BackgroundRecent studies have demonstrated the superiority of endovascular therapy (EVT) for emergent large vessel occlusion.ObjectiveTo determine the effectiveness of EVT in nonagenarians, for whom data are limited.MethodsWe retrospectively reviewed clinical and imaging data of all patients who underwent EVT at two stroke centers between January 2012 and August 2014. The 90-day functional outcome (modified Rankin Scale (mRS) score) was compared between younger patients (age 18–89 years; n=175) and nonagenarians (n=18). The relationship between pre-stroke and 90-day post-stroke mRS was analyzed in these two groups. Multivariable analysis of age, recanalization grade, and admission National Institutes of Health Stroke Scale (NIHSS) for predicting outcome was performed.ResultsAge ≥90 years was associated with a poor (mRS >2) 90-day outcome relative to those under 90 (89% vs 52%, OR=8, 95% CI 1.7 to 35.0; p=0.0081). Nonagenarians had a higher pre-stroke mRS score (0.77; 95% CI 0.44 to 1.30) than younger patients (0.24; 95% CI 0.17 to 0.35; p=0.005). No difference was observed between nonagenarians and younger patients in the rate of mRS change from pre-stroke to 90 days (p=0.540). On multivariable regression, age (OR=1.05, 95% CI 1.03 to 1.08; p<0.0001), recanalization grade (OR=0.62 95% CI 0.42 to 0.91; p=0.015), and admission NIHSS (OR=1.07 95% CI 1.02 to 1.13; p=0.01) were associated with a poor 90-day outcome.ConclusionsNonagenarians are at a substantially higher risk of a poor 90-day outcome after EVT than younger patients. However, a small subset of nonagenarians may benefit from EVT, particularly if they have a good pre-stroke functional status. Further research is needed to identify factors associated with favorable outcome in this age cohort.