Laboratory: Clinical Biochemistry  (POC (Point of Care) TEST)
Test Name:
High-Sensitivity Troponin I (i-STAT) - (B)
Test Code: HTNI
Clinical Information:
Alternate Name(s): Cardiac Troponin I

                                 POCT Troponin


Description: Troponin I is a regulatory subunit of the contractile apparatus of myocardial tissue. High-sensitivity Troponin I (hs-TnI) testing is used to detect acute myocardial injury and as an aid in the diagnosis of myocardial infarction (MI).


Test Indications: For emergency, urgent care, and inpatients only.


This test is not intended for long-term monitoring and risk stratification.
 

For outpatient Troponin requests, please order TROPONIN T, HIGH-SENSITIVITY (hsTnT) 

 
Collection Devices:
Alternate Device: Li Heparin Plasma Separator Tube(s) - Full Tube Collection 

Quantity- 1
Specimen Required: Collection Information: Vacutainers must be filled to capacity and mixed well.

Blood gas syringes must be at least half filled and mixed well.

Special Processing: DO NOT CENTRIFUGE. Assay must be performed with whole blood only.

Always remix whole blood thoroughly before filling the cartridge.

Specimen Stability:

Ambient: Whole blood, 2 hours

Refrigerated: DO NOT REFRIGERATE

Frozen: DO NOT FREEZE
Referral:
Requisition:
Reference Values:
Reference Intervals:

Female ≥ 18y    ≤ 13 ng/L

Male ≥ 18y        ≤ 28 ng/L

Pediatric           Reference values have not been established for pediatric patients.

Critical Value: Critical values are not called for this test.

Method of Analysis: Enzyme-linked immunosorbent assay (ELISA) on Abbott i-STAT System 1

 
Availability:
Daily or Stat
Available at rural sites only for emergency, urgent care, and inpatients.
See Also:
More Information:
Additional Information: 

IMPORTANT:

·        High-sensitivity Troponin I and high-sensitivity Troponin T are not interchangeable

·        Always use the same assay for serial results in ACS protocols, and interpret alongside clinical presentation and EKG

Increased cardiac troponin occurs when there is cardiac damage, and is not specific for ischemic cardiac injury

Interpretation:

A baseline hs-TnI should be obtained upon patient’s first medical contact. If STEMI is ruled out and TIMI score is 2 or less, repeat hs-TnI at 2 hours from baseline. For complete information, please consult the Cardiac Sciences Manitoba algorithm for Chest Pain with Cardiac Features.

 

Assay interferences:

  • Patients may have autoantibodies which may cause falsely low results. 
  • Conversely, some patients may develop macro-troponin complexes (immunoglobulin + troponin I) that can cause persistent false elevations. 
  • Bilirubin above 475 µmol/L will cause falsely decreased results.
  • Methyldopa can lead to increased results.

 

References:

 1.      Thygesen K, Alpert JS, Jaffe AS, et al. ESC/ACC/AHA/WHF Expert Consensus Document: Fourth Universal Definition of Myocardial Infarction (2018). Circulation;138:e618–e6.

2.      Thieβen N, Pickering JW, Kellner C, et al. A Common Algorithm for Cardiac Troponin to Rule Out and Rule in Myocardial Infarction (2025). Can J Cardiol. P1351-1360.

3.      Gulati M, Levy PD, Mukherjee D, et al. AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain (2021). Circulation. 144(22): e368-448.