A 32-year-old woman is diagnosed with pulmonary arterial hypertension (WHO Group 1) with mPAP 48 mmHg, PVR 8 WU, cardiac index 2.0 L/min/m², NYHA class III. She tests positive for vasoreactivity (mPAP fall >10 mmHg to <40 mmHg with inhaled NO). What treatment is most appropriate?

• A Bosentan (endothelin receptor antagonist) + sildenafil
• B Prostacyclin analogue (epoprostenol IV)
• C Anticoagulation alone with warfarin
• D High-dose calcium channel blockers (diltiazem or amlodipine) ✓

Explanation

A positive vasoreactivity test (mPAP drop ≥10 mmHg to <40 mmHg with preserved cardiac output) identifies a subset of IPAH patients (~10-15%) who respond to high-dose calcium channel blockers (diltiazem, amlodipine, or nifedipine) with sustained benefit and improved survival. Responders should receive long-term CCB therapy. Patients who are vasoreactive but fail CCB therapy (or are non-responders) should be treated with PAH-specific therapy (ERA, PDE5i, prostacyclins). ERA+sildenafil combination is for non-responders.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.