Pulmonary Arterial Hypertension Management

Initial Therapy and Combination Therapy

• Initial combination therapy with endothelin receptor antagonists (ERAs) and phosphodiesterase-5 inhibitors (PDE5Is) is recommended for treatment-naïve PAH patients with WHO FC II and III symptoms, as suggested by the American Thoracic Society and European Respiratory Society 1, 2, 3
• The European Respiratory Society recommends initial combination therapy with bosentan dosed at 62.5 mg twice daily for 4 weeks, then 125 mg twice daily, and PDE5Is such as sildenafil (20 mg three times daily) and tadalafil (40 mg once daily) 4, 1, 2, 3
• Sequential combination therapy is recommended for patients who fail to respond adequately to monotherapy, with the addition of a third drug class such as inhaled treprostinil, inhaled iloprost, or riociguat improving 6MWD, WHO FC, and delaying clinical worsening in patients on dual therapy 1, 5

Intravenous Prostacyclin Analogs and Advanced Therapy

• Epoprostenol (IV) is recommended as first-line therapy for severe pulmonary arterial hypertension, with treprostinil (IV, SC, inhaled) as an alternative option, according to the European Respiratory Society 4
• High-risk patients (WHO FC IV) may be treated with intravenous prostacyclin analogs (Epoprostenol), as suggested by the European Society of Cardiology, with bosentan as an alternative option with a Class IIa recommendation 6
• Lung transplantation may be considered for patients with inadequate response to maximal medical therapy, as recommended by the International Society for Heart and Lung Transplantation, based on evidence from 2, 3
• Atrial septostomy may be considered for refractory patients, according to the American College of Cardiology and European Heart Association 3, 7

Contraindications and Interactions

• The European Respiratory Society advises against concomitant use of PDE5Is (sildenafil/tadalafil) and nitrates due to the risk of profound hypotension 4
• Bosentan and cyclosporine are contraindicated due to a 4-fold increase in bosentan levels, and bosentan and glibenclamide are contraindicated due to increased aminotransferases 4
• Hormonal contraceptives may be unreliable in patients taking bosentan due to drug interactions, and warfarin dose adjustments may be necessary when co-administered with bosentan due to increased metabolism 4
• The combination of bosentan and sildenafil results in a 50% decrease in sildenafil levels and a 50% increase in bosentan levels 4

Special Considerations and Lifestyle Modifications

• The American College of Chest Physicians recommends avoiding pregnancy due to a high mortality risk of 30-50% and avoiding high altitude exposure to prevent clinical worsening 1
• Supplemental oxygen should be used during air travel to maintain oxygen saturations above 91% as recommended by the American College of Chest Physicians 1
• Non-essential surgery should be avoided, and when necessary, care should be provided at a pulmonary hypertension center with a multidisciplinary approach including a pulmonary hypertension team, surgical service, and cardiovascular anesthesiology, and careful monitoring of clinical status, oxygenation, and hemodynamics postoperatively as recommended by the American College of Chest Physicians 1
• Lifestyle modifications, including appropriate diet, exercise, and avoidance of pregnancy, are recommended by the American College of Cardiology, along with immunization against influenza and pneumococcal infection, as recommended by the European Respiratory Journal 3, 4

Management and Follow-up

• Regular assessment of treatment response is essential, with adjustments based on clinical status, as recommended by the American Thoracic Society and the American College of Chest Physicians, using risk assessment based on WHO functional class, 6-minute walk distance, right ventricular function, and BNP/NT-proBNP levels, with the following risk category classification:

• The American College of Chest Physicians recommends that PAH patients be managed at centers with expertise in PAH diagnosis and treatment, with requirements for a specialized PH center including: