Heart calcium scan most effective predictor of heart disease risk

by Bruce Sylvester – take from The Journal of the American Medical Association (JAMA) –

Among patients classified at intermediate risk, heart calcium scanning, known as coronary artery calcium (CAC),  is the best assessment tool for predicting the development of cardiovascular disease. Researchers reported this finding in the Aug. 22, 2012 issue of the Journal of the American Medical Association.

As background, the authors noted that current guidelines classify individuals as high, intermediate or low risk using the Framingham Risk Score (FRS), a cardiovascular risk-prediction model. But the intermediate group includes both persons who could benefit from drug therapy and persons who can be managed with lifestyle measures.

“We know how to treat patients at low and high risk for heart disease, but for the estimated 23 million Americans who are at intermediate risk, we still are not certain about the best way to proceed,” said lead author Joseph Yeboah, M.D., Assistant Professor Internal Medicine-Cardiology at Wake Forest Baptist Medical Center , Winston-Salem, North Carolina.

Evaluating relative improvements in various testing modes, especially when used in conjunction with the FRS, could help identify intermediate-risk persons who might benefit from more aggressive primary prevention interventions, including the use of aspirin and the setting of lower targets for drug treatment of LDL cholesterol and blood pressure, Yeboah added.

For this retrospective study, the investigators took data from the NHLBI’s Multi-Ethnic Study of Atherosclerosis (MESA) study, and they made a head-to-head comparison of six top assessment tests for cardiovascular risk prediction in intermediate-risk people: CAC score, ankle-brachial index, brachial flow mediated dilation, carotid intima-media thickness, high sensitivity C-reactive protein and family history of heart disease.

From a total of 6,814 MESA subjects, 1,330 were deemed to be at intermediate risk and were included in the study.

Among the intermediate-risk subjects, the investigators reported that the CAC score was the best predictor of who would develop heart disease in the ensuing 7.5 years (average) of follow-up observation.

“If we want to concentrate our attention on the subset of intermediate-risk patients who are at the highest risk for cardiovascular disease, CAC is clearly the best tool we have in our arsenal to identify them. However, we have to look at other factors such as costs and risks associated with radiation exposure from a CT scan before deciding if everyone in the intermediate group should be screened,” Yeboah said.