Early Computed Tomography Research Articles

A cortically-weighted versus total Alberta Stroke Program Early Computed Tomography Score in thrombectomy outcome models

ObjectivesIndividual subcortical infarct scoring for the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) can be difficult and is subjected to higher inter-reader variability. This study compares performance of the 10-point ASPECTS with a new 7-point cortically-weighted score in predicting post-thrombectomy functional outcomes. Materials and methodsProspective registry data from two comprehensive stroke centers (Site 1 2016-2021; Site 2: 2019-2021) included patients with either M1 segment of middle cerebral artery or internal carotid artery occlusions who underwent thrombectomy. Two multivariate proportional odds training models utilizing either 10-point or 7-point ASPECTS predicting 90-day shift in modified Rankin score were generated using Site 1 data and validated with Site 2 data. Models were compared using multiclass receiver operator characteristics, corrected Akaike's Information Criterion, and likelihood ratio test. ResultsOf 328 patients (Site 1 = 181, Site 2 = 147), median age was 71y (IQR 61-82), 119 (36%) had internal carotid artery occlusions, and median 10-point ASPECTS was 9 (IQR 8-10). There was no difference in performance between models using either total or cortically-weighted ASPECTS (p=0.14). Validation cohort data were correctly (i.e., predicting modified Rankin score within one point) classified 50% (cortically-weighted score model) and 56% (total score model) of the time. ConclusionsThe 7-point cortically-weighted ASPECTS was similarly predictive of post-thrombectomy functional outcome as 10-point ASPECTS. Given noninferior performance, the cortically-weighted score is a potentially reliable, but simplified, alternative to the traditional scoring paradigm, with potential implications in automated image analysis tool development.

Development and validation of a prognostic computed tomography scoring model for functional outcomes in patients with large hemispheric infarction following decompressive craniectomy.

There is no established prognostic scoring system developed for patients with large hemispheric infarction (LHI) following decompressive craniectomy (DC) based on imaging characteristics. The present study aimed to develop and validate a new computed tomography scoring model to assess the 6-month risk of poor functional outcomes (modified-Rankin scale [mRS] score of 4-6) in patients with LHI receiving DC. This retrospective cohort study included patients at two tertiary stroke centers. A prediction model was developed based on a multivariable logistic regression. The final risk factors included the ASPECTS (Alberta Stroke Program Early Computed Tomography Score), longitudinal fissure cistern, Sylvian fissure cistern, and additional vascular territory involvement. 1,000 bootstrap resamples and temporal validation were implemented as validations for the scoring system. Of the 100 individuals included in the development cohort, 71 had poor functional outcomes. The scoring model presented excellent discrimination and calibration with C-index = 0.87 for the development cohort, and C-index = 0.83 for the temporal validation cohort with non-significant Hosmer-Lemeshow goodness-of-fit test. The scoring model also showed an improved AUC compared to the ASPECTS. For each point in the score model, the adjusted risk of poor functional outcomes increase by 47.8% (OR = 1.48, p < 0.001). The scores were inversely correlated with MAP (mean arterial pressure, paired t-test, p = 0.0015) and CPP (cerebral perfusion pressure, rho = -0.17, p = 0.04). In patients with LHI following DC, the score system is an excellent predictor of poor functional outcomes and is associated with CPP and MAP, which might be worth considering in clinical settings after further external validation.

Prognostic value of CBV index in patients with acute ischemic stroke treated with endovascular thrombectomy in late therapeutic window.

To evaluate the prognostic value of the cerebral blood volume (CBV) index for 90-day functional outcomes in patients with acute ischemic stroke (AIS) treated within a late therapeutic window. We retrospectively reviewed patients who underwent pre-treatment computed tomography perfusion (CTP) and endovascular thrombectomy (EVT) for large-vessel occlusion (LVO) of the anterior circulation within the late therapeutic window between January 2021 and February 2023. Clinical data, the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) based on unenhanced computed tomography (CT), and perfusion parameters, including ischemic core, hypoperfusion volume, mismatch volume between the core and penumbra, and CBV index, were assessed and compared between patients who achieved favorable outcomes (defined as a modified Rankin Scale score of 0-2). Of the 118 patients, 56 (47.5%) had favorable outcomes. In the univariate analysis, age, National Institutes of Health Stroke Scale (NIHSS) score at admission, ASPECTS score, CBV index, and ischemic core volume were significantly associated with functional outcomes (P < 0.05). In multivariate analyses, age (odds ratio [OR], 1.060; 95% confidence interval [CI] 1.013-1.110, P = 0.012), NIHSS score at admission (OR, 1.126; 95% CI 1.031-1.229, P = 0.009), and CBV index (OR, 0.001; 95% CI 0.000-0.240, P = 0.014) were independent predictors of a 90-day favorable outcome. A high CBV index was independently associated with favorable outcomes in patients who underwent mechanical thrombectomy within the late therapeutic window. In addition, a higher CBV index reflects improved blood flow and favorable digital subtraction angiography collateral status.

