Cerebral collaterals in acute ischaemia: Implications for acute ischaemic stroke patients receiving reperfusion therapy

Intracerebral arterial blood pressure in the vasculature distal to large vessel occlusions in patients with ischemic stroke: correlation with clinical and imaging parameters

INTRODUCTION

Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke (AIS) caused by large vessel occlusions (LVO). However, our understanding of the pathophysiology of AIS is still limited, particularly regarding the ischemic microenvironment distal to the occlusion.

AIM

To investigate the relationship between the intracerebral blood pressure (BP) distal to an LVO and clinical and imaging parameters.

METHODS

In this single-center prospective study, intracerebral BPs proximal and distal to the occluding clot were measured during thrombectomy in patients with AIS of the anterior circulation caused by LVO. BPs were correlated with imaging parameters and clinical data using Spearman's rank correlation and linear regression.

RESULTS

25 patients were included. A significant correlation was found between the mean arterial pressure (MAP) distal to the occlusion and the baseline Alberta Stroke Program Early CT Score (Spearman r=0.503, P=0.014) and baseline National Institutes of Health Stroke Scale score (r=-0.439, P=0.036). No significant correlation was observed between the MAP distal to the occlusion and collateral scores (eg, MAP vs American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology score (r=0.307, P=0.165) or modified Rankin Scale (mRS) score (pre-mRS vs 90-day mRS; r=0.013, P=0.952)). Systemic MAPs did not correlate with the MAP distal to the clot (eg, R2=0.029, P=0.593).

CONCLUSION

The intracerebral BP measured in the ischemic vasculature distal to the LVO correlates with the extent of the ischemic core and the clinical severity at baseline, but not with collateral scores, systemic BPs, or functional outcome. These results shed light on the pathophysiology of BP mechanisms in AIS and can be the basis for further research in this field.

Evolucollateral dynamics in stroke: Evolutionary pathophysiology, remodelling and emerging therapeutic strategies

Leptomeningeal collaterals (LMCs) are crucial in mitigating the impact of acute ischemic stroke (AIS) by providing alternate blood flow routes when primary arteries are obstructed. This article explores the evolutionary pathophysiology of LMCs, highlighting their critical function in stroke and the genetic and molecular mechanisms governing their development and remodelling. We address the translational challenges of applying animal model findings to human clinical scenarios, emphasizing the need for further research to validate emerging therapies-such as pharmacological agents, gene therapy and mechanical interventions-in clinical settings, aimed at enhancing collateral perfusion. Computational modelling emerges as a promising method for integrating experimental data, which requires precise parameterization and empirical validation. We introduce the 'Evolucollateral Dynamics' hypothesis, proposing a novel framework that incorporates evolutionary biology principles into therapeutic strategies, offering new perspectives on enhancing collateral circulation. This hypothesis emphasizes the role of genetic predispositions and environmental influences on collateral circulation, which may impact therapeutic strategies and optimize treatment outcomes. Future research must incorporate human clinical data to create robust treatment protocols, thereby maximizing the therapeutic potential of LMCs and improving outcomes for stroke patients.

The Los Angeles Motor Scale is independently associated with cerebral blood flow < 30% volume in large vessel occlusions

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) is the treatment standard for large vessel occlusion (LVO) stroke. Under current guidelines, only patients with smaller ischemic core volumes (ICV) are eligible for MT. Thus, it is of interest to quickly estimate ICV in stroke patients. The Los Angeles Motor Scale (LAMS) is a validated tool used to assess stroke severity directly in the field. This study aims to determine whether LAMS score is also associated with ICV, as defined by the CBF <30% volume on CT perfusion imaging.

METHODS

We performed a retrospective, multicenter cohort study of consecutive patients presenting with LVO stroke from 9/1/2017 to 10/1/2023. The inclusion criteria were patients with (1) stroke caused by large vessel occlusion confirmed on CTA and (2) diagnostically adequate, multimodal pretreatment CT imaging. Demographic, clinical, and imaging data was collected through manual chart review. Both univariate and multivariate analyses were applied to assess associations. A p-value <.05 was considered significant.

RESULTS

A total of 283 patients (median age: 69, IQR: 61-78) were included in the study. On multivariate logistic regression analysis, we found that lower admission LAMS score (adjusted OR: 0.511, 95% CI: 0.313-0.834, p = .007) was independently associated with a CBF <30% volume of less than 50cc.

CONCLUSIONS

Admission LAMS is an independent predictor of a CBF <30% volume of less than 50cc. This demonstrates that LAMS can be used to estimate ICV, which will aid in the early triaging of LVO patients to thrombectomy-capable centers.

Poor venous outflow is associated with hyperintense acute reperfusion marker on follow-up MRI in patients with acute ischemic stroke with a large vessel occlusion

BACKGROUND

Hyperintense acute reperfusion marker (HARM) refers to delayed enhancement in the subarachnoid or subpial space on post-contrast fluid attenuated inversion recovery (FLAIR) images. HARM is a measure of blood-brain barrier breakdown, which has been correlated with poor outcomes in patients with acute ischemic stroke with large vessel occlusion (AIS-LVO). We hypothesized that unfavorable venous outflow (VO) would be correlated with HARM after thrombectomy treatment of AIS-LVO.

OBJECTIVE

To determine whether poor VO is associated with HARM on follow-up MRI after stroke in patients with AIS-LVO.

METHODS

Patients with AIS-LVO from the prospective CRISP2 and DEFUSE2 studies with a baseline CT angiography (CTA) scan and a follow-up MRI with FLAIR sequence were screened for enrollment. VO was measured on the baseline CTA scan using the cortical venous opacification score (COVES). HARM was determined on FLAIR sequences at the follow-up MRI. The primary outcome was the occurrence of HARM between those with good VO (VO+; COVES 3-6) and bad VO (VO-; COVES 0-2).

RESULTS

121 patients were included; 60.3% (n=73) had VO+ and 39.7% (n=48) had VO-. Patients with VO- had higher presentation National Institutes of Health Stroke Scale scores (18 (IQR 12-20) vs 12 (IQR 8-16) in VO+; P<0.001). Middle cerebral artery M1 segment occlusions were more common in VO- patients (65% vs 43% VO+; P=0.028). VO- patients also had a larger pre-treatment ischemic core (23 (4-44) mL vs 12 (3-22) mL in VO+; P=0.049) and Tmax >6 s volumes (105 (72-142) mL vs 66 (35-95) mL in VO+; P<0.001). VO- patients were more likely to develop HARM after thrombectomy (31% vs 10% in VO+; P=0.003). On multivariable regression analysis, VO- (OR=3.6 (95% CI 1.2 to 10.6); P=0.02) and the presence of any ICH (OR=3.6 (95% CI 1.2 to 10.5); P=0.02) were independently associated with the occurrence of HARM.

CONCLUSIONS

In patients with AIS-LVO, VO- correlated with HARM on post-thrombectomy MRI.

Thrombectomy improves functional independence in severe basilar artery occlusion with favorable collateral circulation

BACKGROUND AND PURPOSE

This study aimed to investigate the effect of collateral circulation on the outcomes of thrombectomy versus medical management alone in basilar artery occlusion (BAO) patients with varying stroke severities.

METHODS

Data from the ATTENTION cohort were used to perform a post-hoc analysis comparing the outcomes of thrombectomy with medical management in BAO patients with varying degrees of collateral circulation and stroke severity. Basilar Artery on Computed Tomography Angiography (BATMAN) scores were used to quantify the collateral circulation, and the effect was estimated through a primary outcome of 90-day functional independence (modified Rankin Scale score, mRS ≤2). Favorable versus unfavorable BATMAN scores were analyzed as both continuous and categorical variables, and an adjusted multivariate regression model was applied.

