Anterior Large Vessel Occlusion Stroke Research Articles

Identification of Anterior Large Vessel Occlusion Stroke During the Emergency Call: Protocol for a Controlled, Nonrandomized Trial.

Endovascular thrombectomy (ET), combined with intravenous thrombolysis if possible, is an effective treatment option for patients with stroke who have confirmed anterior large vessel occlusion (aLVO). However, ET is mainly limited to comprehensive stroke centers (CSCs), resulting in a lack of ET capacity in remote, sparsely populated areas. Most stroke networks use the "Drip and Ship" or "Mothership" strategy, resulting in either delayed ET or intravenous thrombolysis, respectively. This study protocol introduces the Leitstellen-Basierte Erkennung von Schlaganfall-Patienten für eine Thrombektomie und daraufhin abgestimmte Optimierung der Rettungskette (LESTOR) strategy, developed to optimize the preclinical part of the stroke chain of survival to improve the clinical outcome of patients with suspected aLVO stroke. This involves refining the dispatch strategy for identifying patients with acute aLVO stroke using a phone-based aLVO query. This includes dispatching emergency physicians and emergency medical services (EMS) to urban emergency sites, as well as dispatching helicopter EMS to remote areas. If a highly suspected aLVO is identified after a standardized aLVO score evaluation during a structured examination at the emergency scene, prompt transport to a CSC should be prioritized. The LESTOR study is a controlled, nonrandomized study implementing the LESTOR strategy, with a stepped-wedge, cluster trial design in 6 districts in southwest Germany. In an interprofessional, iterative approach, an aLVO query or dispatch protocol intended for use by dispatchers, followed by a coordinated aLVO examination score for use by EMS, is being developed, evaluated, and pretested in a simulation study. After the training of all participating health care professionals with the corresponding final aLVO query, the LESTOR strategy is being implemented stepwise. Patients otherwise receive usual stroke care in both the control and intervention groups. The primary outcome is the modified Rankin Scale at 90 days in patients with stroke receiving endovascular treatment. We will use a generalized linear mixed model for data analysis. This study is accompanied by a cost-effectiveness analysis and a qualitative process evaluation. This paper describes and discusses the protocol for this controlled, nonrandomized LESTOR study. Enrollment was completed in June 2023. Data analysis is ongoing and the first results are expected to be submitted for publication in 2024. The project started in April 2020 and will end in February 2024. We expect that the intervention will improve the clinical outcome of patients with aLVO stroke, especially outside the catchment areas of CSCs. The results of the accompanying process evaluation and the cost-effectiveness analysis will provide further insights into the implementation process and allow for a better interpretation of the results. German Clinical Trials Register DRKS00022152; https://drks.de/search/de/trial/DRKS00022152. DERR1-10.2196/51683.

Prominent Vessel Signs After Endovascular Thrombectomy Corelates with Unexplained Neurological Deterioration and is a More Reliable Imaging Predictor of Prognosis in Anterior Large Vessel Occlusion Stroke

Fifty percent of patients who undergo endovascular thrombectomy (EVT) for large-vessel occlusion exhibit unfavorable outcomes. The primary factor is attributed to persistent brain impairment even after successful EVT. The prominent vessel sign (PVS) on magnetic resonance susceptibility-weighted imaging (SWI) reflects the territory of dysmetabolism and may facilitate an expeditious assessment for prognostication. We aimed to examine the relationship between PVS after EVT and the occurrence of early neurological deterioration (END) and 3-month outcomes. Patients who underwent EVT and multimodal MRI were included. END was defined as an increase of ≥ 2 in the NIHSS within 72h after EVT. Symptomatic intracranial hemorrhage, malignant edema, and surgical complications were defined as definite END, whereas the other symptoms were categorized as ux-END. The PVS-ASPECTS score was used to evaluate the asymmetric cerebral venous signal on the SWI sequences semi-quantitatively. A total of 116 eligible patients were included, 18 (15.5%) of whom presented with ux-END. The 72h NIHSS was strongly correlated with DWI infarct volume and PVS-ASPECTS and was significantly higher in the ux-END group (16±6 vs. 5±4, P=0.001). The PVS-ASPECTS score was significantly associated with poor outcomes (OR 2.551,95%CI 1.722-3.780, p＜0.001), and PVS-ASPECTS (AUC 0.884,95%CI 0.815-0.953, P < 0.001) was superior to DWI infarct volume (AUC 0.720,95%CI 0.620-0.820, P=0.001) in predicting 3-month poor outcome. At the optimal cut-off of 2, the PVS-ASPECT predicted poor outcomes with a sensitivity of 89.7% and a specificity of 78.2%. PVS 72h after EVT correlated with ux-END. The PVS-ASPECTS is a more reliable predictor of stroke prognosis and provides valuable information regarding post-EVT management.

