This test is not available for clinical use.

Specimen Collection

Sample stability:

• 5 hours at 20-25 ^o C
• 12 hours at 2-8 ^o C
• 3 months at -20 ^o C

4.5 mL PST Blood (Preferred - effective from 4th Mar 2013)

5 mL Heparin Blood

4 mL Plain Blood

3.5 mL SST Blood

0.5 mL Paediatric Microsample Blood

0.5 mL Paediatric Micro-heparin Blood
Reference Intervals

Troponin T is a more sensitive and specific marker of myocyte damage and is the test of choice for the diagnosis of myocardial infarction and as a prognostic indicator in acute coronary syndromes.

Units: ug/L

	97.5th centile	99th centile
women	<3.6	<4.9
men	<4.9	<6.2

If CKMB > 4.0 ug/L and total CK > 400 U/L, the Relative Index (or ratio) will be calculated:

Relative Index = (CKMB / Total CK) x 100

If the Relative Index is < 1.0, myocardial damage is probably excluded.
If the Relative Index is > or = 2.0, myocardial damage highly likely.

A Relative Index between 1 - 2 is inconclusive, in which case a second sample is suggested if the total CK activity is still rising.

• The enzyme activity will not start to rise until 4 - 6 hours after infarction. Testing too early will give a false negative result. If in doubt, take another sample for analysis about 4 - 6 hours later. The peak elevation of CKMB enzyme activity will occur 24 - 48 hours after infarction and levels will usually remain elevated for 3 - 5 days.

Uncertainty of Measurement: 7%

Turnaround Time: Within 3 hours

Urgent sample within 1 hour. Contact laboratory to notify.

Assay Method

Principle: Sandwich type immunoassay with chemiluminescence detection

Reagents: Roche e-pack CKMB

Analyser: Cobas e801

Contact Information

Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.

If the query concerns a specific patient please include the NHI number in your email.

If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).

Individual chemical pathologists may be contacted but will not be available at all times.

After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.

Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402

Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052

Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427

Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427

Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427

Specimen Transport Instructions for Referring Laboratories

This test is ONLY available for research studies. Clinical samples will be declined.

Specimens from referral labs in Auckland:

Please transport on ice - to be tested within 8 hours.

Samples from outside Auckland:

Please centrifuge and separate the plasma/serum.

Freeze prior to transportation.

Last updated at 15:26:00 06/01/2025