Which group of pulmonary hypertension includes COPD and interstitial lung disease?

• A. Group 3
• B. Group 1
• C. Group 2
• D. Group 4

Answer: (A)

Group 3 is characterized by pulmonary hypertension due to lung diseases and/or hypoxia. COPD and interstitial lung disease cause chronic damage to the lung parenchyma and persistent low oxygen levels, which trigger vasoconstriction of the pulmonary vessels and eventual vascular remodeling. This pathophysiology raises pulmonary arterial pressures in the setting of underlying lung disease, distinguishing Group 3 from other groups: Group 1 is primarily vascular disease of the pulmonary arteries without significant parenchymal lung disease, Group 2 is PH from left heart disease, and Group 4 is chronic thromboembolic PH. So COPD and ILD fit squarely into Group 3.