Background: Guidelines for the treatment of World Health Organization (WHO) functional class (FC) III pulmonary arterial hypertension (PAH) provide for oral (PO) therapy or parenteral prostacyclins at the discretion of expert physicians. The objective of this study was to assess the appropriateness of PO-first treatment in patients with WHO FC III PAH.
Methods: This study was a retrospective analysis of 79 treatment-naive adult patients with idiopathic, familial, or anorexigen-associated PAH, referred to a single pulmonary hypertension center. Forty-eight received either PO therapy with an endothelin receptor antagonist, calcium channel blocker, or phosphodiesterase inhibitor (PO group) and 31 an IV or subcutaneous (SC) prostacyclin (IV/SC group).
Results: Patients in the IV/SC group had a significantly worse baseline hemodynamic profile; however, on univariate analysis, there was no association between hemodynamics and mortality. Initial treatment with PO vs IV/SC therapy was associated with a lower overall mortality (20.8% vs 45.2%, P = .02) and a lower 5-year mortality (14.6% vs 32.3%, P = .062). Based on the National Institutes of Health equation, actual survival for patients who received PO therapy was greater than predicted at 5 years. Finally, there were similar improvements between groups in 6-min walk distance (P = .38) at 6 to 12 months after initiation of treatment.
Conclusions: For WHO FC III PAH that is idiopathic, familial, or anorexigen associated, the clinical decision for treatment with a PO-first strategy is associated with a high survival rate when patients are appropriately risk stratified prior to initiation of therapy. The more potent prostacyclins can be reserved for high-risk patients, those with evidence of disease progression, or those with treatment failure.