Abstract 55: Histological And Rheological Evaluation At Coronary Artery Lesions In Patients With Kawasaki Disease Within 2 Years From Onset

Abstract

Background: Some paper reported that intravascular ultrasound (IVUS)- virtual histology (VH) showed atherogenesis in the evolution of coronary artery lesions (CAL) in young adults long after Kawasaki disease(KD). However, there is no report about those findings during early phase of KD. Purpose: We perform coronary intimal histologic evaluation by IVUS-VH for KD patients with CAL within two years from onset. Furthermore, we calculate shear stress in the target site and examine whether rheological potential affects to vascular histological change after KD. Subjects and Methods: IVUS-VH was performed in 12 Japanese KD patients (median age, 5.1 years) during 2 years after onset of KD (median, 10.2months) . All these patients had giant aneurysm in another branches. We investigated 20 coronary branches including 10 sites of small aneurysm (s-AN), 10 sites of regressed s-AN, and 20 sites of normal segment. Each of the 4 plaque components was assigned a respective color and defined as follows: fibrous area (green); fibro-fatty area (yellow) ; necrotic core area (red); and dense calcium area (white). Moreover, we measured average coronary peak flow velocity by Flow wire and calculated shear stress in the each sites. Results: 10 sites of s-AN showed prominent endothelial hypertrophy with fibrous and/or fibro-fatty plaques. In 7 sites of these 10 sites, dense calcium and necrotic core localized which indicates early phase of atherosclerosis. 10 sites of regressed s-AN had circumferential endothelial hypertrophy occupying mainly fibrous and/or fibro-fatty plaques composition. In 8 sites of these regressed 10 sites, dense calcium and necrotic core locally existed. On the other hand, normal segment in 20 sites had no plaque in 19 sites and trivial plaque in 1 site. Moreover, shear stress in all evaluated VH sites were within normal limit, which shows rheological potential doesn’t affect to vascular remodeling in such coronary artery lesions. Conclusions: IVUS-VH study revealed that initial atherosclerotic findings locally existed not only at small aneurysm site but also at regressed site. Therefore, careful further investigation to vascular remodeling in KD patients with CAL including regressed s-AN will be need.