RESULTS

Among 221 BAO patients, thrombectomy significantly improved functional independence compared to medical management in patients with favorable BATMAN scores (aOR 7.75, 95% CI 2.78-26.1), but not in those with unfavorable BATMAN scores (aOR 1.33, 95% CI 0.28-6.92; pinteraction = 0.028). When treated as a continuous variable, increased BATMAN score was found to be associated with a higher likelihood of functional independence in the thrombectomy group (aOR 1.97, 95% CI 1.44-2.81; pinteraction = 0.053). In severe stroke patients with higher BATMAN scores (National Institutes of Health Stroke Scale (NIHSS) ≥21), we identified a significant interaction for treatment effect with thrombectomy compared to medical management (pinteraction = 0.042).

CONCLUSION

An increased BATMAN score was significantly associated with a higher probability of functional independence after thrombectomy than after medical management, particularly in patients with severe BAO.

A clinical and computed tomography-based nomogram to predict the outcome in patients with anterior circulation large vessel occlusion after endovascular mechanical thrombectomy

PURPOSE

To explore the positive predictors of the clinical outcome in acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (ACLVO) after endovascular mechanical thrombectomy (EMT) at a 90-day follow-up, and to establish a nomogram model to predict the clinical outcome.

MATERIALS AND METHODS

AIS patients with ACLVO detected by multimodal Computed Tomography imaging who underwent EMT were collected. Patients were divided into the favorable and the unfavorable groups according to the 90-day modified Rankin Scale (mRS) score. Univariate and multivariate analyses were performed to investigate predictors of the favorable outcome (mRS of 0-2). A nomogram model for predicting the clinical outcome after EMT was drawn, and the receiver operating characteristic (ROC) curve was used to evaluate its predictive value.

RESULTS

Totally 105 patients including 65 patients in the favorable group and 40 in the unfavorable group were enrolled. Multivariate logistic regression analysis showed that admission National Institute of Health Stroke scale (NIHSS) score [0.858 (95% CI 0.778-0.947)], ACLVO at M2 [20.023 (95% CI 2.204-181.907)] and infarct core (IC) volume [0.943 (95% CI 0.917-0.969)] was positively correlated with favorable outcome. The accuracy of the nomogram model in predicting the outcome was 0.923 (95% CI 0.870-0.976), with a cutoff value of 119.6 points. The area under the ROC curve was 0.848 (95% CI 0.780-0.917; sensitivity, 79.7%; specificity, 90.0%).

CONCLUSION

A low Admission NIHSS score, ACLVO at M2, and a small IC volume were positive predictors for favorable outcome. The nomogram model may well predict the outcome in AIS patients with ACLVO after EMT.

Hypoperfusion Intensity Ratio as an Indirect Imaging Surrogate in Patients With Anterior Circulation Large-Vessel Occlusion and Association of Baseline Characteristics With Poor Collateral Status

BACKGROUND

Collateral status (CS) plays a crucial role in infarct growth rate, risk of postthrombectomy hemorrhage, and overall clinical outcomes in patients with acute ischemic stroke (AIS) secondary to anterior circulation large-vessel occlusions (LVOs). Hypoperfusion intensity ratio has been previously validated as an indirect noninvasive pretreatment imaging biomarker of CS. In addition to imaging, derangements in admission laboratory findings can also influence outcomes in patients with AIS-LVO. Therefore, our study aims to assess the relationship between admission laboratory findings, baseline characteristics, and CS, as assessed by hypoperfusion intensity ratio in patients with AIS-LVO.

METHODS AND RESULTS

In this retrospective study, consecutive patients presenting with AIS secondary to anterior circulation LVO who underwent pretreatment computed tomography perfusion were included. The computed tomography perfusion data processed by RAPID (Ischema View, Menlo Park, CA) generated the hypoperfusion intensity ratio. Binary logistic regression models were used to assess the relationship between patients' baseline characteristics, admission laboratory findings, and poor CS. A total of 221 consecutive patients with AIS-LVO between January 2017 and September 2022 were included in our study (mean±SD age, 67.0±15.8 years; 119 men [53.8%]). Multivariable logistic regression showed that patients with AIS caused by cardioembolic and cryptogenic causes (adjusted odds ratio [OR], 2.67; 95% CI, 1.20-5.97; P=0.016), those who presented with admission National Institutes of Health Stroke Scale score ≥12 (adjusted OR, 3.12; 95% CI, 1.61-6.04; P=0.001), and male patients (adjusted OR, 2.06; 95% CI, 1.13-3.77; P=0.018) were associated with poor CS.

CONCLUSIONS

Stroke caused by cardioembolic or cryptogenic causes, admission National Institutes of Health Stroke Scale score of ≥12, and male sex were associated with poor CS, as defined by hypoperfusion intensity ratio in the patients with AIS-LVO.

Communicating Arteries and Leptomeningeal Collaterals: A Synergistic but Independent Effect on Patient Outcomes after Stroke

The collateral system is a compensatory mechanism activated in the acute phase of an ischemic stroke. It increases brain perfusion to the hypoperfused area. Arteries of the Willis' circle supply antegrade blood flow, while pial (leptomeningeal) arteries direct blood via retrograde flow. The aim of our retrospective study was to investigate the relationship between both collateral systems, computed tomography perfusion (CTP) values, and functional outcomes in acute stroke patients. Overall, 158 patients with anterior circulation stroke who underwent mechanical thrombectomy were included in the study. We analyzed the presence of communicating arteries and leptomeningeal arteries on computed tomography angiography. Patients were divided into three groups according to their collateral status. The main outcomes were the rate of functional independence 3 months after stroke (modified Rankin scale score, mRS) and mortality rate. Our study suggests that the collateral status, as indicated by the three groups (unfavorable, intermediate, and favorable), is linked to CT perfusion parameters, potential recuperation ratio, and stroke outcomes. Patients with favorable collateral status exhibited smaller core infarct and penumbra volumes, higher mismatch ratios, better potential for recuperation, and improved functional outcomes compared to patients with unfavorable or intermediate collateral status.

Introducing the Futile Recanalization Prediction Score (FRPS): A Novel Approach to Predict and Mitigate Ineffective Recanalization after Endovascular Treatment of Acute Ischemic Stroke

Objective: This study aims to develop and validate the Futile Recanalization Prediction Score (FRPS), a novel tool designed to predict the severity risk of FR and aid in pre- and post-EVT risk assessments. Methods: The FRPS was developed using a rigorous process involving the selection of predictor variables based on clinical relevance and potential impact. Initial equations were derived from previous meta-analyses and refined using various statistical techniques. We employed machine learning algorithms, specifically random forest regression, to capture nonlinear relationships and enhance model performance. Cross-validation with five folds was used to assess generalizability and model fit. Results: The final FRPS model included variables such as age, sex, atrial fibrillation (AF), hypertension (HTN), diabetes mellitus (DM), hyperlipidemia, cognitive impairment, pre-stroke modified Rankin Scale (mRS), systolic blood pressure (SBP), onset-to-puncture time, sICH, and NIHSS score. The random forest model achieved a mean R-squared value of approximately 0.992. Severity ranges for FRPS scores were defined as mild (FRPS < 66), moderate (FRPS 66-80), and severe (FRPS > 80). Conclusions: The FRPS provides valuable insights for treatment planning and patient management by predicting the severity risk of FR. This tool may improve the identification of candidates most likely to benefit from EVT and enhance prognostic accuracy post-EVT. Further clinical validation in diverse settings is warranted to assess its effectiveness and reliability.

Effect of heart rate on poor outcome in stroke patients treated with intra-arterial thrombectomy

BACKGROUND AND PURPOSE

The relationship between heart rate and the prognosis of patients with large vessel occlusion strokes treated with mechanical thrombectomy (MT) is not well established. This study aimed to evaluate the association of mean heart rate and heart rate variability (HRV) with the clinical outcomes after MT therapy.

