Pulmonary arterial hypertension is a devastating progressive disease increasingly debilitating symptoms. In the past few years, treatment of pulmonary hypertension has undergone an extraordinary evolution. A selective PDE-5 inhibitor, Sildenafil, has been shown to be as an effective pulmonary vasodilator as inhaled NO in patients with primary pulmonary hypertension and has recently been shown to improve exercise capacity, resting hemodynamics, and WHO functional class in patients with pulmonary hypertension. However, to date, the effect of Sildenafil have been mainly studied in patients with advanced disease.~Udenafil (Zydena), a newly developed PDE-5 inhibitor, has been proved to have similar efficacy and safety profile, compared with other PDE-5 inhibitors. However, to date, the effect of Udenafil in mild pulmonary HT has never been evaluated. Therefore, we hypothesized that Udenafil, a newly developed phosphodiesterase type 5 inhibitor, would improve symptom, exercise capacity and hemodynamic status in patients with mild pulmonary hypertension.~In this 12-week, randomized, double-blind, placebo-controlled trial, patients with mild pulmonary hypertension will be enrolled according to the eligibility criteria. After randomization, study participants will be assigned to receive either 50mg of Udenafil or placebo two times a day for 4 weeks, and then the dosage will be doubled to 100mg two times a day for next 8 weeks. Participants will attend study visits at baseline and weeks 4 and 12. Physical examination, medical history review, blood sample collection and electrocardiogram will be conducted on each study visits. At baseline and week 12, participants will undergo cardiopulmonary exercise test and exercise echocardiography. At every study visits, researchers will collect health information.
The investigators hypothesized that udenafil, a newly developed phosphodiesterase type 5 inhibitor, would improve symptom, exercise capacity and hemodynamic status in patients with mild pulmonary hypertension.