Epidemiology and outcomes of acute kidney injury in cardiac intensive care unit patients.

PURPOSE

To describe the epidemiology and outcomes of acute kidney injury (AKI) among contemporary non-surgical cardiac intensive care unit (CICU) patients.

MATERIALS AND METHODS

We reviewed adult non-surgical CICU patients admitted from 2007 to 2015. The highest AKI stage during hospitalization was defined using modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria, based on changes in serum creatinine. Hospital and 5-year mortality were examined using logistic regression and Cox proportional-hazards models, respectively.

RESULTS

We included 9311 patients with a mean age of 67.5 years, including 37% females. AKI was present in 51%: stage 1 AKI in 34%, stage 2 AKI in 9%, and stage 3 AKI in 8%. Hospital mortality was associated with AKI stage (adjusted OR for each AKI stage 1.17, 95% CI 1.04-1.31, p = 0.007). Five-year mortality was incrementally associated with AKI stage (adjusted HR per AKI stage 1.13, 95% CI 1.08-1.18; p < 0.001), particularly post-discharge mortality among hospital survivors (adjusted HR per AKI stage 1.20, 95% CI 1.15-1.25, p < 0.001). Patients with stage 3 AKI (especially requiring dialysis) had the highest adjusted hospital and five-year mortality.

CONCLUSION

AKI severity is incrementally associated with higher short-term and long-term mortality in CICU patients, especially severe AKI requiring dialysis.