Cardiac magnetic resonance findings in acute and post-acute COVID-19 patients with suspected myocarditis

Introduction: Cardiac injury is commonly reported in COVID-19 patients, resulting associated to pre-existing cardiovascular disease, disease severity, and unfavorable outcome. Aim is to report cardiac magnetic resonance (CMR) findings in patients with myocarditis-like syndrome during the acute phase of SARS-CoV-2 infection (AMCovS) and post-acute phase (cPACS). Methods: Between September 2020 and January 2022, 39 consecutive patients (24 males, 58%) were referred to our department to perform a CMR for the suspicion of myocarditis related to AMCovS (n = 17) and cPACS (n = 22) at multimodality evaluation (clinical, laboratory, ECG, and echocardiography). CMR was performed for the assessment of volume, function, edema and fibrosis with: standard sequences and mapping techniques. CMR diagnosis and the extension and amount of CMR alterations were recorded. Results: Patients with suspected myocarditis in acute and post-COVID settings were mainly men (10 (59%) and 12 (54.5%), respectively) with older age in AMCovS (58 [48-64]) compared to cPACS (38 [26-53]). Myocarditis was confirmed by CMR in most of cases: 53% of AMCovS and 50% of cPACS with negligible LGE burden (3 [IQR, 1-5] % and 2 [IQR, 1-4] %, respectively). Myocardial infarction was identified in 4/17 (24%) patients with AMCovS. Cardiomyopathies were identified in 12% (3/17) and 27% (6/22) of patients with AMCovS and cPACS, including DCM, HCM and mitral valve prolapse. Conclusions: In patients with acute and post-acute COVID-19 related suspected myocarditis, CMR improves diagnostic accuracy characterizing ischemic and non-ischemic injury and unraveling subclinical cardiomyopathies.