Sildenafil improves endothelial function in patients with pulmonary hypertension

BackgroundSildenafil has been shown to be effective in the treatment of pulmonary hypertension, and has favourable effects on endothelial function. Our hypothesis is that a part of the beneficial effects of sildenafil in patients with pulmonary hypertension is due to the improvement of the endothelial function.MethodsNine patients (seven females, age 67±9 years) with thromboembolic pulmonary hypertension were treated with sildenafil, at a mean dose of 150±75 mg/die. At baseline and after 6 months all patients underwent: right-heart catheterization, 6-min walking distance, and a study of endothelial function, including the measure of the flow-mediated vasodilation of the brachial artery, and the dosage of plasma levels of endothelin-1 and von Willebrand factor.ResultsDuring follow-up we found a significant reduction of mean pulmonary artery pressure and arteriolar resistances. Accordingly, the functional capacity improved (an average of+37 m). Sildenafil improved endothelial-dependent vasodilation and reduced plasma concentrations of endothelin-1 (from 4.5±0.6 to 3.1±0.7 pg/mL; p<0.0001) and von Willebrand factor (from 183.1±10.1 to 149.1±17.6 mU/mL; p<0.0001).ConclusionImprovement of the endothelial function may represents one of the mechanisms able to explain the favourable effects sildenafil has shown in patients with pulmonary hypertension.