120 - DELAYED-ONSET SEVERE BIVALVULAR INSUFFICIENCY IN KAWASAKI DISEASE WITH GIANT CORONARY ANEURYSMS: A CASE REPORT

Introduction: Although the most common complication in KD remains CA dilation, valvular manifestations can occur during the acute phase. We present a case of a 3-year-old with severe KD, and late-onset bivalvular involvement leading to surgical intervention.

Case Report: At the diagnosis of typical KD, giant coronary aneurysms (GCAs) affecting the left main CA (Z-score +9.6); left anterior descending (Z-score +11.6); and proximal right CA (Z-score +7.6) were identified. Immunomodulatory therapy was initiated, including IVIG, steroids, Anakinra, and Tocilizumab. The child received long-term anticoagulation with VKA and aspirin.

Follow-up: Echocardiography revealed rapidly progressive aortic and mitral regurgitation, first manifesting 4 months after disease onset (Fig. 1). Cardiac MRI at the 6-month mark confirmed worsening aortic (regurgitant fraction 31%) and mitral (RF 26%) insufficiencies with left ventricular dilation (148 mL/m2). Surgical intervention was conducted 11 months post-diagnosis: perioperative surgical observations (Fig. 2) found, at the aortic level, redundant tissue with commissural retraction and fenestrations of the left cusp (Fig. 3). The mitral valve showed a hemmed appearance with dense nodular formations on valve leaflets. Of note, the aortic wall showed changes (yellow and thickened vascular wall) as seen in hypercholesterolemia. Lipid profiling found elevated LDL-cholesterol levels in the patient and combined hyperlipidemia in the patient's father.

This unique case presents a rare complication of severe KD with bivalvular inflammatory lesions and giant coronary aneurysms. Both aortic and mitral regurgitation were attributed to direct valvulitis, with independent progression of valvular inflammation despite systemic control. Perioperative exploration found anatomical manifestations of hypercholesterolemia - although potentially consequential to prolonged inflammation rather than causative, the macroscopic changes to the vasculature encourage extreme caution in the management of these patients who will remain at high risk of CA disease. While screening for inflammatory disease-associated variants was negative, recent studies support the theory of subgroups of subjects prone to atypically severe vascular manifestations, suggesting vascular-oriented genomic screening as a new avenue of research.

Conclusion: This unique case emphasizes the need for comprehensive and long-term follow-up in severe KD cases, especially those with refractory disease and atypical presentations. Persistent high-level inflammation results in rapidly progressing degeneration of tissue, with features reminiscent of lesions found in adult patients after decades of atherosclerotic stress. Possible short-term implications include independently progressive valvulitis, which can warrant surgical management.