Characterizing Reasons for Stroke Thrombectomy Ineligibility Among Potential Candidates Transferred in a Hub‐and‐Spoke Network

Abstract

Background Access to endovascular thrombectomy (EVT) is relatively limited. Hub‐and‐spoke networks seek to transfer appropriate large‐vessel occlusion stroke candidates to EVT‐capable hubs. However, some patients are ineligible upon hub arrival, and factors that drive transfer inefficiencies are not well described. We sought to quantify EVT transfer efficiency and identify reasons for EVT ineligibility. Methods Consecutive EVT candidates presenting to 25 spokes from 2018 to 2020 with pretransfer computed tomography angiography‐defined large‐vessel occlusion and Alberta Stroke Program Early Computed Tomography Score of ≥6 were identified from a prospectively maintained database. Outcomes of interest included hub EVT, reasons for EVT ineligibility, and 90‐day modified Rankin scale score of ≤2. Results Among 258 patients, the median age was 70 years (interquartile range, 60–81 years); 50% were women. A total of 56% were ineligible for EVT after hub arrival. Cited reasons were large established infarct (49%), mild symptoms (33%), recanalization (6%), distal occlusion (5%), subocclusive lesion (3%), and goals of care (3%). Late window patients (last known well >6 hours) were more likely to be ineligible (67% versus 43%; P <0.0001). EVT‐ineligible patients were older (73 versus 68 years; P =0.04), had lower National Institutes of Health Stroke Scale score (10 versus 16; P <0.0001), had longer last known well‐to‐hub arrival time (8.4 versus 4.6 hours; P <0.0001), had longer spoke Telestroke consult‐to‐hub arrival time (2.8 versus 2.2 hours; P <0.0001), and received less intravenous thrombolysis (32% versus 45%; P =0.04) compared with eligible patients. EVT ineligibility independently reduced the odds of 90‐day modified Rankin scale score of ≤2 (adjusted odds ratio, 0.26; 95% CI, 0.12–0.56; P =0.001) when controlling for age, National Institutes of Health Stroke Scale score, and last known well‐to‐hub arrival time. Conclusions Among patients transferred for EVT, there are multiple reasons for ineligibility upon hub arrival, with most excluded for infarct growth and mild symptoms. Understanding factors that drive transfer inefficiencies is important to improve EVT access and outcomes.