Effect of losartan on cardiac function and secretion of nitric oxide andendothelin in patients with congestive failure

Aim To evalute the effects of losartan on the cardiac function and secretion of nitric oxide(NO)and endothelin(ET)in patients with congestive heart failure(CHF).Methods Sixty patients with class Ⅱ～Ⅳ CHF were randomised to receive a 12 weeks of routine therapy either with losartan(n=30)to be added from 25 mg to 50 mg daily or with enalapril(n=30)to be added from 2.5 mg to 5 mg daily. The cardiac systolic and diastolic funtion and the levels of NO and ET were observed before and after therapy respectively, with 30 normal control subjects seving as control. Results The abnormal cardiac systolic and diastolic function parameter were present in patients with CHF. The ET and NO levels in CHF patients were significantly higher than those in the control group(P0.05).NYHA function class was improved in 85% of losartan_treated patients and in 84% of enalapril_treated patients after 12 weeks,as compared with cardiac function at baseline. ET and NO levels were significantly reduced(P0.01),NO/ET ratio was increased(P0.05) after 12 weeks of therapy in two active groups. Conclusion The systolic and diastolic functions of patients with CHF are greatly improved by losartan treatment,which reverses the imbalance of NO/ET and it is suspected that this action may be another important mechanism of its treating heart failure.