Diagnostic Workup for Pulmonary Hypertension

Initial Evaluation

The European Society of Cardiology recommends echocardiography as the first-line non-invasive diagnostic test when pulmonary hypertension is suspected 1
Clinical history, symptoms, signs, ECG, and chest radiograph should be evaluated to identify risk factors and potential causes 2
Laboratory testing should include complete blood count, renal and liver function tests, thyroid function tests, immunology screening, and HIV testing 1
Pulmonary function tests with diffusing capacity of the lung for carbon monoxide are essential in the initial evaluation 1, 3
High-resolution CT of the chest should be considered in all patients with pulmonary hypertension to identify underlying lung disease 1, 2

For high or intermediate probability of pulmonary hypertension on echocardiography, evaluate for left heart disease and lung diseases through clinical assessment, ECG, PFTs with DLCO, chest radiograph, HRCT, and arterial blood gases 2, 4
If left heart or lung disease is confirmed, treat the underlying condition 2
If severe pulmonary hypertension or right ventricular dysfunction is present, refer to a pulmonary hypertension expert center 2
If left heart or lung disease is not confirmed, perform ventilation/perfusion lung scan to exclude chronic thromboembolic pulmonary hypertension 1, 2

Ventilation/perfusion or perfusion lung scan is mandatory in patients with unexplained pulmonary hypertension to exclude chronic thromboembolic pulmonary hypertension 1, 2
If V/Q scan shows multiple segmental perfusion defects, chronic thromboembolic pulmonary hypertension should be suspected 2
Proceed with CT pulmonary angiography, right heart catheterization, and selective pulmonary angiography if V/Q scan is abnormal 1, 2
Abdominal ultrasound is recommended for screening of portal hypertension 1
Additional specialized testing based on clinical suspicion, including extended laboratory testing and genetic testing for BMPR2, ACVRL1, and ENG mutations in cases of suspected heritable pulmonary arterial hypertension 4, 6

Right heart catheterization is required for definitive diagnosis of pulmonary hypertension 3
Diagnostic criteria include mean pulmonary arterial pressure ≥25 mmHg at rest and pulmonary vascular resistance >3 Wood units for pulmonary arterial hypertension 2

Open or thoracoscopic lung biopsy is not recommended in patients with pulmonary arterial hypertension 1
CT pulmonary angiography alone may miss the diagnosis of chronic thromboembolic pulmonary hypertension; V/Q scan is more sensitive 1, 2
Regular follow-up assessments every 3-6 months are recommended in stable patients once diagnosis is established 6, 7

The European Respiratory Society classifies pulmonary hypertension into five groups, including pulmonary arterial hypertension, pulmonary hypertension due to left heart disease, pulmonary hypertension due to lung diseases and/or hypoxia, chronic thromboembolic pulmonary hypertension, and pulmonary hypertension with unclear/multifactorial mechanisms 8