Expanding indications for endovascular thrombectomy-how to leave no patient behind

Endovascular therapy in acute ischemic stroke with poor reperfusion is associated with worse outcomes compared with best medical management: a HERMES substudy

BACKGROUND

Functional outcomes in patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO) undergoing endovascular treatment (EVT) with poor reperfusion were compared with patients with AIS-LVO treated with best medical management only.

METHODS

Data are from the HERMES collaboration, a patient-level meta-analysis of seven randomized EVT trials. Baseline characteristics and functional outcomes (modified Rankin Scale (mRS) score at 90 days) were compared between patients with poor reperfusion (defined as modified Thrombolysis in Cerebral Infarction Score 0-1 on the final intracranial angiography run as assessed by the central imaging core laboratory) and patients in the control arm with multivariable logistic ordinal logistic regression adjusted for pre-specified baseline variables.

RESULTS

972 of 1764 patients from the HERMES collaboration were included in the analysis: 893 in the control arm and 79 in the EVT arm with final mTICI 0-1. Patients with poor reperfusion who underwent EVT had higher baseline National Institutes of Health Stroke Scale than controls (median 19 (IQR 15.5-21) vs 17 (13-21), P=0.011). They also had worse mRS at 90 days compared with those in the control arm in adjusted analysis (median 4 (IQR 3-6) vs median 4 (IQR 2-5), adjusted common OR 0.59 (95% CI 0.38 to 0.91)). Symptomatic intracranial hemorrhage was not different between the two groups (3.9% vs 3.5%, P=0.75, adjusted OR 0.94 (95% CI 0.23 to 3.88)).

CONCLUSION

Poor reperfusion after EVT was associated with worse outcomes than best medical management, although no difference in symptomatic intracranial hemorrhage was seen. These results emphasize the need for additional efforts to further improve technical EVT success rates.

Incidence and outcome of perforations during medium vessel occlusion compared with large vessel occlusion thrombectomy

BACKGROUND

Vessel perforation during thrombectomy is a severe complication and is hypothesized to be more frequent during medium vessel occlusion (MeVO) thrombectomy. The aim of this study was to compare the incidence and outcome of patients with perforation during MeVO and large vessel occlusion (LVO) thrombectomy and to report on the procedural steps that led to perforation.

METHODS

In this multicenter retrospective cohort study, data of consecutive patients with vessel perforation during thrombectomy between January 1, 2015 and September 30, 2022 were collected. The primary outcomes were independent functional outcome (ie, modified Rankin Scale 0-2) and all-cause mortality at 90 days. Binomial test, chi-squared test and t-test for unpaired samples were used for statistical analysis.

RESULTS

During 25 769 thrombectomies (5124 MeVO, 20 645 LVO) in 25 stroke centers, perforation occurred in 335 patients (1.3%; mean age 72 years, 62% female). Perforation occurred more often in MeVO thrombectomy (2.4%) than in LVO thrombectomy (1.0%, p<0.001). More MeVO than LVO patients with perforation achieved functional independence at 3 months (25.7% vs 10.9%, p=0.001). All-cause mortality did not differ between groups (overall 51.6%). Navigation beyond the occlusion and retraction of stent retriever/aspiration catheter were the two most common procedural steps that led to perforation.

CONCLUSIONS

In our cohort, perforation was approximately twice as frequent in MeVO than in LVO thrombectomy. Efforts to optimize the procedure may focus on navigation beyond the occlusion site and retraction of stent retriever/aspiration catheter. Further research is necessary in order to identify thrombectomy candidates at high risk of intraprocedural perforation and to provide data on the effectiveness of endovascular countermeasures.

Reducing the global burden of cerebral venous thrombosis: An international research agenda

BACKGROUND

Due to the rarity of cerebral venous thrombosis (CVT), performing high-quality scientific research in this field is challenging. Providing answers to unresolved research questions will improve prevention, diagnosis, and treatment, and ultimately translate to a better outcome of patients with CVT. We present an international research agenda, in which the most important research questions in the field of CVT are prioritized.

