EC did not accept measurement of patient's activity for the primary end-point with a non-validated activity tracking device

The objective of the study is to monitor physical activity longitudinally with a wrist activity tracker specifically in PAH patients newly initiating ERA therapy and to assess the correlation with the 6MWD at different time points. Further objectives are to assess the correlation of physical activity measured with the tracker and other parameters for clinical evaluation and right ventricular function assessment (i.e. Biomarkers, WHO Functional class, hospitalization due to PAH, Echochardiography and Quality of Life) as well as sleep efficacy in PAH patients newly initiating ERA therapy.

Inclusion Criteria:

• Male or female patients with right heart catheter (RHC)-confirmed PAH (WHO PH group I)
• Age ≥18 year
• Not receiving ERA therapy in the 30 days prior to the enrolment visit
• Signed patient informed consent form

Exclusion Criteria:

• Patient with conditions that prevent compliance with the protocol or to adhere to therapy and use of the device

Patients diagnosed with PAH, and not receiving ERA therapy in the 30 days prior to the enrolment visit, are eligible for inclusion in this study. Patients in need of ERA therapy will receive ERA treatment according to the physician's decision