RESUMO
Although a cornerstone in the treatment of heart failure, angiotensin-converting enzyme inhibitors are under-used, partly due to side effects. If proven at least similarly efficacious to angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers may replace them due to their superior tolerability. We aimed to compare the efficacy and safety of valsartan and enalapril in heart failure patients stabilised on an angiotensin-converting enzyme inhibitor. We randomised 141 patients (mean 68 years, 74% males) with stable mild/moderate heart failure and left ventricular ejection fraction 0.45 or less, to valsartan 160 mg q.d. (n=70) or enalapril 10 mg b.i.d. (n=71) for 12 weeks. Changes in 6-min-walk test (primary efficacy variable), patients' wellbeing and left ventricular size and function did not differ significantly between the treatment groups. Valsartan was significantly non-inferior to enalapril in walk test distance change: least-square means treatment difference +1.12 m (95% confidence interval -21.9 to 24.1), non-inferiority P<0.001. Left ventricular size (P<0.001) and function (P=0.048) improved significantly only in the valsartan group. Fewer patients experienced adverse events in the valsartan group (50%) than in the enalapril group (63%), although statistically non-significant. Valsartan is similarly efficacious and safe to enalapril in patients with stable, mild/moderate heart failure, previously stabilised on an angiotensin-converting enzyme inhibitor and directly switched to study medication.