AIMS

This research agenda has three distinct goals: (1) to provide inspiration and focus to research on CVT for the coming years, (2) to reinforce international collaboration, and (3) to facilitate the acquisition of research funding.

SUMMARY OF REVIEW

This international research agenda is the result of a research summit organized by the International Cerebral Venous Thrombosis Consortium in Amsterdam, the Netherlands, in June 2023. The summit brought together 45 participants from 15 countries including clinical researchers from various disciplines, patients who previously suffered from CVT, and delegates from industry and non-profit funding organizations. The research agenda is categorized into six pre-specified themes: (1) epidemiology and clinical features, (2) life after CVT, (3) neuroimaging and diagnosis, (4) pathophysiology, (5) medical treatment, and (6) endovascular treatment. For each theme, we present two to four research questions, followed by a brief substantiation per question. The research questions were prioritized by the participants of the summit through consensus discussion.

CONCLUSIONS

This international research agenda provides an overview of the most burning research questions on CVT. Answering these questions will advance our understanding and management of CVT, which will ultimately lead to improved outcomes for CVT patients worldwide.

Incidence and clinical outcomes of perforations during mechanical thrombectomy for medium vessel occlusion in acute ischemic stroke: A retrospective, multicenter, and multinational study

BACKGROUND

Mechanical thrombectomy (MT) has revolutionized the treatment of acute ischemic stroke (AIS) due to large vessel occlusion (LVO), but its efficacy and safety in medium vessel occlusion (MeVO) remain less explored. This multicenter, retrospective study aims to investigate the incidence and clinical outcomes of vessel perforations (confirmed by extravasation during an angiographic series) during MT for AIS caused by MeVO.

METHODS

Data were collected from 37 academic centers across North America, Asia, and Europe between September 2017 and July 2021. A total of 1373 AIS patients with MeVO underwent MT. Baseline characteristics, procedural details, and clinical outcomes were analyzed.

RESULTS

The incidence of vessel perforation was 4.8% (66/1373). Notably, our analysis indicates variations in perforation rates across different arterial segments: 8.9% in M3 segments, 4.3% in M2 segments, and 8.3% in A2 segments (p = 0.612). Patients with perforation had significantly worse outcomes, with lower rates of favorable angiographic outcomes (TICI 2c-3: 23% vs 58.9%, p < 0.001; TICI 2b-3: 56.5% vs 88.3%, p < 0.001). Functional outcomes were also worse in the perforation group (mRS 0-1 at 3 months: 22.7% vs 36.6%, p = 0.031; mRS 0-2 at 3 months: 28.8% vs 53.9%, p < 0.001). Mortality was higher in the perforation group (30.3% vs 16.8%, p = 0.008).

CONCLUSION

This study reveals that while the occurrence of vessel perforation in MT for AIS due to MeVO is relatively rare, it is associated with poor functional outcomes and higher mortality. The findings highlight the need for increased caution and specialized training in performing MT for MeVO. Further prospective research is required for risk mitigation strategies.

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.

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.

Automated Intracranial Clot Detection: A Promising Tool for Vascular Occlusion Detection in Non-Enhanced CT

(1) Background: to test the diagnostic performance of a fully convolutional neural network-based software prototype for clot detection in intracranial arteries using non-enhanced computed tomography (NECT) imaging data. (2) Methods: we retrospectively identified 85 patients with stroke imaging and one intracranial vessel occlusion. An automated clot detection prototype computed clot location, clot length, and clot volume in NECT scans. Clot detection rates were compared to the visual assessment of the hyperdense artery sign by two neuroradiologists. CT angiography (CTA) was used as the ground truth. Additionally, NIHSS, ASPECTS, type of therapy, and TOAST were registered to assess the relationship between clinical parameters, image results, and chosen therapy. (3) Results: the overall detection rate of the software was 66%, while the human readers had lower rates of 46% and 24%, respectively. Clot detection rates of the automated software were best in the proximal middle cerebral artery (MCA) and the intracranial carotid artery (ICA) with 88-92% followed by the more distal MCA and basilar artery with 67-69%. There was a high correlation between greater clot length and interventional thrombectomy and between smaller clot length and rather conservative treatment. (4) Conclusions: the automated clot detection prototype has the potential to detect intracranial arterial thromboembolism in NECT images, particularly in the ICA and MCA. Thus, it could support radiologists in emergency settings to speed up the diagnosis of acute ischemic stroke, especially in settings where CTA is not available.

