Acute Cerebral Large Vessel Occlusion Research Articles

Application of Computed Tomography Perfusion Imaging-guided Mechanical Thrombectomy in Ischemic Stroke Patients with Large Vessel Occlusion beyond the Therapeutic Time Window.

To explore the feasibility of applying computed tomography perfusion (CTP) imaging-guided mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusion beyond the therapeutic time window. The clinical data of acute cerebral infarction patients with large vessel occlusion who were beyond the therapeutic time window and admitted to Handan Central Hospital from January 2021 to March 2022 were retrospectively analyzed. All patients were assessed by the National Institutes of Health Stroke Scale (NIHSS) and were examined by one-stop CTP imaging. The preoperative onset time of the disease was more than 6 h. Fourteen patients underwent magnetic resonance imaging examination at the same time. Fifty-four patients were retrospectively divided into two groups based on the treatment methods: the mechanical thrombectomy group had 21 patients and the conservative treatment group had 33 patients. NIHSS scoring and computed tomography scan were performed before treatment, 6 h, 24 h, 7 days, and 30 days after treatment. The NIHSS scores of the patients with acute cerebral large vessel occlusion who underwent CTP imaging-guided mechanical thrombectomy at 6 h, 24 h, 7 days, and 30 days after treatment were compared with those of the conventional treatment group. The NIHSS score of the mechanical thrombectomy group was significantly better, and the difference was statistically significant (P < 0.05). In terms of the prognosis rate and expansion rate of infarct core volume, the patients of the mechanical thrombectomy group had a better prognosis, and the difference was statistically significant (P < 0.05). Artificial intelligence-assisted CTP diagnosis can facilitate the automatic evaluation of diseases and enable quick judgments that are independent of radiologists' evaluation, but it may pose a problem in the determination of infarct core volume (either being too high or too low). It is of great significance to apply CTP imaging in guiding the mechanical thrombectomy procedure in acute stroke patients with large vessel occlusion who are beyond the therapeutic time window.

Computed Tomography Perfusion Parameters Predictive of Symptomatic Intracranial Hemorrhage After Mechanical Thrombectomy in Patients With Cerebral Large Vessel Occlusion

Background Hemorrhagic transformation after recanalization is a severe complication in patients with a large ischemic core due to cerebral large vessel occlusion. Risk assessment using perfusion imaging to predict hemorrhagic infarction has not been established. Thus, we aimed to investigate the association between perfusion imaging findings and hemorrhagic transformation in patients with acute cerebral large vessel occlusion who had undergone preoperative perfusion imaging evaluation and mechanical thrombectomy. Methods We enrolled consecutive patients who received mechanical thrombectomy after undergoing perfusion imaging for anterior large vessel occlusion from May 2019 to March 2022. The patients in whom recanalization were not achieved and who experienced procedure‐related bleeding were excluded. We investigated the predictors of symptomatic intracranial hemorrhage (sICH) by exploring preoperative perfusion imaging parameters (relative cerebral blood flow, relative cerebral blood volume, time of maximum concentration, and hypoperfusion index ratio). Results Among the 167 patients (median age 79 years, 47% female) enrolled, 63 (38%) and 14 (8%) patients had any intracranial hemorrhage and sICH (sICH group), respectively. The sICH group had a shorter puncture‐recanalization time than the non‐sICH group (median [interquartile range (IQR)]; 43 [34–55] versus 61 [37–88]; P =0.046), whereas the modified Rankin scale at 90 days showed a worse prognosis (median [IQR]; 5 [5–6] versus 3 [1–4]; P &lt;0.01). All perfusion imaging parameters were significantly predicting the sICH group in multiple logistic regression analysis. The value of relative cerebral blood volume was the parameter most strongly associated with sICH in receiver operating characteristic curve analysis (area under the curve=0.90, 95% CI [0.83–0.98]; cutoff 43 mL; sensitivity, 86 %; specificity, 87%). Conclusion Among perfusion computed tomography parameters, relative cerebral blood volume is highly associated with sICH after mechanical thrombectomy for cerebral large vessel occlusion. In patients with low relative cerebral blood volume regions, the indication of mechanical thrombectomy should be carefully considered for postoperative intracranial hemorrhage.

The claw sign predicts first-pass effect in mechanical thrombectomy for cerebral large vessel occlusion in the anterior circulation.

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE.Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE.Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047).Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke.

Circulating Cytokines and Growth Factors in Acute Cerebral Large Vessel Occlusion-Association with Success of Endovascular Treatment.

Mechanical thrombectomy (MT) is a highly efficient treatment in patients with acute ischemic stroke due to large vessel occlusion (LVO). However, in a relevant proportion of LVO, no sufficient recanalization can be achieved. The composition of cerebral thrombi is highly heterogeneous and may constitute a relevant factor for insufficient reperfusion. We hypothesized that circulating cytokines and growth factors involved in thromboinflammation and platelet activation may be associated with reperfusion status and thrombus composition in patients undergoing MT. An according biomarker panel was measured in plasma specimens taken prior to MT and at a 7-day follow-up. The reperfusion status was categorized into sufficient or insufficient. The composition of retrieved thrombi was histologically analyzed. Differences of baseline biomarker concentrations between insufficient and sufficient reperfusions were highest for interferon (IFN)-γ, epidermal growth factor, platelet-derived growth factor (PDGF)-AB/BB, and IFN-γ-induced protein 10 (IP-10/CXCL10). After applying correction for multiple comparisons and logistic regression analysis adjusting for stroke etiology, intravenous thrombolysis, and vascular risk factors, PDGF-AB/BB was identified as an independent predictor of reperfusion status (odds ratio: 0.403; 95% confidence interval: 0.199–0.819). Histological analysis revealed that the majority of thrombi had a mixed composition. In conclusion, this study provides the first evidence that cytokines and growth factors are potential effectors in patients undergoing MT for the treatment of acute ischemic stroke.

Time\u2013outcome relationship in acute large-vessel occlusion exists across all ages: subanalysis of RESCUE-Japan Registry 2

Early reperfusion after endovascular thrombectomy is associated with an improved outcome in ischemic stroke patients; however, the time dependency in elderly patients remains unclear. We investigated the time–outcome relationships in different age subgroups. Of 2420 patients enrolled in the RESCUE-Japan Registry 2 study, a study based on a prospective registry of stroke patients with acute cerebral large-vessel occlusion at 46 centers, we analyzed the data of 1010 patients with successful reperfusion after endovascular therapy (mTICI of 2b or 3). In 3 age subgroups (< 70, 70 to < 80, and ≥ 80 years), the mRS scores at 90 days were analyzed according to 4 categories of onset-to-reperfusion time (< 180, 180 to < 240, 240 to < 300, and ≥ 300 min). In each age subgroup, the distributions of mRS scores were better with shorter onset-to-reperfusion times. The adjusted common odds ratios for better outcomes per 1-category delay in onset-to-reperfusion time were 0.66 (95% CI 0.55–0.80) in ages < 70 years, 0.66 (95% CI 0.56–0.79) in ages 70 to < 80 years, and 0.83 (95% CI 0.70–0.98) in ages ≥ 80 years. Early reperfusion was associated with better outcomes across all age subgroups. Achieving early successful reperfusion is important even in elderly patients.

Acute Endovascular Revascularization for Patients with Common Carotid Artery Occlusion Apparent on Cervical Magnetic Resonance Angiography

ObjectivesIn the endovascular treatment of acute cerebral large-vessel occlusion, cervical magnetic resonance angiography (MRA) is a useful modality for assessing the access route. However, we sometimes encounter cases in which not only the internal carotid artery (ICA), but also the common carotid artery (CCA) is poorly visualized, leading to hesitation over which devices and techniques to choose for revascularization. We retrospectively evaluated such cases, focusing on image findings and treatment results. Materials and MethodsData from 96 patients who underwent acute endovascular revascularization from January 2016 to December 2019 were analyzed. We extracted patients with poor CCA visualization on cervical MRA from 35 cases with ICA occlusion, and examined angiographic findings, treatment methods, and outcomes. ResultsPoor visualization of the CCA in cervical MRA was observed in 8 cases. All cases displayed atrial fibrillation or sick sinus syndrome. Angiographic findings showed true CCA occlusion in 2 patients and ICA occlusion in 6 patients. Reasons for the inability to visualize the CCA on cervical MRA were speculated to be stenosis of the external carotid artery (ECA), presence of embolism in the ECA, or severe heart failure. In cases of true CCA occlusion, thrombus was aspirated using the balloon guide catheter and good recanalization was obtained. Seven of 8 patients displayed favorable recanalization, with good prognosis after 90 days in 5 patients. ConclusionsPoor CCA visualization on cervical MRA does not necessarily represent true CCA occlusion. Aspiration of thrombus from a balloon guide catheter is effective for true CCA occlusion.

Mechanical Thrombectomy for Acute Cerebral Large Vessel Occlusions Involving a Cerebral Aneurysm in the Target Vessel.

Mechanical thrombectomy (MT) for acute cerebral large vessel occlusion (LVO), which involves a cerebral aneurysm in the target vessel, indicates a risk of rupture of the aneurysm. Safety of the MT for LVO involving cerebral aneurysm was examined. In all, 240 consecutive patients with LVO were treated with MT between January 2018 and December 2019. Angiographic images and clinical records of patients with LVO involving cerebral aneurysm in the target vessel were retrospectively analyzed. Cerebral aneurysms were involved in seven patients (2.9%) in the target vessels. Aspiration thrombectomy was first considered; however, five of seven lesions were difficult to manage with aspiration thrombectomy alone. The stent retriever (SR) was combined with aspiration catheter for elongated vessel lesions and distal lesions. In all lesions, good recanalization was achieved without aneurysmal rupture. Aneurysms were identified in 2.9% of LVO in this study. Good recanalization was performed in all cases, and no cerebral aneurysmal rupture was observed during the perioperative period, and the procedure was relatively safe. Further case accumulation is needed for MT device selection and procedures for LVO involving cerebral aneurysm.

Incidence and Prognostic Impact of Intracranial Hemorrhage after Endovascular Treatment for Acute Large Vessel Occlusion

Introduction: Endovascular treatment (EVT) is effective against acute cerebral large vessel occlusion (LVO). However, it has been associated with a high incidence of intracranial hemorrhage (ICH). Because the incidence of ICH and prognostic impact of ICH were not scrutinized in general patients, we investigated the impact of ICH after EVT on functional outcome at 90 days in patients with acute LVO. Methods: RESCUE-Japan Registry 2 was a multicenter registry that enrolled 2,420 consecutive patients with acute LVO within 24 h of onset. We analyzed 1,281 patients who received EVT and compared the functional outcomes between those with and without ICH (ICH and no-ICH groups, respectively) within 24 h after EVT. We explored the factors associated with ICH and prognostic impact of symptomatic ICH (SICH) among patients with ICH. We estimated the adjusted odds ratios (ORs) for good functional outcome as modified Rankin Scale scores 0–2 and mortality. We also explored the prognostic impact of symptomatic ICH (SICH) among patients with ICH. Results: ICH occurred in 333 patients (26.0%). Several factors such as perioperative edaravone, stent retriever, and baseline glucose were associated with development of ICH within 24 h. A good outcome was observed in 80 (24.0%) and 454 (47.9%) patients in the ICH and no-ICH groups, respectively, and the adjusted OR was 0.3 (95% confidence interval [CI] = 0.2–0.5, p < 0.0001). Incidence of mortality within 90 days was not significantly different between the groups (adjusted OR 1.2; 95% CI: 0.7–1.9, p = 0.5). SICH was observed in 36 (10.8%) of 333 patients with ICH, and the good outcomes were 8.3 and 25.9% in patients with SICH and asymptomatic ICH (AICH), respectively (p = 0.02). Mortality at 90 days was 30.6 and 7.1% in patients with SICH and AICH, respectively (p < 0.0001). Conclusions: The functional outcomes at 90 days were significantly worse in patients who developed ICH after receiving EVT for acute LVO, but the mortality was generally similar.

Impact of introducing endovascular treatment on acute ischemic stroke outcomes: A shift from an era of medical management to thrombectomy in Japan

BackgroundEndovascular treatment (EVT) has increasingly become the standard treatment of acute cerebral large vessel occlusion (LVO). We evaluated the impact of introducing EVT on LVO therapy in a single center where intravenous thrombolysis (IVT) had been the only recanalization therapy. Materials and methodsBetween April 2013 and March 2017, 354 consecutive patients with LVO admitted to our institution were analyzed. We compared outcomes between two chronological groups before (Pre-EVT group) and after (Post-EVT group) introducing EVT in April 2015. We assessed prognostic factors for favorable outcomes (modified Rankin scale score ≤2 at 90 days). ResultsIn the Pre-EVT group, all 140 patients were treated medically, including 30 patients (21%) undergoing IVT. In the Post-EVT group, 118 patients (55%) underwent EVT, and the remaining 96 patients treated medically, including six patients (3%) undergoing IVT. The proportion undergoing recanalization therapy with IVT or EVT significantly increased after introducing EVT (21% versus 58%, p < 0.001). The rate of patients achieving favorable outcomes also significantly increased (14% versus 31%, p < 0.001). In multivariate regression analysis, introducing EVT was an independent predictive factor after adjusting for age, stroke severity and extent, and time (p = 0.005). The arrival time in patients with helicopter transport was significantly shorter than that with ground ambulance for a distance of more than 10 km (p < 0.001). ConclusionsThis study demonstrated that the introduction of EVT improved outcomes of acute LVO patients, increasing the opportunity to receive recanalization therapy. Further efforts to establish medical systems to provide EVT are required throughout the country.

Abstract TP260: Reducing Time From Pre-Hospital to Arterial Puncture in Acute Ischemic Stroke

Background and Purpose: Efficacy of mechanical thrombectomy for acute cerebral large vessel occlusion depends on time from symptom onset to reperfusion. While time to treatment in hospital has been optimized in these days, it is not well-known about improving time in pre-hospital when suspected stroke. We sought to analyze time from emergency medical services (EMS) dispatch to arterial puncture in stroke patients eligible for mechanical thrombectomy. Methods: We analyzed time components from EMS dispatch to puncture in patients with acute large vessel occlusion within 6 hours from onset treated with mechanical thrombectomy between April 2015 and December 2018. We assessed the associated factors with each time component and patient outcomes. Results: Consecutive 195 patients were included in this analysis. The median EMS dispatch-to-scene, on-scene, transport, door-to-puncture (DTP), and scene-to-puncture (STP) times were 4, 16, 12, 40, and 70 minutes, respectively. Percentage of favorable outcomes were significantly higher in patients with STP within 60 minutes (57.5% vs 35.8%, p&lt;0.05). Direct call from EMS, lower number of acceptance request times, shorter transport distance, and out-of-home onset were significantly associated with STP within 60 minutes (P&lt;0.01). EMS education program shortened STP times and increased use of direct call which significantly reduced on-scene (15.9 vs 20.2), DTP (40.4 vs 57.8), and STP (68.9 vs 91.5) times (P&lt;0.001). Conclusions: Reducing time in pre-hospital and in-hospital interact with each other. Education program and use of direct call from EMS contributed to reducing these times.

Abstract WP5: Effect of Complete Reperfusion on Outcome in Patients Undergoing Endovascular Therapy For Large Vessel Occlusion Stroke

Introduction: We investigated how the degree of reperfusion affects functional outcomes according to the puncture-to-reperfusion time and preoperative condition in patients with acute large vessel occlusion. Methods: A post-hoc analysis of the RESCUE-Japan Registry 2, a prospective multicenter registry enrolling patients with acute cerebral large vessel occlusion from 46 centers in Japan between October 1, 2014 and September 30, 2016, was conducted. Among the 2,420 patients in the RESCUE-Japan 2 registry, 1,073 patients who achieved successful reperfusion with endovascular therapy were analyzed. We compared the functional and safety outcomes between patients with modified thrombolysis in cerebral infarction grades 3 (mTICI-3) and 2b (mTICI-2b). Results: The proportion of patients with favorable outcomes (modified Rankin Scale scores of 0 to 2 at 90 days after onset) was higher among patients with mTICI-3 than among those with mTICI-2b (52% versus 38 %; adjusted OR, 1.96; 95% CI, 1.49-2.56). Compared to those in the patients with mTICI-2b within 30 minutes after puncture, favorable outcomes tended to be more common in patients who achieved mTICI-3 within 90 minutes after puncture (0-29 minutes: adjusted OR, 2.60; 95% CI, 1.24-5.46, 30-59 minutes adjusted OR, 1.65; 95% CI, 0.85-3.21, 60-89 minutes: adjusted OR, 1.61; 95% CI, 0.77-3.37; Figure). mTICI-3 reperfusion was associated with favorable outcomes in both anterior (adjusted OR, 1.81; 95% CI, 1.34-2.44) and posterior vessel occlusion (adjusted OR, 2.40; 95% CI, 1.06-5.44). There was no heterogeneity in the effect of mTICI-3 reperfusion on the outcomes with respect to age, NIHSS score, use of alteplase, late-presenting, distal vessel occlusion, or ASPECTS. Conclusions: mTICI-3 reperfusion, possibly even when reperfusion delays slightly, was superior to mTICI-2b. Achieving complete reperfusion, not only early reperfusion, is important to improve the outcomes regardless of preoperative condition.

Abstract TP54: Visual Aids for Patient, Family, and Physician Decision Making About Late Imaging-Guided Endovascular Thrombectomy for Acute Ischemic Stroke

Background: Speedy decision-making is helpful for optimal outcomes from endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). Visual displays may facilitate rapid review of relevant outcomes with different courses of action, but have not yet been developed for late-presenting patients selected for EVT based on multimodal CT or MR imaging. Methods: From pooled, study-level randomized trial (DAWN and DEFUSE 3) data, 100 person-icon arrays (Kuiper-Marshall personographs) were generated showing beneficial and adverse effects of endovascular thrombectomy for patients with acute cerebral ischemia and large vessel occlusion using (1) automated (algorithmic) and (2) expert-guided joint outcome table specification. Results: Among imaging-selected patients 6-24 hours from last known well, for the full 7-category modified Rankin Scale (mRS), endovascular thrombectomy had number needed to treat to benefit 1.9 (IQR 1.9-2.1) and number needed to harm 40.0 (29.2-58.3). Visual displays of treatment effects among 100 patients showed that, with EVT: 52 patients have better disability outcome, including 32 more achieving functional independence (mRS 0-2); 3 patients have worse disability outcome, including 1 more experiencing severe disability or death (mRS 5-6), mediated by symptomatic intracranial hemorrhage and infarct in new territory. The person-icon figure integrated these outcomes, and early side-effects, in a single display (Figure). Similar features were present in person-icon figures based on a 6-level mRS (levels 5 and 6 combined) rather than 7-level mRS, and giving special emphasis to normal or near-normal outcome (mRS 0-1) rather than functional independence (mR 0-2). Conclusion: Personograph visual decision aids are now available to rapidly educate patients, family, and healthcare providers on the benefits and risks of late, imaging-guided endovascular thrombectomy therapies for acute ischemic stroke.

