Cytoprotective agents in stroke: Still uncertainty in the next frontier.

INTRODUCTION: Despite substantial improvement of acute ischemic stroke (AIS) care with the advent of extended time windows for intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT), a substantial portion of patients still suffer poor outcomes. Additional adjuvant therapies are needed but pharmacologic interactions among therapies may dictate how they could be used. We conducted a survey to determine physician decision-making regarding the use of cytoprotective agents in patients presenting with AIS. METHODS: The survey was structured, web-based, anonymous, and invite-only among physicians across the world treating patients presenting with AIS. Respondents were asked about the use of a hypothetical cytoprotective agent (that provided an added 10% benefit) in the context of a treatment interaction with IVT or its timing in relation to IVT. RESULTS: A total of 282 stroke physicians (74.9% males, mean age 46 years) participated in the survey. When the respondent could give both the cytoprotective agent and IVT with no treatment interaction, 177 (78.0%) chose to administer both. In the presence of treatment interaction, 88 (38.3%) would withhold IVT, 83 (36.1%) would withhold the cytoprotective agent and 56 (24.4%) were uncertain. Lastly, 111 (48.9%) were willing to administer the cytoprotective agent if it meant a necessary 10-minute delay in IVT administration. CONCLUSIONS: Pharmacologic interactions result in major uncertainty about cytoprotective treatment choices.

Worldwide Survey on Approach to Thrombolysis in Acute Ischemic Stroke With Large Vessel Occlusion.

Background and Objectives: With recent trials suggesting that endovascular thrombectomy (EVT) alone may be noninferior to combined intravenous thrombolysis (IVT) with alteplase and EVT and that tenecteplase is non-inferior to alteplase in treating acute ischemic stroke, we sought to understand current practices around the world for treating acute ischemic stroke with large vessel occlusion (LVO) depending on the center of practice (IVT-capable vs IVT and EVT-capable stroke center). Methods: The electronic survey launched by the Practice Current section of Neurology: Clinical Practice included 6 clinical and 8 demographic questions. A single-case scenario was presented of a 65-year-old man presenting with right hemiplegia with aphasia with a duration of 1 hour. Imaging showed left M1-MCA occlusion with no early ischemic changes. The respondents were asked about their treatment approach in 2 settings: the patient presented to (1) the IVT-only capable center and (2) the IVT and EVT-capable center. They were also asked about the thrombolytic agent of choice in current and ideal circumstances for these settings. Results: A total of 203 physicians (42.9% vascular neurologists) from 44 countries completed the survey. Most participants (55.2%) spent ≥50% of their time delivering stroke care. The survey results showed that in current practice, more than 90% of respondents would offer IVT + EVT to patients with LVO stroke presenting to either an EVT-capable (91.1%) or IVT-only-capable center (93.6%). Although nearly 80% currently use alteplase for thrombolysis, around 60% would ideally like to switch to tenecteplase independent of the practice setting. These results were similar between stroke and non-stroke neurologists. Discussion: Most physicians prefer IVT before EVT in patients with acute ischemic stroke attributable to large vessel occlusion independent of the practice setting.

Association between CT Perfusion Parameters and Hemorrhagic Transformation after Endovascular Treatment in Acute Ischemic Stroke: Results from the ESCAPE-NA1 Trial.

BACKGROUND AND PURPOSE: Hemorrhagic transformation can occur as a complication of endovascular treatment for acute ischemic stroke. This study aimed to determine whether ischemia depth as measured by admission CTP metrics can predict the development of hemorrhagic transformation at 24 hours. MATERIALS AND METHODS: Patients with baseline CTP and 24-hour follow-up imaging from the ESCAPE-NA1 trial were included. RAPID software was used to generate CTP volume maps for relative CBF, CBV, and time-to-maximum at different thresholds. Hemorrhage on 24-hour imaging was classified according to the Heidelberg system, and volumes were calculated. Univariable and multivariable regression analyses assessed the association between CTP lesion volumes and hemorrhage/hemorrhage subtypes. RESULTS: Among 408 patients with baseline CTP, 142 (35%) had hemorrhagic transformation at 24-hour follow-up, with 89 (63%) classified as hemorrhagic infarction (HI1/HI2), and 53 (37%), as parenchymal hematoma (PH1/PH2). Patients with HI or PH had larger volumes of low relative CBF and CBV at each threshold compared with those without hemorrhage. After we adjustied for baseline and treatment variables, only increased relative CBF <30% lesion volume was associated with any hemorrhage (adjusted OR, 1.14; 95% CI, 1.02-1.27 per 10 mL), as well as parenchymal hematoma (adjusted OR, 1.23; 95% CI, 1.06-1.43 per 10 mL). No significant associations were observed for hemorrhagic infarction. CONCLUSIONS: Larger "core" volumes of relative CBF <30% were associated with an increased risk of PH following endovascular treatment. This particular metric, in conjunction with other clinical and imaging variables, may, therefore, help estimate the risk of post-endovascular treatment hemorrhagic complications.

