When is a workup for pulmonary hypertension indicated?

When to Initiate a Workup for Pulmonary Hypertension

A workup for pulmonary hypertension is primarily indicated based on echocardiographic findings, presence of symptoms, and risk factors, with right heart catheterization recommended for patients with high probability of pulmonary arterial hypertension. 1

Echocardiographic-Based Indications

The decision to pursue a pulmonary hypertension workup follows a structured approach based on echocardiographic findings:

Low Probability for PAH

• No additional workup is recommended when echocardiography shows "PH unlikely" and the patient has no symptoms 1
• Echocardiographic follow-up is recommended when echocardiography shows "PH unlikely" but the patient has symptoms AND risk factors for PAH 1
• Evaluation of other causes for symptoms is recommended when echocardiography shows "PH unlikely" with symptoms but NO risk factors for PAH 1

Intermediate Probability for PAH

• Echocardiographic follow-up is recommended when echocardiography shows "PH possible" without symptoms and without risk factors 1
• Right heart catheterization (RHC) may be considered when echocardiography shows "PH possible" with symptoms and risk factors 1
• Alternative diagnosis evaluation and echocardiographic follow-up may be considered when echocardiography shows "PH possible" with symptoms but no risk factors; if symptoms are at least moderate, RHC may be considered 1

High Probability for PAH

• Right heart catheterization is recommended when echocardiography shows "PH likely" with symptoms, regardless of risk factors 1
• Right heart catheterization should be considered when echocardiography shows "PH likely" without symptoms, regardless of risk factors 1

Symptom-Based Indications

A workup should be initiated when patients present with:

• Unexplained dyspnea on exertion (most common symptom) 2
• Unexplained syncope 3
• Signs of right ventricular dysfunction 2
• Progression from WHO Functional Class I to higher classes 3

Risk Factor-Based Indications

Patients with the following conditions should be screened for pulmonary hypertension:

• Systemic sclerosis (annual echocardiography recommended) 4
• Other connective tissue diseases (when symptoms develop) 4
• HIV infection 5
• Portal hypertension/chronic liver disease 5
• History of anorexigen use (fenfluramine, amphetamines) 5
• Family history of PAH 6

Components of the Diagnostic Workup

Once indicated, the workup should include:

• Ventilation/perfusion lung scan - recommended in all patients with unexplained PH to exclude chronic thromboembolic PH (CTEPH) 1
• Contrast CT angiography - indicated for patients with suspected CTEPH 1
• Laboratory testing - routine biochemistry, hematology, immunology, and thyroid function tests to identify associated conditions 1
• Abdominal ultrasound - indicated for screening of portal hypertension 1
• High-resolution CT - should be considered in all PH patients 1
• Right heart catheterization - essential for accurate diagnosis and classification 6

Important Considerations

• Patients with suspected or confirmed PH without confirmed left-sided heart or lung diseases should be referred to a specialist center 6
• Open or thoracoscopic lung biopsy is not recommended in patients with PAH 1
• Early diagnosis is critical as targeted treatments are available that can improve morbidity, mortality, and quality of life 6, 5
• The WHO Functional Classification is an important tool for assessing disease severity and monitoring progression 3

Common Pitfalls to Avoid

• Delaying workup in patients with progressive unexplained dyspnea 2
• Failing to perform V/Q scan in patients with suspected PH (may miss treatable CTEPH) 1
• Initiating treatment without confirming diagnosis with right heart catheterization 6
• Not referring patients with PAH or CTEPH to specialist centers 6
• Overlooking screening in high-risk populations, particularly systemic sclerosis patients 4