Bradycardia Associated with Prednisolone in Children with Severe Kawasaki Disease.

OBJECTIVE: To identify the prevalence of bradycardia associated with use of prednisolone in patients with Kawasaki disease and analyze the association between bradycardia and responsiveness to intravenous immunoglobulin (IVIG).

STUDY DESIGN: We performed a retrospective cohort study of 176 patients with severe Kawasaki disease admitted to the Tokyo Metropolitan Children's Medical Center between March 2010 and December 2015. The group treated with IVIG plus prednisolone therapy from February 2012 was compared with the control group who received IVIG monotherapy before this date. The primary outcome was the prevalence of bradycardia, defined as heart rate less than the first percentile for normal children. Next, we determined whether bradycardia was associated with the clinical course in the patient subgroup treated with IVIG plus prednisolone therapy.

RESULTS: The prevalence of bradycardia was significantly higher in the IVIG plus prednisolone subgroup than in the IVIG group (79.1% vs 7.1%; P?<?.001). The median time to bradycardia onset was 63.0 hours (2.6 days). Prednisolone decreased the heart rate by 15.1 beats/minute (95% CI 10.2-20.0; P?<?.001) on average from day 2 to 7 after the initial therapy. Logistic regression analysis revealed that bradycardia was associated with responsiveness to initial IVIG plus prednisolone therapy (OR 7.2; 95% CI 2.3-23.0; P?<?.001).

CONCLUSION: Bradycardia frequently occurred during IVIG plus prednisolone therapy in patients with Kawasaki disease, and was associated with responsiveness to IVIG.