Pulmonary Hypertension

The answer first

Pulmonary hypertension is an elevated pressure in the pulmonary circulation, defined by right heart catheterisation as a mean pulmonary artery pressure above 20 mmHg. The 2022 ESC/ERS guidelines lowered the diagnostic threshold from the previous 25 mmHg, in line with the 6th World Symposium haemodynamic definitions, and reintroduced the concept of exercise pulmonary hypertension. The diagnosis is haemodynamic, but management is determined by the clinical classification — the five WHO groups — because the groups have different causes, different treatments, and different prognoses. ^[1]

The four decisions examiners test again and again: ^[1]

1. Which group is this? The single most important step is assigning the WHO group, because PAH-specific therapy (the ERA, PDE5, prostacyclin, sGC, and activin-inhibitor classes) is effective and indicated for Group 1 and Group 4 disease, and is generally harmful or unproven in Groups 2, 3, and 5.
2. Confirm with right heart catheterisation. Echocardiography estimates right ventricular systolic pressure but cannot diagnose pulmonary hypertension. Right heart catheterisation is mandatory — it confirms the diagnosis, defines the haemodynamic phenotype (pre-capillary, post-capillary, or combined), and rules out left heart disease.
3. Risk-stratify and treat to a low-risk target. The ESC/ERS 2022 model uses a three-strata approach (low, intermediate, high) built from functional class, 6-minute walk distance, natriuretic peptides, imaging, and haemodynamics. Treatment is escalated until the patient reaches a low-risk profile.
4. Screen for the underlying cause. A cause is found in most cases — connective tissue disease (especially systemic sclerosis), congenital heart disease, portal hypertension, HIV, drugs (dasatinib, fenfluramine), and schistosomiasis — and V/Q scanning excludes chronic thromboembolic disease, which is potentially curable. ^[1]

DWE high-yield: When a stem describes a young woman with exertional dyspnoea, a loud P2, and a raised estimated RVSP on echo, the next investigation is a full PAH workup culminating in right heart catheterisation. If the question asks for the best test to exclude chronic thromboembolic pulmonary hypertension, the answer is a V/Q scan, not a CTPA. ^[1]

References8ShowHide

1. [1]Humbert M, Kovacs G, Hoeper MM, et al. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension Eur Heart J, 2022.PMID 36017548
2. [2]Simonneau G, Montani D, Celermajer DS, et al. Haemodynamic definitions and updated clinical classification of pulmonary hypertension Eur Respir J, 2019.PMID 30545968
3. [3]Hoeper MM, Badesch DB, Ghofrani HA, et al. Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension N Engl J Med, 2023.PMID 36877098
4. [4]Galiè N, Barberà JA, Frost AE, et al. Initial Use of Ambrisentan plus Tadalafil in Pulmonary Arterial Hypertension N Engl J Med, 2015.PMID 26308684
5. [5]Sitbon O, Channick R, Chin KM, et al. Selexipag for the Treatment of Pulmonary Arterial Hypertension N Engl J Med, 2015.PMID 26699168
6. [6]Pulido T, Adzerikho I, Channick RN, et al. Macitentan and morbidity and mortality in pulmonary arterial hypertension N Engl J Med, 2013.PMID 23984728
7. [7]Ghofrani HA, Galiè N, Grimminger F, et al. Riociguat for the treatment of pulmonary arterial hypertension N Engl J Med, 2013.PMID 23883378
8. [8]Ghofrani HA, D'Armini AM, Grimminger F, et al. Riociguat for the treatment of chronic thromboembolic pulmonary hypertension N Engl J Med, 2013.PMID 23883377