Troponin-I


Sunquest Code:TROPI  
Epic Code:LAB747Epic Name:Troponin I
Synonyms:Troponin I; Ischemic; Cardiac Marker; TROPI; Cardiac Enzyme
Methodology:Chemiluminescence
CPT Code:----------CPTCODES HERE----------
Turnaround Time:Performed and reported 24 hours/day.


Collection Instructions

Specimen:Blood
Optimal Volume:2.5 mL
Minimum\Peds Volume:0.6 mL
Container:Green (lithium heparin, gel) (Green (lithium heparin) on ICE, Green (sodium heparin, no gel), Green (sodium heparin, no gel) on ICE, Red (no gel), Red or gold (gel))
Collection Instructions:Serial sampling is recommended to detect temporal rise and fall of cTnl levels characteristic of AMI.
Contraindications:Large doses of biotin (10 mg or more per day) may cause clinically significant interference in troponin levels. If interference is suspected, it is strongly recommended that biotin is discontinued for at least one week prior to retesting.


Processing and Shipping

Specimen Processing:Centrifuge and aliquot 1.25 mL, 0.2 mL minimum. Store in refrigerator.
Shipping Instructions:Ship at refrigerated temperature to arrive within 48 hours. Alternatively, ship on dry ice.
Test Performed at or Referral Lab Chemistry  (University of Minnesota Health Maple Grove Clinics, Fairview Range - FRMC, Range Clinics, UMMC-East Bank, Oxboro Bloom, Fairview Lakes - FLMC, Fairview Ridges - FRH, Fairview Northland - FNMC, Fairview Southdale - FSH, UMMC/UMMCH-West Bank, Grand Itasca GICH)


Interpretive

Critical Range:
1 year and older: Greater than 0.120 ug/L
GICH: All ages - greater than 0.500 ng/mL  
Reference Range:
0 - 0.045 ug/L Normal (10% CV and 99th percentile)
0.046 - 0.120 ug/L Risk stratification: Data indicates that patients with baseline cardiac Troponin I values above the 99th percentile uper reference limit had a significantly higher short-term risk of death or recurrent ischemic events after presentation.
Greater than 0.120 ug/L Diagnostic for acute, evolving or recent MI if typical rise and gradual fall of troponin with at least one of the following:
  • Ischemic symptoms
  • Pathologic Q waves on ECG
  • ECG changes indicative of ischemia (ST segment elevation or depression), or
  • Coronary artery intervention, i.e., angioplasty
 GICH: All ages - 0.0-0.34 ng/mL  
Limitations:1) Interpretation of cTnl results should be done only in the context of the overall clinical picture, e.g., clinical history, ECG, and other laboratory tests indicative of cardiac damage. The triage of patients with chest pain should be based on serial samples and the typical rise and fall pattern of cTnl characteristic of cardiac damage. 2) For troubleshooting purposes, if the cTnl result is inconsistent with the clinical picture and is persistently elevated, the sample should be tested for the presence of heterophilic antibodies. These antibodies may be present in the blood samples from individuals regularly exposed to animals or who have been treated with animal serum products. 3) Samples from patients receiving preparations of mouse monoclonal antibodies for therapy or diagnosis may contain Human Anti-Mouse Antibodies (HAMA). Such samples may show either falsely elevated or falsely depressed values when tested with this method. 4) Streptokinase may interfere negatively with the predicted concentration of cTnl. Care should be taken when interpreting cTnl results after administration of streptokinase.
Use:

The National Academy of Clinical Biochemistry Standards of Laboratory Practices (NACB) and the International Federation of Clinical Chemistry (IFCC) recommend a minimum of three serial blood samples within 24 hours of admission. Serial sampling is recommended to detect the temporal rise and fall of cTnl levels characteristic of AMI.

 

The Joint European Society of Cardiology/American College of Cardiology (ESC/ACC) and the NACB recommend that the diagnosis of AMI includes the presence of clinical history suggestive of Acute Coronary Syndrome (ACS) and a maximum concentration of cardiac troponin exceeding the 99th percentile of a normal reference population [upper reference limit (URL)] on at least one occasion during the first 24 hours after the clinical event.

 

The World Health Organization (WHO) requires two of the following criteria for the diagnosis of AMI: elevated cardiac markers results, evolutionary changes in ECG, history of chest pain.

 

Increased cTnl concentrations can be found in conditions other than AMI that can result in myocardial damage. These conditions include, but are not limited to, sepsis, congestive heart failure, hypertension with left ventricular hypertrophy, hemodynamic compromise, myocarditis, mechanical injury including cardiac surgery, defibrillation, and cardiac toxins such as anthracyclines. Factors such as these should be considered when interpreting results from any cTnl test method.

 



Click HERE to Report test errors or omissions.
*If no email program is associated with this computer, please contact:
systemlabguide@fairview.org for TestID: 2736"