Kawasaki aneurysms: a lingering threat.
Kawasaki disease causes fever, sore throat, and inflammation of various tissues. Scientists don't know what triggers this generally rare childhood illness, which disproportionately strikes youngsters of Asian ancestry. The acute symptoms usually subside after two or three weeks, but cardiac complications can linger.
Last week, at the American Heart Association's 64th scientific sessions in Anaheim, Calif., cardiologist Teiji Akagi of the Hospital for Sick Children in Toronto presented data on 537 youngsters with Kawasaki disease, the largest series of North American Kawasaki patients ever reviewed.
Seventy of these children had developed coronary artery aneurysms, which were identified by a variety of imaging methods. In reviewing the patients' medical records, Akagi and his colleagues discovered nine small aneurysms, 40 moderate ones and 21 larger ones, measuring about one-third of an inch wide.
For most of these children, the coronary aneurysm eventually vanished. Tw years after diagnosis, all nine of the small aneurysms had disappeared; five years after diagnosis, 80 percent of the moderate aneurysms had regressed. But the five-year picture for the large aneurysms remained disappointing: All 21 persisted, and nine children with this condition suffered a heart attack. Five of the nine had a heart attack within one year of their Kawasaki diagnosis, Akagi says.
The turbulent blood flow in a large aneurysms may lead to a blood clot, which can block the coronary artery, causing a heart attack, he explains.
Some of the children received anti-inflammatory medication during the early stage of the illness. Akagi's group found that aneurysms were most likely to subside in children treated with gamma globulin, a protein produced by the body to fight inflammation. Two years after diagnosis, 80 percent of the 16 gamma globulin patients showed no sign of aneurysm. Five years after diagnosis, only half of the 46 kids treated with aspirin, another anti-inflammatory drug, showed aneurysm regression.
The cardiac risk faced by children with large aneurysms suggests a need for more aggressive treatment, he adds. These youngsters may benefit from bypass surgery, in which surgeons replace the weakened coronary artery with a healthy vessel, Akagi says.
Even patients who show no sign of persistent aneurysm must be monitored closely for coronary artery damage, warns Hirohisa Kato, who studies Kawasaki disease at Kurume (Japan) University. When the aneurysm heals, the body adds scar tissue to the artery wall -- a process some researchers fear may heighten the risk of heart attack, Kato says.
|Printer friendly Cite/link Email Feedback|
|Author:||Fackelmann, Kathy A.|
|Date:||Nov 23, 1991|
|Previous Article:||Galileo snaps first close-up of an asteroid.|
|Next Article:||Illuminating tiniest microlaser on a chip.|