Number needed to treat to benefit and to harm for intravenous tissue plasminogen activator therapy in the 3- to 4.5-hour window: joint outcome table analysis of the ECASS 3 trial

Efficacy and Safety of Recombinant Human Prourokinase in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: To evaluate the safety and efficacy of recombinant human prourokinase (rhPro-UK) administered via intravenous (IV) and intra-arterial (IA) routes in acute ischemic stroke (AIS) patients compared with standard treatments. Methods: A comprehensive search was conducted in accordance with PRISMA guidelines across Scopus, Web of Science, and PubMed until 11 December 2024. Randomized controlled trials (RCTs) assessing rhPro-UK's efficacy and safety were included. Outcomes included the modified Rankin Scale (mRS), the National Institutes of Health Stroke Scale (NIHSS), mortality, and adverse events (AEs). Data analysis used risk difference (RD) with 95% confidence intervals (CIs). Results: Six RCTs (n = 3993) met the inclusion criteria. IV rhPro-UK showed comparable efficacy to the comparator for the mRS 0-1 at 90 days (RD: 0.00, 95% CI: [-0.04, 0.04]) and the mRS 0-2 (RD: -0.01, 95% CI: [-0.03, 0.01], P = 0.23). IA rhPro-UK significantly improved the mRS 0-1 (RD: 0.13, 95% CI: [0.01, 0.26], P = 0.04). The NIHSS reduction was significant for IV rhPro-UK (MD: -0.83, 95% [CI: -1.36, -0.29]). IV rhPro-UK did not significantly reduce the risk of systemic bleeding (RD: -0.10, 95% CI: [-0.24, 0.03], P = 0.12), serious AEs (RD: -0.01, 95% CI: [-0.04, 0.02], P = 0.53), or mortality (RD: 0.01, 95% CI: -0.01, 0.02). IA rhPro-UK significantly increased hemorrhage with neurological deterioration (RD: 0.08, 95% CI: [0.01, 0.14], P = 0.02). Conclusions: IV rhPro-UK provides non-inferior efficacy to both alteplase and standard care with a better safety profile at 35 mg, while IA rhPro-UK enhances functional outcomes in middle cerebral artery occlusions, albeit with safety concerns. Further trials are needed to confirm long-term outcomes, optimal dosing, and broader applicability.

[Task Force Dyspnoe unit (DU)]

Acute dyspnoea is one of the most common internal medicine symptoms in the emergency department. It arises from an acute illness or from the exacerbation of a chronic illness. Symptom-related emergency structures and corresponding structural guidelines already exist in the stroke and chest pain units for dealing with the leading symptoms of acute stroke and acute chest pain. These are lacking in Germany for the key symptom of dyspnoea, although the benefits of these structures have already been proven in other countries. The German Society for Pneumology and Respiratory Medicine (DGP) has now set up a task force together with the Association of Pneumology Clinics (VPK), in order to deal with the topic and develop appropriate structural guidelines for such "dyspnoea units" in Germany. At the end of the process, the certification of such units at German hospitals is optional.

Noninvasive imaging biomarker reveals invisible microscopic variation in acute ischaemic stroke (≤ 24 h): a multicentre retrospective study

To develop and validate non-contrast computed tomography (NCCT)-based radiomics method combines machine learning (ML) to investigate invisible microscopic acute ischaemic stroke (AIS) lesions. We retrospectively analyzed 1122 patients from August 2015 to July 2022, whose were later confirmed AIS by diffusion-weighted imaging (DWI). However, receiving a negative result was reported by radiologists according to the NCCT images. Patients in five institutions (n = 592) were combined to generate training and internal validation sets, remaining in three institutions as external validation sets (n = 204, 53 and 273). Through a series of procedures: head alignment, co-registration of NCCT and DWI, the volume of interest delineation and feature extraction. Multiple ML models (random forest, RF; support vector machine, SVM; logistic regression, LR; multilayer perceptron, MLP) were used to discriminate microscopic AIS and non-AIS. Among 1122 patients included (760 men [67.7%]; median [range] age, 64 [21-96] years). After least absolute shrinkage and selection operator (LASSO) algorithm, 44 optimal features were remained. The radiomics combined ML models were yielded similar mean areas under the receiver operating characteristic curve of 0.808 (95% CI 0.754 to 0.861) for RF, 0.802 (95% CI 0.748 to 0.856) for radial basis kernel function-based SVM, 0.792 (95% CI 0.737 to 0.847) for MLP, 0.792 (95% CI 0.736 to 0.848) for Linear-SVM and 0.787 (95% CI 0.730 to 0.844) for LR, respectively. Combining radiomics with ML models can be an efficient, noninvasive, economical, and reliable technique for evaluating invisible microscopic AIS on NCCT and assisting radiologists to make clinical decisions.

