Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score

Image Quality Evaluation for Brain Soft Tissue in Neuroendovascular Treatment by Dose-Reduction Mode of Dual-Axis "Butterfly" Scan

BACKGROUND AND PURPOSE

Flat panel conebeam CT (CBCT) is essential for detecting hemorrhagic complications during neuroendovascular treatments. Despite its superior image quality and trajectory over conventional CBCT (circular scan), the dual-axis butterfly scan has a slightly higher radiation dose relative to conventional CBCT. This study evaluates the image quality in dose-reduction mode to uncover the appropriate radiation dose for the butterfly scan.

MATERIALS AND METHODS

We prospectively included patients who were scheduled for neuroendovascular treatment and underwent conventional CBCT and the dose-reduction mode of the butterfly scan. Two reduced radiation dose modes were used for the butterfly scan: medium-dose butterfly scan (70% of the original dose, 45 mGy) or low-dose butterfly scan (50% of the original dose, 30 mGy). The enrolled patients were assigned alternately to undergo either the medium- or low-dose butterfly scan. We evaluated and compared artifacts, contrast, and discrimination of the corticomedullary junction between conventional CBCT and one of the dose-reduction modes of the butterfly scan, with a 5-point scale scoring system.

RESULTS

Twenty patients were enrolled in each of the medium- and low-dose groups, totaling 40 patients. Compared with conventional CBCT, the medium-dose butterfly group exhibited reduced artifacts, enhanced contrast, and corticomedullary junction discrimination (except in the occipital lobe). While the low-dose butterfly group exhibited markedly reduced artifacts and improved contrast (except in the occipital lobe), a significant improvement in corticomedullary junction discrimination was not observed.

CONCLUSIONS

Even with dose reduction, the specialized trajectory of the butterfly scan enables artifact reduction, contrast improvement, and enhanced corticomedullary junction discrimination. However, the impact of the reduced dose was more noticeable, particularly in the occipital region where susceptibility to bone interference resulted in decreased contrast and compromised corticomedullary junction discrimination.

Endovascular Recanalization in Patients With Vertebral Artery Stump Syndrome: A Single-Center Experience

BACKGROUND

To evaluate the feasibility, success rate, and safety of endovascular revascularization of patients with vertebral artery stump syndrome (VASS).

METHODS

This single-center retrospective study analyzed clinical and imaging data from consecutive patients with VASS who underwent endovascular recanalization from January 2020 until June 2023.

RESULTS

Our study enrolled 30 patients [mean age 69 (range 51-84) years; 26 men]. The rate of successful technical revascularization was 96.7% (n = 29), and the rate of complications was 3.3% (n = 1). At the 6-month follow-up, the patients with successful endovascular revascularization of VASS did not have any neurological symptoms, and computed tomography angiography showed 3/29 (10.3%) re-occlusions and 4/29 (13.8%) restenosis of the stent, which was confirmed by digital subtraction angiography.

CONCLUSIONS

Endovascular recanalization in patients with VASS is feasible in selected patients and has a high procedural success rate and low rate of complications. A large, multicenter, randomized study is warranted to confirm these findings.

Automated estimation of ischemic core volume on noncontrast-enhanced CT via machine learning

BACKGROUND

Accurate estimation of ischemic core on baseline imaging has treatment implications in patients with acute ischemic stroke (AIS). Machine learning (ML) algorithms have shown promising results in estimating ischemic core using routine noncontrast computed tomography (NCCT).

OBJECTIVE

We used an ML-trained algorithm to quantify ischemic core volume on NCCT in a comparative analysis to pretreatment magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in patients with AIS.

METHODS

Patients with AIS who had both pretreatment NCCT and MRI were enrolled. An automatic segmentation ML approach was applied using Brainomix software (Oxford, UK) to segment the ischemic voxels and calculate ischemic core volume on NCCT. Ischemic core volume was also calculated on baseline MRI DWI. Comparative analysis was performed using Bland-Altman plots and Pearson correlation.

RESULTS

A total of 72 patients were included. The time-to-stroke onset time was 134.2/89.5 minutes (mean/median). The time difference between NCCT and MRI was 64.8/44.5 minutes (mean/median). In patients who presented within 1 hour from stroke onset, the ischemic core volumes were significantly (p  =  0.005) underestimated by ML-NCCT. In patients presented beyond 1 hour, the ML-NCCT estimated ischemic core volumes approximated those obtained by MRI-DWI and with significant correlation (r  =  0.56, p < 0.001).

CONCLUSION

The ischemic core volumes calculated by the described ML approach on NCCT approximate those obtained by MRI in patients with AIS who present beyond 1 hour from stroke onset.

Deep learning-based automatic ASPECTS calculation can improve diagnosis efficiency in patients with acute ischemic stroke: a multicenter study

OBJECTIVES

The Alberta Stroke Program Early CT Score (ASPECTS), a systematic method for assessing ischemic changes in acute ischemic stroke using non-contrast computed tomography (NCCT), is often interpreted relying on expert experience and can vary between readers. This study aimed to develop a clinically applicable automatic ASPECTS system employing deep learning (DL).

METHODS

This study enrolled 1987 NCCT scans that were retrospectively collected from four centers between January 2017 and October 2021. A DL-based system for automated ASPECTS assessment was trained on a development cohort (N = 1767) and validated on an independent test cohort (N = 220). The consensus of experienced physicians was regarded as a reference standard. The validity and reliability of the proposed system were assessed against physicians' readings. A real-world prospective application study with 13,399 patients was used for system validation in clinical contexts.

RESULTS

The DL-based system achieved an area under the receiver operating characteristic curve (AUC) of 84.97% and an intraclass correlation coefficient (ICC) of 0.84 for overall-level analysis on the test cohort. The system's diagnostic sensitivity was 94.61% for patients with dichotomized ASPECTS at a threshold of ≥ 6, with substantial agreement (ICC = 0.65) with expert ratings. Combining the system with physicians improved AUC from 67.43 to 89.76%, reducing diagnosis time from 130.6 ± 66.3 s to 33.3 ± 8.3 s (p < 0.001). During the application in clinical contexts, 94.0% (12,591) of scans successfully processed by the system were utilized by clinicians, and 96% of physicians acknowledged significant improvement in work efficiency.

CONCLUSION

The proposed DL-based system could accurately and rapidly determine ASPECTS, which might facilitate clinical workflow for early intervention.

CLINICAL RELEVANCE STATEMENT

The deep learning-based automated ASPECTS evaluation system can accurately and rapidly determine ASPECTS for early intervention in clinical workflows, reducing processing time for physicians by 74.8%, but still requires validation by physicians when in clinical applications.

KEY POINTS

The deep learning-based system for ASPECTS quantification has been shown to be non-inferior to expert-rated ASPECTS. This system improved the consistency of ASPECTS evaluation and reduced processing time to 33.3 seconds per scan. 94.0% of scans successfully processed by the system were utilized by clinicians during the prospective clinical application.

Safety and efficacy of bridging intravenous thrombolysis plus mechanical thrombectomy versus direct mechanical thrombectomy in different age groups of acute ischemic stroke patients

OBJECTIVE

To evaluate the safety and efficacy of bridging intravenous thrombolysis plus mechanical thrombectomy (MT) versus direct MT in different age groups of patients with acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO) of the anterior circulation.

METHODS

Consecutive patients from the prospective endovascular stroke registry of the Comprehensive Stroke Center, University of Rome Tor Vergata, Italy, between January 2015 and June 2021 were retrospectively analyzed. Patients were divided into age groups (≤ 80 years old and > 80 years old); for each age group, they were further divided in the bridging therapy group and the direct MT group. We performed a propensity score analysis according to baseline characteristics. Safety outcomes were any intracerebral hemorrhage (ICH), symptomatic ICH (sICH) and 3-month mortality. Efficacy outcomes were successful recanalization (modified Thrombolysis in Cerebral Infarction, mTICI, score ≥ 2b) and 3-month functional independence (modified Rankin Scale, mRS, ≤ 2).

RESULTS

We included 761 AIS patients with anterior circulation LVO (mean age 73.5 ± 12.8 years; 44.8% males; mean baseline NIHSS 16 ± 5). After propensity score, there were 365 patients ≤ 80 years old (52% bridging therapy) and 187 patients > 80 years old (57% bridging therapy). In both age groups of patients, we found no statistically significant differences in the rates of any ICH, sICH, successful recanalization and 3-month mortality and functional independence between bridging therapy and direct MT groups.

CONCLUSION

In our population, safety and efficacy outcomes of bridging therapy versus direct MT did not differ in both AIS patients ≤ 80 and > 80 years old.

Cerebral blood flow from arterial spin labeling as an imaging biomarker of outcome after endovascular therapy for ischemic stroke

Arterial spin labeling (ASL) is a contrast agent-free magnetic resonance imaging (MRI) technique to measure cerebral blood flow (CBF). We sought to investigate effects of CBF within the infarct on outcome and risk of hemorrhagic transformation (HT). In 111 patients (median age: 74 years, 50 men) who had undergone mechanical thrombectomy (MT) for ischemic stroke of the anterior circulation (median interval: 4 days between MT and MRI), post-stroke %CBF difference from pseudo-continuous ASL was calculated within the diffusion-weighted imaging (DWI)-positive infarct territory following lesion segmentation in relationship to the unaffected contralateral side. Functional independence was defined as a modified Rankin Scale (mRS) of 0-2 at 90 days post-stroke. %CBF difference, pre-stroke mRS, and infarct volume were independently associated with functional independence in a multivariate regression model. %CBF difference was comparable between patients with and without HT. A subcohort of 10 patients with decreased infarct-CBF despite expanded Treatment in Cerebral Infarction (eTICI) 2c or 3 recanalization was identified (likely related to the no-reflow phenomenon). Outcome was significantly worse in this group compared to the remaining cohort. In conclusion, ASL-derived %CBF difference from the DWI-positive infarct territory independently predicted functional independence, but %CBF difference was not significantly associated with an increased risk of HT.