Automated CT angiography collateral scoring in anterior large vessel occlusion stroke: A multireader study.

Computed tomography (CT) angiography collateral score (CTA-CS) is an important clinical outcome predictor following mechanical thrombectomy for ischemic stroke with large vessel occlusion (LVO). The present multireader study aimed to evaluate the performance of e-CTA software for automated assistance in CTA-CS scoring. Brain CTA images of 56 patients with anterior LVO were retrospectively processed. Twelve readers of various clinical training, including junior neuroradiologists, senior neuroradiologists, and neurologists graded collateral flow using visual CTA-CS scale in two sessions separated by a washout period. Reference standard was the consensus of three expert readers. Duration of reading time, inter-rater reliability, and statistical comparison of readers' performance metrics were analyzed between the e-CTA assisted and unassisted sessions. e-CTA assistance resulted in significant increase in mean accuracy (58.6% to 67.5%, p = 0.003), mean F1 score (0.574 to 0.676, p = 0.002), mean precision (58.8% to 68%, p = 0.007), and mean recall (58.7% to 69.9%, p = 0.002), especially with slight filling deficit (CTA-CS 2 and 3). Mean reading time was reduced across all readers (103.4 to 59.7 s, p = 0.001), and inter-rater agreement in CTA-CS assessment was increased (Krippendorff's alpha 0.366 to 0.676). Optimized occlusion laterality detection was also noted with mean accuracy (92.9% to 96.8%, p = 0.009). Automated assistance for CTA-CS using e-CTA software provided helpful decision support for readers in terms of improving scoring accuracy and reading efficiency for physicians with a range of experience and training backgrounds and leading to significant improvements in inter-rater agreement.

Good outcome associated with blood-brain barrier disruption and lower blood pressure after endovascular therapy

ObjectivesTo evaluate the association between post-endovascular thrombectomy (EVT) blood-brain barrier (BBB) disruption on MRI or CT and average systolic blood pressure (SBP) with favorable 90-day functional outcome. Observational studies have found elevated SBP associated with worse outcomes post-EVT, while recent randomized trials found no difference in targeted BP reduction. There may be a subgroup of patients who benefit from targeted BP reduction post-EVT. MethodsThis is a single-center study of 1) anterior large vessel occlusion stroke patients treated with EVT from 2015 to 2021, 2) achieved mTICI grade 2b or 3. Hyperintense acute reperfusion marker (HARM), hemorrhagic transformation (HT), and midline shift at 3 h post-EVT and 24 h imaging were assessed independently by multiple raters. Binary logistic regression models were used to determine the association of post-EVT SBP with outcomes. BBB disruption was defined as HT or HARM on 3h post-EVT imaging. ResultsOf 103 patients, those with SBP 100-129 versus SBP 130-160 found no significant difference in favorable 90-day outcome (64% vs. 46%, OR 2.11, 95% CI 0.78-5.76, p=0.143). However, among 71 patients with BBB disruption, a significant difference in favorable outcome of 64% in SBP 100-129 vs. 39% in SBP 130-160 group (OR 5.93, 95% CI 1.50-23.45, p=0.011) was found. There was no difference in symptomatic ICH, 90-day mortality, midline shift (≥5 mm), and hemicraniectomy, between BP or BBB groups. ConclusionsBBB disruption on 3h post-EVT imaging and lower SBP was associated with favorable outcome. This imaging finding may guide targeted BP therapy and suggests need for a randomized control trial.

Atrial fibrillation is associated with poor long-term outcome after mechanical thrombectomy for anterior large vessel occlusion stroke

ObjectivesAtrial fibrillation (AF) is one of the leading causes of acute ischemic stroke (AIS). The aim of our study was to determine the influence of AF on the long-term outcome of patients with AIS due to anterior circulation large vessel occlusion (LVO) treated with mechanical thrombectomy (MT). MethodsOur study included 127 consecutive patients with AIS due to anterior LVO who underwent MT between January 2018 and March 2020. Demographics, clinical, radiological and treatment characteristics were prospectively collected. Modified Rankin scale (mRS) score ≤2 was defined as a good functional outcome. ResultsAF was detected in 62 (48.8%) patients. Patients with AF were elder (73.1 ± 8.7 vs. 58.5 ± 14.2 years, p<0.01) and usually female (56.5% vs. 36.9%, p=0.03). They had a lower percentage of good functional outcome (31.6% vs. 62.3%, p<0.01) and a higher mortality rate (47.5% vs. 18.5%, p<0.01) after one year of follow-up. In the multivariate logistic regression the variables that showed significance with p <0.05 in previous univariate analyses were included. The presence of AF (aOR 0.29, 95% CI 0.11-0.78, p=0.01) and initial NIHSS score >15 (aOR 0.25, 95% CI 0.11-0.56, p<0.01) were independent negative predictors of good functional outcome after one year of follow-up. However, the presence of AF did not affect all-cause mortality within one year (p=0.18). ConclusionAF and initial NIHSS score >15 are independent negative predictors of good long-term functional outcome in patients with AIS due to anterior circulation LVO treated with MT.

Machine Learning–Based Identification of Target Groups for Thrombectomy in Acute Stroke

Whether endovascular thrombectomy (EVT) improves functional outcome in patients with large-vessel occlusion (LVO) stroke that do not comply with inclusion criteria of randomized controlled trials (RCTs) but that are considered for EVT in clinical practice is uncertain. We aimed to systematically identify patients with LVO stroke underrepresented in RCTs who might benefit from EVT. Following the premises that (i) patients without reperfusion after EVT represent a non-treated control group and (ii) the level of reperfusion affects outcome in patients with benefit from EVT but not in patients without treatment benefit, we systematically assessed the importance of reperfusion level on functional outcome prediction using machine learning in patients with LVO stroke treated with EVT in clinical practice (N = 5235, German-Stroke-Registry) and in patients treated with EVT or best medical management from RCTs (N = 1488, Virtual-International-Stroke-Trials-Archive). The importance of reperfusion level on outcome prediction in an RCT-like real-world cohort equaled the importance of EVT treatment allocation for outcome prediction in RCT data and was higher compared to an unselected real-world population. The importance of reperfusion level was magnified in patient groups underrepresented in RCTs, including patients with lower NIHSS scores (0–10), M2 occlusions, and lower ASPECTS (0–5 and 6–8). Reperfusion level was equally important in patients with vertebrobasilar as with anterior LVO stroke. The importance of reperfusion level for outcome prediction identifies patient target groups who likely benefit from EVT, including vertebrobasilar stroke patients and among patients underrepresented in RCT patients with low NIHSS scores, low ASPECTS, and M2 occlusions.

Ultra‐Early Functional Improvement After Stroke Thrombectomy – Predictors and Implications

