From arteries to age: an intrinsic impact of Circle of Willis on first-ever acute ischemic stroke in the oldest-old

Background: This study aimed to describe the characteristics of CoW configuration in the oldest-old patients with first-ever acute ischemic stroke, and investigate the association of CoW with the first-onset age of acute ischemic stroke in the elderly population. Methods: The patients with first-ever acute ischemic stroke were consecutively enrolled between March 2022 and June 2024. All patients underwent MRA or CTA of brain. According to their first-onset age, they were divided into two groups (oldest-old group, aged ≥80 years; elderly group, aged 60-79 years). Demographic and clinical data were collected, and CoW scores and types were independently assessed by two experienced neurologists. Results: The oldest-old group showed greater Anterior communicating artery (AcoA) and total CoW scores and a higher ratio of complete CoW as compared with the elderly group. Poor CoW was associated with earlier first-onset age, and higher AcoA score was associated with later first-onset age, even after adjustments by conventional risk factors. In the female cohort, the oldest-old subset showed high scores of AcoA, Posterior communicating artery (PcoA) and total CoW, with all difference strength significantly greater than those in all subjects. Additionally, in the female cohort, first-onset age was significantly related with AcoA score, total CoW score and poor CoW, whether non-adjusted or adjusted. Conclusions: The oldest-old patients with first-onset ischemic stroke have a higher CoW score and better morphology than the elderly patients, with females more significant. Females with poor CoW should be recommended for risk stratification of ischemic stroke to generate more effective and precise strategies for stroke prevention and healthy aging.