Supplementary file 1_Decoding clinical heterogeneity and age-related coronary risk in incomplete Kawasaki disease: a multicenter cluster analysis and structural equation modeling study.docx

C1 showed greater systemic inflammation, C2 was characterized by younger age, longer pretreatment fever duration, and marked thrombocytosis, C3 by prominent hepatobiliary involvement, and C4 by a relatively low-inflammatory profile. C2 had the highest CAA prevalence (68.9%) and greatest coronary burden, whereas C3 had the highest IVIG-resistance rate (12.7%). Younger age, longer pretreatment fever duration, fewer clinical manifestations, lower albumin, lower hemoglobin Z-score, and lower neutrophil ratio remained independently associated with CAA.

SEM showed a strong direct association of age with CAA and only a small indirect association through symptom count and pretreatment fever duration. In the whole-KD analysis, iKD was unevenly distributed across the independently derived clusters. The major cluster characteristics and the greater post-IVIG coronary burden of C2 remained evident after exclusion of patients whose iKD classification depended on coronary findings.</p>Conclusions<p>iKD comprises clinically heterogeneous pretreatment phenotypes associated with different coronary and treatment-response profiles.

The coronary vulnerability of younger patients appears multifactorial rather than explained solely by longer pretreatment fever duration.</p>