Region-specific interobserver agreement of the Alberta Stroke Program Early Computed Tomography Score: A meta-analysis.

The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used scoring system for evaluating ischemic stroke to determine therapeutic strategy. However, there is variation in the interobserver agreement of ASPECTS. This systematic review and meta-analysis aimed to investigate the interobserver agreement of total and regional ASPECTS. A comprehensive search was conducted in the Web of Sciences, PubMed, and Scopus databases to identify relevant studies. Inclusion criteria were studies of noncontrast CT performed within 24hours of ischemic stroke in the middle cerebral artery territory. A total of 20 studies, with 3482 patients, reporting interobserver agreement of total and regional ASPECTS were included in the meta-analysis. The interobserver agreement for total ASPECTS in studies using Kappa coefficient (κ) analysis was substantial (κ=.67, 95% confidence interval [CI]: .57-.78). In studies using intraclass correlation coefficient (ICC) analysis, agreement was excellent (ICC=.84, 95% CI: .77-.90). Interobserver agreement was higher in studies in which the observer was unblinded to clinical scenario in both groups (κ=.74, 95% CI: .59-.89, and ICC=.82, 95% CI: .79-.85). Per-region analysis showed that the caudate nucleus had the highest agreement (κ=.68, 95% CI: .60-.76, and ICC=.84, 95% CI: .74-.93), while M2 and internal capsule in Kappa studies (κ=.45, 95% CI: .34-.55 and κ=.47, 95% CI: .28-.66), and M4 and internal capsule in ICC studies (ICC=.54, 95% CI: .43-.64 and ICC=.55, 95% CI: .18-.91) had the lowest agreement. This meta-analysis demonstrates substantial to excellent interobserver agreement for total ASPECTS, which supports using this method for stroke treatment. However, findings emphasize the need to consider interobserver agreement in specific regions of ASPECTS for treatment decisions.

Association Between Hypoperfusion Intensity Ratio and Postthrombectomy Malignant Brain Edema for Acute Ischemic Stroke.

Malignant brain edema (MBE) is a life-threatening complication that can occur after mechanical thrombectomy (MT) for acute ischemic stroke. The hypoperfusion intensity ratio (HIR) reflects the tissue-level perfusion status within the ischemic territory. This study investigated the association between HIR and MBE occurrence after MT in patients with anterior circulation large artery occlusion. We conducted a retrospective cohort study of patients who received MT at a comprehensive stroke center from February 2020 to June 2022. Using computed tomography perfusion, the HIR was derived from the ratio of tissue volume with a time to maximum (Tmax) > 10s to that with a Tmax > 6s. We dichotomized patients based on the occurrence of MBE following MT. The primary outcome, assessed using a multivariable logistic regression model, was the MBE occurrence post MT. The secondary outcome focused on favorable outcomes, defined as achieving a modified Rankin Scale score of 0-2 at 90days. Of the 603 included patients, 90 (14.9%) developed MBE after MT. The median HIR exhibited a significantly higher value in the MBE group compared with the non-MBE group (0.5 vs. 0.3; P < 0.001). Multivariable logistic regression analysis indicated that a higher HIR (adjusted odds ratio [aOR] 8.98; 95% confidence interval [CI] 2.85-28.25; P < 0.001), baseline large infarction (Alberta Stroke Program Early Computed Tomography Score < 6; aOR 1.77; 95% CI 1.04-3.01; P = 0.035), internal carotid artery occlusion (aOR 1.80; 95% CI 1.07-3.01; P = 0.028), and unsuccessful recanalization (aOR 8.45; 95% CI 4.75-15.03; P < 0.001) were independently associated with MBE post MT. Among those with successful recanalization, a higher HIR (P = 0.017) and baseline large infarction (P = 0.032) remained as predictors of MBE occurrence. Furthermore, a higher HIR (P = 0.001) and the occurrence of MBE (P < 0.001) both correlated with reduced odds of achieving favorable outcomes. The presence of a higher HIR on pretreatment perfusion imaging serves as a robust predictor for MBE occurrence after MT, irrespective of successful recanalization.

