Trial of Thrombectomy for Stroke with a Large Infarct of Unrestricted Size.

BACKGROUND: The use of thrombectomy in patients with acute stroke and a large infarct of unrestricted size has not been well studied. METHODS: We assigned, in a 1:1 ratio, patients with proximal cerebral vessel occlusion in the anterior circulation and a large infarct (as defined by an Alberta Stroke Program Early Computed Tomographic Score of ≤5; values range from 0 to 10) detected on magnetic resonance imaging or computed tomography within 6.5 hours after symptom onset to undergo endovascular thrombectomy and receive medical care (thrombectomy group) or to receive medical care alone (control group). The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The primary safety outcome was death from any cause at 90 days, and an ancillary safety outcome was symptomatic intracerebral hemorrhage. RESULTS: A total of 333 patients were assigned to either the thrombectomy group (166 patients) or the control group (167 patients); 9 were excluded from the analysis because of consent withdrawal or legal reasons. The trial was stopped early because results of similar trials favored thrombectomy. Approximately 35% of the patients received thrombolysis therapy. The median modified Rankin scale score at 90 days was 4 in the thrombectomy group and 6 in the control group (generalized odds ratio, 1.63; 95% confidence interval [CI], 1.29 to 2.06; P<0.001). Death from any cause at 90 days occurred in 36.1% of the patients in the thrombectomy group and in 55.5% of those in the control group (adjusted relative risk, 0.65; 95% CI, 0.50 to 0.84), and the percentage of patients with symptomatic intracerebral hemorrhage was 9.6% and 5.7%, respectively (adjusted relative risk, 1.73; 95% CI, 0.78 to 4.68). Eleven procedure-related complications occurred in the thrombectomy group. CONCLUSIONS: In patients with acute stroke and a large infarct of unrestricted size, thrombectomy plus medical care resulted in better functional outcomes and lower mortality than medical care alone but led to a higher incidence of symptomatic intracerebral hemorrhage. (Funded by Montpellier University Hospital; LASTE ClinicalTrials.gov number, NCT03811769.).

Trial of Thrombectomy 6 to 24 Hours after Stroke Due to Basilar-Artery Occlusion.

BACKGROUND: The effects and risks of endovascular thrombectomy 6 to 24 hours after stroke onset due to basilar-artery occlusion have not been extensively studied. METHODS: In a trial conducted over a 5-year period in China, we randomly assigned, in a 1:1 ratio, patients with basilar-artery stroke who presented between 6 to 24 hours after symptom onset to receive either medical therapy plus thrombectomy or medical therapy only (control). The original primary outcome, a score of 0 to 4 on the modified Rankin scale (range, 0 to 6, with a score of 0 indicating no disability, 4 moderately severe disability, and 6 death) at 90 days, was changed to a good functional status (a modified Rankin scale score of 0 to 3, with a score of 3 indicating moderate disability). Primary safety outcomes were symptomatic intracranial hemorrhage at 24 hours and 90-day mortality. RESULTS: A total of 217 patients (110 in the thrombectomy group and 107 in the control group) were included in the analysis; randomization occurred at a median of 663 minutes after symptom onset. Enrollment was halted at a prespecified interim analysis because of the superiority of thrombectomy. Thrombolysis was used in 14% of the patients in the thrombectomy group and in 21% of those in the control group. A modified Rankin scale score of 0 to 3 (primary outcome) occurred in 51 patients (46%) in the thrombectomy group and in 26 (24%) in the control group (adjusted rate ratio, 1.81; 95% confidence interval [CI], 1.26 to 2.60; P<0.001). The results for the original primary outcome of a modified Rankin scale score of 0 to 4 were 55% and 43%, respectively (adjusted rate ratio, 1.21; 95% CI, 0.95 to 1.54). Symptomatic intracranial hemorrhage occurred in 6 of 102 patients (6%) in the thrombectomy group and in 1 of 88 (1%) in the control group (risk ratio, 5.18; 95% CI, 0.64 to 42.18). Mortality at 90 days was 31% in the thrombectomy group and 42% in the control group (adjusted risk ratio, 0.75; 95% CI, 0.54 to 1.04). Procedural complications occurred in 11% of the patients who underwent thrombectomy. CONCLUSIONS: Among patients with stroke due to basilar-artery occlusion who presented 6 to 24 hours after symptom onset, thrombectomy led to a higher percentage with good functional status at 90 days than medical therapy but was associated with procedural complications and more cerebral hemorrhages. (Funded by the Chinese National Ministry of Science and Technology; BAOCHE ClinicalTrials.gov number, NCT02737189.).

Mode of Onset Modifies the Effect of Time to Endovascular Reperfusion on Clinical Outcomes after Acute Ischemic Stroke: An Analysis of the DAWN Trial.

