Patient Global Impression Questions for Activity-Induced Symptoms in Participants With PAH

Inclusion Criteria: 1. Participant voluntarily gives informed consent to participate in the study. 2. Males and females aged 18 years and above at the time of informed consent. 3. Established primary diagnosis of PAH that is either idiopathic or familial PAH (WHO Group 1), collagen vascular disease associated PAH, PAH associated with HIV infection, PAH induced by anorexigens/toxins, or PAH associated with repaired congenital systemic-to-pulmonary shunts (repaired ≥1 years). 4. Participant is deemed WHO Functional Class 1, 2, or 3. 5. Participant has shortness of breath upon exertion (exhibits a ≥1-point change in Borg dyspnea score) as assessed by the ISWT and a minimum completion of 3 shuttles (30 meters) of the ISWT. Participant may have other symptoms as well. 6. Participant is on stable dose of all FDA-approved PAH treatments (exceptions are anticoagulants and diuretics) for at least 60 days prior to Screening. 7. In the opinion of the Investigator, the participant can communicate effectively with study personnel, and is considered reliable, willing, and likely to be cooperative with protocol requirements. Exclusion Criteria: 1. The participant is known to be pregnant or nursing. 2. The participant has PAH related to any condition not covered under inclusion criteria, including, but not limited to, pulmonary venous hypertension, pulmonary venoocclusive disease, pulmonary capillary hemangiomatosis, chronic thromboembolic pulmonary hypertension, or other conditions under WHO Group 2, 3, 4, and 5 classifications. 3. The participant has evidence of clinically significant left-sided heart disease (including, but not limited to, left ventricular ejection fraction \<40%, left ventricular hypertrophy) or clinically significant cardiologic conditions, such as congestive heart failure, coronary artery disease, or valvular heart disease. 4. The participant has any form of congenital heart disease (repaired or unrepaired; other than a patent foramen ovale). 5. The participant has any ambulatory or orthopedic limitations that would interfere with the ability to perform the activity. 6. The participant has been hospitalized within 30 days of Screening. 7. Current use of prostacyclin analogs/agonists, except inhaled treprostinil, for the treatment of PAH. 8. Use of any other investigational drug/device, or participation in any investigational study with therapeutic intent within 30 days of Screening (concurrent participation in registry studies is allowed). 9. Any other clinically significant illness that, in the opinion of the Investigator, might put the participant at risk of harm during the study or might adversely affect the interpretation of the study data.