Trial of Endovascular Thrombectomy for Large Ischemic Strokes.

BACKGROUND: Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS: We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS: The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS: Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial.

BACKGROUND: Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients. METHODS: SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed. FINDINGS: The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]). INTERPRETATION: In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up. FUNDING: Stryker Neurovascular.

Cost-Effectiveness of Endovascular Thrombectomy in Patients with Large Ischemic Stroke.

OBJECTIVES: Whereas highly cost-effective and cost-saving for patients with small infarcts, whether endovascular thrombectomy (EVT) remains cost-effective in patients with extensive ischemic injury is uncertain. METHODS: We conducted a model-based cost-effectiveness analysis from the United States, Australian, and Spanish societal perspectives, using a 7-state Markov model, with each state defined by the modified Rankin Scale (mRS) score. Initial probabilities at 3 months were derived from the SELECT2 trial. All other model inputs, including transition probabilities, health care and non-health care costs, and utility weights, were sourced from published literature and government websites. Our analysis included extensive sensitivity and subgroup analyses. RESULTS: EVT in patients with large ischemic stroke improved health outcomes and was associated with lower costs from a societal viewpoint. EVT was cost-effective with a mean between-group difference of 1.24 quality-adjusted life years (QALYs), and a cost-saving of $23,409 in the United States, $10,691 in Australia, and $30,036 in Spain, in addition to uncosted benefits in productivity for patients and carers. Subgroup analyses were directionally consistent with the overall population, notably with preserved cost-effectiveness in older patients (≥ 70 years) and those with more severe strokes (National Institutes of Health Stroke Scale [NIHSS] ≥ 20). Sensitivity analyses were largely consistent with the base-case results. INTERPRETATION: EVT demonstrated cost-effectiveness in patients with large core across different settings in the United States, Australia, and Spain, including older patients and those with more severe strokes. These results further support adaptation of systems of care to accommodate the expansion of thrombectomy eligibility to patients with large cores and maximize EVT benefits. ANN NEUROL 2024.

Rescue Therapy for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Pooled Analysis of the Society of Vascular and Interventional Neurology Registry.

OBJECTIVE: We aimed to evaluate the association between rescue therapy (RT) and functional outcomes compared to medical management (MM) in patients presenting after failed mechanical thrombectomy (MT). METHODS: This cross-sectional study utilized prospectively collected and maintained data from the Society of Vascular and Interventional Neurology Registry, spanning from 2011 to 2021. The cohort comprised patients with large vessel occlusions (LVOs) with failed MT. The primary outcome was the shift in the degree of disability, as gauged by the modified Rankin Scale (mRS) at 90 days. Additional outcomes included functional independence (90-day mRS score of 0-2), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: Of a total of 7,018 patients, 958 presented failed MT and were included in the analysis. The RT group comprised 407 (42.4%) patients, and the MM group consisted of 551 (57.5%) patients. After adjusting for confounders, the RT group showed a favorable shift in the overall 90-day mRS distribution (adjusted common odds ratio = 1.79, 95% confidence interval [CI] = 1.32-2.45, p < 0.001) and higher rates of functional independence (RT: 28.8% vs MM: 15.7%, adjusted odds ratio [aOR] = 1.93, 95% CI = 1.21-3.07, p = 0.005) compared to the MM group. RT also showed lower rates of sICH (RT: 3.8% vs MM: 9.1%, aOR = 0.52, 95% CI = 0.28-0.97, p = 0.039) and 90-day mortality (RT: 33.4% vs MM: 45.5%, aOR = 0.61, 95% CI = 0.42-0.89, p = 0.009). INTERPRETATION: Our findings advocate for the utilization of RT as a potential treatment strategy for cases of LVO resistant to first-line MT techniques. Prospective studies are warranted to validate these observations and optimize the endovascular approach for failed MT patients. ANN NEUROL 2024;96:343-355.

Anticoagulation Use and Endovascular Thrombectomy in Patients with Large Core Stroke: A Secondary Analysis of the SELECT2 Trial.

