Age-related survival disparity associated with lung transplantation in cystic fibrosis: An analysis of the registry of the International Society for Heart and Lung Transplantation

Abstract

Background: A survival advantage has been demonstrated for lung transplantation (LTx) in the cystic fibrosis (CF) population, but children may be at higher risk of post-transplant mortality than adults.

Methods: The registry of the International Society for Heart and Lung Transplantation (ISHLT) was queried for lung transplants performed during the period 1998 to 2014 in patients with CF. Period differences were assessed by dividing the sample into LTxs performed between 2006 and 2014 and those performed between 1998 and 2005. Age ≥18 years distinguished adult from pediatric recipients. Supplemental analyses of United States of America (USA) LTx recipients with CF utilized 1998 to 2014 data from the United Network for Organ Sharing (UNOS) registry.

Results: A total of 7,245 patients from the ISHLT registry were selected for analysis. Kaplan-Meier curves confirmed a survival disadvantage of children as compared to adults with CF in 2006 to 2014 (p<0.001), and in the earlier era of 1998 to 2005 (p = 0.002). Univariate Cox proportional hazards regression revealed that age <18 years at transplantation [hazard ratio (HR) = 1.367; 95% confidence interval (CI) 1.225 to 1.526; p < 0.001] and LTxs performed in 1998 to 2005 (HR = 1.131; 95% CI 1.042 to 1.227; p = 0.003) were associated with greater mortality hazard. Multivariable Cox regression adjusting for potential confounders and interacting LTx era with recipient age group confirmed the persistence of age-related survival disparities after LTx in CF in the contemporary era. Analysis of UNOS data demonstrated survival disparities between children and adult CF patients receiving LTx in majority-adult programs.

Conclusions: An age-related survival disparity after LTx has persisted in the international CF population. Data from the USA suggest this disparity is not fully explained by differences in center volume between adult and pediatric programs in the contemporary era.

Keywords: adult; age; children; cystic fibrosis; lung transplantation; pediatric; survival.