https://www.ncbi.nlm.nih.gov/books/NBK459259/
”The mortality rate is up to 20% at 1 year and 50% at 5 years. Despite optimal medical management, overall mortality has not changed in the last 30 years.“
“Acute, nonfulminant myocarditis, conversely, has a more indolent presentation with increased mortality up to 20% in the first year and 55% at 11 years based on initial diagnosis of acute myocarditis."
State of the art: Evaluation and prognostication of myocarditis using cardiac MRI
https://pubmed.ncbi.nlm.nih.gov/30637834/