Association between infarct location and haemorrhagic transformation of acute ischaemic stroke after intravenous thrombolysis

To evaluate the association between computed tomography (CT)-based imaging variables at the time of admission and haemorrhagic transformation (HT) after intravenous thrombolysis (IVT). One hundred and eight patients who were treated with IVT for acute ischaemic stroke (AIS) during January 2021 to July 2023 were analysed retrospectively. The infarct location was classified as cortical or subcortical in accordance with the Alberta Stroke Program Early CT Score (ASPECTS) system. Logistic regression and receiver operating characteristic curve analyses were performed to determine the relationship between ischaemic variables and HT. Of the total, 18 (16.7%) patients had HT and seven (6.5%) had symptomatic intracerebral haemorrhage (sICH). Multivariate analysis revealed that cortical ASPECTS was independently associated with HT (odds ratio [OR], 0.197; 95% confidence interval [CI], 0.076-0.511; p=0.001) and cortical ASPECTS was independently associated with sICH (OR, 0.066; 95% CI, 0.009-0.510; p=0.009). To predict HT and sICH, cortical ASPECTS (HT area under the curve [AUC]=0.881, sICH AUC=0.971) provided a higher AUC compared with ASPECTS (HT AUC=0.850, sICH AUC=0.918). Cortical ASPECTS seen on CT at the time of admission is associated with HT and sICH after IVT.

The Role of Abdominal CT in the Management of Acute Abdominal Conditions in Children

Objectives: This study aimed to assess the influence of abdominal computerized tomography (CT) scans on the management of children presenting with acute abdominal conditions, considering concerns regarding radiation exposure. Methods: A retrospective review was conducted of all acute pediatric patients who underwent abdominal CT in a tertiary hospital, during 2018-2019. Results: Over the 2-year period, 976 pediatric patients were admitted due to acute abdominal conditions. Of 197 (20.2%) patients who underwent abdominal CT scans, management plan was modified based on CT results in 67.5%. In non-trauma cases, the impact on the management plan was even more pronounced, affecting 91.2% of patients, and led to invasive procedures (one third), non-invasive actions (one third), or discharge (one third). Multivariate analysis demonstrated a significantly higher odds ratios (OR) for impact on management in non-trauma patients (OR=24) as compared to trauma patients, especially younger (OR=1.58 annually) and male (OR=10.42) patients, and when performed early (OR=2.44, for each day earlier). Trauma patients with a lower body mass index (BMI) (OR=1.02 per percentile decrease) demonstrated a significantly larger impact. Conclusion: These results support a more liberal use of early CT scans in non-traumatic acute pediatric abdominal conditions, especially in younger male patients, with more careful consideration in trauma patients, particularly those with high BMIs.

Alberta Stroke Program Early Computed Tomography Score, Infarct Core Volume, and Endovascular Therapy Outcomes in Patients With Large Infarct

Endovascular therapy (EVT) demonstrated better outcomes compared with medical management in recent randomized clinical trials (RCTs) of patients with large infarct. To compare outcomes of EVT vs medical management across different strata of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and infarct core volume in patients with large infarct. This prespecified secondary analysis of subgroups of the Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients With a Large Infarct Core (ANGEL-ASPECT) RCT included patients from 46 stroke centers across China between October 2, 2020, and May 18, 2022. Participants were enrolled within 24 hours of symptom onset and had ASPECTS of 3 to 5 or 0 to 2 and infarct core volume of 70 to 100 mL. Patients were divided into 3 groups: ASPECTS of 3 to 5 with infarct core volume less than 70 mL, ASPECTS of 3 to 5 with infarct core volume of 70 mL or greater, and ASPECTS of 0 to 2. Endovascular therapy or medical management. The primary outcome was the ordinal 90-day modified Rankin Scale (mRS) score. There were 455 patients in the trial; median age was 68 years (IQR, 60-73 years), and 279 (61.3%) were male. The treatment effect did not vary significantly across the 3 baseline imaging subgroups (P = .95 for interaction). The generalized odds ratio for the shift in the 90-day mRS distribution toward better outcomes with EVT vs medical management was 1.40 (95% CI, 1.06-1.85; P = .01) in patients with ASPECTS of 3 to 5 and infarct core volume less than 70 mL, 1.22 (95% CI, 0.81-1.83; P = .23) in patients with ASPECTS of 3 to 5 and infarct core volume of 70 mL or greater, and 1.59 (95% CI, 0.89-2.86; P = .09) in patients with ASPECTS of 0 to 2. In this study, no significant interaction was found between baseline imaging status and the benefit of EVT compared with medical management in patients with large infarct core volume. However, estimates within subgroups were underpowered. A pooled analysis of large core trials stratified by ASPECTS and infarct core volume strata is warranted. ClinicalTrials.gov Identifier: NCT04551664.

Recanalization status and temporal evolution of early ischemic changes following stroke thrombectomy.

