Table 1.

Classification of PH (adapted from Galie et al., Eur Heart J 2015)

Classification of PH
Group 1: Pulmonary Arterial Hypertension (PAH)
Idiopathic PAH
Heritable PAH due to known (e.g., BMPR2) or other mutations
Drug and toxin induced
PAH associated with systemic disease
Connective tissue disease
HIV
Portal hypertension (liver disease)
Congenital heart disease
Schistosomiasis
Group 1′: Pulmonary veno-occlusive disease Pulmonary capillary hemangiomatosis
Idiopathic
Heritable (EIF2AK4 or other mutations)
Drugs, toxins and radiation-induced
Associated with connective tissue disease or HIV infection
Group 1′′: Persistent PH of the newborn
Group 2: PH due to left heart disease
Left ventricular systolic or diastolic dysfunction
Valvular disease
Congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathies
Congenital/acquired pulmonary vein stenosis
Group 3: PH due to lung diseases and/or hypoxia
PH due to chronic hypoxia (COPD, interstitial lung disease)
PH due to sleep-disordered breathing
Alveolar hypoventilation disorders
Chronic high altitude exposure
Developmental lung disease
Group 4: PH due to chronic thromboembolic disease and other pulmonary artery obstructions
Chronic thromboembolic pulmonary hypertension
Other pulmonary artery obstructions (e.g., Angiosarcoma, arteritis, parasites)
Group 5: PH due to unclear mechanism
Hematologic disorders (e.g., chronic hemolytic anemia)
Systemic disorders (e.g., sarcoidosis, LAM)
Metabolic disorders (e.g., glycogen storage disease)
Other (e.g., tumoral thrombotic microangiopathy, fibrosing mediastinitis. Chronic renal failure, segmental PH)