The answer, according to researchers at the Medical University of South Carolina (MUSC) in Charleston, S.C., may be increased levels of non-calcified plaque, 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 heart attack or other cardiovascular event.
"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 screening tool 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 coronary CT 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 coronary artery 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 screening tool 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.
Other coauthors are Fabian Bamberg, M.D., J. Michael Barraza, B.S., Gorka Bastarrika, M.D., and Joseph Abro, M.A.
Note: Copies of RSNA 2010 news releases and electronic images will be available online at RSNA.org/press10 beginning Monday, Nov. 29.
RSNA is an association of more than 46,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
Editor's note: The data in these releases may differ from those in the published abstract and those actually presented at the meeting, as researchers continue to update their data right up until the meeting. To ensure you are using the most up-to-date information, please call the RSNA Newsroom at 1-312-949-3233.
For patient‑friendly information on CT angiography, visit RadiologyInfo.org
Linda Brooks | EurekAlert!
Surgery involving ultrasound energy found to treat high blood pressure
24.05.2018 | Queen Mary University of London
XXL computed tomography: a new dimension in X-ray analysis
17.05.2018 | Fraunhofer-Gesellschaft
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences