Duration of High-Dose Aspirin Therapy does not Affect Long-Term Coronary Artery Outcomes in Kawasaki Disease

BACKGROUND: High-dose aspirin (HDA) is used with intravenous immunoglobulin (IVIg) in Kawasaki Disease (KD). Practice regarding HDA varies, and it is unclear whether HDA duration affects long-term course. METHODS: We retrospectively studied KD patients at our hospital over 10 years. Patients were categorized as having received HDA for 0, 1–7, or >7 days. Primary outcome was maximum coronary Z-score at diagnosis and follow-up; secondary outcomes included inflammatory markers. RESULTS: 103 patients had HDA duration documented; 35 had coronary artery abnormalities (CAAs) at diagnosis. There was no difference in demographics or inflammatory markers between HDA groups, and no difference in HDA duration between patients with or without CAAs. Seventeen patients received no HDA; they had longer illness and defervescence duration before diagnosis and were less likely to receive IVIg. For CAAs, multivariate regression revealed that HDA duration did not predict coronary Z-score at 9–15 months. Higher Z-score at diagnosis was associated with higher Z-score at 9–15 months. CONCLUSION: The only factor associated with coronary Z-score at 9–15 months was Z-score at diagnosis. At our institution, longer illness and defervescence duration and lack of IVIg administration were associated with not administering HDA. HDA duration did not affect clinically-relevant outcomes, particularly CAA persistence.