#4185 EPISODES OF AKI FOLLOWING HOSPITALISATION AND ASSOCIATION WITH ADVERSE OUTCOMES: ANALYSIS FROM A PROSPECTIVE COHORT STUDY
Authors: Horne Kerry , Viramontes-Horner Daniela , Packington Rebecca , Shaw Sue , Akani Aleli , Reilly Tim , Monaghan John , Selby Nick 
Published: June 2023

Abstract

Background and Aims
AKI is associated with adverse long-term outcomes, including mortality, cardiovascular events and CKD development and progression. Individuals who have sustained AKI are at increased risk of developing further AKI. This analysis presents the association of long-term risk related to recent and further episodes of AKI in a prospective cohort of recently hospitalised individuals.

Method
Two matched cohorts of hospitalised individuals who had survived to at least 90 days after hospital discharge were recruited. The cohorts consisted of people who had sustained AKI during hospital admission (exposed group), and those who had not (non-exposed group), and were matched 1:1 for age, baseline eGFR stage and diabetes. Renal function, albuminuria and new AKI episodes were measured at 3 months, one, three and five years after index hospitalisation. Mortality, further AKI episodes and episodes of heart failure were recorded. Kidney disease progression was defined as decrease in eGFR of ≥25% associated with a decline in eGFR stage. Multivariable analysis was performed with binary logistic regression to assess the associations between repeated AKI episodes and outcomes.

Results
866 exposed and non-exposed participants were recruited and successfully matched. Over the 5-year follow-up period, 138 (34%) participants in the exposed group had ≥1 further AKI compared with 67 (16%) in the non-exposed group (OR 2.71 [95% CI 1.94 to 3.77]; p&lt;0.001). Independent associations with developing AKI during the follow-up period were AKI during index admission, baseline eGFR, albuminuria at 3 months and smoking status. Binary logistic regression, including all matched participants, showed that AKI during follow-up was independently associated with 5-year kidney disease progression (adjusted OR 2.49, 95% CI 1.42-4.37, p = 0.002), mortality (adjusted OR 3.076 95% CI 2.039-4.639 p&lt;0.001) and episodes of heart failure (adjusted OR 5.234 95% CI 3.355-8.164, p&lt;0.001). There was an additive effect, with the frequency of adverse outcomes increasing as number of AKI exposures increased (Table 1). Exposure to AKI during index admission or follow-up episodes conferred similar risk of kidney disease progression. AKI during the follow-up period had a stronger association with mortality and heart failure episodes than AKI during the index admission in this survivor cohort.

Conclusion
Previous AKI episodes were associated with increased frequency of future AKI episodes. AKI episodes during follow up period were independently associated with adverse outcomes regardless of AKI exposure during index hospitalisation. Increasing number of exposures to AKI had an additive effect on the proportion of individuals showing kidney disease progression, mortality and heart failure episodes. In this cohort of AKI survivors, AKI during the follow-up period had a stronger association with these outcomes than exposure to AKI during the index admission. A strategy for improving long-term outcomes in AKI survivors may be improving the identification of those at greatest risk of future AKI and strategies to prevent or optimise early detection and management.