Clinical uncertainty in large vessel occlusion ischemic stroke: does automated perfusion imaging make a difference? An intra-rater and inter-rater agreement study.

BACKGROUND: Limited research exists regarding the impact of neuroimaging on endovascular thrombectomy (EVT) decisions for late-window cases of large vessel occlusion (LVO) stroke. OBJECTIVE: T0 assess whether perfusion CT imaging: (1) alters the proportion of recommendations for EVT, and (2) enhances the reliability of EVT decision-making compared with non-contrast CT and CT angiography. METHODS: We conducted a survey using 30 patients drawn from an institutional database of 3144 acute stroke cases. These were presented to 29 Canadian physicians with and without perfusion imaging. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κG). RESULTS: The percentage of EVT recommendations differed by 1.1% with or without perfusion imaging. Individual decisions changed in 21.4% of cases (11.3% against EVT and 10.1% in favor). Inter-rater agreement (κG) among the 29 raters was similar between non-perfusion and perfusion CT neuroimaging (κG=0.487; 95% CI 0.327 to 0.647 and κG=0.552; 95% CI 0.430 to 0.675). The 95% CIs overlapped with moderate agreement in both. Intra-rater agreement exhibited overlapping 95% CIs for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of raters in both groups. CONCLUSIONS: Despite the minimal difference in overall EVT recommendations with either neuroimaging protocol one in five decisions changed with perfusion imaging. Regarding agreement we found that the use of automated CT perfusion images does not significantly impact the reliability of EVT decisions for patients with late-window LVO.

Prevalence of "Ghost Infarct Core" after Endovascular Thrombectomy.

BACKGROUND AND PURPOSE: Baseline CTP sometimes overestimates the size of the infarct core ("ghost core" phenomenon). We investigated how often CTP overestimates infarct core compared with 24-hour imaging, and aimed to characterize the patient subgroup in whom a ghost core is most likely to occur. MATERIALS AND METHODS: Data are from the randomized controlled ESCAPE-NA1 trial, in which patients with acute ischemic stroke undergoing endovascular treatment were randomized to intravenous nerinetide or placebo. Patients with available baseline CTP and 24-hour follow-up imaging were included in the analysis. Ghost infarct core was defined as CTP core volume minus 24-hour infarct volume > 10 mL). Clinical characteristics of patients with versus without ghost core were compared. Associations of ghost core and clinical characteristics were assessed by using multivariable logistic regression. RESULTS: A total of 421 of 1105 patients (38.1%) were included in the analysis. Forty-seven (11.2%) had a ghost core > 10 mL, with a median ghost infarct volume of 13.4 mL (interquartile range 7.6-26.8). Young patient age, complete recanalization, short last known well to CT times, and possibly male sex were associated with ghost infarct core. CONCLUSIONS: CTP ghost core occurred in ∼1 of 10 patients, indicating that CTP frequently overestimates the infarct core size at baseline, particularly in young patients with complete recanalization and short ischemia duration.

Effect of Needle-To-Puncture Time on Reperfusion Outcome in Acute Ischemic Stroke.

