Pulmonary Hypertension and Chronic Obstructive Pulmonary Disease: When Is It Out of Proportion?

Patients with chronic obstructive pulmonary disease (COPD) often present with mild pulmonary hypertension (PH). This finding has been attributed to hypoxic pulmonary vasoconstriction. However, a small proportion of COPD patients will present with moderate or severe elevations in their pulmonary artery pressure (PAP), and these patients appear to have worsened symptoms and survival when compared to patients with milder elevations in PAP. The diagnosis of PH in COPD may be difficult, due to inaccuracies in the echocardiographic estimates of PAP in these patients. Additionally, many patients with COPD will also have comorbid conditions such as diastolic heart failure, systolic heart failure, or obstructive sleep apnea, which may cause increased pulmonary pressures through other mechanisms. Clinical trials investigating the effect of PH-specific therapy for patients with PH and COPD have been small, with mixed results. A careful evaluation for other causes of PH and hemodynamic evaluation will help guide medical therapy for this group of patients.