Background Neurocritical care is routinely provided to patients post‐endovascular thrombectomy (EVT) for anterior large vessel occlusion strokes. We aim to study the relationship between immediate improvement in National Institutes of Health Stroke Scale (NIHSS) score on outcomes post‐EVT and potential implications for postprocedural care. Methods We performed a retrospective review of anterior circulation large vessel occlusion (internal carotid/proximal middle cerebral artery) patients undergoing EVT. Demographic, clinical, and imaging information was analyzed. Ultra‐early functional improvement (UEFI) was defined as NIHSS score &lt;6 within 30 minutes of successful recanalization. We analyzed the incidence and predictors of UEFI, and explored reasons for neurological decline post‐UEFI. Results Of the 343 anterior large vessel occlusion patients undergoing EVT, mean age was 71 ± 15 and 46% were male. Mean NIHSS was 17 ± 6 and Time Last Known Well (TLKW) to arrival was 9 ± 11 hours. UEFI was observed in 23% (79/343) of patients. Independent predictors of UEFI included lower pretreatment NIHSS, favorable Alberta Stroke Program Early CT Score (ASPECTS), and lower admission systolic blood pressure. Rates of 90‐day‐modified Rankin scale 0–2 were higher (71% versus 33%, P &lt;0.01) and the rate of mortality (8% versus 28%, P &lt;0.01) was lower in the UEFI group compared with the non‐UEFI group. Amongst patients with UEFI, 1.3% (1/79) experienced increase in NIHSS by ≥4 points within 24 hours of EVT. This patient received thrombolysis, achieved TICI‐2B recanalization, and follow‐up neuroimaging revealed a parenchymal hemorrhage and an infarct volume of 44 mL. None of the patients with UEFI required continuous antihypertensive infusions. Conclusions Approximately 1‐in‐4 of anterior large vessel occlusion stroke patients undergoing EVT have an NIHSS score of &lt;6 within 30 minutes of successful recanalization. Only 1% of them experience significant decline in neurological status within 24 hours of the procedure with the majority achieving functional independence at 90 days. The need for advanced neurocritical care should be reevaluated in these patients.

Stroke Core Volume Weighs More Than Recanalization Time for Predicting Outcome in Large Vessel Occlusion Recanalized Within 6 h of Symptoms Onset.

IntroductionCurrent guidelines suggest that perfusion imaging should only be performed > 6 h after symptom onset. Pathophysiologically, brain perfusion should matter whatever the elapsed time. We aimed to compare relative contribution of recanalization time and stroke core volume in predicting functional outcome in patients treated by endovascular thrombectomy within 6-h of stroke-onset.MethodsConsecutive patients presenting between January 2015 and June 2021 with (i) an acute ischaemic stroke due to an anterior proximal occlusion, (ii) a successful thrombectomy (TICI >2a) within 6-h of symptom-onset and (iii) CT perfusion imaging were included. Core stroke volume was automatically computed using RAPID software. Two linear regression models were built that included in the null hypothesis the pre-treatment NIHSS score and the hypoperfusion volume (Tmax > 6 s) as confounding variables and 24 h post-recanalization NIHSS and 90 days mRS as outcome variables. Time to recanalization was used as covariate in one model and stroke core volume as covariate in the other.ResultsFrom a total of 377 thrombectomies, 94 matched selection criteria. The Model null hypothesis explained 37% of the variability for 24 h post-recanalization NIHSS and 42% of the variability for 90 days MRS. The core volume as covariate increased outcome variability prediction to 57 and 56%, respectively. Time to recanalization as covariate marginally increased outcome variability prediction from 37 and 34% to 40 and 42.6%, respectively.ConclusionCore stroke volume better explains outcome variability in comparison to the time to recanalization in anterior large vessel occlusion stroke with successful thrombectomy done within 6 h of symptoms onset. Still, a large part of outcome variability prediction fails to be explained by the usual predictors.

Abstract WP165: Clinical And Radiological Characteristics Of Exponential And Non-exponential Infarct Growth Patterns In Anterior Circulation Large Vessel Occlusion Stroke

Introduction: Infarct evolution is a highly dynamic process that varies among individuals. This study aimed to identify clinical and radiological features associated with an exponential infarct growth rate (IGR) pattern in stroke patients with large vessel occlusion (LVO). Methods: This is a retrospective cohort study of anterior LVO stroke patients who underwent mechanical thrombectomy (MT) and achieved complete recanalization (mTICI 2c-3). Infarct volumes were calculated at two time points, pre-MT: CT perfusion (CTP) using Rapid software to estimate the CBF&lt;30% volume; and post-MT: using DWI-MRI. Early IGR was defined as CBF&lt;30% (ml) / Time from stroke onset to CTP (hours); and late IGR as [DWI-MRI - CBF&lt;30%] (ml) / Time from CTP to reperfusion (hours). Exponential IGR pattern was established when late IGR was at least three times its respective early IGR. Patients who did not meet this criterion were considered to have a non-exponential IGR. Hypoperfusion intensity ratio 0.4 identified patients with poor collateral status. Good functional outcome was defined as 90-day modified Rankin scale (mRS) 0-2. Results: Of the 159 patients (median age 71 [6-82], 45% male, median NIHSS 14 [9-18]) included in the analysis, 91 (57%) patients had an exponential IGR pattern. These patients had higher CT ASPECTS (9[7-10] vs 8[7-9], p=0.038), higher glucose levels (126[114-150] vs 117[106-135], p=0.022), lower Tmax&lt;6.0s (88[55-129] vs 113[81-173, p=0.014]), and higher rate of poor collaterals (31% vs 68%, p&lt;0.001) when compared to patients with a non-exponential IGR pattern. Patients with exponential IGR pattern had lower rates of mTICI 3 (82% vs 96%, p=0.008) but no significant differences in mRS 0-2 at 90 days. Conclusions: Parameters associated with exponential infarct growth might help to stratify the most time sensitive vulnerable LVO population in which newer therapeutic and triage strategies should be prioritized. Fig. Infarct Growth Rate Plots and Collateral Status . A shows IGR with an exponential pattern . B shows IGR with a non-exponential pattern.

Abstract P472: Characterization of Infarct Growth Rate Patterns in Patients With Large-Vessel Occlusion Stroke Undergoing Mechanical Thrombectomy

Introduction: Infarct growth is affected by the collateral blood supply and ischemic tolerance and thus unlikely linear. This study aimed to better characterize infarct growth rates (IGR) after large-vessel occlusion (LVO) stroke. Methods: We retrospectively identified patients with anterior LVO stroke who underwent mechanical thrombectomy (MT) at two comprehensive stroke centers. Core infarct volumes at presentation (CBF&lt;30%) were estimated using RAPID software. Final infarct volume (FIV) was measured on post-MT MRI. We estimated IGR during two intervals: IGR 1 defined as CBF&lt;30% (ml) / Time from onset to CTP (hours); and IGR 2 as [FIV - CBF&lt;30% (ml)] / Time from CTP to reperfusion (hours). To calculate IGR 2, we only analyzed patients with successful MT (mTICI ≥ 2b) assuming no significant infarct growth after reperfusion. Functional outcome was assessed using the modified Rankin scale (mRS) at 90 days. We performed the Receiver-operating characteristic (ROC) analysis for each interval to best classify patients into slow and fast progressors. Results: Of the 361 patients (age 68 ± 15, 55% female, NIHSS 14 ± 6) included in the analysis, 282 (78.1%) had successful reperfusion, and 150 (41.6%) achieved a good outcome (mRS ≤2). IGR showed an exponential growth pattern (Figure 1). There was no significant difference in the median IGR 1 between the poor and good outcome groups (2.3 vs. 1 ml, p=0.061). The median IGR 2 in patients with poor outcome was significantly higher when compared to those in the good outcome group (IGR 14.1ml/h vs. 4.62ml/h, p&lt;0.0001). IGR 2 ≥ 12.2ml/h had a sensitivity of 0.56 and a specificity of 0.77 (AUC 0.67) for predicting poor outcome. Conclusions: We identified an exponential infarct growth pattern after LVO stroke that differs in relation to outcome. High IGR in the interval from CTP to reperfusion is associated with worse outcomes, emphasizing the importance of future research into therapeutic approaches to slow down infarct progression.

Local Anesthesia Without Sedation During Thrombectomy for Anterior Circulation Stroke Is Associated With Worse Outcome.

