Electron beam computed tomography (EBCT), also known by the brand name Ultrafast CT®, is an especially fast X-ray imaging technology used to measure the accumulation of calcium in coronary arteries, known as coronary calcification. In other patient populations, the amount of calcium has been linked to the amount of underlying coronary artery disease (CAD).
Kawasaki disease is a leading cause of acquired heart disease in U.S. children – meaning they were not born with the condition. More than 1,800 cases of Kawasaki disease are diagnosed annually in the United States, according to American Heart Association statistics. It usually occurs before age 5 and rarely after age 8. Symptoms include fever, rash, swollen hands and feet, swollen lymph glands in the neck, and inflammation of the mouth, lips and throat. In about 20 percent of Kawasaki cases, the heart is involved and the coronary arteries or the heart muscle itself can be damaged permanently. This disease can also lead to an aneurysm, in which an artery wall weakens and bulges out.
Many case reports have shown that some Kawasaki patients with aneurysms may develop coronary blockages years later, thereby increasing their risk of heart attack or sudden death. The long-term impact on the heart as children progress into adulthood has not been determined.
“We sought to further understand whether Kawasaki patients have sustained or progressive changes to their coronary arteries long-term – more than five years after initial diagnosis,” explains Gul H. Dadlani, M.D., now a fellow in pediatric cardiology at University of Rochester’s Strong Children’s Hospital in Rochester, N.Y., and lead investigator of the study.
He and colleagues at Children’s Hospital of Buffalo, in Buffalo, N.Y., enrolled 18 young people ages 5 to 22 who had experienced Kawasaki disease.
Participants underwent EBCT screening of their coronary arteries. To assess the participants’ risk, researchers used a coronary artery calcium scale that is used in adults to determine the future risk of developing CAD. A calcium score of 10 or less indicates low risk; a score from 11-100 indicates moderate risk; 101 – 399 shows moderately high risk and a score of 400 or more denotes high risk.
Some level of coronary artery calcium was found in four of the 18 patients (22 percent). The scores were 14, 159, 1013 and 6,441, so one patient had moderate risk, one had moderately high risk and two had a high risk for future coronary artery disease.
Each of the four with positive EBCT scans had a history of coronary artery aneurysm at the time of their acute Kawasaki disease. The coronary artery calcium deposits were located at the sites of previous aneurysm formation, the physicians note.
“Although the study includes a small number of patients, our conclusion is that EBCT can be an effective non-invasive method of screening former Kawasaki patients who have a history of aneurysms for the presence of coronary artery calcifications,” Dadlani says. Currently, former Kawasaki patients are examined periodically with ultrasound to assess whether they might have signs of coronary artery changes. The American Heart Association’s recommendations for long-term care of Kawasaki patients are based on the severity of coronary involvement. They advise that a cardiologist conduct annual follow-up tests with echocardiograms or perhaps with electrocardiograms (EKG) for patients who had aneurysms. An echocardiogram is an ultrasound image that shows the size, shape and movement of the heart. An EKG is a graphic record of electrical impulses produced by the heart.
Dadlani says adding EBCT could help predict disease, but further assessment of the technology is needed.
“We are seeing more and more studies that indicate EBCT can be used to evaluate post-Kawasaki disease in children. It is our hope that it will prove a promising tool for long-term evaluation of children with persistent aneurysms,” says Kathryn Taubert, Ph.D., vice president of science and medicine for the American Heart Association and a Kawasaki disease researcher.
The cause of Kawasaki disease and the reason it affects the hearts of some patients remains unknown.
“The current thinking is that there may be a genetic predisposition to an infectious agent, which may be a virus or bacteria, that results in all of the symptoms of Kawasaki disease,” says Dadlani.
Dadlani says he and his colleagues hope to organize a larger study to confirm their findings. Other co-authors are: Robert L. Gingell, M.D.; Joseph D. Orie, M.D.; Jean-Michel A. Roland, M.D.; Daniel McKenna, M.D.; Jan Najdzionek, M.D.; and Daniel R. Pieroni, M.D.
CONTACT:
For information Nov. 10 – 14 call:
Carole Bullock or Bridgette McNeill
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(714) 251-5801
Abstract 2439
NR01-1358 (Sessions/Dadlani)