Comparative effects of valsartan and enalapril on cardiac sympathetic nerve activity and plasma brain natriuretic peptide in patients with congestive heart failure

OBJECTIVE: To evaluate the effects of valsartan on cardiac sympathetic nerve activity, plasma brain natriuretic peptide (BNP) concentration, cardiac function, and symptoms in patients with congestive heart failure (CHF) by comparison with those of enalapril. METHODS: 50 patients with CHF (left ventricular ejection fraction (LVEF) < 40%) were randomly assigned to valsartan (80 mg/day; n = 25) or enalapril (5 mg/day; n = 25). All patients were also treated with a loop diuretic. The delayed heart to mediastinum count (H/M) ratio, delayed total defect score (TDS), and washout rate were determined from (123)I-meta-iodobenzylguanidine (MIBG) images. Plasma BNP concentrations were measured before and after six months of treatment. The left ventricular end diastolic volume (LVEDV) and LVEF were also determined by echocardiography. RESULTS: In patients receiving valsartan, TDS decreased from a mean (SD) of 43 (8) to 39 (10) (p < 0.01), H/M ratio increased from 1.70 (0.17) to 1.78 (0.22) (p < 0.05), washout rate decreased from 46 (11)% to 41 (10)% (p < 0.05), and plasma BNP concentration decreased from 237 (180) pg/ml to 143 (93) pg/ml (p < 0.05). In addition, LVEDV decreased from 172 (42) ml to 151 (45) ml (p < 0.05) and LVEF increased from 31 (7)% to 39 (10)% (p < 0.001). However, these parameters did not change significantly in patients receiving enalapril. CONCLUSION: Plasma BNP concentration and (123)I-MIBG scintigraphic and echocardiographic parameters improved significantly after six months of treatment with valsartan. These findings indicate that valsartan can improve cardiac sympathetic nerve activity and left ventricular performance in patients with CHF.