MR CLEAN, a multicenter randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands: study protocol for a randomized controlled trial

Clinical perspective in relation to age in patients treated with thrombectomy for anterior circulation stroke in a stroke center in Colombia

Background and aimsEndovascular treatment for cerebrovascular disease is accepted as a first-line option with level I evidence in patients with an early and late time of window of onset symptoms, and an additional option in patients who do not respond or with contraindications to systemic thrombolysis; nevertheless the efficacy and outcomes of some groups were not clear, one of them are patients aged 80 years and older, because they were excluded of the trials, so the evidence is controversial with significant heterogeneity, for that reason in our study, we decided to analyze the age in the patients treated in our stroke center, as a predictor of prognosis, and to provide a baseline for the establishment of personalized treatment plans.MethodsObservational, retrospective study of patients that received endovascular treatment for cerebrovascular disease in a Colombian stroke center between 2016 and 2020, continuous and categorical variables were compared using the Student's t test and Chi-Square. To determine cut-off points in the variable against death and Rankin score variable on 90th day.ResultsIn total, 108 patients were recruited, 35 of them were of 80 or more years, and the mean age was 72.7 years, we found age as a significant variable to predict the risk in the population over 80 years of age [RR 3.37 CI (95% 1.14-103) p  =  0.029].ConclusionsAge younger than 80 is a significant predictor for results and long-term outcomes in patients suffering from stroke, and in patients older than 80 years old a Thrombolysis in Cerebral Infarction score 2b-3 is a predictor of good outcomes. Further studies are needed to evaluate the relationship between intrahospital complications and long-term outcomes.

In Vitro Assessment of Vascular Injury following Stent Retriever Retraction in Clinically Relevant Endothelialized Silicone Models

Mechanical thrombectomy devices have potential to injure the vessel during treatment of acute ischemic stroke. The goal of the current work was to tailor in vitro endothelialized silicone models for stent retriever assessment and to evaluate endothelial injury following treatment by various stent retriever designs and sizes. Clinically relevant neurovascular geometries were first modeled out of silicone, then sterilized, coated with fibronectin, placed in bioreactors, seeded with human endothelial cells, and cultivated under flow. Several sizes of 2 different commercially available stent retrievers were then deployed in, and retracted through, vessels. Vessels were immediately harvested and stained. Endothelial injury, identified as denudation, was quantified by using ImageJ. Results illustrated that endothelial injury ranged from 16%-18% in wire/microcatheter-only treated vessels, 37%-61% in 1-pass treatments, and 52%-70% in 2-pass treatments. Overall, this work showcases an in vitro approach for early stage assessment of the extent and location of vascular injury following stent retriever retraction.

Impact of a stroke care pathway on self-perceived health 3 months after stroke

BACKGROUND

A national stroke care pathway aiming at reducing time delays in stroke care was implemented in Norway in 2018. This study aimed to investigate the impact of goal attainment in the pre- and intrahospital care pathway on self-perceived health 3 months after stroke.

METHODS

Data from the Norwegian Stroke Register (NSR) from 2019 were used. Patients were classified into attainment or non-attainment groups, depending on goal achievement of the SCP. Linear regression analyses were used to assess a possible association between goal attainment and self-perceived health evaluated by EQ-5D-5L and EQ-VAS at 3 months post-stroke.

RESULTS

Among 4,133 included patients, 908 (22%) were included in the attainment group. We found no effect of goal attainment upon mean EQ-5D-5L. However, when adjusting for stroke severity, attaining the SCP was significantly associated with self-perceived health.

CONCLUSION

In this study, with a cohort of patients with mild to moderate strokes, we found no association between attaining goals of the stroke care pathway and self-perceived health. However, stroke severity might have acted as a suppressor variable underscoring the importance of stroke severity for self-perceived health.

[Complications of mechanical thrombectomy]

CLINICAL PROBLEM

Ischemic stroke is the most common cause of disability in adults and an important disease for society; therefore, the prevention, diagnosis, and treatment play an important role. Endovascular mechanical recanalization to reopen large occlusions of the intracerebral vessels has established itself as the gold standard in therapy, which is why knowledge of the most important complications and their management is essential for interventionalists.

PRACTICAL RECOMMENDATIONS

Intracranial hemorrhages, which include intracerebral and subarachnoid hemorrhages, are dreaded complications that significantly worsen the clinical outcome. Early monitoring and optimal management are therefore essential. Cerebral air embolism is a rare but dangerous complication whose prevention is paramount, as treatment options are limited.

Numerical Cincinnati Stroke Scale Versus Stroke Severity Screening Tools for the Prehospital Determination of Large Vessel Occlusion

OBJECTIVES

Previous research demonstrated that the numerical Cincinnati Prehospital Stroke Scale (CPSS) identifies large vessel occlusion (LVO) at similar rates compared to dedicated LVO screening tools. We aimed to compare numerical CPSS to additional stroke scales using a national emergency medical services (EMS) database.

METHODS

Using the ESO Data Collaborative, the largest EMS database with linked hospital data, we retrospectively analyzed prehospital patient records from 2022. Each EMS record was linked to corresponding emergency department (ED) and inpatient records through a data exchange platform. Prehospital CPSS was compared to the Cincinnati Stroke Triage Assessment Tool (C-STAT), the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), and the Balance Eyes Face Arm Speech Time (BE-FAST). The optimal prediction cut points for LVO screening were determined by intersecting the sensitivity and specificity curves for each scale. To compare the discriminative abilities of each scale among those diagnosed with LVO, we used the area under the receiver operating curve (AUROC).

RESULTS

We identified 17,442 prehospital records from 754 EMS agencies with ≥1 documented stroke scale of interest: 30.3% (n = 5,278) had a hospital diagnosis of stroke, of which 71.6% (n = 3,781) were ischemic; of those, 21.6% (n = 817) were diagnosed with LVO. CPSS score ≥2 was found to be predictive of LVO with 76.9% sensitivity, 68.0% specificity, and AUROC 0.787 (95%CI 0.722-0.801). All other tools had similar predictive abilities, with sensitivity/specificity/AUROC of: C-STAT 62.5%/76.5%/0.727 (0.555-0.899); FAST-ED 61.4%/76.1%/0.780 (0.725-0.836); BE-FAST 70.4%/67.1%/0.739 (0.697-0.788).

CONCLUSIONS

The less complex CPSS exhibited comparable performance to three frequently employed LVO detection tools. The EMS leadership, medical directors, and stroke system directors should weigh the complexity of stroke severity instruments and the challenges of ensuring consistent and accurate use when choosing which tool to implement. The straightforward and widely adopted CPSS may improve compliance while maintaining accuracy in LVO detection.

From apoplexy in antiquities to cerebrovascular stroke in modernity: a narrative timeline and tale

Background

Stroke is one of the commonest encountered brain and neurological disorders worldwide. Stroke management has had a major shift in the last 50 years and precisely since the discovery and approval of thrombolysis as an acute management followed by multiple trials on mechanical thrombectomy and its approval. Yet, Stroke is as old as the history of mankind. Historically stroke symptoms’ description is older than the descriptions of the Greco-Roman civilization (500 BC – 800 AD). Before Stroke, the term apoplexy was described in ancient civilizations and evidence of suffering and managing it is preserved within the mummies, inscriptions, and papyri of the Egyptian civilization, clay tablets of the Mesopotamian civilization, medical books of the Chinese civilization, and although physicians and scientists consider the Greco-Roman civilization the base for modern medicine, yet the golden age of Islam (800 – 1200 AD) might have shared more in identifying bases of stroke. The European Renaissance beginning from 1400 AD with its famous anatomists and physicians greatly contributed too to stroke localization and vascular supply.

Conclusions

As medicine and science are in a continuous chain from the past to the future through the present, the current comprehensive review highlights the major important and documented shifts in the history of stroke over more than 4500 years starting from ancient civilizations BC up to 2024 AD.

Machine learning-based diagnostic model for stroke in non-neurological intensive care unit patients with acute neurological manifestations

Stroke is a neurological complication that can occur in patients admitted to the intensive care unit (ICU) for non-neurological conditions, leading to increased mortality and prolonged hospital stays. The incidence of stroke in ICU settings is notably higher compared to the general population, and delays in diagnosis can lead to irreversible neurological damage. Early diagnosis of stroke is critical to protect brain tissue and treat neurological defects. Therefore, we developed a machine learning model to diagnose stroke in patients with acute neurological manifestations in the ICU. We retrospectively collected data on patients' underlying diseases, blood coagulation tests, procedures, and medications before neurological symptom onset from 206 patients at the Chungbuk National University Hospital ICU (July 2020-July 2022) and 45 patients at Chungnam National University Hospital between (July 2020-March 2023). Using the Categorical Boosting (CatBoost) algorithm with Bayesian optimization for hyperparameter selection and k-fold cross-validation to mitigate overfitting, we analyzed model-feature relationships with SHapley Additive exPlanations (SHAP) values. Internal model validation yielded an average accuracy of 0.7560, sensitivity of 0.8959, specificity of 0.7000, and area under the receiver operating characteristic curve (AUROC) of 0.8201. External validation yielded an accuracy of 0.7778, sensitivity of 0.7500, specificity of 0.7931, and an AUROC of 0.7328. These results demonstrated the model's effectiveness in diagnosing stroke in non-neurological ICU patients with acute neurological manifestations using their electronic health records, making it valuable for the early detection of stroke in ICU patients.