Thrombectomy of Mild Stroke : An Analysis of the Nationwide Registry of the German Society for Neuroradiology

PURPOSE

Whether patients presenting with mild stroke (NIHSS at admission < 6) should be treated with mechanical thrombectomy (MT) is the subject of an ongoing debate. This retrospective study based on large-scale clinical data aims to identify factors associated with favorable outcome (FO) in patients with mild stroke.

METHODS

A total of 761 patients with mild stroke enrolled between 1 January 2020 and 31 December 2020 in the Quality Registry of the German Society for Neuroradiology were analyzed. The FO was defined as stable or improved NIHSS at discharge vs. admission. Descriptive statistics and multivariable logistic regression analyses were performed to identify factors associated with FO. Furthermore, a subgroup analysis of mild stroke based on distal vessel occlusion was conducted.

RESULTS

In this study 610 patients had FO with a median NIHSS at discharge of 1 (interquartile range, IQR, 0-2) and 151 had an unfavorable outcome (UO) with median NIHSS at discharge of 10 (IQR 13). Patients with FO had a slightly higher NIHSS at admission (4 vs. 3, p < 0.001), lower mTICI 0 (2.7% vs. 14.2%, p < 0.001), higher mTICI 3 (61.3% vs. 34.5%, p < 0.001) and a lower number of passes (1 vs. 2, p < 0.001). No statistically significant difference was observed for MT-related adverse events. Multivariable logistic regression suggested that NIHSS at admission (adjusted odds ratio (aOR) = 1.28, 95% confidence interval (CI) = 1.10-1.48), mTICI 2b (aOR = 5.44, CI = 2.06-15.03), mTICI 2c (aOR = 10.81, CI = 3.65-34.07) and mTICI 3 (aOR = 11.56, CI = 4.49-31.10) as well as number of passes (aOR 0.76, CI = 0.66-0.88) were significantly associated with FO. No MT-related adverse events were observed for distal vessel occlusions.

CONCLUSION

The FO in patients with mild stroke undergoing MT was associated with successful recanalization. No significant differences between patients with FO and UO were found for MT-related adverse events, suggesting that MT complications have no significant effects on the outcome of these patients. MT might improve the prognosis also in patients with mild stroke based on distal vessel occlusions without significantly increasing the risk of adverse events.

Thrombectomy in ischemic stroke patients with alberta stroke program early computed tomography score 4-5 and 0-3: Factors associated with favorable outcome

OBJECTIVES

Recently published results of the ANGEL-ASPECT and SELECT2 trials suggest that stroke patients presenting with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) benefit from mechanical thrombectomy. Purpose of this retrospective study was to identify factors that are associated with a favorable outcome in patients with low ASPECTS of 4-5 and 0-3 undergoing mechanical thrombectomy.

MATERIAL AND METHODS

All patients reported in the quality registry of the German Society for Neuroradiology that were treated between 2018 and 2020 were analyzed. Favorable outcome was defined as a National Institute of Health Stroke Scale (NIHSS) score of less than 9 at dismissal. Successful recanalization was defined as Thrombolysis in Cerebral Infarction (mTICI) ≥ 2b. Multivariable logistic regression analyses were performed to assess the association of baseline and treatment variables with favorable outcome.

