What is this test?
CK-MB is an isoenzyme found in heart muscle but also in some skeletal muscle. It can rise after heart or muscle injury; high-sensitivity troponin is generally more cardiac-specific for acute injury.
Why might it be ordered?
- When a clinician needs CK-MB for a particular cardiac or muscle assessment.
- To follow a change when this marker is part of the local clinical protocol.
What sample is needed?
A blood sample is required. The laboratory chooses the correct tube and handles the sample for this test.
How should you prepare?
No special fasting is usually needed. New chest pressure, severe breathlessness, sweating or collapse requires emergency assessment rather than waiting for a laboratory result.
How should you understand the result?
CK-MB is interpreted with symptom timing, ECG, troponin and total CK. A rise does not by itself prove a heart attack.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.