Researchers report that news in tomorrow's edition of The New England Journal of Medicine.
The coronary arteries supply oxygen-rich blood to heart muscle. In coronary artery disease, plaque builds up inside coronary arteries' walls, narrowing the arteries. Calcium is one of the components of plaque. The more plaque that is present, the more calcium is present in the walls of heart arteries. So measuring coronary calcium can be used as a surrogate for measuring plaque.
Coronary calcium measurements are derived from computed tomography (CT) scans of the heart and are quantified into "scores." Coronary calcium scores aren't new. But previous research has shown that whites have higher coronary calcium scores than minorities. That's where the new study comes in.
Coronary Calcium Scores
The researchers asked whether coronary calcium scores predicted heart "events" -- heart attack, death from coronary heart disease, or chest pain (angina) -- in whites, African-Americans, Chinese, and Hispanic adults.
The study included more than 6,700 U.S. adults with no history of heart disease.
When the study started, participants were 45-84 years old; on average, they were in their 60s. They got CT heart scans and were told whether their coronary calcium score was negative, low, average, or greater than average. They were also advised to talk to their doctor about their test results.
As in other studies, whites tended to have higher coronary calcium scores. But in all ethnic groups, people with higher coronary calcium scores were more likely to have heart "events" during the study.
For instance, someone with a coronary calcium score of 101-300 was more than seven times as likely to experience a heart "event" than someone with no evidence of coronary calcium.
There are other well-known risk factors for heart disease, including smoking, obesity, poor cholesterol profiles, and family history of heart disease. Coronary calcium scores add more information on the patients' risk, note the University of California at Irvine's Robert Detrano, MD, PhD, and colleagues.
Because relatively few people in their study had heart "events," follow-up studies are needed. Detrano's team also notes that some people may have been inspired to upgrade their heart's health when they got their coronary calcium scores at the study's start.
"Is this relatively small improvement in accuracy worth it? Does calcium scoring provide value? Here the issue is uncertain," states an editorial published with the study.
Coronary calcium scoring "remains an interesting technique" and studies of its cost-effectiveness should be done, write the editorialists, who included William Weintraub, MD, of the Christiana Care Health System in Newark, N.J.