Description of Restrictively Defined Acute Flaccid Myelitis

Abstract

uncomplicated Kawasaki disease (KD) who had previously normal coronary artery dimensions by echocardiography at diagnosis and at 1 to 2 weeks of illness. Maccora et al express concern about the 1.7% of our analysis cohort who had z scores at 6 weeks of more than 2.0. Although dimensions in the patients were present at 4 to 6 weeks, the degree of coronary artery dilation was mild at best and did not persist. Of these 8 patients, most 1 had a follow-up z score of 2.0 to 2.4, which would not be considered enlarged according to the 2017 American Heart Association Kawasaki Disease Guidelines. 2 Of the remaining 3 patients, the coronary artery dimensions normalized in 2 children at late follow-up, and the third patient had minimal dilation (z score of 2.1); again, not considered clinically concerning based on the 2017 American Heart Association guidelines. Indeed, the 2017 KD guidelines designate early aspirin use (first 4-6 weeks of illness) in patients with mild coronary artery dilation (z score ≥2.0 and <2.5) as a class IIa recommendation with Level of Evidence C (ie, consensus of experts and standard of care, but no clinical trials) and allowed for their discharge from care after 1 year if their coronary arteries normalize. 2 To make a change in guidelines, the findings in our study would need to be validated in other populations and settings. With these data, the risk/benefit ratio of the 6-week echocardiogram and continued low-dose aspirin therapy in this subgroup of patients with KD would need to be reconsidered by a guideline committee of experts. Indeed, guidelines are periodically updated precisely because newly published data continue to define best medical practices. In addition to our published article, 1 data suggest that baseline echo findings are the most reliable predictors of significant coronary artery complications in KD 3 and that thrombotic complications on longterm follow-up are exceedingly rare in patients even with small aneurysms (M.B.F. Son, MD, et al; unpublished data; 2018). For now, we reiterate our very strong support for obtaining highquality echocardiographic imaging of the coronary arteries in the earliest weeks after KD diagnosis, when coronary artery dimensions may be progressively dilating and additional antiinflammatory therapies can potentially prevent progression to significant coronary complications.