RESULTS

621 patients were included in the analysis, thereof 495 with ASPECTS 4-5 and 126 with ASPECTS 0-3. In patients with ASPECTS 4-5patients with favorable outcome had less severe neurological symptoms at admission with median NIHSS of 15 vs. 18 (p<0.001), had less often wake-up strokes (44% vs. 81%, p<0.001), received more often iv-lysis (37% vs. 30%, p<0.001), had more often conscious sedation (29% vs. 16%, p<0.001), had a higher rate of successful recanalization (94% vs. 66% and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.89-0.91) and successful recanalization (aOR 3.96, CI 2-8.56) were associated with favorable outcome. For ASPECTS 0-3, patients with favorable outcome had lower median NIHSS at admission (16 vs. 18 (p<0.001), lower number of passes (1 vs. 3, p=0.003) and a higher rate of successful recanalization (94% vs. 66%, p<0.001) and lower times from groin puncture to recanalization. In multivariate regression analysis lower NIHSS at admission (aOR 0.87, CI 0.81-0.94) and successful recanalization, (aOR 11.19, CI 3.19-55.53), were associated with favorable outcome.

CONCLUSION

Full recanalization with low groin punction to recanalization times and low number of passes were associated with favorable outcome in patients with low ASPECTS.

Complete recanalization predicts favorable outcome in patients with distal M2-M3 middle cerebral artery occlusions following endovascular thrombectomy

BACKGROUND

- scanty articles illustrate the prognostic factors for favorable outcome after endovascular thrombectomy (EVT) in distal vessel occlusion (DMVO). Moreover, the current literature is diversified; conglomerating both primary, secondary, and anterior, posterior circulations embolic strokes in the same shell.

PURPOSE

to identify the association between complete reperfusion and favorable outcome following EVT for DMVO in the middle cerebral artery (MCA) territory.

METHODS

-we performed a retrospective analysis of prospectively maintained EVT registries at two comprehensive stroke centers between January 2015 and December 2019 for consecutive stroke patients with MCA-DMVO. DMVO was defined as an occlusion of distal M2 and M3 segments of the MCA. Only patients with primary isolated occlusions were included. A multivariate logistic regression was utilized to identify clinical and procedural-related factors associated with the 90-day favorable clinical outcome [defined as modified Rankin score (mRS) 0-2] after EVT.

RESULTS

-Out of 1823 within the registries; 66 patients (median age was 72 (60-78) and 59% were males) with primary isolated DMVO of the MCA were eligible for inclusion in the current study. Complete reperfusion was achieved in 56% (37/66) of the patients with no difference among the reperfusion strategies while the favorable outcome was observed in 68% (45/66). In the multivariate analysis, final complete reperfusion [modified Thrombolysis In Cerebral Infarction (mTICI) score 2c-3] was significantly associated with favorable outcome [aOR=7.69; (95% CI 1.73-34.17); p=.01], while higher baseline NIHSS score [aOR=0.82; (95% CI 0.69-0.98); p=.03] and increased imaging to puncture interval [aOR=0.99; (95% CI 0.98, 1.00); p=.01] decreased the probability of the favorable outcome.

CONCLUSION

according to our results, complete reperfusion was the most significant predictor of the favorable outcome, while higher baseline NIHSS and longer imaging to puncture interval decreased the probability of the favorable outcome.

Machine learning based outcome prediction of large vessel occlusion of the anterior circulation prior to thrombectomy in patients with wake-up stroke

PURPOSE

Outcome prediction of large vessel occlusion of the anterior circulation in patients with wake-up stroke is important to identify patients that will benefit from thrombectomy. Currently, mismatch concepts that require MRI or CT-Perfusion (CTP) are recommended to identify these patients. We evaluated machine learning algorithms in their ability to discriminate between patients with favorable (defined as a modified Rankin Scale (mRS) score of 0-2) and unfavorable (mRS 3-6) outcome and between patients with poor (mRS5-6) and non-poor (mRS 0-4) outcome.

METHODS

Data of 8395 patients that were treated between 2018 and 2020 from the nationwide registry of the German Society for Neuroradiology was retrospectively analyzed. Five models were trained with clinical variables and Alberta Stroke Program Early CT Score (ASPECTS). The model with the highest accuracy was validated with a test dataset with known stroke onset and with a test dataset that consisted only of wake-up strokes.

