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!
Artificial intelligence may help diagnose tuberculosis in remote areas
25.04.2017 | Radiological Society of North America
Pharmacoscpy: Next-Generation Microscopy
25.04.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Materials Sciences
26.04.2017 | Agricultural and Forestry Science
26.04.2017 | Physics and Astronomy