Acute kidney injury (AKI) is a common complication in patients hospitalized with heart failure (HF). There is a paucity of research on the incidence and consequences of AKI among patients hospitalized with HF who do not have evidence of chronic kidney disease (CKD). The National Inpatient Sample database was used to identify index hospitalizations for acute HF from January 2012 through September 2015. The incidence of new-onset AKI was determined, and the study population was divided into two groups: HF with AKI (HFwAKI) and HF without AKI (HFwoAKI). These groups were further divided into the subgroups HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). A total of 2,010,095 index hospitalizations for HF were identified. The incidence of new-onset AKI was found to be ~ 20% for this population. In a fully adjusted model, in-hospital mortality was higher in the HFwAKI group (adjusted OR 3.63, P ≤ 0.001) and higher among patients with HFrEF (adjusted OR 3.85), as opposed to patients with HFpEF (adjusted OR 3.21). Similarly, length of stay and cost of care for the HFwAKI group were significantly higher as well. New-onset AKI among hospitalizations for HF poses a significant health problem, especially considering the increasing prevalence of HF. Further research into the causes of AKI among HF hospitalizations is, therefore, important as it will enable the development of treatment strategies to prevent AKI in HF hospitalizations and, consequently, benefit both the patients and health care system of the United States.
Keywords: Heart failure; In-hospital mortality; Incidence; New-onset acute kidney injury.