INTRODUCTION: The aim of the study was to investigate the impact of time interval between start of intravenous thrombolysis (IVT) to start of endovascular thrombectomy (EVT) on stroke outcomes. METHODS: Data from the Quality Improvement and Clinical Research (QuICR) provincial stroke registry from Alberta, Canada, were used to identify stroke patients who received IVT and EVT from January 2015 to December 2019. We assessed the impact of the time interval between IVT bolus to EVT puncture (needle-to-puncture times [NPT]) on outcomes. Radiological outcomes included successful initial recanalization (revised Arterial Occlusive Lesion 2b-3), successful initial and final reperfusion (modified thrombolysis in cerebral infarction 2b-3). Clinical outcomes were 90-day modified Rankin Scale (mRS) and mortality. RESULTS: Of the 680 patients, 233 patients (median age: 73, 41% females) received IVT + EVT. Median NPT was 38 min (IQR, 24-60). Arrival during working hours was independently associated with shorter NPT (p < 0.001). Successful initial recanalization and initial and final reperfusion were observed in 12%, 10%, and 83% of patients, respectively. NPT was not associated with initial successful recanalization (OR 0.97 for every 10-min increase of NPT, 95% CI: 0.91-1.04), initial successful reperfusion (OR 1.01, 95% CI: 0.96-1.07), or final successful reperfusion (OR: 1.03, 95% CI: 0.97-1.08). Every 10-min delay in NPT was associated with lower odds of functional independence at 90 days (mRS ≤2; OR: 0.93; 95% CI, 0.88-0.97). Patients with shorter NPT (≤38 min) had lower 90-day mRS scores (median 1 vs. 3; OR: 0.54 [0.31-0.91]) and had lower mortality (6.1% vs. 21.2%; OR, 0.23 [0.10-0.57]) than the longer NPT group. CONCLUSION: Shorter NPT did not impact reperfusion outcomes but was associated with better clinical outcome.

No Sex Differences in Mechanical Thrombectomy Time Metrics and Outcomes in Saskatchewan.

BACKGROUND AND PURPOSE: Numerous studies have shown longer pre-hospital and in-hospital workflow times and poorer outcomes in women after acute ischemic stroke (AIS) in general and after endovascular treatment (EVT) in particular. We investigated sex differences in acute stroke care of EVT patients over 5 years in a comprehensive Canadian provincial registry. METHODS: Clinical data of all AIS patients who underwent EVT between January 2017 and December 2022 in the province of Saskatchewan were captured in the Canadian OPTIMISE registry and supplemented with patient data from administrative data sources. Patient baseline characteristics, transport time metrics, and technical EVT outcomes between female and male EVT patients were compared. RESULTS: Three-hundred-three patients underwent EVT between 2017 and 2022: 144 (47.5%) women and 159 (52.5%) men. Women were significantly older (median age 77.5 [interquartile range: 66-85] vs.71 [59-78], p < 0.001), while men had more intracranial internal carotid artery occlusions (48/159 [30.2%] vs. 26/142 [18.3%], p = 0.03). Last-known-well to comprehensive stroke center (CSC)-arrival time (median 232 min [interquartile range 90-432] in women vs. 230 min [90-352] in men), CSC-arrival-to-reperfusion time (median 108 min [88-149] in women vs. 102 min [77-141] in men), reperfusion status (successful reperfusion 106/142 [74.7%] in women vs. 117/158 [74.1%] in men) as well as modified Rankin score at 90 days did not differ significantly. This held true after adjusting for baseline variables in multivariable analyses. CONCLUSION: While women undergoing EVT in the province of Saskatchewan were on average older than men, they were treated just as fast and achieved similar technical and clinical outcomes compared to men.

Stroke metrics during the first year of the COVID-19 pandemic, a tale of two comprehensive stroke centers.

Although a decrease in stroke admissions during the SARS-CoV-2 pandemic has been observed, detailed analyses of the evolution of stroke metrics during the pandemic are lacking. We analyzed changes in stroke presentation, in-hospital systems-of-care, and treatment time metrics at two representative Comprehensive Stroke Centers (CSCs) during the first year of Coronavirus disease 2019 pandemic. From January 2018 to May 2021, data from stroke presentations to two CSCs were obtained. The study duration was split into: period 0 (prepandemic), period 1 (Wave 1), period 2 (Lull), and period 3 (Wave 2). Acute stroke therapies rates and workflow times were compared among pandemic and prepandemic periods. Analyses were adjusted for age, sex, comorbidities, and pre-morbid care needs. There was a significant decrease in monthly hospital presentations of stroke during Wave 1. Both centers reported declines in reperfusion therapies during Wave 1, slowly catching up but never to pre pandemic numbers, and dropping again in Wave 2. Both CSCs experienced in-hospital workflow delays during Waves 1 and 2, and even during the Lull period. Our results highlight the need for proactive strategies to reduce barriers to workflow and hospital avoidance for stroke patients during crisis periods.