Endovascular thrombectomy (EVT) safety and efficacy in patients with large core infarcts receiving oral anticoagulants (OAC) are unknown. In the SELECT2 trial (NCT03876457), 29 of 180 (16%; vitamin K antagonists 15, direct OACs 14) EVT, and 18 of 172 (10%; vitamin K antagonists 3, direct OACs 15) medical management (MM) patients reported OAC use at baseline. EVT was not associated with better clinical outcomes in the OAC group (EVT 6 [4-6] vs MM 5 [4-6], adjusted generalized odds ratio 0.89 [0.53-1.50]), but demonstrated significantly better outcomes in patients without OAC (EVT 4 [3-6] vs MM 5 [4-6], adjusted generalized odds ratio 1.87 [1.45-2.40], p = 0.02). The OAC group had higher comorbidities, including atrial fibrillation (70% vs 17%), congestive heart failure (28% vs 10%), and hypertension (87% vs 72%), suggesting increased frailty. However, the results were consistent after adjustment for these comorbidities, and was similar regardless of the type of OACs used. Whereas any hemorrhage rates were higher in the OAC group receiving EVT (86% in OAC vs 70% in no OAC), no parenchymal hemorrhage or symptomatic intracranial hemorrhage were observed with OAC use in both the EVT and MM arms. Although we did not find evidence that the effect was due to excess hemorrhage or confounded by underlying cardiac disease or older age, OAC use alone should not exclude patients from receiving EVT. Baseline comorbidities and ischemic injury extent should be considered while making individualized treatment decisions. ANN NEUROL 2024;96:887-894.

Mechanical Thrombectomy Global Access For Stroke (MT-GLASS): A Mission Thrombectomy (MT-2020 Plus) Study.

BACKGROUND: Despite the well-established potent benefit of mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke, access to MT has not been studied globally. We conducted a worldwide survey of countries on 6 continents to define MT access (MTA), the disparities in MTA, and its determinants on a global scale. METHODS: Our survey was conducted in 75 countries through the Mission Thrombectomy 2020+ global network between November 22, 2020, and February 28, 2021. The primary end points were the current annual MTA, MT operator availability, and MT center availability. MTA was defined as the estimated proportion of patients with LVO receiving MT in a given region annually. The availability metrics were defined as ([current MT operators×50/current annual number of estimated thrombectomy-eligible LVOs]×100 = MT operator availability) and ([current MT centers×150/current annual number of estimated thrombectomy-eligible LVOs]×100= MT center availability). The metrics used optimal MT volume per operator as 50 and an optimal MT volume per center as 150. Multivariable-adjusted generalized linear models were used to evaluate factors associated with MTA. RESULTS: We received 887 responses from 67 countries. The median global MTA was 2.79% (interquartile range, 0.70-11.74). MTA was <1.0% for 18 (27%) countries and 0 for 7 (10%) countries. There was a 460-fold disparity between the highest and lowest nonzero MTA regions and low-income countries had 88% lower MTA compared with high-income countries. The global MT operator availability was 16.5% of optimal and the MT center availability was 20.8% of optimal. On multivariable regression, country income level (low or lower-middle versus high: odds ratio, 0.08 [95% CI, 0.04-0.12]), MT operator availability (odds ratio, 3.35 [95% CI, 2.07-5.42]), MT center availability (odds ratio, 2.86 [95% CI, 1.84-4.48]), and presence of prehospital acute stroke bypass protocol (odds ratio, 4.00 [95% CI, 1.70-9.42]) were significantly associated with increased odds of MTA. CONCLUSIONS: Access to MT on a global level is extremely low, with enormous disparities between countries by income level. The significant determinants of MT access are the country's per capita gross national income, prehospital LVO triage policy, and MT operator and center availability.

Mechanical Thrombectomy Workshops Improve Procedural Knowledge and Skills Among Neurointerventional Teams in Low- to Middle-Income Countries.

