Acute Lung Injury in Interstitial Lung Disease is Not Associated with Post Transplant Survival

Abstract

<h3>Purpose</h3> Patients with interstitial lung diseases (ILD) may develop acute lung injury (ALI), leading to increased mortality. We aimed to determine whether ILD patients with ALI on explant pathology have different post-transplant survival than those with stable disease. <h3>Methods</h3> In a single center retrospective cohort study of 279 adult lung transplant recipients with ILD from January 1, 2004 to December 31, 2019, we identified those with ALI (diffuse alveolar damage, organizing pneumonia, hemorrhage, edema) on explant pathology. We used multivariable Cox regression to evaluate the association with post-transplant survival and ALI status. Age and sex were added to each model <i>a priori</i>; other risk factors were added based on univariable analysis. <h3>Results</h3> Our cohort was 78% male with a median age 59.3 (IQR 54.4-63.8) years; 65% had idiopathic pulmonary fibrosis. 37/279 patients (13.3%) had ALI at time of transplant. 29.7% of recipients with ALI required extra-corporeal life support (ECLS) and/or invasive ventilation pre-transplant, compared to 7.4% without ALI (p<0.001). Patients with ALI were more likely to require pre-transplant hospitalization (56.8% vs. 15.3%, p<0.001). ICU and post-transplant hospital length of stay were similar between both groups. The crude HR between ALI status and post-transplant survival was 1.30 (95% CI 0.77-2.21), p=0.33 (Figure 1). There was no association between ALI status and post-transplant survival (HR 1.65 (95% CI 0.94-2.91), p=0.08) after adjusting for age, sex, intra-operative circulatory support, recipient body mass index, transplant era, and ventilation or ECLS bridge to transplant. <h3>Conclusion</h3> Although recipients with ALI on explant pathology were sicker, suggested by the increased number of patients requiring hospitalizations prior to transplant, post-transplant survival was not affected. Future work into whether clinical features of ILD exacerbation mimic this relationship and whether there is an association with PGD and CLAD risk are required.