Progression of Coronary Artery Abnormalities Following Timely Intravenous Immunoglobulin Administration in Children With Incomplete Kawasaki Disease: A Retrospective Cohort Study

IntroductionIncomplete Kawasaki disease (iKD) may be associated with coronary artery involvement despite treatment with intravenous immunoglobulin (IVIG).This study evaluated the occurrence and progression of coronary artery abnormalities following IVIG administration in children with iKD. Materials and methodsThis retrospective cohort study included children aged <18 years with iKD who received an initial IVIG dose of 2 g/kg within 10 days of fever onset and underwent baseline and follow-up echocardiography.Demographic, clinical, laboratory, treatment, and echocardiographic variables were also evaluated.The coronary artery dimensions were assessed using body-surface-area-adjusted z-scores.Coronary artery abnormality was defined as a maximum coronary artery z-score ≥2.5, and progression was defined as an increase of ≥1.0 in the maximum coronary z-score between baseline and the highest follow-up assessment. ResultsA total of 396 children were included, with a mean age of 24.1 ± 18.7 months; 228 (57.6%) were male.IVIG was administered within seven days of fever onset in 279 (70.5%) children and between days eight and 10 in 117 (29.5%).IVIG resistance was observed in 45 (11.4%) children.At baseline, 36 (9.1%) children had coronary artery abnormalities (maximum z-score ≥2.5), while 72 (18.2%) had coronary artery dilation (maximum z-score 2.0-<2.5).The 36 children with baseline coronary artery abnormalities were excluded from the analysis of newly developed abnormalities, leaving 360 children without baseline coronary artery abnormalities.Among these 360 children, 24 (6.7%) developed new coronary artery abnormalities during follow-up.These children were younger, were more frequently aged <12 months, had longer fever duration, received IVIG later, had more frequent IVIG resistance, had higher C-reactive protein (CRP), leukocyte, and platelet counts, had lower albumin concentrations, and had higher baseline maximum coronary artery zscores.Coronary progression occurred in 42 (10.6%) of the 396 children.The mean maximum coronary artery z-score increased from 1.09 ± 0.72 at baseline to 1.32 ± 0.96 at the highest follow-up assessment (mean difference, 0.23; 95% CI, 0.08-0.38;p = 0.003).The proportion of children with coronary artery abnormalities increased from 36 (9.1%) at baseline to 51 (12.9%) during follow-up (p = 0.015). ConclusionCoronary artery abnormalities may develop or progress after IVIG treatment in children with iKD.Younger age, delayed IVIG administration, IVIG resistance, greater systemic inflammation, and higher baseline coronary z-scores are associated with adverse coronary outcomes.Therefore, serial echocardiographic surveillance may be important following IVIG treatment, particularly in children with these risk characteristics.