Multimodal Machine Learning for Stroke Prognosis and Diagnosis: A Systematic Review

Stroke is a life-threatening medical condition that could lead to mortality or significant sensorimotor deficits. Various machine learning techniques have been successfully used to detect and predict stroke-related outcomes. Considering the diversity in the type of clinical modalities involved during management of patients with stroke, such as medical images, bio-signals, and clinical data, multimodal machine learning has become increasingly popular. Thus, we conducted a systematic literature review to understand the current status of state-of-the-art multimodal machine learning methods for stroke prognosis and diagnosis. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines during literature search and selection, our results show that the most dominant techniques are related to the fusion paradigm, specifically early, joint and late fusion. We discuss opportunities to leverage other multimodal learning paradigms, such as multimodal translation and alignment, which are generally less explored. We also discuss the scale of datasets and types of modalities used to develop existing models, highlighting opportunities for the creation of more diverse multimodal datasets. Finally, we present ongoing challenges and provide a set of recommendations to drive the next generation of multimodal learning methods for improved prognosis and diagnosis of patients with stroke.

Trial selection criteria should not be used for clinical decisions and recommendations: the thrombectomy trials example

BACKGROUND

Despite multiple calls for more inclusive studies, most clinical trial eligibility criteria remain too restrictive. Thrombectomy trials have been no exception.

METHODS

We review the landmark trials that have shown the benefits of thrombectomy, their eligibility criteria, and consequences on clinical practice. We discuss the rationale behind various reasons for exclusions. We also examine the logical problem involved in using eligibility criteria as indications for treatment.

RESULTS

Most thrombectomy trials have been too restrictive. This has been shown by a plethora of follow-up studies that have refuted most of the previously recommended trial eligibility restrictions. Meanwhile, the effect of clinical recommendations based on restrictive eligibility criteria is that treatment has been denied to the majority of patients who could have benefitted. Trial eligibility criteria cannot be used to make clinical decisions or recommendations unless, like any other medical diagnosis, they have been shown capable of reliably differentiating patients into those that will, and those that will not benefit from treatment. This goal can only be achieved with all-inclusive pragmatic trials.

CONCLUSION

Restrictive eligibility criteria render clinical trials incapable of guiding medical decisions or recommendations.

Association of Narrow Anterior Communicating Artery or Contralateral A1 Segment with Poor Outcomes After Mechanical Thrombectomy

Background and Objectives: Contralateral A1 and AComA aplasia/hypoplasia are critically important in distal ICA T occlusion as the protective collateral blood supply from the circle of Willis via the anterior communicating artery is compromised. Although the terms aplasia/hypoplasia are used broadly in the literature, the need for concrete measurements and data on their clinical significance is apparent. Features of the individual anatomy of the circle of Willis may determine patient outcomes. We aim to determine the cut-off values of contralateral A1 and AComA segments that determine worse outcomes for patients with acute ischemic stroke with T occlusion of the terminal internal carotid artery. Material and Methods: Retrospective patient data from 2015 to 2020 and prospective data from 2021 to 2022 of 482 patients with diagnosed acute ischemic stroke that underwent mechanical thrombectomy at the Republican Vilnius University Hospital (Vilnius, Lithuania) were obtained. Of these patients, 70 were selected with occlusion of internal carotid artery bifurcation and extension to M1 or A1 segments. For statistically significant interactions, patient data were analyzed using two statistical methods (logistic regression and Multivariate Adaptive Regression Splines (MARS)). Results: The narrowest segment of contralateral A1 and/or AComA was statistically significant for 7-day NIHSS, and the optimal cut-off points for this variable were 1.1 mm (MARS model) and 1.2 mm (logistic regression, p = 0.0079, sensitivity 66.7%, specificity 67.9%). The other considered variables (age, gender, time from last seen well to groin puncture, intravenous recombinant tissue plasminogen activator, admission NIHSS, and ASPECT score) and their interactions were not statistically significant. Conclusions: A negative correlation was found between the narrowest segment and seven days of NIHSS. A larger diameter of contralateral A1 and AComA appears to be essential for better patient outcomes at 7-day evaluation post mechanical thrombectomy.

Timeliness and accuracy of the 7-Item Japan Urgent Stroke Triage (JUST-7) score, a prehospital stroke triage tool, assessed by emergency medical services

The prompt initiation of stroke treatment significantly influences patient outcomes, highlighting the crucial role of prehospital triage. This study aimed to assess the implementation of the 7-Item Japan Urgent Stroke Triage (JUST-7) score by emergency medical services (EMS) in our region and its effect on emergency transportation for suspected stroke patients. Data were collected from patients suspected of having an acute stroke with a Cincinnati Prehospital Stroke Scale (CPSS) score of 1 or more who were transferred by ambulance within 24 h of symptom onset. Two prehospital stroke scales were employed during different periods: period 1 with CPSS alone (January to December 2020) and period 2 with both CPSS and JUST-7 (January 2021 to March 2023). On-scene time data were obtained from the EMS crews, and data regarding the final diagnosis of patients and their outcomes were obtained from the respective hospitals to which the patients were transferred. These data were compared between periods 1 and 2 and between the CPSS and JUST-7. The results revealed that additional evaluation with JUST-7 did not affect ambulance transport time. The CPSS+JUST-7 approach demonstrated higher specificity in identifying stroke and major artery occlusion than with the CPSS alone; however, an appropriate cut-off value needs to be considered. The JUST-7 achieved a diagnostic concordance rate of 35.9% for the most likely stroke type and 64.0% for the first two most likely types. This research emphasizes the potential of JUST-7 as a valuable addition to prehospital stroke diagnosis protocols. Its flexibility in adapting cut-off values based on regional factors and available medical resources optimizes its utility in diverse healthcare settings. The JUST-7 score is a promising tool for improving patient outcomes through prompt and accurate prehospital assessments.

Differences in stroke clinical presentation among sexes

INTRODUCTION

There are sex-based differences in stroke epidemiology, treatment, and outcomes. In this manuscript, we discuss the differences that exist in the clinical presentation of acute stroke among sexes.

DISCUSSION

We present the differences in stroke presentation among sexes including age at the time of presentation, severity of stroke on presentation, and stroke type and location. We discuss the atypical clinical presentations, explore the radiographic findings on presentation (including location, infarct core volume, the impact of collateral circulation, hematoma location in intracranial hemorrhage), and discuss differences in time elapsed between symptom onset and management amongst sexes.

CONCLUSION

Differences exist in stroke clinical presentation amongst sexes. These disparities have public health implications, and as they become better understood, impact awareness campaigns in both the public and healthcare communities.

Validation of the transcranial Doppler rescue criteria for mechanical thrombectomy

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) identifies acute stroke patients with arterial occlusion where treatment may not effectively open the blocked vessel. This study aimed to examine the clinical utility and prognostic value of TCD flow findings in patients enrolled in a multicenter prospective study (CLOTBUST-PRO).

METHODS

Patients enrolled with intracranial occlusion on computed tomography angiography (CTA) who underwent urgent TCD evaluation before intravenous thrombolysis was included in this analysis. TCD findings were assessed using the mean flow velocity (MFV) ratio, comparing the reciprocal ratios of the middle cerebral artery (MCA) depths bilaterally (affected MCA-to-contralateral MCA MFV [aMCA/cMCA MFV ratio]).

RESULTS

A total of 222 patients with intracranial occlusion on CTA were included in the study (mean age: 64 ± 14 years, 62% men). Eighty-eight patients had M1 MCA occlusions; baseline mean National Institutes of Health Stroke Scale (NIHSS) score was 16, and a 24-hour mean NIHSS score was 10 points. An aMCA/cMCA MFV ratio of <.6 had a sensitivity of 99%, specificity of 16%, positive predictive value (PV) of 60%, and negative PV of 94% for identifying large vessel occlusion (LVO) including M1 MCA, terminal internal carotid artery, or tandem ICA/MCA. Thrombolysis in Brain Ischemia scale, with (grade ≥1) compared to without flow (grade 0), showed a sensitivity of 17.1%, specificity of 86.9%, positive PV of 62%, and negative PV of 46% for identifying LVO.

CONCLUSIONS

TCD is a valuable modality for evaluating arterial circulation in acute ischemic stroke patients, demonstrating significant potential as a screening tool for intravenous/intra-arterial lysis protocols.

Ischemic Stroke in the Cardiac Surgery Intensive Care Unit: A Quality Improvement Study

OBJECTIVE

To investigate the frequency of stroke and code stroke activation and the factors influencing code stroke management in postoperative cardiac surgical patients.

DESIGN

A retrospective quality improvement study was conducted between January 1, 2016, and December 31, 2021.

SETTING

The Cardiac Surgery Recovery Unit (CSRU) at London Health Sciences Centre in London, Ontario, Canada.

PARTICIPANTS

Postcardiac surgery patients aged 18 years or older who developed ischemic stroke during their admission to the CSRU.

INTERVENTIONS

No specific interventions were administered as part of this study. Code stroke activation mobilizes a specialized team. The objectives include assessment by a physician within 10 minutes, obtaining neuroimaging and interpretation within 45 minutes, and beginning treatment within 60 minutes.

