This prospective, non-interventional, multi-center study documents observational data on subjects under routine treatment of Pulmonary Arterial Hypertension, functional class III with inhaled Iloprost administered with I-Neb AAD (Adaptive Aerosol Delivery) device. The observation period for each subject covers a one year treatment period with inhaled Ventavis. For each subject, the investigator or a delegate collects data as defined in the case report form at an initial visit, routine follow-up visit at 6 months and final visit at 12 months.

Inclusion Criteria:

• Male or female subjects aged ≥18 years
• Newly Treated with Ventavis or treated with Ventavis for less than 6 months, with I Neb AAD device for the application, as described in the SmPC (Summary of Product Characteristics), complemented by the Insight
• With Pulmonary Arterial Hypertension, Group I of the Dana point Pulmonary Hypertension Classification.
• WHO (World Health Organization) /NYHA (New York Heart Association) Functional class III
• Able and willing to give written informed consent for participation in the study

Exclusion Criteria:

Key contra indications:

• Hypersensitivity to the active substance or to any of the excipients.
• Conditions where the effects of Ventavis on platelets might increase the risk of haemorrhage (e.g. active peptic ulcers, trauma, intracranial haemorrhage).
• Severe coronary heart disease or unstable angina;
• Myocardial infarction within the last six months;
• Decompensated cardiac failure if not under close medical supervision;
• Severe arrhythmias;
• Cerebrovascular events (e.g. transient ischaemic attack, stroke) within the last 3 months.
• Pulmonary hypertension due to venous occlusive disease.
• Congenital or acquired valvular defects with clinically relevant myocardial function disorders not related to pulmonary hypertension

Patients aged ≥18 years and diagnosed with PAH (Pulmonary Arterial Hypertension), WHO/NYHA functional class III, Group I of the Dana point Pulmonary Hypertension Classification and newly Treated with Ventavis or treated with Ventavis for less than 6 months, with I-Neb AAD device for the application.