OBJECTIVE: We aimed to assess the impact of time to endovascular thrombectomy (EVT) on clinical outcomes in the DAWN trial, while also exploring the potential effect modification of mode of stroke onset on this relationship. METHODS: The association between every 1-h treatment delay with 90-day functional independence (modified Rankin Scale [mRS] score 0-2), symptomatic intracranial hemorrhage, and 90-day mortality was explored in the overall population and in three modes of onset subgroups (wake-up vs. witnessed vs. unwitnessed). RESULTS: Out of the 205 patients, 98 (47.8%) and 107 (52.2%) presented in the 6 to 12 hours and 12 to 24 hours time window, respectively. Considering all three modes of onset together, there was no statistically significant association between time last seen well to randomization with either functional independence or mortality at 90 days in either the endovascular thrombectomy (mRS 0-2 1-hour delay OR 1.07; 95% CI 0.93-1.24; mRS 6 OR 0.84; 95% CI 0.65-1.03) or medical management (mRS 0-2 1-hour delay OR 0.98; 95% CI 0.80-1.14; mRS 6 1-hour delay OR 0.94; 95% CI 0.79-1.09) groups. Moreover, there was no significant interaction between treatment effect and time (p = 0.439 and p = 0.421 for mRS 0-2 and 6, respectively). However, within the thrombectomy group, the models that tested the association between time last seen well to successful reperfusion (modified Treatment in Cerebral Infarction ≥2b) and 90-day functional independence showed a significant interaction with mode of presentation (p = 0.013). This appeared to be driven by a nominally positive slope for both witnessed and unwitnessed strokes versus a significantly (p = 0.018) negative slope in wake-up patients. There was no association between treatment times and symptomatic intracranial hemorrhage. INTERPRETATION: Mode of onset modifies the effect of time to reperfusion on thrombectomy outcomes, and should be considered when exploring different treatment paradigms in the extended window. ANN NEUROL 2024.

What Is a Meaningful Difference When Using Infarct Volume as the Primary Outcome?: Results From the HERMES Database.

BACKGROUND: Ischemic stroke lesion volume at follow-up is an important surrogate outcome for acute stroke trials. We aimed to assess which differences in 48-hour lesion volume translate into meaningful clinical differences. METHODS: We used pooled data from 7 trials investigating the efficacy of endovascular treatment for anterior circulation large vessel occlusion in acute ischemic stroke. We assessed 48-hour lesion volume follow-up computed tomography or magnetic resonance imaging. The primary outcome was a good functional outcome, defined as modified Rankin Scale (mRS) scores of 0 to 2. We performed multivariable logistic regression to predict the probability of achieving mRS scores of 0 to 2 and determined the differences in 48-hour lesion volume that correspond to a change of 1%, 5%, and 10% in the adjusted probability of achieving mRS scores of 0 to 2. RESULTS: In total, 1665/1766 (94.2%) patients (median age, 68 [interquartile range, 57-76] years, 781 [46.9%] female) had information on follow-up ischemic lesion volume. Computed tomography was used for follow-up imaging in 83% of patients. The median 48-hour lesion volume was 41 (interquartile range, 14-120) mL. We observed a linear relationship between 48-hour lesion volume and mRS scores of 0 to 2 for adjusted probabilities between 65% and 20%/volumes <80 mL, although the curve sloped off for lower mRS scores of 0-2 probabilities/higher volumes. The median differences in 48-hour lesion volume associated with a 1%, 5%, and 10% increase in the probability of mRS scores of 0 to 2 for volumes <80 mL were 2 (interquartile range, 2-3), 10 (9-11), and 20 (18-23) mL, respectively. We found comparable associations when assessing computed tomography and magnetic resonance imaging separately. CONCLUSIONS: A difference of 2, 10, and 20 mL in 48-hour lesion volume, respectively, is associated with a 1%, 5%, and 10% absolute increase in the probability of achieving good functional outcome. These results can inform the design of future stroke trials that use 48-hour lesion volume as the primary outcome.

Projections of Endovascular Therapy-Eligible Patients With Stroke for the US Population.

BACKGROUND: As stroke endovascular thrombectomy (EVT) treatment indications expand, understanding population-based EVT eligibility becomes critical for resource planning. We aimed to project current and future population-based EVT eligibility in the United States. METHODS: We conducted a post hoc analysis of the physician-adjudicated GCNKSS (Greater Cincinnati Northern Kentucky Stroke Study; 2015 epoch), a population-based, cross sectional, observational study of stroke incidence, treatment, and outcomes across a 5-county region. All hospitalized patients ≥18 years of age with acute ischemic stroke were ascertained using the International Classification of Diseases, Ninth Revision codes 430-436 and Tenth Revision codes I60-I67 and G45-G46 and extrapolated to the US adult census 2020. We determined the rate of EVT eligibility within the GCNKSS population using time from last known well to presentation (0-5 versus 5-23 hours), presenting National Institutes of Health Stroke Scale, and prestroke modified Rankin Scale. Both conservative and liberal estimates of prevalence of large vessel occlusion and large core were then applied based on literature review (unavailable within the 2015 GCNKSS). This eligibility was then extrapolated to the 2020 US population. RESULTS: Of the 1 057 183 adults within GCNKSS in 2015, 2741 had an ischemic stroke and 2176 had data available for analysis. We calculated that 8659 to 17 219 patients (conservative to liberal) meet the current guideline-recommended EVT criteria (nonlarge core, no prestroke disability, and National Institutes of Health Stroke Scale score ≥6) in the United States. Estimates (conservative to liberal) for expanded EVT eligibility subpopulations include (1) 5316 to 10 635 by large core; (2) 10 635 to 21 270 by mild presenting deficits with low National Institutes of Health Stroke Scale score; (3) 13 572 to 27 089 by higher prestroke disability; and (4) 7039 to 14 180 by >1 criteria. These expanded eligibility subpopulations amount to 36 562 to 73 174 patients. CONCLUSIONS: An estimated 8659 to 17 219 adult patients in the United States met strict EVT eligibility criteria in 2020. A 4-fold increase in population-based EVT eligibility can be anticipated with incremental adoption of recent or future positive trials. US stroke systems need to be rapidly optimized to handle all EVT-eligible patients with stroke.

