Comparative effects of losartan and nifedipine therapy on exercise capacity, Doppler echocardiographic parameters and endothelin levels in patients with secondary pulmonary hypertension.

OBJECTIVE: Pulmonary hypertension (PHT) is associated with high mortality and morbidity. Interest has increased in the use of drugs that, because of their neurohumoral inhibitory effects, inhibit the renin angiotensin system. In this study, we sought to examine whether losartan therapy is non-inferior to nifedipine in the treatment of secondary PHT. METHODS: This prospective randomized study consisted of 63 patients (mean age, 63.7+/- 9.1 years) with PHT who underwent Doppler echocardiographic examination. A baseline 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were performed, and the endothelin-1 level of each patient was measured. Patients were assigned to two groups receiving treatment with nifedipine (n=30) and losartan (n=33). After 2 months of treatment, those measurements were repeated. The groups were compared with regard to effectiveness for the studied parameters using 2*2 factorial ANOVA design for repeated measurements. RESULTS: When posttreatment values were compared with baseline values in both groups, the following statistically significant changes were noted: the mean values of both mean and systolic pulmonary artery pressures (PAPs) were reduced (p 0.05). CONCLUSION: The findings of this study indicate that losartan is non-inferior to nifedipine for reducing PAP and improving exercise capacity. However, the short-term use of losartan or nifedipine had no statistically significant effect on endothelin-1 levels in patients with secondary PHT.