemiol. 2011 Feb;40(1):139-146.20926369
2. Alpert JS, Thygesen K, Antman E, Bassand JP. Myocardial infarction redefined - a consensus document of the Joint European Society of Cardiology/American College of Cardiology committee for the redefinition of myocardial infarction. J Am Coll Cardiol. 2000 Sep(3);36:959-969.10987628
3. Kobayashi S, Tanaka M, Tamura N, Hashimoto H, Hirose S. Serum cardiac troponin T in polymyositis/dermatomyositis. Lancet. 1992 Sep 19;340(8821):726.1355820
4. Mair J, Dienstl F, Puschendorf B. Cardiac troponin T in the diagnosis of myocardial injury. Crit Rev Clin Lab Sci. 1992;29(1):31-57.1388708
5. Carrier M, Solymoss BC, Cartier R, Leclerc Y, Pelletier LC. Cardiac Troponin T and Creatine Kinase MB Isoenzyme as Biochemical Markers of Ischemia after Heart Preservation and Transplantation. J Heart Lung Transplant. 1994 Jul-Aug;13(4):696-700.7947887
6. Löfberg M, Tähtelä R, Härkönen M, Somer H. Myosin heavy-chain fragments and cardiac troponins in the serum in rhabdomyolysis. Diagnostic Specificity of New Biochemical Markers. Arch Neurol. 1995 Dec;52(12):1210-1214.7492296
7. Anderson JR, Hossein-Nia M, Brown P, Holt DW, Murday A. Donor cardiac troponin T predicts subsequent inotrope requirements following cardiac transplantation. Transplantation. 1994 Nov 15;58(9):1056-1057.7974735
8. Franz WM, Remppis A, Kandolf R, Klüber W, Katus HA. Serum troponin T: diagnostic marker for acute myocarditis. Clin Chem. 1996 Feb;42(2):340-341.8595741
9. Mair P, Mair J, Koller J, Wieser C, Artner-Dworzak E, Puschendorf B. Cardiac troponin T in the diagnosis of heart contusion. Lancet. 1991 Sep 14;338(8768):693.1679489
10. Roffi M, Patrono C, Collet JP, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndrome in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J. 2016 Jan 14;37(3):267-315.26320110
11. Katus HA, Remppis A, Looser S, Hallermeier K, Scheffold T, Klüber W. Enzyme linked immunoassay of cardiac troponin T for the detection of acute myocardial infarction in patients. J Mol Cell Cardiol. 1989 Dec;21(12):1349-1353.2632816
12. Katus HA, Scheffold T, Remppis A, Zehlein J. Proteins of the troponin complex. Laboratory Medicine. 1992 May 1;23(5):311-317. Available at https://doi.org/10.1093/labmed/23.5.311. Accessed January 2021.
13. Thygesen K, Alpert JS, Jaffe AS, et al. Third universal definition of myocardial infarction. J Am Coll Cardiol. 2012 Oct 16;60(16):1581-1598.22958960
14. Reichlin T, Hochholzer W, Bassetti S, et al. Early diagnosis of myocardial infarction with sensitive cardiac troponin assays. N Engl J Med. 2009 Aug 27;361(9):858-867.19710484
15. Giannitsis E, Becker M, Kurz K, Hess G, Zdunek D, Katus HA. High-sensitivity cardiac troponin T for early prediction of evolving non-ST-segment elevation myocardial infarction in patients with suspected acute coronary syndrome and negative troponin results on admission. Clin Chem. 2010 Apr;56(4):642-650.20167697
16. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC Guideline for the management of patients with non-ST-elevation acute coronary syndromes: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014 Dec 23;130:2354-2394.25249586
17. Apple FS, Jaffe AS, Collinson P, et al. IFCC educational materials on selected analytical and clinical applications of high sensitivity cardiac troponin assays. Clin Biochem. 2015 Mar;48(4-5):201-203.25204966
18. Masson S, Anand I, Favero C, et al. Serial measurement of cardiac troponin T using a highly sensitive assay in patients with chronic heart failure: data from 2 large randomized clinical trials. Circulation. 2012 Jan 17;125(2):280-288.22139751
19. Jeremias A, Kleiman NS, Nassif D, et al. Prevalence and prognostic significance of preprocedural cardiac troponin elevation among patients with stable coronary artery disease undergoing percutaneous coronary intervention. Circulation. 2008 Aug 5;118(6):632-638.18645057
20. Cramer G, Bakker J, Gommans F, et al. Relation of highly sensitive cardiac troponin T in hypertropic cardiomyopathy to left ventricular mass and cardiovascular risk. Am J Cardiol. 2014 Apr 1;113(7):1240-1245.24513467
21. McGill D, Talaulikar G, Potter JM, et al. Over time, high-sensitivity TnT replaces NT-proBNP as the most powerful predictor of death in patients with dialysis-dependent chronic renal failure. Clin Chim Acta. 2010 Jul 4;411(13-14):936-939.20298685
