What is the standard workup for a patient with suspected pulmonary hypertension and an estimated right ventricular systolic pressure (RVSP) of 50 mmHg?

Standard Workup for Suspected Pulmonary Hypertension with RVSP 50 mmHg

An RVSP of 50 mmHg warrants comprehensive evaluation with echocardiography as the first-line diagnostic test, followed by right heart catheterization to confirm the diagnosis before initiating any PAH-specific therapy. 1

Initial Non-Invasive Diagnostic Workup

Echocardiography (Already Performed)

Your patient already has an RVSP of 50 mmHg, which places them in the intermediate-to-high probability category for pulmonary hypertension. 2 The complete echocardiographic assessment should include: 1

• Right atrial and right ventricular size (RA area, with >18 cm² indicating worse prognosis) 1
• Tricuspid annular plane systolic excursion (TAPSE) (normal >2.0 cm; <1.6 cm warrants further evaluation) 1, 2
• RV fractional area change 1
• Presence and severity of pericardial effusion (indicates worse prognosis) 1
• Left ventricular eccentricity index (assesses septal flattening) 1
• Magnitude of tricuspid regurgitation 1

Mandatory Laboratory Testing

All patients require comprehensive blood work to identify associated conditions: 1

• Complete blood count and coagulation studies (INR if on anticoagulation) 1
• Comprehensive metabolic panel (sodium, potassium, creatinine, liver enzymes including ASAT/ALAT) 1
• BNP or NT-proBNP (BNP >50 ng/L or NT-proBNP >300 ng/L indicates intermediate risk; >300 ng/L or >1400 ng/L respectively indicates high risk) 1
• Thyroid function tests 1
• HIV testing 1, 3
• Immunology panel (ANA, anti-centromere, anti-Scl-70 for connective tissue disease screening) 1
• Uric acid and troponin 1

Pulmonary Function Testing

Lung function tests with DLCO are mandatory to identify underlying lung disease as a cause of pulmonary hypertension (Group 3 PH). 1

Imaging Studies

Ventilation/perfusion (V/Q) scan is the critical next step to exclude chronic thromboembolic pulmonary hypertension (CTEPH), which is potentially curable with surgery. 1 This is a Class I, Level C recommendation and should never be skipped. 1

High-resolution CT of the chest should be considered in all patients to evaluate for interstitial lung disease or other parenchymal abnormalities. 1

Contrast CT angiography is recommended if CTEPH is suspected based on V/Q scan results. 1

Functional Assessment

6-minute walk test (6MWT) with Borg dyspnea score provides prognostic information: 1

• Distance >440 m indicates low risk (<5% 1-year mortality) 1
• Distance 165-440 m indicates intermediate risk (5-10% 1-year mortality) 1
• Distance <165 m indicates high risk (>10% 1-year mortality) 1

Cardiopulmonary exercise testing (CPET) can be performed as an alternative or addition, with peak VO₂ >15 mL/min/kg indicating better prognosis. 1

Additional Screening Based on Risk Factors

Abdominal ultrasound is recommended to screen for portal hypertension if there is any suspicion of liver disease. 1

Arterial or capillary blood gas analysis provides important prognostic information, particularly PaCO₂ levels. 1

Right Heart Catheterization - The Definitive Test

Right heart catheterization is mandatory before initiating any PAH-specific therapy and is necessary to: 1, 4

• Confirm the diagnosis (mean pulmonary artery pressure >20 mmHg defines PH) 5
• Distinguish pre-capillary from post-capillary PH using pulmonary artery wedge pressure (PAWP ≤15 mmHg for pre-capillary) 5
• Calculate pulmonary vascular resistance (PVR >2 Wood Units defines pre-capillary PH) 5
• Measure cardiac index and mixed venous oxygen saturation (CI <2.0 L/min/m² and SvO₂ <60% indicate high risk) 1
• Assess right atrial pressure (RAP >14 mmHg indicates high risk) 1

This is non-negotiable: Echocardiography alone cannot confirm PAH diagnosis or guide treatment decisions. 2, 6 Studies show marked discordance between echo-derived RVSP and catheterization results. 6

Critical Pitfalls to Avoid

Never initiate PAH-specific therapies without hemodynamic confirmation via right heart catheterization, as these medications are contraindicated in Group 2 (left heart disease) pulmonary hypertension. 4

Do not skip the V/Q scan - CTEPH is potentially curable with pulmonary endarterectomy, and missing this diagnosis denies patients definitive treatment. 1

Severe tricuspid regurgitation can significantly underestimate TRV, and cannot be used to exclude PH. 2 If the TR signal is weak, enhance with agitated saline or microbubble contrast. 2

Do not rely on RVSP alone - comprehensive assessment requires evaluation of RV function, chamber sizes, and other echo parameters. 2

Timing and Referral

Patients with RVSP >40-45 mmHg and unexplained dyspnea require referral to a pulmonary hypertension center for comprehensive evaluation. 2 With an RVSP of 50 mmHg, this patient meets criteria for specialist referral and should undergo the complete diagnostic algorithm outlined above before treatment decisions are made. 1, 2