312 Mechanical Thrombectomy With or Without Intravenous Thrombolysis for Acute Ischemic Stroke Due to Distal and Medium Vessel Occlusions: A Propensity Score Matching of Patients From 41 Academic Centers

INTRODUCTION: To date, studies evaluating mechanical thrombectomy (MT) in distal and medium vessel occlusions (DMVOs) have failed to establish conclusive, high-quality evidence for its clinical benefit. METHODS: Between January 2017 and January 2022, characteristics and outcomes of patients with DMVOs treated with MT or MT + IVtPA were collected at 41 academic centers in North America, Asia, and Europe. Using R software version 4.2.3, propensity score matching using the nearest neighbor matching by controlling for all relevant variables, followed by appropriate descriptive statistics and multivariate logistic regression. RESULTS: After propensity score matching, all differences between groups were resolved, and there was a total of 577 patients included (315 MT alone and 262 MT +IVT). Patients treated with MT + IVT achieved greater rates of TICI 2b-3 (OR = 1.79, 95% CI = 1.02-3.15; P-value= 0.043) than those treated with MT alone, and the rate of modified Rankin score (mRS) 0-2 was greater in the MT + IVT group (n = 171, 65.3%) compared to the MT alone (n = 181, 57.5%) group (OR = 1.52, 95% CI= 1.03-2.24; p-value = 0.034). Sixty-nine patients experienced 90-day mortality, and the rate was comparable between the MT + IVtPA group (n = 30, 11.5%) and the MT alone (n = 39, 12.4%) group (OR = 0.9, 95% CI = 0.53-1.54; p-value = 0.71). Of note, the rate of intracranial hemorrhage (all types) was similar between the MT + IVtPA and MT alone group (OR = 0.85, 95% CI = 0.58-1.26; p-value = 0.43). CONCLUSIONS: MT + IVT showed higher efficacy than MT alone in patients with DMVOs, without higher risks.