Key Points

• A coronary calcium scan is a test that can help show whether you have coronary artery disease (CAD).
• Coronary calcium scanning looks for specks of calcium (called calcifications) in the walls of the coronary arteries. Calcifications are an early sign of heart disease.
• This test is most useful for people who are at moderate risk for a heart attack. You or your doctor can calculate your 10-year risk using the Risk Assessment Tool from the National Cholesterol Education Program. People at moderate risk have a 10 to 20 percent chance of having a heart attack within the next 10 years.
• The coronary calcium scan may help doctors decide who within the moderate risk group needs treatment.
• No special preparation is needed before a coronary calcium scan.
• Coronary calcium scans are done in a hospital or outpatient office. The x-ray machine that’s used is called a computed tomography (CT) scanner.
• A coronary calcium scan takes about 5 to 10 minutes. During the scan, you will lie quietly on your back, while the CT scanner takes pictures of your heart.
• You’re able to return to your normal activities after the scan is done.
• The test is negative if there are no calcifications in your coronary arteries. This means your chance of having a heart attack in the next 2 to 5 years is low.
• The test is positive if calcifications are found in your coronary arteries. Calcifications are a sign of atherosclerosis and CAD.
• After the scan, you will receive a calcium score called an Agatston score. The higher the score, the greater the amount of atherosclerosis or plaque buildup.
• Use this calculator (from the National Heart, Lung, and Blood Institute) to see whether your Agatston score is high.
• Coronary calcium scanning has very few risks. The test usually isn’t invasive, which means that no surgery is done and no instruments are inserted into your body. Coronary calcium scan doesn’t require the injection of contrast dye to make your heart or arteries visible on the x-ray images. If you need medicine to slow down your heartbeat during the scan, it may be injected into a vein.
• Because an x-ray machine is involved, you will be exposed to a small amount of radiation. The amount of radiation is less than or equal to the amount of radiation you’re naturally exposed to in a single year.