Nav: Home

Why do older asymptomatic patients have carotid imaging

April 18, 2016

Most of the patients who had carotid revascularization for asymptomatic carotid disease were diagnosed on the basis of carotid imaging tests ordered for uncertain or inappropriate indications, according to a new study published online by JAMA Internal Medicine.

Stroke is the fifth most common form of death and a major cause of disability among U.S. adults. As much as 15 percent of ischemic strokes are due to atherosclerosis (plaque buildup) of the carotid arteries. National guidelines do not agree on the role of carotid screening in asymptomatic patients who have no history of stroke or transient ischemic attack (TIA).

Salomeh Keyhani, M.D., M.P.H., of the University of California, San Francisco, and coauthors studied 4,127 Veterans Health Administration patients who were 65 or older and undergoing carotid revascularization for asymptomatic carotid stenosis between 2005 and 2009.

Indications for the carotid ultrasounds were extracted and the final study sample included 4,063 patients with an average age of more than 73, nearly all of whom were men and who had coexisting conditions including hypertension, diabetes and atrial fibrillation. The majority of patients (83 percent) received carotid endarterectomy (CEA); 16.8 percent received carotid stenting (CAS); and six patients did not have a medical record-confirmed revascularization within five years after first carotid imaging.

The study reports there were 5,226 indications for 4,063 carotid ultrasounds. The most common indications listed for carotid imaging were carotid bruit (30.2 percent of indications) and follow-up for carotid disease in patients who had previously documented carotid stenosis (20.8 percent of indications). Carotid bruit and follow-up for carotid disease accounted for 51.2 percent of the indications. Carotid bruit is a swishing sound that can be heard in the artery on physical exam as the blood tries to get around a blockage.

Based on indications, the rate of appropriate imaging was 5.4 percent; uncertain imaging was 83.4 percent; and inappropriate imaging was 11.3 percent, according to the results.

The most common appropriate indication listed for carotid imaging was follow-up within two years of carotid intervention; carotid bruit and follow-up for established carotid disease were the most prevalent uncertain indications; and inappropriate indications for carotid imaging were dizziness/vertigo, syncope (fainting) and blurred/change in vision, the authors report.

Guidelines recommend patients who receive revascularization have a five-year life expectancy. Among the 4,063 patients in the final sample, 3,373 (83 percent) received a CEA. Overall, 663 procedures were performed in patients 80 or older. Overall postintervention survival in the group was 71.4 percent at five years.

Rates of survival among patients who received carotid imaging based on appropriate indications was 66.4 percent; 72.1 percent for those who received imaging based on uncertain indications; and 68.8 percent for those who had imaging based on inappropriate indications, the study reports.

"Consideration should be given to improving the evidence base around carotid testing, especially around monitoring stenosis over long periods and evaluating carotid bruits. ... Finally, clarifying and harmonizing current guidelines and the development of evidence-based decision support tools to support appropriate patient selection for carotid imaging in practice can reduce the use of low-value imaging and improve long-term patient outcomes," the authors conclude.
-end-
(JAMA Intern Med. Published online April 18, 2016. doi:10.1001/jamainternmed.2016.0678. Available pre-embargo to the media at http://media.jamanetwork.com.)

Editor's Note: The article includes funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Media Advisory: To contact corresponding study author Salomeh Keyhani, M.D., M.P.H., call Scott Maier at 415-476-3595 or email scott.maier@ucsf.edu or call Judi Cheary at 415-750-2250 or email Judi.Cheary2@va.gov

The JAMA Network Journals

Related Imaging Articles:

Ultrasound imaging of the brain and liver
Ultrasound is commonly used in diagnostic imaging of the body's soft tissues, including muscles, joints, tendons and internal organs.
Major new issue of CVIA on imaging
Cardiovascular Innovations and Applications (CVIA) journal has just published a special issue on Noninvasive Cardiac Imaging with Guest Editor Dr.
Imaging at the speed of light
Over the past few years, Chunlei Guo and his research team at the University of Rochester have used lasers to manipulate the properties of target materials and make them, for instance, superhydrophilic or superhydrophobic.
Breakthrough in live coral imaging
Interdisciplinarity Scientists at University of Copenhagen (Denmark), University of Technology Sydney (Australia), and Oregon Health University (USA) have used a well-known biomedical imaging technique called optical coherence tomography (OCT) to obtain fascinating insights to the structural organization and dynamics of reef-building corals.
High-res biomolecule imaging
Tiny defects in diamonds known as nitrogen vacancy defects could lead to high-resolution images of the structure of biological molecules, according to a new study by MIT researchers.
New software automates brain imaging
When humans and animals learn and form memories, the physical structures of their brain cells change.
Live cell imaging using a smartphone
A recent study from Uppsala University shows how smartphones can be used to make movies of living cells, without the need for expensive equipment.
Many muons: Imaging the underground with help from the cosmos
Alain Bonneville, a geophysicist at Pacific Northwest National Laboratory, will present details on the muon detector for 'seeing' sequestered carbon dioxide and the comparative field tests at the American Geophysical Union Fall Meeting in San Francisco.
Imaging stroke risk in 4-D
A new MRI technique developed at Northwestern University detects blood flow velocity to identify who is most at risk for stroke, so they can be treated accordingly.
Enhancing molecular imaging with light
A new technology platform from Northwestern University is able to image molecules at the nanoscale with super-resolution.

Related Imaging Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...