Imaging
Ryuji Fukazawa, n/a
Associate Professor
Nippon Medical School
Tokyo, Tokyo, Japan
Background: Although occlusion of the right coronary artery (RCA) is common in the remote stages of Kawasaki disease, revascularization of the RCA is challenging in children and is usually observed without intervention.
Methods: Using adenosine-stress 13N-ammonia myocardial perfusion positron emission tomography, we evaluated the coronary circulation in 14 patients (12 male) with RCA occlusion to identify the presence or absence of ischemia (myocardial flow ratio < 2.0) in the RCA region and examined indices of hemodynamics, cardiac function, and coronary aneurysm diameter. These issues also were compared in patients with/without RCA segmental stenosis (SS).
Results: There were five cases of ischemia in the RCA region. There was a trend toward increased RCA myocardial blood flow (MBF) at rest in patients with ischemia compared to those without (1.27 ± 0.21 vs. 0.82 ± 0.16 mL/min/g, p = 0.2053). A similar trend was observed for MBF in the left anterior descending artery (LAD) region (1.37±0.66 vs. 0.90±0.25 ml/min/g, p=0.2053). Adenosine stress reduced vascular resistance in the LAD region and increased blood flow, while the response of vascular resistance in the RCA region was significantly reduced. Nine patients presented with RCA SS, and the age at onset of Kawasaki disease tended to be lower in SS （22.1±17.5 vs. 41.4±25.4. p=0.1239）. The maximum aneurysm diameter of RCA was significantly smaller in SS (10.0 ± 2.8 vs. 14.7 ± 1.6, p = 0.0239). No significant differences in other indices were observed between the patients with/without ischemia and SS.
Conclusions: At rest, the MBF in the RCA region was relatively preserved, even in patients with RCA occlusion, and there was no progressive deterioration in cardiac function. Adenosine stress can reveal the manifestation of microcirculatory disturbances in only half of the patients, indicating that these issues are reversible in young patients with Kawasaki disease.