Test Overview
Test Methodology

Immunometric Chemiluminescence

Test Usage

Marker of myocardial injury. Troponin I is one of three proteins of the troponin complex that regulates the calcium mediated interaction of actin and myosin. Troponin I demonstrates slightly better cardiac specificity than does CK-MB. Serum levels of troponin I begin to rise 4 to 6 hours after an acute myocardial infarction, with peak concentrations being reached in approximately 12-18 hours after infarction. Unlike other cardiac markers (CKMB, Myoglobin), Troponin I levels remain elevated in plasma for several days before returning to normal. Troponin I may be elevated in a number of cardiac conditions other than AMI, including unstable angina.

Reference Range *

< 0.30 ng/mL

Test Details
Days Set Up
Daily, 24 hours
Analytic Time

2 hours

Soft Order Code
TROP
MiChart Code
Troponin I
Synonyms
  • Troponin
  • TROP
  • TROPONIN LEVEL
Laboratory
Chemical Pathology
Section
Automation
STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

Specimen Requirements
Collection Instructions

Collect specimen in a green top tube. Centrifuge, aliquot plasma into a plastic vial and refrigerate.

Alternate Specimen
Green top preferred. Green top serum separator tube (GPST) acceptable. Serum acceptable for Troponin but must be treated with heparin which delays TAT. Serial specimens should be collected in the same container type. [rev 8/03; 7/07; 3/11]
Normal Volume
0.5 mL plasma
Minimum Volume
0.25 mL plasma
Additional Information

Because of its greater specificity, the laboratory promotes the use of Troponin I as the primary marker for myocardial damage. Because Troponin I can remain elevated for many days after an infarction, the markers with much shorter time courses of disappearance such as CK-MB and myoglobin can be used to help ascertain the timing of the initial damage or detect reinfarction.

Billing
CPT Code
84484
Fee Code
23368
LOINC
10839-9
NY State Approved
No