Tissue Doppler Imaging as a Predictor of Immunoglobulin Resistance in Kawasaki Disease.

Abstract

Kawasaki disease (KD) is characterized by myocarditis and left ventricular dysfunction during the acute phase of the illness. Despite treatment with intravenous immunoglobulin (IVIG), a significant number of patients are IVIG resistant. We evaluated KD patients in the acute phase of illness using tissue Doppler imaging (TDI) to assess whether myocardial dysfunction may predict IVIG resistance. All patients with acute KD presenting to Children's Hospital Colorado from February 2007 through March 2014 were included in this study and underwent echocardiograms with TDI evaluation at diagnosis. Patients were divided into two groups: IVIG resistant and IVIG responder. Group differences were assessed using Wilcoxon-Mann-Whitney and Chi-square testing. Receiver operating characteristic (ROC) curve analysis was utilized to determine threshold values of TDI measurements associated with IVIG resistance. Fifty-one age-matched IVIG resistant patients were compared to 51 IVIG responder patients [median age, IQR 44.57 (20.13-77.07) vs. 33.49 (17.30-62.89) months, p<0.44]. There were significant differences in the septal and mitral early diastolic velocities (E') (p<0.001 and p<0.01), respectively. ROC analysis demonstrated that tricuspid E' <0.15cm/s, septal E' <0.12cm/s, and mitral E' <0.16cm/s were good predictors of IVIG unresponsiveness (AUC=0.66, 0.66, and 0.70, respectively). There were no differences between the systolic velocities and late diastolic velocities (A'). IVIG resistant KD patients present with significantly greater diastolic dysfunction compared to responders in patients with KD. TDI may be a useful tool to differentiate KD patients at higher risk of IVIG resistance.