(Ivanhoe Newswire)—Studies have shown that African Americans are at a greater risk of heart attacks, but what causes this? According to a recent study, African Americans have greater levels of non-calcified plaque consisting of buildups of soft deposits deep in the arterial walls. This type of plaque is more vulnerable to rupturing and causing blood clots which could lead to a heart attack or other cardiovascular event.

Joseph Schoepf, M.D., professor of radiology and medicine and director of cardiovascular imaging at Medical University of South Carolina in Charleston was quotes saying, “For a long time, physicians have searched for explanations as to why African Americans have higher rates of heart disease and higher cardiac death rates, but less coronary artery calcium than Caucasians. We show that one possible explanation for the discrepancy may be found in the higher rate of less stable, non-calcified plaque in the heart vessels of African Americans.”

Increased levels of calcified plaque in the coronary arteries generally correlate with a greater risk of heart attack or other cardiovascular events. For this study, researchers compared 301 patients who underwent both calcium scoring with CT, a common screening tool for patients at risk for cardiovascular disease, and a contrast-enhanced coronary CT angiography (cCTA). cCTA provides a more comprehensive picture of the arteries.

CT scanning, sometimes called CAT scanning, is a noninvasive medical test that scans the internal organs, bones, soft tissue and blood vessels and provides more clarity than regular x-ray exams. Angiography is a minimally invasive medical test that uses imaging technologies and, in some cases, a contrast material to produce pictures of major blood vessels throughout the body.
This study on calcium scoring was comprised 50 percent of African Americans and 50 percent of Caucasians, 33 percent of whom were males. Calcium scoring revealed that calcified plaque was much more prevalent in the coronary arteries of Caucasian patients than in African Americans. The cCTA revealed that, compared with Caucasian patients, many more African Americans had non-calcified plaque, and in greater amounts.

Dr. Schoepf was quoted saying, “The results of coronary artery calcium scoring studies are to be treated with caution in African Americans, because they may not reflect the true extent of cardiovascular disease. For African American patients, coronary CT angiography may be a more appropriate screening tool for cardiovascular risk.”

SOURCE: Radiology, June 27, 2011