Usefulness of the blood urea nitrogen-to-serum albumin ratio as a prognostic indicator of severity in acute ischemic stroke

Objectives: Acute ischemic stroke (AIS) is one of the most important and major causes of mortality worldwide. In AIS patients, the blood urea nitrogen to creatinine ratio (B/C ratio) was investigated as a dehydrated biomarker in previous studies. However, the B/C ratio can be affected by medications and past medical history. We hypothesized addition of serum albumin, which has been shown to have beneficial neuroprotective effects, could compensate for the disadvantages. In the present study, the BUN to serum albumin ratio (B/A ratio) was evaluated association with AIS patient's prognosis. Methods: This retrospective cohort study of AIS in our hospital was conducted from February 2018 through June 2020. First, demographic and clinical data were collected and compared with the prevalence of mortality and ICU admission. Then, the B/C ratio and the B/A ratio were calculated. Differences in the performance between the B/C ratio and the B/A ratio for outcome prediction were evaluated based on the area under the curve of the receiver operating characteristic (AUROC). Results: Among the 1,164 patients enrolled in this study, 77 (6.6%) died during hospitalization and 467 (40.1%) were admitted to ICU. Multivariate logistic regression had shown that the B/A ratio was a significant predictor of mortality and admission to ICU. In addition, the B/A ratio was significantly higher in ICU-admitted patients and non-survivors. The AUROC of the B/A ratio was 0.687 and the B/C ratio was 0.533 for predicting mortality; the B/A ratio was statistically superior to the B/C ratio. For predicting ICU admission, the AUROC values of the B/A ratio and the B/C ratio were 0.567 and 0.556, respectively, and a statistically significant difference was not observed. Conclusion: The B/A ratio is a simple and useful tool for predicting the outcomes of ischemic stroke patients.