Endomyocardial biopsy safety and clinical yield in pediatric myocarditis: An Italian perspective

Objectives: The objective of this investigation is to evaluate the safety, the impact of endomyocardial biopsy (EMB) results in myocarditis management and the incidence of different etiologies of myocarditis in a pediatric population. Background: Although EMB is an established diagnostic tool to evaluate suspected myocarditis, there is lack of clear diagnostic and management guidelines for myocarditis in pediatric patients, particularly in infants. Methods: We performed a retrospective database review and subsequent outcomes analysis from five Italian pediatric cardiology centers to identify patients aged 0-18 years who underwent EMB for suspected myocarditis or inflammatory cardiomyopathy (ICMP) between 2009 and 2011. Results: EMB was performed in 41 children, of which 16 were male. The population ranged between 16 days of age to 17 years (mean age at EMB=5.2±4.9 years). The overall incidence of EMB-related complications was 15.5% (31.2% in infants, and 6.8% in children>1 year of age; P=0.079) while the incidence of EMB-driven treatment changes was 29.2%. Histological examination together with PCR on heart biopsy specimens allowed an etiological diagnosis in 26/41 patients (63%). Among the 15 patients (36.5%) with diagnosis of dilated cardiomyopathy (DCM) 11 had idiopathic DCM. Finally, we found an overall incidence of death/cardiac transplantation of 24%. Conclusions: In a pediatric population with suspected myocarditis/ICMP, EMB was useful in confirming the diagnosis only in 41% of cases but showed an overall diagnostic power of 63%. As complications of EBM are not negligible, particularly in infants, the risk/benefit ratio should be taken into account in each patient.