The association of statin use with in-hospital mortality in patients with acute kidney injury during hospitalization: A retrospective analysis.

Aim: Acute kidney injury (AKI) is a severe condition in hospitalized patients and carries high mortality. The influence of statin use on the outcomes of AKI patients remains inconsistent. We aimed to discover the association between statin use and in-hospital mortality.

Methods: This retrospective study screened all adult admissions in Peking University First Hospital between 1 January 2018 and 31 December 2020, and patients with AKI during hospitalization were included. Exposure was defined as any statin prescription prior to AKI onset. Patients were followed up until death or discharge. The primary outcome was in-hospital all-cause mortality; secondary outcomes included cardiovascular- and sepsis-related mortality, elevated transaminases, rhabdomyolysis and kidney nonrecovery at discharge.

Results: A total of 2034 AKI patients were included. 551 (27%) patients were statin users. During a median of 10 days of follow-up, we documented 283 (14%) in-hospital deaths. Compared with statin nonusers, statin users experienced a significantly lower risk in in-hospital all-cause mortality (adjust hazard ratio [aHR], 0.54; 95% CI, 0.35-0.84) and cardiovascular-related mortality (aHR, 0.48; 95% CI, 0.24-0.97) after covariate adjustment. The survival benefit of statin use was consistent across subgroups, that is, age, sex, initial AKI stage and major surgery (all P for heterogeneity >.05). For sepsis-related mortality, elevated transaminases, rhabdomyolysis and kidney nonrecovery, the association was no longer significant in the fully adjusted model. For any type of statins, a statistically significant association was only observed in atorvastatin (aHR, 0.49; 95% CI, 0.30-0.81).

Conclusions: Statin use may improve survival, and atorvastatin may be preferred in patients with AKI.