Endovascular therapy for acute vertebrobasilar occlusion (VERITAS): a systematic review and individual patient data meta-analysis

BACKGROUND

Trials of endovascular therapy for basilar artery occlusion, including vertebral occlusion extending into the basilar artery, have shown inconsistent results. We aimed to pool data to estimate safety and efficacy and to explore the benefit across pre-specified subgroups through individual patient data meta-analysis.

METHODS

VERITAS was a systematic review and meta-analysis that pooled patient-level data from trials that recruited patients with vertebrobasilar ischaemic stroke who were randomly assigned to treatment with either endovascular therapy or standard medical treatment alone. We included studies done between Jan 1, 2010, and Sept 1, 2023. The primary outcome was 90-day favourable functional status (modified Rankin Scale [mRS] score 0-3, with a score of 3 indicating moderate disability). Safety outcomes were symptomatic intracranial haemorrhage and 90-day mortality.

FINDINGS

We screened 934 titles and abstracts. Of these, seven (<1%) full texts were screened. We included four trials (ATTENTION, BAOCHE, BASICS, and BEST). The pooled data included 988 patients (556 [56%] in the intervention groups and 432 [44%] in the control groups; median age 67 years [IQR 58-74]; 686 (69%) were male and 302 (31%) were female). 904 (91%) patients were randomly assigned within 12 h of estimated stroke onset. Three RCTs were done in a Chinese population and one included European and Brazilian patients. The proportion of patients achieving favourable functional status was higher in the endovascular therapy than control group (90-day mRS score 0-3 in 251 [45%] participants vs 128 [30%]; adjusted common odds ratio 2·41 [95% CI 1·78-3·26]; p<0·0001). Endovascular therapy led to an increase in functional independence (mRS score 0-2 in 194 [35%] participants vs 89 [21%]; 2·52 [1·82-3·48]; p<0·0001) as well as a reduction in both the degree of overall disability (2·09 [1·61-2·71]; p<0·0001) and mortality (198 [36%] of 556 patients vs 196 [45%] of 432; 0·60 [0·45-0·80]; p<0·0001) at 90 days, despite higher rates of symptomatic intracranial haemorrhage (30 [5%] of 548 vs two [<1%] of 413; 11·98 [2·82-50·81]; p<0·0001). Heterogeneity of treatment effect was noted for baseline stroke severity (uncertain effect in baseline National Institutes of Health Stroke Scale <10) and occlusion site (greater benefit with more proximal occlusions) but not across subgroups defined by age, sex, baseline posterior circulation Alberta Stroke Program Early CT Score, presence of atrial fibrillation or intracranial atherosclerotic disease, and time from onset to imaging.

INTERPRETATION

VERITAS supports the robust benefit of endovascular therapy in patients with vertebrobasilar artery occlusion with moderate to severe symptoms, with approximately 2·5-times increased likelihood of achieving a favourable functional outcome. Despite a significant increase in symptomatic intracranial haemorrhage risk, endovascular therapy for vertebrobasilar artery occlusion was associated with a significant reduction in both overall disability and mortality. Although the benefit of endovascular therapy remains uncertain for patients vertebrobasilar artery occlusion presenting with mild stroke severity and extensive infarcts on neuroimaging, we found a significant clinical benefit across a range of patients with vertebrobasilar artery occlusion.

FUNDING

None.

Stroke severity modified the effect of chronic atrial fibrillation on the outcome of thrombolytic therapy

There is conflicting information regarding the impact of chronic atrial fibrillation (AF) on the outcomes of thrombolyzed patients with stroke. This study was designed to identify high-risk patients with chronic AF who had undergone thrombolysis treatment and to explore whether the baseline National Institutes of Health Stroke Scale (NIHSS) could be used to distinguish poor clinical outcomes in thrombolyzed patients. A total of 164 acute ischemic stroke patients with chronic AF were enrolled in this study. The patients were categorized as having poor or favorable outcomes. A favorable 90-day outcome was defined as a modified Rankin Scale (mRS) score ≤2. Our study showed that the baseline NIHSS score of patients with poor functional recovery (mRS >2) was significantly higher than that of patients with favorable outcomes (median 16 vs 12). Receiver operating characteristic (ROC) curve analysis of mRS score showed that a baseline NIHSS score of 14 was the optimal threshold for predicting unfavorable outcomes in patients with chronic AF. Multivariate logistic regression analysis showed that baseline NIHSS score >14 was independently associated with poor outcomes (odds ratio = 4.182, 95% confidence interval 2.092-8.361). Our study showed that stroke severity modified the effect of chronic AF on the outcome of thrombolytic therapy. The approach of stratifying stroke severity may be used to evaluate treatment strategies for decision making in intravenous thrombolytic therapy for acute stroke with chronic AF.

