22 - CORONARY ARTERY OUTCOMES AND RETREATMENT RATES IN CHILDREN WITH KD TREATED INITIALLY WITH HIGH-DOSE VERSUS LOW-DOSE ASPIRIN THERAPY

Background:   Several retrospective studies suggest similar outcomes in KD patients treated initially with low-dose aspirin compared with traditional high-dose aspirin. In 2017, our single KD center changed routine initial therapy for acute KD from high-dose to low-dose aspirin with IVIG.

Methods: We performed a retrospective cohort study at Ann & Robert H. Lurie Children’s Hospital of Chicago comparing coronary artery outcomes and retreatment rates in children with acute KD treated initially with high-dose aspirin (80-100 mg/kg/d) with IVIG  from 2010 to 2017 to those treated with low-dose aspirin (3-5 mg/kg/d) with IVIG from 2017 to 2023. Corticosteroid pulse therapy was administered to many high risk/nonresponder patients from 2010 to 2017 and RAISE protocol corticosteroid therapy was administered to high risk/nonresponder patients from 2017 to 2023.

Results: 460 patients were eligible for the study, 271 in the high-dose and 189 in the low-dose aspirin groups. The demographic and clinical features of the two groups were comparable, including baseline CA z-scores. The mean age in the low-dose aspirin group was lower than in the high-dose aspirin group, but the % of infants was comparable in the two groups. The rate of IVIG retreatment was 24.0% (65 of 271 patients) in the high-dose and 19.6% (37 of 189 patients) in the low-dose aspirin groups (p-value = 0.2). Among patients who did not receive steroid therapy as part of their acute KD treatment, the IVIG retreatment rate was 19.2% (41 of 213 patients) in the high-dose and 16.0% (15 of 94 patients) in the low-dose aspirin groups (p-value = 0.5). No significant differences were observed in maximal CA z-scores of the left anterior descending CA or right CA in the high-dose and low-dose aspirin groups.

Conclusion: Our study adds to the growing literature supporting the use of low-dose aspirin for the initial treatment of children with acute KD. This approach offers anti-platelet activity to prevent thrombosis in acute KD patients until CA outcomes are known, without potential side effects of high-dose aspirin. Reconsideration of AHA recommendations for high-dose aspirin administration for children with acute KD appears warranted.