Myocarditis and Kawasaki disease

Area of Science:

• Pediatric Cardiology
• Rheumatology
• Immunology

Background:

• Kawasaki disease (KD) is the leading vasculitis in children.
• Cardiovascular complications, including myocarditis and coronary artery aneurysms, are frequent in KD.
• While histological myocarditis is universal in KD, clinical symptoms are less common.

Purpose of the Study:

• To investigate the prevalence and characteristics of myocarditis in children with Kawasaki disease.
• To evaluate the impact of treatment on cardiac function in KD patients.
• To identify potential long-term cardiac sequelae of KD-associated myocarditis.

Main Methods:

• Histological examination of cardiac tissue from KD patients.
• Echocardiographic assessment of cardiac function, including systolic and diastolic parameters, strain, and dimensions.
• Comparison of echocardiographic findings and recovery between patients treated with intravenous immunoglobulin (IVIG) and aspirin versus aspirin alone.

Main Results:

• Histological evidence of myocarditis is present in all KD patients.
• Echocardiography reveals systolic dysfunction (depressed shortening fraction), increased ventricular dimensions, and diastolic dysfunction in a significant proportion of patients.
• Echocardiographic signs of myocarditis resolve more rapidly with IVIG treatment compared to aspirin alone.
• Systolic function typically normalizes long-term, but subtle abnormalities in strain and diastolic function may persist.
• Myocarditis can occur independently of coronary artery abnormalities.

Conclusions:

• Myocarditis is a universal finding in Kawasaki disease, presenting with varied clinical and echocardiographic manifestations.
• Intravenous immunoglobulin therapy accelerates the echocardiographic recovery of cardiac function in KD patients.
• While significant cardiac dysfunction often resolves, persistent subtle abnormalities underscore the potential for long-term sequelae from KD myocarditis.