Endovascular treatment versus no endovascular treatment after 6-24 h in patients with ischaemic stroke and collateral flow on CT angiography (MR CLEAN-LATE) in the Netherlands: a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial

Cost-effectiveness of endovascular treatment after 6-24 h in ischaemic stroke patients with collateral flow on CT-angiography: A model-based economic evaluation of the MR CLEAN-LATE trial

BACKGROUND

The MR CLEAN-LATE trial has shown that patient selection for endovascular treatment (EVT) in the late window (6-24 h after onset or last-seen-well) based on the presence of collateral flow on CT-angiography is safe and effective. We aimed to assess the cost-effectiveness of late-window collateral-based EVT-selection compared to best medical management (BMM) over a lifetime horizon (until 95 years of age).

MATERIALS AND METHODS

A model-based economic evaluation was performed from a societal perspective in The Netherlands. A decision tree was combined with a state-transition (Markov) model. Health states were defined by the modified Rankin Scale (mRS). Initial probabilities at 3-months post-stroke were based on MR CLEAN-LATE data. Transition probabilities were derived from previous literature. Information on short- and long-term resource use and utilities was obtained from a study using MR CLEAN-LATE and cross-sectional data. All costs are expressed in 2022 euros. Costs and quality-adjusted life years (QALYs) were discounted at a rate of 4% and 1.5%, respectively. The effect of parameter uncertainty was assessed using probabilistic sensitivity analysis (PSA).

RESULTS

On average, the EVT strategy cost €159,592 (95% CI: €140,830-€180,154) and generated 3.46 QALYs (95% CI: 3.04-3.90) per patient, whereas the costs and QALYs associated with BMM were €149,935 (95% CI: €130,841-€171,776) and 2.88 (95% CI: 2.48-3.29), respectively. The incremental cost-effectiveness ratio per QALY and the incremental net monetary benefit were €16,442 and €19,710, respectively. At a cost-effectiveness threshold of €50,000/QALY, EVT was cost-effective in 87% of replications.

DISCUSSION AND CONCLUSION

Collateral-based selection for late-window EVT is likely cost-effective from a societal perspective in The Netherlands.

Noncontrast CT Selected Thrombectomy vs Medical Management for Late-Window Anterior Large Vessel Occlusion

BACKGROUND AND OBJECTIVES

There is uncertainty whether patients with large vessel occlusion (LVO) presenting in the late 6-hour to 24-hour time window can be selected for endovascular therapy (EVT) by noncontrast CT (NCCT) and CT angiography (CTA) for LVO detection. We evaluated the clinical outcomes of patients selected for EVT by NCCT compared with those medically managed in the extended time window.

METHODS

This multinational cohort study was conducted at 66 sites across 10 countries. Consecutive patients with proximal anterior LVO stroke selected for EVT by NCCT or medically managed and presenting within 6-24 hours of time last seen well (TSLW) from January 2014 to May 2022 were included. The primary end point was the 90-day ordinal shift in the modified Rankin Scale (mRS) score. Inverse probability treatment weighting (IPTW) and multivariable methods were used.

RESULTS

Of 5,098 patients screened, 839 patients were included, with a median (interquartile range) age of 75 (64-83) years; 455 (54.2%) were women. There were 616 patients selected to undergo EVT by NCCT (73.4%) and 223 (26.6%) who were medically managed. In IPTW analyses, there was a more favorable 90-day ordinal mRS shift in patients selected by NCCT to EVT vs those who were medically managed (odds ratio [OR] 1.99, 95% CI 1.53-2.59; p < 0.001). There were higher rates of 90-day functional independence (mRS 0-2) in the EVT group (40.1% vs 18.4%, OR 3.31, 95% CI 2.11-5.20; p < 0.001). sICH was nonsignificantly higher in the EVT group (8.5% vs 1.4%, OR 3.77, 95% CI 0.72-19.7, p = 0.12). Mortality at 90 days was lower in the EVT vs MM group (23.9% vs 32.3%, OR 0.61, 95% CI 0.45-0.83, p = 0.002).

DISCUSSION

In patients with proximal anterior LVO in the extended time window, there was a lower rate of disability and mortality in patients selected with NCCT and CTA to EVT compared with those who were medically managed. These findings support the use of NCCT as a simpler and more inclusive approach to patient selection in the extended window.

TRIAL REGISTRATION INFORMATION

This study was registered at ClinicalTrials.gov under NCT04096248.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with proximal anterior circulation occlusion presenting with ischemic stroke from 6 to 24 hours, compared with medical management, those undergoing thrombectomy based on NCCT have reduced disability and mortality at 90 days.

Education and training in neurology: developments and future challenges

BACKGROUND AND PURPOSE

Training and education is essential for best practice medicine and is especially important in a rapidly evolving field such as neurology. Due to improved imaging techniques and laboratory testing, there is a better understanding of the pathophysiology of diseases. As a result more treatments have become available. The most important developments in neurology over the last two decades and their effect on training and education are described. In addition, how future training should be aware of the challenges ahead of us is described.

METHODS

This is a narrative review describing developments and challenges based on personal experience and the literature.

RESULTS

Due to major developments in radiological and immunological testing, major changes have been seen in different subspecialties of neurology, including but not limited to, the treatment of ischaemic stroke, the development of new entities in the field of demyelinating diseases and auto-immune encephalitis, and diffuse glioma. These developments challenge the education and training in neurology with, ahead of us, technological developments, an aging population, and potentially more superspecialization.

CONCLUSION

Although there are differences in the training curricula between European countries, the developments and future challenges within the field of neurology are very similar. In the development of future curricula it is important to face these developments and challenges and to adapt to them.

A systematic review of randomized controlled trials of endovascular therapy for stroke on mortality and disability

BACKGROUND

Endovascular treatment (EVT) has become standard of care for patients with anterior circulation large vessel occlusion (LVO) stroke, with indications having recently expanded to late time-window and large ischemic core patients. There is conflicting evidence on whether EVT reduces mortality or only disability. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of EVT on mortality and severe disability.

METHODS

We systematically searched PubMed, Web of Science, Scopus, and Embase on November 15, 2023, to identify phase 3 RCTs comparing EVT to best medical treatment (BMT) in patients with anterior circulation LVO stroke in a common effects meta-analysis. The primary outcome was mortality at 3 months. Secondary outcomes were moderately severe or severe disability (modified Rankin Scale (mRS) score 4-5) at 3 months.

RESULTS

18 studies comparing EVT to BMT were included, with a total of 4309 patients; 2159 that were treated with EVT, and 2150 treated with BMT. Mortality was significantly lower in the EVT group than in the BMT group (odds ratio (OR): 0.81, 95% CI: 0.70-0.94). Proportions of moderately severe or severe disability (OR: 0.55, 95% CI: 0.48-0.62) were also significantly lower in patients treated with EVT.

CONCLUSIONS

This meta-analysis suggests that EVT reduces both mortality and moderately severe or severe disability in patients with anterior circulation LVO stroke.

Stroke

Stroke affects up to one in five people during their lifetime in some high-income countries, and up to almost one in two in low-income countries. Globally, it is the second leading cause of death. Clinically, the disease is characterised by sudden neurological deficits. Vascular aetiologies contribute to the most common causes of ischaemic stroke, including large artery disease, cardioembolism, and small vessel disease. Small vessel disease is also the most frequent cause of intracerebral haemorrhage, followed by macrovascular causes. For acute ischaemic stroke, multimodal CT or MRI reveal infarct core, ischaemic penumbra, and site of vascular occlusion. For intracerebral haemorrhage, neuroimaging identifies early radiological markers of haematoma expansion and probable underlying cause. For intravenous thrombolysis in ischaemic stroke, tenecteplase is now a safe and effective alternative to alteplase. In patients with strokes caused by large vessel occlusion, the indications for endovascular thrombectomy have been extended to include larger core infarcts and basilar artery occlusion, and the treatment time window has increased to up to 24 h from stroke onset. Regarding intracerebral haemorrhage, prompt delivery of bundled care consisting of immediate anticoagulation reversal, simultaneous blood pressure lowering, and prespecified stroke unit protocols can improve clinical outcomes. Guided by underlying stroke mechanisms, secondary prevention encompasses pharmacological, vascular, or endovascular interventions and lifestyle modifications.

