. NYHA FC, 6-min walking test (6MT), QOL, 2D-echocardiography, plasma renin activity (PRA), angiotensin II (AT-II), aldosterone (Ald), norepinephrine (NE), epinephrine (E), brain natriuretic peptide (BNP) concentrations and 24-hour HRV parameters were investigated at baseline, 3 and 6 months after randomization.