Present-day computer tomography (CT) scanners have excellent spatial resolution and signal-to-noise ratio and are instrumental detecting early ischemic changes (EIC) in brain. We assessed the temporal changes of EIC based on the recanalization status after thrombectomy. The cohort comprises consecutive patients with acute ischemic stroke in anterior circulation treated with thrombectomy in tertiary referral hospital. All baseline and follow-up scans were screened for any ischemic changes and further classified using Alberta Stroke Program Early CT Score (ASPECTS). Generalized linear mixed models were used to analyze the impact of recanalization status using modified Thrombolysis in Cerebral Infarction (mTICI) on temporal evolution of ischemic changes. We included 614 patients with ICA, M1, or M2 occlusions. Median ASPECTS score was 9 (IQR 7-10) at baseline and 7 (5-8) at approximately 24 h. mTICI 3 was achieved in 207 (33.8%), 2B 241 (39.3%), 2A in 77 (12.6%), and 0-1 in 88 (14.3%) patients. Compared to patients with mTICI 3, those with mTICI 0-1 and 2A had less favorable temporal changes of ASPECTS (p < 0.001). Effect of recanalization was noted in the cortical regions of ICA/M1 patients, but not in their deep structures or patients with M2 occlusions. All ischemic changes detected at baseline were also present at all follow-up images, regardless of the recanalization status. Temporal evolution of the ischemic changes and ASPECTS are related to the success of the recanalization therapy in cortical regions of ICA/M1 patients, but not in their deep brain structures or M2 patients. In none of the patients did EIC revert in any brain region after successful recanalization.

Simple approach to quantify hypoxic-ischemic brain injury severity from computed tomography imaging files after cardiac arrest

BackgroundGrey-white ratio (GWR) can estimate severity of cytotoxic cerebral edema secondary to hypoxic-ischemic brain injury after cardiac arrest and predict progression to death by neurologic criteria (DNC). Current approaches to calculating GWR are not standardized and have variable interrater reliability. We tested if measures of variance of brain density on early computed tomographic (CT) imaging after cardiac arrest could predict DNC. MethodsWe performed a retrospective cohort study, identifying post-arrest patients treated between 2011 and 2020 at our single center. We extracted demographic data from our registry and Digital Imaging and Communication in Medicine (DICOM) files for each patient’s first brain CT. We analyzed slices 15–20 of each DICOM, corresponding to the level of the basal ganglia while accommodating differences in patient anatomy. We extracted pixel arrays and converted the radiodensities to Hounsfield units (HU). To focus on brain tissue densities, we excluded HU > 60 and < 10. We calculated the variance of each patient’s HU distribution and the difference between the means of a two-group Gaussian finite mixture model. We compared these novel metrics to existing measures of cerebral edema, then randomly divided our data into 80% training and 20% test sets and used logistic regression to predict DNC. ResultsOf 1,133 included subjects, 457 (40%) were female, mean (standard deviation) age was 58 (16) years, and 115 (10%) progressed to DNC. CTs were obtained a median [interquartile range] of 4.2 [2.8–5.7] hours post-arrest. Our novel measures correlated weakly with GWR. HU variance, but not difference between mixture model means, differed significantly between subjects with and without sulcal or cistern effacement. GWR outperformed our novel measures in predicting progression to DNC with an area under the receiver operating characteristic curve (AUC) of 0.82, compared to HU variance (AUC = 0.73) and the difference between mixture model means (AUC = 0.56). ConclusionThere are differences in the distribution of HU on post-arrest CT in patients with qualitative measures of cerebral edema. Current methods to quantify cerebral edema outperform simple measures of attenuation variance on early brain CT. Further analyses could investigate if these measures of variance, or other distributional characteristics of brain density, have improved predictive performance on brain CTs obtained later in the clinical course or derived from discrete regions of anatomical interest.

Dynamic and visual nomograms to online predict unfavorable outcome of mechanical thrombectomy for acute basilar artery occlusion.

The evidence of mechanical thrombectomy (MT) in basilar artery occlusion (BAO) was limited. This study aimed to develop dynamic and visual nomogram models to predict the unfavorable outcome of MT in BAO online. BAO patients treated with MT were screened. Preoperative and postoperative nomogram models were developed based on clinical parameters and imaging features. An independent dataset was collected to perform external validation. Web-based calculators were constructed to provide convenient access. A total of 127 patients were included in the study, and 117 of them were eventually included in the analysis. The nomogram models showed robust discrimination, with an area under the receiver operating characteristic (ROC) of 0.841 (preoperative) and 0.916 (postoperative). The calibration curves showed good agreement. The preoperative predictors of an unfavorable outcome were previous stroke, the National Institutes of Health Stroke Scale (NIHSS) at admission, and the posterior circulation Alberta Stroke Program Early Computed Tomography Score (pc-ASPECTS). The postoperative predictors were previous stroke, NIHSS at 24h, and pc-ASPECTS. Dynamic and visual nomograms were constructed and validated for the first time for BAO patients treated with MT, which provided precise predictions for the risk of an unfavorable outcome. The preoperative model may assist clinicians in selecting eligible patients, and the postoperative model may facilitate individualized poststroke management.

