SAN DIEGO — Cardiac abnormalities in patients with Kawasaki disease may appear well after their short-term treatment phase, even in those with no previous evidence of cardiac involvement, results from a follow-up study show.
The results “further support a need for long-term follow-up of all patients with Kawasaki disease,” Rosie Scuccimarri, M.D., reported at an international Kawasaki disease symposium. “Patients who have had normal echoes at 8 weeks should also have echocardiograms at least every 5 years.”
For the study, she and her associates contacted 221 patients who had been admitted to Montreal Children's Hospital with a diagnosis of Kawasaki disease during January 1985 to December 1999 and who were treated in the acute phase of their disease with intravenous immunoglobulin and low-dose aspirin. The aim was to conduct late follow-up echocardiographic evaluations, and of the 221 patients contacted, 159 participated in the study.
Patients identified as having echocardiographic abnormalities within 8 weeks of Kawasaki disease diagnosis or during later follow-up visits (38) were matched to those in which no prior abnormalities were detected (121). The mean age of disease diagnosis was 3 years, and the mean age at study visit was 11 years.
Of the 38 patients in whom abnormalities had been detected previously, 12 had coronary artery lesions, which translated into an incidence of 7.5% in the entire study group.
A coronary vessel was defined as abnormal if its diameter was greater than 3 mm in a child younger than 3 years, greater than 3.5 mm in a child aged 3-5 years, greater than 4 mm in a child aged 5-11 years, and greater than 5 mm in a child older than 11 years.
All 38 patients with abnormalities had complete resolution of their original abnormalities, but 8 (21%) had developed new pathology on long-term follow-up.
The investigators also observed that 7 of the 121 patients (6%) with normal echocardiograms on early follow-up had abnormal results on late follow-up, including one with a new coronary artery lesion.
“There was a significant interest by patients to participate [in the study],” noted Dr. Scuccimarri, a pediatric rheumatologist at McGill University Health Center, Montreal. “We were lucky enough to have patients who came [from] as far as Hong Kong, Western Canada, and the United States at their own expense.”
In another part of the study, a subgroup of 35 patients underwent a stress test using technetium-99m sestamibi (stress MIBI) with continuous ECG monitoring: 18 who had echocardiographic abnormalities at early or late follow-up and 17 who had no such abnormalities.
Among the 18 patients with abnormalities at early or late follow-up, 1 had an abnormal stress ECG, she said at the meeting, which was sponsored by the American Heart Association. Among those without evidence of abnormalities, one had an abnormal ECG, and one had an abnormal stress MIBI. She concluded that stress-MIBI testing and long-term follow-up “needs to be evaluated further.”