Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial.

BACKGROUND: The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized. METHODS: SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined. RESULTS: Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77). CONCLUSIONS: ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

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.

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.

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial.

Importance: Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT). Objective: To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes. Design, Setting, and Participants: This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024. Interventions: EVT vs MM. Main Outcomes and Measures: Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication. Results: A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80). Conclusions and Relevance: Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport. Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Transradial versus transfemoral access for mechanical thrombectomy in acute ischemic stroke: A retrospective cohort study.

BACKGROUND: The objective of this study was to compare procedural and clinical outcomes in patients with acute ischemic stroke (AIS) treated via transradial access (TRA) mechanical thrombectomy (MT) versus conventional transfemoral access (TFA). METHODS: We performed a retrospective analysis of consecutive patients with AIS treated with TRA versus TFA MT at our tertiary comprehensive stroke center. Access choice was individualized based on occlusion site, aortic and arch anatomy. Outcomes were extracted from our institutional stroke registry and included procedural time, Thrombolysis in Cerebral Infarction (TICI) reperfusion score, NIHSS, 90-day mRS and 90-day mortality. Comparisons were performed using Student t-Test and Fischer's exact test as appropriate. RESULTS: 175 mechanical thrombectomies were performed during the study interval; 39 (22%) were performed via TRA and 136 (79%) TFA. Access to reperfusion time was 36.3 ± 24.5 minutes in the TRA group and 21.9 ± 17.6 in the TFA group (p<0.001). The proportion of patients with a TICI reperfusion score of 2b or 3 was similar in both groups (TRA: 34 (87%) vs. TFA: 121 (89%) p=0.559. The median 90-day mRS was similar between both groups (p=0.170), as was the 90-day mortality (p = 0.509). CONCLUSIONS: While TFA is faster in our cohort, TFA and TRA are both safe and effective for MT in acute ischemic stroke. While TFA remains mainstay, TRA can be valuable in variant anatomy despite its technical limitations. Individualizing access based on advanced imaging and patient factors may improve practice; however, updates in catheter and access technology are necessary to optimize outcomes with TRA.

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.).

Society of NeuroInterventional Surgery: position statement on pregnancy and parental leave for physicians practicing neurointerventional surgery.

BACKGROUND: The aim of this article is to outline a position statement on pregnancy and parental leave for physicians practicing neurointerventional surgery. METHODS: We performed a structured literature review regarding parental leave policies in neurointerventional surgery and related fields. The recommendations resulted from discussion among the authors, and additional input from the Women in NeuroIntervention Committee, the full Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee, and the SNIS Board of Directors. RESULTS: Some aspects of workplace safety during pregnancy are regulated by the US Nuclear Regulatory Commission. Other aspects of the workplace and reasonable job accommodations are legally governed by the Family and Medical Leave Act of 1993, the Affordable Care Act of 2010 and the Fair Labor Standards Act of 1938, Americans with Disabilities Act of 1990, Title IX of the Education Amendments of 1972, Title VII of the Civil Rights Act of 1964 as well as rights and protections put forth by the Occupational Safety and Health Administration as part of the United States Department of Labor. Family friendly policies have been associated not only with improved job satisfaction but also with improved parental and infant outcomes. Secondary effects of such accommodations are to increase the number of women within the specialty. CONCLUSIONS: SNIS supports a physician's ambition to have a family as well as start, develop, and maintain a career in neurointerventional surgery. Legal and regulatory mandates and family friendly workplace policies should be considered when institutions and individual practitioners approach the issue of childbearing in the context of a career in neurointerventional surgery.

Sex differences in endovascular thrombectomy outcomes in large vessel occlusion: a propensity-matched analysis from the SELECT study.

