Patients with myocarditis and left ventricular (LV) dysfunction may improve after standard heart failure therapy. This improvement seems to be related to retreat of myocardial inflammation. The aim of the present study was to assess changes in clinical, echocardiographic and some laboratory parameters and to correlate them with changes in the number of inflammatory infiltrating cells in endomyocardial biopsy (EMB) samples during the 6-month follow-up, and to define predictors of LV function improvement among baseline parameters. Forty patients with biopsy-proven myocarditis and impaired LV function (LV ejection fraction-LVEF <40 %) with heart failure symptoms ≤ 6 months were evaluated. Myocarditis was defined as the presence of >14 mononuclear leukocytes/mm(2) and/or >7 T-lymphocytes/mm(2) in the baseline EMB. The EMB, echocardiography and clinical evaluation were repeated after 6 months of standard heart failure therapy. LVEF improved on average from 25 ± 9 to 42 ± 12 % (p < 0.001); LV end-systolic volume and LV end-diastolic volume (LVEDV) decreased from 158 ± 61 to 111 ± 58 ml and from 211 ± 69 to 178 ± 63 ml (both p < 0.001). NYHA class decreased from 2.6 ± 0.5 to 1.6 ± 0.6 (p < 0.001) and NTproBNP from 2892 ± 3227 to 851 ± 1835 µg/ml (p < 0.001). A decrease in the number of infiltrating leukocytes (CD45+/LCA+) from 23 ± 15 to 13 ± 8 cells/mm(2) and in the number of infiltrating T lymphocytes (CD3+) from 7 ± 5 to 4 ± 3 cells/mm(2) (both p < 0.001) was observed. The decline in the number of infiltrating CD45+ cells significantly correlated with the change in LVEF (R = -0.43; p = 0.006), LVEDV (R = 0.39; p = 0.012), NYHA classification (R = 0.35; p = 0.025), and NTproBNP (R = 0.33; p = 0.045). The decrease in the number of CD3+ cells correlated with the change of systolic and diastolic diameters of the left ventricle (R = -0.33; p = 0.038 and R = -0.45; p = 0.003) and with the change in LVEDV (R = -0.43; p = 0.006). Tricuspid annular plane systolic excursion (TAPSE) (OR 0.61; p = 0.005) and early transmitral diastolic flow velocity (E wave) (OR 0.89; p = 0.002) were identified as predictors of LVEF improvement. Improvements in clinical status, LV function and NTproBNP levels correlated with decrease in the number of infiltrating inflammatory cells. TAPSE and E wave velocity were significant predictors of improvement in multivariate regression. Our observations suggest that contemporary guidelines-based therapy of heart failure is an effective treatment option in patients with recent onset biopsy-proven inflammatory cardiomyopathy.
Keywords: Echocardiography; Endomyocardial biopsy; Inflammatory cardiomyopathy; Left ventricular dysfunction; Myocarditis.