The correlation of stress hyperglycemia ratio with severe acute kidney injury among patients after cardiac surgeries: A retrospective study using the MIMIC database

Stress hyperglycemia ratio (SHR) has been identified as an independent risk factor for acute kidney injury (AKI) in specific populations. However, its relationship with severe AKI among patients undergoing cardiac surgeries remains unclear. This study aimed to explore the association between postoperative SHR and severe AKI in this population. A retrospective cohort study was conducted using data from the MIMIC-IV (v3.1) database. Adult patients (≥18 years) with first-time ICU admissions after cardiac surgeries were included. Severe AKI (KDIGO Stage II–III) served as the primary endpoint, while in-hospital death and ICU length of stay were secondary endpoints. Patients were divided into high SHR (≥1.256) and low SHR (<1.256) groups based on an optimal cut-off. Cox regression, cumulative incidence curves, subgroup, and linear regression analyses were performed to assess associations. A nomogram was developed to predict severe AKI within 3 and 7 days post-surgery. Among 3,867 patients, 1,772 (45.8%) developed severe AKI and 26 (0.7%) died in hospital. High SHR was significantly associated with increased risks of severe AKI (HR=1.186, 95% CI: 1.025-1.373, P=0.022) and in-hospital death (HR=2.964, 95% CI: 1.214-7.237, P=0.017), and longer ICU stay (β=0.461, 95% CI: 0.190-0.733, P<0.001). The nomogram demonstrated moderate predictive ability (AUC=0.702 at 3 days, 0.655 at 7 days). postoperative SHR ≥1.256 is associated with elevated risks of severe AKI, in-hospital death, and prolonged ICU stay following cardiac surgeries. SHR may serve as a useful prognostic marker in this setting.