January 23, 1997

Media Contacts: Sarah Goodwin, Emory, 404/727-3366 or Kathi Ovnic, 727-5686
Larry Peters, Lifetech/Atlanta, 770/730-0019
Perry Witkin, Lifetech, 1/888/321-5700

The ability of Atlanta doctors to detect coronary artery disease more than a decade before symptoms appear will be greatly enhanced when Lifetech Cardiac Imaging Center opens in January. The center will be the first in Georgia to offer electron beam tomography -- a quick, painless, noninvasive and inexpensive means of imaging coronary arteries.

Lifetech America Inc. of Nashville, Tenn., received a certificate of need for the facility from Georgia's State Health Planning Agency. The center will be located at 1140 Hammond Dr., Building I, Suite 9120, Atlanta. Larry Peters is director of the center.

Randolph E. Patterson, M.D., director of Cardiovascular Imaging for the Emory Heart Center, is serving as medical director. In addition, the Emory University School of Medicine has contracted with the center to conduct cardiology research.

Cardiologists from Emory Heart Center, St. Joseph's Hospital, Piedmont Hospital, Northside Hospital and Georgia Baptist Hospital will guide the center.

After receiving special training, cardiologists from Emory and community practice will be performing and interpreting the images. Doctors will be looking for calcium, an early clue to the deadly process known as atherosclerosis that causes blockages in blood vessels. Emory and community radiologists will also be asked to review selected tests for possible noncardiac diseases, even though testing at the center will focus mainly on the cardiovascular system.

"Cardiologists, internists, gynecologists, family practice doctors and other primary care physicians from around the city may refer patients to the center for coronary calcium imaging," says Dr. Patterson, who also is professor of medicine and radiology at the Emory University School of Medicine. "A board-certified cardiologist will review the images and report test results to referring physicians."

Lifetech electron beam tomography requires no physical exertion like heart tests such as the exercise thallium stress test or electrocardiogram (ECG).

The technology is an improvement over other computed tomography (CT) scanners for cardiac imaging because it acquires images more quickly -- about 10-14 images per second, Dr. Patterson says. The fast scanner is required to "stop the motion" of the heart and its coronary arteries long enough to create an accurate picture.

The complete electron beam tomography test requires only five to 10 minutes of the patient's time, and involves no needles, exercise, drugs, X-ray dye (contrast agents) or undressing.

The special advantage of electron beam tomography over other noninvasive cardiac tests is that it detects the atherosclerotic disease process itself in the coronary arteries, Dr. Patterson says. Coronary atherosclerosis grows progressively over time, like a time bomb with a variable delay detonation time measured in years. Other noninvasive tests are not conducted until the disease progresses enough to narrow the openings in the artery by at least 50 percent -- a narrowing which limits the maximum flow of blood through the artery. When blood flow does not deliver enough blood to supply the needs of the heart muscle, the heart may develop abnormalities which can be detected by ECG or other methods.

"If we know who has the disease, we can offer very effective treatment," Dr. Patterson says. "The problem has been that we often don't know who has coronary atherosclerosis until the person has a heart attack, sudden death or develops symptoms. At these points, treatment options decrease or end. The electron beam tomography system provides an accurate test for coronary artery disease per se -- not just its consequences -- before symptoms appear.

"If a person has coronary athersclerosis, the American Heart Association recommends more intensive efforts to lower cholesterol levels and decrease other risk factors. For example, a physician would be more likely to recommend drug treatment to lower cholesterol if the patient were known to have heart disease. Also, patients who know they have the disease are more highly motivated to change their lifestyle through improving diet, exercising and quitting smoking."

Chicago resident and former heart patient Jim Dunfee, for instance, credits electron beam tomography with saving his life. Although he had no symptoms, the test nonetheless detected advanced coronary artery disease. Mr. Dunfee subsequently underwent six-vessel bypass surgery.

Heart disease is by far the leading killer of Americans -- and far more lethal than AIDS and all cancers combined. The American Heart Association estimates about 1.5 million Americans will experience a heart attack this year and about one third will not survive. That translates to a heart attack every 20 seconds with every third one being fatal. For example, coronary artery disease kills six times the number of women who die of breast cancer.

"We want to improve these harrowing statistics," says Perry A. Witkin, president of Lifetech. "Our goal is to revolutionize the early diagnosis and treatment of coronary disease."

