Calcium build-up predicts heart attacks

NEW YORK (Reuters Health) - The presence of calcium in the coronary arteries, which can be determined with a special CT scan, can identify individuals who despite having no symptoms are likely to suffer a heart attack in the future, according to findings published in the American Heart Journal.

Dr. Alexander Becker and colleagues from Ludwig-Maximilians-University, Munich, examined whether coronary calcium build-up could predict heart attacks and cardiac-related death in 1,726 individuals with no symptoms. The average age of the study participants was 58 years old and the average follow-up period was 40 months.

Using electron beam CT, a type of X-ray test developed specifically to capture images of the heart, the researchers were able to not only determine the presence of calcium in the coronary arteries, but also the amount. Prior research has shown that coronary calcium gives a rough indication of the extent to which the arteries are narrowed, which is critical in determining the risk of heart attack.

Coronary calcifications were excluded in 379 subjects. A total of 724 patients had significant calcium build-up, defined as a score above the 75th percentile on special scoring system called the Agatston scale.

Overall, 114 patients experienced a heart attack and 66 patients died from heart-related causes.

No cardiac events were seen in patients without coronary calcium build-up. By contrast, people with an Agatston score above the 75th percentile were at increased risk for heart attack and death from heart-related causes.

Moreover, the researchers found that the Agatston score was more accurate than older risk-determining models in predicting these adverse outcomes.

SOURCE: American Heart Journal, January 2008.