Oxygen extraction fraction change in M1-M6 brain regions of patients with unilateral or bilateral middle cerebral artery occlusion

Cerebral blood flow (CBF) and oxygen extraction fraction (OEF) can be measured using arterial spin labeling (ASL) and quantitative susceptibility mapping (QSM) sequences, respectively. ASL and QSM sequences were performed on 13 healthy participants and 46 patients with unilateral or bilateral Middle cerebral artery (MCA) occlusion. M1-M3 and M4-M6 correspond to anterior, lateral, and posterior MCA territories within the insular ribbon and centrum semiovale, respectively. In patients with unilateral MCA occlusion, significant decreases in CBF were observed in the lesions in M1, M3, M5 and M6 regions, as well as in the contralateral M3 and M5 regions. The OEF of the lesion in the M1-M4 and M6 regions, and the contralateral M1-M3 regions were significantly higher. Additionally, the cerebral metabolic rate of oxygen (CMRO2) in the lesions of the M3 and M6 regions, and the contralateral M3 region, were significantly lower compared to the corresponding regions of healthy participants. For patients with bilateral MCA occlusion, the CMRO2 in the left M5 region and the right M3 and M6 regions were significantly lower than that in the corresponding regions of healthy participants. In conclusion, abnormal hemodynamics occur in the contralateral hemisphere of patients with unilateral MCA occlusion.

Safety and efficacy of cangrelor in endovascular thrombectomy compared with glycoprotein IIb/IIIa Inhibitors

BACKGROUND

Cangrelor, an intravenous P2Y12-receptor inhibitor, is a reversible and short-acting antithrombotic medication non-inferior to irreversible glycoprotein IIb/IIIa inhibitors (GPIs) like eptifibatide. There are insufficient data to compare the medications in endovascular thrombectomies (EVTs) requiring emergent platelet inhibition.

OBJECTIVE

To review our institution's experience with cangrelor in EVT and compares its safety and efficacy against GPIs.

METHODS

A large healthcare system retrospective review identified all patients who had received cangrelor or eptifibatide intraoperatively during EVT between December 2018 and March 2023 for this cohort study. Clinical data were reviewed. Functional status was defined by the modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS) at multiple time points. Multivariate regression was performed.

RESULTS

Of 1010 EVT patients, 36 cangrelor and 104 eptifibatide patients were selected. There were no differences in baseline function or presentations. Cangrelor was frequently administered for stenting tandem occlusions (n=16, 44.4%), and successful reperfusion occurred in 30 (83.3%) patients. On multivariate analysis, cangrelor was associated with decreased odds of hemorrhagic conversion (adjusted OR (aOR)=0.76, P=0.004) and symptomatic hemorrhage (aOR=0.86, P=0.021). There were no differences in thrombotic re-occlusion. Cangrelor was associated with a lower 24-hour NIHSS score (7.0 vs 12.0, P=0.013) and discharge NIHSS score (3.0 vs 9.0, P=0.004). There were no differences in in-hospital mortality or length of stay. Cangrelor was associated with improved odds of favorable outcome, defined as mRS score 0-2, at discharge (aOR=2.69, P=0.001) and on 90-day follow-up (aOR=2.23, P=0.031).

CONCLUSION

Cangrelor was associated with a decreased risk of hemorrhagic conversion and might lead to favorable functional outcomes for patients during hospitalization in comparison with GPIs. Prospective studies are warranted to investigate its use in EVT.

Analysis of Upper Facial Weakness in Central Facial Palsy Following Acute Ischemic Stroke

BACKGROUND

Central facial palsy (CFP), resulting from upper motor neuron lesions in the corticofacial pathway, is traditionally characterized by the sparing of the upper facial muscles. However, reports of upper facial weakness in CFP due to acute ischemic stroke have challenged this long-held assumption. This study aimed to determine the prevalence of upper facial weakness in CFP and identify its associated clinical factors.

METHODS

In this cross-sectional study, we evaluated consecutive patients with acute ischemic stroke admitted to a university hospital in Thailand from January 2022 to June 2023. Full-face video recordings were analyzed using the Sunnybrook Facial Grading System. Upper facial weakness was defined as asymmetry in at least one upper facial expression. Multivariable logistic regression was performed to identify factors associated with upper facial weakness.

RESULTS

Of 108 patients with acute ischemic stroke, 92 had CFP, and among these, 70 (76%) demonstrated upper facial weakness. Tight eye closure (force and wrinkle formation, both 42%) was the most sensitive indicator for detecting upper facial weakness. Greater stroke severity, as reflected by higher NIHSS scores (adjusted odds ratio [aOR], 1.42; 95% CI 1.07-1.88) and the presence of lower facial weakness (aOR, 6.56; 95% CI 1.85-23.29) were significantly associated with upper facial involvement. Although upper facial weakness was generally milder than lower facial weakness, its severity correlated with increasing lower facial asymmetry during movement.

CONCLUSIONS

Contrary to traditional teaching, upper facial weakness is common in CFP due to acute ischemic stroke. The severity of stroke and the presence of lower facial weakness are key predictors of upper facial involvement. These findings underscore the need for clinicians to reconsider the diagnostic paradigm, recognizing that upper facial weakness can occur in CFP. Enhanced awareness may improve diagnostic accuracy, inform treatment decisions, and ultimately lead to better patient outcomes.

Clinical feasibility of deep learning-driven magnetic resonance angiography collateral map in acute anterior circulation ischemic stroke

To validate the clinical feasibility of deep learning-driven magnetic resonance angiography (DL-driven MRA) collateral map in acute ischemic stroke. We employed a 3D multitask regression and ordinal regression deep neural network, called as 3D-MROD-Net, to generate DL-driven MRA collateral maps. Two raters graded the collateral perfusion scores of both conventional and DL-driven MRA collateral maps and measured the grading time. They also qualitatively assessed the image quality of both collateral maps. Interrater and inter-method agreements for collateral perfusion grading between the two collateral maps were analyzed, along with a comparison of grading time and image quality. In the analysis of the 296 acute ischemic stroke patients, the inter-method agreement for collateral perfusion grading was almost perfect (κ = 0.96, 95% CI: 0.95-0.98). Compared to conventional MRA collateral maps, the time taken for collateral perfusion grading on DL-driven MRA collateral maps was shorter (P < 0.001 for rater 1 and P = 0.003 for rater 2), and the image quality of the DL-driven MRA collateral maps was superior (P < 0.001 for rater 1 and P = 0.002 for rater 2). The DL-driven MRA collateral map demonstrates clinical feasibility for collateral perfusion grading in acute ischemic stroke, with the added benefits of reduced generation and interpretation time, along with improved image quality of the MRA collateral map.

A deep learning approach versus expert clinician panel in the classification of posterior circulation infarction

BACKGROUND

Posterior circulation infarction (POCI) is common. Imaging techniques such as non-contrast-CT (NCCT) and diffusion-weighted-magnetic-resonance-imaging commonly fail to detect hyperacute POCI. Studies suggest expert inspection of Computed Tomography Perfusion (CTP) improves diagnosis of POCI. In many settings, there is limited access to specialist expertise. Deep-learning has been successfully applied to automate imaging interpretation. This study aimed to develop and validate a deep-learning approach for the classification of POCI using CTP.

METHODS

Data were analysed from 3541-patients from the International-stroke-perfusion-registry (INSPIRE). All patients with baseline multimodal-CT and follow-up imaging performed at 24-48 h were identified. A cohort of 541-patients was constructed on a 1:3 POCI-to -reference-ratio for model analysis. A 3D-Dense-Convolutional-Network (DenseNet) was trained to classify patients into POCI or non-POCI using CTP-deconvolved-maps. Six-stroke-experts also independently classified patients based upon stepwise access to multimodal CT (mCT) data. DenseNet results were compared against expert clinician results. Model and clinician performance was evaluated using area-under-the-receiver-operating-curve, sensitivity, specificity, accuracy and precision. Clinician agreement was measured with the Fleiss-Kappa-statistic.

RESULTS

Best mean clinician diagnostic accuracy, sensitivity and agreement was demonstrated after review of all mCT data (AUC: 0.81, Sensitivity: 0.65, Fleiss-Kappa-statistic: 0.73). There was a spectrum of individual clinician results with an AUC-range of 0.73-0.86. Best DenseNet performance was recorded with an input combination of NCCT and delay-time maps. The DenseNet model was superior to the best mean clinician performance (AUC: 0.87) and was due to enhanced sensitivity (DenseNET: 0.77, Clinician: 0.65). The degree to which the DenseNet model outperformed each clinician ranged and was clinician specific (AUC improvement 0.01-0.14).

CONCLUSION

Comprehensive review of CTP improves diagnostic performance and agreement amongst clinicians. A DenseNet model was superior to best mean clinician performance. The degree of improvement varied by specific clinician. Development of a clinician-DenseNet approach may improve inter-clinician agreement and diagnostic accuracy. This approach may alleviate limited specialist services in resource constrained settings.

Effects of Emergent Carotid Stenting Performed before or after Mechanical Thrombectomy in the Endovascular Management of Patients with Tandem Lesions: A Multicenter Retrospective Matched Analysis

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) along with emergent carotid stent placement (eCAS) has been suggested to have a greater benefit in patients with tandem lesions (TL), compared with other strategies of treatment. Nonetheless, there is no agreement on whether the intracranial occlusion should be treated before the cervical ICA lesion, or vice versa. In this retrospective multicenter study, we sought to compare clinical and procedural outcomes of the 2 different treatment approaches in patients with TL.

MATERIALS AND METHODS

The prospective databases of 17 comprehensive stroke centers were screened for consecutive patients with TL who received MT and eCAS. Patients were divided in 2 groups based on whether they received MT before eCAS (MT-first approach) or eCAS before MT (eCAS-first approach). Propensity score matching was used to estimate the effect of the retrograde-versus-anterograde approach on procedure-related and clinical outcome measures. These included the modified TICI score 2b-3, other procedure-related parameters and adverse events after the endovascular procedure, and the ordinal distribution of the 90-day mRS scores.

RESULTS

A total of 295 consecutive patients were initially enrolled. Among them, 208 (70%) received MT before eCAS. After propensity score matching, 56 pairs of patients were available for analysis. In the matched population, the MT-first approach resulted in a higher rate of successful intracranial recanalization (91% versus 73% in the eCAS-first approach, P = .025) and a mean shorter groin-to-reperfusion time (72 [SD, 38] minutes versus 93 [SD, 50] minutes in the anterograde approach, P = .017). Despite a higher rate of efficient recanalization in the MT-first group, we did not observe a significant difference regarding the ordinal distribution of the 90-day mRS scores. Rates of procedure-related adverse events and the occurrence of both parenchymal hemorrhage types 1 and 2 were comparable.

CONCLUSIONS

Our study demonstrates that in patients with TL undergoing endovascular treatment, prioritizing the intracranial occlusion is associated with an increased rate of efficient MT and faster recanalization time. However, this strategy does not have an advantage in long-term clinical outcome. Future controlled studies are needed to determine the optimal treatment technique.

