Test Code LAB5996 High Sensitivity Troponin I Series, plasma
Performing Laboratory
Barnes-Jewish Hospital Laboratory
Methodology
Chemiluminescent microparticle immunoassay
Testing Algorithm:
If troponin delta value is ≥ 20 ng/L or 20%, LAB18 Lipid Panel will be performed for the first positive value, at an additional charge. Subsequent positive values do not reflex to a lipid panel.
Note: Lipid Panel is performed per recommendation of the National Cholesterol Education Panel, 2004.
Literature Reference:
Package insert: STAT High Sensitivity Troponin-I reagent. Abbott Laboratories, Diagnostic Division, Abbott Park, IL
Specimen Requirements
Specimen Type: Plasma
Container/Tube: Lavender top (K2 EDTA)
Specimen Volume: Full tube
Additional Information: Troponin I concentrations increase in blood ~2 hours after myocardial infarction and remain elevated for up to 8 days. Patients with chronic comorbidities that cause non-ischemic cardiac injury (e.g., cardiomyopathy, end-stage renal failure, etc.) will often have elevated high sensitivity troponin concentrations. According to the 4th Universal Definition of Myocardial Infarction, the following criteria must be met for a myocardial infarction to be present: “clinical evidence of acute myocardial ischemia and with detection of a rise and/or fall of troponin values with at least one value above the 99th percentile URL.” Therefore, serial troponin testing is essential for diagnosing acute MI, particularly when index troponin concentrations are above the sex specific 99th% upper reference limit but < 100 ng/L. Significant changes (delta) in troponin concentrations can be found in the acute chest pain algorithm adopted by WU lab medicine, cardiology and emergency medicine at https://bjhlab.testcatalog.org/show/hsTrop-1.
Literature Reference:
Journal of the American college of Cardiology 2019;73:1059-1077.
Day(s) Test Set Up
Monday through Sunday
Turnaround Time:
STAT: 1 hour after receipt in laboratory
Routine: not available
Reference Values
Male: < 35 ng/L
Female: < 17 ng/L
Critical result (automatic call-back): > 200 ng/L or Significant Delta for 2, 4, or 6 Hr sample
Note: Initial critical result is called. Subsequent values within 48 hours are not called but these values will be modified with comment “Previous critical result noted".
Result Note: Delta calculations and Interpretive results will be reported as See Comment with the comment: "Inappropriate collection time to report a delta" when: a 2 hour sample is collected at </= 90 minutes or > 150 minutes after baseline, or a 4 hour sample is collected at </= 3 hours or > 5 hours after baseline, or a 6 hour sample is collected at </= 5 hours or > 7 hours after baseline.
Literature References:
Thygesen K, Alpect JS, Jaffe AS, et.al. Fourth Universal Definition of Myocardial Infarction. J Am Coll Cardiol 2018;72:2231-2264.
Specimen Transport Temperature
Ambient
Additional Information
For BJH Laboratory Use Only
Alternate Tube(s):
None
Laboratory Processing Instructions:
Test performed in BJH Core Lab. Processed by automated line for delivery to the Architect off-line analyzer. Completed specimens are stored refrigerated for 5 days.
Test Classifications and CPT Coding
84484-Troponin I
80061-Lipid panel (if appropriate)
Specials Instructions
See Analyte Stability Chart under General Information for a complete list.
LOINC Code Information
Name |
LOINC Code |
Troponin I High Sensitivity, Plasma |
89579-7 |