Influence of geography, stroke timing, and weather conditions on transport and workflow times: Results from a longitudinal 5-year Canadian provincial registry.

BACKGROUND: In areas with high population spread such as Saskatchewan, it can be challenging to provide timely endovascular stroke treatment (EVT) to patients living far away from comprehensive stroke centres (CSC). We assessed the association of geography, stroke timing and weather conditions on EVT workflow times and clinical outcomes in Saskatchewan. METHODS: We included patients who underwent EVT between January 2017 and December 2022 in the province of Saskatchewan, Canada. Univariable and multivariable associations of time from last known well-to-CSC arrival, CSC arrival-to-reperfusion, and 90-day modified Rankin Score (mRS) with driving distance from patient home to CSC, transport mode, outdoor temperature and stroke timing (day & time) were assessed using descriptive statistics and multivariable regression. RESULTS: Three-hundred-three patients in the province of Saskatchewan underwent EVT between January 2017 and December 2022. Distance from patient home to CSC (beta-coefficient per 10 km increase = 0.02, 95% CI: 0.01-0.03) and direct to CSC transport (beta-coefficient = -0.76, 95% CI = -1.01-[-0.51]) were associated with last known well to CSC arrival time. In-hospital stroke (beta-coefficient = 0.37, 95% CI: 0.16-0.58), direct-to-CSC transfer (beta-coefficient = 0.27, 95% CI: 0.13-0.41) and daytime stroke onset (beta-coefficient = -0.15, 95% CI: -0.28-[-0.04]) were associated with time from CSC arrival to reperfusion. No association with 90-day mRS was seen. CONCLUSION: Geographic factors and stroke timing were associated with EVT workflow times. However, no association with clinical outcomes was seen, suggesting that EVT patients living remote areas of Saskatchewan have similar benefit from EVT compared to urban areas. Every effort should be made to offer timely EVT to patients from remote areas.

Endovascular therapy in acute ischemic stroke with poor reperfusion is associated with worse outcomes compared with best medical management: a HERMES substudy.

BACKGROUND: Functional outcomes in patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO) undergoing endovascular treatment (EVT) with poor reperfusion were compared with patients with AIS-LVO treated with best medical management only. METHODS: Data are from the HERMES collaboration, a patient-level meta-analysis of seven randomized EVT trials. Baseline characteristics and functional outcomes (modified Rankin Scale (mRS) score at 90 days) were compared between patients with poor reperfusion (defined as modified Thrombolysis in Cerebral Infarction Score 0-1 on the final intracranial angiography run as assessed by the central imaging core laboratory) and patients in the control arm with multivariable logistic ordinal logistic regression adjusted for pre-specified baseline variables. RESULTS: 972 of 1764 patients from the HERMES collaboration were included in the analysis: 893 in the control arm and 79 in the EVT arm with final mTICI 0-1. Patients with poor reperfusion who underwent EVT had higher baseline National Institutes of Health Stroke Scale than controls (median 19 (IQR 15.5-21) vs 17 (13-21), P=0.011). They also had worse mRS at 90 days compared with those in the control arm in adjusted analysis (median 4 (IQR 3-6) vs median 4 (IQR 2-5), adjusted common OR 0.59 (95% CI 0.38 to 0.91)). Symptomatic intracranial hemorrhage was not different between the two groups (3.9% vs 3.5%, P=0.75, adjusted OR 0.94 (95% CI 0.23 to 3.88)). CONCLUSION: Poor reperfusion after EVT was associated with worse outcomes than best medical management, although no difference in symptomatic intracranial hemorrhage was seen. These results emphasize the need for additional efforts to further improve technical EVT success rates.