The volume of steal phenomenon is associated with neurological deterioration in patients with large-vessel occlusion minor stroke not eligible for thrombectomy

INTRODUCTION

A significant number of patients who present with mild symptoms following large-vessel occlusion acute ischemic stroke (LVO-AIS) are currently considered ineligible for EVT. However, they frequently experience neurological deterioration during hospitalization. This study aimed to investigate the association between neurological deterioration and hemodynamic impairment by assessing steal phenomenon derived from blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) in this specific patient cohort.

PATIENTS AND METHODS

From the database of our single-center BOLD-CVR observational cohort study (June 2015-October 2023) we retrospectively identified acute ischemic stroke patients with admission NIHSS < 6, a newly detected large vessel occlusion of the anterior circulation and ineligible for EVT. Neurological deterioration during hospitalization as well as outcome at hospital discharge were rated with NIHSS score. We analyzed the association between these two outcomes and BOLD-CVR-derived steal phenomenon volume through regression analysis. Additionally, we investigated the discriminatory accuracy of steal phenomenon volume for predicting neurological deterioration.

RESULTS

Forty patients were included in the final analysis. Neurological deterioration occurred in 35% of patients. In the regression analysis, a strong association between steal phenomenon volume and neurological deterioration (OR 4.80, 95% CI 1.32-31.04, p = 0.04) as well as poorer NIHSS score at hospital discharge (OR 3.73, 95% CI 1.52-10.78, p = 0.007) was found. The discriminatory accuracy of steal phenomenon for neurological deterioration prediction had an AUC of 0.791 (95% CI 0.653-0.930).

DISCUSSION

Based on our results we may distinguish two groups of patients with minor stroke currently ineligible for EVT, however, showing hemodynamic impairment and exhibiting neurological deterioration during hospitalization: (1) patients exhibiting steal phenomenon on BOLD-CVR imaging as well as hemodynamic impairment on resting perfusion imaging; (2) patients exhibiting steal phenomenon on BOLD-CVR imaging, however, no relevant hemodynamic impairment on resting perfusion imaging.

CONCLUSION

The presence of BOLD-CVR derived steal phenomenon may aid to further study hemodynamic impairment in patients with minor LVO-AIS not eligible for EVT.

Proteomic analysis of jugular venous blood in acute large vessel occlusion stroke with futile recanalization

Futile recanalization (FR) after endovascular treatment (EVT) remains a significant challenge for acute ischemic stroke (AIS) with large vessel occlusion (LVO). The pathogenesis of FR has not been well elucidated. We prospectively enrolled anterior circulation LVO-AIS patients who achieved successful recanalization after EVT. The jugular venous blood ipsilateral to stroke was collected before and immediately after recanalization. Plasma proteomic analysis based on liquid chromatography-mass spectrometry was performed using data-independent acquisition method. Differentially expressed proteins (DEPs) among patients with or without FR in the whole or propensity score matching (PSM) cohorts were screened according to the absolute value of fold change ≥1.5 and P value <0.05. We identified 104 and 34 DEPs between patients with or without FR in the whole cohort and PSM cohort, respectively. Bioinformatic analysis indicated that the identified proteins were primarily related to specific biological processes including immune response, complement activation, oxidative stress, lipid metabolism, protein ubiquitylation as well as autophagy, suggesting that these may be mechanisms in FR pathogenesis. Collectively, we discovered proteins that may be potential research targets for FR. The combination of proteomic and bioinformatic analysis could provide a better understanding of the pathogenesis of FR in a comprehensive manner.

Brain imaging prior to thrombectomy in the late window of large vessel occlusion ischemic stroke: a systematic review and meta-analysis

PURPOSE

Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.

METHODS

We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0-2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.

RESULTS

Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88-1.03) and sICH (RR 1.26, 0.85-1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06-1.39).

CONCLUSION

For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window.

Overview of systematic reviews comparing endovascular to best medical treatment for large-vessel occlusion acute ischaemic stroke: an umbrella review

Background

The literature on endovascular treatment (EVT) for large-vessel occlusion (LVO) acute ischaemic stroke (AIS) has been rapidly increasing after the publication of positive randomized-controlled clinical trials (RCTs) and a plethora of systematic reviews (SRs) showing benefit compared to best medical therapy (BMT) for LVO.

Objectives

An overview of SRs (umbrella review) and meta-analysis of primary RCTs were performed to summarize the literature and present efficacy and safety of EVT.

Design and methods

MEDLINE via Pubmed, Embase and Epistemonikos databases were searched from January 2015 until 15 October 2023. All SRs of RCTs comparing EVT to BMT were included. Quality was assessed using Risk of Bias in Systematic Reviews scores and the RoB 2 Cochrane Collaboration tool, as appropriate. GRADE approach was used to evaluate the strength of evidence. Data were presented according to the Preferred Reporting Items for Overviews of Reviews statement. The primary outcome was 3-month good functional outcome [modified Rankin scale (mRS) score 0-2].

Results

Three eligible SRs and 4 additional RCTs were included in the overview, comprising a total of 24 RCTs, corresponding to 5968 AIS patients with LVO (3044 randomized to EVT versus 2924 patients randomized to BMT). High-quality evidence shows that EVT is associated with an increased likelihood of good functional outcome [risk ratio (RR) 1.78 (95% confidence interval (CI): 1.54-2.06); 166 more per 1000 patients], independent ambulation [mRS-scores 0-3; RR 1.50 (95% CI: 1.37-1.64); 174 more per 1000 patients], excellent functional outcome [mRS-scores 0-1; RR 1.90 (95% CI: 1.62-2.22); 118 more per 1000 patients] at 3 months. EVT was associated with reduced 3-month mortality [RR 0.81 (95% CI: 0.74-0.88); 61 less per 1000 patients] despite an increase in symptomatic intracranial haemorrhage [sICH; RR 1.65 (95% CI: 1.23-2.21); 22 more per 1000 patients].

Conclusion

In patients with AIS due to LVO in the anterior or posterior circulation, within 24 h from symptom onset, EVT improves functional outcomes and increases the chance of survival despite increased sICH risk.

Registration

PROSPERO Registration Number CRD42023461138.

Workflow and Outcome of Thrombectomy in Late Time Window: A Pooled Multicenter Analysis

BACKGROUND

We investigated the impact of workflow times on the outcomes of patients treated with endovascular thrombectomy (EVT) in the late time window.

METHODS

Individual patients' data who underwent EVT in the late time window (onset to imaging >6 hours) were pooled from seven registries and randomized clinical trials. Multiple time intervals were analyzed. Mixed-effects logistic regression was used to estimate the likelihood of functional independence at 90 days (modified Rankin Scale 0-2). Mixed-effects negative binomial regression was used to evaluate the relationship between patient characteristics and workflow time intervals.

RESULTS

608 patients were included. The median age was 70 years (IQR: 58-71), 307 (50.5%) were female, and 310 (53.2%) had wake-up strokes. Successful reperfusion was achieved in 493 (81.2%) patients, and 262 (44.9%) achieved 90-day mRS 0-2. The estimated odds of functional independence decreased by 13% for every 30 minute delay from emergency department (ED) arrival to imaging time and by 7% from ED arrival to the end of EVT in the entire cohort. Also, the estimated odds of functional independence decreased by 33% for every 30 minute delay in the interval from arterial puncture to end of EVT, 16% in the interval from arrival in ED to end of EVT and 6% in the interval from stroke onset to end of EVT among patients who had a wake-up stroke.

CONCLUSION

Faster workflow from ED arrival to end of EVT is associated with improved functional independence among stroke patients treated in the late window.

