Troponin T, High Sensitive

Test Name

Troponin T (5th Gen) Powerchart: Troponin T

Type Specimen

Lithium heparin plasma (green top tube)

LIS Code

TNT5

Availability

7 days per week, 24 hours per day

Lab Section

Automated Testing Laboratory

Fluid Type

Lithium heparin plasma only

Fluid Type And Minimum Volume

1 mL plasma

Summary Test Name

Troponin T (5th Gen) Powerchart: Troponin T

Specimen Stability

Stable for 24 hours at 2 - 8 degrees C, 12 months at -20 degrees C, freeze only once

Stat Availability

7 days per week, 24 hours per day

Test Turnaround Time Routines And Stats

1 hour

Preferred Volume

Full green top tube

Reference Value

Reference Value:

cTnT >52 ng/L:  Myocardial necrosis present.  This may be due to acute myocardial ischemia (AMI) or other myocardial injury.

cTnT <14 ng/L (Females) or <20 ng/L (Males):  99th percentile upper reference limit for ostensibly healthy adult reference population.

          TNT5 Comment:

To use the high-sensitivity cTnT assay, at least 2 blood samples should be drawn at time 0 and then at least 1h later.  

If the cTnT concentration at time 0 is ≥53 ng/L in a patient whose clinical presentation is consistent with acute coronary syndrome, then there is a high likelihood that acute myocardial injury is present. However, confirmation of acute myocardial injury still requires a second cTnT to be drawn.

Delta cut-offs for determining the presence of acute myocardial injury have been validated at the 1-hour and 2-hour time points referenced here.

A 1-hour delta troponin >5 ng/L indicates acute myocardial injury.

A 2h delta troponin >7 ng/L indicates acute myocardial injury. 

Values below these are consistent with chronic myocardial injury.

For patients where there is a high index of suspicion for acute coronary syndrome, repeating the tests at 1 or 2 hours, and calculating a new delta, may be indicated.

If the second sample is collected in less than 60 minutes, no delta calculation will be performed.

Deltas for blood samples drawn more than 3 hours apart have not been validated and will not be reported.  Please interpret with caution.

          Delta Calculations:

    • Delta < 60 minutes – no delta calculation, result as NCAL
    • Delta 60-119 minutes – 1-hour delta calculation
    • Delta 120-179 minutes – 2-hour delta calculation
    • Delta >179 minutes – no delta calculation, result as NCAL

Delta Interpretations:

One (1) hour

  • Delta 3-5 ng/L, INDETERMINATE
  • Delta <3 ng/L, NEGATIVE
  • Delta >5 ng/L, POSITIVE

Two (2) hour

  • Delta 3-7 ng/L, INDERTEMINATE
  • Delta <3 ng/L, NEGATIVE
  • Delta >7 ng/L, POSITIVE