Abstract 14130: Efficacy and Safety of Endovascular Therapy in Stroke Patients With Large Ischemic Core in Comparison to Medical Management: Meta-Analysis of Randomized Control Studies

Introduction: Endovascular therapy (EVT) is a treatment recommended for stroke patients with large vessel occlusion and an Alberta Stroke Program Early Computed Tomography Score (ASPECTS) ≥6. However, the utility of EVT in patients with large core ischemic stroke has not been well established. Methods: This meta-analysis assesses EVT's efficacy and safety using available trials comparing EVT to medical management (MM) in stroke patients with large ischemic core. Eligibility criteria: 1) were randomized controlled trials, 2) compared EVT with MM alone, 3) studied patients presenting with LIC cerebrovascular events, and 4) reported outcomes of interest. We extracted data for the major imaging inclusion criteria, the National Institutes of Health Stroke Scale (NIHSS) score, pre-stroke mRs score, and occlusion site. We also extracted outcome data for the EVT groups vs MM groups, including measurement of early neurological recovery, and definition of sICH. Results: Our primary end point was the mean modified Rankin scale score (RSS) at 90-day follow up. EVT was associated with higher odds of significant improvement in functional status with reduction in mean mRS by -0.31 [-0.47; -0.14]) compared to MM. The odds of achieving mRS 0 to 2 was higher in the EVT arm compared to the MM arm (2.53 [1.59; 4.02]). There was no difference in achieving mRS 0 to 3, early neurologic improvement defined according to NIHSS score, overall 90-day mortality and risk of symptomatic ICH between patients treated with EVT or MM in our analysis. Conclusions: Our study suggests that EVT may lead to improved outcomes in stroke patients with large core ischemia.

Abstract 256: Proposal of multimodal CT‐based scoring system in prediction of hemorrhagic transformation in acute ischemic stroke

Introduction The routinely used computed tomography (CT)‐based workup in the setting of acute ischemic stroke (AIS) includes non‐contrast brain CT, CT angiography (CTA), and CT perfusion. Several CT, CTA, CTP‐based radiological biomarkers of hemorrhagic transformation (HT) were reported. To assess the predictive value of the combined multimodal CT parameters for HT after AIS and proposal of predictive scoring scale. Methods The source images of the NCCT, CTA and CTP of 282 AIS patients involving the anterior circulation (HT = 91, non‐HT = 191) were retrospectively reviewed and the following biomarkers were recorded and analyzed: Early subtle ischemic signs, hyperdense middle cerebral artery sign (HMCAS) and Alberta Stroke Program Early CT Score (ASPECTS) &lt; 7 in NCCT, large‐vessel occlusion (LVO), clot burden score (CBS) &lt; 6, large‐vessel occlusion, poor collateral score (CS) and Tmax &gt; 6 s ≥ 56.5 ml. A scoring system to predict HT based on these biomarkers was developed. Each biomarker counts for a single point with the total score ranging from 0 to 7. Results All the aforementioned multimodal CT biomarkers and the selected cut offs were significantly associated with higher HT risk. The calculated scores were statistically significant different between the HT and the non‐HT groups with AUC 0.761 (95% CI 0.703–0.819, P &lt; 0.0000001). Rates of HT were approximately five times higher in patients with score ≥ 3. Conclusion Multimodal CT‐based scoring system may provide highly reliable predictive model of hemorrhagic transformation in acute ischemic stroke.

Aspiration Versus Stent‐Retriever as First‐Line Endovascular Therapy Technique for Primary Medium and Distal Intracranial Occlusions: A Propensity‐Score Matched Multicenter Analysis

Background For acute proximal intracranial artery occlusions, contact aspiration may be more effective than stent‐retriever for first‐line reperfusion therapy. Due to the lack of data regarding medium vessel occlusion thrombectomy, we evaluated outcomes according to first‐line technique in a large, multicenter registry. Methods Imaging, procedural, and clinical outcomes of patients with acute proximal medium vessel occlusions (M2, A1, or P1) or distal medium vessel occlusions (M3, A2, P2, or further) treated at 37 sites in 10 countries were analyzed according to first‐line endovascular technique (stent‐retriever versus aspiration). Multivariable logistic regression and propensity‐score matching were used to estimate the odds of the primary outcome, expanded Thrombolysis in Cerebral Infarction score of 2b–3 (“successful recanalization”), as well as secondary outcomes (first‐pass effect, expanded Thrombolysis in Cerebral Infarction 2c‐3, intracerebral hemorrhage, and 90‐day modified Rankin scale, 90‐day mortality) between treatment groups. Results Of the 440 included patients (44.5% stent‐retriever versus 55.5% aspiration), those treated with stent‐retriever had lower baseline Alberta Stroke Program Early Computed Tomography Scale scores (median 8 versus 9; P &lt;0.01), higher National Institutes of Health Stroke Scale scores (median 13 versus 11; P =0.02), and nonsignificantly fewer medium‐distal occlusions (M3, A2, P2, or other: 17.4% versus 23.8%; P =0.10). Use of a stent‐retriever was associated with 15% lower odds of successful recanalization (odds ratio [OR], 0.85; [95% CI 0.74–0.98]; P =0.02), but this was not significant after multivariable adjustment in the total cohort (adjusted OR, 0.88; [95% CI 0.72–1.09]; P =0.24), or in the propensity‐score matched cohort (n=105 in each group) (adjusted OR, 0.94; [95% CI 0.75–1.18]; P =0.60). There was no significant association between technique and secondary outcomes in the propensity‐score matched adjusted models. Conclusion In this large, diverse, multinational medium vessel occlusion cohort, we found no significant difference in imaging or clinical outcomes with aspiration versus stent‐retriever thrombectomy.

