Coronary artery wall thickness helps differentiate febrile children with and without Kawasaki disease

BACKGROUND: Transthoracic echocardiography is useful for evaluating coronary lumen but has limited sensitivity in distinguishing between febrile non-Kawasaki disease (FNKD) from Kawasaki disease (KD) children when significative coronary artery dilation is absent. This cross-sectional study assessed the accuracy of coronary artery wall thickness (CAT) as a novel echocardiographic parameter to differentiate FNKD from KD children. CAT was calculated as the difference between the coronary external diameter (CED) and lumen diameter; CED was measured as the distance between the outer edges of the lines representing the coronary artery wall.METHODS: CAT was evaluated in 67 FNKD hospitalized children (age 15 [7-36] months) and in 38 KD patients (age 19 [12-35] months), focusing on the proximal segment of left main coronary (LMCA) and right coronary artery (RCA). CAT were expressed as Z-score and the coronary artery thickness index (CATi) was calculated as the ratio of CAT/aortic annulus.RESULTS: FNKD patients had significantly lower CAT (P<0.0001), CAT Z-score (P<0.0001), and CATi (P<0.0001) than KD patients. ROC analysis identified LMCA CATi value ≤0.23 and an RCA CATi≤0.22 as optimal cut-off values for differentiating FNKD from KD patients with sensitivity of 100% and 97%, and a specificity of 94% and 98%, respectively.CONCLUSIONS: Echocardiographic CAT assessment effectively differentiates FNKD from KD children. LMCA CATi≤0.23 and RCA CATi≤0.22 demonstrated high sensitivity and specificity. If validated, this parameter could improve management in febrile pediatric children.