Introduction: Aortic root dilation is a known finding in the acute/subacute phase of Kawasaki disease (KD). These changes may be inflammatory and related to the degree of coronary artery (CA) dilation, and may lag when compared to CA changes. Long-term changes in the aorta have not been previously reported.
Methods: A retrospective review of patients with KD from our institution was conducted, identifying individuals with American Heart Association (AHA) Risk Level 3, 4 or 5 over a 20 year period (1994-2014). Aortic annular and root dimensions were measured at the most recent echocardiogram and converted to z-score measurements. When possible, ascending aorta dimensions were measured, and all studies were evaluated for the presence of aortic regurgitation. Time from KD diagnosis to the last echocardiogram was determined. Patients with disease processes predisposing to aortic dilation were excluded, as were those with duration of echocardiographic follow-up <1 year.
Results: Fifty-three patients were identified, with a median age at diagnosis of 29 months (SD 42, 1.2-162 months). Twenty-seven (51%) were AHA Risk Level 3, 20 (38%) Risk Level 4 and 6 (11%) Risk Level 5. The mean time from diagnosis to latest echocardiogram was 7.3 years (1.4-17.3 years). Aortic annular and root dimensions were obtained in all patients (mean aortic annular z-score -0.06, mean aortic root z-score 0.67). Four patients (8%) had a dilated (z-score >2) aortic root, one also had a dilated annulus. Ten patients (19%) had borderline root dilation (z-score >1.5). Ascending aorta dimension measurements were possible in 72% (38/53) of the cohort, of which only 1 (3%) had a z-score >2 and 3 (8%) had a z-score >1.5. Importantly, no patients demonstrated aortic regurgitation.
Conclusion: In patients with history of KD and significant coronary artery involvement, borderline/mild dilation of the aortic root is not uncommon at intermediate to long- term follow-up, suggesting the possibility of a higher degree of aortic involvement in the acute and subacute phase of the disease process. The ascending aorta appears to be less affected and there was no evidence of functional derangements of the aortic valve. Accurate measurement of the aortic root dimension at all stages of KD is warranted.