Influence of Age on Outcomes of Endovascular Treatment in Posterior versus Anterior Circulation Stroke: A Comparative Analysis in a Nationwide Registry

<b><i>Introduction:</i></b> It is unknown whether the influence of age on clinical outcomes post endovascular treatment (EVT) is similar in posterior circulation stroke (PCS) compared to anterior circulation stroke (ACS). <b><i>Methods:</i></b> Data were extracted from the ETIS registry, a nationwide prospective, multicenter, observational registry for stroke EVT procedures in France. We included patients treated with EVT for PCS or ACS between January 2015 and August 2023. The relationship between patient age and clinical outcome variables was studied using regression analysis. Good clinical outcome was defined as modified Rankin scale score ≤2 at 90 days. <b><i>Results:</i></b> The study included 935 patients with PCS and 11,427 patients with ACS. There were no significant differences between PCS and ACS in the influence of age on the likelihood of good clinical outcome. The influence of age on the likelihood of mortality was significantly different. Mortality was higher for PCS between 30 and 85 years, without significant differences in younger or older patients. Elderly patients (≥80 years) with PCS had similar rates of good clinical outcome and mortality compared to patients with ACS from the same age group. <b><i>Conclusion:</i></b> In this comparative analysis assessing the impact of age on EVT outcomes in posterior versus anterior circulation stroke, differences were observed in middle-aged patients, whereas outcomes tended to converge in young and elderly age groups. Elderly PCS patients had similar outcomes as ACS patients from the same age group.