A cross-sectional study on the correlation between internal cerebral vein asymmetry and hemorrhagic transformation following endovascular thrombectomy

Introduction

Hemorrhagic transformation (HT) is a severe complication in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO) after endovascular treatment (EVT). We hypothesize that asymmetry of the internal cerebral veins (ICVs) on baseline CT angiogram (CTA) may serve as an adjunctive predictor of HT.

Methods

We conducted a study on consecutive AIS-LVO patients from November 2020 to April 2022. These patients had anterior circulation occlusions and were treated with EVT. Asymmetrical ICVs were assessed using CTA and defined as hypodensity (reduced opacification) on the ipsilateral side of occlusion compared to the contralateral side. The primary outcome was HT, defined as hemorrhage within the ischemic territory. This was evaluated using follow-up imaging (CT scan or magnetic resonance imaging) performed 48 h post-EVT. HT was classified into four subtypes based on the European Cooperative Acute Stroke Study-II criteria.

Results

A total of 126 patients were included, with an HT rate of 49.2% (62/126). ICV asymmetry was observed in 54.0% (68/126) of patients. The ICV asymmetry group exhibited a significantly higher risk of parenchymatous hematoma-type HT (33.8% vs. 15.5%, p = 0.019) and symptomatic intracerebral hemorrhage (sICH) (23.5% vs. 5.2%, p = 0.004). In multivariate logistic regression, ICV asymmetry (OR 3.809, 95% CI 1.582-9.171), baseline Alberta Stroke Program Early CT Score (OR 0.771, 95% CI 0.608-0.978), intravenous recombinant tissue plasminogen activator (OR 2.847, 95% CI 1.098-2.7.385), and poor collateral circulation (OR 3.998, 95% CI 1.572-10.169) were identified as independent risk factors of HT.

Conclusion

ICV asymmetry, likely resulting from impaired autoregulation or tissue micro-perfusion hampering cerebral blood flow (CBF), is a novel radiological sign that independently predicts HT. It is associated with a higher risk of sICH in AIS-LVO patients after EVT. Further research is warranted to validate these findings.

The e-STROKE Study: The Design of a Prospective Observational Multicentral Study

Introduction: The e-STROKE study is a prospective, multicenter observational study designed to assess the impact of various CT parameters (including e-ASPECT, CT perfusion (CTP), collateral flow status, and the size and location of the ischemic lesion) on the clinical outcomes of patients with ischemic stroke, as evaluated by the modified Rankins Scale (mRS) three months post-stroke. This study also aims to investigate whether the use of multimodal CT imaging increases the number of patients eligible for recanalization therapy. The analysis will integrate data from the RES-Q registry and radiological data from the e-STROKE system provided by Brainomix Ltd. Aims: The primary aim is to determine the predictive value of CT parameters (e-ASPECTS, CTP, collateral vessel status, and ischemic lesion volume and location) on three-month functional outcomes, as defined by the mRS, in patients with non-lacunar stroke following recanalization treatment (IVT and/or MT). The secondary aim is to evaluate whether multimodal CT examination leads to an increase in the number of patients eligible for recanalization therapy. Additionally, this study seeks to assess the specificity and sensitivity of multimodal CT in distinguishing stroke mimics from actual strokes. Methods: This multicenter observational study involves patients with suspected acute ischemic stroke and a premorbid mRS ≤ 4, who are treated with endovascular thrombectomy (EVT), intravenous thrombolysis (IVT), or managed conservatively in stroke centers within the Czech Stroke Research Network (STROCZECH), which is part of the Czech Clinical Research Infrastructure Network (CZECRIN). Data collection includes demographic, clinical, and imaging data variables such as age, sex, ethnicity, risk factors, treatment times (OTT, DNT, and OGT), TICI scores, post-treatment hemorrhage (ECAS II), mRS outcome, stroke etiology, e-ASPECTS, acute ischemic volume (AIV), thrombus length on NCCT, CTA collateral score and collateral vessel density, location of large vessel occlusion, ischemic core, hypoperfusion volume, mismatch ratio and volume, final infarct volume, hemorrhage volume, and MRI in case of negative follow-up NCCT. Conclusions: We anticipate collecting robust clinical and radiological data from approximately 2000 patients across 22 centers over a 12-month period. The results are expected to enhance the precision of diagnostic and prognostic radiological markers in managing acute stroke.

Cerebral Infarct Growth: Pathophysiology, Pragmatic Assessment, and Clinical Implications

Cerebral ischemic injury occurs when blood flow drops below a critical level, resulting in an energy failure. The progressive transformation of hypoperfused viable tissue, the ischemic penumbra, into infarction is a mechanism shared by patients with ischemic stroke if timely reperfusion is not achieved. Yet, the pace at which this transformation occurs, known as the infarct growth rate (IGR), exhibits remarkable heterogeneity among patients, brain regions, and over time, reflecting differences in compensatory collateral flow and ischemic tolerance. We review (1) the pathophysiology of infarct growth, (2) the advantages and pitfalls of different approaches of IGR measurement, (3) research gaps for future studies, and (4) the clinical implications of stroke progressor phenotypes. The estimated average IGR in patients with acute large vessel occlusion stroke is 5.4 mL/h although there is wide variability based on ischemic stroke subtype, occlusion location, presence of collaterals, and patient baseline status. The IGR can be calculated using various pragmatic strategies, mostly either quantifying the extension of the infarct at a particular time and dividing this measure by the time that elapsed from symptom onset to imaging assessment or by using collateral blood flow status as a radiological surrogate marker. The IGR defines a spectrum of clinical stroke phenotypes, often dichotomized into fast and slow progressors. An IGR ≥10 mL/h and the perfusion metric hypoperfusion intensity ratio ≥0.5 are commonly used definitions of fast progressors. A nuanced understanding of the IGR and stroke progressor phenotypes could have clinical implications, including informing prognostication, acute decision-making in peripheral-to-comprehensive transfer patients eligible for thrombectomy, and selection for adjuvant neuroprotective agents.

The treatment effect across ASPECTS in acute ischemic stroke: Analysis from the AcT trial

BACKGROUND

Early ischemic changes on baseline imaging are commonly evaluated for acute stroke decision-making and prognostication.

AIMS

We assess the association of early ischemic changes on clinical outcomes and whether it differs between intravenous tenecteplase and Alteplase.

METHODS

Data are from the phase 3, Alteplase compared to Tenecteplase (AcT) trial. Subjects with anterior circulation stroke were included. Early ischemic changes were assessed using the Alberta Stroke Program Early CT score (ASPECTS). Efficacy outcomes included modified Rankin scale (mRS) 0-1, mRS 0-2, and ordinal mRS at 90 days. Safety outcomes included 24-h symptomatic intracerebral hemorrhage (sICH), any hemorrhage on follow-up scan, and 90-day mortality rate. Mixed-effects logistic regression was used to assess the association of ASPECTS (continuous and categorical (0-4 vs 5-7 vs 8-10)) with outcomes and if these associations were modified by thrombolytic type after adjusting for age, sex, and baseline stroke severity.

RESULTS

Of the 1577 patients in the trial, 901 patients (56.3%; median age 75 years (IQR 65-84), 50.8% females, median National Institute of Health Stroke Scale (NIHSS) 14 (IQR 17-19)) with anterior circulation stroke were included. mRS 0-1 at 90 days was achieved in 1/14 (0.3%), 43/160 (14.7%), and 252/726 (85.1%) in the ASPECTS 0-4, 5-7, and 8-10 groups respectively. Every one-point decrease in ASPECTS was associated with 2.7% and 1.9% decrease in chances of mRS 0-1 and mRS 0-2 at 90 days, respectively, and 1.9% chances of increase in mortality at 90 days. Subgroup analysis in endovascular thrombectomy (EVT)-treated population showed similar results. Thrombolytic type did not modify this association between ASPECTS and 90-day mRS 0-1 (P-interaction 0.75). There was no significant interaction by thrombolytic type with any other outcomes.

CONCLUSION

Similar to prior studies, we found that every one-point decrease in ASPECTS was associated with poorer clinical and safety outcomes. This effect did not differ between alteplase and tenecteplase.

DATA ACCESS STATEMENT

Data shall made available on reasonable request from the PI (BMM).

Efficacy and safety of tirofiban in acute ischemic stroke patients with ideal reperfusion: A cohort study of LAA and CE subgroups

BACKGROUND AND OBJECTIVES

Despite achieving ideal reperfusion (eTICI = 3) through endovascular treatment (EVT), some acute ischemic stroke (AIS) patients still experience poor outcomes. This study aims to evaluate the efficacy and safety of tirofiban in AIS patients with ideal reperfusion, focusing on its effects in large artery atherosclerosis (LAA) and cardioembolic (CE) stroke.

METHODS

A total of 474 AIS patients from the RESCUE-BT database were included. Patients were assigned to either the tirofiban or placebo group based on the treatment received. The primary outcome was favorable functional recovery at 90 days (mRS ≤2), and safety outcomes included symptomatic intracranial hemorrhage (sICH) and 90-day mortality. Multivariable logistic regression was used to adjust for confounders, and subgroup and interaction analyses assessed tirofiban's efficacy in LAA and CE populations.

RESULTS

In the overall population that achieved ideal reperfusion, Tirofiban did not improve clinical outcomes and did not increase the risk of mortality or incidence of sICH (p > 0.05). However, subgroup analysis indicated potential clinical benefits for patients with higher NIHSS scores in the LAA group, especially in the subgroup with NIHSS scores >13 (adjusted OR 4.671, 95% CI [1.545, 14.122]). No significant differences were found in the CE group.

CONCLUSIONS

Tirofiban showed potential benefits for LAA patients with ideal reperfusion, especially those with NIHSS scores above 13. Careful patient selection is recommended.

Clearance rate of contrast extravasation after endovascular therapy is associated with functional outcome and mediated by cerebral edema

The brain's function of clearance and transport is closely related to the prognosis of acute ischemic stroke (AIS). In this study, we proposed a novel method, clearance rate of contrast extravasation (CROCE), to measure brain clearance and transport function in AIS patients undergoing endovascular therapy (EVT), and examined its association with cerebral edema and functional outcome. We conducted a pooled analysis of AIS patients of anterior circulation large vessel occlusion who underwent EVT in two academic hospitals. Patients who experienced contrast extravasation but not intracerebral hemorrhage following EVT were included. CROCE was defined as the mass of contrast agent cleared per hour on non-contrast CT (NCCT). Among the 215 patients finally included, we found that high CROCE was significantly associated with 90-day favorable functional outcome, and the association retained after adjustment for potential confounders. Different correlation analysis demonstrated a significant correlation between CROCE, cerebral edema, and functional outcome. Further mediation analysis revealed that cerebral edema mediated the effect of CROCE on functional outcome. These results revealed that CROCE may be a promising indicator of brain clearance function for patients who received EVT and had contrast extravasation.

