Transformation of coronary artery aneurysm to obstructive lesion and the role of collateral vessels in myocardial perfusion in patients with Kawasaki disease

Abstract

Objectives. The aim of this study was to examine the transformation of coronary artery aneurysms to obstructive lesions and to assess the role of collateral vessels in patients with Kawasaki disease.Background. Coronary artery aneurysms, especially giant aneurysms, are known to become obstructive lesions in patients with Kawasaki disease. However, the process of transformation is not yet clear.Methods. Thirty patients (average age 9.9 years) with obstructive lesions secondary to Kawasaki disease underwent repeated coronary artery angiography and thallium myocardial scintigraphy over a mean period of 7.7 years after the acute onset of Kawasaki disease.Results. In the 27 patients who were enrolled in the acute phase of the disease because of coronary artery aneurysms, the later transformation to obstructive lesions was not significantly different between the 61 large and 6 medium-sized aneurysms. Obstructive transformation of aneurysms was more rapid in the right than in the left coronary artery (p < 0.001). From the last coronary angiogram obtained, the obstructive lesions were classified as localized stenosis >90% in 10 vessels, occlusions in 6 vessels and segmental stenosis in 26 vessels. Both localized and segmental stenosis occurred significantly more often in the left anterior descending and the right coronary artery than in other vessels (p < 0.05). The incidence of collateral vessels was significantly correlated with a younger age at onset of Kawasaki disease, especially in patients with segmental stenosis (p < 0.001). Collateral vessels did not develop in the presence of localized stenosis regardless of the occurrence of myocardial ischemia. All occluded vessels had collateral development regardless of the presence of myocardial infarction.Conclusions. The treatment of localized stenosis may play an important role in preventing myocardial infarction in the chronic phase of Kawasaki disease.