MEASUREMENTS AND MAIN RESULTS

The incidence rate of stroke in the CSRU was 1.3%, and 34% of these patients had code stroke activated. The time since the last known well status was 11 ± 8 hours. The most common reasons for not activating code stroke were not meeting both timing and clinical criteria. The average time for computed tomography (CT) scan was 36 ± 22 minutes. Among patients who had code stroke activated, 24% had large- vessel occlusion (LVO), and 67% of those with LVO had an established stroke on their initial CT.

CONCLUSION

Code stroke was activated in only one-third of patients who experienced a stroke following cardiac surgery. Additionally, out of those who had code stroke activated, only one-fourth were diagnosed with LVO. Among those with LVO, two-thirds were found to have a well-established stroke on noncontrast CT scans and were deemed ineligible for intervention.

Ion Dyshomeostasis in the Early Hyperacute Phase after a Temporary Large-Vessel Occlusion Stroke

Element dysregulation is a pathophysiologic hallmark of ischemic stroke. Prior characterization of post-stroke element dysregulation in the photothrombotic model demonstrated significant element changes for ions that are essential for the function of the neurovascular unit. To characterize the dynamic changes during the early hyperacute phase (<6 h), we employed a temporary large-vessel occlusion stroke model. The middle cerebral artery was temporarily occluded for 30 min in male C57BL/6 mice, and coronal brain sections were prepared for histology and X-ray fluorescence microscopy from 5 to 120 min post-reperfusion. Ion dysregulation was already apparent by 5 min post-reperfusion, evidenced by reduced total potassium in the lesion. Later time points showed further dysregulation of phosphorus, calcium, copper, and zinc. By 60 min post-reperfusion, the central portion of the lesion showed pronounced element dysregulation and could be differentiated from a surrounding region of moderate dysregulation. Despite reperfusion, the lesion continued to expand dynamically with increasing severity of element dysregulation throughout the time course. Given that the earliest time point investigated already demonstrated signs of ion disruption, we anticipate such changes may be detectable even earlier. The profound ion dysregulation at the tissue level after reperfusion may contribute to hindering treatments aimed at functional recovery of the neurovascular unit.

Tenecteplase versus Alteplase before thrombectomy: A comprehensive evaluation of clinical and angiographic impact: Insights from the ETIS registry

INTRODUCTION

Data on prior use of Tenecteplase versus Alteplase in acute stroke management by mechanical thrombectomy are controversial. Our primary objective was to make a comprehensive comparative assessment of clinical and angiographic efficacy and safety outcomes in a large prospective observational study.

METHODS

We included stroke patients who were eligible for intravenous thrombolysis and endovascular thrombectomy between 2019 and 2021, from an ongoing registry in twenty comprehensive stroke centers in France. We divided patients into two groups based on the thrombolytic agent used (Alteplase vs Tenecteplase). We then compared their treatment times, and their angiographic (TICI scale), clinical (mRS at three months and sICH) and safety outcomes after controlling for potential confounders using propensity score methods.

RESULTS

We evaluated 1131 patients having undergone thrombectomy for the final analysis, 250 received Tenecteplase and 881 Alteplase. Both groups were of the same median age (75 vs 74 respectively), and had the same baseline NIHSS score (16) and ASPECTS (8). There was no significant difference for First Pass Effect (OR 0.93, 95 % CI 0.76-1.14, p = 0.75), time required for reperfusion (OR 0.03, 95 % CI 0.09-0.16, p = 0.49), or for final reperfusion status. Clinically, functional independence at 90 days was similar in both groups (OR 0.82, 95 % CI 0.61-1.10, p = 0.18) with the same risk of sICH (OR 1.36, 95 % CI 0.77-2.41, p = 0.28). However, Tenecteplase patients had shorter imaging-to-groin puncture times (99 vs 142 min, p < 0.05).

CONCLUSIONS

Tenecteplase showed no better clinical or angiographic impact on thrombectomy compared to Alteplase. Nevertheless, it appeared associated with a shorter thrombolysis-to-groin puncture time.

Whole Blood Viscosity and Cerebral Blood Flow in Acute Ischemic Stroke

Existing effective treatments for ischemic stroke restore blood supply to the ischemic region using thrombolysis or mechanical removal of clot. However, it is increasingly recognized that successful removal of occlusive thrombus from the large artery-recanalization, may not always be accompanied by successful restoration of blood flow to the downstream tissues-reperfusion. Ultimately, brain tissue survival depends on cerebral perfusion, and a functioning microcirculation. Because capillary diameter is often equal to or smaller than an erythrocyte, microcirculation is largely dependent on erythrocyte rheological (hemorheological) factors such as whole blood viscosity (WBV). Several studies in the past have demonstrated elevated WBV in stroke compared with healthy controls. Also, elevated WBV has shown to be an independent risk factor for stroke. Elevated WBV leads to endothelial dysfunction, decreases nitric oxide-dependent flow-mediated vasodilation, and promotes hemostatic alterations/thrombosis, all leading to microcirculation sludging. Compromised microcirculation further leads to decreased cerebral perfusion. Hence, modulating WBV through pharmacological agents might be beneficial to improve cerebral perfusion in stroke. This review discusses the effect of elevated WBV on endothelial function, hemostatic alterations, and thrombosis leading to reduced cerebral perfusion in stroke.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Numerical Cincinnati Stroke Scale versus Stroke Severity Screening Tools for the Prehospital Determination of LVO

Background

Previous research demonstrated that the numerical Cincinnati Prehospital Stroke Scale (CPSS) identifies large vessel occlusion (LVO) at similar rates compared to a limited number of stroke severity screening tools. We aimed to compare numerical CPSS to additional stroke scales using a national EMS database.

Methods

Using the ESO Data Collaborative, the largest EMS database with hospital linked data, we retrospectively analyzed prehospital patient records for the year 2022. Stroke and LVO diagnoses were determined by ICD-10 codes from linked hospital discharge and emergency department records. Prehospital CPSS was compared to the Cincinnati Stroke Triage Assessment Tool (C-STAT), the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), and the Balance Eyes Face Arm Speech Time (BE-FAST). The optimal prediction cut-points for LVO screening were determined by intersecting the sensitivity and specificity curves for each scale. To compare the discriminative abilities of each scale among those diagnosed with LVO, we used the area under the receiver operating curve (AUROC).

Results

We identified 17,442 prehospital records from 754 EMS agencies with ≥ 1 documented stroke scale of interest: 30.3% (n=5,278) had a hospital diagnosis of stroke, of which 71.6% (n=3,781) were ischemic; of those, 21.6% (n=817) were diagnosed with LVO. CPSS score ≥ 2 was found to be predictive of LVO with 76.9% sensitivity, 68.0% specificity, and AUROC 0.787 (95% CI 0.722-0.801). All other tools had similar predictive abilities, with sensitivity / specificity / AUROC of: C-STAT 62.5% / 76.5% / 0.727 (0.555-0.899); FAST-ED 61.4% / 76.1%/ 0.780 (0.725-0.836); BE-FAST 70.4% / 67.1% / 0.739 (0.697-0.788).

Conclusion

The less complex CPSS exhibited comparable performance to three frequently employed LVO detection tools. EMS agency leadership, medical directors, stroke system directors, and other stroke leaders may consider the complexity of stroke severity instruments and challenges with ensuring accurate recall and consistent application when selecting which instrument to implement. Use of the simpler CPSS may enhance compliance with the utilization of LVO screening instruments while maintaining the accuracy of prehospital LVO determination.

Advancements in diagnostic and interventional radiology for stroke treatment: the path from trial to bedside through the pre-MR CLEAN, MR CLEAN, and MR CLEAN II eras

The stroke field is inevitably connected with imaging in which radiologists fulfill a central role. Our landmark MR CLEAN trial led to the implementation of baseline computed tomography angiography or magnetic resonance angiography in the acute stroke workup and subsequent endovascular treatment (EVT) for ischemic stroke patients with a large vessel occlusion in the anterior circulation, resulting in numerous patients worldwide currently being treated often successfully. A reversal of the pathophysiologic process behind an acute cerebrovascular event was made possible. Subsequently, in the MR CLEAN II trials, the clinical impact of both diagnostic and interventional radiologists remained a cornerstone of our research, which means value-based radiology. Within these MR CLEAN II trials, we proved that aspirin and heparin during EVT should be avoided due to increased symptomatic intracranial hemorrhage risk (MR CLEAN-MED). We concluded there is additional benefit of EVT in the 6-to-24-h window after stroke in the presence of good collaterals on baseline CTA (MR CLEAN-LATE). The impactful success of our stroke trials that changed many guidelines was mainly attributable to (1) the societal burden of the disease, with two thirds of patients dying or being independent at 3 months; (2) the fact that stroke is a common disease, (3) the relatively simple and pragmatic approach of the trials resembling real-world setting; (4) the acceleration of implementation in clinical practice facilitated by a structured approach to guideline development and conditional funding; and foremost (5) the excellent collaboration on a professional level between-disciplines, i.e., diagnostic radiologists, interventionalists, and neurologists.Critical relevance statement The MR CLEAN and MR CLEAN II trials have had tremendous impact on clinical practice, directly by more patients being treated with an effective intervention and indirectly through adoption of evidence-based guidelines. It is in this setting of stroke treatment that diagnostic and interventional radiologists have played a crucial role and created clinical impact.