RESULTS

2419 patients showed poor and 3310 patients showed favorable outcome. The best performing Random Forest model achieved a sensitivity of 0.65, a specificity of 0.81 and an AUC of 0.79 on the test dataset of patients with wake-up stroke in the classification analysis between favorable and unfavorable outcome and a sensitivity of 0.42, a specificity of 0.83 and an AUC of 0.72 in the classification analysis between poor and non-poor outcome.

CONCLUSION

Machine learning algorithms have the potential to aid in the decision making for thrombectomy in patients with wake-up stroke especially in hospitals, where emergency CTP or MRI imaging is not available.

Recombinant pregnancy-specific glycoprotein-1-Fc reduces functional deficit in a mouse model of permanent brain ischaemia

Background

The well-characterised role of the immune system in acute ischaemic stroke has prompted the search for immunomodulatory therapies. Pregnancy-specific glycoproteins (PSGs) are a group of proteins synthesised by placental trophoblasts which show immunomodulatory properties. The aim of this study was to determine whether a proposed PSG1-based therapeutic enhanced recovery in a mouse model of brain ischaemia and to explore possible immunomodulatory effects.

Methods

Mice underwent permanent electrocoagulation of the left middle cerebral artery (pMCAO). They received saline (n = 20) or recombinant pregnancy-specific glycoprotein-1-alpha “fused” to the Fc domain of IgG1 (rPSG1-Fc) (100 μg) (n = 22) at 1 h post-ischaemia. At 3 and 5 days post-ischaemia, neurobehavioural recovery was assessed by the grid-walking test. At 5 days post-ischaemia, lesion size was determined by NeuN staining. Peripheral T cell populations were quantified via flow cytometry. Immunohistochemistry was used to quantify ICAM-1 expression and FoxP3+ cell infiltration in the ischaemic brain. Immunofluorescence was employed to determine microglial activation status via Iba-1 staining.

Results: rPSG1-Fc significantly enhanced performance in the grid-walking test at 3 and 5 days post-ischaemia. No effect on infarct size was observed. A significant increase in circulating CD4⁺ FoxP3+ cells and brain-infiltrating FoxP3+ cells was noted in rPSG1-Fc-treated mice. Among CD4⁺ cells, rPSG1-Fc enhanced the expression of IL-10 in spleen, blood, draining lymph nodes, and non-draining lymph nodes, while downregulating IFN-γ and IL-17 in spleen and blood. A similar cytokine expression pattern was observed in CD8⁺ cells. rPSG1-Fc reduced activated microglia in the infarct core.

Conclusion

The administration of rPSG1-Fc improved functional recovery in post-ischaemic mice without impacting infarct size. Improved outcome was associated with a modulation of the cytokine-secreting phenotype of CD4⁺ and CD8⁺ T cells towards a more regulatory phenotype, as well as reduced activation of microglia. This establishes proof-of-concept of rPSG1-Fc as a potential stroke immunotherapy.

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rPSG1-Fc enhances functional recovery in a mouse model of permanent brain ischaemia.

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rPSG1-Fc increases circulating CD4⁺ FoxP3+ cells and brain-infiltrating FoxP3+ cells.

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rPSG1-Fc increases the expression of IL-10 among CD4⁺ cells in spleen, blood, and lymph nodes.

