Table 2.

Summary of CHEST/American College of Chest Physicians guidelines for pharmacological treatment of PAH¹⁸

Patient status*	WHO FC II	WHO FC III	WHO FC IV
Treatment naïve	Monotherapy with any approved ERA, PDE5i or riociguat	Monotherapy with any approved ERA, PDE5i or riociguat	Monotherapy with parenteral prostanoid
Treatment naïve, unable or unwilling to receive parenteral prostanoids	–	–	Inhaled prostanoid plus ERA
Treatment naïve with evidence of rapid disease progression or markers of poor prognosis	–	Initial monotherapy with parenteral prostanoid or subcutaneous treprostinil	–
Receiving one or two oral therapies with evidence of rapid disease progression or markers of poor prognosis	–	Addition of parenteral or inhaled prostanoid	–
Receiving ERA or PDE5i but remains symptomatic	–	Addition of inhaled prostanoid	–
Receiving established monotherapy, with unacceptable clinical status	–	▸ Add inhaled prostanoids to stable ERA/PDE5i ▸ Add sildenafil to epoprostenol ▸ Add riociguat to bosentan, ambrisentan or inhaled prostanoid ▸ Add macitentan to PDE5i
Receiving dual combined therapy, with unacceptable clinical status	–	Add a third class of therapy. Patient should ideally be treated at an expert centre

*Pharmacotherapy is not recommended for patients with WHO FC I.

ERA, endothelin receptor antagonist; PAH, pulmonary arterial hypertension; PDE5i, phosphodiesterase 5 inhibitor; WHO FC, WHO functional class.