Neuroprotective role of lactate in a human in vitro model of the ischemic penumbra

In patients suffering from cerebral ischemic stroke, there is an urgent need for treatments to protect stressed yet viable brain cells. Recently, treatment strategies that induce neuronal activity have been shown to be neuroprotective. Here, we hypothesized that neuronal activation might maintain or trigger the astrocyte-to-neuron lactate shuttle (ANLS), whereby lactate is released from astrocytes to support the energy requirements of ATP-starved hypoxic neurons, and this leads to the observed neuroprotection. We tested this by using a human cell based in vitro model of the ischemic penumbra and investigating whether lactate might be neuroprotective in this setting. We found that lactate transporters are involved in the neuroprotective effect mediated by neuronal activation. Furthermore, we showed that lactate exogenously administered before hypoxia correlated with neuroprotection in our cellular model. In addition, stimulation of astrocyte with consequent endogenous production of lactate resulted in neuroprotection. To conclude, here we presented evidence that lactate transport into neurons contributes to neuroprotection during hypoxia providing a potential basis for therapeutic approaches in ischemic stroke.

Cost and Utility Estimates per Modified Rankin Scale Score up to 2 Years Post Stroke: Data to Inform Economic Evaluations From a Societal Perspective

OBJECTIVES

Model-based health economic evaluations of ischemic stroke are in need of cost- and utility estimates related to relevant outcome measures. This study aims to describe societal cost- and utility estimates per modified Rankin Scale (mRS)-score at different time points within 2 years post stroke.

METHODS

Included patients had a stroke between 3 months and 2.5 years ago. mRS and EQ-5D-5L were scored during a telephone interview. Based on the interview date, records were categorized into a time point: 3 months (3M; 3-6 months), 1 year (Y1; 6-18 months), or 2 years (Y2; 18-30 months). Patients completed a questionnaire on healthcare utilization and productivity losses in the previous 3 months. Initial stroke hospitalization costs were assessed. Mean costs and utilities per mRS and time point were derived with multiple imputation nested in bootstrapping. Cost at 3 months post stroke were estimated separately for endovascular treatment (EVT)-/non-EVT-patients.

RESULTS

1106 patients were included from 18 Dutch centers. At each time point, higher mRS-scores were associated with increasing average costs and decreasing average utility. Mean societal costs at 3M ranged from €11 943 (mRS 1, no EVT) to €55 957 (mRS 5, no EVT). For Y1, mean costs in the previous 3 months ranged from €885 (mRS 0) to €23 215 (mRS 5), and from €1655 (mRS 0) to €22 904 (mRS 5) for Y2. Mean utilities ranged from 0.07 to 0.96, depending on mRS and time point.

CONCLUSIONS

The mRS-score is a major determinant of costs and utilities at different post-stroke time points. Our estimates may be used to inform future model-based health economic evaluations.

Clinical Decision Support for Patients Presenting With Large Vessel Occlusion

A single center had a collaborative, multidisciplinary review to determine how to best implement new acute ischemic stroke trials involving large vessel occlusions. A flow diagram process map was created for clinical decision support. Patients were divided into four groups based upon size of infarct and timing of presentation. The process map, available in the electronic health record (EHR) for clinicians to reference, guides the selection of patients for endovascular therapy with neuroimaging. In addition, the process map offers guidance for discussions with families and patients experiencing large vessel occlusions with both small and large core infarcts. This manuscript describes the process of creating the process map through a multidisciplinary review and discussion, with points of controversy and how these were addressed.

Clinical uncertainty in large vessel occlusion ischemic stroke: does automated perfusion imaging make a difference? An intra-rater and inter-rater agreement study

BACKGROUND

Limited research exists regarding the impact of neuroimaging on endovascular thrombectomy (EVT) decisions for late-window cases of large vessel occlusion (LVO) stroke.

OBJECTIVE

T0 assess whether perfusion CT imaging: (1) alters the proportion of recommendations for EVT, and (2) enhances the reliability of EVT decision-making compared with non-contrast CT and CT angiography.

METHODS

We conducted a survey using 30 patients drawn from an institutional database of 3144 acute stroke cases. These were presented to 29 Canadian physicians with and without perfusion imaging. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κG).

RESULTS

The percentage of EVT recommendations differed by 1.1% with or without perfusion imaging. Individual decisions changed in 21.4% of cases (11.3% against EVT and 10.1% in favor). Inter-rater agreement (κG) among the 29 raters was similar between non-perfusion and perfusion CT neuroimaging (κG=0.487; 95% CI 0.327 to 0.647 and κG=0.552; 95% CI 0.430 to 0.675). The 95% CIs overlapped with moderate agreement in both. Intra-rater agreement exhibited overlapping 95% CIs for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of raters in both groups.

CONCLUSIONS

Despite the minimal difference in overall EVT recommendations with either neuroimaging protocol one in five decisions changed with perfusion imaging. Regarding agreement we found that the use of automated CT perfusion images does not significantly impact the reliability of EVT decisions for patients with late-window LVO.

The impact of collateral therapeutics on stroke hemodynamics in normotensive and hypertensive rats: a step toward translation

Introduction

Stroke interventions that increase collateral flow have the potential to salvage penumbral tissue and increase the number of patients eligible for reperfusion therapy. We compared the efficacy of two different collateral therapeutics during transient middle cerebral artery occlusion (tMCAO) in normotensive and hypertensive rats.

Methods

The change in collateral and core perfusion was measured using dual laser Doppler in response to either a pressor agent (phenylephrine, 10 mg/kg iv or vehicle) or a collateral vasodilator (TM5441, 5 mg/kg iv or vehicle) given 30 min into tMCAO in male Wistar and spontaneously hypertensive rats (SHRs).

Results

Pressor therapy increased collateral flow in the Wistar rats but was ineffective in the SHRs. The increase in collateral flow in the Wistar rats was associated with impaired cerebral blood flow autoregulation (CBFAR) that was intact in the SHRs. TM5441 caused a decrease in collateral perfusion in the Wistar rats and a modest increase in the SHRs. The pressor therapy reduced early infarction in both groups but increased edema in the SHRs, whereas TM5441 did not have any beneficial effects in either group.

Conclusions

Thus, the pressor therapy was superior to a collateral vasodilator in increasing collateral flow and improving outcomes in the Wistar rats, likely due to pial collaterals that were pressure passive; the lack of CBF response in the SHRs to pressor therapy was likely due to intact CBFAR that limited perfusion. While TM5441 modestly increased CBF in the SHRs but not in the Wistar rats, it did not have a beneficial effect on stroke outcomes. These results suggest that collateral therapies may need to be selected for certain comorbidities.

Absent leptomeningeal collateralization is associated with greatest benefit from mechanical thrombectomy in the 6-24 hour time window

INTRODUCTION

The impact of leptomeningeal collateralization on the efficacy of mechanical thrombectomy (MT) in patients with anterior circulation large vessel occlusion (aLVO) presenting in the 6-24 h time window remains poorly elucidated.

PATIENTS AND METHODS

Retrospective multicenter study of aLVO patients presenting between 6 and 24 h after stroke onset who received MT plus Best Medical Treatment (BMT) or BMT alone. Leptomeningeal collateralization was assessed using single-phase computed tomography angiography (grade 0: no filling; grade 1: filling ⩽50%; grade 2: filling >50% but <100%; grade 3: filling 100% of the occluded territory). Inverse probability of treatment weighted ordinal regression was performed to assess the association between treatment and shift of the modified Rankin Scale (mRS) score toward lower categories at 3 months. We used interaction analysis to explore differential treatment effects on functional outcomes (probabilities for each mRS subcategory at 3 months) at different collateral grades.

RESULTS

Among 363 included patients, 62% received MT + BMT. Better collateralization was associated with better functional outcomes at 3 months in the BMT alone group (collateral grade 1 vs 0: acOR 5.06, 95% CI 2.33-10.99). MT + BMT was associated with higher odds of favorable functional outcome at 3 months (acOR 1.70, 95% CI 1.11-2.62) which was consistent after adjustment for collateral status (acOR 1.54, 95% CI 1.01-2.35). Regarding treatment effect modification, patients with absent collateralization had higher probabilities for a mRS of 0-4 and a lower mortality at 3 months for the MT + BMT group.

DISCUSSION AND CONCLUSION

In the 6-to-24-h time window, aLVO patients with absent leptomeningeal collateralization benefit most from MT + BMT, indicating potential advantages for this group despite their poorer baseline prognosis.

