Troponin

Does this test have other names?

Cardiac troponin (cTn), cardiac troponin I (cTnI), cardiac troponin T (cTnT), high-sensitivity cardiac troponin (hs-cTn)

What is this test?

This test measures the amount of the protein troponin in your blood.

Troponin is a protein found in cells in your heart muscle. When these cells are injured, they can release troponin and other substances into the blood. This usually happens when the heart becomes damaged because it isn't getting enough oxygen and nutrients.

Measuring your troponin level can often quickly tell your doctor if you are having a heart attack. During a heart attack, the arteries that provide the heart with blood become blocked.

Why do you need this test?

You may need this test if your doctor suspects that you are having a heart attack. Symptoms of a heart attack often include:

• Chest pain that may feel like pressure, tightness, squeezing, or aching.

• Pain or discomfort that spreads to the shoulder, arm, neck, back, jaw, or upper belly.

• Shortness of breath.

• Lightheadedness or dizziness.

• Nausea or vomiting.

• Heartburn or indigestion.

• Sudden sweating.

• Extreme tiredness.

What other tests might you have along with this test?

Your doctor may also order other tests to diagnose a heart attack and to learn more about how it's affecting your heart. These tests often include:

• Electrocardiogram to measure the heart's electrical activity and rhythm.

• Blood tests to measure creatine kinase MB, a substance found in heart muscle and other tissues.

What do your test results mean?

Test results may vary depending on your age, sex, and health history. Your test results may also vary depending on the lab used. Ask your doctor what your test results mean for you.

Results are given in nanograms per milliliter (ng/mL) or liter (ng/L). Different labs use slightly different normal ranges and results can vary depending on the type of troponin test done. For example, the normal range for troponin I is between 0 and 0.04 ng/mL, but for high-sensitivity cardiac troponin (hs-cTn) normal values are below 14ng/L. However, there are slight differences in normal ranges between men and women based on the type of troponin being measured.

Other types of heart injury may cause a rise in troponin levels. These include:

• Atrial fibrillation.

• Heart failure.

• Myocarditis.

• Damage to the heart from anthracycline medicines. These are used for cancer treatment.

Conditions in other parts of your body may cause troponin levels to rise. These include:

• A blood clot in your lungs (pulmonary embolism).

• Chronic kidney disease.

• Chronic obstructive pulmonary disease.

High-sensitivity cardiac troponin (hs-cTn)

High-sensitivity cardiac troponin is a common type of testing that gives a fast initial evaluation of chest pain symptoms. This may help diagnose heart injury and acute coronary syndrome earlier. Your doctor will explain which type of troponin testing was done and what the results mean for you.

How is this test done?

The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand. 

Does this test pose any risks?

Having a blood test with a needle carries some low risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.

What might affect your test results?

Having this test too soon after a heart attack may give a false-negative. Cardiac troponin takes a few hours to rise after heart-cell death begins and can take several days to clear from the bloodstream. Your doctor may need to measure it several times over a few hours after the symptoms start.

How do you get ready for this test?

You don't need to prepare for this test. Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.