Association between iron content in grey matter nuclei and functional outcome in patients with acute ischaemic stroke: A quantitative susceptibility mapping study

BACKGROUND AND PURPOSE

This study aimed to investigate the association between iron content in grey matter (GM) nuclei and functional outcome in acute ischaemic stroke (AIS) patients utilizing quantitative susceptibility mapping.

METHODS

Forty AIS patients and 40 age-, sex- and education-matched healthy controls underwent quantitative susceptibility mapping to assess susceptibility values, which are positively correlated with iron content, in the caudate nucleus, putamen, globus pallidus, thalamus, red nucleus and substantia nigra. The nuclei on the contralateral side were measured in AIS patients to minimize confounding due to oedema or haemorrhage. Functional outcome was determined by the modified Rankin Scale (mRS) score at 3 months after stroke. Poor outcome was defined as mRS >2, whilst a good outcome was defined as ≤2.

RESULTS

Susceptibility values were significantly higher in most contralateral GM nuclei in AIS patients than in the corresponding left or right nuclei in healthy controls. AIS patients with poor outcome showed significantly lower susceptibility value than those with good outcome in the contralateral caudate nucleus, but no significant differences were observed in other GM nuclei. Binary logistic regression analysis revealed a significant association between the susceptibility value of the contralateral caudate nucleus and poor outcome after adjustment for confounders (adjusted odds ratio 0.692, 95% confidence interval 0.486-0.986, p = 0.042). Receiver operating characteristic curve analysis showed an acceptable ability of the susceptibility value of the contralateral caudate nucleus to predict poor outcome (area under the curve 0.740, p = 0.013).

CONCLUSIONS

Lower iron content in the contralateral caudate nucleus was associated with poor functional outcome in AIS patients.

Effect of MR-guided perfusion imaging mismatch profiles within 6 h on endovascular thrombectomy outcomes

BACKGROUND

The treatment of acute ischemic stroke (AIS) aims to achieve early vascular recanalization and reperfusion of the penumbra. However, the effect of early penumbral imaging within 6 h on clinical outcomes remains unclear. The objective of this study was to determine the effect of magnetic resonance-guided (MR-guided) perfusion imaging within 6 h after symptom onset on endovascular thrombectomy outcomes in AIS patients.

METHODS

We prospectively collected the clinical information of consecutive AIS patients undergoing endovascular thrombectomy based on MR-guided perfusion imaging within 6 h after symptom onset from AISRNA and EVTRNA studies. The primary outcome was defined as the poor outcome (mRS > 2 within 90 days). The perfusion-weighted imaging/diffusion-weighted imaging (PWI/DWI) mismatch was assessed by an automated software.

RESULTS

We enrolled 84 patients (25 in the mismatch ≤ 1.8 group and 59 in the mismatch > 1.8 group). Significant difference was found between the mismatch > 1.8 group and the mismatch ≤ 1.8 group for the incidence of disabling stroke (mRS > 2) within 90 days (40.7% vs. 68.0%, OR: 3.099, 95% CI: 1.154-8.323, P = 0.025). Intracranial hemorrhage occurred in 8 patients (13.6%) in the mismatch > 1.8 group and 10 patients in the mismatch ≤ 1.8 group (40.0%) (P = 0.010). The risk of severe cerebral edema was 2/59 (3.4%) vs. 7/25 (28.0%) (P = 0.004). These findings remained stable after adjustment.

CONCLUSIONS

MR-guided perfusion imaging mismatch profiles within 6 h after symptom onset may be feasible to predictclinical outcomes and reduce clinically ineffective reperfusion after endovascular thrombectomy.

Penumbral Imaging to Guide Endovascular Treatment for M2 Middle Cerebral Artery Stroke

BACKGROUND

A potential benefit of mechanical thrombectomy for patients with distal medium vessel occlusions is currently being investigated in randomized trials. Computed tomography perfusion imaging has not yet been tested as a method to guide mechanical thrombectomy for distal medium vessel occlusions. The purpose of this study was to assess penumbral imaging as an imaging-based method for triaging patients with ischemic stroke and acute M2-middle cerebral artery occlusion.

METHODS

This observational retrospective study of M2-middle cerebral artery patients with ischemic stroke triaged by multimodal computed tomography undergoing mechanical thrombectomy at a high-volume stroke center between January 2015 and January 2023. The effect of recanalization was analyzed according to computed tomography perfusion-derived lesion volumes (defined using relative cerebral blood flow <30% and Tmax >6 seconds) using logistic regression analysis, and interaction terms between the independent variables and recanalization were tested. The primary end point was functional independence at day 90, defined using modified Rankin Scale scores of 0 to 2.

RESULTS

A total of 140 patients with M2-middle cerebral artery occlusion were included. In multivariable logistic regression analysis, recanalization was not associated with better functional outcome (adjusted odds ratio, 1.85 [95% CI, 0.87-3.90]; P=0.11). After including interaction terms, a significant treatment effect between recanalization and computed tomography perfusion-derived lesion volumes was observed in patients with >150 mL hypoperfusion volume (adjusted odds ratio, 1.02 [95% CI, 1.00-1.03]; P=0.007) or >125 mL penumbral volumes (adjusted odds ratio, 1.02 [95% CI, 1.01-1.03]; P=0.005), as well as for baseline ischemic core volume within the range of 15 to 40 mL (adjusted odds ratio, 1.11 [95% CI, 1.01-1.22]; P=0.03).

CONCLUSIONS

Penumbral imaging might serve as a useful tool for treatment decision-making in distal medium vessel occlusions, particularly in cases of suspected non- or codominant M2-middle cerebral artery vessel occlusions. A hypoperfusion volume threshold of >150 mL emphasizes the potential value of computed tomography perfusion as a standardized tool directly showing the volumetric relevance in distal medium vessel occlusion cases.

[Methods for determining the extent of ischemic changes in brain matter in the prognosis of clinical outcome after successful thromboextraction]

OBJECTIVE

To determine the method of primary assessment of the extent of ischemic changes of the brain matter with the greatest prognostic significance for the clinical outcome of the disease in case of successful thromboextraction (achievement of TICI 2b/3 blood flow).

MATERIAL AND METHODS

The retrospective analysis included 90 patients with ischemic stroke in the carotid system, admitted within 0 to 16 hours from the onset of the disease and performed thromboextraction with achieved TICI 2b/3 blood flow. The group with good/satisfactory functional recovery (mRS score 0-3) included 69 patients; the group with poor functional recovery/death (mRS score 4-6) included 21 patients. The study examined the prognostic significance of methods for assessing ischemic changes in native CT images (both by a doctor and using artificial intelligence) and methods for automatic cerebral perfusion analysis.

RESULTS

Based on the ROC analysis results, ROC curves were obtained corresponding to the relationship between the extent of ischemic changes in the brain matter and a good/satisfactory outcome (mRS 0-3). The largest area under the ROC curve was obtained when assessing the volume of brain matter with rCBF <30% (0.861, 95% CI 0.753-0.968, p<0.0005) and the ASPECTS score evaluated retrospectively by an expert-level physician (0.846, 95% CI 0.738-0.953, p<0.0005). When assessing the Tmax/rCBF of the mismatch, the area under the ROC curve was 0.794 (95% CI 0.639-0.949, p=0.001); for the eASPECTS score 0.764 (95% CI 0.653-0.874, p<0.0005); for the volume of the brain matter with early CT signs of ischemia 0.751 (95% CI 0.631-0.872, p=0.001); for the ASPECTS score evaluated prospectively by radiologist on duty 0.777 (95% CI 0.667-0.887, p<0.0005); for the volume of the brain matter with Tmax >6 s (0.607, 95% CI 0.457-0.757, p=0.213).

CONCLUSION

The ASPECTS score, eASPECTS, the volume of brain matter with early CT signs of ischemic changes, the volume of brain matter with rCBF <30%, as well as the Tmax/rCBF mismatch value predict the outcome of the disease with a high degree of confidence within the timeframe from 0 to 16 hours. The ASPECTS score assessed by an expert doctor and the volume of the brain substance with rCBF <30% had the greatest prognostic value for the functional outcome. The volume with a Tmax >6 s had the least predictive value. Methods for assessing brain matter using artificial intelligence algorithms (eASPECTS and volume with early signs of ischemia) showed predictive value for the functional outcome comparable to the ASPECTS score obtained by radiologists on duty in routine practice.

Risk Factors and a Prediction Model for Hemorrhagic Transformation in Acute Ischemic Stroke With Atrial Fibrillation

OBJECTIVES

To identify the risk factors of hemorrhagic transformation (HT) and to establish a prediction model for HT in patients with acute ischemic stroke (AIS) and atrial fibrillation (AF).

METHODS

From January 2015 to December 2018, patients with AIS and AF were enrolled. Demographics, lesion features, and blood test results were collected. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors of HT. The receiver operating curve (ROC) curve was utilized to determine the cutoff values and the efficiency of the variables. A predictive model was subsequently developed based on the identified independent risk factors.

RESULTS

A total of 259 patients were included. Age [odds ratio (OR): 1.094; 95% CI: 1.048-1.142; P <0.001], LDL-C (OR: 0.633; 95% CI: 0.407-0.983; P =0.042), uric acid (OR: 0.996; 95% CI: 0.991-0.999; P =0.031), Alberta Stroke Program Early CT Score (ASPECTS) (OR: 0.700; 95% CI: 0.563-0.870; P <0.001), cerebral cortex infarction (OR: 0.294; 95% CI: 0.168-0.515; P <0.001), and massive cerebral infarction (OR: 3.683; 95% CI: 3.025-5.378; P <0.001) were independently associated with HT. We have developed a model incorporating these variables. The area under the curve of the predictive model was 0.87 (95% CI: 0.83-0.92), demonstrating satisfactory predictive ability with a sensitivity of 83.5% and a specificity of 76.4%.