Mechanical thrombectomy for AIS from large vessel occlusion - current trends and future perspectives

Stroke is found to be one of the global top causes of mortality and the major factor in years of life with a handicap (DALYs). Ischemic strokes contributed to nearly 70% of all strokes worldwide. For endovascular thrombectomy in acute ischemic stroke with large vessel obstruction (AIS-LVO), using stent retrievers and/or reperfusion catheters has become the gold standard of therapy. The methodology involved keyword-based search in databases like PubMed, Embase, and Google Scholar for recent publications on mechanical thrombectomy (MT), AIS, large vessel occlusion (Large Vessel Occlusion (LVO)), screening relevant articles, retrieving full texts, and synthesizing key findings on procedural advancements, patient selection, COVID-19 (coronavirus disease 2019) impact, delay effects, effectiveness, clinical outcomes, and future perspectives. Only people with substantial cerebral artery obstruction may do well from MT. This includes the distal carotid artery and the proximal middle cerebral artery (segment M1). The size of a blocked vessel and NIHSS (National Institute of Health Stroke Scale) score are directly connected. Both the 2018 and 2019 versions of the AHA/ASA (American Heart Association/American Stroke Association) Guidelines for the Early Management of Patients with Acute Ischemic Stroke contained the recommendations that cases with AIS-LVO get endovascular therapy when administered during the time frame of 0-6 h after onset (Grade IA evidence). It is questionable whether this group of patients can be managed without the need for intravenous tissue plasminogen activator at the onset. When functional independence [modified Rankin Scale (mRS) score 2] was present at long-term follow-up, the endovascular intervention was favored. Tenecteplase, which differs from alteplase in terms of genetic variation, has a greater half-life and a higher level of fibrin selectivity, enabling bolus infusion. Studies have also demonstrated its efficacy and safety, as well as its long-term cost-effectiveness.

MRI-based parameter inference for cerebral perfusion modelling in health and ischaemic stroke

Cerebral perfusion modelling is a promising tool to predict the impact of acute ischaemic stroke treatments on the spatial distribution of cerebral blood flow (CBF) in the human brain. To estimate treatment efficacy based on CBF, perfusion simulations need to become suitable for group-level investigations and thus account for physiological variability between individuals. However, computational perfusion modelling to date has been restricted to a few patient-specific cases. This study set out to establish automated parameter inference for perfusion modelling based on neuroimaging data and thus enable CBF simulations of groups. Magnetic resonance imaging (MRI) data from 75 healthy senior adults were utilised. Brain geometries were computed from healthy reference subjects' T1-weighted MRI. Haemodynamic model parameters were determined from spatial CBF maps measured by arterial spin labelling (ASL) perfusion MRI. Thereafter, perfusion simulations were conducted in 75 healthy cases followed by 150 acute ischaemic stroke cases representing an occlusion and CBF cessation in the left and right middle cerebral arteries. The anatomical fitness of the brain geometries was evaluated by comparing the simulated grey (GM) and white matter (WM) volumes to measurements in healthy reference subjects. Strong positive correlations were found in both tissue types (GM: Pearson's r 0.74, P<0.001; WM: Pearson's r 0.84, P<0.001). Haemodynamic parameter tuning was verified by comparing the total volumetric blood flow rate to the brain in healthy reference subjects and simulations (Pearson's r 0.89, P<0.001). In acute ischaemic stroke cases, the simulated infarct volume using a perfusion-based estimate was 197±25 ml. Computational predictions were in agreement with anatomical and haemodynamic values from the literature concerning T1-weighted, T2-weighted, and phase-contrast MRI measurements in healthy scenarios and acute ischaemic stroke cases. The acute stroke simulations did not capture small infarcts (left tail of the distribution), which could be explained by neglected compensatory mechanisms, e.g. collaterals. The proposed parameter inference method provides a foundation for group-level CBF simulations and for in silico clinical stroke trials which could assist in medical device and drug development.

Reducing Door-In to Door-Out Time for Patients Receiving a Mechanical Thrombectomy Using AutoLaunch Protocol

Background

Door-in to door-out (DIDO) time for large vessel occlusion (LVO) stroke is an emerging stroke performance measure. Initial presentation at a non-Comprehensive Stroke Center (CSC) requires a transfer process that minimizes delays. Our objective was to assess whether DIDO time for stroke patients was reduced after implementation of an AutoLaunch protocol for interfacility transfers.

Methods

This was a pre-post analysis of an AutoLaunch protocol for all acute stroke patients transferred to a CSC for mechanical thrombectomy. The distribution of DIDO times between patients transferred via the AutoLaunch and traditional dispatch protocols were compared.

Results

We evaluated 92 interfacility transfers, with 22 utilizing the AutoLaunch protocol and 70 utilizing traditional dispatch. Among AutoLaunch transfers, the median DIDO time was 85 minutes (IQR: 71, 133), while the median DIDO time among the traditional transfers was 109 minutes (IQR, 84, 144) (p=0.044).

Conclusion

Implementation of an AutoLaunch protocol for patients with suspected LVO was associated with a reduction in DIDO time to CSCs. Further studies should evaluate patient outcomes based on transfer strategies.

(VISIION-S): Viz.ai Implementation of Stroke augmented Intelligence and communications platform to improve Indicators and Outcomes for a comprehensive stroke center and Network - Sustainability

OBJECTIVES

As Comprehensive Stroke Centers (CSCs) strive to improve neuro-intervention (NIR) times, process improvements are put in place to streamline workflows. Our prior publication (VISIION) demonstrated improvements in key performance indicators (KPIs). The purpose VISIION-S was to analyze whether those results were sustainable.

MATERIALS AND METHODS

Consecutive Direct Arriving LVO (DALVO) and telemedicine transfer LVO (BEMI) stroke NIR cases were assessed, including subgroups of DALVO-OnHours, DALVO-OffHours, BEMI-OnHours, and BEMI-OffHours. We analyzed times for the original 6 months pre (6/10/20-1/15/21) and compared them to a 17 month post-implementation period (1/16/21- 6/25/22) to evaluate for sustainability. Mann-Whitney U was utilized.

RESULTS

150 NIR cases were analyzed pre (n = 47) v. post (n = 103) implementation (DALVO-OnHours 7 v. 20, DALVO-OffHours 10 v. 25, BEMI-OnHours 13 v. 20, BEMI-OffHours 17 v. 38). For Door-to-groin (DTG), improvement was noted for DALVO-OffHours 39%(157 min,96 min;p < 0.001), DALVO-ALL 25%(127 min,95 min;p = 0.006), BEMI-OffHours 46%(45 min,25 min;p = 0.023), and BEMI-ALL 40%(42 min,25 min;p = 0.005). Activation-to-groin (ATG), door-to-device (DTD), and door-to-recanalization (DTR) also showed statistical improvements. For DALVO-OffHours, there were reductions in door to CT (DTC) 80%(26 min,5 min;p < 0.001), ATG 32%(90 min,61 min;p = 0.036), DTG 39%(157 min,96 min;p < 0.001), DTD 31%(178 min,123 min;p = 0.002), and DTR 32%(197 min,135 min;p = 0.003).

CONCLUSIONS

We noted sustainability over a 17 month period with sustained reduction in KPIs for even more NIR time interval comparisons. In the greatest opportunity subgroup (DALVO-OffHours), we noted a reduction in all 5 time interval metrics. Our sustainability finding is important to show that process improvements continued even after the immediate period, adding credibility to the results. Models such as this could be useful for other centers striving to optimize workflow and improve times.

Reperfusion Therapies in Acute Ischemic Stroke Beyond the Conventional Time Window: A Narrative Review

Stroke is the second most common cause of death worldwide, with 50% of survivors experiencing long-term disability. For more than two decades, treatment with intravenous thrombolysis (IVT) and mechanical endovascular thrombectomy (MET), the only approved stroke reperfusion therapies, was restricted to patients within the 4.5-6 hour time window, respectively. Therefore, patients who presented with acute ischemic stroke (AIS) beyond the conventional time window were excluded from reperfusion treatment. This narrative review aims to review the scientific literature on the possibilities of reperfusion therapies for patients who present with an unknown time of stroke onset, and those with stroke onset beyond the conventional 4.5-6 hour time window. Beyond the conventional time window, the eligibility of patients for IVT or MET, the two main therapeutic procedures, is decided based on the concept of penumbral imaging. Penumbral imaging identifies patients with hypoperfused but viable brain tissue, who could benefit from reperfusion. On the other hand, clock-based DWI-fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can detect stroke that has occurred within 4.5 hours in patients with an unknown time of onset, including patients who awaken with stroke. The introduction of penumbral imaging and MRI-based tissue clocking as imaging biomarkers for stroke has revolutionized stroke therapy, potentially allowing for personalized treatment of eligible stroke patients.

The essential role of neuroimaging in diagnosing and managing cerebrovascular disease in Africa: a review

BACKGROUND

Cerebrovascular disease is a significant cause of morbidity and mortality in Africa, and using neuroimaging techniques has improved the diagnosis and management of this disease. However, there is a lack of comprehensive reviews of the role and effectiveness of neuroimaging techniques in the African context.

