Screening tool may better identify heart disease in African-Americans

Nov 30, 2010

In a study being presented today at the annual meeting of the Radiological Society of North America (RSNA), researchers say they may have an explanation as to why African Americans, despite having lower amounts of coronary artery calcification, are at increased risk for heart attacks and other cardiovascular events compared with Caucasians.

The answer, according to researchers at the Medical University of South Carolina (MUSC) in Charleston, S.C., may be increased levels of non-calcified , which consists of buildups of soft deposits deep in the walls of the arteries that are not detected by some cardiac tests. Non-calcified plaque is more vulnerable to rupturing and causing a blood clot, which could lead to a or other .

"The African Americans and Caucasians we studied had approximately the same amount of plaque in their arteries, but different kinds of plaque," said John W. Nance Jr., M.D., researcher in the Department of Radiology and Radiological Sciences at MUSC.

Calcium scoring with CT is a common for patients at risk for cardiovascular disease, because increased calcification in the coronary arteries correlates with a greater risk for a heart attack or other cardiovascular event. However, calcium scoring does not detect non-calcified plaque.

Dr. Nance and a team of researchers compared 301 patients who underwent two types of CT imaging for acute chest pain: calcium scoring, in which the amount of calcified plaque in the coronary arteries is measured, and contrast-enhanced angiography (cCTA), which provides a more comprehensive picture of the arteries, including the presence of non-calcified and mixed plaques.

The study group comprised 50 percent each of African American and Caucasian patients, 33 percent of whom were male (mean age 55).

Calcium scoring revealed that calcified plaque was much more prevalent in the coronary arteries of Caucasian patients than in the African Americans (45 percent, versus 26 percent). The cCTA revealed that, compared with Caucasians, African American patients had a significantly higher prevalence of non-calcified plaque (64 percent, versus 41 percent), and more of it. The median volume of non-calcified plaque among the African American patients was 2.2 milliliters (mL), compared with 1.4 mL among Caucasians.

"This study confirms that the disease pathways that lead to acute cardiovascular events are different for Caucasians and African Americans," explained coauthor U. Joseph Schoepf, M.D., professor of radiology and medicine and director of cardiovascular imaging at MUSC. "Coronary CT angiography is an effective and noninvasive tool for studying the pathology of atherosclerosis among different ethnicities."

According to Dr. Nance, further research is warranted to determine whether non-calcified plaque detection can improve cardiovascular risk prediction for African Americans. In the meantime, the value of calcium scoring as a for this patient group should be reinterpreted.

While cCTA does expose patients to ionizing radiation, according to Dr. Schoepf, the effective dose of this procedure has been considerably reduced over the past few years, making it a viable screening option.

"For African American patients, coronary CT angiography may be a more appropriate screening tool for cardiovascular risk," he said.

Explore further: Education, breastfeeding and gender affect the microbes on our bodies

add to favorites email to friend print save as pdf

Related Stories

Coronary calcium distribution tied to heart attack risk

May 27, 2008

A new calcium scoring method may better predict a person’s risk of heart attack, according to a new multicenter study published in the June issue of the journal Radiology. Calcium coverage scoring takes into account not on ...

Imaging fat layer around heart can help predict disease

Mar 15, 2010

Imaging epicardial adipose tissue, or the layer of fat around the heart, can provide extra information compared with standard diagnostic techniques such as coronary artery calcium scoring, according to research by cardiologists ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

Treating depression in Parkinson's patients

A group of scientists from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging has found interesting new information in a study on depression and neuropsychological function in Parkinson's ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.