BACKGROUND: While mechanical thrombectomy (MT) is proven to be lifesaving and disability sparing, there remains a disparity in its access in low- to middle-income countries. We hypothesized that team-based MT workshops would improve MT knowledge and skills. METHODS: We designed a 22-hour MT workshop, conducted as 2 identical events: in English (Jamaica, January 2022) and in Spanish (Dominican Republic, May 2022). The workshops included participating neurointerventional teams (practicing neurointerventionalists, neurointerventional nurses, and technicians) focused on acute stroke due to large vessel occlusion. The course faculty led didactic and hands-on components, covering topics from case selection and postoperative management to device technology and MT surgical techniques. Attendees were evaluated on stroke knowledge and MT skills before and after the course using a multiple choice exam and simulated procedures utilizing flow models under fluoroscopy, respectively. Press conferences for public education with invited government officials were included to raise stroke awareness. RESULTS: Twenty-two physicians and their teams from 8 countries across the Caribbean completed the didactic and hands-on training. Overall test scores (n=18) improved from 67% to 85% (P<0.002). Precourse and postcourse hands-on assessments demonstrated reduced time to completion from 36.5 to 21.1 minutes (P<0.001). All teams showed an improvement in measures of good MT techniques, with 39% improvement in complete reperfusion. Eight teams achieved a Thrombolysis in Cerebral Infarction score of 3 on pre-course versus 15 of 18 teams on post-course. There was a significant reduction in total potentially dangerous maneuvers (70% pre versus 20% post; P<0.002). Universally, the workshop was rated as satisfactory and likely to change practice in 93% Dominican Republic and 75% Jamaica. CONCLUSIONS: A team-based hands-on simulation approach to MT training is novel, feasible, and effective in improving procedural skills. Participants viewed these workshops as practice-changing and instrumental in creating a pathway for increasing access to MT in low- to middle-income countries.

Endovascular Versus Medical Management in Distal Medium Vessel Occlusion Stroke: The DUSK Study.

BACKGROUND: Endovascular treatment (EVT) is part of the usual care for proximal vessel occlusion strokes. However, the safety and effectiveness of EVT for distal medium vessel occlusions remain unclear. We sought to compare the clinical outcomes of EVT to medical management (MM) for isolated distal medium vessel occlusions. METHODS: This is a retrospective analysis of prospectively collected data from seven comprehensive stroke centers. Patients were included if they had isolated distal medium vessel occlusion strokes due to middle cerebral artery M3/M4, anterior cerebral artery A2/A3, or posterior cerebral artery P1/P2 segments. Patients treated with EVT or MM were compared with multivariable logistic regression and inverse probability of treatment weighting. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included 90-day good (mRS score, 0-2) and excellent (mRS score, 0-1) outcomes. Safety measures included symptomatic intracranial hemorrhage and 90-day mortality. RESULTS: A total of 321 patients were included in the analysis (EVT, 179; MM, 142; 40.8% treated with intravenous thrombolysis). In the inverse probability of treatment weighting model, there were no significant differences between EVT and MM in terms of the overall degree of disability (mRS ordinal shift; adjusted odds ratio [aOR], 1.25 [95% CI, 0.95-1.64]; P=0.110), rates of good (mRS score, 0-2; aOR, 1.32 [95% CI, 0.97-1.80]; P=0.075) and excellent (aOR, 1.32 [95% CI, 0.94-1.85]; P=0.098) outcomes, or mortality (aOR, 1.20 [95% CI, 0.78-1.85]; P=0.395) at 90 days. The multivariable regression model showed similar findings. Moreover, there was no difference between EVT and MM in rates of symptomatic intracranial hemorrhage in the multivariable regression model (aOR, 0.57 [95% CI, 0.21-1.58]; P=0.277), but the inverse probability of treatment weighting model showed a lower likelihood of symptomatic intracranial hemorrhage (aOR, 0.46 [95% CI, 0.24-0.85]; P=0.013) in the EVT group. CONCLUSIONS: This multicenter study failed to demonstrate any significant outcome differences among patients with isolated distal medium vessel occlusions treated with EVT versus MM. These findings reinforce clinical equipoise. Randomized clinical trials are ongoing and will provide more definite evidence.

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.

Mechanical Thrombectomy Access Score: A Systematic Review and Modified Delphi of Global Barriers to Endovascular Therapy.