Cervical Dissection in Patients With Tandem Lesions Is Associated With Distal Embolism and Lower Recanalization Success.

BACKGROUND: Tandem lesions consist of cervical internal carotid artery (ICA) stenosis or occlusion, most commonly of atherosclerosis or dissection etiology, plus a large vessel occlusion. In this study, we compare outcomes in patients with atherosclerosis versus dissection of the cervical ICA. METHODS: This multicenter retrospective cohort study includes data from tandem lesion patients who underwent endovascular treatment from 2015 to 2020. Atherosclerosis was defined as ICA stenosis/occlusion associated with a calcified lesion and dissection by the presence of a tapered or flame-shaped lesion and intramural hematoma. Primary outcome: 90-day functional independence (modified Rankin Scale score, 0-2); secondary outcomes: 90-day favorable shift in the modified Rankin Scale score, modified Thrombolysis in Cerebral Infarction score 2b-3, modified Thrombolysis in Cerebral Infarction score 2c-3, symptomatic intracranial hemorrhage, parenchymal hematoma type 2, petechial hemorrhage, distal embolization, early neurological improvement, and mortality. Analysis was performed with matching by inverse probability of treatment weighting. RESULTS: We included 526 patients (68 [59-76] years; 31% females); 11.2% presented dissection and 88.8%, atherosclerosis. Patients with dissection were younger, had lower rates of hypertension, hyperlipidemia, diabetes, and smoking history. They also exhibited higher rates of ICA occlusion, multiple stents (>1), and lower rates of carotid self-expanding stents. After matching and adjusting for covariates, there were no differences in 90-day functional independence. The rate of successful recanalization was significantly lower in the dissection group (adjusted odds ratio, 0.38 [95% CI, 0.16-0.91]; P=0.031), which also had significantly higher rates of distal emboli (adjusted odds ratio, 2.53 [95% CI, 1.15-5.55]; P=0.021). There were no differences in other outcomes. Acute ICA stenting seemed to increase the effect of atherosclerosis in successful recanalization. CONCLUSIONS: This study reveals that among patients with acute stroke with tandem lesions, cervical ICA dissection is associated with higher rates of distal embolism and lower rates of successful recanalization than atherosclerotic lesions. Using techniques to minimize the risk of distal embolism may mitigate this contrast. Further prospective randomized trials are warranted to fully understand these associations.

Real-World Outcomes of Endovascular Thrombectomy for Basilar Artery Occlusion: Results of the BArONIS Study.

OBJECTIVE: To evaluate clinical outcomes of endovascular thrombectomy (EVT) for acute basilar artery occlusion (BAO) using population-level data from the United States. METHODS: Weighted discharge data from the National Inpatient Sample were queried to identify adult patients with acute BAO during the period of 2015 to 2019 treated with EVT or medical management only. Complex samples statistical methods and propensity-score adjustment using inverse probability of treatment weighting (IPTW) were performed to assess clinical endpoints. RESULTS: Among 3,950 BAO patients identified, 1,425 (36.1%) were treated with EVT [mean age 66.7 years, median National Institute of Health Stroke Scale (NIHSS) score 22]. On unadjusted analysis, 155 (10.9%) EVT patients achieved favorable functional outcomes (discharge disposition to home without services), while 515 (36.1%) experienced in-hospital mortality, and 20 (1.4%) developed symptomatic intracranial hemorrhage (sICH). Following propensity-score adjustment by IPTW accounting for age, stroke severity, and comorbidity burden, EVT was independently associated with favorable functional outcome [adjusted odds ratio (aOR) 1.25, 95% confidence interval (CI) 1.07, 1.46; p = 0.004], but not with in-hospital mortality or sICH. In an IPTW-adjusted sub-group analysis of patients with NIHSS scores >20, EVT was associated with both favorable functional outcome (discharge disposition to home or to acute rehabilitation) (aOR 1.55, 95% CI 1.24, 1.94; p < 0.001) and decreased mortality (aOR 0.78, 95% CI 0.69, 0.89; p < 0.001), but not with sICH. INTERPRETATION: This retrospective population-based analysis using a large national registry provides real-world evidence of a potential benefit of EVT in acute BAO patients. ANN NEUROL 2023;94:55-60.

Direct Transfer to the Neuroangiography Suite for Patients With Stroke.