CONCLUSIONS

Our predictive model, which integrates age, LDL-C, uric acid, ASPECTS, cerebral cortex infarction, and massive cerebral infarction, can be used to predict HT after AIS in patients with AF, thereby facilitating the mitigation of adverse outcomes.

Prognostic serum biomarkers of synaptic, neuronal and glial injury in patients with acute ischemic stroke of the anterior circulation

BACKGROUND

We aimed to investigate the prognostic role of β-synuclein in comparison to that of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) for predicting functional outcome after acute ischemic stroke (AIS).

METHODS

We measured serum concentrations of β-synuclein, NfL and GFAP 24 h after hospital admission in 213 consecutive patients with moderate-to-severe AIS. We investigated the association between serum biomarkers and radiological/clinical characteristics, 3-months mortality and functional outcome on the modified Rankin Scale (mRS).

RESULTS

In 213 patients with AIS [mean age: 76.1 (±12.5) years, 53.1% males, median NIHSS score on admission: 13 (IQR: 9-17)], higher levels of β-synuclein, NfL and GFAP were associated with higher NIHSS scores and with lower Alberta Stroke Program CT Score (ASPECTS) points on admission. Serum β-synuclein levels was significantly correlated with NfL (rho = 0.715, p < 0.001) and GFAP concentrations (rho = 0.684, p < 0.001). The inclusion of serum β-synuclein significantly improved the accuracy of prediction models without biomarkers for overall mortality (AUC: 0.836 vs. 0.752, p < 0.001) and mRS 3-6 vs. 0-2 (AUC: 0.812 vs. 0.624, p < 0.001). Combination models with NfL and/or GFAP showed a similar accuracy.

CONCLUSIONS

Serum β-synuclein may be used to assess synaptic damage/dysfunction and to predict 3-months clinical outcomes in patients with AIS.

Predicting final infarct size and clinical outcomes in patients with acute ischemic stroke after endovascular thrombectomy using the Alberta Stroke Program early CT score on venous-phase CT

BACKGROUND

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is a semi-quantitative tool for evaluating the extent and distribution of early ischemic changes.

PURPOSE

To assess the value of ASPECTS on non-contrast CT (NCCT), arterial-phase CT (APCT), or venous-phase CT (VPCT) in predicting the final infarct core (IC) on follow-up diffusion-weighted imaging (DWI) and the clinical outcomes of patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT).

MATERIAL AND METHODS

In total, 120 patients with AIS who underwent EVT in our center were retrospectively enrolled. Correlations between CT-ASPECTS and follow-up DWI-ASPECTS were analyzed using Spearman's rank correlation coefficient. Mean differences and limit of agreement (LoA) between CT-ASPECTS and follow-up DWI-ASPECTS were assessed using the Bland-Altman plots. Multivariate logistic regression and receiver operating characteristic curve analyses were used to identify independent factors and evaluate their performances in predicting the clinical outcomes.

RESULTS

VPCT-ASPECTS exhibited the highest correlation with follow-up DWI-ASPECTS (r = 0.846, P < 0.001), followed by APCT-ASPECTS (r = 0.613, P < 0.001) and NCCT-ASPECTS (r = 0.557, P < 0.001). The mean difference between VPCT-ASPECTS and follow-up DWI-ASPECTS was 0.0 (limit of agreement = -2.1 to 2.1). National Institute of Health Stroke Scale (NIHSS) scores at admission (NIHSSpre) (odds ratio [OR]=1.162, 95% confidence interval [CI]=1.063-1.270; P = 0.001) and VPCT-ASPECTS (OR=0.728, 95% CI=0.535-0.991; P = 0.044) were the independent factors associated with clinical outcomes. The combined model integrating NIHSSpre and VPCT-ASPECTS exhibited an excellent performance in predicting good clinical outcomes (area under curve [AUC]=0.807; sensitivity=75.0%; specificity=72.3%).

CONCLUSION

VPCT-ASPECTS may be a promising imaging biomarker to predict the final IC and the clinical outcome of the patients with AIS after EVT.

Late Endovascular Treatment for Ischemic Stroke with Moderate to Large Infarct Volume is Associated with a better Clinical Prognosis

OBJECTIVE

The concept of "time is brain" is crucial for the reperfusion therapy of ischemic stroke. However, the Infarct Growth Rate (IGR) varies among individuals, which is regarded as a more powerful factor than the time when determining infarct volume and its association with clinical outcomes. For stroke patients with a similar infarct volume, a longer time from stroke Onset to Imaging (OTI) correlates with a lower IGR, which may indicate a better prognosis. This study aimed to compare the prognoses of patients with anterior circulation stroke who received Endovascular Treatment (EVT), specifically comparing early EVT vs. late EVT.

METHODS

We analyzed 255 patients with acute anterior circulation stroke due to large vessel occlusion and who have successfully undergone recanalization after EVT. All patients were divided into the late (OTI≥6 hours) and early (<6 hours) time window groups and compared. The primary outcome was moderate functional prognosis, defined as a modified Rankin Scale (mRS) ≤3 at 90 days. The secondary outcome was No Significant Infarct Expansion (NSIE), defined as a reduction of less than 2 points on the Alberta Stroke Program Early CT Score (ASPECTS).

RESULTS

In the moderate to large infarct subgroup, the late time window EVT was independently associated with a higher rate of moderate functional outcome (P =0.007) and NSIE (P =0.001); mediation analysis showed that NSIE partially mediated the effects of the late time window EVT on moderate functional outcome (coefficient: 0.112, 95% CI: 0.051 to 0.239, P =0.011); however, these associations were not consistent in the small infarct group.

CONCLUSION

For anterior circulation stroke patients who received EVT according to current guidelines, those with moderate to large infarct volume and having a longer OTI had better clinical outcomes than those who had a shorter OTI and were more suitable for EVT.

To bridge or not to bridge: The role of intravenous thrombolysis in mechanical thrombectomy for large cerebral infarctions through a two-center cohort study and meta-analysis

BACKGROUND

The effectiveness and safety of intravenous thrombolysis before mechanical thrombectomy (MT) in large cerebral infarctions remains uncertain. This study compares bridging MT, which includes intravenous thrombolysis, to direct MT without it.

METHODS

Data from 298 patients with anterior circulation large cerebral infarctions, assessed via non-enhanced CT (ASPECTS 0-5), who underwent MT in two-center cohort studies, were analyzed. Primary outcomes focused on independent ambulation (modified Rankin Scale scores 0-3) at 90 days post-stroke. Safety outcomes included parenchymal hemorrhage (PH) rates and mortality. We conducted a sensitivity analysis considering the timing from symptom onset to imaging within 4.5 hours. Additionally, a meta-analysis of 17 studies involving 3527 patients assessed the interventions' effectiveness and safety, with further scrutiny of high-quality studies (Newcastle-Ottawa Scale ratings 7-9) to increase robustness of results.

RESULTS

No significant differences were found in 90-day independent ambulation between the bridging MT and the direct MT group (adjusted odds ratio [aOR] 1.15, 95% CI 0.68-1.94). Rates of PH and mortality were also similar across groups. These outcomes were consistent in the subgroup imaged within 4.5 hours of symptom onset. The meta-analysis supported these outcomes, showing no improvement in ambulation (aOR 1.16, 95% CI 0.82-1.64) or reduction in PH with bridging MT. Further analysis of high-quality studies supported these results.

CONCLUSIONS

The cohort study and meta-analysis provide Class II evidence indicating no significant differences in functional outcomes or hemorrhagic risks between bridging and direct MT for large cerebral infarctions. This suggests that direct MT might be a viable alternative to bridging MT.

Contemporary Management of Acute Ischemic Stroke

In the past decade, adding mechanical thrombectomy (MT) of intracranial arterial occlusions to intravenous (IV) thrombolysis has revolutionized the treatment of acute ischemic stroke (AIS) by expanding the therapeutic window to 24 h. Treatment decisions require establishing a high probability of AIS; confirming time since last known well (LKW); assessing severity of the neurological deficit; determining any contraindications to IV thrombolysis; and performing neuroimaging, usually noncontrast computed tomography (NCCT), to exclude intracerebral hemorrhage. If time since LKW is less than 4.5 h, patients with disabling stroke without contraindications can proceed immediately to IV thrombolysis while the decision about MT is under way. For some patients, the MT decision can be made on the basis of clinical assessment, NCCT, and CT angiography showing a large vessel occlusion. Others may require additional neuroimaging. Patients who are not candidates for IV thrombolysis within 4.5 h or MT should be immediately evaluated for eligibility for extended-window IV thrombolysis or early antiplatelet treatment.

Follow-up ASPECTS improves prediction of potentially lethal malignant edema in patients with large middle cerebral artery stroke

BACKGROUND

Recent studies have shown that follow-up head CT is a strong predictor of functional outcomes in patients with middle cerebral artery stroke and mechanical thrombectomy. We sought to determine whether total and/or regional follow-up Alberta Stroke Program Early CT Score (ASPECTSfu) are associated with important clinical outcomes during hospitalization and improve the performance of clinical prediction models of potentially lethal malignant edema (PLME).

METHODS

We conducted a retrospective study of patients at three medical centers in a major North American metropolitan area with baseline and follow-up head CTs after large middle cerebral artery stroke between 2006 and 2022. We used multivariable logistic regression to test the association of total and regional ASPECTSfu with PLME (cerebral edema related death or surgery), adjusting for total baseline ASPECTS, age, sex, admission glucose, tissue plasminogen activator, and mechanical thrombectomy. We compared existing clinical risk models with and without total or regional ASPECTSfu using area under the curve.

RESULTS

In our 560 patient cohort, lower total ASPECTSfu was significantly associated with higher odds of PLME when adjusting for confounders (OR 1.69, 95% CI 1.49 to 2.0), and improved model discrimination compared with existing models and models using baseline ASPECTS. Deep territory involvement (OR 2.46, 95% CI 1.53 to 4.01) and anterior territory involvement (OR 3.23, 95% CI 1.88 to 5.71) were significantly associated with PLME.

CONCLUSIONS

Lower ASPECTSfu and certain locations on regional ASPECTSfu, including deep and anterior areas, were significantly associated with PLME. Including ASPECTSfu information improved discrimination of established edema prediction models and could be used immediately to help facilitate clinical management decisions and prognostication.

Predictors of parenchymal hematoma and clinical outcome after mechanical thrombectomy in patients with large ischemic core due to large vessel occlusion: a retrospective multicenter study

BACKGROUND

The aim of our study was to find predictors of parenchymal hematoma (PH) and clinical outcome after mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) and baseline large infarct.

