|Definition: Also called coronary calcium scan, coronary artery calcium scoring and electron beam computed tomography (EBCT).
What Is A Calcium Score Test?
It is a test that scans for tiny specks of calcium on the walls of the arteries that supply blood to the heart (coronary arteries). Your doctor will refer to these specks as calcifications. In healthy people, there should be no sign of calcifications. If there is, it is considered one of the early signs of coronary heart disease (CHD). The more calcifications present, the higher your calcium scoring, and the higher your risk of a future heart attack.
The calcium itself is not really the problem. However, where there is calcium knocking about, there is likely to be atherosclerosis some where in one of the miles of blood vessels that run through the body. Atherosclerosis refers to the build up of fatty deposits (or plaques) that can eventually block an artery or form a traveling clot leading to a heart attack or stroke. In other words, calcium is a marker for atherosclerosis.
Who Has It?
Typically the type of person who seeks this test is curious about their risk of heart disease but they don't have any symptoms of heart problems (such as chest pain called angina). If you have symptoms then different heart disease tests are more appropriate such as an exercise stress test, echocardiogram and so on.
Candidates for this test include:
• People with mild hypertension or raised cholesterol (borderline for considering cardiac prevention therapy) and who are undecided about taking necessary prevention medication. They may use the scan result to decide whether or not to commit to therapy.
• People with a family history of CHD may benefit from regular screening. If premature CHD is detected it can be treated early.
• Patients with cardiomyopathy may benefit from knowing if they have underlying CHD. If the calcium score is zero it implies that the cardiomyopathy is viral, idiopathic (unknown cause) or metabolic origin rather than ischemic (restriction of blood flow to the heart). As a result, coronary angiography could be avoided.
• It could provide initial screening for younger patients with chest pain (to rule out heart disease which is less likely to exist in younger people) - as a way to avoid more costly tests such as angiography.
How Is The Test Performed?
The test is performed by CT scan. On the day of your scan, a blood test may be taken to test your cholesterol levels (blood lipid levels). A nurse will take your blood pressure and record your weight and height. You will need to change into a hospital gown and then will be taken to a special X-ray room. You will be asked to lie on a special scan table. Small sticky electrode patches are attached to your chest so that your heart rate can be monitored by an electrocardiogram (EKG). Next, the table will move and you find yourself in a donut-shaped scanner. The CT scan takes lots of images of your heart and arteries. The scan only takes a few minutes and is completely painless. Your chest pain center should be able to discuss your results the same day.
What Do My Calcium Score Test Results Mean?
|Your Calcium Score
||How much plaque is present
||Chance that you have coronary heart disease
||Risk of a heart attack
||Less than 1 percent. Highly unlikely.
||Your 10 year risk is less than 2 percent. The annual rate of heart attack is less than 0.11 percent.
||Your doctor should still discuss heart disease risk factors. Repeat screening every 5 years is enough.
||Small bit found.
||The annual rate is double the previous group: 0.2 percent.
||Lifestyle modifications are recommended. See CHD prevention. Repeat scan every 2 to 5 years.
||Moderate atherosclerotic build up.
||Non-obstructive CHD likely (symptoms such as chest pain are reported but no sign of blocked arteries), although obstructive disease (blocked arteries) is possible.
||Annual rate of 1 percent.
||Should be treated with secondary prevention guidelines of the American Heart Association. This can include taking daily medications (statins, aspirin therapy and possibly ACE inhibition) to lower blood pressure and/or cholesterol levels. Repeat scan annually.
||Extensive atherosclerotic build up.
||High likelihood that at least one artery is blocked with plaque (stenosis).
||Annual rate is 4.8 percent. Your 10 year risk ranges from 20 to 70 percent.
||Should be treated with secondary prevention guidelines of the American Heart Association. This can include taking daily medications to lower blood pressure and/or cholesterol levels. Repeat scan annually. You should also be tested (stress test) for inducible ischemia (inadequate supply of oxygen to the heart via blood flow).
Note 1: Annual scans are recommended for those with high calcium scores. This is because those with scores that increase more than 15 percent a year are at increased risk for coronary events and require a change in their treatment plan.
Note 2: Patients with calcium scores over 600 have an extremely high risk of a heart attack (15 percent in a year) and should be referred to a cardiologist for treatment.
The calcium score test (with CT scan) is an excellent tool for accurately and noninvasively screening for CHD in asymptomatic people. It allows doctors to calculate your risk of a heart attack over time so they can tailor prevention goals and determine if further tests and follow up are needed. Repeat tests allow for monitoring of changes in the plaque and the effects of any treatment. The calcium score is also a a powerful motivational tool for those considering lifestyle changes and medical treatment.
This test cannot locate or judge the severity of any blocked artery, and thus is not a substitute for stress testing or angiography. The diagnosis of CHD still requires stress testing or angiography.
In some instances a person may have calcium in their arteries but not have CHD. This is more likely to occur in those with low CHD risk factors.
How Much Does It Cost?
The examination costs about $400. This includes fees for the scan itself and any blood tests and consultations. As it is a screening test it not covered by most insurances companies, so you are likely to liable to pay the full cost.