Rapid Thrombolysis Protocol: Results from a Before-and-after Study

Objective

Intravenous thrombolysis within 4.5 hours from time of onset has proven benefit in stroke. Universal standard for the door-to-needle (DTN) time is within 60 minutes from the time of arrival of patients to the emergency department. Our rapid thrombolysis protocol (RTPr) was developed with an aim to reduce the DTN time to a minimum by modifying our stroke post-intervention processes.

Materials and methods

This before-and-after study was conducted at a single center on patients who received intravenous thrombolysis in the emergency department. Consecutive patients who were thrombolysed using our RTPr (post-intervention group) were compared to the pre-intervention group who were thrombolysed before the implementation of the protocol. The primary outcomes were DTN time, time to recovery, and modified ranking score (mRS) on discharge. Secondary outcomes were mortality, symptomatic intracerebral hemorrhage, and hospital and intensive care unit length of stay.

Results

Seventy-four patients were enrolled in each group. Mean DTN time in pre- and post-intervention group was 56.15 minutes (95% CI 49.98–62.31) and 34.91 minutes (95% CI 29.64–40.17) (p <0.001), respectively. In pre-intervention and post-intervention groups, 43.24% (95% CI 32.57–54.59) and 41.89% (95% CI 31.32–53.26) patients, respectively, showed neurological recovery in 24 hours. About 36.49% (95% CI 26.44–47.87) in pre-intervention group and 54.05% (95% CI 42.78–64.93) in post-intervention group had discharge mRS 0–2.

Conclusion

The RTPr can be adapted by clinicians and hospitals to bring down the DTN times and improve outcomes for stroke patients.

How to cite this article

Verma A, Sarda S, Jaiswal S, Batra A, Haldar M, Sheikh WR, et al. Rapid Thrombolysis Protocol: Results from a Before-and-after Study. Indian J Crit Care Med 2022;26(5):549–554.

Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis

BACKGROUND

Trials examining the benefit of thrombectomy in anterior circulation proximal large vessel occlusion stroke have enrolled patients considered to have salvageable brain tissue, who were randomly assigned beyond 6 h and (depending on study protocol) up to 24 h from time last seen well. We aimed to estimate the benefit of thrombectomy overall and in prespecified subgroups through individual patient data meta-analysis.

METHODS

We did a systematic review and individual patient data meta-analysis between Jan 1, 2010, and March 1, 2021, of randomised controlled trials of endovascular stroke therapy. In the Analysis Of Pooled Data From Randomized Studies Of Thrombectomy More Than 6 Hours After Last Known Well (AURORA) collaboration, the primary outcome was disability on the modified Rankin Scale (mRS) at 90 days, analysed by ordinal logistic regression. Key safety outcomes were symptomatic intracerebral haemorrhage and mortality within 90 days.

FINDINGS

Patient level data from 505 individuals (n=266 intervention, n=239 control; mean age 68·6 years [SD 13·7], 259 [51·3%] women) were included from six trials that met inclusion criteria of 17 screened published randomised trials. Primary outcome analysis showed a benefit of thrombectomy with an unadjusted common odds ratio (OR) of 2·42 (95% CI 1·76-3·33; p<0·0001) and an adjusted common OR (for age, gender, baseline stroke severity, extent of infarction on baseline head CT, and time from onset to random assignment) of 2·54 (1·83-3·54; p<0·0001). Thrombectomy was associated with higher rates of independence in activities of daily living (mRS 0-2) than best medical therapy alone (122 [45·9%] of 266 vs 46 [19·3%] of 238; p<0·0001). No significant difference between intervention and control groups was found when analysing either 90-day mortality (44 [16·5%] of 266 vs 46 [19·3%] of 238) or symptomatic intracerebral haemorrhage (14 [5·3%] of 266 vs eight [3·3%] of 239). No heterogeneity of treatment effect was noted across subgroups defined by age, gender, baseline stroke severity, vessel occlusion site, baseline Alberta Stroke Program Early CT Score, and mode of presentation; treatment effect was stronger in patients randomly assigned within 12-24 h (common OR 5·86 [95% CI 3·14-10·94]) than those randomly assigned within 6-12 h (1·76 [1·18-2·62]; p_interaction=0·0087).

