Prognostic significance of acute kidney injury stage 1B in hospitalized patients with cirrhosis: A US nationwide study

Background: Understanding the prognostic significance of acute kidney injury (AKI) stage-1B [serum creatinine (sCr) > 1.5 mg/dL], compared to stage-1A (sCr < 1.5 mg/dL) in an US population is important as it can impact initial management decisions for AKI in hospitalized cirrhosis patients. Therefore, we aimed to define outcomes associated with stage-1B in a nationwide US cohort of hospitalized cirrhosis patients with AKI. Material and methods: Hospitalized cirrhosis patients with AKI in the Cerner-Health-Facts database from 1/2009-09/2017 (n = 6,250) were assessed for AKI stage-1 (> 1.5-2-fold increase in sCr from baseline) and were followed for 90-days for outcomes. Primary outcome was 90-day mortality; secondary outcomes were in hospital AKI progression and AKI recovery. Competing-risk multivariable analysis was performed to determine the independent association between stage-1B, 90-day mortality (liver transplant as competing-risk) and AKI recovery (death/liver-transplant as competing-risk). Multivariable logistic regression analysis was performed to determine the independent association between stage-1B and AKI progression. Results: 4,654 patients with stage 1 were analyzed: 1A (44.3%) and 1B (55.7%). Stage-1B patients had significantly higher cumulative incidence of 90-day mortality compared to stage-1A patients, 27.2% vs. 19.7% (p < 0.001). On multivariable competing-risk analysis, patients with stage 1B (vs. 1A) had higher risk for mortality at 90-days [sHR 1.52 (95%CI 1.20-1.92), p = 0.001] and decreased probability for AKI recovery [sHR 0.76 (95%CI 0.69-0.83), p < 0.001]. Furthermore, on multivariable logistic regression analysis, AKI stage-1B (vs. 1A) was independently associated with AKI progression, OR 1.42 (95%CI 1.14-1.72) (p < 0.001). Conclusions: AKI stage-1B patients have significantly higher risk for 90-day mortality, AKI-progression, and reduced probability of AKI-recovery compared to AKI stage-1A patients. These results could guide initial management decisions for AKI in hospitalized patients with cirrhosis.