Clinical History A 26 year-old woman with a history of Kawasaki disease (KD) that was diagnosed and treated when she was a year-old, presented with symptoms of exertional left-sided chest tightness with occasionally associated left-arm discomfort. Her symptom-complex was more apparent after she ran out of her prescription of clopidogrel. She has known coronary artery aneurysms, and a cardiac CT angiogram (CTA) was ordered to rule-out intravascular thrombosis.
CTA demonstrated a moderate calcified coronary artery aneurysm in the proximal left anterior descending artery (LAD) and a moderate aneurysm in the proximal right coronary artery (RCA). No thrombus was evident within the aneurysms, and an incidental moderate narrowing of the proximal RCA was noted. The patient subsequently underwent a stress-perfusion imaging evaluation, which did not reveal evidence of reversible ischemia.
Figure 1. Maximum-intensity projection (MIP) demonstrating a 1 x 0.9 cm calcified aneurysm in the proximal LAD.
Figure 2. MIP demonstrating proximal RCA (1 x 1 cm) and calcified proximal LAD aneurysms.
Discussion KD is a vasculitis of infancy and early childhood. It is an immune-mediated vasculitis with an unknown etiology, and a self-limited clinical course. 20-25% of children develop coronary artery aneurysms if treated with aspirin alone, and the incidence is reduced to 4-5% in patients treated with intravenous immune globulin (IVIG). Large aneurysms may predispose to intravascular thrombosis (RCA > LAD), and myocardial infarction. Patients with documented intravascular thrombosis are usually treated with a combination of low-dose warfarin (INR between 2-2.5) and low-dose aspirin.
Multidetector CT is an excellent noninvasive tool, in the long-term follow-up of symptomatic patients with giant coronary aneurysms. Due to our patient's young age and the possibility of serial follow up examinations, the study was obtained using a prospective triggering protocol, exposing her to a total of only 1.6 mSV of radiation.
Kawasaki, T. et al. A new infantile acute febrile mucocutaneous lymph node syndrome (MLNS) prevailing in Japan Pediatrics 1974; 54:271.
Kato, H et al. Long-term Consequences of Kawasaki Disease . A 10- to 21-Year Follow-up Study of 594 Patients. Circulation. 1996;94:1379-1385.
Newburger, JW. Et al. Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association. Circulation 2004; 110:2747.
Khositseth, A. et al. Giant coronary aneurysm caused by Kawasaki disease: follow-up with echocardiography and multidector CT angiography Brit. J. Radiol. 2008, e106-109.
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Suhny Abbara, MD MGH Department of Radiology
Wilfred Mamuya, MD, PhD MGH Division of Cardiology