INTERPRETATION

These findings strengthen the evidence for benefit of endovascular thrombectomy in patients with evidence of reversible cerebral ischaemia across the 6-24 h time window and are relevant to clinical practice. Our findings suggest that in these patients, thrombectomy should not be withheld on the basis of mode of presentation or of the point in time of presentation within the 6-24 h time window.

FUNDING

Stryker Neurovascular.

Neuronal injuries in cerebral infarction and ischemic stroke: From mechanisms to treatment (Review)

Stroke is the leading cause of disabilities and cognitive deficits, accounting for 5.2% of all mortalities worldwide. Transient or permanent occlusion of cerebral vessels leads to ischemic strokes, which constitutes the majority of strokes. Ischemic strokes induce brain infarcts, along with cerebral tissue death and focal neuronal damage. The infarct size and neurological severity after ischemic stroke episodes depends on the time period since occurrence, the severity of ischemia, systemic blood pressure, vein systems and location of infarcts, amongst others. Ischemic stroke is a complex disease, and neuronal injuries after ischemic strokes have been the focus of current studies. The present review will provide a basic pathological background of ischemic stroke and cerebral infarcts. Moreover, the major mechanisms underlying ischemic stroke and neuronal injuries are summarized. This review will also briefly summarize some representative clinical trials and up-to-date treatments that have been applied to stroke and brain infarcts.

Off-label use of intravenous thrombolysis for acute ischemic stroke: a critical appraisal of randomized and real-world evidence

Intravenous thrombolysis (IVT) represents the only systemic reperfusion therapy able to reverse neurological deficit in patients with acute ischemic stroke (AIS). Despite its effectiveness in patients with or without large vessel occlusion, it can be offered only to a minority of them, because of the short therapeutic window and additional contraindications derived from stringent but arbitrary inclusion and exclusion criteria used in landmark randomized controlled clinical trials. Many absolute or relative contraindications lead to disparities between the official drug label and guidelines or expert recommendations. Based on recent advances in neuroimaging and evidence from cohort studies, off-label use of IVT is increasingly incorporated into the daily practice of many stroke centers. They relate to extension of therapeutic time windows, and expansion of indications in co-existing conditions originally listed in exclusion criteria, such as use of alternative thrombolytic agents, pre-treatment with antiplatelets, anticoagulants or low molecular weight heparins. In this narrative review, we summarize recent randomized and real-world data on the safety and efficacy of off-label use of IVT for AIS. We also make some practical recommendations to stroke physicians regarding the off-label use of thrombolytic agents in complex and uncommon presentations of AIS or other conditions mimicking acute cerebral ischemia. Finally, we provide guidance on the risks and benefits of IVT in numerous AIS subgroups, where equipoise exists and guidelines and treatment practices vary.

Endothelial S1P1 Signaling Counteracts Infarct Expansion in Ischemic Stroke

RATIONALE

Cerebrovascular function is critical for brain health, and endogenous vascular protective pathways may provide therapeutic targets for neurological disorders. S1P (Sphingosine 1-phosphate) signaling coordinates vascular functions in other organs, and S1P1 (S1P receptor-1) modulators including fingolimod show promise for the treatment of ischemic and hemorrhagic stroke. However, S1P1 also coordinates lymphocyte trafficking, and lymphocytes are currently viewed as the principal therapeutic target for S1P1 modulation in stroke.

OBJECTIVE

To address roles and mechanisms of engagement of endothelial cell S1P1 in the naive and ischemic brain and its potential as a target for cerebrovascular therapy.

METHODS AND RESULTS

Using spatial modulation of S1P provision and signaling, we demonstrate a critical vascular protective role for endothelial S1P1 in the mouse brain. With an S1P1 signaling reporter, we reveal that abluminal polarization shields S1P1 from circulating endogenous and synthetic ligands after maturation of the blood-neural barrier, restricting homeostatic signaling to a subset of arteriolar endothelial cells. S1P1 signaling sustains hallmark endothelial functions in the naive brain and expands during ischemia by engagement of cell-autonomous S1P provision. Disrupting this pathway by endothelial cell-selective deficiency in S1P production, export, or the S1P1 receptor substantially exacerbates brain injury in permanent and transient models of ischemic stroke. By contrast, profound lymphopenia induced by loss of lymphocyte S1P1 provides modest protection only in the context of reperfusion. In the ischemic brain, endothelial cell S1P1 supports blood-brain barrier function, microvascular patency, and the rerouting of blood to hypoperfused brain tissue through collateral anastomoses. Boosting these functions by supplemental pharmacological engagement of the endothelial receptor pool with a blood-brain barrier penetrating S1P1-selective agonist can further reduce cortical infarct expansion in a therapeutically relevant time frame and independent of reperfusion.

