Troponin refers to three different proteins that help regulate the contractions of the heart and skeletal muscles. High troponin levels can indicate a problem with the heart.
The three proteins are troponin C, troponin I, and troponin T. Troponin C binds calcium and transports troponin I so muscles can contract. Troponin T binds troponin proteins to muscle fibers.
The heart releases troponin into the blood following an injury, such as a heart attack. High troponin levels usually mean a person has recently had a heart attack. The medical term for this attack is myocardial infarction.
The heart is essentially a muscle, releasing troponin into the bloodstream when it sustains damage. Troponin levels in the blood are typically very low, but injuries to the heart can cause them to increase significantly.
Troponin tests typically measure the levels of troponin I or troponin T in the blood as a way to check for heart damage.
Keep reading to learn more about the normal range of troponin, what to expect during a troponin test and the treatment options for high troponin levels.
Troponin levels are usually so low that standard blood tests cannot detect them. Even small increases in troponin can indicate some damage to the heart.
Significantly raised troponin levels, particularly those that rise and fall over a series of hours, are a strong indication of a heart injury.
The range for “normal” troponin levels can vary among laboratories, so it is best to discuss the results with the doctor who ordered the test. Laboratories measure troponin in nanograms per milliliter (ng/ml) of blood.
Laboratories may use the following as the normal and at-risk ranges of troponin:
|Normal range||Probable heart attack|
|0–0.04 ng/ml||Above 0.40 ng/ml|
Having a result between 0.04 and 0.39 ng/ml often indicates a problem with the heart. However, a very small number of healthy people have higher-than-average levels of troponin. Due to this, if the result is in this range, a doctor may check for other symptoms and order further tests before making a diagnosis.
Many labs in the United States are now using a high-sensitivity version of the troponin test, which the Food and Drug Administration (FDA) approved in 2017. This newer test can detect elevated troponin levels earlier than previous versions.
Doctors usually order a series of troponin tests to monitor how a person’s levels change over time.
Very high levels of troponin typically indicate that a person has had a heart attack, which can occur if the blood supply to some of the heart muscle suddenly becomes blocked.
Troponin levels that are lower but still elevated may point to another diagnosis.
Elevated troponin levels can occur as a result of both cardiac and noncardiac conditions. Possible causes include:
- sepsis, which is a severe and potentially life threatening reaction to an infection entering the bloodstream
- kidney failure or chronic kidney disease
- heart failure
- chemotherapy-related damage to the heart
- pulmonary embolism
- heart infection
- myocarditis, which is inflammation of the heart
- heart damage from using recreational drugs, such as cocaine
- a traumatic injury to the heart, such as from a sudden, hard blow to the chest
High troponin levels are a symptom, not a diagnosis, so treatment will focus on finding and addressing the underlying cause.
Very high levels of troponin usually indicate that a person has recently had a heart attack. The treatment for a heart attack depends on whether the blockage preventing blood flow to the heart is partial or complete.
Some common treatments following a heart attack
- clot-dissolving medications
- coronary angioplasty, which is a procedure that involves threading a small balloon into the coronary artery
- the insertion of a wire mesh tube to prop open a blocked blood vessel during an angioplasty
- bypass surgery, which involves a surgeon creating new pathways for blood to travel through to the heart muscle
- ablation, which is a treatment that destroys certain heart cells using radio waves
To minimize the risk of further heart attacks, a doctor will usually recommend lifestyle changes, such as quitting smoking, losing weight, getting more exercise, and eating a more nutritious diet.
A person will likely receive different treatments if their high troponin levels are due to a different cause.
A troponin test can help detect an injury to the heart. A doctor may order the test if a person is experiencing symptoms that indicate a possible heart attack, such as:
- chest pain
- shortness of breath
- a rapid heart rate
A doctor will not use elevated troponin levels to diagnose a heart condition. They will also consider the person’s other symptoms and may use other diagnostic tools, such as a physical examination or an electrocardiogram (EKG).
Troponin testing, however, allows a doctor to assess the extent of any heart damage, which can guide treatment decisions and help determine whether current treatments are effective.
A troponin test is a simple blood test, and blood tests are generally very safe and quick.
A healthcare professional will usually take the blood sample from the arm. They often do this by first wrapping a band around the person’s upper arm. Tightening this band causes the blood vessels to swell, making it easier to draw the blood.
The healthcare professional will then insert a needle into a blood vessel and withdraw some blood. The needle may cause a short, sharp sensation, but many people feel little or no pain.
A person needs to inform the healthcare professional if they feel dizzy or nauseous after giving the sample. Sitting for 5–10 minutes and drinking a glass of water or sugary juice can help relieve dizziness and nausea.
A doctor may sometimes request additional blood samples over a few hours.
Doctors use troponin tests to assess whether there is damage to a person’s heart. Very high levels of troponin can indicate a recent heart attack.
Doctors usually order troponin testing if they suspect that a person has had a recent heart attack. Higher-than-normal levels of troponin can also indicate other injuries and conditions that affect the heart.
However, doctors do not use elevated troponin levels alone to diagnose a heart condition. They will also take into account the person’s other symptoms and may order further tests, such as an EKG.
The best treatment for high troponin levels will depend on the underlying cause. If a heart attack is responsible for the high levels, treatment may involve emergency procedures to open a blocked artery.