Findings and Outcome of Transcatheter Right Ventricular Endomyocardial Biopsy and Hemodynamic Assessment in Children with Suspected Myocarditis or Cardiomyopathy.

OBJECTIVE

The study objective is assessing findings and outcome in children with suspected cardiomyopathy (CMP) or myocarditis undergoing cardiac catheterization with transcatheter right ventricular endomyocardial biopsy (RV-EMB).

METHODS

All consecutive children undergoing cardiac catheterization with RV-EMB for suspected CMP/myocarditis between 2002-2021 were analysed regarding clinical presentation, cardiac biomarkers, periprocedural management, hemodynamic, histological/immunohistological findings, and outcome.

RESULTS

Eighty-five RV-EMBs were performed in 81 patients at a median age of 6.8 (IQR 9.9) years and a bodyweight of 20 (32.2) kg. Histological/immunohistological findings of RV-EMB revealed dilated CMP in 10 (12%), chronic myocarditis in 28 (33%), healing myocarditis in 5 (6%), acute myocarditis in 9 (11%), other heart muscle diseases in 23 (27%) (7 restrictive CMP, 5 hypertrophic CMP, 4 toxic/anthracycline-induced CMP, 4 endocardfibroelastosis, 1 arrhythmogenic right ventricular CMP, 1 laminin CMP, 1 haemangioma), no conclusive histology in 7 (8%), and normal histology in 3 (4%) patients. Median LVEDP was 17 mmHg (IQR 9), LAP 15 mmHg (10), and PVR 1.83 (1.87) Wood Units/m2. There were 3 major complications (3%), all patients recovered without any sequelae. At follow-up (median 1153, IQR 1799 days) 47 (59%) patients were alive, 11 (13%) dead, 15 (18%) underwent cardiac transplantation, and 8 (9%) were lost to follow-up. Death/cardiac transplantation occurred within 3 years from RV-EMB. All patients with an acute myocarditis survived. NT-pro-BNP, echo parameters, and invasive hemodynamics correlate independently with death/cardiac transplant.

CONCLUSION

Hemodynamic invasive data and morphological findings in RV-EMB complete clinical diagnosis in children with suspected CMP/myocarditis and provide important information for further clinical management.