Abstract Number ‐ 53: Endovascular therapy versus medical management for mild strokes due to medium and distal vessel occlusions

Distal and medium vessel occlusion (DMVO) strokes account for 25–40% of all acute ischemic strokes1 and are associated with long‐term disability in as many as 77% of patients2. Approximately one third of DMVO stroke patients have a low National Institute of Stroke Scale (NIHSS) (≤6)3. Multiple randomized controlled trials showed superiority of endovascular therapy (EVT) over best medical management (BMT) in patients presenting with proximal LVO involving the anterior circulation and NIHSS of >64. The efficacy and safety of EVT for DMVO patients is uncertain, especially in patients with low NIHSS. A better understanding of this issue is important because many patients with DMVO and low NIHSS scores suffer disabling deficits while procedural risk are increased due to the target vessels’ small caliber, tortuosity, and thinner walls. We conducted a retrospective single center study to compare clinical and safety outcomes of DMVO patients with NIHSS ≤ 6 that were treated with EVT versus BMT. We retrospectively analyzed consecutive patients with acute mild (NIHSS ≤ 6) DMVO stroke that presented between January 2018 and December 2021. We defined DMVO stroke as stroke caused by an occlusion of the M2‐4 segments of the MCA, A2‐3 segments of the ACA, P1‐2 segments of the PCA. Outcomes of interest were the NIHSS at day one and at discharge, the change in NIHSS from admission to discharge (ΔNIHSS) and the mRS at 90‐days. Safety outcomes were clinical deterioration, defined as an increase in the NIHSS by 4 or more points and the occurrence of symptomatic intracranial hemorrhage (sICH), defined as any type of ICH causing an increase in the NIHSS by 4 or more points. Overall, we included 80 subjects that fulfilled our study criteria. Of these, 41 were treated with BMT and 39 were selected to undergo EVT. Clinical characteristics of subjects selected for BMT versus EVT were overall similar except for more frequent diabetes (p = 0.035) and antiplatelet use (p = 0.045) as well as less frequent anticoagulation (p = 0.019) in the BMT group. Moreover, subjects selected for EVT had a lower pre‐stroke mRS (p = 0.025) and a lower ASPECT score on the admission head CT (p = 0.044). Overall, there was no statistical difference between NIHSS at day 1 (p = 0.654), NIHSS at discharge (p = 0.244), and ΔNIHSS from Day 0 to Day 1 (p = 0.08). There was further no difference in the discharge (p = 0.895) and 3‐month (p = 0.957) mRS between groups. Regarding safety outcomes, there was no difference in the number of all types of ICHs combined between the two groups (p = 0.229) and there was no difference in the number of patients who had clinical deterioration (p = 0.258). Our analysis shows that in patients who present with mild DMVO strokes, early and 3‐month clinical outcomes were comparable between EVT and BMT groups. Moreover, risk of intracranial hemorrhage, clinical deterioration, and death were similar between groups. Nevertheless, given the low number of subjects, our analysis did not reach statistical significance and further large‐scale studies are required to clarify efficacy and safety of EVT versus BMT in DMVO patients with low clinical deficit severity