(247) - Lung Transplant Waitlist Mortality: Height as a Predictor of Poor Outcomes

Abstract

PurposeThe lung allocation score (LAS) was designed to minimize pre-transplant mortality while maximizing post-transplant outcomes. Recipients under 12 years are not allocated lungs based on LAS. Since adoption of the LAS, waitlist mortality has decreased for those >12, but not for <12, suggesting this population may be disadvantaged. While age is used as the cut-off for lung allocation based on LAS, we sought to determine a more appropriate predictor of waitlist mortality.MethodsWe performed a retrospective analysis of the United Network of Organ Sharing (UNOS) database focusing on stature for those listed for transplant since LAS implementation in May 2005. Competing risk regression, Kaplan-Meir survival analysis and Cox proportional hazard modeling were used to assess pre- and post-transplant outcomes.ResultsThere were 16,973 patients listed for lung transplant since LAS implementation. 12,070 (71.1%) were transplanted and 2,498 (14.7%) patients died or were removed from the waitlist. Significantly more pediatric patients died or were removed compared to adults (22.0% vs. 14.4%, p<0.01). Patients whose height at listing was ≤1.25m and 1.25-1.5m had significantly increased waitlist mortality compared to those >1.5m (p=0.015 and p<0.001 respectively) (Figure 1a). While in univariate analysis younger age was associated with increased risk of pre-transplant mortality (HR 1.004, 95% CI 1.001-1.007), in multivariate analysis, only shorter height (adj. HR 1.008, 95% CI 1.006-1.010), male gender (1.210, 1.110-1.319), higher LAS (1.058, 1.055-1.060), and requiring extracorporeal membrane oxygenation (ECMO) (1.613, 1.202-2.163) were associated with pre-transplant mortality. Post-transplant survival was not affected by height (Figure 1b).Conclusion PurposeThe lung allocation score (LAS) was designed to minimize pre-transplant mortality while maximizing post-transplant outcomes. Recipients under 12 years are not allocated lungs based on LAS. Since adoption of the LAS, waitlist mortality has decreased for those >12, but not for <12, suggesting this population may be disadvantaged. While age is used as the cut-off for lung allocation based on LAS, we sought to determine a more appropriate predictor of waitlist mortality. The lung allocation score (LAS) was designed to minimize pre-transplant mortality while maximizing post-transplant outcomes. Recipients under 12 years are not allocated lungs based on LAS. Since adoption of the LAS, waitlist mortality has decreased for those >12, but not for <12, suggesting this population may be disadvantaged. While age is used as the cut-off for lung allocation based on LAS, we sought to determine a more appropriate predictor of waitlist mortality. MethodsWe performed a retrospective analysis of the United Network of Organ Sharing (UNOS) database focusing on stature for those listed for transplant since LAS implementation in May 2005. Competing risk regression, Kaplan-Meir survival analysis and Cox proportional hazard modeling were used to assess pre- and post-transplant outcomes. We performed a retrospective analysis of the United Network of Organ Sharing (UNOS) database focusing on stature for those listed for transplant since LAS implementation in May 2005. Competing risk regression, Kaplan-Meir survival analysis and Cox proportional hazard modeling were used to assess pre- and post-transplant outcomes. ResultsThere were 16,973 patients listed for lung transplant since LAS implementation. 12,070 (71.1%) were transplanted and 2,498 (14.7%) patients died or were removed from the waitlist. Significantly more pediatric patients died or were removed compared to adults (22.0% vs. 14.4%, p<0.01). Patients whose height at listing was ≤1.25m and 1.25-1.5m had significantly increased waitlist mortality compared to those >1.5m (p=0.015 and p<0.001 respectively) (Figure 1a). While in univariate analysis younger age was associated with increased risk of pre-transplant mortality (HR 1.004, 95% CI 1.001-1.007), in multivariate analysis, only shorter height (adj. HR 1.008, 95% CI 1.006-1.010), male gender (1.210, 1.110-1.319), higher LAS (1.058, 1.055-1.060), and requiring extracorporeal membrane oxygenation (ECMO) (1.613, 1.202-2.163) were associated with pre-transplant mortality. Post-transplant survival was not affected by height (Figure 1b). There were 16,973 patients listed for lung transplant since LAS implementation. 12,070 (71.1%) were transplanted and 2,498 (14.7%) patients died or were removed from the waitlist. Significantly more pediatric patients died or were removed compared to adults (22.0% vs. 14.4%, p<0.01). Patients whose height at listing was ≤1.25m and 1.25-1.5m had significantly increased waitlist mortality compared to those >1.5m (p=0.015 and p<0.001 respectively) (Figure 1a). While in univariate analysis younger age was associated with increased risk of pre-transplant mortality (HR 1.004, 95% CI 1.001-1.007), in multivariate analysis, only shorter height (adj. HR 1.008, 95% CI 1.006-1.010), male gender (1.210, 1.110-1.319), higher LAS (1.058, 1.055-1.060), and requiring extracorporeal membrane oxygenation (ECMO) (1.613, 1.202-2.163) were associated with pre-transplant mortality. Post-transplant survival was not affected by height (Figure 1b). Conclusion