Clinical Characteristics and Outcome of Biopsy-Proven Myocarditis in Children – Results of the German Prospective Multicentre Registry 'MYKKE'

Background: Heart failure (HF) due to myocarditis might not respond in the same way standard therapy as HF other aetiologies. The aim of this study was investigate value endomyocardial biopsies (EMB) for clinical decision-making and its relation outcome paediatric patients with myocarditis. Methods: Clinical EMB data children collected MYKKE-registry between 2013 2020 from 23 centres were analysed. studies included histology, immunohistology, molecular pathology. occurrence major adverse cardiac events (MACE) including mechanical circulatory support (MCS), heart transplantation, and/or death defined a combined endpoint. Results: Myocarditis diagnosed 209/260 patients: 64% healing/chronic lymphocytic myocarditis, 23% acute (AM), 14% healed no giant cell myocarditis. median age 12.8 (1.4-15.9) years. Time symptom-onset 11.0 (4.0-29.0) days. Children AM high amounts mononuclear infiltrates significantly younger signs compared those or Myocardial viral DNA/RNA detection had significant effect on outcome. worst event-free survival seen (24%), followed by (31%) (58%, p=0.294). A weaning rate MCS found AM. Conclusions: provides important information type stage myocardial inflammation supports further decision-making. fulminant presentation, young have highest risk MACE.