Transitioning Stable Patients with Pulmonary Arterial Hypertension from Parenteral Prostanoids to Oral Selexipag

Introduction: Parenteral prostanoids are the most potent therapies for pulmonary arterial hypertension (PAH) but are associated with complications and lifestyle limitations. Carefully selected stable patients may be considered for a transition from parenteral prostanoids to a more convenient oral regimen. We present our experience transitioning patients on parenteral prostanoids to selexipag on an outpatient basis. Methods: This was a retrospective cohort study of all group 1 PAH patients on parenteral prostanoids who transitioned to selexipag using a standardized outpatient-based protocol. Hospitalization and routine prognostic data were recorded. Results: Fourteen patients were followed for a median of 1,240 (1,052–1,528) days; all were functional class (FC) II (n = 9) or III (n = 5). Thirteen patients completed the transition, including 11 who underwent catheterization 376 (321–735) days after discontinuing parenteral therapy. Three patients had unfavorable transitions requiring reinitiation of parenteral treatment. Overall, pulmonary vascular resistance increased (3.3–4.5 WU, p = 0.01), cardiac index fell (4.0–2.8 L/min/m², p = 0.01), N-terminal pro-hormone of brain natriuretic peptide worsened (111–205 pg/dL, p = 0.03), but PAH-related hospitalizations improved (27–8, p = 0.02). Cardiac imaging, FC, and 6-min walk distance (6MWD) were unchanged. Patients who failed were older (64 vs. 56 years old) with shorter 6MWD (274 vs. 392 m) and higher REVEAL 2.0 scores (11 vs. 3). Conclusions: Transition from parenteral prostanoids to oral selexipag in carefully selected low-risk patients was well-tolerated in many patients, with up to 5 years of follow-up. Overall, the hemodynamic response to transition is unpredictable and close monitoring, particularly in the first year of follow-up, is recommended. Additional evaluation of potential predictors of success is necessary.