Effect of incomplete reperfusion patterns on clinical outcome: insights from the ESCAPE-NA1 trial.

BACKGROUND: Incomplete reperfusion (IR) after mechanical thrombectomy (MT) can be a consequence of residual occlusion, no-reflow phenomenon, or collateral counterpressure. Data on the impact of these phenomena on clinical outcome are limited. METHODS: Patients from the ESCAPE-NA1 trial with IR (expanded Thrombolysis In Cerebral Infarction (eTICI) 2b) were compared with those with complete or near-complete reperfusion (eTICI 2c-3) on the final angiography run. Final runs were assessed for (a) an MT-accessible occlusion, or (b) a non-MT-accessible occlusion pattern. The primary clinical outcome was modified Rankin Scale (mRS) 0-2 at 90 days. Our imaging outcome was infarction in IR territory on follow-up imaging. Unadjusted and adjusted incidence rate ratios (aIRR) with 95% confidence intervals (95% CI) were obtained. RESULTS: Of 1105 patients, 443 (40.1%) with IR and 506 (46.1%) with complete or near-complete reperfusion were included. An MT-accessible occlusion was identified in 147/443 patients (33.2%) and a non-MT-accessible occlusion in 296/443 (66.8%). As compared with patients with near-complete/complete reperfusion, patients with IR had significantly lower chances of achieving mRS 0-2 at 90 days (aIRR 0.82, 95% CI 0.74 to 0.91). Rates of mRS 0-2 were lower in the MT-accessible occlusion group as compared with the non-MT-accessible occlusion pattern group (aIRR 0.71, 95% CI 0.60 to 0.83, and aIRR 0.89, 95% CI 0.81 to 0.98, respectively). More patients with MT-accessible occlusion patterns developed infarcts in the non-reperfused territory as compared with patients with non-MT occlusion patterns (68.7% vs 46.3%). CONCLUSION: IR was associated with worse clinical outcomes than near-complete/complete reperfusion. Two-thirds of our patients with IR had non-MT-accessible occlusion patterns which were associated with better clinical and imaging outcomes compared with those with MT-accessible occlusion patterns.

Infarcts in a New Territory: Insights From the ESCAPE-NA1 Trial.

BACKGROUND: Infarct in a new territory (INT) is a known complication of endovascular stroke therapy. We assessed the incidence of INT, outcomes after INT, and the impact of concurrent treatments with intravenous thrombolysis and nerinetide. METHODS: Data are from ESCAPE-NA1 trial (Safety and Efficacy of Nerinetide [NA-1] in Subjects Undergoing Endovascular Thrombectomy for Stroke), a multicenter, international randomized study that assessed the efficacy of intravenous nerinetide in subjects with acute ischemic stroke who underwent endovascular thrombectomy within 12 hours from onset. Concurrent treatment and outcomes were collected as part of the trial protocol. INTs were identified on core lab imaging review of follow-up brain imaging and defined by the presence of infarct in a new vascular territory, outside the baseline target occlusion(s) on follow-up brain imaging (computed tomography or magnetic resonance imaging). INTs were classified by maximum diameter (<2, 2-20, and >20 mm), number, and location. The association between INT and clinical outcomes (modified Rankin Scale and death) was assessed using standard descriptive techniques and adjusted estimates of effect were derived from Poisson regression models. RESULTS: Among 1092 patients, 103 had INT (9.3%, median age 69.5 years, 49.5% females). There were no differences in baseline characteristics between those with versus without INT. Most INTs (91/103, 88.3%) were not associated with visible occlusions on angiography and 39 out of 103 (37.8%) were >20 mm in maximal diameter. The most common INT territory was the anterior cerebral artery (27.8%). Almost half of the INTs were multiple (46 subjects, 43.5%, range, 2-12). INT was associated with poorer outcomes as compared to no INT on the primary outcome of modified Rankin Scale score of 0 to 2 at 90 days (adjusted risk ratio, 0.71 [95% CI, 0.57-0.89]). Infarct volume in those with INT was greater by a median of 21 cc compared with those without, and there was a greater risk of death as compared to patients with no INT (adjusted risk ratio, 2.15 [95% CI, 1.48-3.13]). CONCLUSIONS: Infarcts in a new territory are common in individuals undergoing endovascular thrombectomy for acute ischemic stroke and are associated with poorer outcomes. Optimal therapeutic approaches, including technical strategies, to reduce INT represent a new target for incremental quality improvement of endovascular thrombectomy. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02930018.