Early neurological deterioration in patients with acute ischemic stroke is linked to unfavorable cerebral venous outflow

INTRODUCTION

Early neurological deterioration (END) is associated with poor outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). Causes of END after mechanical thrombectomy (MT) include unsuccessful recanalization and reperfusion hemorrhages. However, little is known about END excluding the aforementioned causes. We aimed to investigate factors associated with unexplained END (ENDunexplained) with regard to the cerebral collateral status.

PATIENTS AND METHODS

Multicenter retrospective study of AIS-LVO patients with successful MT (mTICI 2b-3). On admission CT angiography (CTA), pial arterial collaterals and venous outflow (VO) were assessed using the modified Tan-Scale and the Cortical Vein Opacification Score (COVES), respectively. ENDunexplained was defined as an increase in NIHSS score of ⩾ 4 within the first 24 hours after MT without parenchymal hemorrhage on follow-up imaging. Multivariable regression analyses were performed to examine factors of ENDunexplained and unfavorable functional outcome (modified Rankin Scale score 3-6).

RESULTS

A total of 620 patients met the inclusion criteria. ENDunexplained occurred in 10% of patients. While there was no significant difference in pial arterial collaterals, patients with ENDunexplained exhibited more often unfavorable VO (81% vs. 53%; P < 0.001). Unfavorable VO (aOR [95% CI]; 2.56 [1.02-6.40]; P = 0.045) was an independent predictor of ENDunexplained. ENDunexplained was independently associated with unfavorable functional outcomes at 90 days (aOR [95% CI]; 6.25 [2.06-18.94]; P = 0.001).

DISCUSSION AND CONCLUSION

Unfavorable VO on admission CTA was associated with ENDunexplained. ENDunexplained was independently linked to unfavorable functional outcomes at 90 days. Identifying AIS-LVO patients at risk of ENDunexplained may help to select patients for intensified monitoring and guide to optimal treatment regimes.

Endovascular Approach in Treating Vertebrobasilar Insufficiency: A Systematic Review

Vertebrobasilar insufficiency (VBI) is a significant medical condition that results from a lack of adequate blood flow to the posterior circulation of the brain. The first-line treatment involves the use of antiplatelet therapy, but in cases where patients are not responsive to drug therapy, surgical management is the next viable option. In the past, open endarterectomy was the preferred surgical approach for treating critical VBI patients. However, due to its high mortality rates and severe peri-procedural complications, its usage has decreased. Instead, the endovascular approach has emerged as an alternative surgical option for resolving VBI. This review explores the current literature to assess the effectiveness of endovascular interventions in treating VBI patients. It also highlights potential complications and adverse effects associated with these treatments while identifying gaps in the current research that warrant further investigation. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to extensively search relevant literature on endovascular approaches for treating VBI patients on PubMed, BioMed Central, and ClinicalTrials.gov. The findings suggest that endovascular treatments have demonstrated significant technical success in treating VBI, with low mortality rates and minor adverse effects, such as intracranial hemorrhage and restenosis. The overall incidence of these complications is relatively low. Combining medical therapies with endovascular interventions has improved outcomes and reduced restenosis rates. However, there are methodological limitations and inconsistencies in the current literature that necessitate further investigation. Future research should focus on larger, randomized clinical trials and direct comparisons with other treatment options to obtain more conclusive evidence.

Redefining CT perfusion-based ischemic core estimates for the ghost core in early time window stroke

BACKGROUND AND PURPOSE

In large vessel occlusion (LVO) stroke patients, relative cerebral blood flow (rCBF)<30% volume thresholds are commonly used in treatment decisions. In the early time window, nearly infarcted but salvageable tissue volumes may lead to pretreatment overestimates of infarct volume, and thus potentially exclude patients who may otherwise benefit from intervention. Our multisite analysis aims to explore the strength of relationships between widely used pretreatment CT parameters and clinical outcomes for early window stroke patients.

METHODS

Patients from two sites in a prospective registry were analyzed. Patients with LVOs, presenting within 3 hours of last known well, and who were successfully reperfused were included. Primary short-term neurological outcome was percent National Institutes of Health Stroke Scale (NIHSS) change from admission to discharge. Secondary long-term outcome was 90-day modified Rankin score. Spearman's correlations were performed. Significance was attributed to p-value ≤.05.

RESULTS

Among 73 patients, median age was 66 (interquartile range 54-76) years. Among all pretreatment imaging parameters, rCBF<30%, rCBF<34%, and rCBF<38% volumes were significantly, inversely correlated with percentage NIHSS change (p<.048). No other parameters significantly correlated with outcomes.

CONCLUSIONS

Our multisite analysis shows that favorable short-term neurological recovery was significantly correlated with rCBF volumes in the early time window. However, modest strength of correlations provides supportive evidence that the applicability of general ischemic core estimate thresholds in this subpopulation is limited. Our results support future larger-scale efforts to liberalize or reevaluate current rCBF parameter thresholds guiding treatment decisions for early time window stroke patients.

Cost-Effectiveness of Late Endovascular Thrombectomy vs. Best Medical Management in a Clinical Trial Setting and Real-World Setting

BACKGROUND AND PURPOSE

To assess cost-effectiveness of late time-window endovascular treatment (EVT) in a clinical trial setting and a "real-world" setting.

METHODS

Data are from the randomized ESCAPE trial and a prospective cohort study (ESCAPE-LATE). Anterior circulation large vessel occlusion patients presenting > 6 hours from last-known-well were included, whereby collateral status was an inclusion criterion for ESCAPE but not ESCAPE-LATE. A Markov state transition model was built to estimate lifetime costs and quality-adjusted life-years (QALYs) for EVT in addition to best medical care vs. best medical care only in a clinical trial setting (comparing ESCAPE-EVT to ESCAPE control arm patients) and a "real-world" setting (comparing ESCAPE-LATE to ESCAPE control arm patients). We performed an unadjusted analysis, using 90-day modified Rankin Scale(mRS) scores as model input and analysis adjusted for baseline factors. Acceptability of EVT was calculated using upper/lower willingness-to-pay thresholds of 100,000 USD/50,000 USD/QALY.

RESULTS

Two-hundred and forty-nine patients were included (ESCAPE-LATE:n = 200, ESCAPE EVT-arm:n = 29, ESCAPE control-arm:n = 20). Late EVT in addition to best medical care was cost effective in the unadjusted analysis both in the clinical trial and real-world setting, with acceptability 96.6%-99.0%. After adjusting for differences in baseline variables between the groups, late EVT was marginally cost effective in the clinical trial setting (acceptability:49.9%-61.6%), but not the "real-world" setting (acceptability:32.9%-42.6%).

CONCLUSION

EVT for LVO-patients presenting beyond 6 hours was cost effective in the clinical trial setting and "real-world" setting, although this was largely related to baseline patient differences favoring the "real-world" EVT group. After adjusting for these, EVT benefit was reduced in the trial setting, and absent in the real-world setting.

The impact of large core and late treatment trials: An update on the modelled annual thrombectomy eligibility of UK stroke patients

INTRODUCTION

To support decisions about thrombectomy provision, we have previously estimated the annual UK population eligible for treatment as ∼10% of stroke admissions. Since then, eight further randomised trials that could alter the eligibility rate have reported in 2021-23. We updated our estimates of the eligible population from these trials and other recent studies.

PATIENTS AND METHODS

An updated decision tree describing the EVT eligible population for UK stroke admissions was produced. Decision criteria were derived from the highest level of evidence available. For nodes where no specific RCT data existed, evidence was obtained from the latest systematic review(s) or the highest quality observational data.

RESULTS

We estimate that 15,420 (approximately 15%) of admitted UK stroke patients are now eligible for thrombectomy, or 14,930 if advanced brain imaging using MRI/CT perfusion or collateral assessment were used in all patients. This is a 54% increase in our previous estimate in 2021. Over 50% of LAO strokes are now potentially eligible for thrombectomy. The increase in eligibility is principally due to a much larger cohort of later presenting and/or larger ischaemic core patients.

CONCLUSION

Most previously independent LAO stroke patients presenting within 24 h, even in the presence of a large ischaemic core on initial non-contrast CT, should be considered for thrombectomy with use of advanced brain imaging in those presenting beyond 12 h to identify salvageable penumbral brain tissue. Treatment in most patients remains critically time-dependent and our estimates should be interpreted with this in mind.