BACKGROUND: Sex disparities in acute ischemic stroke outcomes are well reported with IV thrombolysis. Despite several studies, there is still a lack of consensus on whether endovascular thrombectomy (EVT) outcomes differ between men and women. OBJECTIVE: To compare sex differences in EVT outcomes at 90-day follow-up and assess whether progression in functional status from discharge to 90-day follow-up differs between men and women. METHODS: From the Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT) prospective cohort study (2016-2018), adult men and women (≥18 years) with anterior circulation large vessel occlusion (internal carotid artery, middle cerebral artery M1/M2) treated with EVT up to 24 hours from last known well were matched using propensity scores. Discharge and 90-day modified Rankin Scale (mRS) scores were compared between men and women. Furthermore, we evaluated the improvement in mRS scores from discharge to 90 days in men and women using a repeated-measures, mixed-effects regression model. RESULTS: Of 285 patients, 139 (48.8%) were women. Women were older with median (IQR) age 69 (57-81) years vs 64.5 (56-75), p=0.044, had smaller median perfusion deficits (Tmax >6 s) 109 vs 154 mL (p<0.001), and had better collaterals on CT angiography and CT perfusion but similar ischemic core size (relative cerebral blood flow <30%: 7.6 (0-25.2) vs 11.4 (0-38) mL, p=0.22). In 65 propensity-matched pairs, despite similar discharge functional independence rates (women: 42% vs men: 48%, aOR=0.55, 95% CI 0.18 to 1.69, p=0.30), women exhibited worse 90-day functional independence rates (women: 46% vs men: 60%, aOR=0.41, 95% CI 0.16 to 1.00, p=0.05). The reduction in mRS scores from discharge to 90 days also demonstrated a significantly larger improvement in men (discharge 2.49 and 90 days 1.88, improvement 0.61) than in women (discharge 2.52 and 90 days 2.44, improvement 0.08, p=0.036). CONCLUSION: In a propensity-matched cohort from the SELECT study, women had similar discharge outcomes as men following EVT, but the improvement from discharge to 90 days was significantly worse in women, suggesting the influence of post-discharge factors. Further exploration of this phenomenon to identify target interventions is warranted. TRIAL REGISTRATION NUMBER: NCT02446587.

Assistance from Automated ASPECTS Software Improves Reader Performance.

PURPOSE: To compare physicians' ability to read Alberta Stroke Program Early CT Score (ASPECTS) in patients with a large vessel occlusion within 6 hours of symptom onset when assisted by a machine learning-based automatic software tool, compared with their unassisted score. MATERIALS AND METHODS: 50 baseline CT scans selected from two prior studies (CRISP and GAMES-RP) were read by 3 experienced neuroradiologists who were provided access to a follow-up MRI. The average ASPECT score of these reads was used as the reference standard. Two additional neuroradiologists and 6 non-neuroradiologist readers then read the scans both with and without assistance from the software reader-augmentation program and reader improvement was determined. The primary hypothesis was that the agreement between typical readers and the consensus of 3 expert neuroradiologists would be improved with software augmented vs. unassisted reads. Agreement was based on the percentage of the individual ASPECT regions (50 cases, 10 regions each; N=500) where agreement was achieved. RESULTS: Typical non-neuroradiologist readers agreed with the expert consensus read in 72% of the 500 ASPECTS regions, evaluated without software assistance. The automated software alone agreed in 77%. When the typical readers read the scan in conjunction with the software, agreement improved to 78% (P<0.0001, test of proportions). The software program alone achieved correlations for total ASPECT scores that were similar to the expert readers who had access to the follow-up MRI scan to help enhance the quality of their reads. CONCLUSION: Typical readers had statistically significant improvement in their scoring of scans when the scan was read in conjunction with the automated software, achieving agreement rates that were comparable to neuroradiologists.

The Safety and Feasibility of Mechanical Thrombectomy for Mild Acute Ischemic Stroke With Large Vessel Occlusion.

BACKGROUND: Prospective evidence to support mechanical thrombectomy (MT) for mild ischemic stroke with large vessel occlusion (LVO) is lacking. There is uncertainty about using an invasive procedure in patients with mild symptoms. OBJECTIVE: To evaluate the safety and feasibility of MT in patients with mild symptoms and LVO. METHODS: Our single-arm prospective pilot study recruited patients with LVO and initial National Institute of Health Stroke Scale (NIHSS) <6, who underwent standard MT. Primary safety endpoints were symptomatic intracerebral hemorrhage (sICH), and/or worsening NIHSS by ≥4 points. Secondary endpoints included angiographic recanalization, NIHSS change, final infarct volume, and modified Rankin score (mRS). RESULTS: We enrolled 20 patients (mean age 65.6 ± 12.3 yr; 45% females). Thrombolysis in Cerebral Ischemia 2B/3 thrombectomy was achieved in 95%. No patients suffered sICH. One patient (5%) had neurologic worsening within 24 h because of underlying intracranial stenosis. No other complications or safety concerns were identified. Median NIHSS was significantly better at discharge (0.5, P = .007) and at last follow-up (0, P < .001) than before treatment (3). Mean post vs preintervention infarct volumes were small without significant difference (1.2 ml, P = .434). Most patients (85%) were discharged directly home. Excellent clinical outcome (mRS 0-1) at last follow-up was seen in 95% of patients. CONCLUSION: This is one of the first specifically designed prospective studies showing that MT is safe and feasible in patients with low NIHSS and LVO. Chronic underlying vasculopathy may be a challenging dilemma. We observed excellent clinical and radiographic outcomes, but randomized controlled trials are needed to demonstrate the efficacy of MT in this unique cohort.

