IntroductionAging population leads to changes in the profile of patients with acute ischemic stroke (IS), and older adults were largely excluded from randomized clinical trials of acute revascularization therapy. This study aimed to assess functional outcomes of treated IS patients > 80 years old according to prior disability and identify associated factors.MethodsConsecutively older patients with acute IS treated with either IV thrombolysis and/or mechanical thrombectomy were enrolled between 2016 and 2019. Pre-morbid disability was assessed using the modified Rankin Scale (mRS) score, and patients were classified as being independent (mRS score, 0–2) or having pre-existing disability (mRS score, 3–5). A multivariable logistic regression analysis was performed to assess factors associated with a poor functional outcome (mRS score > 3) at 3 and 12 months in each group of patients.ResultsAmong 300 included patients (mean age: 86.3 ± 4.6 years, 63% women, median NIHSS score: 14, IQR: 8–19), 100 had a pre-existing disability. In patients with a pre-morbid mRS score of 0–2, 51% had mRS >3 including 33% of deaths at 3 months. At 12 months, 50% had a poor outcome including 39% of deaths. In patients with a pre-morbid mRS score of 3–5, 71% had a poor outcome at 3 months including 43% of deaths, and at 12 months, 76% had mRS >3 including 52% of deaths. In multivariable models, the NIHSS score at 24 h was independently associated with poor outcomes at 3 and 12 months in both patients with (OR = 1.32; 95% CI: 1.16–1.51,p< 0.001 for 12 months outcome) or without (OR = 1.31; 95% CI: 1.19–1.44,p< 0.001 for 12 months outcome) pre-morbid disability.ConclusionAlthough a large proportion of older patients with a pre-existing disability had a poor functional outcome, they did not differ from their non-impaired counterparts regarding prognostic factors. This means that there were no factors in our study that would help clinicians identify patients at risk of poor functional outcomes after revascularization therapy among those with prior disability. Further studies are needed to better understand the post-stroke trajectory of older IS patients with a pre-morbid disability.