The U-shaped association of post-lung transplant mortality with pretransplant eGFR underscores possible limitations of creatinine-based estimation equations for risk stratification.

Abstract

Pre-existing chronic kidney disease (CKD) may have an impact on post-lung transplant survival and the development of end stage kidney disease (ESKD). We analyzed the US transplant database from 2006 to 2020. Adult patients who received their first lung transplant and were not on dialysis were included. Multivariable Cox regression was used to assess the effect of pretransplant eGFR on mortality and cumulative incidence competing risk was used to explore the effect on ESKD. The adjusted hazard ratio (aHR) for mortality showed a "U" shaped association with eGFR with a rising mortality at <60 and >100 ml/min/1.73m2. The increase in mortality with higher eGFR was only seen in those <30 year and were primarily in whites with a lower body mass index and in patients with cystic fibrosis (CF). The aHR for ESKD increased below an eGFR of 100 rising to 1.74 at an eGFR of 60. Any decrease in eGFR between listing and transplant >10% was associated with higher risk of ESKD. The U-shaped association of pretransplant eGFR with post-transplant mortality correlated with younger age, lower BMI and a diagnosis of CF. The aHR for ESKD following lung transplantation increased exponentially with worsening eGFR pretransplant.