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Systemic sclerosis-associated pulmonary arterial hypertension — SCE Respiratory MCQ

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HardHypertensionSystemic sclerosis-associated pulmonary arterial hypertensionSCE Respiratory

A 49-year-old woman with limited cutaneous systemic sclerosis is referred to a national pulmonary hypertension centre with progressive exertional dyspnoea. She is in WHO functional class III and has had no syncope. Her 6-minute walk distance is 330 m and NT-proBNP is 780 ng/L. Blood pressure is 118/72 mmHg. She has no obesity, diabetes, systemic hypertension, coronary disease or smoking history. HRCT shows no interstitial lung disease, and FVC is 92% predicted. Right heart catheterisation shows mean pulmonary arterial pressure 47 mmHg, pulmonary arterial wedge pressure 10 mmHg, pulmonary vascular resistance 8.6 Wood units, right atrial pressure 7 mmHg and cardiac index 2.4 L/min/m². At the referring hospital, inhaled nitric oxide reduced mean pulmonary arterial pressure to 36 mmHg without reducing cardiac output. Ventilation–perfusion scintigraphy is normal. Which initial pulmonary arterial hypertension-targeted regimen is most appropriate?

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Correct answer: E — Start ambrisentan plus tadalafil

Explanation lettering: D = shown as B · E = shown as D · B = shown as E

This is haemodynamically confirmed systemic sclerosis-associated pulmonary arterial hypertension: the wedge pressure is normal, PVR is substantially elevated, significant parenchymal lung disease is absent and the normal ventilation–perfusion scan argues against CTEPH. Her functional, exercise, biomarker and haemodynamic findings indicate intermediate rather than high baseline risk. Although the nitric oxide response fulfils the numerical definition of acute vasoreactivity, high-dose calcium-channel blocker treatment is reserved for vasoreactive idiopathic, heritable or drug-associated PAH. Vasoreactivity in connective tissue disease-associated PAH does not reliably predict a durable calcium-channel blocker response; therefore A is inappropriate. For clear-cut, non-high-risk connective tissue disease-associated PAH without a major cardiopulmonary comorbidity phenotype, initial combination treatment with an endothelin-receptor antagonist and a phosphodiesterase-5 inhibitor is recommended. Ambrisentan plus tadalafil is an evidence-supported combination, making B correct. Initial triple therapy incorporating intravenous epoprostenol is principally appropriate for high-risk disease, which is not demonstrated here, so C represents overtreatment. Tadalafil monotherapy may be selected when substantial cardiopulmonary comorbidity or tolerability concerns favour a cautious single-agent approach, neither of which applies; D is therefore inferior. Riociguat monotherapy has less evidence than initial ERA–PDE5 inhibitor combination therapy in this phenotype and is particularly established for selected CTEPH, which has been excluded, making E incorrect.

Reference: 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension (2022 online; European Respiratory Journal 2023) — https://publications.ersnet.org/content/erj/61/1/2200879 Treatment algorithm for pulmonary arterial hypertension (2024) — https://publications.ersnet.org/content/erj/64/4/2401325