Evaluation of the penumbra using DWI-FLAIR vascular hyperintensity mismatch in acute cerebral large–vessel occlusion

Evaluation of the penumbra using DWI-FLAIR vascular hyperintensity mismatch in acute cerebral large–vessel occlusion

Effects of sample storage time and temperature on prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen

Endovascular treatment (EVT) has increasingly become the standard treatment of acute cerebral large vessel occlusion (LVO). We evaluated the impact of introducing EVT on LVO therapy in a single center where intravenous thrombolysis (IVT) had been the only recanalization therapy.Between April 2013 and March 2017, 354 consecutive patients with LVO admitted to our institution were analyzed. We compared outcomes between two chronological groups before (Pre-EVT group) and after (Post-EVT group) introducing EVT in April 2015. We assessed prognostic factors for favorable outcomes (modified Rankin scale score ≤2 at 90 days).In the Pre-EVT group, all 140 patients were treated medically, including 30 patients (21%) undergoing IVT. In the Post-EVT group, 118 patients (55%) underwent EVT, and the remaining 96 patients treated medically, including six patients (3%) undergoing IVT. The proportion undergoing recanalization therapy with IVT or EVT significantly increased after introducing EVT (21% versus 58%, p < 0.001). The rate of patients achieving favorable outcomes also significantly increased (14% versus 31%, p < 0.001). In multivariate regression analysis, introducing EVT was an independent predictive factor after adjusting for age, stroke severity and extent, and time (p = 0.005). The arrival time in patients with helicopter transport was significantly shorter than that with ground ambulance for a distance of more than 10 km (p < 0.001).This study demonstrated that the introduction of EVT improved outcomes of acute LVO patients, increasing the opportunity to receive recanalization therapy. Further efforts to establish medical systems to provide EVT are required throughout the country.

The Claw Sign: An angiographic Predictor of Recanalization After Mechanical Thrombectomy for Cerebral Large Vessel Occlusion

Background: Mechanical thrombectomy undoubtedly improves functional outcomes for patients with acute ischemic stroke. Although we have observed occlusion sites that protrude proximally into the vessel on angiography, termed the “claw sign,” we have been unable to state its clinical significance. In this study, we aimed to determine whether the presence of a claw sign was related to recanalization success after mechanical thrombectomy. Materials and Methods: We retrospectively included 73 consecutive patients treated for acute cerebral large vessel occlusion by mechanical thrombectomy between January 2014 and December 2017. The angiographic claw sign was defined as a thrombus that protruded proximally by more than half the diameter of the parent artery. Claw sign positivity, clinical and etiological features, and outcomes were compared between groups with and without recanalization. Results: The claw sign was observed in 29 of 73 (40%) patients and was positive significantly more frequently in those with recanalization (50.0%) than in those without recanalization (5.9%) (P < .01). By multivariate analysis, the claw sign was the only pretreatment parameter to predict successful recanalization (odds ratio, 12.50; 95% confidence interval, 1.50-103.00; P = .019). Conclusions: The presence of the claw sign might predict successful recanalization in patients undergoing mechanical thrombectomy for large vessel occlusion.

Impact of Endovascular Therapy in Patients With Large Ischemic Core: Subanalysis of Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2

Endovascular therapy (EVT) is strongly recommended for acute cerebral large vessel occlusion with the Alberta Stroke Program Early CT Score (ASPECTS) ≥6 due to occlusion of the internal carotid artery or M1 segment of the middle cerebral artery. However, the effect of EVT for patients who have ischemic core with ASPECTS ≤5 (0–5) was not established. The purpose of this study was to elucidate the outcomes of EVT for patients with large ischemic core. Based on the data of The Recovery by Endovascular Salvage for Cerebral Ultra-Acute Embolism Japan Registry 2, patients with internal carotid artery or M1 segment of the middle cerebral artery occlusion and pretreatment ASPECTS 0 to 5 on noncontrast CT or diffusion-weighted image were extracted, and the outcomes by EVT were analyzed. Primary end point was defined as a good functional outcome (modified Rankin Scale score of ≤2) after 90 days. Among 2420 registered patients, 504 patients were with internal carotid artery or M1 segment of the middle cerebral artery occlusion and ASPECTS 0 to 5. Among these 504 patients, 172 (34.1 %) were treated with EVT (EVT group) and 332 (65.9 %) without (no-EVT group). In the no-EVT group, elderly patients, females, poor prestroke modified Rankin Scale, high National Institutes of Health Stroke Scale, low ASPECTS, and late admission were significantly more observed. Good functional outcomes were significantly more observed in the EVT group than in the no-EVT group (19.8 % versus 4.2 %; P<0.0001; adjusted odds ratio, 2.33; 95% CI, 1.10–4.94). The incidences of symptomatic intracranial hemorrhage within 72 hours did not significantly different between the EVT group and the no-EVT group (3.7 % versus 4.9%; P=0.55; adjusted odds ratio, 0.50; 95% CI, 0.14–1.73). Although outcomes in this group of patients were usually poor, the data suggested EVT may increase the likelihood of a good functional outcome.

