High calcium level in arteries predicts heart attack

Updated: Jul 28, 2009, 00:00 AM IST

London: 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.

Currently, calcium scoring -- measuring the amount of calcium in the arteries -- is used as a screening exam and in cases of suspected CAD, but not in cases of known CAD.

Hacker and colleagues set out to determine if calcium scoring would lend additional
prognostic value to SPECT findings in patients with known, stable CAD.

The results, based on 260 CAD patients, showed that those with initial calcium score greater than 400 were at significantly increased risk for severe cardiac events.

"We found that coronary calcium seems to play an important role in predicting subsequent heart attack or sudden cardiac death, and adds prognostic value to SPECT findings," said co-author Christopher Uebleis, nuclear cardiologist at the LMU.

These findings were published online in Radiology.