Diagnostic Approach to Suspected Severe Pulmonary Hypertension

Immediate Diagnostic Workup

• The American College of Cardiology recommends that an RVSP >40 mmHg warrants further evaluation in patients with unexplained dyspnea, and severe elevation (≥60 mmHg or tricuspid regurgitation velocity >3.4 m/s) indicates high probability of PH requiring RHC 4, 1.
• The European Respiratory Society suggests that RHC is the gold standard and mandatory for confirming PH diagnosis before initiating any PAH-specific therapy 1, 2.
• Echocardiography may underestimate pulmonary artery pressure by a mean of 11 mmHg, with underestimation of ≥20 mmHg in up to 31% of patients, according to the European Respiratory Journal 5.

Comprehensive Evaluation Before RHC

• The American College of Cardiology recommends completing the following tests to identify underlying etiology and assess disease severity: complete blood count, comprehensive metabolic panel, liver function tests, thyroid function testing, N-terminal pro-BNP (NT-proBNP) for prognostic assessment, HIV serology, antinuclear antibody (ANA), hepatitis serologies, and hypercoagulable panel if clinically indicated 4, 6.
• The European Respiratory Society suggests that ventilation/perfusion (V/Q) scan is the preferred screening method for chronic thromboembolic pulmonary hypertension (CTEPH) due to higher sensitivity 2, 3.

Right Heart Catheterization Protocol

• The European Respiratory Society recommends that RHC provides definitive hemodynamic diagnosis and guides treatment decisions, with a mean pulmonary artery pressure >20 mmHg confirming PH 7, 3.
• The American College of Cardiology suggests that distinguishing PAH from other PH types requires pulmonary artery wedge pressure ≤15 mmHg and pulmonary vascular resistance ≥3 Wood units for PAH diagnosis 7, 3.

Risk Stratification and Prognosis

• The American College of Cardiology recommends that elevated RVSP correlates with poor outcomes, with mortality risk increasing approximately 40% for every 10 mmHg increase in pulmonary artery systolic pressure 3.
• The European Respiratory Society suggests that right ventricular function is a critical determinant of outcomes and should be carefully assessed during diagnostic workup 3.

Specialist Referral

• The American College of Cardiology recommends referring to a pulmonary hypertension specialist immediately for patients with confirmed severe PH on echocardiography, as management requires expertise in hemodynamic assessment, vasoreactivity testing, and PAH-specific therapies 7, 6, 3.