The therapeutic focus in acute ischemic stroke over the last 2.5 decades has been to balance the benefits of rapid reperfusion therapy with the risks of treatment-related complications. Both intravenous thrombolytics and endovascular thrombectomy are proven to substantially improve outcomes in a time-dependent manner. Each minute saved in achieving successful reperfusion grants an additional week of healthy life and may salvage up to 27 million neurons. The current approach to patient triage is inherited from the preendovascular thrombectomy era of stroke care. Current workflow concentrates on stabilization, diagnosis, and decision-making in the emergency department, followed by thrombolysis if eligible and subsequent transfer to the angiography suite as needed for further treatment. Multiple efforts have been directed toward minimizing the time from first medical contact to reperfusion therapy including prehospital triage and intrahospital workflow. Novel approaches for stroke patient triage such as the direct to angio approach, (also referred to as One Stop Management) are currently in development. The concept was initially introduced as several single-center experiences. In this narrative review article, we will consider various definitions of direct to angio and its variants, discuss its rationale, review its safety and efficacy, assess its feasibility, and delineate its limitations. Further, we will address methods to overcome these limitations and the potential impact of emerging data and new technologies on the direct-to-angio approach.

Cost-Effectiveness of Endovascular Treatment in Large Vessel Occlusion Stroke With Mild Prestroke Disability: Results From the HERMES Collaboration.

BACKGROUND: The clinical and economic benefit of endovascular treatment (EVT) in addition to best medical management in patients with stroke with mild preexisting symptoms/disability is not well studied. We aimed to investigate cost-effectiveness of EVT in patients with large vessel occlusion and mild prestroke symptoms/disability, defined as a modified Rankin Scale score of 1 or 2. METHODS: Data are from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials), which pooled patient-level data from 7 large, randomized EVT trials. We used a decision model consisting of a short-run model to analyze costs and functional outcomes within 90 days after the index stroke and a long-run Markov state transition model (cycle length of 12 months) to estimate expected lifetime costs and outcomes from a health care and a societal perspective. Incremental cost-effectiveness ratio and net monetary benefits were calculated, and a probabilistic sensitivity analysis was performed. RESULTS: EVT in addition to best medical management resulted in lifetime cost savings of $2821 (health care perspective) or $5378 (societal perspective) and an increment of 1.27 quality-adjusted life years compared with best medical management alone, indicating dominance of additional EVT as a treatment strategy. The net monetary benefits were higher for EVT in addition to best medical management compared with best medical management alone both at the higher (100 000$/quality-adjusted life years) and lower (50 000$/quality-adjusted life years) willingness to pay thresholds. Probabilistic sensitivity analysis showed decreased costs and an increase in quality-adjusted life years for additional EVT compared with best medical management only. CONCLUSIONS: From a health-economic standpoint, EVT in addition to best medical management should be the preferred strategy in patients with acute ischemic stroke with large vessel occlusion and mild prestroke symptoms/disability.

Association of Time of Day With Outcomes Among Patients Triaged for a Suspected Severe Stroke in Nonurban Catalonia.

BACKGROUND: We aim to assess whether time of day modified the treatment effect in the RACECAT trial (Direct Transfer to an Endovascular Center Compared to Transfer to the Closest Stroke Center in Acute Stroke Patients With Suspected Large Vessel Occlusion Trial), a cluster-randomized trial that did not demonstrate the benefit of direct transportation to a thrombectomy-capable center versus nearest local stroke center for patients with a suspected large vessel stroke triaged in nonurban Catalonia between March 2017 and June 2020. METHODS: We performed a post hoc analysis of RACECAT to evaluate if the association between initial transport routing and functional outcome differed according to trial enrollment time: daytime (8:00 am-8:59 pm) and nighttime (9:00 pm-7:59 am). Primary outcome was disability at 90 days, as assessed by the shift analysis on the modified Rankin Scale score, in patients with ischemic stroke. Subgroup analyses according to stroke subtype were evaluated. RESULTS: We included 949 patients with an ischemic stroke, of whom 258 patients(27%) were enrolled during nighttime. Among patients enrolled during nighttime, direct transport to a thrombectomy-capable center was associated with lower degrees of disability at 90 days (adjusted common odds ratio [acOR], 1.620 [95% CI, 1.020-2.551]); no significant difference between trial groups was present during daytime (acOR, 0.890 [95% CI, 0.680-1.163]; P interaction=0.014). Influence of nighttime on the treatment effect was only evident in patients with large vessel occlusion(daytime, acOR 0.766 [95% CI, 0.548-1.072]; nighttime, acOR, 1.785 [95% CI, 1.024-3.112] ; P interaction<0.01); no heterogeneity was observed for other stroke subtypes (P interaction>0.1 for all comparisons). We observed longer delays in alteplase administration, interhospital transfers, and mechanical thrombectomy initiation during nighttime in patients allocated to local stroke centers. CONCLUSIONS: Among patients evaluated during nighttime for a suspected acute severe stroke in non-urban areas of Catalonia, direct transport to a thrombectomy-capable center was associated with lower degrees of disability at 90 days. This association was only evident in patients with confirmed large vessel occlusion on vascular imaging. Time delays in alteplase administration and interhospital transfers might mediate the observed differences in clinical outcome. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02795962.

Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis.