Initial experience with radiomics of carotid perivascular adipose tissue in identifying symptomatic plaque

Background

Carotid atherosclerotic ischemic stroke threatens human health and life. The aim of this study is to establish a radiomics model of perivascular adipose tissue (PVAT) around carotid plaque for evaluation of the association between Peri-carotid Adipose Tissue structural changes with stroke and transient ischemic attack.

Methods

A total of 203 patients underwent head and neck computed tomography angiography examination in our hospital. All patients were divided into a symptomatic group (71 cases) and an asymptomatic group (132 cases) according to whether they had acute/subacute stroke or transient ischemic attack. The radiomic signature (RS) of carotid plaque PVAT was extracted, and the minimum redundancy maximum correlation, recursive feature elimination, and linear discriminant analysis algorithms were used for feature screening and dimensionality reduction.

Results

It was found that the RS model achieved the best diagnostic performance in the Bagging Decision Tree algorithm, and the training set (AUC, 0.837; 95%CI: 0.775, 0.899), testing set (AUC, 0.834; 95%CI: 0.685, 0.982). Compared with the traditional feature model, the RS model significantly improved the diagnostic efficacy for identifying symptomatic plaques in the testing set (AUC: 0.834 vs. 0.593; Z = 2.114, p = 0.0345).

Conclusion

The RS model of PVAT of carotid plaque can be used as an objective indicator to evaluate the risk of plaque and provide a basis for risk stratification of carotid atherosclerotic disease.

Predicting 30-day mortality in intensive care unit patients with ischaemic stroke or intracerebral haemorrhage

BACKGROUND

Stroke patients admitted to an intensive care unit (ICU) follow a particular survival pattern with a high short-term mortality, but if they survive the first 30 days, a relatively favourable subsequent survival is observed.

OBJECTIVES

The development and validation of two prognostic models predicting 30-day mortality for ICU patients with ischaemic stroke and for ICU patients with intracerebral haemorrhage (ICH), analysed separately, based on parameters readily available within 24 h after ICU admission, and with comparison with the existing Acute Physiology and Chronic Health Evaluation IV (APACHE-IV) model.

DESIGN

Observational cohort study.

SETTING

All 85 ICUs participating in the Dutch National Intensive Care Evaluation database.

PATIENTS

All adult patients with ischaemic stroke or ICH admitted to these ICUs between 2010 and 2019.

MAIN OUTCOME MEASURES

Models were developed using logistic regressions and compared with the existing APACHE-IV model. Predictive performance was assessed using ROC curves, calibration plots and Brier scores.

RESULTS

We enrolled 14 303 patients with stroke admitted to ICU: 8422 with ischaemic stroke and 5881 with ICH. Thirty-day mortality was 27% in patients with ischaemic stroke and 41% in patients with ICH. Important factors predicting 30-day mortality in both ischaemic stroke and ICH were age, lowest Glasgow Coma Scale (GCS) score in the first 24 h, acute physiological disturbance (measured using the Acute Physiology Score) and the application of mechanical ventilation. Both prognostic models showed high discrimination with an AUC 0.85 [95% confidence interval (CI), 0.84 to 0.87] for patients with ischaemic stroke and 0.85 (0.83 to 0.86) in ICH. Calibration plots and Brier scores indicated an overall good fit and good predictive performance. The APACHE-IV model predicting 30-day mortality showed similar performance with an AUC of 0.86 (95% CI, 0.85 to 0.87) in ischaemic stroke and 0.87 (0.86 to 0.89) in ICH.

CONCLUSION

We developed and validated two prognostic models for patients with ischaemic stroke and ICH separately with a high discrimination and good calibration to predict 30-day mortality within 24 h after ICU admission.

TRIAL REGISTRATION

Trial registration: Dutch Trial Registry ( https://www.trialregister.nl/ ); identifier: NTR7438.

Clinical consequence of vessel perforations during endovascular treatment of acute ischemic stroke

PURPOSE

Endovascular treatment (EVT) of acute ischemic stroke can be complicated by vessel perforation. We studied the incidence and determinants of vessel perforations. In addition, we studied the association of vessel perforations with functional outcome, and the association between location of perforation on digital subtraction angiography (DSA) and functional outcome, using a large EVT registry.

METHODS

We included all patients in the MR CLEAN Registry who underwent EVT. We used DSA to determine whether EVT was complicated by a vessel perforation. We analyzed the association with baseline clinical and interventional parameters using logistic regression models. Functional outcome was measured using the modified Rankin Scale at 90 days. The association between vessel perforation and angiographic imaging features and functional outcome was studied using ordinal logistic regression models adjusted for prognostic parameters. These associations were expressed as adjusted common odds ratios (acOR).

RESULTS

Vessel perforation occurred in 74 (2.6%) of 2794 patients who underwent EVT. Female sex (aOR 2.0 (95% CI 1.2-3.2)) and distal occlusion locations (aOR 2.2  (95% CI 1.3-3.5)) were associated with increased risk of vessel perforation. Functional outcome was worse in patients with vessel perforation (acOR 0.38 (95% CI 0.23-0.63)) compared to patients without a vessel perforation. No significant association was found between location of perforation and functional outcome.

CONCLUSION

The incidence of vessel perforation during EVT in this cohort was low, but has severe clinical consequences. Female patients and patients treated at distal occlusion locations are at higher risk.

Does imaging of the ischemic penumbra have value in acute ischemic stroke with large vessel occlusion?

PURPOSE OF REVIEW

In this review, we summarize current evidence regarding potential benefits and limitations of using perfusion imaging to estimate presence and extent of irreversibly injured ischemic brain tissue ('core') and severely ischemic yet salvageable tissue ('penumbra') in acute stroke patients with large vessel occlusion (LVO).

RECENT FINDINGS

Core and penumbra volumes are strong prognostic biomarkers in LVO patients. Greater benefits of both intravenous thrombolysis and endovascular therapy (EVT) are observed in patients with small core and large penumbra volumes. However, some current definitions of clinically relevant penumbra may be too restrictive and exclude patients who may benefit from reperfusion therapies. Alongside other clinical and radiological factors, penumbral imaging may enhance the discussion regarding the benefit/risk ratio of EVT in common clinical situations, such as patients with large core - for whom EVT's benefit is established but associated with a high rate of severe disability -, or patients with mild symptoms or medium vessel occlusions - for whom EVT's benefit is currently unknown. Beyond penumbral evaluation, perfusion imaging is clinically relevant for optimizing patient's selection for neuroprotection trials.

SUMMARY

In an emerging era of precision medicine, perfusion imaging is a valuable tool in LVO-related acute stroke.

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.

Microsurgical thrombectomy: where the ancient art meets the new era

Mechanical thrombectomy (MT) is the leading treatment for acute large vessel occlusion (LVO). However, surgical thrombectomy (ST) may have a role in well selected LVO patients where MT failed to re-establish flow, the endovascular route is inaccessible, or where MT is a financially prohibitive or absent option (developing and poor countries). We compared the efficacy and efficiency between ST and MT, and described our operative experience and its potential application in the developing world. Clinical outcomes, procedural times, and efficacy of treatment were compared between the MT and ST of acute LVO between 2012 and 2022. Propensity score-matched analysis was also conducted to compare MT and ST. One-hundred nine patients fulfilled the study criteria (77 MTs vs 32 STs). Factors driving outcome were age (aOR: 0.95, 95%CI, 0.91-0.98), hemisphere side (aOR: 0.38, 95%CI, 0.15-0.96), and DWI-ASPECT (aOR: 1.39, 95%CI, 1.09-1.77) at presentation by the multivariate analysis. Times from door-start of procedure (P = 0.45) and start of procedure-recanalization (P = 0.13) were similar between treatment options. Propensity score-matched analysis found no significant difference for 2 treatment methods about time of door to recanalization (P = 0.155) and outcome (P = 0.221). The prognosticators of thrombectomy for acute LVO in patients with successful recanalization were age, affected hemisphere side, and DWI-ASPECT score. Our evidence shows that the efficacy of ST is similar to that of MT. There should be a place of ST for cases of mechanical failure or tandem cervical ICA and MCA occlusion. ST may be a temporizing LVO treatment option in healthcare systems where MT is inexistent or financially prohibitive to patients.

