Clinical and Cardiac Magnetic Resonance Findings in Post-COVID Patients Referred for Suspected Myocarditis

Objectives: We assessed possible myocardial involvement in previously cardiac healthy post-COVID patients referred for persisting symptoms with suspected myocarditis.

Background: Prior studies suggested myocardial inflammation in patients with coronavirus-induced disease 2019 (COVID-19). However, the prevalence of cardiac involvement among COVID patients varied between 1.4 and 78%.

Methods: A total of 56 post-COVID patients without previous heart diseases were included consecutively into this study. All patients had positive antibody titers against SARS-CoV-2. Patients were referred for persistent symptoms such as chest pain/discomfort, shortness of breath, or intolerance to activity. All patients underwent standardized cardiac assessment including electrocardiogram (ECG), cardiac biomarkers, echocardiography, and cardiac magnetic resonance (CMR).

Results: 56 Patients (46 ± 12 years, 54% females) presented 71 ± 66 days after their COVID-19 disease. In most patients, the course of COVID-19 was mild, with hospital treatment being necessary in five (9%). At presentation, patients most often reported persistent fatigue (75%), chest pain (71%), and shortness of breath (66%). Acute myocarditis was confirmed by T1/T2-weighed CMR and elevated NTpro-BNP levels in a single patient (2%). Left ventricular ejection fraction was 56% in this patient. Additional eight patients (14%) showed suspicious CMR findings, including myocardial edema without fibrosis (n = 3), or non-ischemic myocardial injury suggesting previous inflammation (n = 5). However, myocarditis could ultimately not be confirmed according to 2018 Lake Louise criteria; ECG, echo and lab findings were inconspicuous in all eight patients.

Conclusions: Among 56 post-COVID patients with persistent thoracic complaints final diagnosis of myocarditis could be confirmed in a single patient using CMR.