Yong-Wei Huang ¹ Zongping Li ¹ Jianjun Wang ^2,3 Decai Wang ^3,4* Xiaoshuang Yin ^5*

• ¹ Department of Neurosurgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China (UESTC), Mianyang, Sichuan, China., Mianyang, China
• ² Department of Hepatobiliary Surgery, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China (UESTC), Mianyang, China., mianyang, China
• ³ NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China (UESTC), Mianyang, China., Mianyang, China
• ⁴ Department of Urology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China (UESTC), Mianyang, China., Mianyang, China
• ⁵ Department of Immunology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China (UESTC), Mianyang, Sichuan, China., Mianyang, China

We aim to ascertain the extent to which the blood urea nitrogen to serum albumin ratio (BAR) could be implemented to anticipate the short-and long-term prognosis of acute ischemic stroke (AIS) patients in intensive care units (ICUs).The data was derived from the MIMIC-IV v3.0 database, primarily pertaining to AIS patients as categorized by the ICD-9 and ICD-10. The outcomes encompassed short-term ACM incorporating ICM admissions and 30-day , as well as longer-term ACM involving 90-day and 365-day. Any confounding effects were mitigated with a 1:1 propensity score matching approach. We determined the critical BAR level affecting patient survival with the use of maximum chosen rank statistics. The connection between BAR and ACM at various time intervals was ascertained with the multivariate Cox regression (MCR) models after the adjustment for covariates. Kaplan-Meier (KM) survival curves were generated to illustrate variations in BAR and death over various time intervals. Additionally, the linear or nonlinear connection between BAR and ACM was ascertained with restricted cubic spline (RCS) approaches, supplemented by interaction and subgroup analyses.Results: Prior to PSM, we incorporated 1764 suitable subjects with a median BAR of 5.52 mg/g. This cohort was composed of 1,395 and 369 patients in the BAR < 10.42 and ≥ 10.42 groups, respectively. After fully adjustment, MCR models indicated a heightened mortality risk for the ICU, 30-day , 90-day , and 365-day in the high BAR group as opposed to the low BAR group. Following PSM, the analysis included 352 matched patient pairs, revealing persistent links between the higher BAR group and increased ACM risk throughout ICU, 30-, 90-, and 365-day intervals. In this retrospective cohort study, our findings reveal that a confluence of deteriorated nutritional and renal function is significantly linked to heightened risks of ACM, and BAR may operate as an effective predictive indicator for AIS patients in ICUs. These findings have substantial importance for public health policy and practice. A comprehensive knowledge of these linkages may enable public health specialists and researchers to formulate more precisely targeted drugs and policies tailored to the unique requirements of the AIS patient group, hence improving their health outcomes.