Comparing losartan with enalapril in congestive heart failure

We compared the effects of losartan and enalapril on exercise oxygen uptake, diffusing capacity of lung for carbon monoxide, and evaluated the consequences of cyclo-oxygenase and prostaglandin inhibition in 16 patients with congestive heart failure and 8 controls. In patients, but not in controls, losartan and enalapril similarly improved exercise tolerance and oxygen uptake. This effect was inhibited, however, by cyclooxygenase blockade with aspirin while patients were taking enalapril and not losartan. Our findings suggest that because losartan's effect is dissociated from prostaglandin activation, it may be an advancement for the treatment of patients with congestive heart failure and coronary artery disease in whom aspirin is indicated.