Selexipag for the Treatment of Schistosomiasis-Associated Pulmonary Arterial Hypertension

Inclusion Criteria: * Patients with symptomatic Sch-PAH. Sch-PAH diagnosis necessarily include the three criteria below 1. Invasive confirmation of PAH, according to the criteria defined in the Pulmonary Hypertension Sixth World Symposium: mean pulmonary artery pressure higher than 20 mmHg, at rest, and the presence of pulmonary vascular resistance (PVR) equal to or greater than 3 W, and a pulmonary capillary pressure considered normal (equal to or lower than 15 mmHg (1)). 2. At least one epidemiological criteria for chronic schistosomiasis: patient from a highly prevalent region for schistosomiasis or previous history of parasitic treatment for schistosomiasis or the presence of Schistosoma mansoni eggs in the patient's feces 3. Evidence of long-term hepatosplenic involvement by schistosomiasis, via compatible ultrasound findings (peri-portal fibrosis or enlarged left lobe) All patients will necessarily already be receiving at least one specific treatment for PAH, either with phosphodiesterase V inhibitor or with an endothelin receptor antagonist, with a stable dose for at least 12 weeks before inclusion in the study. Exclusion Criteria: * Patient without clinical condition to perform the 6-minute walk test * Patient with gastro-intestinal bleeding for over 12 weeks