Creatine Kinase-MB Test
24,950 Kshs | Home Collection Available
Synonyms
CK-2, CK-MB
Purpose
Clinicians measure the MB isoenzyme of creatine kinase in the blood with the CK‑MB test. When a myocardial infarction injures heart muscle cells, CK‑MB leaks into the bloodstream, making it a valuable marker of cardiac damage.
For a full diagnostic picture, the test can be done alongside Troponin I or T, Total Creatine Kinase (CK), Electrocardiogram (ECG), and Myoglobin.
Patient Preparation
The pattern of serial CK-MB determinations is more informative than a single determination.
Samples
1ml with a minimum volume of 0.7ml of Serum collected in a Gel-barrier tube, red-top tube. If you use a red top, transfer the separated serum to a plastic transport tube. Store the sample at room temperature.
Reference Range
Male:0.0-10.4ng/ml, female: 0.0-5.3ng/ml
Results Turnaround
1-2 days after receipt of samples
Diseases / Diagnostic indicators
The CK‑MB test helps confirm a myocardial infarction (MI) and monitor the success of treatment by tracking how CK‑MB levels change over time. Here are some possible outcomes of the test;
Elevated CK‑MB Levels (4–6 hours post‑MI)
- Confirm acute heart muscle injury. The degree of elevation generally correlates with the size of the infarct.
Peak CK‑MB Levels (18–24 hours post‑MI)
- Mark the maximum release of the enzyme; guides assessment of infarct extent and helps plan ongoing care.
Declining CK‑MB Levels (48–72 hours post‑MI)
- Indicate that the acute phase has passed and treatment (e.g., reperfusion therapy) is effective.
Secondary Rise in CK‑MB
- Suggests reinfarction or extension of the original infarct, prompting immediate re‑evaluation of therapy.
Normal CK‑MB Levels
In the absence of symptoms, typically rule out significant ongoing cardiac muscle damage. Continuous monitoring may still be warranted if clinical suspicion remains high. For more on CK-MB testing, read this study.