Troponin Blood Test
Reviewed
Also called: Cardiac troponin, Troponin I, Troponin T, cTnI, cTnT
A troponin test measures the level of troponin in a sample of your blood. Troponin is a protein that's found in the cells of your heart muscle.
Specimen: Blood
Urgent safety information
If you have symptoms of a heart attack, call 911 immediately. Quick medical attention could save your life.
Emergency numbers on this page are for the United States. Outside the US, call your local emergency number.
Why this test may be ordered
- Assessment of possible heart attack
- Evaluation of acute chest pain or other concerning symptoms
- Monitoring selected conditions or procedures that can injure heart muscle
Preparation and collection
You don't need any special preparations for a troponin test. But, if you take vitamin B7, also called biotin, make sure you tell the health care provider who orders your test. Biotin and supplements that contain biotin can make your troponin levels appear lower than they really are.
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
If a result or symptoms suggest an emergency, get emergency medical help right away.
To understand the results of a troponin test for chest pain and/or other symptoms of a heart attack, your provider will consider your symptoms, medical history, and the results of other tests.
- Higher than normal troponin: If your test results show higher than normal amounts of troponin in your blood, it usually means you have some damage in your heart muscle. Very high troponin levels most often mean you've had a heart attack. Limitation: Higher than normal troponin levels don't always mean you've had a heart attack. Next step: Your provider will consider all the information about your condition to diagnose whether a heart attack caused the damage.
- Normal on the first test: If your first troponin test results are normal, you'll probably be retested during the next 12 hours. Limitation: That's because increased troponin levels usually don't show up for about 2 to 3 hours after a heart attack begins. Next step: In the meantime, the results of other tests and exams will help your provider know whether to start treatment for a heart attack right away.
- Normal 12 hours after symptoms began: If your troponin test results show normal troponin levels 12 hours after your symptoms began, you probably did not have a heart attack. Limitation: Biotin and supplements that contain biotin can make your troponin levels appear lower than they really are. Next step: If you have questions about your test results, talk with your provider.
- Assay type, sex-specific limits, kidney dysfunction, timing, and serial change can alter interpretation.
- Many conditions besides coronary blockage can raise troponin.
What to do next
Troponin levels can continue to rise for about 24 hours after a heart attack begins. So, if your test results show high troponin levels, you'll probably be tested two or more times over a 24-hour period.
- Which troponin assay and decision limit were used?
- Was the sample taken early enough that repeat testing is required?
- Does the pattern show a rise or fall and what other causes are being considered?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.