Impact of lung allocation score on survival in cystic fibrosis lung transplant recipients

Abstract

The lung allocation score (LAS) has changed organ allocation for lung transplantation in the United States. Previous investigations of transplant recipients reported an association between high LAS and an increased risk of death after lung transplantation. We hypothesize that a high LAS predicts survival in lung transplant recipients with cystic fibrosis (CF) in the United Network for Organ Sharing Scientific Registry of Transplant Recipients database. A cohort study was conducted of 1,437 U.S. adult lung transplant recipients with CF from May 1, 2005, through December 31, 2012. The cohort was divided into a high-risk group and a low-risk group based on LAS. Survival data were examined using Kaplan-Meier estimates and Cox proportional hazard models to compare survival. The primary outcome was adjusted survival at 1 year after lung transplantation. The high-risk group of 318 patients with a median LAS of 69.6 (interquartile range 56.3-87.2) was compared with a low-risk group of 1,119 patients with a median LAS of 38.8 (interquartile range 36.3-42.3). Patients in the high-risk group had a 41% increased relative risk of cumulative mortality at 1 year after transplantation compared with the low-risk group (16.1% vs 12.0%). After adjustment for known predictors of mortality, the risk of death at 1 year after transplantation remained elevated (hazard ratio = 1.41; 95% confidence interval = 1.00-2.01). The high-risk group had worse survival at 90 days and 2 years after lung transplantation. High LAS are associated with worse survival in lung transplant recipients with CF.