It was found that when NT-ProBNP was used to assess cardiac injury in Kawasaki disease, the positive likelihood ratio and diagnostic odds ratio in the group over 3 years old were higher than those in the group under 3 years old (6.4 [4.5, 9.1] vs. 3.6 [3.0, 4.3]) (15 [10,24] vs. 32 [12, 81]), indicating that its diagnostic value and diagnostic efficacy were greater for the group over 3 years old. This evidence concerns the gene NPPB and Kawasaki disease.