CONCLUSIONS

This study provides genetic evidence to support a pivotal role for the endothelium in maintaining perfusion and microvascular patency in the ischemic penumbra that is coordinated by S1P signaling and can be harnessed for neuroprotection with blood-brain barrier-penetrating S1P1 agonists.

Decision-Making Visual Aids for Late, Imaging-Guided Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Speedy decision-making is important for optimal outcomes from endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). Figural decision aids facilitate rapid review of treatment benefits and harms, but have not yet been developed for late-presenting patients selected for EVT based on multimodal computed tomography or magnetic resonance imaging.

METHODS

For combined pooled study-level randomized trial (DAWN and DEFUSE 3) data, as well as each trial singly, 100 person-icon arrays (Kuiper-Marshall personographs) were generated showing beneficial and adverse effects of EVT for patients with AIS and large vessel occlusion using automated (algorithmic) and expert-guided joint outcome table specification.

RESULTS

Among imaging-selected patients 6 to 24 hours from last known well, for the full 7-category modified Rankin Scale (mRS), EVT had number needed to treat to benefit 1.9 (interquartile range [IQR], 1.9 to 2.1) and number needed to harm 40.0 (IQR, 29.2 to 58.3). Visual displays of treatment effects among 100 patients showed that, with EVT: 52 patients have better disability outcome, including 32 more achieving functional independence (mRS 0 to 2); three patients have worse disability outcome, including one more experiencing severe disability or death (mRS 5 to 6), mediated by symptomatic intracranial hemorrhage and infarct in new territory. Similar features were present in person-icon figures based on a 6-level mRS (levels 5 and 6 combined) rather than 7-level mRS, and based on the DAWN trial alone and DEFUSE 3 trial alone.

CONCLUSIONS

Personograph visual decision aids are now available to rapidly educate patients, family, and healthcare providers regarding benefits and risks of EVT for late-presenting, imaging-selected AIS patients.

Impact of EMS bypass to endovascular capable hospitals: geospatial modeling analysis of the US STRATIS registry

BACKGROUND

Routing patients directly to endovascular capable centers (ECCs) would decrease time to mechanical thrombectomy (MT), but may delay intravenous thrombolysis (IVT).

OBJECTIVE

To study the clinical outcomes of patients with a stroke transferred directly to ECCs compared with those transferred to ECCs from non-endovascular capable centers (nECCs).

METHODS

Data from the STRATIS registry were analyzed to evaluate process and clinical outcomes under five routing policies: (1) transport to nearest nECC; (2) transport to STRATIS ECC over any distance or (3) within 20 miles; (4) transport to ideal ECC (iECC), over any distance or (5) within 20 miles.

RESULTS

Among 236 patients, 117 (49.6%) were transferred by ground, of whom 62 (53%) were transferred within 20 miles. Median MT start time was accelerated in all direct transport models. IVT start was prolonged with direct transport across all distances, but accelerated with direct transport to iECC ≤20 miles. With bypass limited to ≤20 miles, the median modeled EMS arrival to IVT interval decreased for both iECCs and ECCs (by 12 min and 6 min, respectively), and median EMS arrival to puncture time decreased by up to 94 min. In this cohort, no patient would have become ineligible for IVT. Bypass to iECC modeling under 20 miles showed a significant reduction in the level of disability at 3 months, with freedom from disability (modified Rankin Scale score 0-1) at 3 months increased by 12%.

CONCLUSIONS

Direct routing of patients with a large vessel occlusion to ECCs, especially when within 20 miles, may lead to better clinical outcomes by accelerating the start of MT without any delay of IVT.

CLINICAL TRIAL REGISTRATION NUMBER

http://www.clinicaltrials.gov. Unique identifier: NCT02239640.

Emergency management of stroke in the era of mechanical thrombectomy

Emergency management of stroke has been directed at the delivery of recombinant tissue plasminogen activator (tPA) in a timely fashion. Because of the many limitations attached to the delivery of tPA and the perceived benefits accrued to tPA, its use has been limited. Mechanical thrombectomy, a far superior therapy for the largest and most disabling strokes, large vessel occlusions (LVOs), has changed the way acute strokes are managed. Aside from the rush to deliver tPA, there is now a need to identify LVO and refer those patients with LVO to physicians and facilities capable of delivering urgent thrombectomy. Other parts of emergency department management of stroke are directed at identifying and mitigating risk factors for future strokes and at preventing further damage from occurring. We review here the most recent literature supporting these advances in stroke care and present a framework for understanding the role that emergency physicians play in acute stroke care.

