September 17, 1998
For more information, contact:
Julie Miller or
John Pontarelli, [email protected]
New Ultrasound Technique for Assessing Blood Flow in the Heart Developed by Rush Researchers
A new ultrasound technique known as contrast echocardiography has been found to safely and consistently diagnose blood flow abnormalities in the heart muscle, according to researchers at Rush-Presbyterian-St. Luke's Medical Center, Chicago.
"Now, using only one test and one hour, physicians can provide the same quality of diagnostic testing that previously required the use of several tests and numerous hours of the patient's time," according to Dr. Steven B. Feinstein, director of the Rush echocardiography laboratories and inventor of OPTISON, a new ultrasound contrast agent recently approved by the U.S. Food and Drug Administration.
Feinstein will announce his findings Thursday, Sept. 17 at the 13th Annual Echocardiography Symposium at the Regal Knickerbocker Hotel in Chicago. Symposium participants include cardiologists and researchers from the United States, Europe and Asia.
Since February, Feinstein and his colleagues have used OPTISON while performing echocardiograms to evaluate myocardial tissue perfusion in more than 250 patients at Rush.
"This new application for contrast echocardiography is clearly a breakthrough in allowing physicians to use ultrasound to safely and reliably evaluate how well blood is flowing in the heart muscle itself," says Feinstein. "Since blood carries oxygen to the heart muscle, inadequate blood flow in one or more regions may indicate risk of a heart attack."
Feinstein and colleagues also have shown the relative cost effectiveness of contrast echocardiographic imaging techniques, based in part on the number of times a patient is able to avoid more expensive or redundant tests. Traditionally, physicians use a combination of noninvasive tests to diagnose heart disease depending on the patient's condition and the physician's assessment.
Other tests, positron emission tomography (PET) and thallium scans can produce images of the heart similar to those produced by contrast echocardiography, but they use nuclear agents. Also, PET and thallium scans are more expensive than echocardiography and require the patients to be moved to the equipment, whereas echo equipment is portable.
Conventional echocardiography is the most frequently performed noninvasive cardiac imaging technique today. It uses reflected sound waves to create a picture of the heart structure on a monitor while the test is being performed. However, conventional echocardiography cannot produce an image of blood perfusion of the heart tissue. To show tissue perfusion, echo images must be enhanced by a contrast agent during a contrast echocardiography procedure.
Feinstein's contrast echocardiography scans use OPTISON, an ultrasound contrast agent that can be injected during the echocardiogram to reflect ultrasound waves as it travels with blood through the smallest blood vessels and tissue of the heart. The clinical safety of OPTISON has been widely demonstrated.
Earlier this year, Feinstein and his colleagues in the Rush Heart Institute discovered that by using OPTISON with the most advanced echocardiography machines available, they could see the contrast agent as it traveled with blood through capillaries, the smallest arteries in the heart. The contrast-enhanced picture showed physicians where blood flow was adequate and where it was restricted.
"We have been trying to use ultrasound to evaluate myocardial tissue perfusion in a reliable way since the early 1980's, and now it's possible," Feinstein said. "Using a commercially available machine and contrast agent, we can now provide a superior level of diagnostic screening in a clinical setting. Contrast agents are available in more than 800 hospitals in the U.S., so everyone can benefit from clearer, faster and more accurate diagnostic testing of coronary artery disease."
OPTISON is a second-generation contrast agent for echocardiography. Feinstein also invented its predecessor, ALBUNEX, the only other FDA-approved ultrasound contrast agent, which continues to be used to diagnose gynecological abnormalities. Ultrasound scans are used to look at form and function of several organs, including the brain, kidney, and liver, as well as the reproductive organs.
About 14 million conventional echocardiograms are performed each year in the United States, many of them are repeat tests because images of the heart are unclear. Contrast echocardiograms currently account for one percent of the total number of echocardiograms done, although their use is quickly growing due to greater accuracy and lack of adverse reactions in patients.
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Rush-Presbyterian-St. Luke's Medical Center includes the 590-bed Presbyterian-St. Luke's Hospital; 154-bed Johnston R. Bowman Health Center for the Elderly; Rush University (Rush Medical College, College of Nursing, College of Health Sciences, Graduate College); and seven Rush Institutes providing diagnosis, treatment and research into leading health problems. The medical center is the tertiary hub of the Rush System for Health, a comprehensive healthcare system capable of serving about two million people through its 9 member hospitals and outpatient facilities.
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