Clinical Trials

This study will investigate the effects of the combination of bosentan and sildenafil. Patients with symptomatic PAH treated with a stable dose of sildenafil equal to or greater tha 20 mg t.i.d. for at least 12 weeks will be randomized to placebo or bosentan 125 mg b.i.d. All randomized patients will be treated with study drug until the predefined target number of morbidity/mortality events is reached.

Cardiac magnetic resonance imaging has emerged as a potential valuable test for the early detection of Pulmonary Arterial Hypertension. A number of reports have provided some preliminary evidence that Pulmonary Artery (PA) stiffness may be accurately detected by imaging of the pulmonary artery in order to measure PA stiffness. In addition, cardiac MRI could play provide early and effective treatment for Pulmonary Arterial Hypertension (PAH).

A post marketing surveillance to determine the type and incidence of oro/nasopharyngeal or pulmonary adverse events that may occur in patients treated with commercially available Tyvaso®(treprostinil) Inhalation Solution. A comparison will be made to the type and incidence of events in patients receiving other FDA approved therapies for pulmonary arterial hypertension, as a control measure.