High blood cholesterol is a major risk factor for heart disease. According to the Centers for Disease Control and Prevention, heart disease is a leading cause of death in the United States.

Cholesterol screenings can be a good indicator of your cardiac risk. This involves a blood test, which measures your blood cholesterol and determines your risk of heart disease.

However, another cholesterol screening called a coronary calcium test can offer detailed information about your cardiac risk. It’s also known as a:

  • coronary artery calcium test (CAC test)
  • cholesterol artery test
  • heart scan
  • calcium score

Read on to learn about how the test works, when it’s needed, and who should get one.

Coronary arteries bring blood to the heart. Healthy coronary arteries have a smooth inner lining, which allows for efficient, unobstructed blood flow.

But fatty deposits called plaque can accumulate in the arteries and reduce blood flow. This can lead to heart disease.

Arterial plaque is made of:

Since plaque contains both calcium and cholesterol, the presence of calcium in coronary arteries can indicate if there’s cholesterol present.

A computed tomography (CT) scan is used to perform a coronary calcium test. The test specifically measures the calcium in arterial plaque. It can help your doctor determine your risk of developing heart disease.

A coronary calcium test is a noninvasive test, meaning it’s a low risk screening.

The scan captures images of your coronary arteries, and the amount of calcium in each artery is measured. When the measurements are combined, the result is a total calcium “score.”

Your doctor will then compare this score with other people in your age group. A higher score may indicate a higher risk for heart disease.

A CT technologist performs the coronary calcium test, and a radiologist reviews and analyzes the results.

Steps involved in a coronary calcium test

  1. When you arrive, you’ll be asked to change into a gown. You’ll also need to remove any metal jewelry.
  2. Next, you’ll lie on your back on a CT table.
  3. The technologist will place electrodes on your chest to measure your heart rate.
  4. The CT machine will take images of your coronary arteries. You’ll be asked to stay still.
  5. The technologist might ask you to hold your breath for 20 to 30 seconds.
  6. The entire procedure will take about 10 to 15 minutes.

After the procedure is done, a radiologist will review the X-rays and send an analysis to your doctor. You will typically get the results in a few days.

A coronary calcium test isn’t recommended for everyone.

It’s best for people who are age 40 years or older who have a borderline to moderate risk of heart disease, according to the American College of Cardiology. Specifically, it’s recommended for those who are unsure if they will benefit from taking statins, a type of cholesterol-lowering drugs.

The test is also ideal for people who have stopped taking statins and want to determine if they should restart.

A coronary artery calcium test is not recommended for people who:

  • are younger than 40 years old
  • have a low risk of heart disease
  • already have heart disease

It’s important to note that the test is not a part of standard cholesterol screening. This means you won’t receive the test as part of your annual physical exam. If you believe you could benefit from this test, speak with your doctor about whether this procedure is right for you.

Coronary calcium test results indicate the amount of calcium in your arteries. It will involve a number known as a “score.”

The number is compared to the scores of people of the same age and gender. The higher the score, the higher the risk of heart disease.

Your doctor can determine the best course of treatment based on your score.

What does your score mean?

  • Zero: No plaque. A score of zero means there’s no plaque, meaning you have a low risk of heart attack.
  • 1–10: Small amount of plaque. This score indicates a heart disease risk of less than 10 percent.
  • 11–100: Some plaque. You have mild heart disease and are at a moderate risk for a heart attack. You’ll likely need to make some lifestyle changes, like quitting tobacco smoking if you smoke, eating nutrient-rich foods, and increasing physical activity.
  • 101–400: Moderate amount of plaque. You have a moderate to high risk of a heart attack. You’ll likely need to take statin therapy in addition to adopting lifestyle changes.
  • 401 or higher: Large amount of plaque. Your risk of having a heart attack is above 90%. You’ll need to take a statin.

It’s important to know that you can have a “zero” score and high blood cholesterol. That’s because the score simply indicates that there’s no calcified plaque buildup in your arteries. However, you can still have high cholesterol, which can eventually lead to plaque buildup.

In this case, your doctor may suggest lifestyle modifications to help reduce high blood cholesterol and prevent plaque buildup.

Getting tested is the only way to know if you have high cholesterol. That’s why regular cholesterol screenings are important, especially if you have other heart disease risks.

A standard cholesterol test is called a lipid panel. It involves a blood draw. This test does not measure your levels of coronary calcium, but it’s a good indicator of cardiac risk. It checks your levels of:

  • HDL (good) cholesterol: high-density lipoproteins that help transport and eliminate “bad” cholesterol
  • LDL (bad) cholesterol: low-density lipoproteins that build up and block blood vessels
  • triglycerides: a type of fat that stores unused calories
  • total cholesterol: the sum of HDL and LDL cholesterol plus 20% of triglycerides in the bloodstream

A coronary calcium test is a type of indirect cholesterol screening. It measures the amount of calcium in your arteries, which indicates the presence of cholesterol and plaque. It’s also known as a cholesterol artery test, heart scan, and coronary artery calcium scoring.

You might be a good candidate for the test if you are over 40 years old and have a borderline to moderate risk of heart disease. It can also help determine if prescription statins would be beneficial in lowering your cholesterol levels.

A higher calcium test score indicates a higher risk of heart disease. Your doctor can determine if you need the test and depending on the results, the best course of treatment.