Coronary Artery Calcium Test

What is a Coronary Artery Calcium Test?

A coronary artery calcium (CAC) test is a kind of heart scan. X-rays take detailed images of the arteries that supply blood to the heart muscle. The images show any calcium deposits in your coronary arteries. Higher calcium scores usually mean more calcium buildup in the heart arteries and a higher future risk of heart disease.

See an illustration of coronary arteries

Why do people have it done?

A CAC test measures the calcium buildup in your heart arteries. The test can help your healthcare team:

• See how much plaque is in your heart arteries and how much calcium has built up
• Better understand your future risk of heart disease
• Decide whether preventive treatment, such as statin therapy, may be helpful

CAC testing can help people and their healthcare team make prevention decisions, especially when the next steps are unclear.

CAC testing may be useful for people who:

• Are unsure about starting a statin
• Are considering restarting statin therapy after stopping it because of side effects
• Want more information about their heart disease risk

Who is not a good candidate for CAC?

• People with a very low risk of heart disease
• People whose treatment plan is already clear
• People having symptoms, such as chest pain, who need other kinds of testing
• People who already have known heart artery disease or who have had a heart attack, bypass surgery or a stent

What are the risks of the CAC scan?

CAC scanning uses a low dose of radiation. The amount can vary by scanner and protocol, so patients should discuss risks and benefits with their clinician.

Tell your healthcare team if you’re pregnant. Because the test uses radiation, it may be delayed until after your pregnancy.

How do I prepare for the scan?

No special preparation is needed.

What happens during the test?

Technicians perform the CAC scan in hospitals or special outpatient clinics.

• Electrodes are attached to your chest to monitor your EKG. The EKG also helps the computer create clear pictures of your heart.
• When you’re ready, the table slowly moves inside the machine. The scanner arches around you but doesn’t touch you.
• The technician will watch you closely through a window. You can talk to them through an intercom.
• The technician will ask you to hold your breath for short periods.
• CT scanning takes about 10-15 minutes.

Are CAC scans covered by insurance?

Insurance may cover the test. If not, out-of-pocket costs typically range from $50 to $250.

What happens after the CAC scan?

Your healthcare team will make an appointment to discuss the results and next steps with you.