METHODS

The databases of 16 stroke centers were retrospectively screened for patients with anterior circulation LVO and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤5 that received MT. Procedural parameters, including the number of passes during first and second technique of MT, were recorded. Outcome measures were occurrence of PH type 2 and any type of PH after MT, and the 90-day modified Rankin Scale (mRS) score of 0-3 and 0-2.

RESULTS

In total, 408 patients were available for analysis. A higher number of passes in the second technique was predictive of PH type 2 (odds ratio (OR) - 3.204, 95% confidence interval (CI) 1.140 to 9.005), whereas procedure conducted under general anesthesia was associated with lower risk (OR 0.127, 95% CI 0.002 to 0.808). The modified thrombolysis in cerebral infarction grade 2c-3 was associated with the mRS score 0-3 (OR 3.373, 95% CI 1.891 to 6.017), whereas occurrence of PH type 2 was predictive of unfavorable outcome (OR 0.221, 95% CI 0.063 to 0.773). Similar results were found for the mRS score 0-2 outcome measure.

CONCLUSION

In patients with large ischemic core, a higher number of passes during MT and procedure not conducted under general anesthesia are associated with increased rate of PH type 2, that negatively impact the clinical outcome. Our data outline a delicate balance between the need of a complete recanalization and the risk of PH following MT.

Development of a deep learning method to identify acute ischaemic stroke lesions on brain CT

BACKGROUND

CT is commonly used to image patients with ischaemic stroke but radiologist interpretation may be delayed. Machine learning techniques can provide rapid automated CT assessment but are usually developed from annotated images which necessarily limits the size and representation of development data sets. We aimed to develop a deep learning (DL) method using CT brain scans that were labelled but not annotated for the presence of ischaemic lesions.

METHODS

We designed a convolutional neural network-based DL algorithm to detect ischaemic lesions on CT. Our algorithm was trained using routinely acquired CT brain scans collected for a large multicentre international trial. These scans had previously been labelled by experts for acute and chronic appearances. We explored the impact of ischaemic lesion features, background brain appearances and timing of CT (baseline or 24-48 hour follow-up) on DL performance.

RESULTS

From 5772 CT scans of 2347 patients (median age 82), 54% had visible ischaemic lesions according to experts. Our DL method achieved 72% accuracy in detecting ischaemic lesions. Detection was better for larger (80% accuracy) or multiple (87% accuracy for two, 100% for three or more) lesions and with follow-up scans (76% accuracy vs 67% at baseline). Chronic brain conditions reduced accuracy, particularly non-stroke lesions and old stroke lesions (32% and 31% error rates, respectively).

CONCLUSION

DL methods can be designed for ischaemic lesion detection on CT using the vast quantities of routinely collected brain scans without the need for lesion annotation. Ultimately, this should lead to more robust and widely applicable methods.

Association of the Systemic Inflammation Response Index with Functional Outcome in Acute Large Vessel Occlusion Stroke Patients Receiving Mechanical Thrombectomy

Purpose

The systemic inflammation response index (SIRI) has recently emerged as a novel inflammatory and prognostic marker across various diseases. However, there is limited research examining the relationship between SIRI and 90-day functional outcome in patients with acute large vessel occlusion stroke (ALVOS) undergoing mechanical thrombectomy (MT). This study aimed to investigate the potential of SIRI as an innovative, inflammation-based predictor of 90-day functional outcome.

Methods

This retrospective cohort study consecutively recruited 604 Chinese patients with diagnosed ALVOS who underwent MT at the First College of Clinical Medical Science of China Three Gorges University between July 2017 and April 2023. Comprehensive data, including baseline demographic and clinical characteristics, were systematically extracted from electronic medical records. Poor functional outcome at 90 days was defined as modified Rankin Scale (mRS) score ≥3. We employed logistic regression models, curve fitting, sensitivity analyses, subgroup analyses, and receiver operating characteristic (ROC) curves to validate the association between SIRI and poor outcome, as well as to assess the predictive efficacy.

Results

Final analysis included 604 ALVOS subjects of whom 54.3% experienced poor functional outcome at 90 days. In the multivariate analysis, after adjusting for potential confounders, SIRI remained significantly associated with an elevated risk of poor outcomes (OR 1.18, 95% CI 1.08-1.28, P < 0.001). Nonlinear curve fitting revealed a reverse J-shaped association between SIRI and poor outcomes, with inflection points at 4.5. Subgroup analyses showed no significant interactions (all P for interaction > 0.05), However, atrial fibrillation demonstrated a significant interaction (all P for interaction = 0.001).

Conclusion

SIRI shows promise as a novel prognostic marker for 90-day functional outcome in patients with ALVOS undergoing MT. The identified nonlinear relationship and inflection point may provide valuable insights for risk stratification and clinical decision-making in this specific patient population.

Autologous mitochondrial transplant for acute cerebral ischemia: Phase 1 trial results and review

The results of a Phase 1 trial of autologous mitochondrial transplantation for the treatment of acute ischemic stroke during mechanical thrombectomy are presented. Standardized methods were used to isolate viable autologous mitochondria in the acute clinical setting, allowing for timely transplantation within the ischemic window. No significant adverse events were observed with the endovascular approach during reperfusion therapy. Safety outcomes in study participants were comparable to those of matched controls who did not undergo transplantation. This study represents the first use of mitochondrial transplantation in the human brain, highlighting specific logistical challenges related to the acute clinical setting, such as limited tissue samples and constrained time for isolation and transplantation. We also review the opportunities and challenges associated with further clinical translation of mitochondrial transplantation in the context of acute cerebral ischemia and beyond.

Stroke Evaluation in the Interventional Suite Using Dual-Layer Detector Cone-Beam CT: a First-in-human Prospective Cohort Study (the Next Generation X-ray Imaging System Trial)

PURPOSE

Cone-beam CT in the interventional suite could be an alternative to CT to shorten door-to-thrombectomy time. However, image quality in cone-beam CT is limited by artifacts and poor differentiation between gray and white matter. This study compared non-contrast brain dual-layer cone-beam CT in the interventional suite to reference standard CT in stroke patients.

METHODS

A prospective single-center study enrolled consecutive participants with ischemic or hemorrhagic stroke. The hemorrhage detection accuracy, per-region ASPECTS accuracy and subjective image quality (Likert scales for gray-white matter differentiation, structure perception and artifacts) were assessed by three neuroradiologists blinded to clinical data on dual-layer cone-beam CT 75 keV monoenergetic images compared to CT. Objective image quality was assessed by region-of-interest metrics. Non-inferiority for hemorrhage detection and ASPECTS accuracy was determined by the exact binomial test with a one-sided lower performance boundary prospectively set to 80% (98.75% CI).

RESULTS

27 participants were included (74 years ± 9; 19 female) in the hyperacute or acute stroke phase. One reader missed a small bleeding, but all hemorrhages were detected in the majority analysis (100% accuracy, CI lower boundary 86%, p = 0.002). ASPECTS majority analysis showed 90% accuracy (CI lower boundary 85%, p < 0.001). Sensitivity was 66% (individual readers 67%, 69%, and 76%), specificity was 97% (97%, 96%, 89%). Subjective and objective image quality were inferior to CT.

CONCLUSION

In a small single-center cohort, dual-layer cone-beam CT showed non-inferior hemorrhage detection and ASPECTS accuracy to CT. Despite inferior image quality, the technique may be useful for stroke evaluation in the interventional suite.

TRIAL REGISTRATION NUMBER

NCT04571099 (clinicaltrials.gov). Prospectively registered 2020-09-04.

Prognostic Value of Venous Outflow Profiles on Multiphase CT Angiography for the Patients with Acute Ischemic Stroke After Endovascular Thrombectomy

To evaluate the prognostic value of venous outflow (VO) profiles evaluated on multiphase CTA (mCTA) for the patients with acute ischemic stroke (AIS) after endovascular thrombectomy (EVT). We retrospectively collected 150 patients with AIS who underwent pre-treatment CT perfusion (CTP) evaluation and subsequent EVT from April 2018 to April 2022. Three-phases (peak arterial phase, peak venous phase, late venous phase) CTA was reconstructed from CTP raw data, and VO was evaluated on three-phases CTA, respectively. Favorable VO was regarded as a cortical vein opacification score of 3-6, and unfavorable VO as a score of 0-2. Good outcome was defined as modified Rankin Scale score of 0-2 at 90 days after EVT. Multivariate logistic regression analysis was performed to explore the predictors of good outcome. Prognostic value was assessed and compared using receiver operating characteristic (ROC) curves and Delong test. We found that good outcome was achieved in 85 (56.7%) patients. Among the mCTA-derived VO profiles, only favorable peak venous phase VO was found to be independently associated with good outcome (P < 0.001). After integrating favorable peak venous phase VO with lower post-treatment National Institute of Health Stroke Scale score at 24 hours, successful recanalization and favorable hypoperfusion intensity ratio, the predictive ability for a good outcome was significantly improved than before (area under the ROC curve; 0.947 vs 0.881; P = 0.002). This study supports that favorable peak venous VO profiles on mCTA might be a promising biomarker in predicting the good outcome in patients with AIS after EVT.

Discrepancies in ASPECTS obtained by artificial intelligence and experts: Associated factors and prognostic implications

PURPOSE

The differences between the Alberta Stroke Program Early CT Score (ASPECTS) obtained by experts and artificial intelligence (AI) software require elucidation. We aimed to characterize the discrepancies between the ASPECTS obtained by AI and experts and determine the associated factors and prognostic implications.

METHODS

This multicenter, retrospective, observational cohort study included patients showing acute ischemic stroke caused by large-vessel occlusion in the anterior circulation. ASPECTS was determined by AI software (RAPID ASPECTS) and experts from the core laboratory. Interclass correlation coefficients (ICCs) and Bland-Altman plots were used to illustrate the consistency and discrepancies; logistic regression analyses were used to assess the correlates of inconsistency; and receiver operating characteristic analyses were performed to assess the diagnostic performance for predicting unfavorable clinical outcomes.

RESULTS

The study population included 491 patients. The ICC for the expert and AI ASPECTS was 0.63 (95 % confidence interval [CI]: 0.25-0.79).The mean difference between expert and AI ASPECTS was 2.24. Chronic infarcts (odds ratio [OR], 1.9; 95 % CI, 1.1-3.4; P=0.021) and expert scores in the internal capsule (OR, 2.9; 95 % CI, 1.1-7.7; P=0.034) and lentiform (OR, 2.4; 95 % CI, 1.3-4.7; P=0.008) were significant correlates of inconsistency. The ASPECTS obtained by AI showed a significantly higher area under the curve for unfavorable outcomes (0.68 vs. 0.63, P=0.04).

