AHJ: Carotid US + intima-media thickness is safer, cheaper than angio
A carotid ultrasound combined with measurement of intima-media thickness (IMT) is an effective and inexpensive screening tool for the detection of coronary artery disease (CAD), according to a study published in the June edition of the American Heart Journal.

“Angiography is the most accurate method of CAD diagnosis but is invasive, expensive and associated with some risk,” the authors wrote. "Additionally, noninvasive imaging for CAD often involves expensive equipment, radiation exposure and medication and/or contrast administration.”

Harmony R. Reynolds, MD, of the New York University Langone Medical Center in New York City, and colleagues evaluated the accuracy of carotid ultrasound to identify CAD and its relation to left ventricular systolic dysfunction (LVSD).

According to the authors, CAD is LVSD's most common cause and can often lead to the need for revascularization.

During the study, Reynolds and colleagues identified patients referred for angiography who had an ejection fraction of less than or equal to 40 percent of unknown origin to undergo carotid ultrasound. Cardiologists blinded to CAD status determined common carotid artery IMT and plaque. CAD was defined as patients who have a coronary stenosis of 50 percent or greater.

Additionally, the cardiologists identified ischemic LVSD as either left main and/or proximal left anterior descending coronary artery that was 75 percent or greater blocked or two or more major arteries with 75 percent or greater stenosis.

Overall, the researchers looked at 150 patients who had a mean ejection fraction of 27 percent. Results showed that 42.7 percent of patients had significant CAD, 26.7 percent had ischemic LVSD and plaque was present in 63.3 percent of patients.

Additionally, the researchers noted that mean IMT was greater than 0.9 mm in 46 percent of patients and no plaque had negative predictive value of 98 percent for ischemic LVSD.

"Our research has identified that carotid artery ultrasound is capable of identifying the presence of severe and extensive coronary artery disease," said Reynolds.

"Based on our findings, physicians might consider using the carotid ultrasound test as an initial screen for CAD in patients with reduced heart pump function and no history of heart attack. If a patient tests positive for plaque buildup in the neck arteries, then it can be followed by angiography of the heart arteries,” noted Reynolds.

The authors concluded that noninvasive carotid ultrasound with IMT could be a valuable screening tool for excluding an ischemic etiology of LVSD when CAD is a probable diagnosis in patients.