BACKGROUND: The availability of mechanical thrombectomy (MT) for acute ischemic stroke is limited, and vast disparities exist between countries. We aim to create a MT access score to measure the drivers of access to help quantify and accelerate treatment worldwide. METHODS: We used a systematic review complemented by a modified Delphi method. In the first of 3 rounds, 4 independent investigators performed a systematic literature review using key search terms that drive MT access, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In the second round, a panel of 6 anonymous international experts selected key attributes needed for scoring. In the final round, a total of 12 attributes were selected on consensus, each given a score on a 0 to 3 scale. An ultimate MT access score (range, 0-36) was proposed as a new tool to use in identifying barriers to MT access and assist in providing an initial framework for public health interventions. RESULTS: Of 2864 abstracts screened, 121 studies were included in the final systematic review. A total of 34 attributes that potentially drive MT access were initially identified. In the final round, 12 attributes were selected by the expert panel: public awareness, emergency medical services transportation, prehospital large vessel occlusion screening, interhospital transfer policy, emergency department protocols, stroke imaging protocols, emergency department stroke expertise or telestroke availability, interventionalists, MT-capable centers, device availability, and insurance coverage. These attributes were weighted as part of the final score of 0 to 36. CONCLUSIONS: The MT access score represents the first tool to quantify barriers to global MT access. Its implementation stands not just as an academic achievement but as a beacon of hope for improving stroke care and outcomes worldwide, bringing us a step closer to bridging the gap in stroke treatment disparities.

Outcomes of Bridging Intravenous Thrombolysis Versus Endovascular Therapy Alone in Late-Window Acute Ischemic Stroke.

BACKGROUND: Studies comparing bridging intravenous thrombolysis (IVT) with direct endovascular therapy (EVT) in patients with acute ischemic stroke who present late are limited. We aimed to compare the clinical outcomes and safety of bridging IVT in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who underwent EVT 6 to 24 hours after time last known well. METHODS: We enrolled patients with anterior circulation large vessel occlusion stroke and a National Institutes of Health Stroke Scale score of ≥6 from 20 centers across 10 countries in the multicenter retrospective CLEAR study (CT for Late Endovascular Reperfusion) between January 2014 and May 2022. We used inverse probability of treatment weighting modeling adjusted for clinical and imaging confounders to compare functional outcomes, reperfusion success, symptomatic intracranial hemorrhage, and mortality between EVT patients with and without prior IVT. RESULTS: Of 5098 patients screened for eligibility, we included 2749 patients, of whom 549 received bridging IVT before EVT. The timing of IVT was not recorded. Witnessed stroke onset and transfer rates were higher in the bridging IVT group (25% versus 12% and 77% versus 55%, respectively, P value for both <0.0001), and time intervals between stroke onset and treatment were shorter (time last known well-start of EVT median 560 minutes [interquartile range, 432-791] versus 724 minutes [interquartile range, 544-912]; P<0.0001). After adjustment for confounders, there was no difference in functional outcome at 3 months (adjusted common odds ratio for modified Rankin Scale shift, 1.03 [95% CI, 0.89-1.19]; P=0.72) or successful reperfusion (adjusted odds ratio, 1.19 [95% CI, 0.81-1.75]; P=0.39). There were no safety concerns associated with bridging IVT versus direct EVT (symptomatic intracranial hemorrhage: adjusted odds ratio, 0.75 [95% CI, 0.38-1.48]; P=0.40; mortality: adjusted odds ratio, 1.14 [95% CI, 0.89-1.46]; P=0.31). Results were unchanged when the analysis was limited to patients who received IVT >6 hours after last known well. CONCLUSIONS: In patients with an anterior circulation large vessel occlusion stroke who underwent EVT 6 to 24 hours from last known well, bridging IVT was not associated with a difference in outcomes compared with direct EVT. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04096248.

Sex Differences in Outcomes of Late-Window Endovascular Stroke Therapy.

