Pulmonary hypertension — viva

Stem

Practice viva. The examiner starts with a breathless patient whose echocardiogram suggests pulmonary hypertension, and works through the definitions and groups, the diagnostic pathway, PAH treatment by risk, the left heart and lung disease traps, CTEPH, pregnancy, and where the European, US and ANZ sources differ.

Branch A — Definitions and groups

Examiner: Define pulmonary hypertension, and tell me how you split pre- from post-capillary disease.^[1]

Strong answer:

• ESC/ERS 2022 defines PH as an mPAP above 20 mmHg at rest, based on haemodynamic assessment by RHC.^[1]
• Pre-capillary PH adds a PAWP of 15 mmHg or less and a PVR above 2 WU; post-capillary PH has a PAWP above 15 mmHg, split by PVR into IpcPH (2 WU or less) and CpcPH (above 2 WU).^[1]
• The guideline puts both the upper limit of normal PVR and the lowest prognostically relevant PVR at about 2 WU.^[1]
• The five groups are PAH; PH with left heart disease; PH with lung diseases and/or hypoxia; PH with pulmonary artery obstructions; and PH with unclear and/or multifactorial mechanisms (Table 6).^[1]

Examiner: Does a patient with mPAP 22 mmHg and PVR 2.5 WU benefit from PAH drugs?^[1]

Strong answer: PAH may now be diagnosed in that range, but ESC/ERS 2022 says drug efficacy has only been shown with mPAP of 25 mmHg or more and PVR above 3 WU, and no data are available below those values.^[1]

Branch B — Diagnosis

Examiner: The echocardiogram shows a peak TRV of 3.1 m/s. Does she have PH?^[1]

Strong answer:

• Not yet: echocardiography alone is insufficient to confirm PH, which requires RHC.^[1]
• A peak TRV above 2.8 m/s may suggest PH, but TRV alone cannot reliably determine whether PH is present; the guideline assigns a probability using TRV with the Table 10 signs, and signs from at least two categories must be present to alter it.^[1][2]
• Referral to a PH centre is advised with an intermediate/high probability of PH, risk factors for PAH, or a history of PE, and the PH centre performs an invasive assessment according to the clinical scenario.^[1]
• A V/Q or perfusion lung scan is recommended in unexplained PH to assess for CTEPH (ESC/ERS 2022, Class I, Level C).^[2]

Examiner: Who gets vasoreactivity testing, and what counts as a positive test?^[2]

Strong answer: ESC/ERS 2022 recommends it in idiopathic, heritable or drug-associated PAH to find patients who can be treated with high doses of a CCB (Class I, Level B). A positive response is a fall in mPAP of 10 mmHg or more to 40 mmHg or less, with an increased or unchanged cardiac output (ESC/ERS 2022, Class I, Level C). Fewer than 10% of these patients are responders.^[2][1]

Branch C — Treating PAH

Examiner: A non-vasoreactive man with idiopathic PAH, no cardiopulmonary comorbidities and intermediate risk at diagnosis. What do you start?^[2]

Strong answer:

• ESC/ERS 2022: initial combination therapy with a PDE5i and an ERA is recommended at low or intermediate risk (Class I, Level B; GRADE: low quality, conditional); ambrisentan with tadalafil, or macitentan with tadalafil, are both Class I, Level B.^[2]
• AMBITION supports it: in this event-driven, double-blind trial, treatment-naive participants with WHO-FC II or III PAH were randomised 2:1:1; in the primary analysis of 500 participants, a first clinical-failure event (the primary end point) occurred in 18% with ambrisentan plus tadalafil, against 34% and 28% with ambrisentan or tadalafil monotherapy.^[5]
• At high risk, initial combination therapy with a PDE5i, an ERA and i.v./s.c. prostacyclin analogues should be considered (ESC/ERS 2022, Class IIa, Level C).^[2]
• With cardiopulmonary comorbidities, initial monotherapy with a PDE5i or an ERA should be considered instead (ESC/ERS 2022, Class IIa, Level C).^[2]