Endovascular thrombectomy for acute ischaemic stroke with established large infarct: multicentre, open-label, randomised trial

Recent evidence suggests a beneficial effect of endovascular thrombectomy in acute ischaemic stroke with large infarct; however, previous trials have relied on multimodal brain imaging, whereas non-contrast CT is mostly used in clinical practice. In a prospective multicentre, open-label, randomised trial, patients with acute ischaemic stroke due to large vessel occlusion in the anterior circulation and a large established infarct indicated by an Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) of 3-5 were randomly assigned using a central, web-based system (using a 1:1 ratio) to receive either endovascular thrombectomy with medical treatment or medical treatment (ie, standard of care) alone up to 12 h from stroke onset. The study was conducted in 40 hospitals in Europe and one site in Canada. The primary outcome was functional outcome across the entire range of the modified Rankin Scale at 90 days, assessed by investigators masked to treatment assignment. The primary analysis was done in the intention-to-treat population. Safety endpoints included mortality and rates of symptomatic intracranial haemorrhage and were analysed in the safety population, which included all patients based on the treatment they received. This trial is registered with ClinicalTrials.gov, NCT03094715. From July 17, 2018, to Feb 21, 2023, 253 patients were randomly assigned, with 125 patients assigned to endovascular thrombectomy and 128 to medical treatment alone. The trial was stopped early for efficacy after the first pre-planned interim analysis. At 90 days, endovascular thrombectomy was associated with a shift in the distribution of scores on the modified Rankin Scale towards better outcome (adjusted common OR 2·58 [95% CI 1·60-4·15]; p=0·0001) and with lower mortality (hazard ratio 0·67 [95% CI 0·46-0·98]; p=0·038). Symptomatic intracranial haemorrhage occurred in seven (6%) patients with thrombectomy and in six (5%) with medical treatment alone. Endovascular thrombectomy was associated with improved functional outcome and lower mortality in patients with acute ischaemic stroke from large vessel occlusion with established large infarct in a setting using non-contrast CT as the predominant imaging modality for patient selection. EU Horizon 2020.

Outcomes of Endovascular Treatment versus Standard Medical Treatment for Acute Ischemic Stroke with Basilar Artery Occlusion: A Systematic Review and Meta-Analysis.

Although endovascular treatment (EVT) is beneficial for large vessel occlusion in anterior circulation stroke, whether these benefits exist for basilar artery occlusion (BAO) remains unclear. This systematic review and meta-analysis compared the outcomes of patients with BAO undergoing EVT and standard medical treatment (SMT). The PubMed, Embase, and Cochrane Library databases were searched for eligible randomized control trials (RCTs) and non-RCTs involving patients with acute ischemic stroke and BAO undergoing EVT or SMT. The following outcomes were assessed: 90-day functional outcomes (favorable outcome and functional independence: modified Rankin scale [mRS] score of 0-3 or 0-2, respectively), mortality, and symptomatic intracranial hemorrhage (sICH) incidence. The summary effect sizes were determined as risk ratios (RRs) through the Mantel-Haenszel method with a random-effects model. Four RCTs and four non-RCTs were included. Compared with SMT, EVT resulted in a higher proportion of patients with 90-day mRS scores of 0-3 (RR: 1.54 [1.16-2.06] in RCTs and 1.88 [1.11-3.19] in non-RCTs), a higher proportion of patients achieving functional independence (90-day mRS score of 0-2; RR: 1.83 [1.07-3.12] and 1.84 [0.97-3.48], respectively), a lower risk of mortality (RR: 0.76 [0.65-0.89] and 0.72 [0.62-0.83], respectively), and a higher sICH risk (RR: 5.98 [2.11-16.97] and 4.95 [2.40-10.23], respectively). Severe neurological deficits, intravenous thrombolysis, and higher posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) were associated with EVT benefits. In patients with BAO, EVT results in superior functional outcomes, lower mortality risk, and higher sICH risk than does SMT, independent of age and sex. Higher National Institutes of Health Stroke Scale scores, intravenous thrombolysis, and higher pc-ASPECTSs before treatment are associated with greater benefits from EVT.

