About the Test
Purpose of the test
The most common purpose of troponin testing is to establish whether a patient’s symptoms are related to a heart problem. Because troponin is not normally detectable in the blood, even small amounts of troponin can indicate some injury to the muscles of the heart.
Troponin testing is often used to detect acute coronary syndrome, which describes several conditions that reduce blood flow to the heart, including:
- Heart attack: Also called acute myocardial infarction (MI), a heart attack is when the flow of blood to the heart is blocked, which can result in life-threatening damage to the heart.
- Unstable angina: Unstable angina is chest pain, discomfort, or pressure caused by reduced blood flow to the heart. Unstable angina may result in a heart attack.
Another purpose of troponin testing is to evaluate patients after surgery that could affect the heart. Troponin levels may be measured prior to the procedure and monitored after the procedure is complete to detect any damage or injury to the heart.
What does the test measure?
The troponin test measures the amount of troponin T or troponin I in the bloodstream. These two proteins are types of cardiac biomarkers. Cardiac biomarkers are substances that are released into the blood when the heart is damaged or stressed.
Troponin plays an important role in maintaining a heartbeat and consists of three parts: troponin T, troponin I, and troponin C. Tests for troponin measure blood levels of either troponin T or troponin I. Either test may be used, and the test a person receives depends on several factors including the laboratory used.
When should I get a troponin test?
Your doctor may recommend troponin testing if you have experienced symptoms of a heart attack. If you are in a hospital or emergency room with signs of a possible heart attack, your doctor will usually order a troponin test as part of your medical evaluation. Troponin levels typically begin to increase within two to three hours after onset of a heart attack.
You should seek medical attention if you have signs of a heart attack. Common symptoms of a heart attack include:
- Chest pain
- Squeezing or heavy pressure on your chest
- Pain radiating from your chest to your arms, shoulders, neck, teeth, or jaw
- Sudden fatigue or weakness
- Nausea or vomiting
- Shortness of breath
- Feeling faint or lightheaded
- Heart palpitations or irregular heartbeat
- Anxiety or feelings of impending doom
Troponin testing may also be ordered to evaluate patients after surgery that could affect the heart. If you are at high risk of cardiac injury during surgery, your doctor may suggest obtaining a baseline troponin test prior to having the medical procedure and repeating troponin testing after the procedure is complete.
Finding a Troponin Test
How to get tested
Troponin testing is usually performed in a clinical setting. If you are in the emergency room or have been admitted to the hospital with recent symptoms of a heart attack, your troponin levels may be measured. Troponin testing is usually repeated two or more times over the next 24 hours to monitor for sharp increases or changes in troponin levels over time.
Can I take the test at home?
Troponin testing is typically performed in a hospital or clinical setting and cannot be performed at home.
How much does the test cost?
Because the troponin test is typically performed in an emergency room or hospital, most health insurance providers cover the cost of the test. You can contact your insurance provider if you are unsure whether troponin testing is covered and whether you have a deductible or copays.
For patients without health insurance, talk to your doctor or a hospital administrator for more information about the cost of testing.
Taking the Troponin Test
A blood sample is needed for a troponin test. The sample is usually taken from a vein in the arm while you are in the hospital or emergency room.
Before the test
There are no special preparations for taking a troponin test.
During the test
During a troponin test, a blood sample is taken from a vein in your arm. You may feel a prick or small sting when the needle goes into your vein. A small amount of blood is collected into a test tube or vial. The troponin test is quick and usually takes only a few minutes.
After the test
After the blood draw, the nurse or doctor may place a bandage over the area on your arm where blood was drawn. Talk to your health care provider about any activity restrictions after the test.
Troponin Test Results
Receiving test results
Because troponin testing is most often performed in an emergency room or hospital, test results are usually available quickly. A heart attack is an emergency medical situation, and a quick diagnosis can be imperative to saving a person’s life. Many hospitals have labs on site that provide rapid test results to help guide treatment recommendations.
Interpreting test results
Troponin test results are typically reported using a reference range, which is the amount of troponin that is expected in healthy patients. The reference ranges for troponin testing vary depending on the laboratory and type of test performed, so it is important to read your test report carefully.
The significance of troponin levels can depend on your current symptoms and overall health. Your doctor considers these and other factors when interpreting your troponin test result.
Troponin levels typically rise over the first 12 hours after onset of a heart attack. If your troponin levels are measurable within 6 to 12 hours after experiencing symptoms such as chest pain, it may indicate that you have suffered a heart attack. Following a heart attack, troponin levels may remain high for up to one to two weeks.
If your troponin levels are normal over this 12 hour period, it is unlikely that you had a heart attack.
Troponin levels can be elevated as a result of health conditions other than heart attack. Conditions that may cause a patient to have elevated troponin levels include:
- Other types of acute coronary syndrome, including unstable angina
- Acute myocarditis, which is inflammation of the heart muscle
- Congestive heart failure
- Abnormally fast heartbeat
- Kidney disease
- Pulmonary hypertension, which is elevated blood pressure in the lung arteries
- Pulmonary embolism, which is a blood clot in the lungs
- Takotsubo syndrome, a type of stress induced heart disease
- Weakening of the heart muscle
- Trauma to the heart
- Stress of the heart, including from vigorous exercise
- Severe COVID-19
Increased troponin levels may also be the result of certain medical procedures. In general, troponin levels may increase in patients who have various types of heart-related operations, open-heart surgery, or cardiac defibrillation
Because the results of troponin testing must be interpreted alongside other information about your health, it is important to talk with your doctor about what your test results mean for you and your medical situation.
Are test results accurate?
Troponin testing is widely accepted as an important indicator of a heart problem, and the test is frequently used to diagnose a heart attack. That said, no test is perfect, and both false negative and false positive results can occur.
False negative results happen when troponin is not elevated after a heart attack occurs. False negative results may occur for different reasons:
- Test timing: It can take a few hours for troponin levels to rise after a heart attack, so initial testing may not show detectable amounts of troponin. In order to rule out a false negative result, troponin levels are typically tested again over a 24-hour period to look for rising values.
- Biotin supplement intake: Biotin is a type of B vitamin. Multivitamins and dietary supplements that contain biotin may cause falsely low troponin levels. For this reason, you should tell your doctor if you take any dietary supplement that contains biotin.
False positive results occur when troponin is elevated but no heart attack actually occurred. These misleading results can occur because of other medical conditions that can increase troponin levels.
Do I need follow-up tests?
For patients being assessed for a heart attack, current guidelines recommend rechecking troponin levels one or more times over a 24-hour period to look for changing levels over time.
Your doctor may order additional tests along with your troponin test as part of your initial clinical assessment. These tests may include:
- Imaging of your heart and lungs
- Electrocardiogram (ECG) to record the electrical activity of your heart
- Complete blood count (CBC)
- Other blood work including magnesium levels, creatinine, glucose, electrolytes, and blood urea nitrogen (BUN)
Talk with your doctor or cardiologist about which follow-up tests are important for your medical situation.
Questions for your doctor about test results
When discussing your troponin test results with your doctor, the following questions may help you understand what they mean for you:
- What are my troponin levels?
- Did I have a heart attack?
- Do I have damage to the muscles in my heart?
- Do you recommend any other tests or procedures?
- Should I have my troponin levels tested again?