Lung Transplant Mortality Is Improving in Recipients With a Lung Allocation Score in the Upper Quartile

Abstract

Background: Since the introduction of the Lung Allocation Score (LAS), the mean LAS has risen. Still, it remains uncertain whether mortality has improved in the most severely ill lung transplant recipients over this time period.

Methods: Using the United Network for Organ Sharing database, we identified 3,548 adult lung transplant recipients from May 4, 2005, to March 31, 2014, with a match-time LAS in the upper quartile (>75th%ile). We divided this population across three eras: 1 = May 4, 2005, to December 31, 2008 (n = 1,280); 2 = January 1, 2009, to December 31, 2011 (n = 1,266); and 3 = January 1, 2012, to March 31, 2014 (n = 1,002). Cox proportional hazards models were constructed for the primary outcomes of 30-day and 1-year mortality to assess the independent impact of the era of transplantation.

Results: The mean LAS at time of transplant for patients in the upper quartile in eras 1, 2, and 3 was 63, 73, and 79, respectively (p < 0.001). Later eras of transplantation benefited from a significant improvement in survival at 1 year (log-rank p = 0.001) but not at 30 days (log-rank p = 0.152). After risk adjustment, lung transplantation in more recent eras was associated with improved mortality at both 30 days (era 3 hazard ratio [HR] = 0.50, 95% confidence interval [CI] 0.32% to 0.78%, p = 0.002) and 1 year (era 2 HR = 0.77, 95% CI 0.64% to 0.94%, p = 0.008; era 3 HR = 0.54, 95% CI 0.43% to 0.68%, p < 0.001).

Conclusions: Despite a progressively rising LAS, survival is improving among recipients with the highest LAS at the time of lung transplantation. This calls into question the notion of a maximum LAS beyond which lung transplantation becomes futile, a so-called LAS ceiling.