Troponin test

A troponin test measures the troponin level in a sample of your blood. Troponin is a protein found in your heart muscle cells.

Normally, troponin levels in the blood are so low that only the most sensitive types of tests can measure them. But if your heart muscle is damaged, troponin enters your bloodstream, and your troponin levels in the blood will increase.

The troponin test is primarily used to help diagnose heart attacks. Heart attacks damage the heart by suddenly blocking the blood flow that brings oxygen to part of the heart muscle. Without oxygen from the blood, heart muscle cells die and release troponin.

Troponin test results can confirm heart muscle damage due to a heart attack. The more damage to the heart, the more troponin is released into the bloodstream. So measuring the amount of troponin in the blood can also help estimate how many parts of the heart have been damaged. Higher than normal levels of troponin can also be found in other conditions that can damage heart muscle.

Two types of troponin can be measured to diagnose heart damage. They are called troponin I and troponin T. The tests can measure either type.

Other names: cardiac troponin I (cTnI), cardiac troponin T (cTnT), cardiac troponin (cTn), troponin I, and heart-specific troponin T

A troponin test is primarily used to:

• Confirm whether a person is having a heart attack or has recently had a heart attack. This is the most common reason for taking a troponin test. The test is usually done in a hospital emergency room along with other cardiac tests, such as an EKG (also called an ECG or electrocardiogram).
• Diagnosing and monitoring unstable angina. Angina is chest pain that occurs if part of the heart muscle doesn't get as much blood as needed. Unstable angina is a type of angina that occurs at any time, even at rest. It is a medical emergency because it can lead to a heart attack.
• Check heart health after surgery that could damage the heart. In this case, a troponin test may be done before and after surgery so that the results can be compared.

You may need a troponin test if you have symptoms of a heart attack. Symptoms may start slowly or suddenly. They can be mild or intense, and they can appear and go over several hours. They include:

• Chest pain, heaviness, or discomfort in the center or on the left side of the chest
• Pain or discomfort in one or both arms, your back, your back, your shoulders, your neck, your jaw, or above your belly button
• Difficulty breathing at rest or during light physical activity
• Nausea and vomiting
• Feeling unusually tired for no reason, sometimes for days
• Dizziness and lightheadedness
• Excessive sweating for no reason
• Fast or irregular heart rate (arrhythmia)

If you have symptoms of a heart attack, call 911 immediately. Prompt medical attention could save your life.

You may also need a troponin test if you are having surgery that could affect your heart.

You do not need special preparations for a troponin test. But, if you are taking vitamin B7, also known as biotin, be sure to tell the health professional requesting your test. Biotin and supplements containing biotin can cause your troponin levels to appear lower than they actually are.

There is very little risk in taking a blood test. You may feel a slight pain or bruise where the needle was inserted, but most symptoms go away quickly.

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.

In general:

• If the results of your first troponin test are normal, you will probably be retested within the next 12 hours. This is because increased troponin levels usually don't occur until about 2 to 3 hours after the onset of a heart attack. Thus, the results of a subsequent test may show higher than normal levels of troponin. In the meantime, the results of other tests and exams will help your provider know whether to start treating a heart attack right away.
• If your troponin test results show normal troponin levels 12 hours after the start of your symptoms, you probably didn't have a heart attack.
• If your test results show higher than normal amounts of troponin in your blood, it usually means that you have suffered damage to the heart muscle. Your provider will take into account all the information about your condition to diagnose whether a heart attack caused the damage. Very high troponin levels most often mean that you have had a heart attack.

Higher than normal levels of troponin don't always mean you've had a heart attack. They can be caused by unstable angina and many other conditions that can damage the heart, including:

• Irregular heartbeat (arrhythmia), especially a heart rate that is too fast
• Heart failure
• Heart valve disease
• Heart muscle infection or inflammation (myocarditis)
• Heart surgery
• Intense exercise over a long period of time, such as running a marathon
• Chest injuries
• Chronic kidney disease
• A blood clot in your lungs (pulmonary embolism)
• Sepsis
• A severe COVID-19 infection

If you have high troponin levels but your provider doesn't think you've had a heart attack, you may have further tests to find the cause.

If you have questions about your test results, talk to your provider.

Learn more about lab tests, reference ranges, and understanding results.

Troponin levels may continue to rise for about 24 hours after the onset of a heart attack. So, if your test results show high levels of troponin, you will likely be tested twice or more over a 24-hour period.

The results of these tests show how quickly your troponin level has increased and the highest level it has reached. This information helps estimate how much of your heart muscle is damaged and how well you could recover.

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