Impact of Pulmonary Hypertension on Posttransplant Survival of Patients With Pulmonary Fibrosis at High Altitude: A Prospective Cohort Study.

Background: Pulmonary hypertension (PH) in patients undergoing lung transplantation (LT) for pulmonary fibrosis can impair lung function, reduce physical activity, and decrease survival. However, data on outcomes at 1 and 5 years of follow-up remain limited. Methods: In this prospective cohort study, pulmonary function, the 6-min walk test (6MWT), and the St. George's Respiratory Questionnaire (SGRQ) were assessed pretransplant, at hospital discharge, and at 3, 6, and 12 months posttransplant. Additionally, minimal clinically important differences (MCIDs) between patients with and without PH were evaluated. Survival rates were calculated using the Kaplan-Meier method and analyzed using the log-rank test. Results: The study included 39 patients undergoing LT for pulmonary fibrosis. Of these, 82% (32/39) had PH, with a median age of 52.6 years (SD: 10.2). In both the PH and non-PH groups, lung function, 6MWD, and SGRQ total scores showed progressive improvement from pre-LT to 1 year posttransplant. Patients without PH demonstrated MCID in 6MWT and SGRQ total scores from pre-LT through the 6- and 12-month follow-up. The overall 1-year survival rate was 84.6%, with an average survival of 10.51 months (95% CI: 9.29-11.73). The 5-year overall survival rate was 61.5%, with an average survival of 44.89 months (95% CI: 37.62-52.16). No statistically significant differences in survival were found based on sex (p=0.322 and 0.206), mean pulmonary artery pressure (mPAP) (p=0.232 and 0.486), age (p=0.375 and 0.959), or body mass index (BMI) (p=0.884 and 0.594) at 1 and 5 years. Conclusion: Survival at 1 and 5 years was lower in patients with PH. However, no significant differences in survival were observed based on sex, mPAP, age, or BMI. Statistically significant improvements in FVC, FEV1, 6MWT, and SGRQ total scores were observed both before and after LT, continuing through 1 year of follow-up. The 6MWT and SGRQ showed MCID both prior to surgery and during follow-up at 6 and 12 months, in both PH and non-PH patients.