METHODS

Acute ischemic stroke patients undergoing MT therapy were prospectively recruited from March 2020 to November 2022. Their heart rate was collected every hour for the initial 72 h after MT procedure, and the variability of heart rate was measured by standard deviation (SD) and coefficient of variation (CV). All-cause mortality and worsening of functional outcome (change in modified Rankin Scale (mRS) score) at 3-month were captured. Binary logistic regression was used to evaluate the association between heart rate indicators and all-cause mortality. Ordinal logistic regression was used to evaluate the association between heart rate indicators and worsening of functional outcome.

RESULTS

Among 191 MT-treated patients, 51(26.7%) patients died at 3-month after stroke. Increased mean heart rate per 10-bpm, heart rate SD and CV per 5-unit were all associated with the increased risk of mortality (adjusted hazard ratio [aHR] with 95% CI: 1.29 [1.09-1.51], 1.19 [1.07-1.32], 1.14 [1.03-1.27]; respectively). Patients in the highest tertile of heart rate SD had an increased risk of mortality (4.62, 1.70-12.52). After using mRS as a continuous variable, we found increased mean heart rate per 10-bpm, heart rate SD and CV per 5-unit were associated with the worsening of functional outcome (adjusted odds ratio [aOR] with 95% CI: 1.35 [1.11-1.64], 1.27 [1.05-1.53], 1.19 [1.02-1.40]; respectively). A linear relationship was observed between mean heart rate or heart rate SD and mortality; while all of the heart rate measures in this study showed a linear relationship with the worsening of functional outcome.

CONCLUSIONS

Higher mean heart rate and HRV were associated with the increased risk of 3-month all-cause mortality and worse functional outcome after MT therapy for AIS patients.

Utilizing imaging parameters for functional outcome prediction in acute ischemic stroke: A machine learning study

BACKGROUND AND PURPOSE

We aimed to predict the functional outcome of acute ischemic stroke patients with anterior circulation large vessel occlusions (LVOs), irrespective of how they were treated or the severity of the stroke at admission, by only using imaging parameters in machine learning models.

METHODS

Consecutive adult patients with anterior circulation LVOs who were scanned with CT angiography (CTA) and CT perfusion were queried in this single-center, retrospective study. The favorable outcome was defined as a modified Rankin score (mRS) of 0-2 at 90 days. Predictor variables included only imaging parameters. CatBoost, XGBoost, and Random Forest were employed. Algorithms were evaluated using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), accuracy, Brier score, recall, and precision. SHapley Additive exPlanations were implemented.

RESULTS

A total of 180 patients (102 female) were included, with a median age of 69.5. Ninety-two patients had an mRS between 0 and 2. The best algorithm in terms of AUROC was XGBoost (0.91). Furthermore, the XGBoost model exhibited a precision of 0.72, a recall of 0.81, an AUPRC of 0.83, an accuracy of 0.78, and a Brier score of 0.17. Multiphase CTA collateral score was the most significant feature in predicting the outcome.

CONCLUSIONS

Using only imaging parameters, our model had an AUROC of 0.91 which was superior to most previous studies, indicating that imaging parameters may be as accurate as conventional predictors. The multiphase CTA collateral score was the most predictive variable, highlighting the importance of collaterals.

Deep Learning-Based Synthetic TOF-MRA Generation Using Time-Resolved MRA in Fast Stroke Imaging

BACKGROUND AND PURPOSE

Time-resolved MRA enables collateral evaluation in acute ischemic stroke with large-vessel occlusion; however, a low SNR and spatial resolution impede the diagnosis of vascular occlusion. We developed a CycleGAN-based deep learning model to generate high-resolution synthetic TOF-MRA images using time-resolved MRA and evaluated its image quality and clinical efficacy.

MATERIALS AND METHODS

This retrospective, single-center study included 397 patients who underwent both TOF- and time-resolved MRA between April 2021 and January 2022. Patients were divided into 2 groups for model development and image-quality validation. Image quality was evaluated qualitatively and quantitatively with 3 sequences. A multireader diagnostic optimality evaluation was performed by 16 radiologists. For clinical validation, we evaluated 123 patients who underwent fast stroke MR imaging to assess acute ischemic stroke. The diagnostic confidence level and decision time for large-vessel occlusion were also evaluated.

RESULTS

Median values of overall image quality, noise, sharpness, venous contamination, and SNR for M1, M2, the basilar artery, and posterior cerebral artery are better with synthetic TOF than with time-resolved MRA. However, with respect to real TOF, synthetic TOF presents worse median values of overall image quality, sharpness, vascular conspicuity, and SNR for M3, the basilar artery, and the posterior cerebral artery. During the multireader evaluation, radiologists could not discriminate synthetic TOF images from TOF images. During clinical validation, both readers demonstrated increases in diagnostic confidence levels and decreases in decision time.

CONCLUSIONS

A CycleGAN-based deep learning model was developed to generate synthetic TOF from time-resolved MRA. Synthetic TOF can potentially assist in the detection of large-vessel occlusion in stroke centers using time-resolved MRA.

Angiographic collateral venous phase: a novel landmark for leptomeningeal collaterals evaluation in acute ischemic stroke

BACKGROUND

Although recanalization rates constantly increase (>80%), a favorable clinical outcome is achieved in only 45-55% of patients undergoing mechanical thrombectomy (MT) for anterior circulation stroke. Collateral circulation seems to play a major role in determining this discrepancy. The aim of the study was to investigate a novel angiographic landmark assessing the collateral venous phase (CVP) compared with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) score, based on the arterial collateral assessment.

METHODS

Two hundred patients with anterior circulation stroke treated by MT between 2016 and 2021 were included. The ASITN/SIR score and the presence of CVP were blindly evaluated by expert neuroradiologists. Three subanalyses were performed comparing patients with good versus poor collaterals, CVP presence versus absence, and a composite analysis including both ASITN/SIR and CVP grading results.

RESULTS

Good collateral circulation (ASITN >2) was observed in 113 patients (56.5%) whereas CVP was present in 90 patients (45%) and mostly in patients with good collaterals. Favorable clinical and neuroradiological outcomes were more likely observed in patients with both good collaterals and the presence of CVP than in those with good collaterals and absence of CVP (modified Rankin Scale score 0-2: 77.3% vs 7.9%, p<0.0001; mortality: 9.3% vs 26.3%, p=0.02; 24-hour Alberta Stroke Program Early CT Score: 8 vs 6, p<0.0001), while ASITN/SIR score alone was not significantly associated with clinical outcomes.

CONCLUSIONS

The presence of CVP improves the angiographic assessment of collateral circulation. CVP could be proposed as a new imaging landmark to better understand the functionality of collaterals.

Comprehensive Meta-Analysis of Futile Recanalization in Acute Ischemic Stroke Patients Undergoing Endovascular Thrombectomy: Prevalence, Factors, and Clinical Outcomes

BACKGROUND

Futile recanalization (FR) continues to raise concern despite the success of endovascular thrombectomy (EVT) in acute ischemic stroke (AIS). Understanding the prevalence of FR and identifying associated factors are crucial for refining patient prognoses and optimizing management strategies.

OBJECTIVES

This study aims to comprehensively assess the pooled prevalence of FR, explore the diverse factors connected with FR, and establish the association of FR with long-term clinical outcomes among AIS patients undergoing EVT.

MATERIALS AND METHODS

Incorporating studies focusing on FR following EVT in AIS patients, we conducted a random-effect meta-analysis to assess the pooled prevalence and its association with various clinical and imaging risk factors linked to FR. Summary estimates were compiled and study heterogeneity was explored.