METHODS

We reviewed the literature to evaluate the role of neuroimaging in diagnosing and managing cerebrovascular disease in Africa. Our search included electronic databases such as PubMed, Scopus, and Google Scholar from 2000 to April 2023. We included peer-reviewed studies written in English that reported on the use of neuroimaging in diagnosing and managing cerebrovascular disease in African populations. We excluded non-peer-reviewed articles, letters, editorials, and studies unrelated to cerebrovascular disease, neuroimaging, or Africa. A total of 102 potential articles were identified; after applying our exclusion criteria and removing duplicated articles, 51 articles were reviewed.

RESULTS

Our findings suggest that neuroimaging techniques such as CT, MRI, and Skull x-ray play a crucial role in diagnosing and managing cerebrovascular disease in Africa. CT and MRI were the most commonly used techniques, with CT being more widely available and less expensive than MRI. However, challenges to using neuroimaging in Africa include the high cost of equipment and maintenance, lack of trained personnel, and inadequate infrastructure. These challenges limit the widespread use of neuroimaging in diagnosing and managing cerebrovascular disease in Africa.

CONCLUSION

Neuroimaging techniques are essential for diagnosing and managing cerebrovascular disease in Africa, but challenges to their use must be addressed to improve healthcare outcomes. Our policy recommendations can help improve the availability and accessibility of neuroimaging services in Africa.

A simplified mesoscale 3D model for characterizing fibrinolysis under flow conditions

One of the routine clinical treatments to eliminate ischemic stroke thrombi is injecting a biochemical product into the patient's bloodstream, which breaks down the thrombi's fibrin fibers: intravenous or intravascular thrombolysis. However, this procedure is not without risk for the patient; the worst circumstances can cause a brain hemorrhage or embolism that can be fatal. Improvement in patient management drastically reduced these risks, and patients who benefited from thrombolysis soon after the onset of the stroke have a significantly better 3-month prognosis, but treatment success is highly variable. The causes of this variability remain unclear, and it is likely that some fundamental aspects still require thorough investigations. For that reason, we conducted in vitro flow-driven fibrinolysis experiments to study pure fibrin thrombi breakdown in controlled conditions and observed that the lysis front evolved non-linearly in time. To understand these results, we developed an analytical 1D lysis model in which the thrombus is considered a porous medium. The lytic cascade is reduced to a second-order reaction involving fibrin and a surrogate pro-fibrinolytic agent. The model was able to reproduce the observed lysis evolution under the assumptions of constant fluid velocity and lysis occurring only at the front. For adding complexity, such as clot heterogeneity or complex flow conditions, we propose a 3-dimensional mesoscopic numerical model of blood flow and fibrinolysis, which validates the analytical model's results. Such a numerical model could help us better understand the spatial evolution of the thrombi breakdown, extract the most relevant physiological parameters to lysis efficiency, and possibly explain the failure of the clinical treatment. These findings suggest that even though real-world fibrinolysis is a complex biological process, a simplified model can recover the main features of lysis evolution.

Predicting Mechanical Thrombectomy Outcome and Time Limit through ADC Value Analysis: A Comprehensive Clinical and Simulation Study Using Machine Learning

Predicting outcomes after mechanical thrombectomy (MT) remains challenging for patients with acute ischemic stroke (AIS). This study aimed to explore the usefulness of machine learning (ML) methods using detailed apparent diffusion coefficient (ADC) analysis to predict patient outcomes and simulate the time limit for MT in AIS. A total of 75 consecutive patients with AIS with complete reperfusion in MT were included; 20% were separated to test data. The threshold ranged from 620 × 10^-6 mm²/s to 480 × 10^-6 mm²/s with a 20 × 10^-6 mm²/s step. The mean, standard deviation, and pixel number of the region of interest were obtained according to the threshold. Simulation data were created by mean measurement value of patients with a modified Rankin score of 3-4. The time limit was simulated from the cross point of the prediction score according to the time to perform reperfusion from imaging. The extra tree classifier accurately predicted the outcome (AUC: 0.833. Accuracy: 0.933). In simulation data, the prediction score to obtain a good outcome decreased according to increasing time to reperfusion, and the time limit was longer among younger patients. ML methods using detailed ADC analysis accurately predicted patient outcomes in AIS and simulated tolerance time for MT.

Neurointerventional Radiology: History, Present and Future

Neurointerventional Radiology (NIR), encompassing neuroendovascular surgery, endovascular neurosurgery, and interventional neurology, is an innovative and rapidly evolving multidisciplinary specialty focused on minimally invasive therapies for a wide range of neurological disorders. This review provides a comprehensive overview of NIR, discussing the three routes into the field, highlighting their distinct training paradigms, and emphasizing the importance of unified approaches through organizations like the Society of Neurointerventional Surgery (SNIS). The paper explores the benefits of co-managed care and its potential to improve patient outcomes, as well as the role of interdisciplinary collaboration and cross-disciplinary integration in advancing the field. We discuss the various contributions of neurosurgery, radiology, and neurology to cerebrovascular surgery, aiming to inform and educate those interested in pursuing a career in neurointervention. Additionally, the review examines the adoption of innovative technologies such as robotic-assisted techniques and artificial intelligence in NIR, and their implications for patient care and the future of the specialty. By presenting a comprehensive analysis of the field of neurointervention, we hope to inspire those considering a career in this exciting and rapidly advancing specialty, and underscore the importance of interdisciplinary collaboration in shaping its future.

Budget impact of endovascular treatment for acute ischaemic stroke patients in the Netherlands for 2015-2021

INTRODUCTION

Endovascular treatment (EVT) has been proven to be both effective and cost-effective for patients with acute ischaemic stroke. We investigated the budget impact of large-scale implementation of EVT for acute ischaemic stroke patients in the Netherlands for 2015-2021.

METHODS

An analysis was performed from a healthcare perspective as a preplanned substudy of the Multicenter Randomized Clinical trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN). Estimated yearly costs during follow-up after stroke for patients who had or had not been treated with EVT as add-on to usual care were linked to numbers of new patients retrieved from 2 Dutch registries of EVT that started after the last inclusion in MR CLEAN (2014). Aggregated costs and costs per care sector were calculated based on prevalence using a population dynamic tool.

RESULTS

From 2015, the yearly number of new acute ischaemic stroke patients receiving EVT increased almost threefold, from 812 in 2015 to 2,370 in 2021. The introduction of EVT plus usual care resulted in estimated net annual savings that increased from € 2.9 million in 2015 to € 58 million in 2021.

CONCLUSION

Offering EVT as add-on to usual care for acute ischaemic stroke patients was increasingly cost saving from a national healthcare perspective but affected distinct healthcare sectors differently.

Too bad to treat? Predicting clinical outcome after mechanical thrombectomy in octogenarians

OBJECTIVES

We aimed to reveal the effect of the totaled health risk in vascular events (THRIVE) score and the radiological parameters of the Alberta stroke program early computed tomography score (ASPECTS), the Van Swieten Scale (VSS) score, and the Evans Index on clinical outcomes in patients over 80 years of age who underwent endovascular thrombectomy (EVT).

MATERIALS AND METHODS

We retrospectively analyzed anterior ischemic stroke (AIS) patients over 80 years of age who underwent EVT between May 2017 and April 2022. Good functional outcome was accepted as a 90-day modified Rankin Scale (mRS) score of 0-2. We constructed three models to compare to the mRS (model 1: THRIVE, CTA-ASPECT; model 2: THRIVE, CTA-ASPECT, Evans Index; model 3: THRIVE, CTA-ASPECT, Evans Index, VSS).

RESULTS

A total of 39 octogenarian patients with thrombolysis in cerebral infarction (TICI) 2c-3 recanalization were selected, and their 90-day mRS scores were compared. Of these, 19 patients (48%) showed good outcomes. In multivariable receiver operating characteristic (ROC) analyses, the AUC of model 1 was 0.797 (95% confidence interval [CI], 0.638-0.909), the AUC of model 2 was 0.862 (95% CI, 0.714-0.951), and the AUC of model 3 was 0.905 (95% CI, 0.768-0.975).

CONCLUSIONS

Evaluation of the THRIVE score, which measures vascular disease burden and stroke severity, together with the radiological parameters of ASPECTS score, VSS score, and the Evans Index, provides useful guidance in predicting the clinical outcomes of elderly AIS patients after EVT.

Reverse Translation to Develop Post-stroke Therapeutic Interventions during Mechanical Thrombectomy: Lessons from the BACTRAC Trial

The majority of strokes, approximately 87%, are ischemic in etiology with the remaining hemorrhagic in origin. Emergent large vessel occlusions (ELVOs) are a subtype of ischemic stroke accounting for approximately 30-40% of acute large vessel blockages. Treatment for ELVOs focuses on recanalization of the occluded vessel by time-sensitive administration of tissue plasminogen activator (tPA) or thrombus removal using mechanical thrombectomy. Although a great deal of time and resources have focused on translational stroke research, little progress has been made in the area of identifying additional new treatments for stroke. Translational limitations include difficulty simulating human comorbid conditions in animal models, as well as the temporal nature of stroke pathology. The Blood And Clot Thrombectomy Registry And Collaboration represents an ongoing tissue registry for thrombectomy patients and includes collection of intracranial arterial blood, systemic arterial blood, thrombi, as well as a series of clinical and radiographic data points for analysis. This chapter will explore the methodologies employed and results obtained from studying BACTRAC-derived human biological specimens and how they can inform translational experimental design in animal studies.

