Abstract Body: Introduction
Chronic kidney disease (CKD) and ischemic stroke are both associated with significant global disease burdens and share common risk factors. Understanding the impact of CKD on stroke incidence is essential for improving patient outcomes. Traditionally, CKD severity has been graded using the estimated glomerular filtration rate (eGFR). However, the Kidney Failure Risk Equation (KFRE), which incorporates age, sex, eGFR, and the urine albumin/creatinine ratio, has emerged as a more robust tool for predicting progression to end-stage kidney disease. This study aimed to investigate if CKD severity, as assessed by these parameters is associated with incident acute ischemic stroke.

Methods
Consecutive CKD patients receiving care within the National University Health System from March 2022 to September 2023 were included for analyses. Patients with a previous history of ischemic stroke or transient ischemic attack were excluded. CKD severity was defined by eGFR calculated with the CKD-EPI equation and as per KDIGO guidelines. The 2-year and 5-year risk of kidney failure was estimated by the 4-variable KFRE. Cox proportional hazards model was used to study the relationship between CKD stage and KFRE scores with acute ischemic stroke.

Results
A total of 14,794 consecutive CKD patients were included, of which 155 (1.05%) experienced an acute ischemic stroke. The median age was 73 years old (IQR = 14), with 6,251 females (42.3%) and the majority being Chinese (n = 10,759; 73.5%). The median days-to-stroke was 265 days (IQR 242 days). Older age (p<0.001), ischemic heart disease (p<0.001), advanced CKD Stage 4-5 (p=0.013) and KFRE strata (p=0.0018) were associated with ischemic stroke. The risk of ischemic stroke was higher with advanced CKD stage; CKD Stage 4-5 patients were more likely to develop an acute ischemic stroke event as compared to CKD Stage 1-3b patients (HR 1.70, 95%CI: 1.14-2.53). Moreover, a 10% increase in 2-year and 5-year kidney failure risks corresponded to significantly higher risks of ischemic stroke, with hazard ratios of 1.38 (95% CI: 1.17-1.63) and 1.20 (95% CI: 1.10-1.31), respectively. These associations remained significant after adjusting for age, gender, ethnicity, comorbidities, HbA1c and lipid parameters.

Conclusion
CKD patients at elevated risk of kidney failure also face an increased risk of suffering an acute ischemic stroke. Implementing the KFRE in CKD management could prove valuable in assessing ischemic stroke risk.