Diagnosis of myocardial syndromes is a challenge in clinical practice because of overlapping forms. Biomarkers for cardiac damage are the cornerstone for the diagnosis and management of the patients admitted for chest pain.

Primary objective is to assess which criteria are used by physicians to make the diagnosis of myocarditis before cardiac MRI and compare them with the results of MRI.

We conducted a retrospective observational and monocentric study from the exhaustive French medico-administrative hospitalizations database records, collected from January 2015 to December 2016 in our center.

A total of 91 patients were included (mean age 38 years, 75.8% male). Diagnosis of myocarditis was immediately suspected in 66% of cases based on the mean age (33 years), previous infectious disease (58%), pericarditis chest pain (87%), ST/T wave change on ECG (78%), and elevation of biomarkers levels: ultra-sensitive (us) Troponin T, creatine kinase (CK) and C-reactive protein (CRP). Eighty-one patients had cardiac MRI, myocarditis was confirmed for 66 patients. Compared with patients with negative MRI, patients were younger (P=0.037) and male (P=0.044). Mean us Troponin T and CK levels were significantly higher (respectively P=0.007 and 0.04). In patients with positive MRI, at the admission, there were significant correlations between CRP and us Troponin T levels (P=0.003, r=0.36), and with CRP levels and ST/T wave change (P=0.02). CRP levels at the admission and left ventricular ejection fraction (LVEF) were poorly correlated (P=0.08, r=−0.002). There was no correlation between us troponin T and LVEF (P=0.44).

Age, male gender, us Troponin and CK levels at the admission are significantly associated with the diagnosis of myocarditis. Besides, it seems to be that CRP levels could provide additional information when compared to us Troponin levels in myocarditis, but these observations have to be confirmed by a larger study.