Challenges and opportunities in research funding for neurovascular diseases from a clinical researcher's perspective.

BACKGROUND & PURPOSE: Neurovascular research is underfunded, imposing substantial challenges on clinical researchers in the field of neurovascular diseases. We explored what physicians perceive to be the greatest challenges with regard to neurovascular research funding, and how they think the funding crisis in neurovascular research could be overcome. METHODS: We performed an international, multi-disciplinary survey among physicians involved in the medical care of patients with neurovascular diseases. After providing their demographic data, physicians were asked closed-ended questions on their personal opinion regarding challenges in neurovascular research funding, and how these challenges could be overcome. Physicians also described in their own words what they perceived to be the biggest challenges in obtaining funding. Data were analyzed using descriptive statistics and response clustering. RESULTS: Of 233 participating physicians (70.4% male,82.8% senior staff) from 48 countries, 217(97.4%) perceived the discrepancy between required and available funding to be a problem;172(73.8%) considered it a major problem. High competitiveness (61/118 available free text responses[51.7%]), time-consuming application processes (28/118[23.7%]) and administrative requirements (25/118[21.1%]) were identified as key obstacles. Traditional big funding agencies were perceived to be most capable of closing the neurovascular research funding gap, followed by specialty-specific organizations and industry, while philanthropy and crowdfunding were perceived to be less important. CONCLUSION: The gap between required and available funding was perceived to be a major problem in neurovascular research, with high competitiveness, time-consuming funding processes and excessive administrative requirements being the key obstacles to obtaining funding. Traditional funding agencies were perceived to be most capable of closing this funding gap.

Desired Qualities of Endovascular Tools and Barriers to Treating Medium Vessel Occlusion MeVO : Insights from the MeVO-FRONTIERS International Survey.

BACKGROUND: Endovascular treatment (EVT) for stroke due to medium vessel occlusion (MeVO) can be technically challenging and specific endovascular tools are needed to safely and effectively recanalize these relatively small and fragile vessels. We aimed to gain insight into availability and desired qualities of endovascular devices used in MeVO stroke and examined barriers to adoption of MeVO EVT in clinical practice on a global scale. METHODS: We conducted a case-based international survey among neurointerventionalists. As a part of the survey, participants were asked whether they felt appropriate endovascular tools for MeVO stroke exist and are available to them in their clinical practice. We then examined barriers to adopting MeVO EVT and analyzed them by geographic regions. RESULTS: A total of 263 neurointerventionists participated, of which 178 (67.7%) and 83 (31.6%) provided responses on desired qualities of MeVO EVT tools and on barriers to their adoption in local practice, respectively. The majority 121/178 (68%) felt there was substantial room for improvement regarding existing tools. A large proportion 131/178 (73.6%) felt they had appropriate access to existing tools. The most commonly mentioned barrier for adopting MeVO EVT in North America was "awaiting better tools" (9/28 responses, 32.1%), while "awaiting better evidence" (8/26 responses, 30.8%), and the need for improved "funding" (7/26 responses, 26.9%) were important barriers in Europe. CONCLUSION: The majority of surveyed neurointerventionalists felt that dedicated MeVO EVT tools can be substantially improved upon. Different regions face various challenges in adoption of MeVO EVT, but overall, physicians are mostly awaiting better MeVO EVT tools.

Prediction of 90 day home time among patients with low baseline ASPECTS undergoing endovascular thrombectomy: results from Alberta's Provincial Stroke Registry (QuICR).

