When to Initiate a Workup for Pulmonary Hypertension
A workup for pulmonary hypertension is indicated when echocardiography shows "PH likely" with symptoms, regardless of risk factors, or when echocardiography shows "PH possible" with symptoms and risk factors for pulmonary arterial hypertension. 1
Echocardiographic-Based Indications
- Right heart catheterization (RHC) is recommended when echocardiography shows "PH likely" with symptoms, regardless of risk factors 1
- RHC should be considered when echocardiography shows "PH likely" without symptoms, regardless of risk factors 1
- RHC should be considered when echocardiography shows "PH possible" with symptoms and risk factors for pulmonary arterial hypertension (PAH) 1
- Alternative diagnosis evaluation and echocardiographic follow-up are recommended when echocardiography shows "PH possible" with symptoms but no risk factors; RHC may be considered if symptoms are at least moderate 1
- Echocardiographic follow-up is recommended when echocardiography shows "PH possible" without symptoms and without risk factors 1
- No additional workup is needed when echocardiography shows "PH unlikely" and the patient has no symptoms 1
Symptom-Based Indications
- Unexplained syncope warrants a pulmonary hypertension workup 1, 2
- Progression from WHO Functional Class I to higher classes necessitates evaluation 1, 3
- Unexplained dyspnea on exertion, especially when progressive, should prompt consideration of PH 2
- Signs of right ventricular dysfunction without clear cause require investigation 2
- Patients with WHO Functional Class III-IV symptoms have more severe disease and require prompt evaluation 4, 3
Risk Factor-Based Indications
- Echocardiographic follow-up is recommended when echocardiography shows "PH unlikely" but the patient has symptoms AND risk factors for PAH 1
- Patients with connective tissue diseases (particularly systemic sclerosis) should be screened regularly 5
- Individuals with a family history of PAH should be considered for screening due to potential genetic predisposition (BMPR2, ACVRL1, ENG, or Smad8 mutations) 5
- Patients with congenital heart disease, particularly those with systemic-to-pulmonary shunts, require evaluation 6
- History of exposure to drugs associated with PAH (such as mitomycin-C, carfilzomib, or anorexigens) warrants investigation 7
Components of the Diagnostic Workup
- Ventilation/perfusion lung scan is essential in all patients with unexplained PH to exclude chronic thromboembolic PH (CTEPH) 1, 7
- Contrast CT angiography is recommended for patients with suspected CTEPH 1
- Laboratory testing should include routine biochemistry, hematology, immunology, and thyroid function tests to identify associated conditions 1
- Abdominal ultrasound is recommended for screening of portal hypertension 1
- High-resolution CT should be considered in all PH patients 1
- Right heart catheterization is the gold standard for definitive diagnosis, confirming PH when mean pulmonary arterial pressure is >20 mmHg 7
Clinical Pearls and Pitfalls
- Do not rely solely on echocardiography for diagnosis; RHC is essential for accurate diagnosis and classification 8, 7
- Avoid open or thoracoscopic lung biopsy in patients with suspected PAH 1
- Remember that PH can be a manifestation of various underlying conditions, including left heart disease and chronic lung disease, which are common causes in clinical practice 8
- The WHO Functional Classification is a critical tool for assessing disease severity and monitoring progression 3
- Early referral to a pulmonary hypertension specialist center is crucial for optimal management, especially for patients with PAH or CTEPH 8, 2
By following these evidence-based guidelines for when to initiate a workup for pulmonary hypertension, clinicians can ensure timely diagnosis and appropriate management of this potentially life-threatening condition.