Study of Incidence of Respiratory Tract AEs in Patients Treated With Tyvaso® Compared to Other FDA Approved PAH Therapies

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.