BACKGROUND: The benefit of endovascular thrombectomy (EVT) in stroke patients with a low baseline Alberta Stroke Program Early CT Score (ASPECTS, ≤5) is uncertain. We aim to use random forest regression modeling to predict 90 day home time in patients with low ASPECTS. METHODS: We used the Quality Improvement and Clinical Research (QuICR) provincial stroke registry and administrative data from southern Alberta to identify patients who underwent EVT in our center from July 2015 to November 2020. Baseline ASPECTS on non-contrast CT and CT angiography data were scored by a two physician consensus. The primary outcome was the predicted 90 day home time (the number of nights a patient is back at their premorbid living situation without an increase in level of care within 90 days of the stroke) using random forests regression. Estimates were generated using 200 bootstrapped datasets. Covariate contribution to home time was determined using partial dependence plots. RESULTS: Of 657 EVT patients, 85 (12.9%) had baseline ASPECTS ≤5 (mean age 70.9 years, 44.7% women, 93.9% good-moderate collaterals, 60% M1-middle cerebral artery occlusion). Using partial dependence estimates, mean predicted home times were similar in the low ASPECTS (44.3 days) versus higher ASPECTS (43.1) groups. Factors predicting lower 90 day home time in this population were diabetes mellitus (-8.8 days), hypertension (-5.7 days), and atrial fibrillation (-3.6 days). There was no meaningful difference in predicted 90 day home time by sex, baseline National Institutes of Health Stroke Severity Scale score, occlusion site, tandem lesion, collateral grade or thrombolysis. CONCLUSIONS: Patients with low ASPECTS who are selected for EVT using demographic and clinical profiles similar to higher ASPECTS patients achieved comparable outcomes.

Validation of a machine learning software tool for automated large vessel occlusion detection in patients with suspected acute stroke.

PURPOSE: CT angiography (CTA) is the imaging standard for large vessel occlusion (LVO) detection in patients with acute ischemic stroke. StrokeSENS LVO is an automated tool that utilizes a machine learning algorithm to identify anterior large vessel occlusions (LVO) on CTA. The aim of this study was to test the algorithm's performance in LVO detection in an independent dataset. METHODS: A total of 400 studies (217 LVO, 183 other/no occlusion) read by expert consensus were used for retrospective analysis. The LVO was defined as intracranial internal carotid artery (ICA) occlusion and M1 middle cerebral artery (MCA) occlusion. Software performance in detecting anterior LVO was evaluated using receiver operator characteristics (ROC) analysis, reporting area under the curve (AUC), sensitivity, and specificity. Subgroup analyses were performed to evaluate if performance in detecting LVO differed by subgroups, namely M1 MCA and ICA occlusion sites, and in data stratified by patient age, sex, and CTA acquisition characteristics (slice thickness, kilovoltage tube peak, and scanner manufacturer). RESULTS: AUC, sensitivity, and specificity overall were as follows: 0.939, 0.894, and 0.874, respectively, in the full cohort; 0.927, 0.857, and 0.874, respectively, in the ICA occlusion cohort; 0.945, 0.914, and 0.874, respectively, in the M1 MCA occlusion cohort. Performance did not differ significantly by patient age, sex, or CTA acquisition characteristics. CONCLUSION: The StrokeSENS LVO machine learning algorithm detects anterior LVO with high accuracy from a range of scans in a large dataset.

Association of Stent-Retriever Characteristics in Establishing Successful Reperfusion During Mechanical Thrombectomy : Results from the ESCAPE-NA1 Trial.

BACKGROUND: Successful reperfusion determines the treatment effect of endovascular thrombectomy. We evaluated stent-retriever characteristics and their relation to reperfusion in the ESCAPE-NA1 trial. METHODS: Independent re-scoring of reperfusion grade for each attempt was conducted. The following characteristics were evaluated: stent-retriever length and diameter, thrombus position within stent-retriever, bypass effect, deployment in the superior or inferior MCA trunk, use of balloon guide catheter and distal access catheter. Primary outcome was successful reperfusion defined as expanded thrombolysis in cerebral infarction (eTICI) 2b-3 per attempt. The secondary outcome was successful reperfusion eTICI 2b-3 after the first attempt. Separate regression models for each stent-retriever characteristic and an exploratory multivariable modeling to test the impact of all characteristics on successful reperfusion were built. RESULTS: Of 1105 patients in the trial, 809 with the stent-retriever use (1241 attempts) were included in the primary analysis. The stent-retriever was used as the first-line approach in 751 attempts. A successful attempt was associated with thrombus position within the proximal or middle third of the stent (OR 2.06; 95% CI: 1.24-3.40 and OR 1.92; 95% CI: 1.16-3.15 compared to the distal third respectively) and with bypass effect (OR 1.7; 95% CI: 1.07-2.72). Thrombus position within the proximal or middle third (OR 2.80; 95% CI: 1.47-5.35 and OR 2.05; 95% CI: 1.09-3.84, respectively) was associated with first-pass eTICI 2b-3 reperfusion. In the exploratory analysis accounting for all characteristics, bypass effect was the only independent predictor of eTICI 2b-3 reperfusion (OR 1.95; 95% CI: 1.10-3.46). CONCLUSION: The presence of bypass effect and thrombus positioning within the proximal and middle third of the stent-retriever were strongly associated with successful reperfusion.

