Pulmonary Hypertension in End-Stage Pulmonary Fibrosis: Prevalence, Predictors and Survival before and after Lung Transplantation

Abstract

Purpose The prevalence, prognosis and factors that predict the presence and degree of pulmonary hypertension (PH) in patients with end-stage idiopathic pulmonary fibrosis (IPF) remain unclear. Methods and Materials This retrospective study analyzed the occurrence and degree of PH (mPAP ≥25mmHg and PCWP ≤15mmHg) with right heart catheterization (RHC), in a consecutive cohort of patients with end-stage IPF at Rigshospitalet, Denmark. A total of 100 patients with end-stage IPF were evaluated for lung transplantation and had available RHC data. The analysis excluded 10 patients with PVH (mPAP ≥25 mm Hg, PCWP >15 mmHg). Prediction of PH was assessed using regression analysis and prognosis was determined using Kaplan-Meier statistics. Results The analysis included 90 patients, of whom 44 had PH (21 transplanted), and the remaining 46 patients had normal pulmonary pressures (21 transplanted). The group mPAP showed a skewed distribution towards high mPAPs with a median of 24.5mmHg (range 10-59mmHg). The mean age at evaluation was 53.7±10.2 years (32% women). All patients were in NYHA function class III-IV with FEV 1 46±18%, FVC 45±17%, DL CO 24±14% and total lung capacity 51±17% of predicted. Predictors of PH were confined to PaO 2 , DL CO and 6-minute walk distance. Median survival in non-transplanted patients was less than 1 year. 20 patients died with PH, (median survival 129 days, range 22-1959 days) and 17 died without PH (median 291 days, range 12-3992 days (p=0.45). The 5-year survival in IPF patients was 35% with PH vs 40% without PH (p=0.26), in multivariable analysis, PH was associated with a HR of 0.83 (p=0.68). Similarly, no difference was observed in survival after lung transplantation (p=0.23). Conclusions PH was present in 49% of patients with end-stage IPF. Hypoxemia, DL CO and 6-minute walk distance were predictive factors. PH appears to have no significant effect on survival in end-stage IPF, either before or after lung transplantation; but IPF itself determines survival.