Follow-up duration of echocardiography in patients with Kawasaki disease with no initial coronary aneurysms.

OBJECTIVE To evaluate the optimal duration of echocardiographic follow-up in patients with Kawasaki disease without an initial coronary aneurysm. STUDY DESIGN In this single-center, retrospective, observational study, we reviewed the results of follow-up echocardiography in children with Kawasaki disease enrolled in the Prospective Observational study on Stratified treatment with Immunoglobulin plus Steroid Efficacy for Kawasaki disease from a children's hospital. The main enrollment criterion was the absence of coronary aneurysms, defined as a maximum Z score (Zmax) ≥2.5, in the proximal right coronary artery and the proximal left anterior descending artery within nine days from treatment initiation. The primary outcome was the Zmax on follow-up echocardiography of up to five years. RESULTS Among 386 patients, 106 (27.5%) received prednisolone with intravenous immunoglobulin for the first-line therapy, and 57 (14.8%) showed a poor response. Echocardiography at one month detected nine patients with Zmax ≥ 2, including three (0.8%) with coronary aneurysms requiring additional anti-thrombotic treatment and observation. Of seven patients (1.8%) with normal echocardiographic findings at one month but Zmax ≥ 2 later, two were lost to follow-up and five experienced spontaneous resolution, but none of the seven patients needed any change in their management. CONCLUSION The optimal duration of echocardiographic follow-up may be one month in patients with no initial coronary aneurysms and Zmax < 2 at one month. Coronary artery abnormalities observed after one month are rare and mostly benign in this category of patients.