The calcium score test is a noninvasive procedure using computed tomography to measure the quantity of calcium deposits in the heart, especially deposits in the coronary arteries. An increase in deposits contributes to narrowing in the arteries and a reduction in heart function, which can lead to a heart attack. The larger the number of deposits the greater the likelihood of a future serious cardiac event. Calcium score testing is considered a more accurate predictor of coronary artery disease than standard cholesterol screening tests.
Cardiac Calcium Scanning
The number and density of calcium deposits in the coronary arteries are calculated and evaluated by a radiologist using computerized images to arrive at a test score. The deposits are called calcifications, which are an early sign of heart disease. Computed tomography produces high-speed, multiple images that are synchronized with the heartbeat using a continuous electrocardiogram. Continuous cardiac monitoring allows the images to be taken when the heart is at rest and the coronary vessels are relaxed.
Plaque formation in blood vessels is a result of materials from the bloodstream depositing along the vessel wall, causing it to thicken, narrow and eventually obstruct blood flow. Composition of plaque can include fat, calcium and cholesterol as well as other materials in the bloodstream. With computed tomography images, calcium plaques emerge as luminous specks varying in size with the amount of calcium present. Not all plaques contain calcium and are classified as soft plaques, which are not detected with the calcium score test.
Computerized tomography scanning is the most precise equipment for determining the location of calcium deposits before an individual experiences symptoms of heart disease. Facilities can choose between two types of scanners. One is the electron beam computed tomography or EBCT, and the other is the multidetector computed tomography or MDCT. Detailed images of the heart are taken with either machine and both machines use X-rays. Exposure to radiation is minimal with the EBCT, using less radiation than the MDCT. The test takes approximately 10 minutes.
Heart disease is the leading cause of death for men and women in the United States. Risk factors for developing heart disease include a family history of coronary artery disease, males over 45 years of age, females over the age of 55, a smoking history, elevated cholesterol levels, hypertension, diabetes, excess weight and a sedentary lifestyle.
Preparation for the test is minimal but some facilities require a lipid analysis or lipid profile blood test just before the test. The lipid profile or analysis requires a 12-hour fast before the test but sips of water are allowed when taking medications. Caffeine and nicotine constrict vessels and might be restricted for four hours before the test. The test is not recommended if you are pregnant or unsure of an existing pregnancy because of the radiation exposure.