BACKGROUND: Trials examining the benefit of thrombectomy in anterior circulation proximal large vessel occlusion stroke have enrolled patients considered to have salvageable brain tissue, who were randomly assigned beyond 6 h and (depending on study protocol) up to 24 h from time last seen well. We aimed to estimate the benefit of thrombectomy overall and in prespecified subgroups through individual patient data meta-analysis. METHODS: We did a systematic review and individual patient data meta-analysis between Jan 1, 2010, and March 1, 2021, of randomised controlled trials of endovascular stroke therapy. In the Analysis Of Pooled Data From Randomized Studies Of Thrombectomy More Than 6 Hours After Last Known Well (AURORA) collaboration, the primary outcome was disability on the modified Rankin Scale (mRS) at 90 days, analysed by ordinal logistic regression. Key safety outcomes were symptomatic intracerebral haemorrhage and mortality within 90 days. FINDINGS: Patient level data from 505 individuals (n=266 intervention, n=239 control; mean age 68·6 years [SD 13·7], 259 [51·3%] women) were included from six trials that met inclusion criteria of 17 screened published randomised trials. Primary outcome analysis showed a benefit of thrombectomy with an unadjusted common odds ratio (OR) of 2·42 (95% CI 1·76-3·33; p<0·0001) and an adjusted common OR (for age, gender, baseline stroke severity, extent of infarction on baseline head CT, and time from onset to random assignment) of 2·54 (1·83-3·54; p<0·0001). Thrombectomy was associated with higher rates of independence in activities of daily living (mRS 0-2) than best medical therapy alone (122 [45·9%] of 266 vs 46 [19·3%] of 238; p<0·0001). No significant difference between intervention and control groups was found when analysing either 90-day mortality (44 [16·5%] of 266 vs 46 [19·3%] of 238) or symptomatic intracerebral haemorrhage (14 [5·3%] of 266 vs eight [3·3%] of 239). No heterogeneity of treatment effect was noted across subgroups defined by age, gender, baseline stroke severity, vessel occlusion site, baseline Alberta Stroke Program Early CT Score, and mode of presentation; treatment effect was stronger in patients randomly assigned within 12-24 h (common OR 5·86 [95% CI 3·14-10·94]) than those randomly assigned within 6-12 h (1·76 [1·18-2·62]; pinteraction=0·0087). INTERPRETATION: These findings strengthen the evidence for benefit of endovascular thrombectomy in patients with evidence of reversible cerebral ischaemia across the 6-24 h time window and are relevant to clinical practice. Our findings suggest that in these patients, thrombectomy should not be withheld on the basis of mode of presentation or of the point in time of presentation within the 6-24 h time window. FUNDING: Stryker Neurovascular.

Workflow Times and Outcomes in Patients Triaged for a Suspected Severe Stroke.

INTRODUCTION: Current recommendations for regional stroke destination suggest that patients with severe acute stroke in non-urban areas should be triaged based on the estimated transport time to a referral thrombectomy-capable center. METHODS: We performed a post hoc analysis to evaluate the association of pre-hospital workflow times with neurological outcomes in patients included in the RACECAT trial. Workflow times evaluated were known or could be estimated before transport allocation. Primary outcome was the shift analysis on the modified Rankin score at 90 days. RESULTS: Among the 1,369 patients included, the median time from onset to emergency medical service (EMS) evaluation, the estimated transport time to a thrombectomy-capable center and local stroke center, and the estimated transfer time between centers were 65 minutes (interquartile ratio [IQR] = 43-138), 61 minutes (IQR = 36-80), 17 minutes (IQR = 9-27), and 62 minutes (IQR = 36-73), respectively. Longer time intervals from stroke onset to EMS evaluation were associated with higher odds of disability at 90 days in the local stroke center group (adjusted common odds ratio (acOR) for each 30-minute increment = 1.03, 95% confidence interval [CI] = 1.01-1.06), with no association in the thrombectomy-capable center group (acOR for each 30-minute increment = 1.01, 95% CI = 0.98-1.01, pinteraction  = 0.021). No significant interaction was found for other pre-hospital workflow times. In patients evaluated by EMS later than 120 minutes after stroke onset, direct transport to a thrombectomy-capable center was associated with better disability outcomes (acOR = 1.49, 95% CI = 1.03-2.17). CONCLUSION: We found a significant heterogeneity in the association between initial transport destination and neurological outcomes according to the elapse of time between the stroke onset and the EMS evaluation (ClinicalTrials.gov: NCT02795962). ANN NEUROL 2022;92:931-942.

Endovascular Treatment for Acute Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Disease.

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of acute ischemic stroke worldwide. Patients with acute large vessel occlusion due to underlying ICAD (ICAD-LVO) often do not achieve successful recanalization when undergoing mechanical thrombectomy (MT) alone, requiring rescue treatment, including intra-arterial thrombolysis, balloon angioplasty, and stenting. Therefore, early detection of ICAD-LVO before the procedure is important to enable physicians to select the optimal treatment strategy for ICAD-LVO to improve clinical outcomes. Early diagnosis of ICAD-LVO is challenging in the absence of consensus diagnostic criteria on noninvasive imaging and early digital subtraction angiography. In this review, we summarize the clinical and diagnostic criteria, prediction of ICAD-LVO prior to the procedure, and EVT strategy of ICAD-LVO and provide recommendations according to the current literature.

First Pass Effect With Neurothrombectomy for Acute Ischemic Stroke: Analysis of the Systematic Evaluation of Patients Treated With Stroke Devices for Acute Ischemic Stroke Registry.

