An Acute Change in Lung Allocation Score and Survival After Lung Transplantation

Abstract

Background Lung transplantation is an effective treatment for patients with advanced lung disease. In the United States, lungs are allocated on the basis of the lung allocation score (LAS), a composite measure of transplantation urgency and utility. Clinical deteriorations result in increases to the LAS; however, whether the trajectory of the LAS has prognostic significance is uncertain. Objective To determine whether an acute increase in the LAS before lung transplantation is associated with reduced posttransplant survival. Design Retrospective cohort study of adult lung transplant recipients listed for at least 30 days between 4 May 2005 (LAS implementation) and 31 December 2010 in the United Network for Organ Sharing registry. An acute increase in the LAS was defined as an LAS change (LASΔ) greater than 5 units between the 30 days before and the time of transplantation. Multivariable Cox proportional hazards models were used to examine the relationship between an LASΔ >5 and posttransplant graft survival. Setting All U.S. lung transplantation centers. Patients 5749 lung transplant recipients. Measurements Survival time after lung transplantation. Results 702 (12.2%) patients experienced an LASΔ >5. These patients had significantly worse posttransplant survival (hazard ratio, 1.31 [95% CI, 1.11 to 1.54]; P = 0.001]) after adjustment for the LAS at transplantation and other clinical covariates. The effect of an LASΔ >5 was independent of the LAS at transplantation, underlying diagnosis, center volume, or donor characteristics. Limitation Analysis was based on center-reported data. Conclusion An acute increase in LAS before transplantation is associated with posttransplant survival after adjustment for LAS at transplantation. Further emphasis on serial assessment of the LAS could improve prognostication after transplantation.

Impact of the Lung Allocation Score on Survival Beyond 1 Year

“…However, median follow‐up in our post‐LAS cohort was less than 2 years and the decline in survival occurring after the first year in the post‐LAS cohort suggests that worse overall survival may be observed with longer follow‐up. Similar to our findings, a recent analysis found that patients with an acute rise of >5 points in their LAS within 30 days of transplant had worse posttransplant survival suggesting that prioritizing acutely deteriorating patients may also adversely impact survival independent of absolute LAS .…”

Transplant in the 21st century

“…35 A change in the LAS in 2005 has led to a decrease in the number of patients who die while on the waiting list, but posttransplant deaths also have increased. 36 The increase in a patient's LAS score right before transplant seems to be the most predictive factor in death after lung transplant; thus, serial measurements are encouraged.…”

Estimating restricted mean treatment effects with stacked survival models

“…However, previous studies have only estimated the hazard ratio outside of a causal framework. Therefore, we estimate the restricted mean treatment effect of post-transplant survival between high-volume centers (more than 100 lung transplants over the past 2 years [20]) and low-volume centers (less than, or equal to, 100 lung transplants over the past 2 years) with data from an observational registry of post-lung transplant survival. The UNOS collects patient information, donor information, and survival status of every solid organ transplant performed in the USA.…”