Influence of pulmonary hypertension on patients with idiopathic pulmonary fibrosis awaiting lung transplantation

Abstract

Background The influence of varying levels of pulmonary hypertension (PH) on survival in idiopathic pulmonary fibrosis is not well defined. Methods The United Network for Organ Sharing database was queried from 2005 to 2013 to identify first-time lung transplant candidates listed for lung transplantation who were tracked from waitlist entry date until death or censoring to determine the influence of PH on patients with advanced lung disease. Using data for right heart catheterization measurements, mild PH was defined as mean pulmonary artery pressure of 25 mm Hg or more, and severe as 35 mm Hg or more. Results Of 6,657 idiopathic pulmonary fibrosis patients, 6,651 were used for univariate analysis, 6,126 for Kaplan-Meier survival function, 6,013 for multivariate Cox models, and 5,186 (mild PH) and 2,014 (severe PH) for propensity score matching, respectively. Univariate Cox proportional hazards analysis found significant differences in survival for mild PH (hazard ratio [HR] 1.689, 95% confidence interval [CI]: 1.434 to 1.988, p < 0.001) and severe PH (HR 2.068, 95% CI: 1.715 to 2.493, p < 0.001). Further assessment by multivariate Cox models identified significant risk for death for mild PH (HR 1.433, 95% CI: 1.203 to 1.706, p < 0.001) and severe PH (HR 1.597, 95% CI: 1.308 to 1.949, p < 0.001). Propensity score matching confirmed the risk for death for mild PH (HR 1.530, 95% CI: 1.189 to 1.969, p = 0.001) and severe PH (HR 2.103, 95% CI: 1.436 to 3.078, p < 0.001). Conclusions The manifestation of PH, even with mild severity, is associated with significantly increased risk for death among patients with idiopathic pulmonary fibrosis awaiting lung transplantation, so referral should be considered early in the disease course.