The objectives of this study were to assess the viral serology of the patients with acute myocarditis and the relation with clinical and CMR parameters at the acute phase and at follow-up.

All cases of infarct-like acute myocarditis, revealed as an acute coronary syndrome with chest pain, elevated troponin levels and confirmed by cardiac magnetic resonance, from 2012 to 2018, were included at Dijon University Hospital. A blood sampling including viral serology is obtained at the time of diagnostic. One-year follow-up included a complete clinical and rhythmic evaluation, and a CMR control.

Among the patients with “infarct like” acute myocarditis, serological analyses were performed in 62 patients. Regarding cardiotropic viruses particularly detected in myocarditis, HHV6 is found in 25 patients (40%), Parvovirus B19 is found in 2 patients (6%) and Coxsackie virus is found in 2 patients (4%). No statistical difference was observed regarding demographic and clinical parameters according the presence or absence of cardiotropic viruses. However, concerning CMR parameters, the extent of myocarditis is more important in the “cardiotropic viruses” group at the acute phase (P=0.05) and at three months (P=0.007) compared to the “no cardiotropic viruses” group (CV+ group: SQS Score in acute phase=10,4–SQS Score at 3 months=6,3 VS CV- group: SQS Score in acute phase=7,3–SQS Score at 3 months=2,7). At one year, there was no significant difference between the two groups regarding CMR parameters.

Cardiotropic viruses (HHV6, Parvovirus B19 and Coxsackie virus) were found in almost 50% of cases in “infarct like” acute myocarditis. According the presence or absence of cardiotropic viruses, CMR parameters were different. Furthermore, use of quantitative PCR (detection of viral genomes) or detection of viral DNA and RNA via in situ hybridization would be a challenge for the future identification of viruses in myocarditis.