Pulmonary arterial hypertension (PAH) is a severe, progressive and potentially fatal disease that impairs the pulmonary circulation and leads to right ventricular failure. One of the world most prevalent etiologies of PAH is schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH). New drugs have emerged to treat other forms of PAH, but their benefits cannot be automatically translated for Sch-PAH patients, since this etiology was not included in the pivotal PAH trials. One of the most promising therapies for the treatment of PAH to emerge in recent years is selexipag, an oral IP receptor agonist, which acts on the prostacyclin pathway. The present study aims to evaluate the efficacy, safety and tolerability of selexipague 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