Troponin I Rule Out (0hr+2hr)

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Test Code: TNIRO

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Test Components

0 hour baseline high sensitivity TNI test collection (Troponin I 0Hr)

2 hour post baseline high sensitivity TNI test collection (Troponin I 2Hr)

Useful For

Exclusion diagnosis of acute myocardial infarction.

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)	Pediatric Minimum Volume (no repeat)
No	Plasma or Serum	Lithium-heparin Plasma Separator Tube (PST)	Serum Separator Tube (SST), Red Top Tube (RTT)	1.0 mL	0.3 mL	0.3 mL

Collection Processing Instructions

At the time of baseline TNI collection, phlebotomist will update the 2 hour TNI collection date/time information to be 2 hours post baseline date/time of collection.

Separate plasma or serum from the blood within 60 minutes of venipuncture. Specimen must be free of particulate matter including fibrin which can interfere with the assay.

For plasma samples only:
- Sites with centrifuges capable of reaching a speed of 4,400g can centrifuge the collection tube for 3 minutes.
- Sites with standard centrifugation must centrifuge the collection tube for 10 minutes at 1900g.

High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay. It is recommended that patients refrain from consuming any multivitamin or supplement containing biotin for at least 72 hours prior to collection of a blood sample.

Specimen Stability Information

Specimen Type	Temperature	Time
Serum or Plasma	Ambient	8 hours
	Refrigerate	<72 hours
	Frozen at -20 deg Celsius	1 month
	Frozen at -70 deg Celsius	> 1 month

Rejection Criteria

Serum specimens exposed to repeated freeze/thaw cycles.

Interference

High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay.

Heterophile Antibodies and Rheumatoid factor can react with reagent immunoglobulins. Human anti-mouse antibodies may cause falsely low or high results. Troponin autoantibodies may interfere.

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Marshfield	Monday through Sunday	Less than 1 hour	Chemiluminescent Immunoassay/Siemens Centaur

Reference Range Information

Performing Location	Reference Range
Marshfield	Female: <= 37 ng/L Male: <= 57 ng/L
The 99th percentile Upper Reference Limit (URL) for troponin I in a normal reference population is used. All assays show less than 10% imprecision (<10% CV) at 99th percentile upper reference limit value. Reference values were adopted and validated from the manufacturer's normal population studies.

Interpretation

For high sensitivity TNI assay used at MMC Marshfield lab:

Serial measurements may be necessary to confirm or exclude the diagnosis of acute coronary syndrome. Repeat testing in 2 hours if clinically indicated.

-If zero hour TNI is <8 ng/L AND delta at two hours is < 7 ng/L, then rule out Acute MI.

-If zero hour TNI is >=120 ng/L OR delta at two hours is >=20 ng/L, then rule in Acute MI.

-If results do not fall into above, then observe. Getting additional draws (e.g. at 4 hours) may be helpful.

Cardiac Troponin I (cTnI) is very specific to myocardium and not expressed during any developmental stage in skeletal muscle. Increased levels of cTnI are detected with myocardial injury. Detection of rise and/or fall of cTnI are essential to establish the diagnosis of acute myocardial infarction (MI). An increased cTnI concentration is defined as a value exceeding the upper reference limit of the 99th percentile of a normal reference population and is designated as the decision limit for the diagnosis of acute MI (Third Universal definition of Myocardial infarction, ESC/ACCF/AHA/WHF Expert consensus document. Circulation 2012; 126: 2020). Demonstration of rising and/or falling pattern is required to distinguish acute from elevations of cTnI levels that are associated with chronic heart diseases.

A positive cTnI result therefore, is not always indicative of ischemia. Other conditions resulting in myocardial cell damage can contribute to elevated cTnI include, but are not limited to:

Elevated Tnl Values in Patients Without AMI
Cardiac conditions
• Angina/Unstable Angina
• Atrial fibrillation
•   Cardiac surgery
• Cardiomyopathy
• Congestive heart failure
• Coronary artery disease
•   Heart failure
•   Hypertensive urgency
•   Myocarditis
•   Pericarditis
• Pulmonary emoblism
•   Recent cardiac intervention
•   Severe valvular heart disease
•   Tachycardia

Non-cardiac conditions

• Chronic lung disease

•   Cardiac contusion related to a traumatic injury
•   Renal failure
•   Pneumonia
•   Pulmonary embolism
For assessing acute MI, blood samples should be drawn at the time of admission and repeated at 3 to 6 hours intervals. On certain occasions additional samples between 12 and 24 hours may be required if earlier measurements are not elevated and clinical suspicion is high for MI.