Examiner: At review he is at intermediate–low risk on an ERA and a PDE5i. What next?^[2]

Strong answer:

• ESC/ERS 2022: at intermediate–low risk on ERA/PDE5i therapy, addition of selexipag should be considered (Class IIa, Level B), and switching from PDE5i to riociguat may be considered (Class IIb, Level B).^[2]
• The 2026 ERS update recommends add-on sotatercept in PAH patients already on PAH drugs at intermediate–low, intermediate–high or high risk of death during follow-up, based on high-certainty evidence from RCTs.^[15]
• Riociguat must not be combined with a PDE5i: the combination is not recommended (ESC/ERS 2022, Class III, Level B) and is contraindicated.^[2][1]

Branch D — Left heart and lung disease

Examiner: A patient with HFpEF has isolated post-capillary PH at catheterisation (mPAP >20 mmHg, PAWP >15 mmHg, PVR ≤2 WU). Would you give a PAH drug?^[2][1]

Strong answer: No. Drugs approved for PAH are not recommended in PH-LHD (ESC/ERS 2022, Class III, Level A), and PDE5is in HFpEF with isolated post-capillary PH are not recommended (ESC/ERS 2022, Class III, Level C; GRADE: low quality, conditional).^[2]

Examiner: And in lung disease?^[1]

Strong answer: ESC/ERS 2022 calls PH in lung disease severe when PVR is above 5 WU. PAH medication is not recommended with non-severe PH (ESC/ERS 2022, Class III, Level C), but inhaled treprostinil may be considered in PH associated with ILD (Class IIb, Level B), irrespective of severity.^[1][2]

Branch E — CTEPH

Examiner: How do you treat CTEPH?^[1]

Strong answer:

• ESC/ERS 2022: review of all patients with CTEPH by a CTEPH team for the assessment of multi-modality management is recommended (Class I, Level C), and lifelong, therapeutic doses of anticoagulation are recommended in all patients with CTEPH (Class I, Level C).^[2]
• ESC/ERS 2022 combines PEA, BPA and medical therapy to target proximal lesions, distal lesions and microvasculopathy respectively.^[1]
• ESC/ERS 2022: PEA is the treatment of choice when fibrotic obstructions are accessible by surgery (Class I, Level B); BPA is recommended when technically inoperable or with residual PH after PEA and distal obstructions amenable to BPA (Class I, Level B); riociguat is recommended for symptomatic inoperable CTEPH or persistent/recurrent PH after PEA (Class I, Level B).^[2]
• CHEST-1, a phase 3, multicentre, double-blind, placebo-controlled trial, randomised 261 patients with inoperable CTEPH or persistent or recurrent PH after PEA; by week 16 the 6MWD rose by a mean of 39 m with riociguat and fell by 6 m with placebo.^[6]

Branch F — Pregnancy and regional sources

Examiner: A woman with PAH asks about pregnancy. What does the current ESC guidance say?^[3]

Strong answer: The 2025 ESC pregnancy guideline recommends multidisciplinary-team counselling for women of childbearing potential with PAH who wish to become pregnant, about the very high risk of pregnancy-related adverse events and with shared decision-making on whether to become pregnant (Class I, Level C). It also recommends clear contraceptive advice for women of childbearing potential with PAH (ESC 2025, Class I, Level C). ERAs, riociguat and selexipag are not recommended during pregnancy (ESC 2025, Class III, Level C).^[3]

Examiner: What would you tell an Australian or US examiner about local sources?^[12][4]

Strong answer: No ACC/AHA or Australian and New Zealand PH guideline was found in the census for this topic. The 2026 AHA/ACC PE guideline recommends a diagnostic evaluation for CTEPD with ongoing dyspnoea and/or functional impairment after 3 months or more of therapeutic anticoagulation after acute PE (COR 1, LOE B-NR).^[4] Among patients diagnosed with CTEPH in the PHSANZ registry (January 2004 to March 2020), 146 of 386 (37.8%) had PEA, which the authors call only a minority and significantly less than overseas reports.^[12]