MONDAY, May 12, 2003 (HealthDayNews) -- Put to the test, an imaging device called an electron beam computed tomography did warn of future cardiovascular trouble in healthy, seemingly trouble-free individuals.
"Half of deaths due to heart disease occur in people with no symptoms," says a statement by Dr. George T. Kondos, head of the team that did the test. "And a third of people with heart disease don't have any of the traditional risk factors -- diabetes, high blood pressure, high cholesterol, family history or peripheral vascular disease. Those individuals would go undetected by traditional screening methods."
Electron beam computed tomography (also known as EBCT or EBT) detects a different source of trouble -- calcium deposits in artery walls that can eventually be blocked, causing a heart attack or stroke. It is a fast form of X-ray imaging technology that can be done in a few minutes. And the amount of those calcium deposits did predict trouble, says a report in the May 13 issue of Circulation.
More than 5,600 men and women were given the test by Kondos, who is an associate professor of medicine at the University of Illinois' College of Medicine in Chicago. They were divided into four groups, depending on the extent of calcium deposits found by an EBCT scan.
Over the next three and a half years, men in the highest quarter of calcium scores were 2.3 times more likely to die or have a heart attack and 10.1 times more likely to have bypass surgery or artery-clearing angioplasty than those in the lowest quarter, the report says. There were no comparable figures on deaths and heart attacks for women, because few of them occurred, but the incidence of bypass surgery or angioplasty was 3.6 times higher for those in the highest quarter compared to those in the lowest.
"This is an important advance in the study of this technology," says Dr. Patrick G. O'Malley, an EBCT expert and chief of the division of general and internal medicine at Walter Reed Army Medical Center in Washington, D.C.
The research helps resolve a running debate on EBCT's effectiveness. "It is an open question whether it can predict over and above the conventional risk factors," O'Malley says.
O'Malley led a recently published study showing that EBCT readings must be followed up by doctors to make sure persons with high scores pay careful attention to the conventional risk factors to prevent heart attack and stroke
EBT is not for everyone, says Dr. William Weintraub, a professor of medicine at Emory University and author of an accompanying editorial.
"It is most appropriate for people at an intermediate level of risk," Weintraub says. Physicians must use judgment in selecting those individuals because there is "a tremendous range within the category of medium-risk individuals," he adds.
Whether EBT is cost-effective is a question that still has to be answered, Weintraub says: "In the meantime, until we learn more, it won't do any harm and may help, although it does cost money."