The best anesthetic management for mechanical thrombectomy of large vessel occlusion strokes is still uncertain and could impact the quality of reperfusion and clinical outcome. We aimed to compare the efficacy and safety outcomes between local anesthesia (LA) and conscious sedation in a large cohort of acute ischemic stroke patients with anterior circulation large vessel occlusion strokes treated with mechanical thrombectomy in current, everyday clinical practice. Patients undergoing mechanical thrombectomy for anterior large vessel occlusion strokes at 4 comprehensive stroke centers in France between January 1, 2018, and December 31, 2018, were pooled from the ongoing prospective multicenter observational Endovascular Treatment in Ischemic Stroke Registry in France. Intention-to-treat and per-protocol analyses were used. Among the included 1034 patients, 762 were included in the conscious sedation group and 272 were included in the LA group. In the propensity score matched cohort, the rate of favorable outcome (90-day modified Rankin Scale score 0-2) was significantly lower in the LA group than in the conscious sedation group (40.0% versus 52.0%, matched relative risk=0.76 [95% CI, 0.60-0.97]), as well as the rate of successful reperfusion (modified Thrombolysis in Cerebral Infarction grade 2b-3; 76.6% versus 87.1%; matched relative risk=0.88 [95% CI, 0.79-0.98]). There was no difference in procedure time between the 2 groups. In the inverse probability of treatment weighting-propensity score-adjusted cohort, similar significant differences were found for favorable outcomes and successful reperfusion. In inverse probability of treatment weighting-propensity score-adjusted cohort, a higher rate of 90-day mortality and a lower parenchymal hematoma were observed after LA. The sensitivity analysis restricted to our per-protocol sample provided similar results in the matched- and inverse probability of treatment weighting-propensity cohorts. In the Endovascular Treatment in Ischemic Stroke registry mainly included patients in early time window (<6 hours), LA was associated with lower odds of favorable outcome, successful reperfusion, and higher odds of mortality compared with conscious sedation for mechanical thrombectomy of large vessel occlusion.

Abnormal Blood Flow on Transcranial Duplex Sonography Predicts Poor Outcome After Stroke Thrombectomy.

Background and Purpose- Hemodynamic changes following mechanical thrombectomy for large vessel occlusion stroke could be associated with complications and might affect prognosis. We investigated postinterventional middle cerebral artery blood flow on transcranial duplex sonography (TCD) and its prognostic value for anterior large vessel occlusion stroke patients. Methods- We identified all ischemic stroke patients who had undergone mechanical thrombectomy for anterior circulation large vessel occlusion from 2010 onwards. Postinterventional middle cerebral artery flow was graded according to the sonographic Thrombolysis in Brain Ischemia score and related to patient outcome stratified by the angiographic Thrombolysis in Cerebral Infarction reperfusion status. Results- Of 215 large vessel occlusion stroke patients, 193 patients (90%) showed successful angiographic recanalization (Thrombolysis in Cerebral Infarction grade 2b-3). Of those, 69 (36%) patients had abnormal sonographic middle cerebral artery blood flow (Thrombolysis in Brain Ischemia grade 0-4) within 72 hours after mechanical thrombectomy, which was an independent predictor for poor 90-day outcome. Conclusions- TCD indicates abnormal middle cerebral artery hemodynamics in a substantial proportion of patients with angiographically defined successful mechanical thrombectomy of the anterior cerebral circulation. Such changes are associated with poor short-term outcome.

Early Prediction of Poor Outcome Despite Successful Recanalization After Endovascular Treatment for Anterior Large Vessel Occlusion Stroke

Successful recanalization (SR) of the occluded artery does not always translate into a good outcome for patients with acute anterior circulation large-vessel occlusion stroke. This study aimed to develop a scale to predict poor outcome early despite SR after endovascular treatment (EVT) for candidates identified using current guidelines. The eligible patients with SR were retrospectively enrolled between 2014 and 2016. Poor outcome was defined as modified Rankin Scale of 3 to 6 at 90 days. Multivariable logistic regression was used to derive a PooR outcomE of enDovascular treatment wIth suCcessful recanalizaTion (PREDICT) scale. The discrimination and calibration of the scale were assessed. A total of 332 patients were enrolled. The PREDICT scale consisted of 5 items (prior intravenous thrombolysis, collateral status, blood glucose, blood neutrophil-to-lymphocyte ratio, and baseline National Institutes of Health Stroke Scale score). The scale had good discrimination and calibration. The risk of poor outcome was stratified into very low (PREDICT scale score ≤5), low (6-8), moderate (9-11), and high (≥12). Compared with patients with a score of ≤5, patients with a score of ≥12 had an 18.33-fold (95% confidence interval [CI], 6.36-52.89) increased risk of poor outcome. The PREDICT scale is a practical tool for early prediction of poor outcome despite SR after EVT in our patients and, if validated in other patient populations, may serve as a scale for identifying which patients are most, and least, likely to benefit from EVT.

