Ultrasound May ID Heart Risk

Many middle-aged people who suffer heart attacks and strokes have few risk factors for heart disease or stroke. Now new research suggests that a simple ultrasound test could help doctors tell the difference between patients who really do have a low risk for cardiovascular events and those who just seem to.

Ultrasound imaging of the carotid neck artery proved remarkably effective for identifying seemingly low-risk patients who actually had cause for concern.

Nine out of 10 middle-aged study participants who had a cardiovascular event during the two-and-a-half year study showed early evidence of plaque buildup, or atherosclerosis, in the carotid arteries of the neck on the ultrasound.

Results from the study were presented Monday at the American Heart Association's 7th Scientific Forum on Quality of Care, held in Washington D.C.

Plaque Buildup

"The most significant finding was that only one of the people who had a negative scan had an event within the next few years," researcher Kwame O. Akosah, MD, tells WebMD.

Akosah, the director of the Heart Failure Clinic at Gunderson Lutheran Health Systems in La Crosse, Wis., says that the imaging procedure could prove to be an important addition to current screening measures.

Atherosclerosis occurs when fatty deposits and other substances, known as plaque, build up in the arteries. This buildup can raise risk for both heart attack and stroke.

Plaque buildup in a carotid neck artery is a signal that other important arteries may have the buildup as well; earlier studies suggested that ultrasound imaging of the neck artery could help predict cardiovascular risk.

Test Predicted Events

In the latest study, Akosah and colleagues at Gunderson and the University of Wisconsin performed the ultrasound imaging on 246 people. The average age of the males in the study was 55 and the average age of the females was 65.

All of the study subjects were considered to have a low overall risk for heart disease, meaning that they had relatively normal blood pressure and cholesterol, did not smoke, and had no other major cardiovascular risk factors, Akosah says. Those with a known history of coronary heart disease or who were taking medication for high cholesterol were not included in the study.

When the ultrasound was performed, 149 study participants showed evidence of carotid artery plaque buildup, while the rest did not.

The subjects were followed for about 32 months following ultrasound testing. During this follow-up, the people who had the abnormal tests were nearly three times more likely than those without plaque buildup in the neck artery to develop severe coronary artery blockage.

Of the 10 people in the study who either died or suffered from heart attacks or strokes, nine had evidence of noncardiac atherosclerosis on the earlier ultrasound.

And 27 of the 36 participants, including the previously mentioned 10 people and others who underwent cardiovascular procedures such as heart bypass surgery or angioplasty — or who were diagnosed with heart failure — also showed evidence of plaque buildup in their neck's carotid arteries on the earlier ultrasound.

More Work Ahead

Akosah says the findings need to be confirmed in larger studies.

American Heart Association spokesman David Goff, MD, PhD, agrees. Even if the findings are confirmed, he says, it is not clear if screening whole populations would result in more aggressive treatment — and better outcomes — for those found to be at risk.

"There are still many things that we simply don't know that keep us from recommending this as routine screening," he tells WebMD.

Goff and Akosah agree that taking steps to reduce heart disease risk are far more important than which tests people take to ascertain their risk. That means maintaining a healthy weight and eating a healthy diet, getting plenty of exercise, not smoking, and keeping blood pressure and cholesterol under control.

"If people follow these guidelines, screening can confirm that their efforts are working," Akosah says.

Sources: American Heart Association 7th Scientific Forum on Quality of Care, May 8, 2006; Washington, D.C. Kwame O. Akosah, MD, associate professor of medicine, University of Wisconsin, Madison; director, Heart Failure Clinic, Gunderson Lutheran Health System, La Crosse, Wis.. David Goff, MD, PhD, professor of health sciences and medicine, Wake Forest University, Winston Salem, N.C.

By Salynn Boyles
Reviewed by Louise Chang, MD
© 2006, WebMD Inc. All rights reserved