RESULTS

Our comprehensive meta-analysis, involving 11,700 AIS patients undergoing EVT, revealed a significant pooled prevalence of FR at 51%, with a range of 48% to 54% (Effect Size [ES]: 51%; 95% Confidence Interval [CI]: 48-54%; z = 47.66; p < 0.001). Numerous clinical factors demonstrated robust correlations with FR, including atrial fibrillation (Odds Ratio [OR]: 1.39, 95% CI 1.22 1.59; p < 0.001), hypertension (OR 1.65, 95% CI 1.41 1.92; p < 0.001), diabetes mellitus (OR 1.71, 95% CI 1.47 1.99; p < 0.001), previous stroke or transient ischemic attack (OR 1.298, 95% CI 1.06 1.59; p = 0.012), prior anticoagulant usage (OR 1.33, 95% CI 1.08 1.63; p = 0.007), cardioembolic strokes (OR 1.34, 95% CI 1.10 1.63; p = 0.003), and general anesthesia (OR 1.53, 95% CI 1.35 1.74; p < 0.001). Conversely, FR exhibited reduced likelihoods of smoking (OR 0.66, 95% CI 0.57 0.77; p < 0.001), good collaterals (OR 0.33, 95% CI 0.23 0.49; p < 0.001), male sex (OR 0.87, 95% CI 0.77 0.97; p = 0.016), and intravenous thrombolysis (IVT) (OR 0.75, 95% CI 0.66 0.86; p < 0.001). FR was strongly associated with increasing age (standardized mean difference [SMD] 0.49, 95% CI 0.42 0.56; p < 0.0001), baseline systolic blood pressure (SMD 0.20, 95% CI 0.13 0.27; p < 0.001), baseline National Institute of Health Stroke Severity Score (SMD 0.75, 95% CI: 0.65 0.86; p < 0.001), onset-to-treatment time (SMD 0.217, 95% CI 0.13 0.30; p < 0.001), onset-to-recanalization time (SMD 0.38, 95% CI 0.19; 0.57; p < 0.001), and baseline blood glucose (SMD 0.31, 95% CI 0.22 0.41; p < 0.001), while displaying a negative association with reduced baseline Alberta Stroke Program Early CT Score (ASPECTS) (SMD -0.37, 95% CI -0.46 -0.27; p < 0.001). Regarding clinical outcomes, FR was significantly associated with increased odds of symptomatic intracranial hemorrhages (OR 7.37, 95% CI 4.89 11.12; p < 0.001), hemorrhagic transformations (OR 2.98, 95% CI 2.37 3.75; p < 0.001), and 90-day mortality (OR 19.24, 95% CI 1.57 235.18; p = 0.021).

CONCLUSIONS

The substantial prevalence of FR, standing at approximately 51%, warrants clinical consideration. These findings underscore the complexity of FR in AIS patients and highlight the importance of tailoring management strategies based on individual risk factors and clinical profiles.

Integrative Approaches in Acute Ischemic Stroke: From Symptom Recognition to Future Innovations

Among the high prevalence of cerebrovascular diseases nowadays, acute ischemic stroke stands out, representing a significant worldwide health issue with important socio-economic implications. Prompt diagnosis and intervention are important milestones for the management of this multifaceted pathology, making understanding the various stroke-onset symptoms crucial. A key role in acute ischemic stroke management is emphasizing the essential role of a multi-disciplinary team, therefore, increasing the efficiency of recognition and treatment. Neuroimaging and neuroradiology have evolved dramatically over the years, with multiple approaches that provide a higher understanding of the morphological aspects as well as timely recognition of cerebral artery occlusions for effective therapy planning. Regarding the treatment matter, the pharmacological approach, particularly fibrinolytic therapy, has its merits and challenges. Endovascular thrombectomy, a game-changer in stroke management, has witnessed significant advances, with technologies like stent retrievers and aspiration catheters playing pivotal roles. For select patients, combining pharmacological and endovascular strategies offers evidence-backed benefits. The aim of our comprehensive study on acute ischemic stroke is to efficiently compare the current therapies, recognize novel possibilities from the literature, and describe the state of the art in the interdisciplinary approach to acute ischemic stroke. As we aspire for holistic patient management, the emphasis is not just on medical intervention but also on physical therapy, mental health, and community engagement. The future holds promising innovations, with artificial intelligence poised to reshape stroke diagnostics and treatments. Bridging the gap between groundbreaking research and clinical practice remains a challenge, urging continuous collaboration and research.

Inter-Rater Reliability of Collateral Status Assessment Based on CT Angiography: A Retrospective Study of Middle Cerebral Artery Ischaemic Stroke

The importance of assessing the collateral status (CS) in patients with ischaemic stroke (IS) has repeatedly been emphasised in clinical guidelines. Various publications offer qualitative or semiquantitative scales with gradations corresponding to the different extents of the collaterals, visualised mostly on the basis of CTA images. However, information on their inter-rater reliability is limited. Therefore, the aim of this study is to investigate the inter-rater reliability of the scales for collateral assessment. CTA images of 158 patients in the acute period of IS were used in the study. The assessment of CS was performed by two experts using three methodologies: the modified Tan scale, the Miteff scale, and the Rosenthal scale. Cohen's kappa, weighted kappa and Krippendorff's alpha were used as reliability measures. For the modified Tan scale and the Miteff and Rosenthal scales, the weighted kappa values were 0.72, 0.49 and 0.59, respectively. Although the best measure of consistency was found for the modified Tan scale, no statistically significant differences were revealed among the scales. The impact of the CS on the degree of neurological deficit at discharge was shown for the modified Tan and Rosenthal scales. In conclusion, the analysis showed a moderate inter-rater reliability of the three scales, but was not able to distinguish the best one among them.

Prognostic accuracy and impact of cerebral collateral status on clinical and safety outcomes in acute ischemic stroke patients receiving reperfusion therapy: a systematic meta-analysis

BACKGROUND

Cerebral collateral status has a potential role in mediating postreperfusion clinical and safety outcomes in acute ischemic stroke (AIS).

PURPOSE

To investigate the prognostic accuracy and impact of collateral status on clinical and safety outcomes in patients with AIS receiving reperfusion therapy.

MATERIAL AND METHODS

Studies with AIS patients treated with reperfusion therapy, collateral status assessed using Tan, ASITN/SIR, or similar collateral grading methods and data stratified according to collateral status were included. Relevant data on clinical outcomes, such as functional outcome at 90 days, mortality at 90 days, angiographic reperfusion, symptomatic intracerebral hemorrhage (sICH) and hemorrhagic transformation (HT), were collated and analyzed.

RESULTS

A meta-analysis of 18 studies involving 4132 patients with AIS was conducted. Good collateral status was significantly associated with angiographic reperfusion (odds ratio [OR]=1.97, 95% confidence interval [CI]=1.38-2.80; P < 0.0001), sICH (OR=0.67, 95% CI=0.46-0.99; P = 0.042), and 90-day functional outcome (OR=3.05, 95% CI=1.78-5.24; P < 0.0001). However, its association with HT (OR=0.76, 95% CI=0.38-1.51; P = 0.425) and three-month mortality (OR=0.53, 95% CI=0.17-1.69; P = 0.280) did not reach statistical significance. The prognostic accuracy of collaterals for predicting angiographic reperfusion, HT, functional outcome (at 90 days), and mortality (at 90 days) were 63%, 49%, 66%, and 48%, respectively.

CONCLUSION

Cerebral collaterals are significantly associated with clinical and safety outcomes, albeit with a prognostic accuracy range of 48%-66%; thus, evaluation of their patency is a useful prognostic tool in patients with AIS receiving reperfusion therapy.

An Equity and Justice-Informed Ethical Framework to Guide Incidental Findings in Brain Imaging Research

The handling of incidental findings (IFs) in brain imaging studies has been a source of contention among scientists and bioethicists. A conceptual framework informed by diversity, equity, and inclusion (DEI) and distributive justice approaches, namely EUSTICE, is proposed for the ethical handling and reporting of IFs in brain imaging research. I argue that EUSTICE provides a systematic and inclusive approach to addressing the ethical conundrum around IF disclosure and managing IFs proportionately and sensitively in brain imaging research. The EUSTICE framework may have implications for the field of neurosciences or human studies broadly in guiding ethics of IFs in research.