Magnitude of Benefit of Combined Endovascular Thrombectomy and Intravenous Fibrinolysis in Large Vessel Occlusion Ischemic Stroke

Background and Purpose—

Quantifying the benefit magnitude of combined endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT) versus nonreperfusion care in patients with acute ischemic stroke caused by large vessel occlusion would aid organization of regional stroke care systems.

Methods—

NINDS rt-PA Study (National Institute for Neurological Disorders and Stroke Recombinant Tissue Plasminogen Activator) and SWIFT PRIME trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment) patients were matched for prognosis (based on age and National Institutes of Health Stroke Scale) and definite/likely anterior circulation large vessel occlusion (based on National Institutes of Health Stroke Scale total score and item pattern), using optimal inverse variance matching, to determine comparative outcomes with nonreperfusion care alone, IVT alone, and IVT+EVT.

Results—

Matching yielded 240 patients, including 80 each treated with nonreperfusion care, IVT alone, and IVT+EVT, with, respectively, mean age 67.1, 67.1, and 66.9 and presenting deficit severity (National Institutes of Health Stroke Scale) mean 15.8, 15.9, and 15.9. Outcomes at 3 months for IVT+EVT versus nonreperfusion care included freedom from disability (modified Rankin Scale score, 0–1) 48.1% versus 21.3%, P =0.0004; functional independence (modified Rankin Scale score, 0–2) 62.9% versus 32.6, P =0.0001; and reduced disability over all 7 modified Rankin Scale levels, common odds ratio 3.34, P <0.0001. Outcomes for IVT alone versus nonreperfusion care included: freedom from disability 30.0% versus 21.3%, P =0.28 and reduced disability over all 7 modified Rankin Scale levels, common odds ratio 1.14, P =0.65. Compared with nonreperfusion care, the number needed to treat with EVT+IVT for 1 more patient to have reduced disability was 1.8.

Conclusions—

Matched patient analysis across randomized trials provides evidence that the strategy of combined IVT and mechanical thrombectomy is a highly beneficial treatment strategy for acute ischemic stroke caused by large vessel occlusion patients. A reasonable effect magnitude estimate is that, among every 100 patients treated, combined IVT+EVT reperfusion therapy, compared with no reperfusion therapy, reduces long-term disability in 57, including conferring functional independence upon 30.

Time is Brain: The Future for Acute Ischemic Stroke Management is the Utilization of Steerable Microcatheters for Reperfusion

Stroke is the fifth leading cause of death in the United States and is one of the leading causes of patient disability. Treatments for intracranial intravascular damage as a result of stroke have evolved extensively over recent decades, as management has become increasingly innovative. Various prospective studies and years of data have refined the current guidelines for treatment of acute ischemic stroke (AIS) and also reflect on the novel interventions for stroke management. Nonetheless, AIS remains a difficult and multifactorial etiology of disease to treat. As physicians adapt evidence-based knowledge to their interventional management of patients with AIS, the accompanied use of intravascular devices, such as steerable microcatheters, reduces radiation and procedure time. Considering all of the applications for steerable microcatheters, the use of these devices for AIS interventions may be most necessary.

Constraint-induced movement therapy enhances angiogenesis and neurogenesis after cerebral ischemia/reperfusion