Willingness to randomize primary medium vessel occlusions for endovascular treatment.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke due to medium vessel occlusion (MeVO) make up a substantial part of the acute stroke population, though guidelines currently do not recommend endovascular treatment (EVT) for them. A growing body of evidence suggests that EVT is effective in MeVOs, including observational data but no randomized studies. We aimed to explore willingness of physicians worldwide to randomize MeVO stroke patients into a hypothetical trial comparing EVT in addition to best medical management versus best medical management only. METHODS: In an international cross-sectional survey among stroke physicians, participants were presented with 4 cases of primary MeVOs (6 scenarios each). Each subsequent scenario changed one key patient characteristic compared to the previous one, and asked survey participants whether they would be willing to randomize the described patient. Overall, physician- and scenario-specific decision rates were calculated. Multivariable logistic regression with clustering by respondent was performed to assess factors influencing the decision to randomize. RESULTS: Overall, 366 participants (56 women) from 44 countries provided 8784 answers to 24 MeVO case scenarios. The majority of responses (78.3%) were in favor of randomizing. Most physicians were willing to accept patients transferred for EVT from a primary center (82%) and the majority of these (76.5%) were willing to randomize these patients after transfer. Patient age > 65 years, A3 occlusion, small core volume, and patient intravenous alteplase eligibility significantly influenced the physician's decision to randomize (adjOR 1.24, 95%CI 1.13-1.36; adjOR 1.17, 95%CI 1.01-1.34; adjOR 0.98, 95%CI 0.97-0.99 and adjOR 1.38, 95%CI 1.21-1.57, respectively). CONCLUSIONS: Most physicians in this survey were willing to randomize acute MeVO stroke patients irrespective of patient characteristics into a trial comparing EVT in addition to best medical management versus best medical management only, suggesting there is clinical equipoise.

Worldwide anaesthesia use during endovascular treatment for medium vessel occlusion stroke.

INTRODUCTION: The optimal anaesthesia approach for endovascular treatment (EVT) in acute ischaemic stroke is currently unknown. In stroke due to medium vessel occlusions (MeVO), the occluded vessels are particularly small and more difficult to access, especially in restless or uncooperative patients. In these patients, general anaesthesia (GA) may be preferred by physicians to prevent complications due to patient movement. We investigated physicians' approaches to anaesthesia during EVT for MeVO stroke. METHODS: In a worldwide, case-based, online survey, physicians' preferred anaesthesia approach during EVT for MeVO stroke was categorized as "initial GA", "initial GA if necessary" (depending on patient cooperation), "no initial GA, but conversion if necessary" (start with local anaesthesia or conscious sedation), and "no GA". Preferred anaesthesia approaches were reported overall and stratified by physician and patient characteristics. RESULTS: A total of 366 survey participants provided 1464 responses to 4 primary MeVO EVT case-scenarios. One-third of responses (489/1464 [33%]) favoured no initial GA, but conversion if necessary. Both initial GA and initial GA if necessary were preferred in 368/1464 (25%) of responses respectively. No GA was favoured in 244/1464 (17%). Occlusion location, respondent specialization (interventional neuroradiology), higher age, and female respondent sex were significantly associated with GA preference. GA was more often used in Europe than in other parts of the world (p < 0.001). CONCLUSIONS: Anaesthesia approaches in MeVO EVT vary across world regions and patient and physician factors. Most physicians in this survey preferred to start with local anaesthesia or conscious sedation and convert to GA if necessary.