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.

Optical coherence tomography for characterization of cardiac allograft vasculopathy in late survivors of pediatric heart transplantation.

BACKGROUND: Optical coherence tomography (OCT) has been shown to reliably detect cardiac allograft vasculopathy (CAV). In recent studies performed in adult heart transplant (HTx) recipients, OCT revealed the presence of vulnerable plaques and complicated coronary artery lesions, thus challenging the current concept that CAV disease is a diffuse concentric and fibrosing vasculopathy. The aim of our study was to characterize CAV by OCT in a young population of HTx recipients. METHODS: We prospectively enrolled 21 young HTx recipients (mean age 27 years, range 22 to 38 years) to undergo OCT of the left anterior descending coronary artery (LAD) in addition to annual CAV screening by coronary angiography and virtual histology intravascular ultrasound (VH-IVUS). Quantitative OCT analysis was performed at the site of maximal intimal thickness (MIT) for each LAD segment. RESULTS: Patients were 27 years old with a mean time from cardiac transplantation of 14.7 ± 6.8 years. All patients exhibited intimal hyperplasia with an abnormal (>1) intima-to-media ratio. The median (interquartile range) MIT values by OCT were 0.37 (0.22 to 0.54) mm, 0.46 (0.29 to 0.54) mm and 0.34 (0.25 to 0.49) mm in the distal, middle and proximal LAD segments, respectively. Qualitative OCT analysis rarely showed features of vulnerable plaque or complicated lesions. Consistently, at VH-IVUS, the prevalent component at the site of MIT per vessel assessed by OCT was fibrous tissue. CONCLUSIONS: Unlike recent evidence in adult HTx recipients, OCT findings of vulnerable plaque and complicated coronary lesions were found to be rare among late survivors of pediatric HTx.