BACKGROUND AND PURPOSE: Achieving complete revascularization after a single pass of a mechanical thrombectomy device (first pass effect [FPE]) is associated with good clinical outcomes in patients with acute ischemic stroke due to large vessel occlusion. We assessed patient characteristics, outcomes, and predictors of FPE among a large real-world cohort of patients (Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke registry). METHODS: Demographics, clinical outcomes, and procedural characteristics were analyzed among patients in whom FPE (modified Thrombolysis in Cerebral Infarction 2c/3 after first pass) was achieved versus those requiring multiple passes (MP). Modified FPE and modified MP included patients achieving modified Thrombolysis in Cerebral Infarction 2B-3. Primary outcomes included 90-day modified Rankin Scale (mRS) score and mortality. RESULTS: Among 984 Systematic Evaluation of Patients Treated with Stroke Devices for Acute Ischemic Stroke patients, 930 had complete 90-day follow-up. FPE was achieved in 40.5% (377/930) of patients and MP in 20.0% (186/930). Baseline characteristics were similar across all groups. The FPE group had fewer internal carotid artery occlusions compared with MP (P=0.029). The FPE group had faster puncture to recanalization time (P≤0.001), higher rates of 90-day mRS score of 0 to 1 (52.6% versus 38.6%, P=0.003), mRS score of 0 to 2 (65.4% versus 52.0%, P=0.003), and lower 90-day mortality compared with the MP group (12.0% versus 18.7%, P=0.038). Similarly, compared with modified MP patients, the modified FPE group had fewer internal carotid artery occlusions (P=0.004), faster puncture to recanalization time (P≤0.001), and higher rates of 90-day mRS score of 0 to 1 (P=0.002) and mRS score of 0 to 2 (P=0.003). CONCLUSIONS: Our findings demonstrate that FPE and modified FPE are associated with superior clinical outcomes.

Functional Outcomes of Patients ≥85 Years With Acute Ischemic Stroke Following EVT: A HERMES Substudy.

BACKGROUND: Observational studies have shown endovascular treatment (EVT) for acute ischemic stroke to be effective in the elderly, despite resulting in poorer outcomes and higher rates of mortality compared with younger patients. Randomized data on the effect of advanced age on outcomes following EVT are, however, lacking. Our aim was to assess the EVT effect for ischemic stroke in patients aged ≥85 years and the influence of age on outcome in a large, randomized trial dataset. METHODS: Data were from the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) collaboration, a meta-analysis of 7 randomized trials published between January 1, 2010, and May 31, 2017, that tested the efficacy of EVT. A possible multiplicative interaction effect of age on the relationship between treatment and outcome was investigated. Ordinal logistic regression tested the association between EVT and 90-day functional outcome (modified Rankin Scale, primary outcome) in patients ≥85 years. Multivariable binary logistic regression was performed to compare primary and secondary outcomes (modified Rankin Scale score of 0-2/5-6) of patients ≥85 years versus those <85 years. RESULTS: We included 1764 patients in the analysis, of whom 77 (4.4%) were ≥85 years old. A significant interaction of age and treatment on poor outcome (modified Rankin Scale score of 5-6, P=0.020) and mortality (P=0.031) was observed, with older adults having worse functional outcomes at 90 days compared with younger patients (adjusted common odds ratio, 0.20 [95% CI, 0.13-0.33]). However, a benefit of EVT was observed in the ≥85-year-old patient subgroup (common odds ratio, 4.20 [95% CI, 1.56-11.32]). Age ≥85 years was not significantly associated with differing rates of symptomatic intracerebral hemorrhage or reperfusion (adjusted odds ratio, 1.92 [95% CI, 0.71-5.15] and adjusted odds ratio, 0.91 [95% CI, 0.40-2.06], respectively). CONCLUSIONS: Patients ≥85 years old with independent premorbid function more often achieve good functional outcomes and have lower rates of mortality when treated with EVT compared with conservative management, with an observed treatment effect modification of age on outcome. EVT should therefore not be withheld in this subgroup.

Thrombectomy With and Without Computed Tomography Perfusion Imaging in the Early Time Window: A Pooled Analysis of Patient-Level Data.

BACKGROUND: The optimal imaging paradigm for endovascular thrombectomy (EVT) patient selection in early time window (0-6 hours) treated acute ischemic stroke patients remains uncertain. We aimed to compare post-EVT outcomes between patients who underwent prerandomization basic (noncontrast computed tomography [CT], CT angiography only) versus additional advanced imaging (computed tomography perfusion [CTP] imaging) and to determine the association of performance of prerandomization CTP imaging with clinical outcomes. METHODS: The HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) pooled patient-level data from randomized controlled trials comparing EVT with usual care for acute ischemic stroke due to anterior circulation large vessel occlusion. Good functional outcome, defined as modified Rankin Scale score 0 to 2 at 90 days, was compared between randomized patients with and without CTP baseline imaging. Univariable and multivariable binary logistic regression analysis was performed to determine the association of baseline CTP imaging and good functional outcome. RESULTS: We analyzed 1348 patients 610 (45.3%) of whom underwent CTP prerandomization. The benefit of EVT compared with best medical management was maintained irrespective of the baseline imaging paradigm (90-day modified Rankin Scale score 0-2 in EVT versus control patients: with CTP: 46.0% (137/298) versus 28.9% (88/305), without CTP: 44.1% (162/367) versus 27.3% (100/366). Performance of CTP baseline imaging compared with baseline noncontrast CT and CT angiography only yielded similar rates of good outcome (odds ratio, 1.05 [95% CI, 0.82-1.33], adjusted odds ratio, 1.04, [95% CI, 0.80-1.35]). CONCLUSIONS: Rates of good functional outcome were similar among patients in whom CTP was or was not performed, and EVT treatment effect in the 0- to 6-hour time window was similar in patients with and without baseline CTP imaging.