Early post-Humanitarian Device Exemption experience with the Neuroform Atlas stent.

INTRODUCTION: The low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with the Atlas stent in our institution within the first year after its HDE approval. METHODS: Our retrospective chart review identified patients treated with the Atlas stent. We analyzed the patient demographics, aneurysm characteristics, stent parameters and configuration, complications, angiographic, and clinical outcomes at discharge. RESULTS: From January to December 2018, 76 Atlas stents were deployed in 58 patients (average 1.3 stents/patient). Median patient age was 63.5 (IQR 56-71) years. Fifty-six (96.6%) patients had elective embolization of unruptured aneurysms, while two (3.4%) patients underwent embolization of a ruptured aneurysm within 2 weeks of subarachnoid hemorrhage. Forty (69.0%) patients were treated with a single stent, 15 (25.9%) with a Y-stent, and three (5.2%) with X-stent configuration. All stent deployments were technically successful. Most stents (82.9%) were the smallest 3 mm diameter devices. Procedural complications included transient stent-associated thrombosis in three (5.2%) patients and aneurysm rupture in one (1.7%). None had distal embolization, associated cerebral infarction, or permanent neurological deficits. Immediate Raymond-Roy 1 occlusion was achieved in 41 (70.7%) patients. Median hospital length of stay for elective aneurysm embolization was 1 day. Excellent outcomes with median National Institute of Health Stroke Scale score 0 (IQR 0-0) and modified Rankin Score 0 (IQR 0-1) were seen for elective patients at discharge. CONCLUSION: The Neuroform Atlas stent provided a reliable technical and safety profile for the treatment of intracranial wide-neck aneurysms. Further experience is needed to determine long-term durability and safety of this device.

Time From Imaging to Endovascular Reperfusion Predicts Outcome in Acute Stroke.

BACKGROUND AND PURPOSE: This study aims to describe the relationship between computed tomographic (CT) perfusion (CTP)-to-reperfusion time and clinical and radiological outcomes, in a cohort of patients who achieve successful reperfusion for acute ischemic stroke. METHODS: We included data from the CRISP (Computed Tomographic Perfusion to Predict Response in Ischemic Stroke Project) in which all patients underwent a baseline CTP scan before endovascular therapy. Patients were included if they had a mismatch on their baseline CTP scan and achieved successful endovascular reperfusion. Patients with mismatch were categorized into target mismatch and malignant mismatch profiles, according to the volume of their Tmax >10s lesion volume (target mismatch, <100 mL; malignant mismatch, >100 mL). We investigated the impact of CTP-to-reperfusion times on probability of achieving functional independence (modified Rankin Scale, 0-2) at day 90 and radiographic outcomes at day 5. RESULTS: Of 156 included patients, 108 (59%) had the target mismatch profile, and 48 (26%) had the malignant mismatch profile. In patients with the target mismatch profile, CTP-to-reperfusion time showed no association with functional independence (P=0.84), whereas in patients with malignant mismatch profile, CTP-to-reperfusion time was strongly associated with lower probability of functional independence (odds ratio, 0.08; P=0.003). Compared with patients with target mismatch, those with the malignant mismatch profile had significantly more infarct growth (90 [49-166] versus 43 [18-81] mL; P=0.006) and larger final infarct volumes (110 [61-155] versus 48 [21-99] mL; P=0.001). CONCLUSIONS: Compared with target mismatch patients, those with the malignant profile experience faster infarct growth and a steeper decline in the odds of functional independence, with longer delays between baseline imaging and reperfusion. However, this does not exclude the possibility of treatment benefit in patients with a malignant profile.

Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging.

