Table 1. Updated clinical classification of pulmonary hypertension (PH) (adapted from 6th WSPH document).
| PAH |
| Idiopathic PAH |
| Heritable PAH |
| Drug- and toxin-induced PAH (Table 2) |
| PAH associated with |
| Connective tissue disease |
| HIV infection |
| Portal hypertension |
| Congenital heart disease |
| Schistosomiasis |
| PAH long-term responders to calcium channel blockers |
| PAH with overt features of venous/capillaries (PVOD/PCH) involvement |
| Persistent PH of the newborn syndrome |
| PH due to left heart disease |
| PH due to heart failure with preserved LVEF |
| PH due to heart failure with reduced LVEF |
| Valvular heart disease |
| Congenital/acquired cardiovascular conditions leading to post-capillary PH |
| PH due to lung diseases and/or hypoxia |
| Obstructive lung disease |
| Restrictive lung disease |
| Other lung disease with mixed restrictive/obstructive pattern |
| Hypoxia without lung disease |
| Developmental lung disorders |
| PH due to pulmonary artery obstructions |
| Chronic thromboembolic PH |
| Other pulmonary artery obstructions |
| Sarcoma (high or intermediate grade) or angiosarcoma |
| Other malignant tumours |
| Renal carcinoma |
| Uterine carcinoma |
| Germ cell tumours of the testis |
| Other tumours |
| Non-malignant tumours: uterine leiomyoma |
| Arteritis without connective tissue disease |
| Congenital pulmonary artery stenoses |
| Parasites |
| PH with unclear and/or multifactorial mechanisms |
| Haematological disorders: chronic haemolytic anaemia myeloproliferative disorders |
| Systemic and metabolic disorders: pulmonary Langerhans cell histiocytosis, Gaucher disease, glycogen storage disease, neurofibromatosis, sarcoidosis |
| Others: chronic renal failure with or without hemodialysis, fibrosing mediastinitis |
| Complex congenital heart disease |
| Segmental pulmonary hypertension: isolated pulmonary artery of ductal origin, absent pulmonary artery, pulmonary atresia with ventricular septal defect and major aorto-pulmonary collateral arteries, hemitruncus, other |
| Single ventricle: unoperated, operated |
| Scimitar syndrome |
PAH, pulmonary arterial hypertension; PVOD, pulmonary veno-occlusive disease; PCH, pulmonary capillary haemangiomatosis; LVEF, left ventricular ejection fraction.