CMR and serology to diagnose COVID-19 infection with primary cardiac involvement

A 51-year-old man presented with fever, arthromyalgia, dyspnoea, and atypical chest pain, but no coughing or anosmia/ageusia. Troponin I was 2900 ng/mL, N-terminal pro-brain natriuretic peptide (NT-proBNP) was 900 pg/mL, C-reactive protein was 270 mg/L, and fibrinogen was >10 g/L. ECG showed non-specific T wave changes (Panel A). Echocardiography was unremarkable. Acute myocarditis was suspected. Two COVID-19 PCR tests on nasopharyngeal swabs were performed within 48 h, along with a chest CT (Panel B), all being negative for the diagnosis of COVID-19. Serological tests showed ancient parvovirus B19 and Epstein–Barr virus (EBV) infection. Other tests were negative (HBV, HCV, HIV, CMV, Coxsackie, HSV1, HSV2, VZV, VRS, and influenza virus). CMR was performed 8 days after the onset of symptoms, showing subepicardial oedema on the lateral/inferior left ventricular (LV) wall (Panel C), with late gadolinium enhancement (Panel D), consistent with acute myocarditis. Cine imaging showed preserved LVEF and volumes, no wall motion abnormalities, but a 5 mm thrombus was present at the LV apex (Panel E). The unusual finding of a clot despite preserved LVEF and the profound biological signs of inflammation were interpreted as uncommon, and a COVID-19 serological test was thus performed (BIOSYNEX COVID-19). Results were positive for SARS-COV-2 immunization on IgG and IgM. The patient was treated with tocilizumab. This report indicates that (i) myocardial involvement can be the primary manifestation of COVID-19 infection; (ii) CMR may arouse the suspicion of the diagnosis by detecting unusual thrombosis within cardiac chambers; and (iii) serological tests are of the utmost importance to obtain diagnostic confirmation in the absence of pulmonary involvement, as PCR and chest CT may be negative. Conflict of interest: none declared.