What is the workup for severe pulmonary arterial hypertension (PAH)?

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Last updated: April 24, 2025 • View editorial policy

From the Guidelines

The workup for severe pulmonary hypertension should begin with a comprehensive clinical evaluation, including a detailed history and physical examination, followed by specific diagnostic tests to confirm the diagnosis and determine its etiology, as recommended by the most recent guidelines 1. The initial testing should include an electrocardiogram to assess for right heart strain, chest X-ray to evaluate for underlying lung disease, pulmonary function tests to identify respiratory disorders, and echocardiography to estimate pulmonary artery pressure and assess right ventricular function.

  • Right heart catheterization is essential for definitive diagnosis, measuring mean pulmonary artery pressure (mPAP ≥25 mmHg at rest confirms pulmonary hypertension), pulmonary capillary wedge pressure, cardiac output, and calculating pulmonary vascular resistance, as stated in the guidelines 2.
  • Additional testing should include ventilation-perfusion scanning to rule out chronic thromboembolic pulmonary hypertension, high-resolution CT scanning of the chest to identify interstitial lung disease or emphysema, sleep studies to evaluate for sleep-disordered breathing, laboratory tests including HIV testing, liver function tests, autoimmune markers, and BNP/NT-proBNP levels.
  • A 6-minute walk test should be performed to assess functional capacity and serve as a baseline for treatment response, as suggested by the expert panel report 3. This comprehensive approach allows for classification of pulmonary hypertension into one of five groups (WHO classification), which guides specific treatment strategies targeting the underlying cause while managing symptoms and preventing right heart failure, in accordance with the updated clinical classification of PH 2.

From the Research

Work-up for Severe Pulmonary Hypertension

  • The work-up for severe pulmonary hypertension involves a multidimensional approach, including exercise capacity, cardiopulmonary hemodynamics, and functional class assessment 4
  • Endothelin receptor antagonists, such as bosentan, have been shown to improve exercise capacity and hemodynamics in patients with pulmonary hypertension 5, 6, 7, 8
  • The use of bosentan has been demonstrated to reduce pulmonary vascular resistance and improve cardiac index in patients with severe pulmonary hypertension 5, 7

Treatment Options

  • Current guidelines recommend the use of two oral medications, including an endothelin receptor antagonist and a phosphodiesterase type-5 inhibitor, for low- and intermediate-risk patients with pulmonary arterial hypertension 4
  • Combination therapy, including a parenteral prostacyclin, may be considered for high- or intermediate-high risk patients 4
  • Bosentan has been shown to be effective in improving exercise capacity and reducing symptoms in patients with pulmonary hypertension, and may be used as part of combination therapy 6, 8

Monitoring and Safety

  • Patients treated with bosentan require regular monitoring of liver enzymes, as the drug may cause hepatotoxicity 6, 8
  • The safety and tolerability of bosentan have been demonstrated in long-term studies, with the majority of patients experiencing no significant adverse effects 7, 8

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.