Background: Pulmonary hypertension (PH) is associated with a poor prognosis in idiopathic pulmonary fibrosis (IPF). Endothelin-1 (ET-1) and vascular endothelial growth factor (VEGF) are important in both fibrosis and vascular remodeling. Objectives: We sought to determine the relationship between ET-1 and VEGF levels and hemodynamics in patients with IPF. We hypothesized that higher levels of ET-1 and VEGF would be associated with higher pulmonary artery pressures (PAP) and pulmonary vascular resistance (PVR) in patients with IPF. Methods: We performed a cross-sectional analysis of 52 adults with IPF enrolled in a prospective cohort with available clinical data, platelet-free plasma, and hemodynamics. ET-1 and VEGF levels were measured via immunoassay. The associations of ET-1 and VEGF with PAP and PVR were examined using generalized additive models adjusted for age, gender, race/ethnicity, and forced vital capacity (% predicted). Results: Sixteen of 52 (30.8%) had PH (mean PAP ≥25 mm Hg). After multivariable adjustment, higher ET-1 levels were significantly associated with higher systolic (p = 0.01), diastolic (p = 0.02), and mean (p = 0.01) PAP and possibly higher PVR (p = 0.09). There were no significant associations between VEGF levels and hemodynamics. Conclusions: Higher levels of ET-1 were associated with higher PAP and possibly higher PVR in participants with IPF. In a subgroup of patients, ET-1 may be a contributor to pulmonary vascular disease burden in IPF.

Background: Pulmonary hypertension (PH) is associated with a poor prognosis in idiopathic pulmonary fibrosis (IPF). Endothelin-1 (ET-1) and vascular endothelial growth factor (VEGF) are important in both fibrosis and vascular remodeling. Objectives: We sought to determine the relationship between ET-1 and VEGF levels and hemodynamics in patients with IPF. We hypothesized that higher levels of ET-1 and VEGF would be associated with higher pulmonary artery pressures (PAP) and pulmonary vascular resistance (PVR) in patients with IPF. Methods: We performed a cross-sectional analysis of 52 adults with IPF enrolled in a prospective cohort with available clinical data, platelet-free plasma, and hemodynamics. ET-1 and VEGF levels were measured via immunoassay. The associations of ET-1 and VEGF with PAP and PVR were examined using generalized additive models adjusted for age, gender, race/ethnicity, and forced vital capacity (% predicted). Results: Sixteen of 52 (30.8%) had PH (mean PAP ≥25 mm Hg). After multivariable adjustment, higher ET-1 levels were significantly associated with higher systolic (p = 0.01), diastolic (p = 0.02), and mean (p = 0.01) PAP and possibly higher PVR (p = 0.09). There were no significant associations between VEGF levels and hemodynamics. Conclusions: Higher levels of ET-1 were associated with higher PAP and possibly higher PVR in participants with IPF. In a subgroup of patients, ET-1 may be a contributor to pulmonary vascular disease burden in IPF.