Supplementary Material for: Efficacy and Safety of Mechanical Thrombectomy in Elderly and Non-Elderly Patients with Large Vessel Occlusion Stroke A Systematic Review and Meta-Analysis

INTRODUCTION Mechanical thrombectomy (MT) is recommended for large vessel occlusion (LVO) stroke. However, most of the studies that investigated the superiority of MT over best medical management (BMM) alone included preponderantly non-elderly patients. Thus, there is uncertainty in relation to the efficacy of MT in the elderly. We aim to compare the effect of BMM to BMM plus (MT) among elderly and non-elderly patients with (LVO). METHODS We performed a systematic search of medical databases from inception to April 2023 to identify randomized studies that reported the functional outcome at 90 days by age for patients with LVO treated with MT vs. BMM. Patients were divided into elderly (>70 or >80 years, depending on the cut-off used in each study) and non-elderly. Outcomes were defined as excellent (modified Rankin Scale [mRS]≤1), good (mRS≤3), poor (mRS≥5), or death. Effect sizes were calculated by using random effects meta-analyses. Results were represented by odds ratio (OR) and their 95% confidence intervals (95% CI). RESULTS A total of 2,195 patients were included in the analysis (≥70 years, 7 trials, n= 696; ≥80 years, 2 trials, n=139). Non-elderly patients treated with MT had higher odds of excellent outcome (OR 3.05; 95% CI 2.23-4.18) and good outcome (OR 2.70; 95% CI 1.94-3.74), and lower odds of poor outcome (OR 0.54; 95% CI 0.40-0.72) and death (OR 0.63; 95% CI 0.41-0.96). Similarly, elderly patients treated with MT had higher odds of excellent (OR 2.39; 95% CI 1.05-5.45) and good outcomes (OR 2.18; 95% CI 1.43-3.33) and lower odds of poor outcome (OR 0.48; 95% CI 0.33-0.70) and mortality (OR 0.50; 0.26-0.95). When outcomes were analyzed by age subgroups, MT was associated with higher odds of good outcome in patients ≥70 years (OR 1.95, 95% CI 1.26-3.03) and ≥80 years (OR 4.43, 95% CI 1.02-19.23). DISCUSSION/CONCLUSION MT increases the likelihood of achieving a good outcome in elderly and non-elderly patients without increasing the risk of severe disability or death. MT, when otherwise clinically indicated, should be considered over BMM alone in both age groups.