Background: Although the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in patients with heart failure are well recognized, there are theoretical advantages in combining ACE inhibition with angiotensin (AT)1 receptor antagonism.
Methods: Twenty patients with mild to moderate heart failure and maximally treated with an ACE inhibitor were randomly assigned to losartan or placebo. Patients underwent repeated assessment of exercise tolerance, quality of life, central and regional hemodynamics, and neurohumoral and biochemical parameters over a period of 12 weeks.
Results: Losartan treatment was well tolerated in terms of adverse events, heart rate, and blood pressure response, and there were no significant changes in serum creatinine or potassium. After 12 weeks of treatment, no significant differences were observed between the losartan and placebo groups in exercise tolerance, quality of life, central and regional hemodynamics, or neurohumoral parameters.
Conclusions: In patients with mild to moderate heart failure already maximally treated with an ACE inhibitor, additional treatment with losartan is well tolerated, but we have not observed any significant improvement in exercise capacity, quality of life, central and regional hemodynamics, or neurohormones. Our data suggest that the combination of losartan with an ACE inhibitor does not offer any substantial advantages over treatment with an ACE inhibitor alone in these patients.