Pittsburgh response to endovascular therapy score as a pre-treatment prognostic tool: External validation in Trevo2.

Background Optimal patient selection is needed to maximize the therapeutic benefit of endovascular therapy for large vessel occlusion stroke. Aims To validate the Pittsburgh response to endovascular therapy (PRE) score in a randomized controlled trial (Trevo2) comparing stent retriever (Trevo) to the Merci device. Methods Trevo2 participants with internal carotid, M1 and M2 middle cerebral artery occlusions with prospectively collected baseline stroke severity (NIHSS), degree of hypodensity (CT ASPECTS), and three-month modified Rankin Scale (mRS) were included. Multivariable regression was used to confirm association between PRE score variables (age, NIHSS, and ASPECTS), medical comorbidities, randomization arm, and reperfusion status (mTICI2B/3) with good outcome (three-month modified Rankin Scale 0-2). Predictive power (area under the receiver operating characteristic curve) for good outcome of pre-treatment prognostic scores (PRE, THRIVE, HIAT2) was compared. Rates of good outcome were compared between successfully reperfused (mTICI2B/3) and non-reperfused (mTICI0-2A) patients across previously identified PRE score risk groups. Results Age, NIHSS, ASPECTS, reperfusion status, and randomization arm were independent predictors of good outcome. PRE score had moderate predictive power (AUC = 0.75) for good outcome and was comparable to other pre-treatment scores. Reperfusion resulted in maximal treatment benefit in patients with PRE score 0-24 (60% vs. 12.5%, p = 0.002) but not in those with PRE ≥50 (11.8% vs. 0.0%, p = 0.49). Conclusion The PRE score is a validated predictor of functional outcome and a tool for patient selection for endovascular therapy in anterior large vessel occlusion stroke. Our finding of limited benefit of reperfusion in patients with PRE score ≥50 needs to be prospectively validated.

Relationship Between Lesion Topology and Clinical Outcome in Anterior Circulation Large Vessel Occlusions.

Diffusion-weighted imaging (DWI) Alberta Stroke Program Early CT Score (ASPECTS), a surrogate of infarct volume, predicts outcome in anterior large vessel occlusion strokes. We aim to determine whether topological information captured by DWI ASPECTS contributes additional prognostic value. Adults with intracranial internal carotid artery, M1 or M2 middle carotid artery occlusions who underwent endovascular therapy were included. The primary outcome measure was poor clinical outcome (3-month modified Rankin Scale score, 3-6). Prognostic value of the 10 DWI ASPECTS regions in predicting poor outcome was determined by multivariable logistic regression, controlling for final infarct volume, age, and laterality. Two hundred and thirteen patients (mean age, 66.1±14.5 years; median National Institutes of Health Stroke Scale, 15) were included. Inter-rater reliability was good for DWI ASPECTS (deep regions, κ=0.72; cortical regions, κ=0.63). All DWI ASPECTS regions with the exception of the putamen were significant predictors (P<0.05) of poor outcome in univariate analyses. Statistical collinearity among ASPECTS regions was not observed. Using penalized multivariable logistic regression, only M4 (odds ratio, 2.82; 95% confidence interval, 1.39-5.76) and M6 (odds ratio, 2.45; 95% confidence interval, 1.15-5.3) involvement were associated with poor outcome. M6 involvement independently predicted poor outcome in right hemispheric strokes (odds ratio, 5.8; 95% confidence interval, 1.9-20.3), whereas M4 (odds ratio, 4.3; 95% confidence interval, 1.3-15.0) involvement predicted poor outcome in left hemispheric strokes adjusting for infarct volume. Topologic information modestly improved the predictive ability of a prognostic score that incorporates age, infarct volume, and hemorrhagic transformation. Involvement of the right parieto-occipital (M6) and left superior frontal (M4) regions affect clinical outcome in anterior large vessel occlusions over and above the effect of infarct volume and should be considered during prognostication.