Group III Pulmonary Hypertension: Pulmonary Hypertension Associated with Lung Disease: Epidemiology, Pathophysiology, and Treatments.

Pulmonary hypertension (PH) associated with chronic lung disease (WHO group 3) is the second leading cause of PH and is associated with increased morbidity and mortality. Elevation of pulmonary arterial pressure (PAP) is usually moderate and correlates with severity of lung disease. In a small minority, PAP may approach that seen in WHO group 1 pulmonary arterial hypertension (PAH). Current medications for treating PAH have not shown benefit in controlled trials of group 3 PH and their routine use is discouraged. Patients with severe group 3 PH should be considered for referral to expert centers or entry into clinical trials.