Outcomes of Myocarditis in Patients with Normal Left Ventricular Systolic Function on Admission

Area of Science:

• Pediatric Cardiology
• Cardiovascular Inflammation

Background:

• Myocarditis is an inflammatory condition of the heart muscle.
• Assessing outcomes in pediatric myocarditis with preserved left ventricular systolic function is crucial.

Purpose of the Study:

• To describe the clinical characteristics and outcomes of pediatric patients presenting with clinical myocarditis but normal left ventricular (LV) systolic function.
• To evaluate the short-term and one-year outcomes in this specific patient cohort.

Main Methods:

• Retrospective chart review of 75 pediatric patients (aged <19 years) diagnosed with myocarditis between 2008-2012.
• Exclusion criteria included impaired LV systolic ejection fraction (<50%) or fractional shortening (<28%).
• Data collected included presenting symptoms, cardiac biomarkers (BNP, troponin I), ECG findings, cardiac MRI results, therapies, and patient outcomes.

Main Results:

• The cohort (median age 15.5 years) commonly presented with chest pain (75%) and dyspnea (24%).
• Elevated B-type natriuretic peptide (BNP) and troponin I (TnI) were observed in most patients.
• Magnetic resonance imaging (MRI) showed inflammation in 63% of scanned patients; 35% were discharged on heart failure medications.
• Poor outcomes correlated with higher admission BNP, TnI, and creatine kinase levels.

Conclusions:

• Pediatric clinical myocarditis with initially normal LV systolic function carries a potentially higher risk than previously recognized.
• A significant proportion of these patients experience adverse cardiac events, require readmission, or continue heart failure management long-term.
• Further research is warranted to understand the long-term prognosis and optimize management strategies for this population.