Outcome Following Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke in the Elderly

Background: Pooled data of randomized controlled trials investigating mechanical thrombectomy (MT) to treat anterior circulation large vessel occlusion have demonstrated safety and effectiveness across all age groups, including ≥ 80 years of age; however, only a few nonagenarians were in the ≥ 80 years subgroup. Therefore, the benefit of MT in nonagenarians is mostly unknown. Methods: Two comprehensive stroke centers retrospectively reviewed all acute ischemic stroke patients who underwent MT for anterior circulation large vessel occlusion (LVO) stroke between February 2016 and August 2020. Revascularization TICI2b/3, symptomatic intracranial hemorrhage (ICH), and functional outcome using modified Rankin scale (mRS) were assessed for cases aged < 80 years, 80–89 years, and 90–99 years. Favorable functional outcome was defined as mRS 0–2 or reaching the prestroke mRS and moderate as mRS 0–3. Results: The final data set comprised a total of 736 cases. Of these, 466 aged < 80 years, 219 aged 80–89 years, and 51 aged 90–99 years. In nonagenarians, TICI 2b/3 revascularization was observed in 84.3% while symptomatic ICH was observed in 4%. These rates were similar to 80–89 years and < 80 years age groups. Favorable and moderate functional outcome as well as death rates differed significantly between nonagenarians and < 80 years (19.6%, 29.4%, 51.0% vs 47.9%, 60.7%, 18.7%, respectively, p < 0.001), but were similar between nonagenarians and octogenarians (29.7%, 38.8%, 38.8%, p = 0.112–0.211). Conclusion: A moderate outcome among nonagenarians was observed in about 30%, while mortality rates were about 50%. Withholding mechanical thrombectomy does not appear justifiable, although the absolute treatment effect among nonagenarians remains unknown.