Safety and efficacy analysis of endovascular thrombectomy in patients with large vascular occlusion with low Alberta Stroke Program Early Computed Tomography Score

Objective: To evaluate the safety and efficacy of endovascular thrombectomy (EVT) in acute anterior circulation large vessel occlusive stroke (ALVOS) and explore the related influencing factors for prognoses in patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECT). Methods: Patients with acute ALVOS who underwent EVT in Yijishan Hospital of Wannan Medical College from January 2019 to June 2022 were sequentially enrolled. (1) Patients were divided into a low ASPECT group (0-5) and a non-low ASPECT group (6-10), and the differences between the two groups were compared with respect to incidence of perioperative complications and good prognosis rate [modified Rankin scale (mRS) score≤2] 90 days after onset. (2) According to the prognoses 90 days after onset, the low ASPECT group was divided into the good prognosis (mRS score≤2) and poor prognosis (mRS score>2) subgroup. Univariate analysis and multivariate logistic regression analysis were used to investigate the independent risk factors for prognoses of the low ASPECT patients after EVT. Results: A total of 582 patients [age 26-94(69±11) years, 345 male patients (59.3%)] were enrolled for analysis. The baseline ASPECT score was 8 (7, 10), and the baseline NIHSS score was 14 (11, 18). Among them, 102 (17.5%) patients were in the low ASPECT score group and 480 (82.5%) patients were in the non-low ASPECT score group. In the total cohort, patients in the low ASPECT score group had a higher incidence of symptomatic intracranial hemorrhage, lower 90-day good prognosis rate, and higher 90-day mortality rate. Further, propensity score matching statistical analysis showed that patients in the low ASPECT score group had a significantly higher incidence of malignant brain edema after EVT treatment (40.0% vs. 17.6%, χ2=9.13, P=0.003), and a significantly lower 90-day good prognosis rate (24.7% vs. 41.6%, χ2=4.96, P=0.026), but there was no significant difference in the incidence of symptomatic intracranial hemorrhage and 90-day mortality between the two groups (40.3% vs. 26.0%, χ2=3.55, P=0.060). Among 102 patients with low ASPECT score, 22 (21.6%) patients had good prognosis and 80 (78.4%) had poor prognosis. Multivariate logistic regression analysis showed that history of atrial fibrillation (OR=4.478, 95%CI 1.186-16.913, P=0.027) was an independent risk factor for poor prognosis of EVT in patients with low ASPECT score, while good collateral circulation (grade 2 vs. grade 0: OR=0.206, 95%CI 0.051-0.842, P=0.028) was a protective factor for good prognosis of EVT in patients with low ASPECT score. Conclusions: Although the 90-day good prognosis rate of EVT treatment for patients with low ASPECT score was lower than that of the non-low ASPECT group, 21.6% patients still benefitted from EVT treatment, especially patients with non-atrial fibrillation and good collateral circulation. Future studies involving more patients are needed to validate our observations.

Mode of Imaging Study and Endovascular Therapy for a Large Ischemic Core: Insights From the RESCUE-Japan LIMIT.

Differences in measurement of the extent of acute ischemic stroke using the Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) by non-contrast computed tomography (CT-ASPECTS stratum) and diffusion-weighted imaging (DWI-ASPECTS stratum) may impact the efficacy of endovascular therapy (EVT) in patients with a large ischemic core. The RESCUE-Japan LIMIT (Recovery by Endovascular Salvage for Cerebral Ultra-acute Embolism Japan-Large IscheMIc core Trial) was a multicenter, open-label, randomized clinical trial that evaluated the efficacy and safety of EVT in patients with ASPECTS of 3-5. CT-ASPECTS was prioritized when both CT-ASPECTS and DWI-ASPECTS were measured. The effects of EVT on the modified Rankin Scale (mRS) score at 90 days were assessed separately for each stratum. Among 183 patients, 112 (EVT group, 53; No-EVT group, 59) were in the CT-ASPECTS stratum and 71 (EVT group, 40; No-EVT group, 31) in the DWI-ASPECTS stratum. The common odds ratio (OR) (95% confidence interval) of the EVT group for one scale shift of the mRS score toward 0 was 1.29 (0.65-2.54) compared to the No-EVT group in CT-ASPECTS stratum, and 6.15 (2.46-16.3) in DWI-ASPECTS stratum with significant interaction between treatment assignment and mode of imaging study (P=0.002). There were significant interactions in the improvement of the National Institutes of Health Stroke Scale score at 48 hours (CT-ASPECTS stratum: OR, 1.95; DWIASPECTS stratum: OR, 14.5; interaction P=0.035) and mortality at 90 days (CT-ASPECTS stratum: OR, 2.07; DWI-ASPECTS stratum: OR, 0.23; interaction P=0.008). Patients with ASPECTS of 3-5 on MRI benefitted more from EVT than those with ASPECTS of 3-5 on CT.