Abstract TP1: Sex Differences in Management and Outcomes of Acute Ischemic Stroke With Large Vessel Occlusion: Sub-Analysis of RESCUE-Japan Registry 2

Background: Several studies have shown that women have a poorer prognosis after stroke than men. However, there were scanty data on sex difference in the management and clinical outcomes of acute ischemic stroke due to large vessel occlusion. Methods: Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism (RESCUE)-Japan Registry 2 in Japan registered patients with acute ischemic stroke due to large vessel occlusion who were admitted within 24 hours of onset from 2014 to 2017. We estimated the likelihood to receive endovascular therapy between the sexes. Primary outcome was good functional outcome defined by modified Rankin Scale (mRS) of 0-2 at 90 days after onset. Secondary outcome was the mortality within 90 days after onset. Adjusted odds ratio (OR) was estimated by logistic regression model accounted for potential confounders. Safety endpoints were all bleeding included intracerebral hemorrhage, recurrence of stroke within 90 days. Results: Among 2399 patients registered, 1087 patients were female and 1312 were male. Mean age was 80 and 73 years in female and male patients, respectively. Cardioembolic stroke consisted of 77% and 71% of female and male patients, respectively. 47.9% of female patients received the endovascular therapy compared with 57.7% in the counterparts (adjusted OR 0.69, 95%CI 0.58-0.83). Good outcome was observed in 27.3% and 44.2% the female and male patients, respectively (p&lt;0.0001). Adjusted OR of good outcome of female relative to male was 0.79 (95%CI: 0.64-0.98). Subgroup analyses showed the female was good prognosis over 75 years old [adjusted OR 0.57 (95%CI 0.43-0.77) while not differ under 75 years old [adjusted OR 1.24 (95%CI 0.89-1.72)] (interaction p=0.0001). The mortality was 12.3% and 9.9% in female and male patients (p = 0.06), and adjusted OR was not also statistically significant. Conclusions: Female patients with acute cerebral large vessel occlusion has poor prognosis compared to male. Female patients were less likely to receive endovascular therapy than male but such lower utilization of endovascular therapy accounted for a part of poor prognosis in female patients. The causes of poor prognosis in female patients should be attested in addition to the improved access to endovascular therapy in female.

Abstract WP46: Association of Onset-to-Reperfusion Time With 90-Day Outcome in Octogenarian: RESCUE-Japan Registry 2

Background and Purpose: Clinical outcomes after successful endovascular therapy in patients with acute ischemic stroke are associated with several factors including onset-to-reperfusion time (ORT). The objective of the current study was to assess whether ORT is associated with outcomes in elderly. Methods: Among 2420 patients enrolled in the RESCUE 2 study, a prospective stroke registry with acute cerebral large-vessel occlusion at 46 centers between October 2014 and January 2017, we enrolled 397 elderly patients more than 80 with successful reperfusion after thrombectomy (thrombolysis in cerebral infarction [TICI] score of 2b or 3) in the current analysis. The rates of good outcome (modified Rankin Scale [mRS] scores of 0-2 at 3 months) were compared among the three categories of ORT (&lt;180 minutes, 180-239 minutes, and ≥240 minutes). We developed multivariate logistic regression model to assess the independent association of the ORT with good outcome by adjusting for clinically relevant factors. Results: The rates of good outcome were 41% (30/73), 34% (26/77), and 25% (62/247) in each category of ORT. Odds ratio and 95% confidence interval for good outcome were 0.68 and 0.49-0.94 per 1 category delay. Conclusion: ORT was associated with good outcome even in elderly patients.