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

In-vitro neurovascular models of large vessel occlusions (LVOs) causing acute ischemic stroke (AIS) are used extensively for pre-clinical testing of new treatment devices. They enable physicians and engineers to examine device performance and the response of the occlusion to further advance design solutions for current unmet clinical needs. These models also enable physicians to train on basic skills, to try out new devices and new procedural approaches, and for the stroke team to practice workflows together in the comfort of a controlled environment in a non-clinical setting. Removal of the occlusive clot in its entirety is the primary goal of the endovascular treatment of LVOs via mechanical thrombectomy (MT) and the medical treatment via thrombolysis. In MT, recanalization after just one pass is associated with better clinical outcomes than procedures that take multiple passes to achieve the same level of recanalization, commonly known as first pass effect (FPE). To achieve this, physicians and engineers are continually investigating new devices and treatment approaches. To distinguish between treatment devices in the pre-clinical setting, test models must also be optimized and expanded become more nuanced and to represent challenging patient cohorts that could be improved through new technology or better techniques. The aim of this paper is to provide a perspective review of the recent advancements in the in-vitro modeling of stroke and to outline how these models need to advance further in future. This review provides an overview of the various in-vitro models used for the modeling of AIS and compares the advantages and limitations of each. In-vitro models remain an extremely useful tool in the evaluation and design of treatment devices, and great strides have been made to improve replication of physiological conditions. However, further advancement is still required to represent the expanding indications for thrombectomy and thrombolysis, and the generation of new thrombectomy devices, to ensure that smaller treatment effects are captured.

Childhood stroke

Stroke is an important cause of neurological morbidity in children; most survivors have permanent neurological deficits that affect the remainder of their life. Stroke in childhood, the focus of this Primer, is distinguished from perinatal stroke, defined as stroke before 29 days of age, because of its unique pathogenesis reflecting the maternal-fetal unit. Although approximately 15% of strokes in adults are haemorrhagic, half of incident strokes in children are haemorrhagic and half are ischaemic. The causes of childhood stroke are distinct from those in adults. Urgent brain imaging is essential to confirm the stroke diagnosis and guide decisions about hyperacute therapies. Secondary stroke prevention strongly depends on the underlying aetiology. While the past decade has seen substantial advances in paediatric stroke research, the quality of evidence for interventions, such as the rapid reperfusion therapies that have revolutionized arterial ischaemic stroke care in adults, remains low. Substantial time delays in diagnosis and treatment continue to challenge best possible care. Effective primary stroke prevention strategies in children with sickle cell disease represent a major success, yet barriers to implementation persist. The multidisciplinary members of the International Pediatric Stroke Organization are coordinating global efforts to tackle these challenges and improve the outcomes in children with cerebrovascular disease.

Distribution of Diagnoses and Clinical and Imaging Characteristics in 1,322 Consecutive Suspected Stroke Patients

Background: Endovascular thrombectomy (EVT) has become the standard of care for large-vessel occlusion strokes, but several barriers for implementing an optimal organization of stroke management remain. Major issues include the lack of reliable data on the percentage of stroke patients potentially eligible for EVT especially in times of expanding indications for EVT. Our aim was therefore to study the frequencies of possible EVT-eligible patients such as patients with medium-vessel occlusions, patients with low Alberta Stroke Program Early Computed Tomography Scores (ASPECTS), patients presenting in an extended time window after onset of symptoms, and patients with mild symptoms at presentation (National Institutes of Health Stroke Scale, NIHSS ≤ 5). We also give detailed imaging and clinical information about the patients presenting with intracranial hemorrhage and other ischemic stroke mimics stratified by symptoms at presentation.

Methods: Cohort study of all consecutive patients with suspected acute stroke presenting to a tertiary care center in Germany between September 1, 2016, and August 31, 2017. Baseline and follow-up clinical and imaging characteristics were collected from patients' medical charts.

Results: Of 1,322 patients with a suspected acute stroke, 592 (44.8%) had ischemic strokes, 221 (16.7%) had hemorrhagic strokes, 190 (10.9%) had transient ischemic attacks (TIAs), and 319 (24.1%) were classified as stroke mimics. Stroke severity was mild (NIHSS ≤ 5) in 866 (65.5%) patients; 15.7% of the patients with an occlusion of the anterior circulation had an ASPECTS ≤ 5, 17.4% of the patients with an ischemic stroke had distal vessel occlusions, and 49% of the patients presented later than 6 h after onset of symptoms.

Conclusion: Our results help to plan resources in thrombectomy-capable centers in times of expanding indications for EVT where resources will have to be adjusted to patients with low-NIHSS, low-ASPECTS, and distal occlusions, and patients presenting in the extended time window, which may altogether account for an additional 20% of all ischemic stroke patients.