Thrombectomy-Capable Stroke Centre-A Key to Acute Stroke Care System Improvement? Retrospective Analysis of Safety and Efficacy of Endovascular Treatment in Cardiac Cathlab

The optimal structure of the acute ischaemic stroke treatment network is unknown and eagerly sought. To make it most effective, different treatment and transportation strategies have been developed and investigated worldwide. Since only a fraction of acute stroke patients with large vessel occlusion are treated, a new entity-thrombectomy-capable stroke centre (TCSC)-was introduced to respond to the growing demand for timely endovascular treatment. The purpose of this study was to present the early experience of the first 70 patients treated by mechanical means in a newly developed cardiac Cathlab-based TCSC. The essential safety and efficacy measures were recorded and compared with those reported in the invasive arm of the HERMES meta-analysis-the largest published dataset on the subject. We found no significant differences in terms of clinical and safety outcomes, such as early neurological recovery, level of functional independence at 90 days, symptomatic intracranial haemorrhage, parenchymal haematoma type 2, and mortality. These encouraging results obtained in the small endovascular centre may be an argument for the introduction of the TCSC into operating stroke networks to increase patient access to timely treatment and to improve clinical outcomes.

Sex differences in the utilization and outcomes of endovascular treatment after acute ischemic stroke: A systematic review and meta-analysis

Background

Studies of sex differences in the use and outcomes of endovascular treatment (EVT) for acute ischemic stroke report inconsistent results.

Methods

We systematically searched PubMed and Embase databases for studies examining sex-specific utilization of EVT for acute ischemic stroke published before 31 December 2021. Estimates were compared by study type: randomized clinical trials (RCTs) and non-RCTs (hospital-based, registry-based or administrative data). Random effects odds ratios (ORs) were generated to quantify sex differences in EVT use. To estimate sex differences in functional outcome on the modified Rankin scale after EVT, the female:male ratio of ORs and 95% confidence intervals (CIs) were obtained from ordinal or binary analysis.

Results

6,396 studies were identified through database searching, of which 594 qualified for a full review. A total of 51 studies (36 non-RCT and 15 RCTs) reporting on sex-specific utilization of EVT were included, and of those 10 estimated the sex differences of EVT on functional outcomes. EVT use was similar in women and men both in non-RCTs (OR: 1.03, 95% CI: 0.96-1.11) and RCTs (1.02, 95% CI: 0.89-1.16), with consistent results across years of publication and regions of study, except that in Europe EVT treatment was higher in women than men (1.15, 95% CI: 1.13-1.16). No sex differences were found in the functional outcome by either ordinal and binary analyses (ORs 0.95, 95% CI: 0.68-1.32] and 0.90, 95% CI: 0.65-1.25, respectively).

Conclusions

No sex differences in EVT utilization or on functional outcomes were evident after acute ischemic stroke from large-vessel occlusion. Further research may be required to examine sex differences in long-term outcomes, social domains, and quality of life.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=226100, identifier: CRD42021226100.

Identification of infarct core and ischemic penumbra using computed tomography perfusion and deep learning

Purpose

The size and location of infarct and penumbra are key to decision-making for acute ischemic stroke (AIS) management. CT perfusion (CTP) software estimate infarct and penumbra volume using contralateral hemisphere relative thresholding. This approach is not robust and widely contested by the scientific community. In this study, we investigate the use of deep learning-based algorithms to efficiently locate infarct and penumbra tissue on CTP hemodynamic maps.

Approach

CTP scans were retrospectively collected for 60 and 59 patients in the infarct only and infarct + penumbra substudies respectively. Commercial CTP software was used to generate cerebral blood flow, cerebral blood volume, mean transit time, time to peak, and delay time maps. U-Net-shaped architectures were trained to segment infarct or infarct + penumbra. Test-time-augmentation, ensembling, and watershed segmentation were used as postprocessing techniques. Segmentation performance was evaluated using Dice coefficients (DC) and mean absolute volume errors (MAVE).

Results

The algorithm segmented infarct tissue resulted in DC of 0.64 ± 0.03 (0.63, 0.65), and MAVE of 4.91 ± 0.94 (4.5, 5.32) mL. In comparison, the commercial software predicted infarct with a DC of 0.31 ± 0.17 (0.26, 0.36) and MAVE of 9.77 ± 8.35 (7.12, 12.42) mL. The algorithm was able to segment infarct + penumbra with a DC of 0.61 ± 0.04 (0.6, 0.63), and MAVE of 6.51 ± 1.37 (5.91, 7.11) mL. In comparison, the commercial software predicted infarct + penumbra with a DC of 0.3 ± 0.19 (0.25, 0.35) and MAVE of 9.18 ± 7.55 (7.25, 11.11) mL.

Conclusions

Use of deep learning algorithms to assess severity of AIS in terms of infarct and penumbra volume is precise and outperforms current relative thresholding methods. Such an algorithm would enhance the reliability of CTP in guiding treatment decisions.

EMAGINE-Study protocol of a randomized controlled trial for determining the efficacy of a frequency tuned electromagnetic field treatment in facilitating recovery within the subacute phase following ischemic stroke

Stroke is a leading cause of disability with limited effective interventions that improve recovery in the subacute phase. This protocol aims to evaluate the safety and efficacy of a non-invasive, extremely low-frequency, low-intensity, frequency-tuned electromagnetic field treatment [Electromagnetic Network Targeting Field (ENTF) therapy] in reducing disability and promoting recovery in people with subacute ischemic stroke (IS) with moderate-severe disability and upper extremity (UE) motor impairment. Following a sample-size adaptive design with a single interim analysis, at least 150 and up to 344 participants will be recruited to detect a 0.5-point (with a minimum of 0.33 points) difference on the modified Rankin Scale (mRS) between groups with 80% power at a 5% significance level. This ElectroMAGnetic field Ischemic stroke-Novel subacutE treatment (EMAGINE) trial is a multicenter, double-blind, randomized, sham-controlled, parallel two-arm study to be conducted at approximately 20 United States sites, and enroll participants with subacute IS and moderate-severe disability with UE motor impairment. Participants will be assigned to active (ENTF) or sham treatment, initiated 4-21 days after stroke onset. The intervention, applied to the central nervous system, is designed for suitability in multiple clinical settings and at home. Primary endpoint is change in mRS score from baseline to 90 days post-stroke. Secondary endpoints: change from baseline to 90 days post-stroke on the Fugl-Meyer Assessment - UE (lead secondary endpoint), Box and Block Test, 10-Meter Walk, and others, to be analyzed in a hierarchical manner. EMAGINE will evaluate whether ENTF therapy is safe and effective at reducing disability following subacute IS.

Trial registration

www.ClinicalTrials.gov, NCT05044507 (14 September 2021).

Sanhua decoction: Current understanding of a traditional herbal recipe for stroke

Both thrombolytic and endovascular therapies are optimal treatment options for patients with acute ischemic stroke, but only less than half of these patients can benefit from these treatments. Traditional Chinese medicine has a long history of successfully managing ischemic stroke using both herbal and physical therapeutics. Among herbal recipes, Sanhua decoction (SHD) is one of the classical prescriptions for ischemic stroke. The present review aimed to summarize evidence from both clinical and basic research to demonstrate its efficacy in managing ischemic stroke and the potential mechanisms underlying its therapeutic effects, which will provide evidence on the therapeutic effect of this herbal recipe and guide future studies on this recipe. SHD is composed of four herbs, Rheum palmatum L. [Polygonaceae], Magnolia officinalis Rehder & E.H.Wilson [Magnoliaceae], Citrus × aurantium L. [Rutaceae], Hansenia weberbaueriana (Fedde ex H.Wolff) Pimenov & Kljuykov [Apiaceae]. We found that the majority of clinical studies on SHD are case reports and they showed positive therapeutic effect of SHD on both acute and chronic ischemic stroke. There are over 40 bioactive compounds identified in SHD, but few experimental studies have examined their individual molecular mechanisms. As an extract of SHD, it improves neurological functions through suppressing inflammation, protecting the blood brain barrier from degradation, restoring the number of neural stem cells, inhibiting apoptosis and brain edema, scavenging oxygen free radicals, and regulating the brain-gut axis. These will lay the theoretical foundation for future studies on this prescription and its clinical application. Future research may need to confirm its clinical efficacy in large-scale clinical trials and to disentangle its bioactive compounds and their potential mechanisms.

24-Hour Carotid Stent Patency and Outcomes After Endovascular Therapy: A Multicenter Study

BACKGROUND

Management of extracranial internal carotid artery steno-occlusive lesion during endovascular therapy remains debated. Stent occlusion within 24 hours of endovascular therapy is a frequent event after acute carotid artery stenting, and we currently lack large population results. We investigated the incidence, predictors, and clinical impact of stent occlusion after acute carotid artery stenting in current clinical practice.

METHODS

Patients treated by endovascular therapy with acute carotid artery stenting between 2015 and 2019 in 5 large-volume endovascular-capable centers were retrospectively analyzed. Patients were separated in 2 groups according to the stent patency at 24 hours after carotid artery stenting. We compared baseline characteristics, treatment modalities, and clinical outcome depending on 24-hour stent patency. Primary end point was favorable outcome, defined as a modified Rankin Scale score 0-2 at 3 months.

