Clinical Impact of the Lung Allocation Policy: A Nationwide Study

Abstract

<h3>Purpose</h3> In the Italian lung transplant (LTX) allocation system, patients receive national priority (NP) only if on ECMO or mechanical ventilation (MV). We hypothesized that LAS could contribute to identify patients with increased waitlist mortality and who could benefit from NP. <h3>Methods</h3> We retrospectively reviewed the outcome and calculated the entry list LAS of patients who were listed for LTX in Italy between 2015 and 2021 either with or without NP. Probability of LTX was estimated using a competitive risk survival analysis. Postoperative 1-yr and 3-yr outcome was calculated with the Kaplan-Meier model. <h3>Results</h3> 1031 patients listed for LTX in the study period (85.3%) had complete data for analysis. 119 (11.5%) were listed with NP and 912 without. Mean LAS was 38.6 in the standard listing group and 50.1 in the NP group (p=0.0001). After stratifying for the value of LAS at the time of listing, more patients (43%) were listed with NP in the 4^thquartile (LAS>50) group. The probability of LTX was lower in patients in the LAS>50 quartile who were not placed on NP. The same group had the highest risk of death on the list (20.73%, p<0.001 compared to all other groups). Post-transplant outcomes were available for 481 patients out of 548 who received LTX in the study period (92.5%). 66 patients (13.7%) were transplanted after being on NP. 1-yr KM survival was less favorable in NP patients compared to non-NP patients, although not reaching statistical significance (p=0.08). In the >50 LAS quartile, 36.7% of patients were transplanted on the NP list, and had a worse KM survival compared to other quartiles (p=0.02). <h3>Conclusion</h3> In a non-LAS allocation context, retrospective analysis shows that high-LAS patients (>50) who do not receive NP allocation display high mortality on the waiting list. NP patients (ECMO/MV) have the worse postoperative outcomes. High LAS (>50) may earlier identify patients who are at higher risk of pre-transplant mortality and need NP, preventing the high postoperative mortality of LTX after ECMO/MV.