Effect of intravenous thrombolysis before endovascular therapy on outcome according to collateral status: insight from the ETIS Registry

BACKGROUND

It is unknown whether collateral status modifies the effect of pretreatment intravenous thrombolysis (IVT) on the outcomes of patients with large vessel occlusions treated with endovascular therapy (EVT). We aimed to assess whether collateral status modifies the effect of IVT on the outcomes of EVT in clinical practice.

METHODS

We used data from the ongoing prospective multicentric Endovascular Treatment in Ischemic Stroke (ETIS) Registry in France. Patients with anterior circulation proximal large vessel occlusions treated with EVT within 6 hours of symptom onset were enrolled. Patients were divided into two groups based on pretreatment with IVT. The two groups were matched based on baseline characteristics. We tested the interaction between collateral status and IVT in unadjusted and adjusted models.

RESULTS

A total of 1589 patients were enrolled in the study, of whom 55% received IVT. Using a propensity score matching method, 724 no IVT patients were matched to 549 IVT patients. In propensity score weighted analysis, IVT was associated with higher odds of early neurological improvement (OR 1.74; 95% CI 1.33 to 2.26), favorable functional outcome (OR 1.66; 95% CI 1.23 to 2.24), excellent functional outcome (OR 2.04; 95% CI 1.47 to 2.83), and successful reperfusion (OR 2.18; 95% CI 1.51 to 3.16). IVT was not associated with mortality or hemorrhagic complications. There was no interaction between collateral status and IVT association with any of the outcomes.

CONCLUSIONS

Collateral status does not modify the effect of pretreatment IVT on the efficacy and safety outcomes of EVT.

When Two Maladies Meet: Disease Burden and Pathophysiology of Stroke in Cancer

Stroke and cancer are disabling diseases with an enormous global burden, disproportionately affecting vulnerable populations and low- and middle-income countries. Both these diseases share common risk factors, which warrant concerted attention toward reshaping population health approaches and the conducting of fundamental studies. In this article, an overview of epidemiological trends in the prevalence and burden of cancer and stroke, underlying biological mechanisms and clinical risk factors, and various tools available for risk prediction and prognosis are provided. Finally, future recommendations for research and existing gaps in our understanding of pathophysiology. Further research must investigate the causes that predispose patients to an increased risk of stroke and/or cancer, as well as biomarkers that can be used to predict growing morbidity and mortality.

Association of Lesion Topography with Functional Outcomes in Acute Ischemic Stroke Patients Considered for, or Receiving, Reperfusion Therapy: A Meta-Analysis

Background: The impact of lesion topography (LT), characterised by the Alberta Stroke Programme Early CT Score (ASPECTS), on outcomes after reperfusion therapy in acute ischemic stroke (AIS) is poorly elucidated. We investigated the prognostic accuracy of ASPECTS-based LT assessment and its association with clinical outcomes in AIS patients considered for reperfusion therapy or receiving intravenous thrombolysis (IVT), endovascular thrombectomy (EVT), or none or both. Methods: Studies were identified from PubMed with additional studies added from Google Scholar. The prevalence of individual ASPECTS regions will also be determined. The association of individual ASPECTS regions with the functional outcome at 90 days will be assessed using random-effects modelling for various cut-offs, such as 6, 7 and 8. The association of continuous ASPECTS with the functional outcome at 90 days will also be undertaken. Forest plots of odds ratios (ORs) will be generated. Results: A total of 25 studies have been included in the final analysis, encompassing 11,404 patients. Pooled estimates indicate that the highest prevalence rates were in cases involving the insula and lentiform nucleus. Subgroup analysis for ASPECTS < 6 (OR 6.10; 95% CI 2.50−14.90; p < 0.0001), ASPECTS < 7 (OR 4.58; 95% CI 1.18−17.86; p < 0.0001) and ASPECTS < 8 (OR 2.26; 95% CI 1.32−3.89; p < 0.0001) revealed a significant association with poor functional outcome at 90 days. Decreasing ASPECTS significantly increased the odds of poor functional outcomes at 90 days (SMD −1.15; 95% CI −1.77−−0.52; p < 0.0001). Conclusions: Our meta-analysis demonstrates that decreasing ASPECTS is significantly associated with poor functional outcomes. Individual ASPECTS regions associated with the highest odds of poor functional outcomes were identified. Future studies on the association of LT and clinical outcomes specific to EVT are required.

Association between Early Ischemic Changes and Collaterals in Acute Stroke: A Retrospective Study

BACKGROUND AND PURPOSE

The quality of leptomeningeal collaterals may influence the speed of infarct progression in acute stroke. Our main objective was to evaluate the association of leptomeningeal collateral score and its interaction with time with ischemic changes on CT in patients with acute stroke.

MATERIALS AND METHODS

Adult patients with acute stroke symptoms and anterior circulation large-vessel occlusion on CTA from 2015 to 2019 were included. Routinely performed NCCT and multiphase CTA were reviewed to assess ASPECTS and the leptomeningeal collateral score. We built multivariate regression models to assess the association between leptomeningeal collateral score and its interaction with time and ASPECTS. Performance measures to predict poor ASPECTS at different time thresholds (identified with receiver operating characteristic curve analysis) were estimated in a subgroup of patients with poor leptomeningeal collateral scores.

RESULTS

Leptomeningeal collateral scores 0-1 were associated with lower ASPECTS, and the model with dichotomized and trichotomized leptomeningeal collateral score showed a significant multiplicative interaction between time and the leptomeningeal collateral score. The negative predictive value for poor ASPECTS was >0.9 for at least the first 3 hours from stroke onset to imaging, and the positive predictive value was <0.5 for every time threshold tested in the subgroup of patients with leptomeningeal collateral scores 0-3.

CONCLUSIONS

Poor (0-1) leptomeningeal collateral scores were associated with lower ASPECTS, and an increase in time has a multiplicative interaction with the leptomeningeal collateral score on ASPECTS.

Value of pre-intervention computed tomography perfusion imaging in the assessment of tissue outcome and long-term clinical prognosis in patients with anterior circulation acute ischemic stroke receiving reperfusion therapy: a systematic review

BACKGROUND

Computed tomography perfusion (CTP) imaging has emerged as an important adjunct to the current armamentarium of acute ischemic stroke (AIS) workflow. However, its adoption in routine clinical practice is far from optimal.

PURPOSE

To investigate the putative association of CTP imaging biomarkers in the assessment of prognosis in acute ischemic stroke.

MATERIAL AND METHODS

We performed a systematic review of the literature using MEDLINE, EMBASE, and Cochrane Central Register of Clinical Trials focusing on CTP biomarkers, tissue-based and clinical-based patient outcomes. We included randomized controlled trials, prospective cohort studies, and case-controlled studies published from January 2005 to 28 August 2020. Two independent reviewers conducted the study appraisal, data extraction, and quality assessment of the studies.

RESULTS

A total of 60 full-text studies were included in the final systematic review analysis. Increasing infarct core volume is associated with reduced odds of achieving functional independence (modified Rankin score 0-2) at 90 days and is correlated with the final infarct volume when reperfusion is achieved.

CONCLUSION

CTP has value in assessing tissue perfusion status in the hyperacute stroke setting and the long-term clinical prognosis of patients with AIS receiving reperfusion therapy. However, the prognostic use of CTP requires optimization and further validation.

