Descriptions

Cardiac Biomarkers (Blood) Test

Does this test have other names?

CK, CK-MB, cardiac troponin T, troponin I, myoglobin, cardiac enzymes

What is this test?

This test measures the levels of cardiac biomarkers in your blood. These markers include enzymes, hormones, and proteins.

Cardiac biomarkers show up in your blood after your heart has been under severe stress and becomes injured because it isn't getting enough oxygen.

This might be because you've had a heart attack. But these levels can be high for other reasons. The levels of biomarkers are often used to quickly find out the size of a heart attack and how seriously your heart was affected. 

These cardiac biomarkers can be used to diagnose a heart attack:

Cardiac troponin. This protein is by far the most commonly used biomarker. It has the highest known sensitivity. It enters your bloodstream soon after a heart attack. It also stays in your bloodstream days after all other biomarkers go back to normal levels. Two forms of troponin may be measured: troponin T and troponin I. Troponin I is highly specific to the heart and stays higher longer than creatinine kinase-MB. 

Creatinine kinase (CK). This enzyme can also be measured several times over 24 hours. It will often at least double if you've had a heart attack.

But because levels of CK can go up in many other conditions besides a heart attack, it is not very specific.

CK-MB. This is a subtype of CK. It is more sensitive for finding heart damage from a heart attack. CK-MB rises 4 to 6 hours after a heart attack.

But it is generally back to normal in a day or two. Because of this, it's not helpful when a healthcare provider is trying to figure out if your recent chest pain was a heart attack.

Myoglobin. This is a small protein that stores oxygen. It is measured occasionally. Myoglobin is sometimes measured in addition to troponin to help diagnose a heart attack. It is also not very specific for finding a heart attack.