Determining eligibility for lung transplantation: A nationwide assessment of the cutoff glomerular filtration rate.

BACKGROUND

Historical concerns about lung transplantation in patients with a glomerular filtration rate (GFR) ≤ 50 ml/min/1.73 m(2) have not been validated. We hypothesize that a pre-transplant GFR ≤ 50 ml/min/1.73 m(2) represents a high mortality risk, especially in the setting of acute GFR decline. In addition, we explore the potential for improved risk stratification using a statistically derivable alternative cutoff.

METHODS

Adult, primary, lung recipients in the United Network for Organ Sharing database were analyzed (October 1987 to December 2011). Recursive partitioning identified the GFR value that provides maximal separation in 1-year mortality. Survival over/under the cutoffs was compared using stratified log-rank, Cox, and Kaplan-Meier methods, before and after 1:2 propensity score matching.

RESULTS

Median GFR at time of transplant for 19,425 study patients was 94.2 ml/min/1.73 m(2) (quartile 1-quartile, 2 76.9-105.9 ml/min/1.73 m(2)). Recursive partitioning identified a GFR of 40.2 ml/min/1.73 m(2) as the ideal inflection point for predicting 1-year survival. Cutoffs demonstrated statistically significant effects on survival after 840 patients with a GFR ≤ 50 ml/min/1.73 m(2) (hazard ratio, 1.28; 95% confidence interval, 1.15-1.43) and 401 patients with a GFR ≤ 40.2 ml/min/1.73 m(2) (hazard ratio, 1.57; 95% confidence interval, 1.36-1.83) were matched with high GFR controls (p < 0.001). In 13,509 patients with available GFR at the time of listing and transplant, a pre-transplant GFR decline of ≥ 50% from baseline was associated with worse survival (p < 0.001).

CONCLUSIONS

A pre-transplant GFR ≤ 50 ml/min/1.73 m(2) is associated with decreased survival. However, patients with GFR between 40 and 50 ml/min/1.73 m(2) do not suffer excessive post-transplant mortality and should not be automatically excluded from listing. Notably, outcomes are worse in patients with poor renal function and concomitant pre-transplant GFR decline. Strategies should be devised to detect and manage interval renal deterioration before lung transplantation.