Acute kidney injury (AKI) and risk of readmissions in patients with heart failure

Abstract

Heart failure (HF) contributes to a high rate of hospitalizations. Acute kidney injury (AKI), with or without chronic kidney disease (CKD), is a common complication in patients with HF. The link between AKI and the risk for readmission for repeat episodes of HF is not well studied. In this study, 6,535 patients discharged with primary diagnoses of HF derived from a statewide inpatient database were examined. The association between AKI, with and without CKD, and risk for 30-day readmission with HF was assessed. Logistic regression was used to test the relations between predictor variables and outcomes. The mean age was 73.8 ± 14.6 years, and 51% of patients (n = 3,351) were women. AKI occurred in 6.5% of patients during the index hospitalization, whereas 16% had CKD. Nine hundred seventy-seven patients (15%) required readmission within 30 days for HF. Index hospital mortality was 1.7% in those without AKI or CKD compared to 11% and 13% in those with AKI without and with CKD, respectively (p <0.0001). Patients with AKI had a 30-day readmission rate of 21%, compared to 14% in those without AKI (p <0.0001). On multivariate analysis, AKI without CKD was associated with the highest risk for readmission (odds ratio 1.81, 95% confidence interval 1.35 to 2.39) compared to those with neither of the 2 diagnoses. In conclusion, patients with HF who have AKI experience a high rate of 30-day readmission for repeat episodes of HF. Reducing the risk for AKI, and follow-up monitoring after AKI, may improve care and reduce health care costs in patients with HF.