Perfusion vs non-perfusion computed tomography imaging in the late window of emergent large vessel ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Guidelines recommend the treatment of emergent large vessel ischemic stroke (ELVIS) patients presenting beyond 6 hours of last known well time with endovascular thrombectomy (EVT) based on perfusion computed tomography (CT) neuroimaging. We compared the outcomes (long-term good clinical outcomes, symptomatic intracranial hemorrhage (sICH), and mortality) of ELVIS patients according to the type of CT neuroimaging they underwent.

METHODS

We searched the following databases: Medline, Embase, CENTRAL, and Scopus from January 1, 2015, to June 14, 2023. We included studies of late-presenting ELVIS patients undergoing EVT that had with data for non-perfusion and perfusion CT neuroimaging. We followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Data were pooled using a random effects model.

RESULTS

We found 7 observational cohorts. Non-perfusion versus perfusion CT was not statistically significantly different for both long-term clinical (n = 3,224; RR: 0.96; 95% CI 0.86 to 1.06; I2 = 18%) and sICH (n = 3,724; RR: 1.08 95% CI 0.60 to 1.94; I2 = 76%). Perfusion CT had less mortality (n = 3874; RR: 1.22; 95% CI 1.07 to 1.40; I2 = 0%). The certainty of these findings is very low because of limitations in the risk of bias, indirectness, and imprecision domains of the Grading of Recommendations, Assessment, Development and Evaluations.

CONCLUSION

The use of either non-perfusion or perfusion CT neuroimaging may have little to no effect on long-term clinical outcomes and sICH for late-presenting EVT patients. Perfusion CT neuroimaging may be associated with a reduced the risk of mortality. Evidence uncertainty warrants randomized trial data.

CTA and CTP for Detecting Distal Medium Vessel Occlusions: A Systematic Review and Meta-analysis

BACKGROUND

The optimal imaging method for detecting distal medium vessel occlusions (DMVOs) remains undefined.

PURPOSE

The objective of this study is to compare the diagnostic performance of CTA with CTP in detecting DMVOs.

DATA SOURCES

We searched PubMed, EMBASE, Web of Science Core Collection, and Cochrane Central Register of Controlled Trials up to March 31, 2023 (PROSPERO: CRD42022344006).

STUDY SELECTION

A total of 12 studies reporting accuracy values of CTA and/or CTP were included, comprising 2607 patients with 479 cases (18.3%) of DMVOs.

DATA ANALYSIS

Pooled sensitivity and specificity of both imaging methods were compared using a random-effects model. Subgroup analyses were performed based on the technique used in CTA (multi or single-phase) and the subtype of DMVOs (M2-only vs. M2 and other DMVOs). We applied Quality Assessment of Diagnostic Accuracy (QUADAS-2) tool and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) quality assessment criteria.

DATA SYNTHESIS

CTA demonstrated significantly lower sensitivity compared to CTP in detecting DMVOs [0.74, 95%CI (0.63-0.82) vs. 0.89, 95% CI (0.82-0.93), P < 0.01]. When subgrouped into single-phase and multi-phase CTA, multi-phase CTA exhibited higher sensitivity for DMVO detection than single-phase CTA [0.91, 95%CI (0.85-0.94) vs. 0.64, 95%CI (0.56-0.71), P < .01], while reaching similar levels to CTP. The sensitivity of single-phase CTA substantially decreased when extending from M2 to other non-M2 DMVOs [0.74, 95%CI (0.63-0.83) vs. 0.61, 0.95%CI (0.53-0.68), P = .02].

LIMITATIONS

We identified an overall high risk of bias and low quality of evidence, attributable to the design and reference standards of most studies.

CONCLUSIONS

Our findings highlight a significantly lower sensitivity of single-phase CTA compared to multi-phase CTA and CTP in diagnosing DMVOs.

Immediate Carotid Artery Stenting or Deferred Treatment in Patients With Tandem Carotid Lesions Treated Endovascularly for Acute Ischaemic Stroke

Fifteen to 20% of patients with an acute ischaemic stroke have a tandem lesion defined by the combination of an intracranial large vessel thrombo-embolic occlusion and a high grade stenosis or occlusion of the ipsilateral internal carotid artery. These patients tend to have worse outcomes than patients with isolated intracranial occlusions, with higher rates of disability and death. The introduction of endovascular thrombectomy to treat the intracranial lesion clearly improved the outcome compared with treatment with intravenous thrombolysis alone. However, the best treatment strategy for managing the extracranial carotid artery lesion in patients with tandem lesions remains unknown. Current guidelines recommend carotid endarterectomy for patients with transient ischaemic attack or non-disabling stroke and moderate or severe stenosis of the internal carotid artery, within two weeks of the initial event, to prevent major stroke recurrence and death. Alternatively, the symptomatic carotid artery could be treated by endovascular placement of a stent during endovascular thrombectomy (EVT). This would negate the need for a second procedure, immediately reduce the risk of stroke recurrence, increase patient satisfaction, and could be cost effective. However, the administration of dual antiplatelet therapy could potentially increase the risk of symptomatic intracranial haemorrhage in patients with acute ischaemic stroke. Randomised controlled trials evaluating the efficacy and safety of immediate carotid artery stenting during EVT in acute stroke patients with tandem lesions are currently ongoing and will impact the current guidelines regarding the treatment of patients with acute ischaemic stroke due to these tandem lesions.

Endovascular therapy beyond 24 hours for anterior circulation large vessel occlusion or stenosis in acute ischemic stroke: a retrospective study

Background

To assess the clinical and safety outcomes of endovascular treatment (EVT) administered more than 24 h after the onset of symptoms in patients with acute ischemic stroke resulting from anterior circulation large-vessel occlusion or stenosis (AIS-ACLVO/S).

Methods

We enrolled consecutive AIS-ACLVO/S patients who received EVT in our hospital between January 2019 and February 2022 and divided them into two groups based on the time from AIS onset to EVT: EVT < 24 h group and EVT >24 h group. The successful reperfusion (modified thrombolysis in cerebral infarction, [mTICI] ≥2b), 90-day modified Rankin Scale score (mRS), intracranial hemorrhage (ICH), and symptomatic ICH (sICH), as well as mortality, were analyzed in the two groups of patients.

Results

A total of 239 patients were included in the study, with 214 patients in the EVT < 24 h group (67.8 ± 0.8 years, 126 males) and 25 patients in the EVT > 24 h group (62.80 ± 2.0 years, 22 males). Both groups were similar in terms of hypertension, diabetes history, responsible vessels, and Alberta stroke program early computed tomography scores (p > 0.05). However, the EVT < 24 h group had significantly higher age, history of atrial fibrillation, proportion of patients receiving intravenous thrombolysis, and NIHSS scores before EVT than the EVT > 24 h group. AIS etiology differed between the groups, with more cases of large artery atherosclerosis in the EVT > 24-h group and more cases of cardioembolism in the EVT < 24-h group. Successful reperfusion (mTICI ≥2b), ICH, and sICH were similar between the groups. The 90-day functional independence rate (mRS ≤ 2) was significantly higher in the EVT > 24-h than in the EVT < 24-h group (80% vs. 39.7%, p < 0.001), while the 90-day mortality rate was lower in the EVT > 24-h group (0% vs. 24.8%, p < 0.001).

Conclusion

In our study, we found that EVT beyond 24 h of symptom onset in patients selected with multimodal MR screening, was associated with high functional independence rates and low mortality. Larger or randomized studies are needed to confirm these findings.

