Coronary arteries supply the heart muscle with oxygen-rich blood. Coronary artery disease is a condition in which fat, cholesterol, calcium and other substances in the blood build up inside the coronary arteries, forming plaque. Scientists have recently found that in addition to the traditional risk factors for coronary heart disease, calcium in the blood is an important contributor to this process, which is known as atherosclerosis.
How Atherosclerosis Develops
Healthy arteries are strong and flexible, but MayoClinic.com explains that as a person ages, deposits of fatty substances, cholesterol, cellular waste products and calcium accumulate in the inner lining of arteries. This material thickens and hardens, forming structures called plaques, which can make the arteries narrower and less flexible. This reduces blood flow to the heart muscle. When a plaque ruptures, it causes blood clots to form in the arteries, blocking blood flow and causing a heart attack.
Calcium Contributes to Coronary Artery Disease
While heart researchers have long known that deposits of fatty substances known as lipids, cholesterol, cellular waste products and other substances accumulate in the inner lining of arteries and lead to atherosclerosis, they have been searching for other factors that contribute. They have discovered that calcium in the blood is an important building block in forming the plaques that accumulate within blood vessel walls. As the atherosclerotic process progresses, the amount of calcification increases, promoting the formation of coronary plaques.
Calcium Supplements Shown to Increase Heart Attack Risk
A review of research shows that calcium supplementation, without taking vitamin D at the same time, appears to increase the risk of heart attack. A meta-analysis published in the "British Medical Journal" analyzed 15 clinical trials involving almost 12,000 patients, the large majority of whom were older women being treated for osteoporosis. The meta-analysis revealed that those who took 500 mg per day or more of calcium supplements were about 30 percent more likely to have a heart attack than those who did not. Calcium taken in food sources, however, did not contribute to increased risk of heart attack.
Calcium Score Screening Scan
A coronary calcium score screening scan is a noninvasive test that detects calcium deposits in the coronary artery walls. According to the National Heart, Lung and Blood Institute, the test is performed with an electron beam CT scanner (EBCT) or a multi-detector computed tomography (MDCT) scanner that detect the presence, location and extent of calcium deposits in the coronary system. The quantity of coronary artery calcium predicts the likelihood of developing future cardiovascular events. The scan can show whether a person is at increased risk for a heart attack or other heart problems before other symptoms occur.
Calcium Screening is a Good Predictor of Heart Disease
Doctors were initially skeptical as to whether the addition of a patient's coronary artery calcium (CAC) score to traditional heart risk factors would change heart-risk classification. What researchers found was that the addition of a CAC score led to significantly better prediction of heart events than traditional factors alone. According to Articlesbase, adding CAC scores moved 25 percent of patients into a different risk group than where they were placed based on traditional risk factors.
