Fig. 1

Distribution of mean pulmonary artery pressure (mPAP, mmHg) across the range of FEV₁ (%predicted) in patients with COPD (n = 69). Resting pulmonary hypertension (PH) was present in 46% of patients with moderate airflow obstruction (i.e., FEV₁: 50–79%predicted), 69% of those with severe airflow obstruction (i.e., FEV₁: 30–49%predicted), and in 42% of patients with very severe airflow obstruction (i.e., FEV₁ < 30%predicted). The proportion of patients with COPD who had resting PH did not differ across the range of airflow obstruction severity as determined by FEV₁ (χ² = 3.01, P = 0.22). COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 s