It may give doctors new tool in treating and managing heart disease, experts say
TUESDAY, April 27 (HealthDay News) -- Adding a computed tomography test to measure calcium in coronary arteries improves predictions of future heart disease, a new study finds, but no one knows yet whether it's worth the cost and risk due to radiation exposure.
"This kind of evidence gives encouragement to go on and do additional testing, but it shouldn't convince us that this test should be done routinely," said Dr. Philip Greenland, a professor of preventive medicine at Northwestern University Feinberg School of Medicine, and a member of the team reporting the study in the April 28 issue of the Journal of the American Medical Association.
Computed tomography uses X-rays to get a detailed picture of heart structure. Its use in diagnosing existing heart disease has become controversial because X-ray exposure increases the risk of cancer. The new study of nearly 6,000 healthy Americans was done to see whether the technique could improve the predictive power of existing cardiac risk factors such as high blood pressure, high cholesterol and obesity.
The study began in July 2000 and ran through May 2008. It used two models to predict the five-year risk of a heart attack, resuscitated cardiac arrest or death from coronary heart disease: the traditional risk factors; or those risk factors plus the coronary artery calcium score.
At 5.8 years, the participants had experienced 209 coronary heart disease problems and 122 "major events" -- that is, heart attacks, deaths from coronary heart disease, or cardiac arrest followed by a resuscitation.
The second model, which used the regular risk factors plus the calcium scan, was able to predict an additional 23 percent of the participants who would go on to experience a harmful cardiovascular event. In addition, 13 percent the model reclassified as low-risk did not experien
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