Significance of Baseline Ischemic Core Volume on Stroke Outcome After Endovascular Therapy in Patients Age ≥75 Years: A Pooled Analysis of Individual Patient Data From 7 Trials.

BACKGROUND: Age and infarct volume are strong predictors of outcome in patients with ischemic stroke who underwent endovascular therapy (EVT). We aimed to investigate the impact of ischemic core volume (ICV) on stroke outcome after EVT in elderly. METHODS: Using the HERMES (Highly Effective Reperfusion Using Multiple Endovascular Devices) collaboration, a patient-level meta-analysis of 7 randomized trials in which patients were enrolled from December 2010 to April 2015) dataset, we categorized patients into those aged <75 and ≥75 years. ICV was calculated on computed tomography perfusion or magnetic resonance diffusion-weighted imaging. The association between ICV and the benefit of EVT over best medical treatment on outcome (modified Rankin Scale [mRS] at 90 days) and an ICV threshold for high likelihood (≥90%) of very poor outcome (mRS score ≥5) after EVT were investigated. RESULTS: A total of 899 patients who had baseline ICV data, 247 patients aged ≥75 years, of which 118 were randomized in the EVT arm. Patients aged ≥75 years required smaller ICV to achieve mRS score ≤3 than those aged <75 years in the EVT arm (median 10.7 mL versus 23.9 mL, P<0.001). In patients aged ≥75 years, modeling of outcome in both treatment arms revealed potential loss of effect for EVT at ICV of ≥50 mL or ≥85 mL for achieving mRS score ≤3 or ≤4, respectively. Treatment effect of EVT was significant in ICV <50 mL for mRS ≤3 (odds ratio 2.38, 95% confidence interval 1.35-4.22). ICV ≥132 mL was a threshold for high likelihood of very poor outcome after EVT. However, EVT still predicted at least 30% rate of mRS ≤3 at 150 mL ICV if near-complete or complete reperfusion was achieved. CONCLUSIONS: Baseline ICV has an impact on stroke outcome after EVT in the elderly, but elderly patients with large ICV may still benefit from EVT if near-complete or complete reperfusion is achieved. Young patients seem to benefit from EVT regardless of ICV status.

Collateral Circulation in Thrombectomy for Stroke After 6 to 24 Hours in the DAWN Trial.

BACKGROUND AND PURPOSE: Collaterals govern the pace and severity of cerebral ischemia, distinguishing fast or slow progressors and corresponding therapeutic opportunities. The fate of sustained collateral perfusion or collateral failure is poorly characterized. We evaluated the nature and impact of collaterals on outcomes in the late time window DAWN trial (Diffusion-Weighted Imaging or Computed Tomography Perfusion Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo). METHODS: The DAWN Imaging Core Lab prospectively scored collateral grade on baseline computed tomography angiography (CTA; endovascular and control arms) and digital subtraction angiography (DSA; endovascular arm only), blinded to all other data. CTA collaterals were graded with the Tan scale and DSA collaterals were scored by ASITN grade (American Society of Interventional and Therapeutic Neuroradiology collateral score). Descriptive statistics characterized CTA collateral grade in all DAWN subjects and DSA collaterals in the endovascular arm. The relationship between collateral grade and day 90 outcomes were separately analyzed for each treatment arm. RESULTS: Collateral circulation to the ischemic territory was evaluated on CTA (n=144; median 2, 0-3) and DSA (n=57; median 2, 1-4) before thrombectomy in 161 DAWN subjects (mean age 69.8±13.6 years; 55.3% women; 91 endovascular therapy, 70 control). CTA revealed a broad range of collaterals (Tan grade 3, n=64 [44%]; 2, n=45 [31%]; 1, n=31 [22%]; 0, n=4 [3%]). DSA also showed a diverse range of collateral grades (ASITN grade 4, n=4; 3, n=22; 2, n=27; 1, n=4). Across treatment arms, baseline demographics, clinical variables except atrial fibrillation (41.6% endovascular versus 25.0% controls, P=0.04), and CTA collateral grades were balanced. Differences were seen across the 3 levels of collateral flow (good, fair, poor) for baseline National Institutes of Health Stroke Scale, blood glucose <150, diabetes, previous ischemic stroke, baseline and 24-hour core infarct volume, baseline and 24-hour Alberta Stroke Program Early CT Score, dramatic infarct progression, final Thrombolysis in Cerebral Infarction 2b+, and death. Collateral flow was a significant predictor of 90-day modified Rankin Scale score of 0 to 2 in the endovascular arm, with 43.7% (31/71) of subjects with good collaterals, 30.8% (16/52) of subjects with fair collaterals, and 17.7% (6/34) of subjects with poor collaterals reaching modified Rankin Scale score of 0 to 2 at 90 days (P=0.026). CONCLUSIONS: DAWN subjects enrolled at 6 to 24 hours after onset with limited infarct cores had a wide range of collateral grades on both CTA and DSA. Even in this late time window, better collaterals lead to slower stroke progression and better functional outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02142283.

