What Is CK-MB (Creatine Kinase-MB)?
What it is
CK-MB is a cardiac-specific isoenzyme of creatine kinase, released when heart muscle is injured.
Why it matters
A classic cardiac marker, largely superseded by troponin but still used in some protocols.
Specimen
Whole blood / serum / plasma
Interpretation
Elevated = myocardial injury (cardiac isoenzyme).
Limitations
Largely superseded by troponin; interpret with other markers.
Related test: CK-MB Rapid Test — specimen: WB / S / P
Frequently Asked Questions
Is CK-MB still used? Largely superseded by troponin but retained in cardiac panels as an adjunct.
Related knowledge
References
- Thygesen K et al. Fourth universal definition of myocardial infarction. Eur Heart J. 2019;40(3):237-269.
Last reviewed: 2026-09-12