RESULTS

A stent occlusion was observed in 47/225 patients (20.9%). Patients with stent patency had a lower baseline National Institutes of Health Stroke Scale (median [interquartile range]: 13 [7-17] versus 18 [12-21]) and had more often stroke of atherothrombotic origin (77.0% versus 53.2%). A higher stent patency rate was found for patients treated with P2Y₁₂ antagonists at the acute phase (odds ratio [OR]' 2.95 [95% CI' 1.10-7.91]; P=0.026) and treated with angioplasty (OR' 2.42 [95% CI' 1.24-4.67]; P=0.008). A better intracranial angiographic reperfusion was observed in patients with 24-hour stent patency compared with patients without stent patency (OR' 8.38 [95% CI' 3.07-22.78]; P<0.001). Patients with a stent patency at 24 hours had a higher chance of favorable outcome (OR' 3.29 [95% CI, 1.66-6.52]; P<0.001) and a lower risk of death (OR' 0.32 [95% CI, 0.13-0.76]; P=0.009).

CONCLUSIONS

One out of 5 patients treated with carotid artery stenting during endovascular therapy presented a stent occlusion within 24 hours. This event was associated with worse functional outcome. Stroke etiology, P2Y₁₂ antagonist administration, quality of intracranial reperfusion, and angioplasty were associated with 24-hour stent patency.

In silico thrombectomy trials for acute ischemic stroke

BACKGROUND AND OBJECTIVE

In silico trials aim to speed up the introduction of new devices in clinical practice by testing device design and performance in different patient scenarios and improving patient stratification for optimizing clinical trials. In this paper, we demonstrate an in silico trial framework for thrombectomy treatment of acute ischemic stroke and apply this framework to compare treatment outcomes in different subpopulations and with different thrombectomy stent-retriever devices. We employ a novel surrogate thrombectomy model to evaluate the thrombectomy success in the in silico trial.

METHODS

The surrogate thrombectomy model, built using data from a fine-grained finite-element model, is a device-specific binary classifier (logistic regression), to estimate the probability of successful recanalization, the outcome of interest. We incorporate this surrogate model within our previously developed in silico trial framework and demonstrate its use with three examples of in silico clinical trials. The first trial is a validation trial for the surrogate thrombectomy model. We then present two exploratory trials: one evaluating the performance of a commercially available device based on the fibrin composition in the occluding thrombus and one comparing the performance of two commercially available stent retrievers.

RESULTS

The Validation Trial showed the surrogate thrombectomy model was able to reproduce a similar recanalization rate as the real-life MR CLEAN trial (p=0.6). Results from the first exploratory trial showed that the chance of successful thrombectomy increases with higher blood cell concentrations in the thrombi, which is in line with observations from clinical data. The second exploratory trial showed improved recanalization success with a newer stent retriever device; however, these results require further investigation as the surrogate model for the newer stent retriever device has not yet been validated.

CONCLUSIONS

In this novel study, we have shown that in silico trials have the potential to help inform medical device developers on the performance of a new device and may also be used to select populations of interest for a clinical trial. This would reduce the time and costs involved in device development and traditional clinical trials.

Viz.ai Implementation of Stroke Augmented Intelligence and Communications Platform to Improve Indicators and Outcomes for a Comprehensive Stroke Center and Network

BACKGROUND AND PURPOSE

Comprehensive stroke centers continually strive to narrow neurointerventional time metrics. Although process improvements have been put in place to streamline workflows, complex pathways, disparate imaging locations, and fragmented communications all highlight the need for continued improvement.

MATERIALS AND METHODS

This Quality Improvement Initiative (VISIION) was implemented to assess our transition to the Viz.ai platform for immediate image review and centralized communication and their effect on key performance indicators in our comprehensive stroke center. We compared periods before and following deployment. Sequential patients having undergone stroke thrombectomy were included. Both direct arriving large-vessel occlusion and Brain Emergency Management Initiative telemedicine transfer large-vessel occlusion cases were assessed as were subgroups of OnHours and OffHours. Text messaging thread counts were compared between time periods to assess communications. Mann-Whitney U and Student t tests were used.

RESULTS

Eighty-two neurointerventional cases were analyzed pre vs. post time periods: (DALVO-OnHours 7 versus 7, DALVO-OffHours 10 versus 5, BEMI-OnHours 13 versus 6, BEMI-OffHours 17 versus 17). DALVO-OffHours had a 39% door-to-groin reduction (157 versus 95 minutes, P = .009). DALVO-All showed a 32% reduction (127 versus 86 minutes, P = .006). BEMI-All improved 33% (42 versus 28 minutes, P = .036). Text messaging thread counts improved 30% (39 versus 27, P = .04).

CONCLUSIONS

There was an immediate improvement following Viz.ai implementation for both direct arriving and telemedicine transfer thrombectomy cases. In the greatest opportunity subset (direct arriving large-vessel occlusion-OffHours: direct arriving cases requiring team mobilization off-hours), we noted a 39% improvement. With Viz.ai, we noted that immediate access to images and streamlined communications improved door-to-groin time metrics for thrombectomy. These results have implications for future care processes and can be a model for centers striving to optimize workflow and improve thrombectomy timeliness.

Updates in mechanical thrombectomy

Stroke is a leading cause of morbidity and mortality. The advent of mechanical thrombectomy has largely improved patient outcomes. This article reviews the features and outcomes associated with aspiration, stent retrievers, and combination catheters used in current practice. There is also a discussion on clinical considerations based on anatomical features and clot composition. The reperfusion grading scale and outcome metrics commonly used following thrombectomy when a patient is still in the hospital are reviewed. Lastly, there are proposed discharge and outpatient follow-up goals in caring for patients hospitalized for a stroke.

Investigating Outcomes Post-Endovascular Thrombectomy in Acute Stroke Patients With Cancer

BACKGROUND AND OBJECTIVES

Cancer is a common comorbidity in patients with acute ischemic stroke (AIS). Randomized controlled trials that established endovascular thrombectomy (EVT) as the standard of care for large vessel occlusion generally excluded patients with cancer. As such, the clinical benefits of endovascular thrombectomy in the cancer population are currently poorly established. We examine clinical outcomes of patients with cancer who underwent EVT using a large inpatient database, the National Inpatient Sample (NIS).

METHODS

The NIS was queried for AIS admission between 2016 and 2019, and patients with cancer were identified. Baseline demographics, comorbidities, reperfusion therapies, and outcomes were compared between patients with AIS with and without cancer. For patients who underwent EVT, propensity score matching was used to study primary outcomes such as risk of intracranial hemorrhage, hospital length of stay, and discharge disposition.

RESULTS

During the study period, 2,677,200 patients were hospitalized with AIS, 228,800 (8.5%) of whom had a diagnosis of cancer. A total of 132,210 patients underwent EVT, of which 8,935 (6.8%) had cancer. Over 20% of patients with cancer who underwent EVT had a favorable outcome of a routine discharge home without services. On adjusted propensity score analysis, patients with cancer who underwent EVT had similar rates of intracranial hemorrhage (OR 1.03, CI 0.79-1.33, p = 0.90) and odds of a discharge home, with a significantly higher rate of prolonged hospitalization greater than 10 days (OR 1.34, CI 1.07-1.68, p = 0.01). Compared with patients without cancer, patients with metastatic cancer who underwent EVT also had similar rates of intracranial hemorrhage (OR 1.03, CI 0.64-1.67, p = 1.00) and likelihood of routine discharge (OR 0.83, CI 0.51-1.35, p = 0.54) but higher rates of in-hospital mortality (OR 2.72, CI 1.52-4.90, p < 0.01).

DISCUSSION

Our findings show that in contemporary medical practice, patients with acute stroke with comorbid cancer or metastatic cancer who undergo endovascular thrombectomy have similar rates of intracranial hemorrhage and favorable discharges as patients without cancer. This suggests that patients with AIS who meet the criteria for reperfusion therapy may be considered in the setting of a comorbid cancer diagnosis.

Recycled Translation: Repurposing Drugs for Stroke

Stroke, which continues to be a leading cause of death and long-term disability worldwide, has often been described as a clinical graveyard. While multiple small molecule therapeutics have undergone clinical trials in stroke, currently only one Food and Drug Administration (FDA)-approved medication exists for the treatment of stroke, the biological, recombinant tissue plasminogen activator (rt-PA). Repurposing of therapeutics which have previously gained FDA approval for alternative indications serves as a prospective option for stroke therapeutic translation. In contrast to de novo drug development, repurposing strategies have patient-centered and economic advantages. These include increased safety, increased chance of approval, decreased time to approval, and decreased capital investment. Presently, 37 active stroke clinical trials utilize repurposed therapeutics with various initial indications and dosing paradigms. The currently studied repurposed therapeutics fall into six mechanistic categories: (1) anticoagulation; (2) vasculature integrity, response, or red blood cell (RBC) alterations; (3) immune system regulation; (4) neurotransmission; and (5) neuroprotection. Directed hypothesis-driven computational investigation utilizing drug databases, in silico drug-protein interaction modeling, genomic data, and consensus methodology can determine if the current mechanistic repurposing categories have the highest chance of translational success or if other mechanistic avenues should be explored. With this increased focus on repurposed therapeutic strategies over de novo strategies, evolution and optimization of regulatory protections are needed to incentivize innovators and investigators.