Clinical Value of Combined Detection of UA and MMP-9 in Evaluating Bleeding Transformation and Prognosis After Thrombolysis in Acute Cerebral Infarction

This paper presents an in-depth study and analysis of the assessment of hemorrhagic transformation and prognostic outcome after thrombolysis in acute cerebral infarction using a combined test and evaluates its clinical value. The ischemic tissue hemodynamic changes were compared and analyzed by the combined application of magnetic resonance conventional examination. Single-factor and multi-factor Logistic regression analysis was applied to the model group samples to determine the independent influencing factors of hemorrhage and to construct a risk prediction model. The Hosmer-Lemeshow chi-square test was used to test the fit of the model, and the area under the ROC curve was used to test the discriminatory ability of the model. The area under the ROC curve was used to test the discriminatory ability of the model. The main purpose of this study was to investigate the clinical diagnostic value of the combined D-D and Hcy and test for the early detection of patients with acute cerebral infarction disease. There was no significant correlation between single PWI-ASPECTS and clinical prognostic MRS score, which may be related to the site and volume of initial diffusion restriction; the percentage of the mismatched area between DWI-PWI and clinical prognostic mRS score was significantly correlated, which helps clinicians to assess the therapeutic effect of non-thrombolytic therapy and provide an important basis for clinical selection of appropriate interventions in the subacute phase of stroke. The sensitivity of D-D, Hcy, and cTnI in the acute cerebral infarction group was 59.4%, 79.6%, and 49.5%, and the specificity was 73.5%, 70.5%, and 91.1%, respectively, with the area under the curve of 0.606, 0.729, and 0.521. The sensitivity, specificity, and area under the curve of the combined assay were higher than those of the single assay. The detection level of high-risk group was the highest, followed by the low-risk group. Pearson correlation analysis suggests that there is a significant correlation between serum UA and MM-9 level and grace score.

Digital subtraction angiography in cerebrovascular disease: current practice and perspectives on diagnosis, acute treatment and prognosis

Digital Subtraction Angiography (DSA) is the gold-standard imaging modality in acute cerebrovascular diagnosis. The role of DSA has become increasingly prominent since the incorporation of endovascular therapy in standards of care for acute ischemic stroke. It is used in the assessment of cerebral vessel patency; however, the therapeutic role of DSA from a prognostic standpoint merits further investigation. The current paper provides an update on current practice on diagnostic, therapeutic and prognostic use of DSA in acute cerebrovascular diseases and various indications and perspectives that may apply, or limit its use, in ongoing surveillance or prognosis. Pre-clinical and clinical studies on the aspects, including but not limited to the morphology of cerebrovasculature in acute ischaemic stroke, are required to delineate and inform its prognostic role.

Role of Neutrophil-Lymphocyte Ratio in the Prognosis of Acute Ischaemic Stroke After Reperfusion Therapy: A Systematic Review and Meta-analysis

Background

Inflammation may mediate response to acute reperfusion therapy (RT) in acute cerebral ischaemia. Neutrophil-lymphocyte ratio (NLR), an inflammatory biomarker, may play an important role in acute ischaemic stroke (AIS) prognostication.

Objective

This meta-analysis sought to examine the effect of NLR on functional outcomes, mortality and adverse outcomes in AIS patients receiving RT.

Methods

Individual studies were retrieved from PubMed/Medline, EMBASE and Cochrane databases. Data were extracted using a standardised data sheet and meta-analysis on association of admission (pre-RT) or delayed (post-RT) NLR with clinical/safety outcomes after RT was conducted.

Results

Thirty-five studies (n = 10 308) were identified for the systematic review with 27 (n = 8537) included in the meta-analyses. Lower admission NLR was associated with good functional outcomes (GFOs), defined as 3-month modified Rankin scale (mRS) 0–2 (SMD = −.46; 95% CI = −.62 to −.29; P < .0001), mRS 0–1 (SMD = −.44; 95% CI = −.66 to −.22; P < .0001) and early neurological improvement (ENI) (SMD = −.55; 95 %CI = −.84 to −.25; P < .0001). Lower delayed admission NLR was also associated with GFOs (SMD = −.80; 95%CI = −.91 to −.68; P < .0001). Higher admission NLR was significantly associated with mortality (SMD = .49; 95%CI = .12 to .85; P = .009), intracerebral haemorrhage (ICH) (SMD = .34; 95% CI = .09 to .59; P = .007), symptomatic ICH (sICH) (SMD = .48; 95% CI = .07 to .90; P = .022) and stroke-associated infection or pneumonia (SMD = .85; 95% CI = .50, 1.19; P < .0001). Higher delayed NLR was significantly associated with sICH (SMD = 1.40; 95% CI = .60 to 2.19; P = .001), ICH (SMD = .94; 95% CI = .41 to 1.46; P < .0001) and mortality (SMD = 1.12; 95% CI = .57 to 1.67; P < .0001). There were variations in outcomes across RT groups.

Conclusion

Higher admission or delayed NLR is significantly associated with worse morbidity, mortality and safety outcomes in AIS patients receiving RT.

Prognostic capacity of hyperdense middle cerebral artery sign in anterior circulation acute ischaemic stroke patients receiving reperfusion therapy: a systematic review and meta-analysis

Pre-intervention CT imaging-based biomarkers, such as hyperdense middle cerebral artery sign (HMCAS) may have a role in acute ischaemic stroke prognostication. However, the clinical utility of HMCAS in settings of reperfusion therapy and the level of prognostic association is still unclear. This systematic review and meta-analysis investigated the association of HMCAS sign with clinical outcomes and its prognostic capacity in acute ischaemic stroke patients treated with reperfusion therapy. Prospective and retrospective studies from the following databases were retrieved from EMBASE, MEDLINE and Cochrane. Association of HMCAS with functional outcome, symptomatic intracerebral haemorrhage (sICH) and mortality were investigated. The random effect model was used to calculate the risk ratio (RR). Subgroup analyses were performed for subgroups of patients receiving thrombolysis (tPA), mechanical thrombectomy (EVT) and/or combined therapy (tPA + EVT). HMCAS significantly increased the rate of poor functional outcome by 1.43-fold in patients (RR 1.43; 95% CI 1.30-1.57; p < 0.0001) without any significant differences in sICH rates (RR 0.91; 95% CI 0.68-1.23; p = 0.546) and mortality (RR 1.34; 95% CI 0.72-2.51; p = 354) in patients with positive HMCAS as compared to negative HMCAS. In subgroup analyses, significant association between HMCAS and 90 days functional outcome was observed in patients receiving tPA (RR 1.53; 95% CI 1.40-1.67; p < 0.0001) or both therapies (RR 1.40; 95% CI 1.08-1.80; p = 0.010). This meta-analysis demonstrated that pre-treatment HMCAS increases risk of poor functional outcomes. However, its prognostic sensitivity and specificity in predicting long-term functional outcome, mortality and sICH after reperfusion therapy is poor.

Clinical outcomes following reperfusion therapy in acute ischemic stroke patients with infective endocarditis: a systematic review

Background

Acute ischemic stroke (AIS) is a common and fatal complication of infective endocarditis (IE); however, there is a lack of understanding regarding treatment efficacy. This systematic review aimed to evaluate the safety and efficacy of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) in IE patients experiencing AIS.

Objectives

The aim of this study was to perform a systematic review investigating the outcomes of AIS in IE patients receiving IVT and/or EVT as a treatment method and to evaluate the safety and efficacy of these methods of reperfusion therapy.

Design

A systematic review in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was conducted.

Data Sources and Methods

The EMBASE, Cochrane, and PubMed databases were searched for literature published between 2005 and 2021 investigating outcomes of reperfusion therapy post-AIS in IE and non-IE patients. Descriptive statistics were used to describe the overall frequency of clinical outcomes, and groupwise comparisons were performed using Fisher’s exact test to assess the significance of groupwise differences.

Results

Three studies were finally included in the systematic review. A total of 13.5% of IE patients compared to 37% of non-IE patients achieved a good functional outcome (modified Rankin Scale score≤ 2) (P < .001). Furthermore, a larger percentage of the IE cohort achieved good functional outcomes after EVT (22.0%) compared to IVT (10.4%) (P = .013). The IE cohort also had a higher 3-month postreperfusion mortality rate (48.8%) compared to the non-IE cohort (24.9%) (P < .001). The rate of intracranial hemorrhage (ICH) postreperfusion was also significantly higher in the IE cohort (23.5%) than in the non-IE cohort (6.5%) (P < .001).

Conclusion

AIS patients with IE, treated with IVT, EVT, or a combination of the two, experience worse clinical and safety outcomes than non-IE patients. EVT yielded better functional outcomes, albeit with higher postreperfusion ICH rates, than IVT.