CONCLUSIONS

In comparison with expert ASPECTS, AI ASPECTS overestimated the infarct extent. Future studies should aim to determine whether AI ASPECTS assessments should use a lower threshold to screen patients for endovascular therapy.

Balloon guide catheters for endovascular thrombectomy in patients with acute ischaemic stroke due to large-vessel occlusion in China (PROTECT-MT): a multicentre, open-label, blinded-endpoint, randomised controlled trial

BACKGROUND

The effectiveness of using a balloon guide catheter during endovascular thrombectomy in patients with acute ischaemic stroke due to large vessel occlusion of the anterior circulation remains uncertain. We aimed to assess the effectiveness and safety of using a balloon guide catheter during endovascular thrombectomy, compared with using a conventional guide catheter, in this patient population.

METHODS

We conducted a multicentre, open-label, blinded-endpoint, randomised controlled trial at 28 hospitals in China. Adults aged 18 years or older with acute ischaemic stroke who were able to receive endovascular thrombectomy within 24 h after symptom onset, according to local guidelines, were eligible. Patients were randomly assigned (1:1) to the balloon guide catheter group or the conventional guide catheter group using a central internet-based system with a minimisation algorithm. The treating physicians and patients were aware of treatment allocation, but clinical outcomes were collected by local trained physicians who were masked. Neurological assessments were performed at baseline, 24 h after randomisation, and at 7 days or hospital discharge (whichever occurred first). The primary outcome was functional recovery, assessed by change in modified Rankin Scale (mRS) scores (ranging from 0 [no symptoms] to 6 [death]) at 90 days in the intention-to-treat population and obtained from structured interviews. Treatment effect was estimated using ordinal logistic regression with adjustment for site and baseline prognostic factors (time from symptom onset to randomisation, the preferred thrombectomy strategy, baseline National Institutes of Health Stroke Scale score, prestroke function [estimated mRS score], and age). This trial is registered with ClinicalTrials.gov, NCT05592054 (terminated).

FINDINGS

Between Feb 7 and Nov 13, 2023, 1698 patients were assessed for eligibility and 329 were randomly assigned to the balloon guide catheter group (n=164) or conventional guide catheter group (n=165) when the trial was paused and subsequently terminated on April 18, 2024, due to safety concerns. The median age was 69 years (IQR 59-76). Of 329 patients, 201 (61%) were male and 128 (39%) were female. Participants in the balloon guide catheter group had significantly worse scores on the mRS at 90 days than those in the conventional guide catheter group (adjusted common odds ratio 0·66 [95% CI 0·45-0·98]; p=0·037). All-cause mortality at 90 days was numerically higher in the balloon guide catheter group than in the conventional guide catheter group (39 [24%] vs 26 [16%]). There were no statistically significant differences between groups in intracranial haemorrhage, symptomatic intracranial haemorrhage, or other serious adverse events.

INTERPRETATION

Compared with conventional guide catheters, the use of balloon guide catheters led to worse functional recovery in patients receiving endovascular thrombectomy for intracranial large vessel occlusion. Future studies are needed to confirm these results.

FUNDING

National Natural Science Foundation of China, Shanghai Hospital Development Center, Biopharma Industry Promotion Center Shanghai, and Ton-bridge Medical Technology.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Endovascular thrombectomy: an effective and safe therapy for perioperative ischemic stroke

Background

Perioperative ischemic stroke is a rare but devastating complication. Mechanical thrombectomy is a promising therapeutic method, but very little data is available on its efficacy and safety. This study aims to answer this question by comparing the clinical outcomes of perioperative and community-onset stroke patients after endovascular therapy.

Methods

A retrospective cohort study was conducted on a total of 35 perioperative and 584 community-onset acute ischemic stroke patients who underwent endovascular thrombectomy at our hospital over the past 3.5 years. The recanalization rate, clinical recovery and cerebral hemorrhage within 90 days after therapy were compared between these two patient groups.

Results

Endovascular thrombectomy provided perioperative and community-onset ischemic stroke patients with comparable rates of successful reperfusion (mTICI ≥2b grade) (97.1% vs. 97.3%; p = 0. 967) and favorable functional recovery (mRS ≤ 2) (51.4% vs. 43.3%, p = 0.348), with no increase in severe intracranial hemorrhage (0% vs. 2.6 and 1.0%, for hematoma ≥30% of infarcted tissue and intraventricular hemorrhage, respectively) within 90 days. In addition, perioperative stroke patients had higher prevalence of atrial fibrillation (42.9% vs. 26.7%; p = 0.038) and intracranial cerebral artery stenosis without clear embolism (17.1% vs. 3.8%; p < 0.001) than community-onset stroke patients.

Conclusion

Endovascular thrombectomy is an effective and safe therapeutic approach for patients with perioperative ischemic stroke, although the results need to be validated by further studies with larger populations. Atrial fibrillation and large artery stenosis may contribute to the pathogenesis of perioperative ischemic stroke.

Utility of the ASPECT Score for Predicting Intracranial Hemorrhage Following Intravenous Thrombolysis in Patients with Suspected MCA Infarction: Insights from the Northern Thai Stroke Registry

Purpose

 The association between the Alberta Stroke Programme Early CT Score (ASPECTS) and intracranial hemorrhage (ICH) in acute ischemic stroke (AIS) patients undergoing thrombolysis remains unclear. This study aimed to determine the relationship between ASPECTS and thrombolysis-associated outcomes, focusing on symptomatic (sICH) and asymptomatic (aICH) ICH.

Patients and methods

 AIS patients with middle cerebral artery (MCA) territory treated with thrombolysis were enrolled. Patients were categorized into favorable (8-10) and unfavorable (7 or less) ASPECTS. The primary outcomes were sICH and aICH. Secondary outcomes included ICH management, modified Rankin Scale (mRS), and mortality. Multivariable logistic regression analysis evaluated the risk of unfavorable ASPECTS and its association with study outcomes.

Results

 We included 622 patients (mean age 66.1 ± 13.5 years; 50.5% male); 95 (15.3%) had unfavorable ASPECTS. Patients with unfavorable ASPECTS had higher sICH but not aICH (21.1% vs 4.9%, P < 0.001 and 16.9% vs 17.3%, P = 1.00). Unfavorable ASPECTS was associated with sICH (adjusted odds ratio 5.1; 95% confidence interval 2.7-9.7, P < 0.001). Factors associated with lower ASPECTS included age ≥ 65 years, body weight < 60 kg, atrial fibrillation, onset-to-needle time ≥ 120 minutes, and anemia. Patients with lower ASPECTS had higher mortality and unfavorable mRS (>2) at discharge, 14 days, and 90 days (74.7% vs 50.1%, P < 0.001 for 90-day mRS >2).

Conclusion

 ASPECTS is a simple tool to predict thrombolysis-associated sICH but not aICH. Patients with unfavorable ASPECTS are at higher risk of complications and poor functional outcomes. Alternative treatments, such as mechanical thrombectomy, might be advisable for these patients.

Outcomes of mechanical thrombectomy in stroke patients with extreme large infarction core

BACKGROUND

Recent clinical trials have demonstrated that patients with large vessel occlusion (LVO) and large infarction core may still benefit from mechanical thrombectomy (MT). In this study, we evaluate outcomes of MT in LVO patients presenting with extremely large infarction core Alberta Stroke Program Early CT Score (ASPECTS 0-2).

METHODS

Data from the Stroke Thrombectomy and Aneurysm Registry (STAR) was interrogated. We identified thrombectomy patients presenting with an occlusion in the intracranial internal carotid artery (ICA) or M1 segment of the middle cerebral artery and extremely large infarction core (ASPECTS 0-2). A favorable outcome was defined by achieving a modified Rankin scale of 0-3 at 90 days post-MT. Successful recanalization was defined by achieving a modified Thrombolysis In Cerebral Ischemia (mTICI) score ≥2B.

RESULTS

We identified 58 patients who presented with ASPECTS 0-2 and underwent MT. Median age was 74.0 (66.3-80.0) years, 30 (51.7%) were females, and 16 (27.6%) patients received intravenous tissue plasminogen activator. There was no difference regarding the location of the occlusion (p=0.57). Aspiration thrombectomy was performed in 34 (64.2%) patients and stent retriever was used in 8 (15.1%) patients. In patients presenting with ASPECTS 0-2 the mortality rate was 41.4%, 31% had mRS 0-3 at day 90, 66.67% ≥70 years of age had mRS of 5-6 at day 90. On multivariable analysis, age, National Institutes of Health Stroke Scale on admission, and successful recanalization (mTICI ≥2B) were independently associated with favorable outcomes.

CONCLUSIONS

This multicentered, retrospective cohort study suggests that MT may be beneficial in a select group of patients with ASPECTS 0-2.

Predictive Value of Clinical and Dual-Energy Computed Tomography Parameters for Hemorrhagic Transformation and Long-Term Outcomes Following Endovascular Thrombectomy

OBJECTIVE

This study's objective was to explore whether certain parameters measurable by dual-energy computed tomography (DECT) performed 24 h after endovascular thrombectomy (EVT) can predict subsequent hemorrhagic transformation.

MATERIAL AND METHODS

We retrospectively reviewed patients with acute ischemic stroke (AIS) managed with EVT who had follow-up DECT within 24 h post-EVT between January 2019 and December 2023. Clinical and image parameters were recorded for predictive factor analysis. The primary outcome was hemorrhagic transformation, which was determined by using follow-up computed tomography (CT) or magnetic resonance imaging (MRI). The secondary outcomes were in-hospital mortality and 3-month post-EVT favorable functional outcome, as defined by a modified ranking scale (mRS) score of ≤2.

RESULTS

A total of 152 patients were included in this study. Multivariable analysis showed that the VNC-ASPECT score (p = 0.002) and superior sagittal sinus density (p = 0.01) were significantly associated with hemorrhagic transformation. For in-hospital survival rate analysis, post-EVT NIHSS measured 24 h post-EVT was an effective predictor, with a cutoff value of 23 (≤23: 88% vs. >23: 52.1%; p < 0.001). For functional outcome analysis, age (p < 0.001), tPA prior to EVT (p = 0.017), NIHSS 24 h post-EVT (p = 0.001), and VNC-ASPECT score (p < 0.003) were associated with a favorable functional outcome 3 months after EVT.

