Patient aged ≥ 18 years Patient (or patient's legally authorized representative) is willing and able to provide written informed consent Patient is willing and able to comply with the protocol, including required follow-up visits Patient is diagnosed with Pulmonary Arterial Hypertension (World Health Organization (WHO) Category Group 1 (by the WHO Clinical classification system), including Idiopathic (IPAH), Heritable PAH (HPAH) (Familial PAH), and PAH associated with other diseases (APAH), Patient is receiving continuous infusion of treprostinil via subcutaneous or intravenous delivery using an external pump system Patient is in stable clinical condition und the previous specific PH medication has been retained unchanged during the past 3 weeks Patient's anticoagulation therapy can be managed to permit safe device implantation