London, July 28 - Researchers may be able to predict future severe cardiac events in patients with known, stable coronary artery disease (CAD), by measuring calcium levels, according to a new study.

CAD is a condition in which plaque, consisting of cholesterol, calcium, fat and other substances, builds up inside the arteries that supply blood to the heart.

When plaque builds up in the coronary arteries, blood flow to the heart is reduced and may lead to arrhythmia (irregular or erratic heart beats), heart attack or heart failure.

'The amount of calcium in the coronary vessels, as measured by CT (computed tomography), is of high predictive value for subsequent serious or fatal heart attack in these patients,' said the study's lead author, Marcus Hacker.

Hacker is assistant medical director at Ludwig Maximilians University (LMU) Munich, Germany.

CAD is the most common type of heart disease. According to the National Heart, Lung and Blood Institute, it is the leading cause of death in the US for both men and women, killing more than 5,00,000 Americans each year.

Single photon emission computed tomography (SPECT) imaging is a nuclear medicine diagnostic procedure that provides excellent 3-D images of the coronary arteries to assist in the diagnosis and treatment of CAD.