Leukoaraiosis severity and post-reperfusion outcomes in acute ischaemic stroke: A meta-analysis

OBJECTIVES

Severity of leukoaraiosis may mediate outcomes after reperfusion therapy in acute ischaemic stroke (AIS) patients. However, the level of the association remains poorly understood. We performed a meta-analysis to investigate the impact of leukoaraiosis severity on functional outcome, survival, haemorrhagic complications, and procedural success in AIS patients treated with intravenous thrombolysis and/or endovascular thrombectomy.

MATERIALS AND METHODS

PubMed, EMBASE and the Cochrane library were searched for studies on leukoaraiosis in AIS receiving reperfusion therapy. A random-effects meta-analysis was conducted for post-reperfusion outcomes in AIS patients with absent-to-mild leukoaraiosis and moderate-to-severe leukoaraiosis. The strength of association between moderate-to-severe leukoaraiosis and poor outcomes was quantified using odds ratios (OR).

RESULTS

A total of 15 eligible studies involving 6460 patients (1451 with moderate-to-severe leukoaraiosis and 5009 with absent-to-mild leukoaraiosis) were included in the meta-analysis. Moderate-to-severe leukoaraiosis was significantly associated with poor 90-day functional outcome (OR 3.16; 95% confidence interval (CI) 2.69-3.72; p < .0001), 90-day mortality (OR 3.11; 95% CI 2.27-4.26; p < .0001) and increased risk of symptomatic intracerebral haemorrhage (OR 1.69; 95% CI 1.24-2.32; p = .001) after reperfusion therapy. Overall, no significant association of leukoaraiosis severity with haemorrhagic transformation (HT) and angiographic recanalization status were observed. However, subgroup analysis revealed a significant association of WML severity with HT in patients receiving EVT.

CONCLUSION

Leukoaraiosis is a useful prognostic biomarker in AIS. Patients with moderate-to-severe leukoaraiosis on baseline imaging are likely to have worse clinical and safety outcomes after reperfusion therapy.

Role of diabetes in stroke: Recent advances in pathophysiology and clinical management

The increasing prevalence of diabetes and stroke is a major global public health concern. Specifically, acute stroke patients, with pre-existing diabetes, pose a clinical challenge. It is established that diabetes is associated with a worse prognosis after acute stroke and the various biological factors that mediate poor recovery profiles in diabetic patients is unknown. The level of association and impact of diabetes, in the setting of reperfusion therapy, is yet to be determined. This article presents a comprehensive overview of the current knowledge of the role of diabetes in stroke, therapeutic strategies for primary and secondary prevention of cardiovascular disease and/or stroke in diabetes, and various therapeutic considerations that may apply during pre-stroke, acute, sub-acute and post-stroke stages. The early diagnosis of diabetes as a comorbidity for stroke, as well as tailored post-stroke management of diabetes, is pivotal to our efforts to limit the burden. Increasing awareness and involvement of neurologists in the management of diabetes and other cardiovascular risk factors is desirable towards improving stroke prevention and efficacy of reperfusion therapy in acute stroke patients with diabetes.

Fluid-Attenuated Inversion Recovery Vascular Hyperintensity as a Potential Predictor for the Prognosis of Acute Stroke Patients After Intravenous Thrombolysis

Background

Fluid-attenuated inversion recovery vascular hyperintensity (FVH) can reflect the collateral status, which may be a valuable indicator to predict the functional outcome of acute stroke (AS) patients.

Methods

A total of 190 AS patients with large vessel occlusion (LVO) were retrospectively investigated. All patients completed a 6-month follow-up and their modified Rankin Scale (mRS) scores were recorded at 1, 3, and 6 months after intravenous thrombolysis (IVT). Based on their mRS at 3 months, patients were divided into two groups: poor prognosis (131 patients; 68.9% of all subjects) and favorable prognosis (59 patients; 31.1% of all subjects). The death records of 28 patients were also analyzed in the poor prognosis group.

Results

(1) Univariate and multivariate analyses showed that the higher National Institutes of Health Stroke Scale (NIHSS) score at admission, higher fasting blood glucose, and lower FVH score were independent risk factors to predict the poor prognosis of IVT. (2) Survival analysis indicated that FVH score was the only baseline factor to predict the 6-month survival after IVT. (3) Baseline FVH score had great prediction performance for the prognosis of IVT (area under the curve = 0.853). (4) Baseline FVH score were negatively correlated with the NIHSS score at discharge and mRS score at 1, 3, and 6 months.

Conclusion

Among various baseline clinical factors, only the FVH score might have implications for 3-month outcome and 6-month survival of AS patients after IVT. Baseline FVH score showed great potential to predict the prognosis of the AS patients.

Brain atrophy in acute ischaemic stroke patients treated with reperfusion therapy: a systematic review

BACKGROUND

Brain atrophy (BA) may have a role in acute ischemic stroke (AIS) in mediating outcomes after reperfusion therapy. The extent of this association is not well understood.

PURPOSE

: To examine the impact of pre-existing BA on functional outcome, survival, symptomatic intracerebral hemorrhage (sICH), and early neurological change in patients with AIS treated with intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT).

MATERIAL AND METHODS

PubMed, EMBASE, and the Cochrane library were searched for studies on BA in AIS receiving reperfusion therapy. Studies were included if: (i) patients were aged ≥18 years; (ii) patients had been diagnosed with AIS; (iii) patients received IVT and/or EVT; (iv) studies reported on BA; (v) studies reported on post-reperfusion outcomes; and (vi) studies had a sample size of >25 patients.

RESULTS

A total of 4444 patients from eight studies were included. Four out of seven studies reporting on 90-day functional outcome found pre-existing BA to be significantly associated with poor functional outcome. Moreover, two out of four studies found BA to be a significant predictor of 90-day mortality. None of the included studies reported a significant association of BA with sICH or early neurological deterioration.

CONCLUSION

This systematic review indicates a potential prognostic role of BA in AIS. Quantitative analysis of association of BA with outcomes in AIS is not possible given the heterogeneity in BA assessment and reporting across studies. Future studies using standardized BA assessment are warranted to clarify its association with clinical and safety outcomes in AIS.

Stroke Aetiology and Collateral Status in Acute Ischemic Stroke Patients Receiving Reperfusion Therapy-A Meta-Analysis

BACKGROUND

The interplay between collateral status and stroke aetiology may be crucial in the evaluation and management of acute ischemic stroke (AIS). Our understanding of this relationship and its level of association remains sub-optimal. This study sought to examine the association of pre-intervention collateral status with stroke aetiology, specifically large artery atherosclerosis (LAA) and cardio-embolism (CE), in AIS patients receiving reperfusion therapy, by performing a meta-analysis.

METHODS

Relevant search terms were explored on Medline/PubMed, Embase and Cochrane databases. Studies were included using the following inclusion criteria: (a) patients aged 18 or above; (b) AIS patients; (c) patients receiving reperfusion therapy; (d) total cohort size of >20, and (e) qualitative or quantitative assessment of pre-intervention collateral status on imaging using a grading scale. Random-effects meta-analysis was performed to investigate the association of aetiology with pre-intervention collateral status, and forest plots of risk ratio (RR) were generated.

RESULTS

A meta-analysis was conducted on seven studies, with a cumulative cohort of 1235 patients, to assess the association of pre-intervention collateral status with stroke aetiology. Patients with LAA were associated significantly with an increased rate of good collaterals (RR 1.24; 95% CI 1.04-1.50; p = 0.020, z = 2.33). Contrarily, CE aetiology was associated significantly with a decreased rate of good collaterals (RR 0.83; 95% CI 0.71-0.98; p = 0.027, z = -2.213).

CONCLUSIONS

This study demonstrates that, in AIS patients receiving reperfusion therapy, LAA and CE aetiologies are associated significantly with collateral status.

Cerebral white matter vasculature: still uncharted?

