Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH.
Department of Anesthesiology, The Ohio State University College of Medicine, Columbus, OH.
Chest. 2019 Jul;156(1):64-70. doi: 10.1016/j.chest.2019.01.008. Epub 2019 Jan 18.
The lung allocation score (LAS) prioritizes lung transplant (LTx) candidates with poor transplant-free survival and expected survival benefit from LTx. Although patients with the highest LAS have the shortest waiting time, mortality benefit is unclear in this group, raising criticism that the LAS inappropriately prioritizes critically ill candidates. We aim to identify a threshold above which increasing LAS values do not predict increasing survival benefit.
The United Network for Organ Sharing Registry was queried for first-time adult LTx candidates with LAS ≥ 30 between May 2005 and December 2016. Survival was tracked from the time of listing through the posttransplant period and compared with survival while remaining on the waitlist, using proportional hazards regression. The survival benefit of LTx was modeled as a piecewise-constant time-dependent covariate, moderated by candidate LAS.
Of the overall cohort (N = 21,157), LTx was particularly protective for 365 patients with an initial LAS of 70 to 79 (hazard ratio of death after undergoing LTx relative to remaining on the waitlist, 0.2; 95% CI, 0.1-0.3). However, the survival benefit of LTx did not meaningfully increase for 1,042 patients listed with even higher LAS. Among patients with cystic fibrosis, the survival benefit of LTx was constant above an LAS of approximately 50.
Consistent survival benefit of LTx was observed among patients with an initial LAS of 70 and greater. This result supports equalizing priority for donor lung allocation for patients with LAS ≥ 70. A lower LAS threshold for maximum priority is indicated in patients with cystic fibrosis.
肺分配评分（LAS）优先考虑移植后无生存获益且预计从移植中获益的肺移植（LTx）候选者。尽管 LAS 最高的患者等待时间最短，但该组患者的死亡率获益并不明确，这引发了对 LAS 不适当地优先考虑重症候选者的批评。我们旨在确定 LAS 值增加不再预测生存获益增加的阈值。
在 2005 年 5 月至 2016 年 12 月期间，通过美国器官共享网络检索了 LAS≥30 的首次成人 LTx 候选者的登记数据。使用比例风险回归，从列入名单开始，通过移植后时期跟踪生存情况，并与等待名单上的生存情况进行比较。将 LTx 的生存获益建模为一个分段常数时间依赖协变量，由候选者 LAS 调节。
在整个队列中（n=21157），LTx 对 365 名初始 LAS 为 70 至 79 的患者特别有保护作用（LTx 后死亡的相对风险比，0.2；95%CI，0.1-0.3）。然而，对于 LAS 更高的 1042 名患者，LTx 的生存获益并没有显著增加。在囊性纤维化患者中，LTx 的生存获益在 LAS 约为 50 以上时保持不变。
在初始 LAS 为 70 及以上的患者中，观察到 LTx 的一致生存获益。这一结果支持为 LAS≥70 的患者提供平等的供肺分配优先级。对于囊性纤维化患者，需要较低的 LAS 阈值以获得最大优先级。