Test Components

0 hour baseline high sensitivity TNI test collection (Troponin I 0Hr)

2 hour post baseline high sensitivity TNI test collection (Troponin I 2Hr)

Ordering Applications

Ordering Application	Description
Cerner	Troponin I Rule Out (0hr+2hr)
COM	Troponin I Rule Out (0hr+2hr)

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)	Pediatric Minimum Volume (no repeat)
No	Plasma or Serum	Lithium-heparin Plasma Separator Tube (PST)	Serum Separator Tube (SST), Red Top Tube (RTT)	1.0 mL	0.3 mL	0.3 mL

Collection Processing

At the time of baseline TNI collection, phlebotomist will update the 2 hour TNI collection date/time information to be 2 hours post baseline date/time of collection.

Separate plasma or serum from the blood within 60 minutes of venipuncture. Specimen must be free of particulate matter including fibrin which can interfere with the assay.

Specimen Stability Information

Specimen Type	Temperature	Time
Serum or Plasma	Ambient	8 hours
	Refrigerate	<72 hours
	Frozen at -20 deg Celsius	1 month
	Frozen at -70 deg Celsius	> 1 month

Rejection Criteria

Serum specimens exposed to repeated freeze/thaw cycles.

Interference

High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay.

Heterophile Antibodies and Rheumatoid factor can react with reagent immunoglobulins. Human anti-mouse antibodies may cause falsely low or high results. Troponin autoantibodies may interfere.

Useful For

Exclusion diagnosis of acute myocardial infarction.

Test Components

0 hour baseline high sensitivity TNI test collection (Troponin I 0Hr)

2 hour post baseline high sensitivity TNI test collection (Troponin I 2Hr)

Reference Range Information

Performing Location	Reference Range
Marshfield	Female: <= 37 ng/L Male: <= 57 ng/L
The 99th percentile Upper Reference Limit (URL) for troponin I in a normal reference population is used. All assays show less than 10% imprecision (<10% CV) at 99th percentile upper reference limit value. Reference values were adopted and validated from the manufacturer's normal population studies.

Interpretation

For high sensitivity TNI assay used at MMC Marshfield lab:

Serial measurements may be necessary to confirm or exclude the diagnosis of acute coronary syndrome. Repeat testing in 2 hours if clinically indicated.

-If zero hour TNI is <8 ng/L AND delta at two hours is < 7 ng/L, then rule out Acute MI.

-If zero hour TNI is >=120 ng/L OR delta at two hours is >=20 ng/L, then rule in Acute MI.

-If results do not fall into above, then observe. Getting additional draws (e.g. at 4 hours) may be helpful.

A positive cTnI result therefore, is not always indicative of ischemia. Other conditions resulting in myocardial cell damage can contribute to elevated cTnI include, but are not limited to:

Elevated Tnl Values in Patients Without AMI
Cardiac conditions
• Angina/Unstable Angina
• Atrial fibrillation
•   Cardiac surgery
• Cardiomyopathy
• Congestive heart failure
• Coronary artery disease
•   Heart failure
•   Hypertensive urgency
•   Myocarditis
•   Pericarditis
• Pulmonary emoblism
•   Recent cardiac intervention
•   Severe valvular heart disease
•   Tachycardia

Non-cardiac conditions

• Chronic lung disease

•   Cardiac contusion related to a traumatic injury
•   Renal failure
•   Pneumonia
•   Pulmonary embolism
For assessing acute MI, blood samples should be drawn at the time of admission and repeated at 3 to 6 hours intervals. On certain occasions additional samples between 12 and 24 hours may be required if earlier measurements are not elevated and clinical suspicion is high for MI.

For more information visit:

http://labtestsonline.org

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Marshfield	Monday through Sunday	Less than 1 hour	Chemiluminescent Immunoassay/Siemens Centaur

For billing questions, see Contacts

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For most current information refer to the Marshfield Laboratory online reference manual.

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For high sensitivity TNI assay used at MMC Marshfield lab:

Serial measurements may be necessary to confirm or exclude the diagnosis of acute coronary syndrome. Repeat testing in 2 hours if clinically indicated.

-If zero hour TNI is <8 ng/L AND delta at two hours is < 7 ng/L, then rule out Acute MI.

-If zero hour TNI is >=120 ng/L OR delta at two hours is >=20 ng/L, then rule in Acute MI.

For high sensitivity TNI assay used at MMC Marshfield lab:

Serial measurements may be necessary to confirm or exclude the diagnosis of acute coronary syndrome. Repeat testing in 2 hours if clinically indicated.

-If zero hour TNI is <8 ng/L AND delta at two hours is < 7 ng/L, then rule out Acute MI.

-If zero hour TNI is >=120 ng/L OR delta at two hours is >=20 ng/L, then rule in Acute MI.

26157 Troponin I Rule Out (0hr+2hr)