P0569ACUTE KIDNEY INJURY AFTER LUNG TRANSPLANTATION: INCIDENCE, RISK FACTORS AND OUTCOMES IN A MONOCENTRIC RETROSPECTIVE COHORT STUDY

Abstract

Abstract Background and Aims Acute kidney Injury (AKI) occurs in more than 50% of patients after lung transplantation (LTx). Our aim was to describe the incidence, risk factors and outcomes associated with AKI after LTx in a retrospective monocentric cohort study. Method We studied all recipients of LTx (> 16 years of age) occurring at Ospedale Maggiore Policlinico Milano between Jan 1st 2015 and Dec 31st 2017. AKI was defined according to KDIGO classification, eGFR was calculated according to CKD (Chronic Kidney Disease) Epidemiology Collaboration formula and CKD was defined by an eGFR< 60 ml/min per 1.73 m2. Chi square, Fisher exact test, t.-test and logistic regression were used to define risk factors for AKI in the early post-surgical period and for CKD at 1 and 2 years after LTx. AKI-related survival was estimated using Kaplan Meyer model. Results Of 78 LTx patients enrolled in our Center, 50% of patients was affected by cystic fibrosis. Median age at transplant was 43 years (27-55); median follow- up was 31 months (20-40). Survival rate was 80.77% at 1 year, 69.23% at 2 years and 66.67% on Dec 31st 2019 (last follow-up). AKI occurred in 42 (53.85%) patients within the first week after LTx, respectively grade I and II in 12 each (15.38%) and grade III in 18 (23.08%) patients. Pre-transplant low albumin levels and hypertension were independently associated with AKI at univariate and multivariate (p= 0.0018 and 0.0004 respectively) analysis. Pre-transplant low albumin levels, pre-transplant ECMO-use, hypertension, ECMO-use during transplant surgery were associated with severe AKI in univariate analysis but only pre-transplant hypertension and ECMO-use during transplant surgery were independently associated in the multivariate one (p=0.0266 and 0.0463 respectively). Survival was significantly reduced in patients affected by AKI (p=0.035); this observation became strongly significant when only mild and moderate (grade I and II) AKI was considered (p=0.0071). CKD was diagnosed in 38.09% of patients at 1 year and 35.18% at 2 years. While numerous risk factors were related to the occurrence of CKD at 1 and 2 years after LTx at univariate analysis, only grade III AKI remained independently associated with CKD at multivariate analysis (p= 0.0081 for 1 year-CKD, p=0.0154 for 2 year-CKD). Conclusions In our population, AKI after LTx occurred in about half of the patients and was predicted by history of hypertension, low albumin levels and hemodynamic instability during the surgery. Mild-moderate AKI, often clinically underestimated, was strongly associated with reduced survival. Severe forms of AKI were predictive of occurrence of CKD.