The Lung Allocation Score Remains Inequitable for Patients with PAH, Even After the 2015 Revision

Abstract

<h3>Purpose</h3> The 2015 LAS revision intended to improve waitlist mortality and transplant rate for patients with pulmonary arterial hypertension (PAH). We sought to determine if the revision achieved its goals. <h3>Methods</h3> Using the OPTN STAR file, we analyzed the 15,807 registrants in the 3-year period before and after the revision. Registrants were divided into the LAS diagnostic categories: Group A-COPD; Group B-PAH; Group C-CF; & Group D-IPF. Competing risk regressions assessed the mutually exclusive competing risks of waitlist death and transplantation. Models were adjusted for age, gender, race, height, transplant type, and blood type. Cumulative incidence plots were created to visually inspect risks. <h3>Results</h3> Amongst the combined cohort, risk of waitlist death was lower post revision (sHR: 0.84, 95%CI: 0.78, 0.91), and likelihood of transplant was higher (sHR: 1.16, 95%CI: 1.12, 1.21). When stratified by LAS Category, risk of waitlist death remained similar for all diagnoses post revision, except in PAH, where risk of waitlist death improved (sHR: 0.57, 95%CI: 0.50, 0.85). Likelihood of transplant improved for all diagnoses post revision (all p<0.001). Prior to the revision, registrants with PAH had the highest risk of waitlist death and lowest likelihood of transplant (Figure). After the 2015 revision, registrants with PAH continued to have the highest risk of death, similar to those with IPF, who had the highest rate of transplant (sHR for IPF relative to PAH: 0.95, 95%CI: 0.67, 1.33). Registrants with PAH also continued to have the lowest rate of transplant, and registrants with COPD, which had the lowest risk of waitlist death, still tended to be transplanted at a higher rate than those with PAH (sHR for COPD relative to PAH 1.14, 95%CI: 0.99, 1.31). <h3>Conclusion</h3> Despite improving access to transplantation and risk of waitlist death for patients with PAH, the 2015 LAS revision did not go far enough, as patients with PAH still have the highest rate of waitlist death and lowest rate of transplant.