Timing of symptomatic intracranial hemorrhage after endovascular stroke treatment

INTRODUCTION

Little is known about the timing of occurrence of symptomatic intracranial hemorrhage (sICH) after endovascular therapy (EVT) for acute ischemic stroke. A better understanding could optimize in-hospital surveillance time points and duration. The aim of this study was to delineate the probability of sICH over time and to identify factors associated with its timing.

PATIENTS AND METHODS

We retrospectively analyzed data from the Dutch MR CLEAN trial and MR CLEAN Registry. We included adult patients who underwent EVT for an anterior circulation large vessel occlusion within 6.5 h of stroke onset. In patients with sICH (defined as ICH causing an increase of ⩾4 points on the National Institutes of Health Stroke Scale [NIHSS]), univariable and multivariable linear regression analysis was used to identify factors associated with the timing of sICH. This was defined as the time between end of EVT and the time of first CT-scan on which ICH was seen as a proxy.

RESULTS

SICH occurred in 205 (6%) of 3391 included patients. Median time from end of EVT procedure to sICH detection on NCCT was 9.0 [IQR 2.9-22.5] hours, with a rapidly decreasing incidence after 24 h. None of the analyzed factors, including baseline NIHSS, intravenous alteplase treatment, and poor reperfusion at the end of the procedure were associated with the timing of sICH.

CONCLUSION

SICHs primarily occur in the first hours after EVT, and less frequently beyond 24 h. Guidelines that recommend to perform frequent neurological assessments for at least 24 h after intravenous alteplase treatment can be applied to ischemic stroke patients treated with EVT.

Agreement of three CT perfusion software packages in patients with acute ischemic stroke: A comparison with RAPID

PURPOSE

To compare ischemic core volume (ICV) and penumbra volume (PV) measured by MIStar, F-STROKE, and Syngo.via with that measured by RAPID in acute ischemic stroke (AIS), and their concordance in selecting patients for endovascular thrombectomy (EVT).

METHODS

Computed tomography perfusion (CTP) data were processed with four software packages. Bland-Altman analysis and intraclass correlation coefficient (ICC) were performed to evaluate their agreement in quantifying ICV and PV. Kappa test was conducted to assess consistency in the selection of EVT candidates. The correlation between predicted ICV and segmented final infarct volume (FIV) on follow-up images was investigated.

RESULTS

A total of 91 patients were retrospectively included. F-STROKE had the best consistency with RAPID (ICV: ICC = 0.97; PV: ICC = 0.84) and Syngo.via had the worst consistency (ICV: ICC = 0.77; PV: ICC = 0.66). F-STROKE had the narrowest limits of agreements both in ICV (-27.02, 24.40 mL) and PV (-85.59, 101.80 mL). When selecting EVT candidates, MIStar (kappa = 0.71-0.88) and F-STROKE (kappa = 0.84-0.90) had good to excellent consistency with RAPID, while Syngo.via had poor consistency (kappa = 0.20-0.41). ICV predicted by MIStar was correlated strongest with FIV (r = 0.77).

CONCLUSIONS

F-STROKE is most consistent with RAPID in quantitative ICV and PV. F-STROKE and MIStar exhibit similar EVT candidate selection to RAPID. Syngo.via, for its part, seems to have overestimated ICV and underestimated PV, leading to an overly restrictive selection of EVT candidates.

Artificial intelligence-based methods for fusion of electronic health records and imaging data

Healthcare data are inherently multimodal, including electronic health records (EHR), medical images, and multi-omics data. Combining these multimodal data sources contributes to a better understanding of human health and provides optimal personalized healthcare. The most important question when using multimodal data is how to fuse them-a field of growing interest among researchers. Advances in artificial intelligence (AI) technologies, particularly machine learning (ML), enable the fusion of these different data modalities to provide multimodal insights. To this end, in this scoping review, we focus on synthesizing and analyzing the literature that uses AI techniques to fuse multimodal medical data for different clinical applications. More specifically, we focus on studies that only fused EHR with medical imaging data to develop various AI methods for clinical applications. We present a comprehensive analysis of the various fusion strategies, the diseases and clinical outcomes for which multimodal fusion was used, the ML algorithms used to perform multimodal fusion for each clinical application, and the available multimodal medical datasets. We followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) guidelines. We searched Embase, PubMed, Scopus, and Google Scholar to retrieve relevant studies. After pre-processing and screening, we extracted data from 34 studies that fulfilled the inclusion criteria. We found that studies fusing imaging data with EHR are increasing and doubling from 2020 to 2021. In our analysis, a typical workflow was observed: feeding raw data, fusing different data modalities by applying conventional machine learning (ML) or deep learning (DL) algorithms, and finally, evaluating the multimodal fusion through clinical outcome predictions. Specifically, early fusion was the most used technique in most applications for multimodal learning (22 out of 34 studies). We found that multimodality fusion models outperformed traditional single-modality models for the same task. Disease diagnosis and prediction were the most common clinical outcomes (reported in 20 and 10 studies, respectively) from a clinical outcome perspective. Neurological disorders were the dominant category (16 studies). From an AI perspective, conventional ML models were the most used (19 studies), followed by DL models (16 studies). Multimodal data used in the included studies were mostly from private repositories (21 studies). Through this scoping review, we offer new insights for researchers interested in knowing the current state of knowledge within this research field.

Advances in cerebral perfusion imaging techniques in acute ischemic stroke

The application of cerebral perfusion imaging has demonstrated significant assessment benefits and an ability to establish an appropriate triage of patients with acute ischemic stroke (AIS) and large artery occlusion (LAO) in the extended time window. Computed tomography perfusion (CTP) and magnetic resonance imaging (MRI) are routinely used to determine the ischemic core, as well as the tissue at risk, to aid in therapeutic decision-making. However, the time required to transport patients to imaging extends the door-to-reperfusion time. C-arm cone-beam CT (CBCT) is a novel tomography technology that combines 2D radiography and 3D CT imaging based on the digital subtraction angiography platform. In comparison with CT or MRI perfusion techniques, CBCT combined with catheterized angiogram or therapy can serve as a "one-stop-shop" for the diagnosis and treatment of AIS, and greatly reduce the door to reperfusion time. Here, we review the current evidence on the efficacy and theoretical basis of CBCT, as well as other perfusion techniques, with the purpose to assist clinicians to establish an effective and repaid workflow for patients with AIS and LAO in clinical practice.

Systematic Review of Existing Stroke Guidelines: Case for a Change

Methods

We systematically searched for guideline recommendation on the day-to-day use of peripheral inflammatory markers such as NLR published in the English language between January 1, 2005, and October 2020. Any other evidence of system biology-based approach or recommendation was explored within the selected guidelines for this scoping review. Only the latest guideline per writing group was selected. Each guideline was analyzed independently by 2 to 4 authors to determine clinical scenarios explained/given, scientific evidence used, and recommendations presented in the context of system biology.

Results

The scoping review found 2,911 titles at the beginning of the search. Final review included with 15 guidelines. Stroke-related organizations wrote sixty-five percent of the guidelines while national ministries wrote a fewer number of guidelines. We were primarily interested in recommendations for acute management in AIS published in the English language. Fifteen eligible guidelines were identified from 15 different countries/regions. None of the guidelines recommended the routine use of peripheral markers of inflammation, such as NLR, among their acute assessment and management recommendations. None of the existing guidelines explored the system biology approach to one of the most complex diseases affecting the human brain, stroke.

Conclusions

This systematic review has identified a significant evidence-practice gap in all existing national stroke guidelines published in English medium as of October 2020. These guidelines included the only current "living stroke guidelines," stroke guidelines from Australia with a real opportunity to modernize the living stroke guidelines with systems biology approach, and provide 2020 vision towards better stroke care globally. Investigation of complex disease such as stroke is best served through a systems biology approach. One of the easiest places to start is simple blood tests such as total white cell count and NLR. Systems biology approach point us towards simple tools such immune-inflammatory index (SII) and serial systemic immune inflammatory indices (SSIIi) which should pave the way for the stroke physician community address the challenges in systems biology approach in stroke care. These challenges include translating bench research to the bedside, managing big data (continuous pulse, blood pressure, sleep, oxygen saturation, progressive changes in NLR, SII, SSIIi, etc.). Working with an interdisciplinary team also provides a distinct advantage. Recent adoption of historic WHO-IGAP calls for immediate action. The 2022 World Brain Day campaign on Brain Health for All is the perfect opportunity to raise awareness and start the process.

FeMA: Feature matching auto-encoder for predicting ischaemic stroke evolution and treatment outcome

Although, predicting ischaemic stroke evolution and treatment outcome provide important information one step towards individual treatment planning, classifying functional outcome and modelling the brain tissue evolution remains a challenge due to data complexity and visually subtle changes in the brain. We propose a novel deep learning approach, Feature Matching Auto-encoder (FeMA) that consists of two stages, predicting ischaemic stroke evolution at one week without voxel-wise annotation and predicting ischaemic stroke treatment outcome at 90 days from a baseline scan. In the first stage, we introduce feature similarity and consistency objective, and in the second stage, we show that adding stroke evolution information increase the performance of functional outcome prediction. Comparative experiments demonstrate that our proposed method is more effective to extract representative follow-up features and achieves the best results for functional outcome of stroke treatment.