Automated advanced imaging in acute ischemic stroke. Certainties and uncertainties

The purpose of this is study was to review pearls and pitfalls of advanced imaging, such as computed tomography perfusion and diffusion-weighed imaging and perfusion-weighted imaging in the selection of acute ischemic stroke (AIS) patients suitable for endovascular treatment (EVT) in the late time window (6-24 h from symptom onset). Advanced imaging can quantify infarct core and ischemic penumbra using specific threshold values and provides optimal selection parameters, collectively called target mismatch. More precisely, target mismatch criteria consist of core volume and/or penumbra volume and mismatch ratio (the ratio between total hypoperfusion and core volumes) with precise cut-off values. The parameters of target mismatch are automatically calculated with dedicated software packages that allow a quick and standardized interpretation of advanced imaging. However, this approach has several limitations leading to a misclassification of core and penumbra volumes. In fact, automatic software platforms are affected by technical artifacts and are not interchangeable due to a remarkable vendor-dependent variability, resulting in different estimate of target mismatch parameters. In addition, advanced imaging is not completely accurate in detecting infarct core, that can be under- or overestimated. Finally, the selection of candidates for EVT remains currently suboptimal due to the high rates of futile reperfusion and overselection caused by the use of very stringent inclusion criteria. For these reasons, some investigators recently proposed to replace advanced with conventional imaging in the selection for EVT, after the demonstration that non-contrast CT ASPECTS and computed tomography angiography collateral evaluation are not inferior to advanced images in predicting outcome in AIS patients treated with EVT. However, other authors confirmed that CTP and PWI/DWI postprocessed images are superior to conventional imaging in establishing the eligibility of patients for EVT. Therefore, the routine application of automatic assessment of advanced imaging remains a matter of debate. Recent findings suggest that the combination of conventional and advanced imaging might improving our selection criteria.

Priorities for Advancements in Neuroimaging in the Diagnostic Workup of Acute Stroke

STAIR XII (12th Stroke Treatment Academy Industry Roundtable) included a workshop to discuss the priorities for advancements in neuroimaging in the diagnostic workup of acute ischemic stroke. The workshop brought together representatives from academia, industry, and government. The participants identified 10 critical areas of priority for the advancement of acute stroke imaging. These include enhancing imaging capabilities at primary and comprehensive stroke centers, refining the analysis and characterization of clots, establishing imaging criteria that can predict the response to reperfusion, optimizing the Thrombolysis in Cerebral Infarction scale, predicting first-pass reperfusion outcomes, improving imaging techniques post-reperfusion therapy, detecting early ischemia on noncontrast computed tomography, enhancing cone beam computed tomography, advancing mobile stroke units, and leveraging high-resolution vessel wall imaging to gain deeper insights into pathology. Imaging in acute ischemic stroke treatment has advanced significantly, but important challenges remain that need to be addressed. A combined effort from academic investigators, industry, and regulators is needed to improve imaging technologies and, ultimately, patient outcomes.

Current and future trends in acute ischemic stroke treatment: direct-to-angiography suite, middle vessel occlusion, large core, and minor strokes

Since the publication of the landmark thrombectomy trials in 2015, the field of endovascular therapy for ischemic stroke has been rapidly growing. The very low number needed to treat to provide functional benefits shown by the initial randomized trials has led clinicians and investigators to seek to translate the benefits of endovascular therapy to other patient subgroups. Even if the treatment effect is diminished, currently available data has provided sufficient information to extend endovascular therapy to large infarct core patients. Recently, published data have also shown that sophisticated imaging is not necessary for late time- window patients. As a result, further research into patient selection and the stroke pathway now focuses on dramatically reducing door-to-groin times and improving outcomes by circumventing classical imaging paradigms altogether and employing a direct-to-angio suite approach for selected large vessel occlusion patients in the early time window. While the results of this approach mainly concern patients with severe deficits, there are further struggles to provide evidence of the efficacy and safety of endovascular treatment in minor stroke and large vessel occlusion, as well as in patients with middle vessel occlusions. The current lack of good quality data regarding these patients provides significant challenges for accurately selecting potential candidates for endovascular treatment. However, current and future randomized trials will probably elucidate the efficacy of endovascular treatment in these patient populations.

Efficacy and safety of bridging therapy versus direct thrombectomy for tandem lesions in acute stroke: A systematic review and meta-analysis

BACKGROUND

Current studies have concluded that MT (Mechanical Thrombectomy) is safe and effective for tandem lesions (TL). However, The benefit of bridging therapy for TL is controversial.

OBJECTIVE

To compare efficacy and safety between bridging therapy and direct thrombectomy of tandem lesions.

METHOD

We conducted a systematic review and meta-analysis of studies comparing bridging therapy versus direct thrombectomy among TL patients with regards to symptomatic intracerebral hemorrhage(sICH), Parenchymal hemorrhage (PH), 3-month mortality, modified Rankin Scale (mRS) score within 3 months, successful reperfusion, and excellent reperfusion. The meta-analysis of proportions was conducted with a common effects model.

RESULT

Five studies (n = 1198 patients) were identified for the systematic review. For safety outcomes, the bridging group had no significant difference in the rate of symptomatic intracranial hemorrhage (OR = 0.78, 95% CI = 0.49-1.25, P = 0.31) and the rate of PH (OR = 0.67, 95% CI = 0.39-1.13, P = 0.13) but significantly lower rate of 3-month mortality (OR = 0.53, 95% CI = 0.37-0.75, P = 0.0004) compared to the direct thrombectomy group. In terms of efficacy outcomes, the bridging therapy group had a significantly higher rate of 3- month good functional outcome (mRS 0-2) (OR = 1.76, 95% CI = 1.38-2.24, P < 0.00001) and successful recanalization (OR = 1.69, 95% CI = 1.27-2.25, P = 0.0003) but no significant difference in the rate of excellent recanalization(OR = 1.21, 95% CI = 0.91-1.59, P = 0.19) in patients with TL compared to direct thrombectomy group.

CONCLUSION

Bridging therapy is effective in improving the 3-month functional prognosis and increasing the rate of arterial recanalization without increasing the risk of intracranial hemorrhage in patients with TL compared to direct thrombectomy. A large multicentre clinical RCT is expected, as are advanced intravenous thrombolysis and endovascular thrombectomy techniques.

Blood Oxygenation Level-Dependent Cerebrovascular Reactivity-Derived Steal Phenomenon May Indicate Tissue Reperfusion Failure After Successful Endovascular Thrombectomy

In acute ischemic stroke due to large-vessel occlusion (LVO), the clinical outcome after endovascular thrombectomy (EVT) is influenced by the extent of autoregulatory hemodynamic impairment, which can be derived from blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR). BOLD-CVR imaging identifies brain areas influenced by hemodynamic steal. We sought to investigate the presence of steal phenomenon and its relationship to DWI lesions and clinical deficit in the acute phase of ischemic stroke following successful vessel recanalization.From the prospective longitudinal IMPreST (Interplay of Microcirculation and Plasticity after ischemic Stroke) cohort study, patients with acute ischemic unilateral LVO stroke of the anterior circulation with successful endovascular thrombectomy (EVT; mTICI scale ≥ 2b) and subsequent BOLD-CVR examination were included for this analysis. We analyzed the spatial correlation between brain areas exhibiting BOLD-CVR-associated steal phenomenon and DWI infarct lesion as well as the relationship between steal phenomenon and NIHSS score at hospital discharge.Included patients (n = 21) exhibited steal phenomenon to different extents, whereas there was only a partial spatial overlap with the DWI lesion (median 19%; IQR, 8-59). The volume of steal phenomenon outside the DWI lesion showed a positive correlation with overall DWI lesion volume and was a significant predictor for the NIHSS score at hospital discharge.Patients with acute ischemic unilateral LVO stroke exhibited hemodynamic steal identified by BOLD-CVR after successful EVT. Steal volume was associated with DWI infarct lesion size and with poor clinical outcome at hospital discharge. BOLD-CVR may further aid in better understanding persisting hemodynamic impairment following reperfusion therapy.

