Therapeutics
EMILY DUAN, MD
Resident physician
UCLA, United States
Background:
A subset of patients with KD are refractory to standard treatments and have an increased risk of cardiac complications. We present a case of giant CA aneurysms and thrombosis in an infant with unusually severe KD.
History A 4 month old full-term male presents with an episode of apnea and cyanosis requiring chest compressions at home. Two weeks prior he had developed a cough, congestion, and fever for one day. Initial work-up revealed elevated inflammatory markers (WBC 40, Plt 1,264, CRP 15.6 mg/dL, Procalcitonin 0.34 ug/L) and normal EEG, MRI brain, and CSF studies. He subsequently went into cardiac arrest requiring cannulation onto veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Due to high suspicion for post-infectious inflammatory conditions affecting the myocardium, an echo was obtained and showed a small pericardial effusion and reduced biventricular systolic function. Cardiac catheterization revealed a right coronary artery aneurysm with complete thrombosis and numerous giant left coronary artery aneurysms. Based on the CA aneurysms (CAA) and laboratory criteria he was diagnosed with atypical KD. His treatment included IVIG, steroids, and IL-1 antagonists due to severe coronary inflammation, and dual antiplatelet therapy and enoxaparin for comprehensive anticoagulation. Given the high risk of cerebral hemorrhage while being anticoagulated on VA-ECMO, he did not receive tPA. He had rapid improvement in cardiac function and was decannulated off VA-ECMO within 4 days. CT imaging 3 weeks later showed stably dilated CAs, but no intra-aneurysmal filling defects within a portion of the left anterior descending artery, suggestive of thrombus resolution. Upon discharge the patient was alert and active with normal biventricular function. KD is the most common cause of acquired pediatric heart disease. Increased platelet count and activation is associated with IVIG resistance and coronary artery aneurysms. Mouse models demonstrate that platelets increase vascular inflammation through increased IL-1 production and contribute to acute ischemic disease, suggesting that anti-Il-1 agents may be used in the treatment of severe KD. Young infants have fewer manifestations of typical KD symptoms leading to delayed diagnoses and increased incidence of CAA. A high index of suspicion for KD in febrile young infants is necessary to prevent CAA’s. Conclusion Our patient’s case was unusual due to his age, severity, and rapid clinical improvement. It highlights the use of anti-IL-1 agents and conservative management of CA thrombosis without thrombolysis for a patient with atypical KD, and emphasizes the importance of comprehensive evaluations of infants with nonspecific symptoms. Discussion