Calcium in Arteries May Predict Heart Risk
Study Shows a Calcium Score May Be Helpful Tool in Predicting Heart Disease
April 27, 2010 -- Doctors who use CT scans to detect calcium buildup in arteries may be able to better predict heart disease risk in some of their patients, a new study suggests.
Calcium deposits in the walls of arteries are part of the process of accumulating plaque, called atherosclerosis. The amount of calcium in artery walls is proportional to the amount of plaque present and is reported as a "calcium score."
Calcium accumulation is an early sign of coronary artery disease and usually precedes the development of actual blockages. However, whether knowing the calcium score (above and beyond traditional risk factors) improves predicting who is at high risk for heart disease is not clear.
Calcium Score and Heart Disease
In the new study, 5,878 patients between 45 and 84 enrolled in the Multi-Ethnic Study of Artherosclerosis (MESA Trial) were evaluated using CT scans to look for calcium in the walls of their coronary arteries.
The participants did not have known cardiovascular disease at the start of the study. The participants included men and women who identified themselves as white, black, Hispanic, or Chinese. They were followed by telephone interviews every nine to 12 months to gather information about hospital admissions, other heart disease events, and death.
Over a follow-up period of almost six years, 209 participants experienced a heart disease event, such as heart attack, death from heart disease, or cardiac arrest.
By using the CT-derived calcium score in addition to other risk factors, researchers were able to correctly place 77% of the overall study population into high- or low-risk categories. When calcium scores were not included, only 69% of participants were correctly classified.
CT Scan Not Recommended
The researchers say that coronary calcium scores helped reclassify a notable number of patients into more accurate risk categories. Twenty-three percent of patients who experienced events were reclassified to a higher risk category, and an additional 13% who did not experience an event were reclassified as low risk based on CT results.
The researchers conclude that a calcium score, used in conjunction with known risk factors, is likely to improve the ability of doctors to determine if their patients are at risk for developing heart problems over time.