In our study, perforin-positive cardiac inflammation was associated with worse outcome in a multivariate analysis adjusted for sex and age, recapitulating earlier findings by Escher et al. [49] Evidence of any type of cardiac inflammation in EMB, regardless of severity, was not associated with all-cause mortality in our population which was not preselected for high pretest probability of (post)myocarditis. This evidence concerns the gene PRF1 and myocarditis.