Constraint-induced movement therapy after cerebral ischemia stimulates axonal growth by decreasing expression levels of Nogo-A, RhoA, and Rho-associated kinase (ROCK) in the ischemic boundary zone. However, it remains unclear if there are any associations between the Nogo-A/RhoA/ROCK pathway and angiogenesis in adult rat brains in pathological processes such as ischemic stroke. In addition, it has not yet been reported whether constraint-induced movement therapy can promote angiogenesis in stroke in adult rats by overcoming Nogo-A/RhoA/ROCK signaling. Here, a stroke model was established by middle cerebral artery occlusion and reperfusion. Seven days after stroke, the following treatments were initiated and continued for 3 weeks: forced limb use in constraint-induced movement therapy rats (constraint-induced movement therapy group), intraperitoneal infusion of fasudil (a ROCK inhibitor) in fasudil rats (fasudil group), or lateral ventricular injection of NEP1–40 (a specific antagonist of the Nogo-66 receptor) in NEP1–40 rats (NEP1–40 group). Immunohistochemistry and western blot assay results showed that, at 2 weeks after middle cerebral artery occlusion, expression levels of RhoA and ROCK were lower in the ischemic boundary zone in rats treated with NEP1–40 compared with rats treated with ischemia/reperfusion or constraint-induced movement therapy alone. However, at 4 weeks after middle cerebral artery occlusion, expression levels of RhoA and ROCK in the ischemic boundary zone were markedly decreased in the NEP1–40 and constraint-induced movement therapy groups, but there was no difference between these two groups. Compared with the ischemia/reperfusion group, modified neurological severity scores and foot fault scores were lower and time taken to locate the platform was shorter in the constraint-induced movement therapy and fasudil groups at 4 weeks after middle cerebral artery occlusion, especially in the constraint-induced movement therapy group. Immunofluorescent staining demonstrated that fasudil promoted an immune response of nerve-regeneration-related markers (BrdU in combination with CD31 (platelet endothelial cell adhesion molecule), Nestin, doublecortin, NeuN, and glial fibrillary acidic protein) in the subventricular zone and ischemic boundary zone ipsilateral to the infarct. After 3 weeks of constraint-induced movement therapy, the number of regenerated nerve cells was noticeably increased, and was accompanied by an increased immune response of tight junctions (claudin-5), a pericyte marker (α-smooth muscle actin), and vascular endothelial growth factor receptor 2. Taken together, the results demonstrate that, compared with fasudil, constraint-induced movement therapy led to stronger angiogenesis and nerve regeneration ability and better nerve functional recovery at 4 weeks after cerebral ischemia/reperfusion. In addition, constraint-induced movement therapy has the same degree of inhibition of RhoA and ROCK as NEP1–40. Therefore, constraint-induced movement therapy promotes angiogenesis and neurogenesis after cerebral ischemia/reperfusion injury, at least in part by overcoming the Nogo-A/RhoA/ROCK signaling pathway. All protocols were approved by the Institutional Animal Care and Use Committee of China Medical University, China on December 9, 2015 (approval No. 2015PS326K).

Machine Learning in Acute Ischemic Stroke Neuroimaging

Machine Learning (ML) through pattern recognition algorithms is currently becoming an essential aid for the diagnosis, treatment, and prediction of complications and patient outcomes in a number of neurological diseases. The evaluation and treatment of Acute Ischemic Stroke (AIS) have experienced a significant advancement over the past few years, increasingly requiring the use of neuroimaging for decision-making. In this review, we offer an insight into the recent developments and applications of ML in neuroimaging focusing on acute ischemic stroke.

Intravenous Recombinant Tissue Plasminogen Activator and Ischemic Stroke: Focused Update of 2010 Clinical Practice Advisory From the American Academy of Emergency Medicine

BACKGROUND

Stroke treatment is a continuum that begins with the rapid identification of symptoms and treatment with transition to successful rehabilitation. Therapies for acute ischemic stroke (AIS) may vary based on anatomic location, interval from symptom onset, and coexisting health conditions. Successful therapy requires a seamless systematic approach with coordination from prehospital environment through acute management at medical facilities to disposition and long-term care of the patient. The emergency physician must balance the benefits and risks of alteplase recombinant tissue plasminogen activator (rtPA) for AIS management.

OBJECTIVE

We review the recent medical literature on the topic of AIS and assess intravenous rtPA for the following questions: 1) is there any applicable, new, high-quality evidence that the benefits of intravenous rtPA are justified in light of the harms associated with it, and 2) if so, does the evidence clarify which patients, if any, are most likely to benefit from the treatment.

METHODS

A MEDLINE literature search from January 2010 to October 2016 and limited to human studies written in English for articles with keywords of cerebrovascular accident and (thromboly* OR alteplase). Guideline statements and nonsystematic reviews were excluded. Studies targeting differences between specific populations (males vs. females) were excluded. Studies identified then underwent a structured review from which results could be evaluated.

RESULTS

Three hundred twenty-two papers on thrombolytic use were screened and nine appropriate articles were rigorously reviewed and recommendations given.

CONCLUSIONS

No new studies published between 2010 and 2016 meaningfully reduced uncertainty regarding our understanding of the benefits and harms of intravenous rtPA for AIS. Discussions regarding benefit and harm should occur for patients, and risk prediction scores may facilitate the conversation.

Targeting platelet receptors in thrombotic and thrombo-inflammatory disorders

Platelet activation at sites of vascular injury is critical for the formation of a hemostatic plug which limits excessive blood loss, but also represents a major pathomechanism of ischemic cardio- and cerebrovascular diseases. Although currently available antiplatelet therapies have proved beneficial in preventing the recurrence of vascular events, their adverse effects on primary hemostasis emphasize the necessity to identify and characterize novel pharmacological targets for platelet inhibition. Increasing experimental evidence has suggested that several major platelet surface receptors which regulate initial steps of platelet adhesion and activation may become promising new targets for anti-platelet drugs due to their involvement in thrombotic and thrombo-inflammatory signaling cascades.