BACKGROUND: The association between sex and outcome after endovascular thrombectomy of acute ischemic stroke is unclear. The aim of this study was to compare the clinical and safety outcomes between men and women treated with endovascular thrombectomy in the late 6-to-24-hour window period. METHODS: This multicenter, retrospective observational cohort study included consecutive patients who underwent endovascular thrombectomy of anterior circulation stroke in the late window from 66 clinical sites in 10 countries from January 2014 to May 2022. The primary outcome was the 90-day ordinal modified Rankin Scale score. Secondary outcomes included 90-day functional independence (FI), return of Rankin (RoR) to prestroke baseline, FI or RoR, symptomatic intracranial hemorrhage, and mortality. Multivariable and inverse probability of treatment weighting methods were used. We explored the interaction of sex with baseline characteristics on the outcomes ordinal modified Rankin Scale and FI or RoR. RESULTS: Of 1932 patients, 1055 were women and 877 were men. Women were older (77 versus 69 years), had higher rates of atrial fibrillation, hypertension, and greater prestroke disability, but there was no difference in baseline National Institutes of Health Stroke Scale score. Inverse probability of treatment weighting analysis showed no difference between women and men in ordinal modified Rankin Scale (odds ratio, 0.98 [95% CI, 0.79-1.21]), FI or RoR (odds ratio, 0.98 [95% CI, 0.78-1.22]), severe disability or mortality (odds ratio, 0.99 [95% CI, 0.80-1.23]). The multivariable analysis of the above end points was concordant. There were no interactions between baseline characteristics and sex on the outcomes of ordinal modified Rankin Scale and FI or RoR. CONCLUSIONS: In late presenting patients with anterior circulation stroke treated with endovascular thrombectomy in the 6 to 24-hour window, there was no difference in clinical or safety outcomes between men and women.

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.

Mediation of Successful Reperfusion Effect through Infarct Growth and Cerebral Edema: A Pooled, Patient-Level Analysis of EXTEND-IA Trials and SELECT Prospective Cohort.

OBJECTIVE: Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship. METHODS: In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift. RESULTS: A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (ß = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results. INTERPRETATION: In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023;93:793-804.

Impact of Therapeutic Interventions on Cerebral Autoregulatory Function Following Severe Traumatic Brain Injury: A Secondary Analysis of the BOOST-II Study.

BACKGROUND: The Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II randomized controlled trial used a tier-based management protocol based on brain tissue oxygen (PbtO2) and intracranial pressure (ICP) monitoring to reduce brain tissue hypoxia after severe traumatic brain injury. We performed a secondary analysis to explore the relationship between brain tissue hypoxia, blood pressure (BP), and interventions to improve cerebral perfusion pressure (CPP). We hypothesized that BP management below the lower limit of autoregulation would lead to cerebral hypoperfusion and brain tissue hypoxia that could be improved with hemodynamic augmentation. METHODS: Of the 119 patients enrolled in the Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase II trial, 55 patients had simultaneous recordings of arterial BP, ICP, and PbtO2. Autoregulatory function was measured by interrogating changes in ICP and PbtO2 in response to fluctuations in CPP using time-correlation analysis. The resulting autoregulatory indices (pressure reactivity index and oxygen reactivity index) were used to identify the "optimal" CPP and limits of autoregulation for each patient. Autoregulatory function and percent time with CPP outside personalized limits of autoregulation were calculated before, during, and after all interventions directed to optimize CPP. RESULTS: Individualized limits of autoregulation were computed in 55 patients (mean age 38 years, mean monitoring time 92 h). We identified 35 episodes of brain tissue hypoxia (PbtO2 < 20 mm Hg) treated with CPP augmentation. Following each intervention, mean CPP increased from 73 ± 14 mm Hg to 79 ± 17 mm Hg (p = 0.15), and mean PbtO2 improved from 18.4 ± 5.6 mm Hg to 21.9 ± 5.6 mm Hg (p = 0.01), whereas autoregulatory function trended toward improvement (oxygen reactivity index 0.42 vs. 0.37, p = 0.14; pressure reactivity index 0.25 vs. 0.21, p = 0.2). Although optimal CPP and limits remained relatively unchanged, there was a significant decrease in the percent time with CPP below the lower limit of autoregulation in the 60 min after compared with before an intervention (11% vs. 23%, p = 0.05). CONCLUSIONS: Our analysis suggests that brain tissue hypoxia is associated with cerebral hypoperfusion characterized by increased time with CPP below the lower limit of autoregulation. Interventions to increase CPP appear to improve autoregulation. Further studies are needed to validate the importance of autoregulation as a modifiable variable with the potential to improve outcomes.

Thrombectomy for Stroke With Large Infarct on Noncontrast CT: The TESLA Randomized Clinical Trial.

