Association of HRS-AKI with Mortality in Patients with Cirrhosis Requiring Renal Replacement Therapy

Background: While AKI requiring renal replacement therapy (AKI-RRT) is associated with increased mortality in heterogeneous inpatient populations, the epidemiology of AKI-RRT in hospitalized patients with cirrhosis is not fully known. Herein, we evaluated the association of etiology of AKI with mortality in hospitalized patients with cirrhosis and AKI-RRT in a multicentric contemporary cohort. Methods: This is a multicenter retrospective cohort study using data from the HRS-HARMONY consortium, which included 11 U.S. hospital network systems. Consecutive adult patients admitted in 2019 with cirrhosis and AKI-RRT were included. The primary outcome was 90-day mortality, and the main independent variable was AKI etiology, classified as hepatorenal syndrome (HRS-AKI) vs. other (non-HRS-AKI). AKI etiology was determined by at least two independent adjudicators. We performed Fine and Gray sub-distribution hazard analyses adjusting for relevant clinical variables. Results: Of 2,063 hospitalized patients with cirrhosis and AKI, 374 (18.1%) had AKI-RRT. Among these, 65 (17.4%) had HRS-AKI and 309 (82.6%) non-HRS-AKI, which included ATN in most cases (62.6%). Continuous RRT (CRRT) was used as the initial modality in 264 (71%) of patients, while intermittent hemodialysis (IHD) was utilized in 108 (29%). The HRS-AKI (vs. non-HRS-AKI) group received more vasoconstrictors for HRS management (81.5% vs. 67.9%), while the non-HRS-AKI group received more mechanical ventilation (64.3% vs. 50.8%) and more CRRT (vs. IHD) as the initial RRT modality (73.9% vs. 56.9%). In the adjusted model, HRS-AKI (vs. non-HRS-AKI) was not independently associated with increased 90-day mortality (sHR=1.36, 95% CI: 0.95-1.94). Conclusions: In this multicenter contemporary cohort of hospitalized adult patients with cirrhosis and AKI-RRT, HRS-AKI was not independently associated with an increased risk of 90-day mortality when compared to other AKI etiologies. The etiology of AKI appears less relevant than previously considered when evaluating the prognosis of hospitalized adult patients with cirrhosis and AKI requiring RRT.