CT measures potentially dangerous arterial plaque in diabetic patients

April 22, 2014, Radiological Society of North America

Imaging of the coronary arteries with computed tomography (CT) angiography provides an accurate assessment of arterial plaque and could have a dramatic impact on the management of diabetic patients who face a high risk of heart attacks and other cardiovascular events, according to a new multicenter study published online in the journal Radiology.

Plaque that forms in the arterial walls can restrict blood flow and, in some cases, rupture, leading to potentially fatal heart attacks. There is considerable evidence that calcified, or stable, , is less prone to rupture than non-calcified, or soft, plaque. Intravascular ultrasound can quantify non-calcified and calcified coronary artery plaque, but it is invasive and unsuitable for screening purposes, and coronary artery calcium (CAC) scoring with CT, a common noninvasive option, has limitations.

"Calcium scoring measures how much calcified plaque a person has, but it doesn't measure the component that's not calcified, and that's the component that tends to be dangerous," said João A. C. Lima, M.D., from the cardiology division at Johns Hopkins University in Baltimore, Md.

Quantitative plaque analysis with coronary computed tomography angiography (CCTA) has emerged as a viable screening option. CCTA can capture the full anatomic map of the coronary arteries in a single heartbeat with low radiation dose. CCTA can provide a picture of the total amount of plaque throughout the arteries of the heart.

Researchers from three centers—the National Institutes of Health (NIH) in Bethesda, Md., Johns Hopkins, and the Intermountain Medical Center Heart Institute in Salt Lake City—recently collaborated to evaluate CCTA in 224 asymptomatic diabetic patients. Obese people with diabetes have a propensity for extensive and premature development of coronary artery plaque, making them an ideal study group for plaque assessment.

The researchers used measurements of coronary artery wall volume and length to determine a coronary plaque volume index (PVI) for each patient. The technique provided information well beyond the presence or absence of coronary stenosis, or narrowing. PVI was related to age, male gender, body mass index (BMI) and duration of diabetes. Younger individuals with a shorter duration of diabetes had a greater percentage of soft plaque.

"Coronary plaque volume index by CCTA is not only clinically feasible and reproducible in patients with diabetes," said David A. Bluemke, M.D., Ph.D., from the NIH Clinical Center. "It provides a more complete picture of the coronary arteries that could be routinely applied in at-risk patients."

"These findings represent a very important step in the ability to quantify plaque, particularly non-calcified plaque," added Dr. Lima.

BMI, a measure of body fat based on weight and height, was the primary modifiable risk factor associated with total and soft coronary plaque as assessed by CCTA.

"The results reinforce how important it is to evaluate BMI as a potential driver of overall diabetes," Dr. Bluemke said. "As the only modifiable risk factor, obesity is an important target for managing diabetic patients."

Only about one-third of the coronary plaque in patients showed calcification, underscoring the widespread presence of non-calcified plaque. The ability to distinguish between calcified and non-calcified plaque is important because treatment may vary based on plaque composition.

"People with soft plaque respond better to interventions, particularly medical therapy like statins," Dr. Lima said.

The researchers will continue monitoring the patients from the study to better understand the value of plaque assessment in predicting future cardiovascular events and to further define the role of plaque volume index versus CAC score. A clinical trial would be necessary to determine if risk factor reduction would result in reduced PVI.

"Now that we have baseline indices of plaque in the study patients, we can look for people who, despite optimal management, experience a cardiovascular disease event like a heart attack," Dr. Bluemke noted.

CCTA is likely to be valuable for other groups of patients at high risk for cardiovascular events, the researchers said, and may one day enable physicians to predict plaque development and treat it aggressively before PVI increases significantly.

Explore further: CT angiography improves detection of heart disease in African-Americans

More information: "Coronary Artery Plaque Volume and Obesity in Patients with Diabetes: The Factor-64 Study" Radiology, 2014.

Related Stories

CT angiography improves detection of heart disease in African-Americans

June 28, 2011
Researchers may have discovered one reason that African Americans are at increased risk for heart attacks and other cardiovascular events.

Calcium score predicts future heart disease among adults with little or no risk factors

April 15, 2014
With growing evidence that a measurement of the buildup of calcium in coronary arteries can predict heart disease risk, Los Angeles Biomedical Research Institute (LA BioMed) researchers found that the process of "calcium ...

Study shows link between HIV infection and coronary artery disease

March 31, 2014
Men with long-term HIV infections are at higher risk than uninfected men of developing plaque in their coronary arteries, regardless of their other risk factors for coronary artery disease, according to results of a study ...

International study finds heart disease similar in men and women

December 3, 2013
An analysis of data from an international multicenter study of coronary computed tomography angiography (CCTA) reveals that men and women with mild coronary artery disease and similar cardiovascular risk profiles share similar ...

Carotid Artery MRI helps predict likelihood of strokes and heart attacks

March 4, 2014
Noninvasive imaging of carotid artery plaque with MRI can accurately predict future cardiovascular events like strokes and heart attacks in people without a history of cardiovascular disease, according to a new study published ...

Recommended for you

A nanoparticle inhalant for treating heart disease

January 18, 2018
A team of researchers from Italy and Germany has developed a nanoparticle inhalant for treating people suffering from heart disease. In their paper published in the journal Science Translational Medicine, the group describes ...

Starting periods before age of 12 linked to heightened risk of heart disease and stroke

January 15, 2018
Starting periods early—before the age of 12—is linked to a heightened risk of heart disease and stroke in later life, suggests an analysis of data from the UK Biobank study, published online in the journal Heart.

'Decorated' stem cells could offer targeted heart repair

January 10, 2018
Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury - and getting them to stay there - remains challenging. In a new pilot study using an animal ...

Two simple tests could help to pinpoint cause of stroke

January 10, 2018
Detecting the cause of the deadliest form of stroke could be improved by a simple blood test added alongside a routine brain scan, research suggests.

Exercise is good for the heart, high blood pressure is bad—researchers find out why

January 10, 2018
When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular ...

Heart-muscle patches made with human cells improve heart attack recovery

January 10, 2018
Large, human cardiac-muscle patches created in the lab have been tested, for the first time, on large animals in a heart attack model. This clinically relevant approach showed that the patches significantly improved recovery ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.