CMR Evaluation of Myocardial Inflammation Persistence After Acute Myocarditis: Prognostic Relevance

Patients with acute myocarditis (AM) usually experience spontaneous healing, but a considerable percentage of them evolve towards chronic long-term cardiac impairment. The evolution towards dilated cardiomyopathy (DCM) occurs in a subtle manner, frequently after an initial recover that mimics complete healing. Differences in the course of the disease may reflect the course of underlying myocardial inflammation related to viral clearance or persistence and to the following autoimmune response. Cardiac magnetic resonance (CMR) mapping parameters have been developed for the quantification of edema and necrosis, showing high diagnostic accuracy. No mapping parameter has been developed for the assessment of the third Lake Louise criteria, namely the hyperemia, and, furthermore, their prognostic role is not completely understood. The study hypothesis is that the early-enhanced T1 mapping parameter may have great diagnostic accuracy for myocarditis, and that a short-term monitoring with a complete CMR protocol at 2 month after symptoms onset may identify the subgroup of patients at high risk of progression towards DCM. The results of this study will help to significantly improve diagnostic performances of CMR and may help to manage patients with AM.