Abstract WP292: Differential Ability of Prehospital Large Vessel of Occlusion Scales to Identify Intracranial Hemorrhage

Background: Prehospital scales have been developed to identify patients with acute cerebral ischemia large vessel occlusion (ACI LVO) for direct routing to endovascular procedures. However intracranial hemorrhage patients can benefit significantly when directed to comprehensive stroke centers with neurosurgical services, but few prehospital scales have been validated for the detection of intracranial hemorrhage. Purpose: Differentiate the ability of prehospital large vessel of occlusion scales, such as LAMS, FAST-ED, RACE, and C-STATS to identify intracranial hemorrhage Methods: We analyzed early assessment and outcome data prospectively gathered in the FAST-MAG trial (Field Administration of Stroke Therapy-Magnesium phase 3) among patients with acute cerebrovascular disease (cerebral ischemia and intracranial hemorrhage) within 2 hours of onset, transported by 315 ambulances to 60 receiving hospitals. Results: Among 1700 patients (age 69±13 years, female 42.6%) 73.3% of patients had final diagnosis of cerebral ischemia, 22.8% diagnosis of intracranial hemorrhage, and 3.9% had stroke-mimicking conditions. Time from onset to prehospital LAMS was median 30 minutes (IQR 20-50), onset to hospital arrival LAMS was 145 minutes (IQR 119-180). All 4 scales performed moderately well in identifying ICH among patients with ACI: LAMS 0.75 C statistic; 0.63 accuracy; FAST-ED 0.72 C-statistic, 0.65 accuracy; RACE 0.70 C-statistic, 0.64 accuracy; C-STATS 0.71 C statistic, 0.67 accuracy. Conclusions: The prehospital LAMS and ED-performed C-STAT, RACE, and FAST-ED performed roughly equally at identifying Intracranial Hemorrhage patients with good accuracy.

Subacute Infarct Volume With Edema Correction in Computed Tomography Is Equivalent to Final Infarct Volume After Ischemic Stroke: Improving the Comparability of Infarct Imaging Endpoints in Clinical Trials.

Final infarct volume is regularly used as an end point of tissue outcome in stroke trials; however, the reported volumes are most commonly derived from early follow-up imaging. Those volumes are significantly impaired by ischemic edema, which causes an overestimation of the true final lesion volume. As net water uptake within ischemic brain can be quantified densitometrically in computed tomography (CT) as recently described, we hypothesized that the final lesion volume can be better estimated by correcting the lesion volume in early follow-up for the corresponding proportion of edema. After retrospective consecutive screening of the local registry, 20 patients with acute middle cerebral artery large vessel occlusion met the inclusion criteria with early and late follow-up CT; the latter acquired at least 4 weeks after admission. In early follow-up imaging 24 hours after onset, the proportion of edema contributing to the infarct lesion was calculated by quantifying the total volume of ischemic net water uptake. Edema volume was then subtracted from the total lesion volume to obtain edema-corrected lesion volumes. Finally, these corrected lesion volumes were compared with the final lesion volume on late follow-up serving as ground truth. The median lesion volume in the early follow-up was 115.1 mL (range, 21.9-539.9 mL) and significantly exceeded the median final lesion volume in the late follow-up CT, which was 86.6 mL (range, 11.2-399.0 mL; p < 0.001). The calculated mean proportion of edema within the early lesion volume was 25.8% (±5.9%; range, 11.1%-35.9%. The median edema-corrected lesion volume measured after 24 hours was 87.1 mL (range, 18.2-376.3 mL). The estimation of final lesion volume in the early follow-up CT was therefore improved by a mean of 31.4% (±2.1%) when correcting for the proportion of edema and did not differ significantly from the true final infarct volume (p = 0.2). Edema-corrected volumes of early follow-up infarct lesion in CT were in close agreement with the actual final infarct volumes. Computed tomography-based edema correction of subacute infarct lesions improves the estimation of final tissue outcome. This could especially improve the comparability of imaging end points and facilitate patient recruitment in clinical trials.