Overview Upfront Combination Pulmonary Arterial Hypertension Therapy Status: Recruiting Trial end date: 2021-01-31 Target enrollment: Participant gender: Summary To evaluate the safety and efficacy of first-line combination therapy using riociguat with ambrisentan in patients with Pulmonary Arterial Hypertension (PAH). Phase: Phase 4 Details Lead Sponsor: University of CalgaryCollaborator: BayerTreatments: AmbrisentanRiociguat