Patients and methods70 patients with a recent occurrence of DCM with left ventricle ejection fraction (LVEF) <40% and with the history of symptoms less than 12 months were enrolled to observation. In EMB samples the average number of T-lymphocytes (CD3+ cells) and mononuclear leucocytes (LCA+ cells) in mm2 was determined. The presence of inflammation was evaluated as positive in case of the findings of >7 CD3+ cells and/or >14 LCA+ cells in mm2. The detection of pathological agents in myocardium was performed by quantitative polymerase chain reaction (PCR). ResultsAccording to immunohistological (IH) assessment findings were positive (IH+) in 35 patients (i.e. 50%); thus the inflammatory infiltration was present in myocardium. In remaining patients the findings were negative (IH−). At 6 months follow-up, in the group of IH+ patients the LVEF improved from 25±9% to 39±11% and NYHA class declined from 2.8±0.5 to 1.7±0.6 (both p<0.001). In IH− group change in LVEF (from 23±8% to 27±10%) in contrast to the change of NYHA class (from 2.5±0.5 to 2.1±0.7; p<0.05) was not found statistically significant. Comparing changes in the parameters between both groups, the IH+ group has significantly more improved in LVEF (p<0.01) as well as in the NYHA class (p<0.001). Viral genome was detected (PCR was positive, PCR+) in 43 patients (i.e. 61%). At 6 months follow-up, there were statistically significant changes of LVEF in PCR+ group (from 25±8% to 34±12%; p<0.01) and also in PCR− group (from 22±8% to 32±12%; p<0.001). The difference in changes of LVEF between these two groups was not statistically significant. Change in NYHA class was statistically significant and comparably reduced in both groups (from 2.6±0.5 to 1.9±0.6; p<0.001; and from 2.7±0.6 to 2.0±0.7; p<0.001, respectively). ConclusionPatients with a recent occurrence of non-ischemic LV dysfunction and biopsy proven myocarditis have been found to show statistically significant improvement in the LV systolic function and functional status in comparison to the group of patients with no evidence of inflammatory infiltration in 6-month follow-up. On the contrary, the presence or absence of viruses in the myocardium has no impact on the changes in these parameters.