A Patient Registry to Observe the Real-World Dosing and Titration of Tyvaso®

This prospective, observational, multi-center, patient registry will follow patients who are newly initiated on Tyvaso for the treatment of Pulmonary Arterial Hypertension (PAH). Once enrolled, the patients' dose and titration will be followed for the first 6 months of treatment with Tyvaso. A call-center will contact the patients directly at weeks 1, 2, 3, 4, 8, 12, 16, 20, and 24 to review their dose and titration schedule. In addition to patient-reported dosing data, some patient demographic information, will be collected by the investigative site at Baseline.