Serial Echocardiograms Reveal Occult Coronary Dilation in Patients with Kawasaki Disease
Author: Tara Cosgrove, MD, Additional authors*
Background: Kawasaki disease (KD) is an acute childhood vasculitis of unclear etiology that can lead to coronary dilation and aneurysm. Historically, a dichotomous definition for coronary outcomes has existed with either absolute measurements or Z-score cut offs being used to differentiate normal from abnormal coronary outcomes. More recently an intermediate group has been described termed “occult dilation” defined as patients with coronary measurements that remain within the normal range based on Z score, but show reductions in size over time suggesting there was coronary involvement, though to a lesser degree than those with definite dilation.
Objective: We sought to perform a descriptive study to further characterize coronary outcomes in patients with KD when considering those with occult dilation and to examine whether clinical data can predict coronary outcomes.
Methods: A retrospective study was performed of all acute KD patients treated with IVIG from October 2012 through November 2016 at our institution. Patients with serial echocardiograms available up to 12 months after diagnosis were included. The proximal LAD and RCA were measured by a single observer at diagnosis, 2 weeks, 6 weeks and 12 months after diagnosis (Image 1). Values were normalized for body surface area. Patients were divided into 3 groups by coronary outcome: 1) normal = Z score always < 2 with Z score variation <2, 2) occult dilation = Z score variation > 2 with absolute Z score measurements < 2, and 3) definite dilation any Z score > 2. Clinical data (age, sex, ethnicity, CRP level, duration of fever and response to therapy) were analyzed via univariate analysis between each of the coronary outcome groups.
Results: There were 143 patients who met inclusion criteria. 36/143 (25%) of patients had occult dilation, 16/143 (11%) definite dilation and the remaining 93/143 (64%) were normal (Image 2). Trends in coronary measurements are shown in Image 3. Patients who presented with prolonged fever (> 10 days) were more likely to have occult or definite dilation (22% and 31% respectively) compared to those with normal coronaries (8%) (p-value = 0.002). Rate of IVIG resistance increased across coronary outcome groups as degree of coronary involvement increased (normal = 8%, occult dilation = 19%, definite dilation = 44%, p-value = 0.0006). There was no statistically significant difference between coronary outcome groups for age, sex, ethnicity or CRP level.
Conclusion: Occult coronary dilation is a common finding in KD patients who have been previously grouped with those who have completely normal coronary outcomes. Patients with any coronary dilation, occult or definite, were more likely to present with prolonged fever and IVIG treatment resistance. Future longitudinal studies are needed to determine long term outcomes for KD patients with occult coronary dilation.
*Tara Cosgrove MD, The Heart Center, Nationwide Children’s Hospital
Guliz Erdem MD, Infectious Disease, Nationwide Children’s Hospital
Michelle Grcic NP, The Heart Center, Nationwide Children’s Hospital
Preeti Jaggi MD, Infectious Disease, Children’s Healthcare of Atlanta
Kan Hor MD, The Heart Center, Nationwide Children’s Hospital
Karen Texter MD, The Heart Center, Nationwide Children’s Hospital
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