Evolving Clinical-Translational Investigations of Cerebroprotection in Ischemic Stroke

Ischemic stroke is a highly morbid disease, with over 50% of large vessel stroke (middle cerebral artery or internal carotid artery terminus occlusion) patients suffering disability despite maximal acute reperfusion therapy with thrombolysis and thrombectomy. The discovery of the ischemic penumbra in the 1980s laid the foundation for a salvageable territory in ischemic stroke. Since then, the concept of neuroprotection has been a focus of post-stroke care to (1) minimize the conversion from penumbra to core irreversible infarct, (2) limit secondary damage from ischemia-reperfusion injury, inflammation, and excitotoxicity and (3) to encourage tissue repair. However, despite multiple studies, the preclinical-clinical research enterprise has not yet created an agent that mitigates post-stroke outcomes beyond thrombolysis and mechanical clot retrieval. These translational gaps have not deterred the scientific community as agents are under continuous investigation. The NIH has recently promoted the concept of cerebroprotection to consider the whole brain post-stroke rather than just the neurons. This review will briefly outline the translational science of past, current, and emerging breakthroughs in cerebroprotection and use of these foundational ideas to develop a novel paradigm for optimizing stroke outcomes.

Aspiration thrombectomy with the Penumbra System for patients with stroke and late onset to treatment: a subset analysis of the COMPLETE registry

Background

The purpose of this study was to report the safety and performance of aspiration thrombectomy with the Penumbra System for patients with acute ischemic stroke (AIS) due to anterior circulation large vessel occlusion (LVO) and late onset to treatment.

Methods

This is a retrospective subset analysis of a global prospective multicenter registry (COMPLETE) that enrolled adults with AIS due to LVO and a pre-stroke modified Rankin Scale score (mRS) of 0 or 1 who were treated first-line with aspiration thrombectomy either alone (A Direct Aspiration First Pass Technique [ADAPT]) or in combination with the 3D Revascularization Device (ADAPT + 3D). This subset analysis included all patients in the registry who had anterior circulation LVO, an Alberta Stroke Program Early CT Score of at least 6, and late onset to treatment (>6 h from stroke onset to puncture).

Results

Of the 650 patients in the COMPLETE registry, 167 were included in this subset analysis. The rate of successful revascularization (modified thrombolysis in cerebral infarction score 2b-3 achieved) at the end of the procedure was 83.2%, the rate of good functional outcome (mRS 0-2) at 90 days was 55.4%, and the all-cause mortality rate at 90 days was 14.4%. No device-related serious adverse events (SAEs) occurred. Procedure-related SAEs occurred in 9 patients (5.4%) within 24 h and in 12 patients (7.2%) overall. The rate of successful revascularization was higher for patients treated first-line with ADAPT (88.0%) than for patients treated first-line with ADAPT + 3D (75.0%; p = 0.035); no significant difference was observed between the ADAPT and ADAPT + 3D groups for any other primary or secondary outcome.

Conclusion

For patients with AIS due to anterior circulation LVO and with late onset to treatment, aspiration thrombectomy with the Penumbra System appears to be safe and effective. The rates of good functional outcome and all-cause mortality from this study compared favorably with those rates from the medical management arms of the DAWN and DEFUSE-3 studies.

Clinical trial registration

https://www.clinicaltrials.gov, NCT03464565.

Endovascular Therapy for Acute Stroke: New Evidence and Indications

Endovascular therapy (EVT) has revolutionized the treatment of acute ischemic stroke. In the past few years, endovascular treatment indications have expanded to include patients being treated in the extended window, with large ischemic core infarction, basilar artery occlusion (BAO) thrombectomy, as demonstrated by several randomized clinical trials. Intravenous thrombolysis (IVT) bridging to mechanical thrombectomy has also been studied via several randomized clinical trials, with the overall results indicating that IVT should not be skipped in patients who are candidates for both IVT and EVT. Simplification of neuroimaging protocols in the extended window to permit non-contrast CT, CTA collaterals have also expanded access to mechanical thrombectomy, particularly in regions across the world where access to advanced imaging may not be available. Ongoing study of areas to develop include rescue stenting in patients with failed thrombectomy, medium vessel occlusion thrombectomy, and carotid tandem occlusions. In this narrative review, we summarize recent trials and key data in the treatment of patients with large ischemic core infarct, simplification of neuroimaging protocols for the treatment of patients presenting in the late window, bridging thrombolysis, and BAO EVT evidence. We also summarize areas of ongoing study including medium and distal vessel occlusion.

Thrombectomy with and without computed tomography perfusion imaging for large-vessel occlusion stroke in the extended time window: a meta-analysis of randomized clinical trials

Objective

In recent years, several studies have used computed tomography perfusion (CTP) to assess whether mechanical thrombectomy can be performed in patients with large-vessel occlusion (LVO) stroke in an extended time window. However, it has the disadvantage of being time-consuming and expensive. This study aimed to compare the impact of the CTP group with the non-CTP group [non-contrast CT (NCCT) ± CT angiography (CTA)] on the prognosis of this patient population.

Methods

A search of PubMed, EMBASE, and the Cochrane Library databases was conducted to collect randomized controlled trials (RCTs) comparing the two strategies. Outcome indicators and factors influencing prognosis were summarized by standardized mean differences, ratios, and relative risks with 95% confidence intervals using a random-effects model.

Results

A total of two RCTs were included in the combined analysis. There were no significant differences in the main outcome indicators (modified Rankin Scale score at 90 days, successful postoperative reperfusion rate) or the incidence of adverse events (90-day mortality and symptomatic intracranial hemorrhage) between the NCCT ± CTA and CTP groups. The time from the last puncture appeared to be significantly shorter in the NCCT ± CTA group than in the CTP group (SMD: -0.14; 95% CI: -0.24, -0.04). Among them, age (OR: 0.96; 95% CI: 0.94, 0.98), ASPECTS (OR: 1.18; 95% CI: 1.12, 1.24), NIHSS score (OR: 0.90; 95% CI: 0.89, 0.91), and diabetes (OR: 0.69; 95% CI: 0.54, 0.88) were associated with a 90-day independent functional outcome.

Conclusion

These findings suggest that the choice of NCCT ± CTA (without CTP) for the assessment of mechanical thrombectomy within 6-24 h after LVO in the anterior circulation is not significantly different from CTP; instead, the choice of NCCT ± CTA significantly reduces the time from onset to arterial puncture.

Advances in mechanical thrombectomy for acute ischaemic stroke

Mechanical thrombectomy is a ground breaking treatment for acute ischaemic stroke caused by occlusion of a large vessel. Its efficacy over intravenous thrombolysis has been proven in multiple trials with a lower number needed to treat than percutaneous coronary intervention for acute myocardial infarction. However, access to this key treatment modality remains limited with a considerable postcode lottery across the UK and many parts of the world. The evidence base for mechanical thrombectomy dates back to 2015. Since then, there have been important advances in establishing and widening the criteria for treatment. This narrative review aims to summarise the current evidence base and latest advances for physicians and academics with an interest in recanalisation treatments for acute ischaemic stroke.

Access to and application of recanalizing therapies for severe acute ischemic stroke caused by large vessel occlusion

BACKGROUND

Groundbreaking study results since 2014 have dramatically changed the therapeutic options in acute therapy for severe ischemic stroke caused by large vessel occlusion (LVO). The scientifically proven advances in stroke imaging and thrombectomy techniques have allowed to offer the optimal version or combination of best medical and interventional therapy to the selected patient, yielding favorable or even excellent clinical outcomes within time windows unheard of before. The provision of the best possible individual therapy has become a guideline-based gold standard, but remains a great challenge. With geographic, regional, cultural, economic and resource differences worldwide, optimal local solutions have to be strived for.

AIM

This standard operation procedure (SOP) is aimed to give a suggestion of how to give patients access to and apply modern recanalizing therapy for acute ischemic stroke caused by LVO.

METHOD

The SOP was developed based on current guidelines, the evidence from the most recent trials and the experience of authors who have been involved in the above-named development at different levels.

RESULTS

This SOP is meant to be a comprehensive, yet not too detailed template to allow for freedom in local adaption. It comprises all relevant stages in providing care to the patient with severe ischemic stroke such as suspicion and alarm, prehospital acute measures, recognition and grading, transport, emergency room workup, selective cerebral imaging, differential treatment by recanalizing therapies (intravenous thrombolysis, endovascular stroke treatmet, or combined), complications, stroke unit and neurocritical care.

CONCLUSIONS

The challenge of giving patients access to and applying recanalizing therapies in severe ischemic stroke may be facilitated by a systematic, SOP-based approach adapted to local settings.