Age-specific associations of endovascular therapy and reperfusion delay with outcomes after large vessel occlusion: a regional registry study

INTRODUCTION: The benefit of endovascular therapy (EVT) in very elderly patients with large vessel occlusion (LVO) remains uncertain, and sensitivity to reperfusion delay may differ by age. We evaluated age-specific associations of treatment and reperfusion time with functional outcomes. PATIENTS AND METHODS: We analysed 1,280 patients with acute LVO in an emergency medical service-based registry, divided into groups aged 85 years or older and younger than 85 years. The primary outcome was an ordinal shift towards a better 90-day modified Rankin Scale (mRS) score. Secondary outcomes were dichotomized functional measures incorporating prestroke status. RESULTS: Among 837 patients younger than 85 years, EVT was associated with a favourable mRS shift (adjusted odds ratio [aOR], 1.47; 95% confidence interval [CI], 1.07-2.01). Among 443 patients aged 85 years or older, the estimate was favourable but not statistically significant (aOR, 1.29; 95% CI, 0.87-1.92). No significant age-by-treatment interaction was observed for functional outcomes. Among patients treated with successful reperfusion by EVT, favourable outcomes declined more steeply with increasing onset-to-reperfusion time in those aged 85 years or older. DISCUSSION: The association of EVT with functional outcomes was not significantly modified by age but estimates in very elderly patients were less precise. Very elderly patients appeared more vulnerable to reperfusion delay. CONCLUSION: Treatment selection should integrate prestroke function, stroke severity, imaging findings, procedural feasibility, and the likelihood of rapid reperfusion rather than age alone.