TABLE 2

Clinical classification of pulmonary hypertension

GroupDescriptionConsiderations
1Pulmonary arterial hypertensionIdiopathic; associated with genetic conditions, drugs and toxins, connective tissue disease, human immunodeficiency virus infection, portal pulmonary hypertension, schistosomiasis, and congenital heart disease; pulmonary arterial hypertension with features of venous or capillary involvement; persistent pulmonary arterial hypertension of the newborn
2Pulmonary hypertension secondary to left heart diseaseAssociated with heart failure with preserved or reduced ejection fraction, valvular heart diseases, or cardiovascular conditions leading to postcapillary pulmonary hypertension
3Pulmonary hypertension secondary to lung diseaseAssociated with chronic obstructive pulmonary disease, emphysema, or both; interstitial lung disease; combined pulmonary fibrosis and emphysema; other parenchymal lung diseases; nonparenchymal restrictive diseases; hypoxia without lung disease; developmental lung diseases
4Pulmonary hypertension associated with pulmonary artery obstructionRelated to chronic thromboembolic disease and other pulmonary artery obstructions
5Pulmonary hypertension with unclear or multifactorial mechanismsRelated to hematologic disorders, systemic disorders (sarcoidosis, pulmonary Langerhans cell histiocytosis and neurofibromatosis type 1), metabolic disorders, chronic renal failure with or without hemodialysis, pulmonary tumor thrombotic microangiopathy, fibrosing mediastinitis, complex congenital heart disease
  • Based on information from reference 3.