Correlation Between Computed Tomography-Based Tissue Net Water Uptake and Volumetric Measures of Cerebral Edema After Reperfusion Therapy.

BACKGROUND: Cerebral edema after large hemispheric infarction is associated with poor functional outcome and mortality. Net water uptake (NWU) quantifies the degree of hypoattenuation on unenhanced-computed tomography (CT) and is increasingly used to measure cerebral edema in stroke research. Hemorrhagic transformation and parenchymal contrast staining after thrombectomy may confound NWU measurements. We investigated the correlation of NWU measured postthrombectomy with volumetric markers of cerebral edema and association with functional outcomes. METHODS: In a pooled individual patient level analysis of patients presenting with anterior circulation large hemispheric infarction (core 80-300 mL or Alberta Stroke Program Early CT Score ≤5) in the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke trials) data set, cerebral edema was defined as the volumetric expansion of the ischemic hemisphere expressed as a ratio to the contralateral hemisphere(rHV). NWU and midline-shift were compared with rHV as the reference standard on 24-hour follow-up CT, adjusted for hemorrhagic transformation and the use of thrombectomy. Association between edema markers and day 90 functional outcomes (modified Rankin Scale) was assessed using ordinal logistic regression. RESULTS: Overall (n=144), there was no correlation between NWU and rHV (rs=0.055, P=0.51). In sub-group analyses, a weak correlation between NWU with rHV was observed after excluding patients with any degree of hemorrhagic transformation (rs=0.211, P=0.015), which further improved after excluding thrombectomy patients (rs=0.453, P=0.001). Midline-shift correlated strongly with rHV in all sub-group analyses (rs>0.753, P=0.001). Functional outcome at 90 days was negatively associated with rHV (adjusted common odds ratio, 0.46 [95% CI, 0.32-0.65]; P<0.001) and midline-shift (adjusted common odds ratio, 0.85 [95% CI, 0.78-0.92]; P<0.001) but not NWU (adjusted common odds ratio, 1.00 [95% CI, 0.97-1.03]; P=0.84), adjusted for age, baseline National Institutes of Health Stroke Scale, and thrombectomy. Prognostic performance of NWU improved after excluding patients with hemorrhagic transformation and thrombectomy (adjusted odds ratio, 0.90 [95% CI, 0.80-1.02]; P=0.10). CONCLUSIONS: NWU correlated poorly with conventional markers of cerebral edema and was not associated with clinical outcome in the presence of hemorrhagic transformation and thrombectomy. Measuring NWU postthrombectomy requires validation before implementation into clinical research. At present, the use of NWU should be limited to baseline CT, or follow-up CT only in patients without hemorrhagic transformation or treatment with thrombectomy.

Comparison of Three Scores of Collateral Status for Their Association With Clinical Outcome: The HERMES Collaboration.

BACKGROUND: Leptomeningeal collateral status on baseline computed tomographic angiography (CTA) is associated with clinical outcome after acute ischemic stroke treatment. However, assessment of collateral status is not uniform. To compare 3 different CTA collateral scores (CS) and imaging techniques about their association with clinical outcome. METHODS: Pooled analysis of patient-level data from the Highly Effective Reperfusion Using Multiple Endovascular Devices collaboration. Patients with large vessel occlusion from 7 randomized controlled trials that compared endovascular thrombectomy with standard medical care were included. Three different CS (Tan CS, regional CS [rCS], and regional Alberta Stroke Program Early CT Score CS) and 2 imaging techniques (single-phase [sCTA] and multiphase/dynamic CTA) were evaluated. Functional independence (modified Rankin Scale score 0-2) at 3 months poststroke was the primary outcome. Furthermore, we assessed the effect of sCTA image acquisition time on collateral status assessment using an adjusted ordinal logistic regression model to obtain predicted values for the trichotomized rCS. RESULTS: Among 1147 pooled patients, 948 (82.7%) had sCTA and 199 (17.3%) multiphase/dynamic CTA as baseline angiography. With all 3 collateral scales, better CSs were associated with better 3-month functional outcome. With sCTA images, the rCS (area under the curve [AUC] 0.63) and regional Alberta Stroke Program Early CT Score CS (AUC 0.62) better predicted functional outcome than the Tan CS (AUC 0.60, respectively; P<0.001 and P=0.02). With multiphase/dynamic CTA images, all collateral scales performed similarly in predicting functional outcome (rCS [AUC 0.61]; regional Alberta Stroke Program Early CT Score CS [AUC 0.61] versus Tan CS [AUC 0.61], respectively; P=0.93 and P=0.91). Overall, no endovascular thrombectomy treatment effect modification by collateral status (rCS) was demonstrated (P=0.41). sCTA timing independently influenced CS assessment. On earlier timed sCTA, the predicted proportions of scans with poor collaterals was higher and vice versa. CONCLUSIONS: In this data set of highly selected patients with stroke, using a regional CS on sCTA likely allows for the most accurate prediction of functional outcome while on time-resolved CTA, the type of CS did not matter. Patients across all collateral grades benefit from endovascular thrombectomy. sCTA timing independently influenced CS assessment.