CONCLUSIONS

The VNC-ASPECT score was associated with both hemorrhagic transformation and a 3-month post-EVT favorable functional outcome, and could therefore be an useful predictor for the development of hemorrhagic transformation.

Characteristics and prognostic impact of unsuccessful recanalization after endovascular therapy for acute ischemic stroke

BACKGROUND

Endovascular therapy (EVT) has shown high therapeutic efficacy for acute large vessel occlusion (LVO); however, recanalization is unsuccessful in some cases. This study aimed to examine the characteristics and prognostic impact of unsuccessful recanalization after EVT compared with medical treatment alone.

METHODS

We conducted a post hoc analysis of RESCUE-Japan Registry 2, a nationwide registry of 2408 consecutive patients with acute LVO. Patients without successful recanalization after EVT (thrombolysis in cerebral infarction grade ≤ 2a) were classified into the Unsuccessful EVT group, and compared with the No-EVT group. To account for selection bias, the outcomes were compared in a propensity score-matched cohort. The outcomes included the modified Rankin Scale (mRS) score at 90 days and intracranial hemorrhage within 72 h after the LVO onset.

RESULTS

Among 188 (14.7 %) patients in the Unsuccessful EVT group out of 1281 who underwent EVT, 147 were matched with the No-EVT group, with comparable baseline characteristics. Patients in the Unsuccessful EVT group had a higher distribution of mRS score at 90 days and were less likely to achieve mRS 0-2 compared to those in the No-EVT group (23 % vs. 34 %, OR:0.58, 95 % CI:0.35-0.98). All-cause mortality was higher in the Unsuccessful EVT group (16 % vs. 6.8 %, OR: 2.54, 95 % CIs: 1.16-5.55). Symptomatic intracranial hemorrhage was more frequently observed in the Unsuccessful EVT group (5.4 % vs. 0.7 %, OR: 8.40, 95 % CIs: 1.04-68.1).

CONCLUSIONS

The clinical outcomes of patients without successful recanalization after EVT were worse than those who did not undergo EVT.

FLAIR vascular hyperintensity is associated with functional outcome in patients with ischemic stroke receiving endovascular treatment: a meta-analysis

Background

Fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) might be useful for predicting and functional outcome in ischemic stroke patients after endovascular thrombectomy (EVT), but its clinical benefit remains controversial. Thus, this study aimed to evaluate the association of FVH on prognosis in ischemic stroke patients who received EVT.

Methods

PubMed, Embase, Cochrane Library, Web of Science, and Wanfang databases were searched for potentially eligible studies published up to March 2024. Pooled standard mean difference (SMD), risk ratios (RR) with 95% confidence intervals (CI) were employed to assess the association of FVH on prognosis in ischemic stroke patients who received EVT. All statistical analyses were conducted using STATA 12.0 software.

Results

A total of 10 studies were included in our study. The results indicated that higher FVH score were associated with better prognosis (SMD: 0.80, 95% CI 0.63-0.97). Moreover, the presence of FVH was significant associated with better functional outcome in ischemic stroke patients who received EVT (RR: 0.68, 95% CI, 0.58-0.79).

Conclusion

The current meta-analysis suggests that FVH is related the prognosis of ischemic stroke patients after EVT.

Platelet-Function-Monitoring-Guided Therapy After Emergent Carotid Artery Stenting

Background/Objectives: Antiplatelet therapy after emergent carotid stenting (eCAS) represents a challenge in balancing the risk of intracerebral hemorrhages (ICHs) and in-stent thrombosis (IST). Post-procedural platelet function monitoring may guide antiplatelet therapy and could potentially improve outcomes due to fewer post-procedural complications. Methods: Consecutive eCAS patients (2019-2021) were included in a single-center retrospective observational study. Patients treated with eCAS received peri-procedural eptifibatide followed by dual antiplatelet treatment with aspirin and clopidogrel. The effect of platelet ADP inhibition by clopidogrel was monitored using the Multiplate® Analyzer (Roche). Clopidogrel non-responders were changed to ticagrelor treatment. The primary outcome was defined as a favorable outcome at 90 days using the modified Rankin Scale (mRS) of 0-2 versus 3-6. Safety outcomes included ICH, IST, and mortality. Data were analyzed and compared in clopidogrel- and ticagrelor-treated patients using Fischer's exact test and multivariate logistic regression. Results: A total of 105 patients had eCAS, and 28 patients (27%) were clopidogrel non-responders and were changed to treatment with ticagrelor. The favorable outcome was more frequent in ticagrelor-treated patients, 23 (82%), than in clopidogrel-treated patients, 44 (57%), p = 0.036. Numerically, ICH, IST, and mortality were more frequent in clopidogrel-treated patients, but none of the differences were statistically significant. In multivariate analyses, ticagrelor treatment was significantly associated with the favorable outcome, OR = 3.89 (95% CI: 1.09-13.86), p = 0.036. Conclusions: One in four eCAS patients were clopidogrel non-responders. This study suggests that personalized antiplatelet treatment therapy was safe, and that changing treatment to ticagrelor in clopidogrel non-responders was associated with better outcomes in eCAS patients.

Real-world evaluation of Brainomix e-Stroke software

BACKGROUND AND PURPOSE

Brainomix e-Stroke is an artificial intelligence-based decision support tool that aids the interpretation of CT imaging in the context of acute stroke. While e-Stroke has the potential to improve the speed and accuracy of diagnosis, real-world validation is essential. The aim of this study was to prospectively evaluate the performance of Brainomix e-Stroke in an unselected cohort of patients with suspected acute ischaemic stroke.

METHODS

The study cohort included all patients admitted to the University College London Hospital Hyperacute Stroke Unit between October 2021 and April 2022. For e-ASPECTS and e-CTA, the ground truth was determined by a neuroradiologist with access to all clinical and imaging data. For e-CTP, the values of the core infarct and ischaemic penumbra were compared with those derived from syngo.via, an alternate software used at our institution.

RESULTS

1163 studies were performed in 551 patients admitted during the study period. Of these, 1130 (97.2%) were successfully processed by e-Stroke in an average of 4 min. For identifying acute middle cerebral artery territory ischaemia, e-ASPECTS had an accuracy of 77.0% and was more specific (83.5%) than sensitive (58.6%). The accuracy for identifying hyperdense thrombus was lower (69.1%), which was mainly due to many false positives (positive predictive value of 22.9%). Identification of acute haemorrhage was highly accurate (97.8%) with a sensitivity of 100% and a specificity of 97.6%; false positives were typically caused by areas of calcification. The accuracy of e-CTA for large vessel occlusions was 91.5%. The core infarct and ischaemic penumbra volumes provided by e-CTP strongly correlated with those provided by syngo.via (ρ=0.804-0.979).

CONCLUSION

Brainomix e-Stroke software provides rapid and reliable analysis of CT imaging in the acute stroke setting although, in line with the manufacturer's guidance, it should be used as an adjunct to expert interpretation rather than a standalone decision-making tool.

Endovascular thrombectomy with or without intravenous alteplase in large-core ischemic stroke: a systematic review and meta-analysis

The role of bridging intravenous thrombolysis (IVT) with alteplase before endovascular thrombectomy (EVT) in treating large core ischemic stroke remains uncertain. We aimed to compare clinical outcomes and safety of EVT with or without bridging IVT in patients with anterior circulation large vessel occlusion (ACLVO) and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤ 5. We systematically searched PubMed, Web of Science, Cochrane Library, and Embase from inception until November 2023. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] 0-2). Secondary outcomes included 90-day independent ambulation (mRS 0-3), successful recanalization, any intracranial hemorrhage (ICH), symptomatic ICH (sICH) and 90-day mortality. A random-effects model was used for data pooling. Five high-quality studies, incorporating 2124 patients (41% treated with bridging IVT), were included. Across both unadjusted and adjusted analyses, no significant differences were found between the bridging IVT and EVT-alone groups in terms of functional independence (odds ratios [OR] = 1.36, 95% confidence interval [CI]: 0.90-2.07, P = 0.14; adjusted OR [aOR] = 1.19, 95% CI: 0.68-2.09, P = 0.53) or independent ambulation (OR = 1.14, 95% CI: 0.80-1.62, P = 0.47; aOR = 1.18, 95% CI: 1.00-1.39, P = 0.05) at 90 days. Furthermore, no differences were observed in successful recanalization, any ICH, sICH, and 90-day mortality between the two treatment groups. Bridging IVT exhibits similar functional and safety outcomes compared to EVT alone in ACLVO patients with baseline ASPECTS ≤ 5. Further research is warranted to confirm these findings.

Arterial hypotension "magnitude" and neurological outcome during mechanical thrombectomy under general anesthesia

INTRODUCTION

Mechanical thrombectomy (MT) is the standard of care for the treatment of acute ischemic stroke (AIS) with large vessel occlusion (LVO), but unfavorable outcomes remain common. Procedural arterial hypotension is associated with poor patient outcome. This study aimed to assess the impact of arterial hypotension "magnitude" (a combination of the depth, defined as the percentage relative to baseline arterial blood pressure, and the duration of hypotensive episodes)" during MT on neurological outcome.

METHODS

This is a monocentric retrospective study. Charts were reviewed between January 2018 and June 2021. "Patients were eligible if they were 18 years or older, anterior LVO was diagnosed on cerebral imaging" and MT performed under general anesthesia. Mean arterial pressure (MAP) was recorded every 5 min throughout the procedure, and the arterial hypotension "magnitude" was estimated by the area under the curve (AUC) for different thresholds of MAP drops.

MAIN OUTCOME MEASURE

The modified Rankin Scale (mRS) at 90 days.

MAIN RESULTS

Among the 117 patients analyzed, 46% had poor neurological outcome. Our study showed correlations between poor outcome and a greater procedural AUC of arterial hypotension for the different thresholds: 5% (k 0.18; 95% CI 0.06-0.30; P = 0.007), 10% (k 0.18; 95% CI 0.05-0.30; P = 0.008), 15% (k 0.18; 95% CI 0.04-0.30; P = 0.011), 20% (k 0.18; 95% CI 0.05-0.30; P = 0.010) and 30% (k 0.19; 95% CI 0.05-0.31; P = 0.010). This association persisted after controlling for age, baseline NIHSS score, and ASPECT score.

CONCLUSION

The magnitude of hypotension during MT under general anesthesia for AIS is an independent factor of poor outcome at 90 days. These associations have been observed in patients with mild and severe hypotensive episodes.