Acute kidney injury stage 1a increases mortality of patients with cirrhosis: a prospective multicenter cohort study.

Background and aims: Acute kidney injury is a severe complication of cirrhosis. However, the impact of mild decreases in renal function is controversial. This study aims to evaluate the prognosis of the different stages of acute kidney injury in cirrhosis.

Methods: This is a multicenter prospective cohort study of patients hospitalized for acute decompensation of cirrhosis, with serum creatinine values measured at least twice. Primary outcome was mortality (in-hospital, 30 days, 90 days and 12 months).

Results: Nine hundred twenty-eight patients were included in the study. Acute kidney injury was diagnosed in 505 patients (stages 1a-21.6%, 1b-27.5%, 2-28.1%, 3-22.8%). Mortality rates of patients with acute kidney injury stage 1a were significantly higher than those of individuals without acute kidney injury (in-hospital-19.3% vs 4.7%; 30-day-21.8% vs 6.7%; 90-day-35.2% vs 17.5%; 12-month-54.1% vs 37.1%; p < 0.05 for all comparisons). Mortality rates were even higher for acute kidney injury stages 1b, 2 and 3. Survival analysis demonstrated that patients without acute kidney injury performed significantly better than those with any stage of acute kidney injury (p < 0.01). Acute kidney injury stages 1a, 1b, 2 and 3 were independently associated with survival in the multivariate analysis (p < 0.01).

Conclusions: Patients hospitalized for acute decompensation of cirrhosis who develop acute kidney injury have significantly higher mortality rates than those who do not develop this complication. This is true even for the mildest stages of acute kidney injury (stage 1a) and remains so at different time-points, supporting recommendations for earlier treatments.