22. Artunc F, Mueller C, Breidthardt T, et al. Sensitive troponins – which suits better for hemodialysis patients? Associated factors and prediction of mortality. PLoS One. 2012;7(10):e47610.23077650
23. Apple FS, Wu AH. Myocardial infarction redefined: Role of cardiac troponin testing. Clin Chem. 2001 Mar;47(3):377-379.11238285
24. Wolley M, Steward R, Curry E, Davidson J, White H, Pilmore H. Variation in and prognostic importance of troponin T measured using a high-sensitivity assay in clinically stable haemodialysis patients. Clin Kidney J. 2013 Aug;6(4):402-409.27293568
25. Honneger Bloch S, Semple D, Sidhu K, Stewart R, Pilmore H. Prognostic value and long-term variation of high sensitivity troponin T in clinically stable haemodialysis patients. N Z Med J. 2014 Sep 12;127(1402):97-109.25228425
26. Twerenbold R, Wildi K, Jaeger C, et al. Optimal cutoff levels of more sensitive cardiac troponin assays for the early diagnosis of myocardial infarction in patients with renal dysfunction. Circulaton. 2015 Jun 9;131(23):2041-2050.25948542
27. Dubin RF, Li Y, He J, et al. Predictors of high sensitivity cardiac troponin T in chronic kidney disease patients: a cross-sectional study in the chronica renal insufficiency cohort (CRIC). BMC Nephrol. 2013 Oct 22;14:229.24148285
28. Landesberg G, Jaffe AS, Gilon D, et al. Troponin elevation in severe sepsis and septic shock: the role of left ventricular diastolic dysfunction and right ventricular dilatation*. Crit Care Med. 2014 Apr;42(4):790-800.24365861
29. Everett BM, Brooks MM, Vlachos HE, et al. Troponin and cardiac events in stable ischemic heart disease and diabetes. N Engl J Med. 2015 Aug 13;373(7):610-620.26267622
30. Lewandrowski KB. Special topics: cardiac markers in myocarditis: cardiac transplant rejection and conditions other than acute coronary syndrome. Clin Lab Med. 2014 Mar;34(1):129-135.24507792
31. Swaanenburg JC, Klaase JM, DeJongste M, Zimmerman KW, ten Duis HJ. Troponin I, troponin T, CK-MB-activity and CK-MB mass as markers for the detection of myocardial contusion in patients who experienced blunt trauma. Clin Chim Acta. 1998 Apr 27;272(2):171-181.9641358
32. Bajaj A, Saleeb M, Rathor P, Sehgal V, Kabak B, Hosur S. Prognostic value of troponins in acute nonmassive pulmonary embolism. A meta-analysis. Heart Lung. 2015 Jul-Aug;44(4):327-334.25976228
33. Newby LK, Rodriguez I, Finkle J, et al. Troponin measurements during drug development - considerations for monitoring and management of potential cardiotoxicity: an educational collaboration among the Cardiac Safety Research Consortium, the Duke Clinical Research Institute, and the US Food and Drug Administration. Am Heart J. 2011 Jul;162(1):64-73.21742091
34. National Institute for Health and Care Excellence. Myocardial infarction (acute): Early rule out using high-sensitivity troponin tests (Elecsys Troponin T high-sensitive, ARCHITECT STAT High Sensitive Troponin-I and AccuTnl+3 assays). National Institute for Health and Care Excellence (NICE). Diagnostics guidance [DG15]. Oct 2014. Available at www.nice.org.uk/dg15[NICE guideline]. Accessed January 2021.
35. Lipinski MJ, Baker NC, Escárcega RO, et al. Comparison of conventional and high-sensitivity troponin in patients with chest pain: a collaborative meta-analysis. Am Heart J. 2015 Jan;169(1):6-16 e6.25497242
36. Sethi A, Bajai A, Malhortra G, Arora RR, Khosla S. Diagnostic accuracy of sensitive or high-sensitive troponin on presentation for myocardial infarction: a meta-analysis and systematic review. Vasc Health Risk Manag. 2014 Jul 21;10:435-450.25092986
37. Reichlin T, Twerenbold R, Reiter M, et al. Introduction of High sensitivity Troponin Assays: Impact on Myocardial Infarction Incidence and Prognosis. Am J Med. 2012 Dec;125(12):1205-1213.e1.23164485
38. Giannitis E, Kurz K, Hallermayer K, Jarausch J, Jaffe AS, Katas HA. Analytical Validation of a High-Sensitivity Cardiac Troponin T Assay. Clin Chem. 2010 Feb;56(2):254-261.19959623

References

Gillis JM, Dunselman P, Jarausch J, de Jong N, Cobbaert CM. Preanalytical storage does not affect 99th percentile cardiac Troponin T concentrations measured with a high-sensitive assay. Clin Chem. 2013 Feb;59(2):442-443.23220225
Elecsys Troponin T Gen 5 STAT [package insert]. Indianapolis, IN: Roche Diagnostics. 2017-03, V 1.0.

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
140150 Troponin T 89576-3 140164 Troponin T(Highly Sensitive) ng/L 67151-1

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