Data Availability
Data are available from the corresponding author on reasonable request.
Study Population
This study was approved by the Ethics Committee of the First Affiliated Hospital of China Medical University (Ethics No.: 2021-457). All research processes followed the Helsinki Declaration. We prospectively collected the acute MIS patients hospitalized in the First Affiliated Hospital of China Medical University from January 2021 to December 2021. We used the National Institutes of Health Stroke Scale (NIHSS) to distinguish the severity of stroke, and defined patients with NIHSS score less than 5 as MIS 15.
The admission criteria were: (1) age ≥ 18 years; (2) the onset time ≤ 3 days; (3) patients with AIS diagnosed by diffusion weighted imaging (DWI) for the first time; (4) NIHSS score<5; (5) agree to participate in the study and sign the written informed consent. Participants were excluded based on: (1) patients with cognitive impairment at admission; (2) patients with previous diagnosis of central nervous system diseases: (3) patients with tumors; (4) patients unable to complete the scale or related examinations due to hearing, vision or language disorders; (5) complicated with serious heart disease, such as acute myocardial infarction, acute left heart failure, etc. (6) patients receiving intravenous thrombolysis (IVT).
Demographics and basic clinical information were registered at admission. The severity of neurological function after stroke was assessed by NIHSS score, the etiology classification of stroke was assessed by TOAST classification, and the baseline cognitive function was assessed by Montreal Cognitive Assessment (MoCA). Fasting after 22:00 on the day of admission, blood samples were collected in the morning of the next day. And the blood samples were sent to the Laboratory Department of the First Affiliated Hospital of China Medical University for measurement by an automatic blood analyzer. The reference value of serum CysC ranged from 0.53 to 0.95 mg/l. Intra- and inter-assay coefficients of variation were less than 3.9% and 4.8%, respectively.
Kidney Function
Renal function was assessed by GFR estimated by serum CysC and creatinine levels. We used the Chronic Kidney Disease Epidemiology Collaboration Equation (CKD-EPI) to calculate GFR levels, expressed as eGFRcr (GFR calculated by serum Cr, 2009 equation for Cr) and eGFRcys (GFR calculated by serum CysC, 2012 equation for CysC), respectively 7, 16. 60≤GFR<90mL/min/1.73m2wasmild renal function damage, which was defined as CKD Stages 1-2, and GFR<60mL/min/1.73m2 was renal function damage, which was defined as CKD Stages 3-58.
Endothelial function
The endothelial function was evaluated by reactive hyperemia-peripheral arterial tonometry (RHI; Endo-PAT2000; Itamar Medical). And we completed the examination within one week after the onset of stroke. The examination should be conducted in a quiet and appropriate temperature environment. The endothelial mediated changes in vascular tension were quantified by occluding the brachial artery for 5 minutes with standard cuff inflation. When the cuff deflates, the blood flow shocks cause reactive congestion, which can be captured by Endo-PAT in time, and the signal amplitude ratio before and after blocking can be calculated by software to obtain the evaluation index of endothelial function RHI. RHI < 1.67 was considered to indicate ED17.
Assessment of cognitive function
The cognitive function of the patients at baseline and 3 months was evaluated by using the MoCA scale. The evaluation process was conducted by trained neurologists. The total score of MoCA is 30 points, and the lower the score, the more serious of PSCI in patients with MIS. Cognitive function is classified as follows: 27-30 points is defined as no cognitive impairment, and 0-22 points is defined as post-stroke dementia (PSD). In this study, MoCA score ≤26 indicates the presence of PSCI.
Statistical analysis
The continuous variables were expressed as mean±standard deviation (SD), and t-test was performed for independent group comparison. The categorical variables were expressed as count (%), and were analyzed by χ2 test. Correlation analysis between the two variables was conducted using Spearman correlation analysis, and the influencing factors were analyzed by Logistic regression analysis and linear regression. The levels of each index between PSCI and without PSCI groups were compared to find out the influencing factors of PSCI in univariate analysis. Logistic regression analysis was used to identify the independent risk factors for the presence of PSCI within variables with p< 0.05 in the univariate analysis. The receiver operating characteristic (ROC) curve was applied to explore the optimal cutoff value of the independent risk factors levels for predicting PSCI. For all the analyses, P < 0.05 was considered statistically significant. Statistical analyses had been carried out the use of the SPSS program (Version 21.0, IBM Statistics). Results are reported according to the STROBE reporting guidelines (Supplemental Material)18