The cholesterol artery test is a scan that can help show a person’s risk of heart disease. The scan lets doctors check for the buildup of plaque in the blood vessels that feed the heart.

Heart disease is a leading cause of death in the United States. Many factors can contribute to a person’s heart disease risk. A key heart disease risk factor is a high level of a fatty, waxy substance known as cholesterol in the blood. It can accumulate in blood vessels.

A cholesterol artery test is a noninvasive test that can check the health of a person’s arteries. As such, this test can help estimate the potential risk of heart disease and help at-risk individuals take life-saving measures to prevent heart problems as soon as possible.

Read on to learn more about the cholesterol artery test.

A nurse taking a blood sample-1.Share on Pinterest
Johner Images/Getty Images

The cholesterol artery test is a type of computerized tomography (CT) scan. It is also known as a coronary artery calcium (CAC) test.

A CT scan is a type of imaging in which a computer takes multiple X-ray images and quickly moves around the body, providing a detailed, 3D picture. For a CAC scan, the images are of the coronary arteries around the heart. The doctors are checking for a substance known as calcified plaque.

High cholesterol levels can contribute to plaque, which builds up along the walls of major blood vessels. This narrows the blood vessels, meaning the heart has to work harder to move blood around the body. A CAC test allows doctors to measure and rate how much plaque has built up in the coronary arteries.

The CAC test takes multiple images of the coronary arteries. These images show the buildup of calcified plaque. This hard substance consists of cholesterol, fats, and a form of calcium that is different from the calcium in bone tissue.

The procedure does not involve any special preparation. It uses a type of CT machine known as a multidetector CT (MDCT). The whole procedure lasts around 10–15 minutes.

When a person goes to receive a CAC test, the doctor attaches electrodes to their chest. This helps them measure the electrical activity of the heart (an electrocardiogram, or ECG) and supports the creation of clear images in the MDCT.

The table slowly rotates inside the MDCT. The scanner will not touch the individual. A technician observes the whole process and can communicate with the individual in the scanner using an intercom. They may request that the person receiving the scan hold their breath briefly.

Not every insurance provider pays for the test, which can cost around $100–$400.

The CAC test could be particularly helpful for the following groups of people, according to the American Heart Association (AHA):

  • people who do not wish to start statin therapy without having a clearer understanding of their risk of cardiac events and the benefits of reducing cholesterol levels
  • people who have stopped statin therapy due to side effects and have concerns about restarting
  • males aged 55–80 years and females aged 60–80 years who do not have many risk factors for heart disease and do not know if they would benefit from using statins
  • people who are between 40 and 55 years of age and have a 5–7.5% estimated risk of developing heart disease in the next 10 years or several risk factors for heart disease

Statins are a type of medication for reducing cholesterol and preventing heart disease. People whose doctors are recommending statins or who used to take statins for high cholesterol may benefit from asking their doctor about a CAC test.

However, not everyone will benefit from a CAC test as a routine screening. It will not provide extra information for those who have already had a heart attack, bypass surgery, or a coronary stent.

Symptoms of heart disease, a family history of coronary artery disease at a young age, and a suspected heart attack risk make a person a candidate for a CAC test.

After the test, a doctor provides a CAC score. There are different ways of interpreting a CAC score, according to a 2021 review.

However, in general:

  • A score of 0: This means there is no plaque and a very low risk of severe cardiac events in the future.
  • 1–10: Minimal plaque has appeared on the scan. There is a low risk of severe cardiac events.
  • 11–100: The arteries have become mildly stiff. A person with this score has a mild risk of coronary artery disease.
  • 101–400: A person with this score has a moderate risk of severe cardiac problems in the future. Those with a score above 100 are good candidates for taking statins, according to the AHA.
  • Over 400: An individual with a CAC score of over 400 has a significant risk of a future cardiac event.

Several studies have found that a high CAC score suggests a higher risk of mortality than high cholesterol. For example, a 2019 review suggests that an individual with high cholesterol but a CAC score of zero is unlikely to have a cardiac event related to hardened arteries for the next 5 years.

More commonly, a doctor will test cholesterol levels using a simple blood draw. This may involve not eating or drinking for 8–12 hours before the test.

According to the Centers for Disease Control and Prevention (CDC), most people without medical issues should receive a cholesterol check every 4–6 years. Those with a family history of high cholesterol, diabetes, or heart disease should get more frequent checks.

Understanding cholesterol levels is important, but it is just one factor of heart disease risk and overall health. A healthcare professional may request a CAC test after testing cholesterol another way in order to gain a deeper understanding of a person’s heart disease risk.

A cholesterol artery test, or coronary artery calcium test, can help a person understand their risk of serious heart problems. It shows CT images of plaque on the walls of a person’s coronary arteries.

This test can also guide a healthcare professional in recommending whether or not a person should start or continue taking medications, such as statins.

Other cholesterol tests are available, including blood tests. However, a cholesterol artery test can more accurately show cardiovascular disease risk.