White matter vasculature plays a major role in the pathophysiology of permanent neurological deficits following a stroke or progressive cognitive alteration related to small vessel disease. Thus, knowledge of the complex vascularization and functional aspects of the deep white matter territories is paramount to comprehend clinical manifestations of brain ischemia. This review provides a structured presentation of the existing knowledge of the vascularization of the human cerebral white matter from seminal historical studies to the current literature. First, we revisit the highlights of prenatal development of the endoparenchymal telencephalic vascular system that are crucial for the understanding of vessel organization in the adult. Second, we reveal the tangled history of debates on the existence, clinical significance, and physiological role of leptomeningeal anastomoses. Then, we present how conceptions on white matter vascularization transitioned from the mixed ventriculopetal/ventriculofugal theory, in which a low-flow area was interposed in between concurrent arterial flows, to the purely ventriculopetal theory. The latter model explains variable white matter sensitivity to ischemia by various organizations of ventriculopetal vessel terminals having different origin/length properties and interconnection patterns. Next, arteries supplying primarily the white matter are described according to their length and overall structure. Furthermore, the known distribution territories, to date, are studied in relation to primary anatomical structures of the human cerebral white matter, emphasizing the sparsity of the "ground-truth" data available in the literature. Finally, the implications for both large vessel occlusion and chronic small vessel disease are discussed, as well as the insights from neuroimaging. All things considered, we identify the need for further research on deep white matter vascularization, especially regarding the arterial supply of white matter fiber tracts.

Protection of multiple ischemic organs by controlled reperfusion

Reperfusion injury (RI) is a harmful complication that takes place during recanalization treatment of ischemic organs. Currently, there are no efficacious treatments for protecting the organs against RI. Therefore, it is necessary to discover new strategies to prevent RI. As a novel intervention technique, controlled reperfusion has promising effects on protecting multiple organs from RI, and it is done by adjusting physical parameters of blood flow or chemical compositions of the reperfusion liquid. In this brief review, the status of various controlled reperfusion methods is presented, as well as their application in the protection of ischemic organs.

Acute Ischaemic Stroke in Infective Endocarditis: Pathophysiology and Clinical Outcomes in Patients Treated with Reperfusion Therapy

Infective endocarditis in the setting of acute stroke poses a clinical challenge given the high mortality and morbidity associated with the condition. The pathophysiological mechanisms including clinical and imaging biomarkers that can provide insights into clinical trajectories of such patients are of immense interest. The current paper aims to provide a comprehensive overview of acute stroke with infective endocarditis and provide insights into various clinical factors mediating outcomes and therapeutic strategies, specifically in the setting of reperfusion therapy. Prognostic and therapeutic pathways to potentially improve functional outcomes in these patients are also discussed.

Relationship between estimated glomerular filtration rate and outcome of ischemic stroke patients after mechanical thrombectomy

Aims

We aimed to determine whether preprocedural renal function affects the outcome of acute ischemic stroke (AIS) patients with mechanical thrombectomy (MT) and whether this effect is modified by the onset‐to‐reperfusion time (OTR) and mediated by collateral status.

Methods

Eligible patients with anterior circulation large vessel occlusion (LVO) who underwent MT between August 2018 and August 2020 were reviewed. The main outcome was good functional outcome [defined as modified Rankin Scale (mRS) of 0–2] at 3 months. Multivariable logistic regression analyses were conducted to explore the relationship between renal function and good functional outcome. A moderation analysis and the Johnson‐Neyman technique were performed to assess the interaction between renal function and OTR to predict the outcome of AIS patients with MT.

Results

Among 100 enrolled patients, 36 (36%) exhibited good functional outcome. A decreased preprocedural estimated glomerular filtration rate (pre‐eGFR) was significantly associated with worse functional outcome [adjusted OR, 1.059 (1.012–1.108); p, 0.014], and this effect was partly mediated by collateral circulation. An interaction between OTR and pre‐eGFR on functional outcome was observed (P for interaction, 0.22), and pre‐eGFR only had a significant effect on functional outcome when OTR exceeded 455.8 min. Moreover, the adverse effect of OTR on functional outcome became no longer significant when the pre‐eGFR was higher than 89.0 mL/min/1.73 mL/min/1.73 m².

Conclusions

Renal function was related to functional outcome at 3 months, and this relationship could be modified by OTR. The results suggested that reducing OTR and improving collateral circulation may mitigate the adverse effect of reduced kidney function on functional outcome.

Collateral status reperfusion and outcomes after endovascular therapy: insight from the Endovascular Treatment in Ischemic Stroke (ETIS) Registry

BACKGROUND

Studies have suggested that collateral status modifies the effect of successful reperfusion on functional outcome after endovascular therapy (EVT). We aimed to assess the association between collateral status and EVT outcomes and to investigate whether collateral status modified the effect of successful reperfusion on EVT outcomes.

METHODS

We used data from the ongoing, prospective, multicenter Endovascular Treatment in Ischemic Stroke (ETIS) Registry. Collaterals were graded according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) guidelines. Patients were divided into two groups based on angiographic collateral status: poor (grade 0-2) versus good (grade 3-4) collaterals.

RESULTS

Among 2020 patients included in the study, 959 (47%) had good collaterals. Good collaterals were associated with favorable outcome (90-day modified Rankin Scale (mRS) 0-2) (OR 1.5, 95% CI 1.19 to 1.88). Probability of good outcome decreased with increased time from onset to reperfusion in both good and poor collateral groups. Successful reperfusion was associated with higher odds of favorable outcome in good collaterals (OR 6.01, 95% CI 3.27 to 11.04) and poor collaterals (OR 5.65, 95% CI 3.32 to 9.63) with no significant interaction. Similarly, successful reperfusion was associated with higher odds of excellent outcome (90-day mRS 0-1) and lower odds of mortality in both groups with no significant interaction. The benefit of successful reperfusion decreased with time from onset in both groups, but the curve was steeper in the poor collateral group.

CONCLUSIONS

Collateral status predicted functional outcome after EVT. However, collateral status on the pretreatment angiogram did not decrease the clinical benefit of successful reperfusion.

Diagnostic and prognostic utility of computed tomography perfusion imaging in posterior circulation acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Computed tomography perfusion (CTP) imaging could be useful in the diagnosis of posterior circulation stroke (PCS) and in identifying patients who are likely to experience favorable outcomes following reperfusion therapy. The current study sought to investigate the diagnostic and prognostic capability of CTP in acute ischemic PCS by performing a systematic review and meta-analysis.

METHODS

Medline/PubMed and the Cochrane Library were searched using the terms: "posterior circulation", "CT perfusion", "acute stroke", and "reperfusion therapy". The following studies were included: (1) patients aged 18 years or above; (2) patients diagnosed with PCS; and (3) studies with good methodological design. Pooled sensitivity (SENS), specificity (SPEC), and area under the curve (AUC), computed using the summary receiver operating characteristic (SROC) curves, were used to determine diagnostic/prognostic capability.

RESULTS

Out of 14 studies included, a meta-analysis investigating diagnostic accuracy of CTP was performed on nine studies. Meta-analysis demonstrated comparable diagnostic accuracy of CTP to non-contrast computed tomography (NCCT) (AUC_CTP : 0.90 [95% CI 0.87-0.92] vs. AUC_NCCT : 0.96 [95% CI 0.94-0.97]); however, with higher pooled sensitivity (SENS_CTP : 72% [95% CI 57%-83%] vs. SENS_NCCT : 25% [95% CI 17%-35%]) and lower specificity (SPEC_CTP : 90% [95% CI 83%-94%] vs. SPEC_NCCT : 96% [95% CI 95%-98%]) than NCCT. Meta-analysis to determine prognostic capability of CTP could not be performed.

CONCLUSIONS

CTP has limited diagnostic utility in acute ischemic PCS, albeit with superior diagnostic sensitivity and inferior diagnostic specificity to NCCT. Further prospective trials are required to validate the prognostic capability of CTP-derived parameters in PCS.