Importance: Recent large infarct thrombectomy trials used heterogeneous imaging modalities and time windows for patient selection. Noncontrast computed tomographic (CT) scan is the most common stroke imaging approach. It remains uncertain whether thrombectomy is effective for patients with large infarcts identified using noncontrast CT alone within 24 hours of stroke onset. Objective: To evaluate the effect of thrombectomy in patients with a large infarct on a noncontrast CT scan within 24 hours of onset. Design, Setting, and Participants: Open-label, blinded-end point, bayesian-adaptive randomized trial with interim analyses for early stopping (futility or success) or population enrichment, which was conducted at 47 US academic and community-based stroke thrombectomy centers. Three hundred patients presenting within 24 hours with anterior-circulation, large-vessel occlusion and large infarct on noncontrast CT scan, with Alberta Stroke Program Early CT Scores of 2 to 5, were randomized to undergo thrombectomy or usual care. Enrollment occurred July 16, 2019 to October 17, 2022; final follow-up, January 25, 2023. Intervention: The intervention patients (n = 152) underwent endovascular treatment using standard thrombectomy devices and usual medical care. Control patients (n = 148) underwent usual medical care alone. Main Outcomes and Measures: The primary efficacy end point was improvement in 90-day functional outcome measured using mean utility-weighted modified Rankin Scale (UW-mRS) scores (range, 0 [death or severe disability] to 10 [no symptoms]; minimum clinically important difference, 0.3). A bayesian model determined the posterior probability that the intervention would be superior to usual care; statistical significance was a 1-sided posterior probability of .975 or more. The primary adverse event end point was 90-day mortality; secondary adverse event end points included symptomatic intracranial hemorrhage and radiographic intracranial hemorrhage. Results: The trial enrolled 300 patients (152 intervention, 148 control; 138 females [46%]; median age, 67 years), without early stopping or enrichment; 297 patients completed the 90-day follow-up. The mean (SD) 90-day UW-mRS score was 2.93 (3.39) for the intervention group vs 2.27 (2.98) for the control group with an adjusted difference of 0.63 (95% credible interval [CrI], -0.09 to 1.34; posterior probability for superiority of thrombectomy, .96). The 90-day mortality was similar between groups: 35.3% (53 of 150) for the intervention group vs 33.3% (49 of 147) for the control group. Six of 151 patients (4.0%) in the intervention group and 2 of 149 (1.3%) in the control group experienced 24-hour symptomatic intracranial hemorrhage. Fourteen patients of 148 (9.5%) in the intervention group vs 4 of 146 (2.7%) in the control group experienced parenchymal hematoma type 1 hemorrhages; 14 (9.5%) in the intervention group vs 5 (3.4%) in the control group experienced parenchymal hematoma type 2 hemorrhages; and 24 (16.2%) in the intervention group vs 9 (6.2%) in the control group experienced subarachnoid hemorrhages. Conclusions and Relevance: Among patients with a large infarct on noncontrast CT within 24 hours, thrombectomy did not demonstrate improvement in functional outcomes. But the width of the credible interval around the effect estimate includes the possibility of both no important effect and a clinically relevant benefit, so the potential role of thrombectomy with this imaging approach and time window will likely require additional study. Trial Registration: ClinicalTrials.gov Identifier: NCT03805308.

Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles.

Importance: Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain. Objective: To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect. Design, Setting, and Participants: An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022. Intervention: EVT vs MM. Main Outcomes and Measures: Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI. Results: Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled. Conclusion and Relevance: In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased. Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Safety Outcomes of Mechanical Thrombectomy Versus Combined Thrombectomy and Intravenous Thrombolysis in Tandem Lesions.

