(318) Peripheral Blood Cytokines Predict Primary Graft Dysfunction after Lung Transplantation

Purpose: Hospital free days (HFD) are increasingly utilized as an outcome measure in serious illness.We sought to assess the association between HFD during the first year after lung transplantation (LTX) and subsequent survival.We also explored the determinants of HFD in this population.Methods: All LTX recipients who survived 1 year at our institution from 2013-2021 were included.Retransplants and multi-organ transplants were excluded.HFD during the first year included the initial transplant episode and were extracted from the electronic medical record.The primary outcome was time to death.Time to onset of chronic lung allograft dysfunction (CLAD) was a secondary endpoint.The relationship between HFD and outcome was adjusted for several clinically relevant variables.Results: During this time frame, 255 LTX were performed at our institution and 241 survived at least one year.Median age was 65 with an interquartile range of [59,69], 58% were male, and 73% were bilateral LTX.Indications for transplant were LAS diagnostic groups A (78, 32%), B (8, 3%), C (14, 6%), and D (141, 59%).42 died after one year and 199 survived.Kaplan-Meier survival estimates at 3 and 5 years post-transplant were 91% and 76%, respectively.23 of the deaths were caused by graft failure, 5 from malignancy, 4 from infection, 4 from heart failure or cardiogenic shock, and 6 from other causes or unknown.CLAD was observed in 45 subjects during follow-up with CLAD-free estimates at 3 and 5 years of 83% and 73%, respectively.HFD were strongly associated with survival (p=0.01).The median number of HFD was 344 among survivors vs. 334 in non-survivors.In a multivariate analysis, adjusted for demographics, procedure type, acute kidney injury (AKI), primary graft dysfunction (PGD), and acute rejection, HFD were associated with time to death (p=.037).For every day increase in HFDs, the risk of death decreased by 1.4%.HFD did not have an association with CLAD.Our model assessing determinants of HFD showed significant association with AKI (b = -17.25,p < 0.00) and PGD (b =-12.32,p =0.003) Conclusion: This study supports the utility of using HFD as an independent predictor of survival.If validated in large multi-center cohorts, this outcome could be a useful surrogate for long-term survival in interventional trials.