BACKGROUND: Thrombectomy is currently recommended for eligible patients with stroke who are treated within 6 hours after the onset of symptoms. METHODS: We conducted a multicenter, randomized, open-label trial, with blinded outcome assessment, of thrombectomy in patients 6 to 16 hours after they were last known to be well and who had remaining ischemic brain tissue that was not yet infarcted. Patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion, an initial infarct size of less than 70 ml, and a ratio of the volume of ischemic tissue on perfusion imaging to infarct volume of 1.8 or more were randomly assigned to endovascular therapy (thrombectomy) plus standard medical therapy (endovascular-therapy group) or standard medical therapy alone (medical-therapy group). The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at day 90. RESULTS: The trial was conducted at 38 U.S. centers and terminated early for efficacy after 182 patients had undergone randomization (92 to the endovascular-therapy group and 90 to the medical-therapy group). Endovascular therapy plus medical therapy, as compared with medical therapy alone, was associated with a favorable shift in the distribution of functional outcomes on the modified Rankin scale at 90 days (odds ratio, 2.77; P<0.001) and a higher percentage of patients who were functionally independent, defined as a score on the modified Rankin scale of 0 to 2 (45% vs. 17%, P<0.001). The 90-day mortality rate was 14% in the endovascular-therapy group and 26% in the medical-therapy group (P=0.05), and there was no significant between-group difference in the frequency of symptomatic intracranial hemorrhage (7% and 4%, respectively; P=0.75) or of serious adverse events (43% and 53%, respectively; P=0.18). CONCLUSIONS: Endovascular thrombectomy for ischemic stroke 6 to 16 hours after a patient was last known to be well plus standard medical therapy resulted in better functional outcomes than standard medical therapy alone among patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion and a region of tissue that was ischemic but not yet infarcted. (Funded by the National Institute of Neurological Disorders and Stroke; DEFUSE 3 ClinicalTrials.gov number, NCT02586415 .).

A multicenter randomized controlled trial of endovascular therapy following imaging evaluation for ischemic stroke (DEFUSE 3).

Rationale Early reperfusion in patients experiencing acute ischemic stroke is effective in patients with large vessel occlusion. No randomized data are available regarding the safety and efficacy of endovascular therapy beyond 6 h from symptom onset. Aim The aim of the study is to demonstrate that, among patients with large vessel anterior circulation occlusion who have a favorable imaging profile on computed tomography perfusion or magnetic resonance imaging, endovascular therapy with a Food and Drug Administration 510 K-cleared mechanical thrombectomy device reduces the degree of disability three months post stroke. Design The study is a prospective, randomized, multicenter, phase III, adaptive, blinded endpoint, controlled trial. A maximum of 476 patients will be randomized and treated between 6 and 16 h of symptom onset. Procedures Patients undergo imaging with computed tomography perfusion or magnetic resonance diffusion/perfusion, and automated software (RAPID) determines if the Target Mismatch Profile is present. Patients who meet both clinical and imaging selection criteria are randomized 1:1 to endovascular therapy plus medical management or medical management alone. The individual endovascular therapist chooses the specific device (or devices) employed. Study outcomes The primary endpoint is the distribution of scores on the modified Rankin Scale at day 90. The secondary endpoint is the proportion of patients with modified Rankin Scale 0-2 at day 90 (indicating functional independence). Analysis Statistical analysis for the primary endpoint will be conducted using a normal approximation of the Wilcoxon-Mann-Whitney test (the generalized likelihood ratio test).

Computed tomographic perfusion to Predict Response to Recanalization in ischemic stroke.

OBJECTIVE: To assess the utility of computed tomographic (CT) perfusion for selection of patients for endovascular therapy up to 18 hours after symptom onset. METHODS: We conducted a multicenter cohort study of consecutive acute stroke patients scheduled to undergo endovascular therapy within 90 minutes after a baseline CT perfusion. Patients were classified as "target mismatch" if they had a small ischemic core and a large penumbra on their baseline CT perfusion. Reperfusion was defined as >50% reduction in critical hypoperfusion between the baseline CT perfusion and the 36-hour follow-up magnetic resonance imaging. RESULTS: Of the 201 patients enrolled, 190 patients with an adequate baseline CT perfusion study who underwent angiography were included (mean age = 66 years, median NIH Stroke Scale [NIHSS] = 16, median time from symptom onset to endovascular therapy = 5.2 hours). Rate of reperfusion was 89%. In patients with target mismatch (n = 131), reperfusion was associated with higher odds of favorable clinical response, defined as an improvement of ≥8 points on the NIHSS (83% vs 44%; p = 0.002, adjusted odds ratio [OR] = 6.6, 95% confidence interval [CI] = 2.1-20.9). This association did not differ between patients treated within 6 hours (OR = 6.4, 95% CI = 1.5-27.8) and those treated > 6 hours after symptom onset (OR = 13.7, 95% CI = 1.4-140). INTERPRETATION: The robust association between endovascular reperfusion and good outcome among patients with the CT perfusion target mismatch profile treated up to 18 hours after symptom onset supports a randomized trial of endovascular therapy in this patient population. Ann Neurol 2017;81:849-856.