For information, call 770/730-0019.

Electron Beam Tomography & Heart Disease

"Electron beam tomography (EBT) is an innovative outgrowth of computed tomography (CT) technology specifically developed to image fast enough to freeze the beating heart," according to literature developed for health professionals by Lifetech Inc., the Nashville, Tenn.-based company introducing EBT to Georgia. "Instead of a mechanically rotating X-ray tube, an electromagnetically-steered and precisely focused beam of electrons is scanned around a tungsten target... which permits imaging of the native vessels in a single breath-hold without any injection of contrast. (It)... has the unique ability to detect and quantify minute amounts of calcified plaque in the major coronary arteries."

EBT images of calcium in the arteries can detect coronary artery disease (CAD) that narrows the diameter of arteries by at least 50 percent in more than 95 percent of patients over 40 years old with symptoms of chest discomfort, says Randolph E. Patterson, M.D., director of Cardiovascular Imaging for the Emory Heart Center.

He will serve as medical director for the Lifetech Cardiac Imaging Center opening in January in Atlanta. Below, he elaborates on EBT and heart disease diagnosis.

Unlike most other tests, EBT can detect CAD with equal accuracy in women and men.

About half of patients with symptoms yet no "significant" CAD (that narrows one or more coronary arteries by 50 percent or more) show some calcium on EBT. Recent studies have produced an exciting new understanding of the detection of calcified plaque deposits in coronary arteries. Research from the Mayo Clinic has shown unequivocally that detection of calcium by EBT proves the artery has some atherosclerotic plaque, even if it is not yet obstructing blood flow. In previous years, the patient with or without symptoms who had no arterial narrowing over 50 percent was told not to worry because symptoms were not due to insufficient coronary blood flow. In fact, many physicians did not wish to detect this mild CAD because they did not believe they had effective therapy to offer patients with less than 50 percent narrowing.

In recent years, three facts important in preventing complications of CAD have been established, namely the following:

  1. Acute heart attacks can occur in patients whose arteries are less than 50 percent blocked. In some of these patients, plaque rupture can indeed occlude an artery -- even if cardiac tests called arteriograms taken one or two years prior showed less than 50 percent obstruction.

  2. People with completely normal coronary arteriograms have a better five-10 year outlook than people with mild arterial narrowing (less than 50 percent).

  3. Most importantly, programs that reduce cholesterol and other risk factors for CAD also reduce the incidence of cardiac death, acute heart attack, angina pectoris, coronary artery bypass graft surgery and coronary angioplasty. In the past two years, studies have proven that the benefits of risk factor reduction apply not only to patients with known CAD but also to people with no evidence of CAD at study initiation.

Thus, the evolution in basic scientific understanding of the biology of atherosclerotic plaque has led to effective treatments. The only reservation about widespread application of treatments such as drugs to lower cholesterol is the cost of these programs for people without proven CAD.

EBT is capable of reducing health care costs if it can identify those people without symptoms who are at high risk for clinical complications of CAD. A recent study showed that EBT did predict cardiac events in a group of 1,173 people without symptoms even when the follow-up period was short-term, only 19 months. The risk of a coronary event was 26-fold greater in people with positive (5.5 percent) versus negative (0.2 percent) test results. EBT was substantially more powerful in predicting risk than the Risk Factor Profile used by the National Cholesterol Education Program.

Other studies have shown similar results, so it appears that EBT is the most useful test to identify those people without symptoms who are nonetheless at risk for CAD events. A positive exercise electrocardiogram (ECG), for example, only identifies people without symptoms with a four- to eight-fold increase in risk of coronary events over several years.

The ability to identify high-risk people who have no symptoms of heart disease has the following major benefits for preventing coronary events due to CAD:

  1. The most intensive prevention measures may be focused on those people at highest risk;

  2. The intensity (and expense) of prevention measures focused on people at low risk may be reduced;

  3. Seeing an EBT picture of calcium beginning to occlude one's own arteries serves as a powerful incentive for patients to make positive, risk-reducing lifestyle changes;

  4. Such targeted prevention programs have the potential to help decrease complications and costs of CAD -- and thereby help reduce the overall cost of health care.

For more general information on The Robert W. Woodruff Health Sciences Center, call Health Sciences News and Information at 404-727-5686, or send e-mail to

Copyright ©Emory University, 1997. All Rights Reserved.
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