Clinical and Safety Outcomes of Endovascular Therapy 6 to 24 Hours After Large Vessel Occlusion Ischemic Stroke With Tandem Lesions.

Effect of endovascular therapy (EVT) in acute large vessel occlusion (LVO) patients with tandem lesions (TLs) within 6-24 hours after last known well (LKW) remains unclear. We evaluated the clinical and safety outcomes among TL-LVO patients treated within 6-24 hours. This multicenter cohort was divided into two groups, based on LKW to puncture time: early window (<6 hours), and late window (6-24 hours). Primary clinical and safety outcomes were 90-day functional independence measured by the modified Rankin Scale (mRS: 0-2) and symptomatic intracranial hemorrhage (sICH). Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), first-pass effect, early neurological improvement, ordinal mRS, and in-hospital and 90-day mortality. Of 579 patients (median age 68, 32.1% females), 268 (46.3%) were treated in the late window and 311 (53.7%) in the early window. Late window group had lower median National Institutes of Health Stroke Scale score at admission, Alberta Stroke Program Early Computed Tomography Score, rates of intravenous thrombolysis, and higher rates for perfusion imaging. After adjusting for confounders, the odds of 90-day mRS 0-2 (47.7% vs. 45.0%, adjusted odds ratio [aOR] 0.71, 95% confidence interval [CI] 0.49-1.02), favorable shift in mRS (aOR 0.88, 95% CI 0.44-1.76), and sICH (3.7% vs. 5.2%, aOR 0.56, 95% CI 0.20-1.56) were similar in both groups. There was no difference in secondary outcomes. Increased time from LKW to puncture did not predicted the probability of 90-day mRS 0-2 (aOR 0.99, 95% CI 0.96-1.01, for each hour delay) among patients presenting <24 hours. EVT for acute TL-LVO treated within 6-24 hours after LKW was associated with similar rates of clinical and safety outcomes, compared to patients treated within 6 hours.

Automated Large Vessel Occlusion Detection Software and Thrombectomy Treatment Times

The benefit of endovascular stroke therapy (EVT) in large vessel occlusion (LVO) ischemic stroke is highly time dependent. Process improvements to accelerate in-hospital workflows are critical. To determine whether automated computed tomography (CT) angiogram interpretation coupled with secure group messaging can improve in-hospital EVT workflows. This cluster randomized stepped-wedge clinical trial took place from January 1, 2021, through February 27, 2022, at 4 comprehensive stroke centers (CSCs) in the greater Houston, Texas, area. All 443 participants with LVO stroke who presented through the emergency department were treated with EVT at the 4 CSCs. Exclusion criteria included patients presenting as transfers from an outside hospital (n = 158), in-hospital stroke (n = 39), and patients treated with EVT through randomization in a large core clinical trial (n = 3). Artificial intelligence (AI)-enabled automated LVO detection from CT angiogram coupled with secure messaging was activated at the 4 CSCs in a random-stepped fashion. Once activated, clinicians and radiologists received real-time alerts to their mobile phones notifying them of possible LVO within minutes of CT imaging completion. Primary outcome was the effect of AI-enabled LVO detection on door-to-groin (DTG) time and was measured using a mixed-effects linear regression model, which included a random effect for cluster (CSC) and a fixed effect for exposure status (pre-AI vs post-AI). Secondary outcomes included time from hospital arrival to intravenous tissue plasminogen activator (IV tPA) bolus in eligible patients, time from initiation of CT scan to start of EVT, and hospital length of stay. In exploratory analysis, the study team evaluated the impact of AI implementation on 90-day modified Rankin Scale disability outcomes. Among 243 patients who met inclusion criteria, 140 were treated during the unexposed period and 103 during the exposed period. Median age for the complete cohort was 70 (IQR, 58-79) years and 122 were female (50%). Median National Institutes of Health Stroke Scale score at presentation was 17 (IQR, 11-22) and the median DTG preexposure was 100 (IQR, 81-116) minutes. In mixed-effects linear regression, implementation of the AI algorithm was associated with a reduction in DTG time by 11.2 minutes (95% CI, -18.22 to -4.2). Time from CT scan initiation to EVT start fell by 9.8 minutes (95% CI, -16.9 to -2.6). There were no differences in IV tPA treatment times nor hospital length of stay. In multivariable logistic regression adjusted for age, National Institutes of Health Stroke scale score, and the Alberta Stroke Program Early CT Score, there was no difference in likelihood of functional independence (modified Rankin Scale score, 0-2; odds ratio, 1.3; 95% CI, 0.42-4.0). Automated LVO detection coupled with secure mobile phone application-based communication improved in-hospital acute ischemic stroke workflows. Software implementation was associated with clinically meaningful reductions in EVT treatment times. ClinicalTrials.gov Identifier: NCT05838456.