BACKGROUND: We aimed to describe the safety and efficacy of mechanical thrombectomy (MT) with or without intravenous thrombolysis (IVT) for patients with tandem lesions and whether using intraprocedural antiplatelet therapy influences MT's safety with IVT treatment. METHODS: This is a subanalysis of a pooled, multicenter cohort of patients with acute anterior circulation tandem lesions treated with MT from 16 stroke centers between January 2015 and December 2020. Primary outcomes included symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2. Additional outcomes included hemorrhagic transformation, successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b-3), complete reperfusion (modified Thrombolysis in Cerebral Infarction score 3), favorable functional outcome (90-day modified Rankin Scale score 0-2), excellent functional outcome (90-day modified Rankin Scale score 0-1), in-hospital mortality, and 90-day mortality. RESULTS: Of 691 patients, 512 were included (218 underwent IVT+MT and 294 MT alone). There was no difference in the risk of sICH (adjusted odds ratio [aOR], 1.22 [95% CI, 0.60-2.51]; P=0.583), parenchymal hematoma type 2 (aOR, 0.99 [95% CI, 0.47-2.08]; P=0.985), and hemorrhagic transformation (aOR, 0.95 [95% CI, 0.62-1.46]; P=0.817) between the IVT+MT and MT alone groups after adjusting for confounders. Administration of IVT was associated with an increased risk of sICH in patients who received intravenous antiplatelet therapy (aOR, 3.04 [95% CI, 0.99-9.37]; P=0.05). The IVT+MT group had higher odds of a 90-day modified Rankin Scale score 0 to 2 (aOR, 1.72 [95% CI, 1.01-2.91]; P=0.04). The odds of successful reperfusion, complete reperfusion, 90-day modified Rankin Scale score 0 to 1, in-hospital mortality, or 90-day mortality did not differ between the IVT+MT versus MT alone groups. CONCLUSIONS: Our study showed that the combination of IVT with MT for tandem lesions did not increase the overall risk of sICH, parenchymal hematoma type 2, or overall hemorrhagic transformation independently of the cervical revascularization technique used. However, intraprocedural intravenous antiplatelet therapy during acute stent implantation might be associated with an increased risk of sICH in patients who received IVT before MT. Importantly, IVT+MT treatment was associated with a higher rate of favorable functional outcomes at 90 days.

Comparing Functional Outcomes and Safety Profiles of First-Line Aspiration Thrombectomy Versus Stentriever for Acute Basilar Artery Occlusion: Propensity Analysis of the PC-SEARCH Thrombectomy Registry.

BACKGROUND: Aspiration catheters (ASPs) and stentriever thrombectomy devices have comparable safety and efficacy in anterior circulation ischemic strokes. However, there is lack of high-quality comparative data in acute basilar artery occlusions. Our objective is to compare the outcomes and safety of ASPs and stentriever devices in acute basilar artery occlusions. METHODS: This is an analysis of the retrospectively established PC-SEARCH Thrombectomy (Posterior-Circulation Ischemic Stroke Evaluation: Analyzing Radiographic and Intraprocedural Predictors for Mechanical Thrombectomy) registry. Patients were dichotomized based on their first-line thrombectomy device (ASP and stentriever) and associated with their 90-day functional outcomes, intraprocedural metrics, and safety measures. Propensity analysis based on unequal baseline characteristics was performed. Consecutive patients with acute basilar artery occlusions who received mechanical thrombectomy were included from January 2015 to December 2021. Patients received either first-line contact aspiration or stentriever mechanical thrombectomy. Primary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale score of 0 to 3 and symptomatic intracranial hemorrhage, respectively. Secondary outcomes included puncture-recanalization times, first-pass recanalization rates, crossovers to other thrombectomy device, and neurological/hospital complications. RESULTS: Five hundred eighteen patients were included in the registry, and a total of 383 patients were included (mean [SD] age, 65.5 [15] years; 228 [59%] men) in this analysis. Of these, 219 patients were first-line ASP while 164 patients received first-line stentriever devices. Median premorbid modified Rankin Scale was zero and median presenting National Institutes of Health Stroke Scale was 17 (interquartile range, 8-26). The proportion of favorable functional outcome was similar between the 2 techniques before (47.3% versus 42.5%; odds ratio, 1.22 [95% CI, 0.78-1.89]; P=0.38) and after propensity matching (odds ratio, 1.46 [95% CI, 0.85-2.49]; P=0.17). In our propensity-matched cohorts, puncture-recanalization times (18 versus 52 minutes; P<0.01) favored first-line ASP; however, first-pass recanalization rates (43.5% versus 44.5%; P=0.90) were similar between groups. First-line ASP was associated with higher rates of crossover (22% versus 6%; P<0.01), whereas stentriever was associated with higher rates of symptomatic intracranial hemorrhage (9.8% versus 3.4%; P=0.04). CONCLUSIONS: First-line ASP and stentriever methods demonstrated similar functional outcome and recanalization rates. Stentriever methods were associated with higher rates of symptomatic intracranial hemorrhage, whereas ASPs were associated with higher rates of crossover to alternative technique in patients with acute basilar occlusions.

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.