This review summarizes recent developments in understanding the function of glycoprotein (GP)Ib, GPVI and the C-type lectin-like receptor 2 (CLEC-2) in hemostasis, arterial thrombosis and thrombo-inflammation and will discuss the suitability of the receptors as novel targets to treat these diseases in humans.

Visual Aids for Patient, Family, and Physician Decision Making About Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Rapid decision making optimizes outcomes from endovascular thrombectomy for acute cerebral ischemia. Visual displays facilitate swift review of potential outcomes and can accelerate decision processes.

METHODS

From patient-level, pooled randomized trial data, 100 person-icon arrays (Kuiper-Marshall personographs) were generated showing beneficial and adverse effects of endovascular thrombectomy for patients with acute cerebral ischemia and large vessel occlusion using (1) automated (algorithmic) and (2) expert-guided joint outcome table specification.

RESULTS

For the full 7-category modified Rankin Scale, thrombectomy added to IV tPA (intravenous tissue-type plasminogen activator) alone had number needed to treat to benefit 2.9 (95% confidence interval, 2.6-3.3) and number needed to harm 68.9 (95% confidence interval, 40-250); thrombectomy for patients ineligible for IV tPA had number needed to treat to benefit 2.3 (95% confidence interval, 2.1-2.5) and number needed to harm 100 (95% confidence interval, 62.5-250). Visual displays of treatment effects on 100 patients showed: with thrombectomy added to IV tPA alone, 34 patients have better disability outcome, including 14 more normal or near normal (modified Rankin Scale, 0-1); with thrombectomy for patients ineligible for IV tPA, 44 patients have a better disability outcome, including 16 more normal or nearly normal. Displays also showed that harm (increased modified Rankin Scale final disability) occurred in 1 of 100 patients in both populations, mediated by increased new territory infarcts. The person-icon figures integrated these outcomes, and early side-effects, in a single display.

CONCLUSIONS

Visual decision aids are now available to rapidly educate healthcare providers, patients, and families about benefits and risks of endovascular thrombectomy, both when added to IV tPA in tPA-eligible patients and as the sole reperfusion treatment in tPA-ineligible patients.

Implementation of stroke teams and simulation training shortened process times in a regional stroke network-A network-wide prospective trial

Background

To meet the requirements imposed by the time-dependency of acute stroke therapies, it is necessary 1) to initiate structural and cultural changes in the breadth of stroke-ready hospitals and 2) to find new ways to train the personnel treating patients with acute stroke. We aimed to implement and validate a composite intervention of a stroke team algorithm and simulation-based stroke team training as an effective quality initiative in our regional interdisciplinary neurovascular network consisting of 7 stroke units.

Methods

We recorded door-to-needle times of all consecutive stroke patients receiving thrombolysis at seven stroke units for 3 months before and after a 2 month intervention which included setting up a team-based stroke workflow at each stroke unit, a train-the-trainer seminar for stroke team simulation training and a stroke team simulation training session at each hospital as well as a recommendation to take up regular stroke team trainings.

Results

The intervention reduced the network-wide median door-to-needle time by 12 minutes from 43,0 (IQR 29,8–60,0, n = 122) to 31,0 (IQR 24,0–42,0, n = 112) minutes (p < 0.001) and substantially increased the share of patients receiving thrombolysis within 30 minutes of hospital arrival from 41.5% to 59.6% (p < 0.001). Stroke team training participants stated a significant increase in knowledge on the topic of acute stroke care and in the perception of patient safety. The overall course concept was regarded as highly useful by most participants from different professional backgrounds.

Conclusions

The composite intervention of a binding team-based algorithm and stroke team simulation training showed to be well-transferable in our regional stroke network. We provide suggestions and materials for similar campaigns in other stroke networks.

Prediction of Symptomatic Intracranial Hemorrhage after Intravenous Thrombolysis in Acute Ischemic Stroke: The Symptomatic Intracranial Hemorrhage Score

BACKGROUND

Symptomatic intracranial hemorrhage (sICH) is common after intravenous thrombolysis in acute ischemic strokes (AISs). Available predictive scoring systems were derived mostly in the Western countries.

METHODS

Retrospective data in 1 provincial and 4 regional hospitals in the northern part of Thailand were reviewed. Patients with AIS, to whom recombinant tissue plasminogen activator (rt-PA) had been prescribed, were classified into 3 groups: no intracranial hemorrhage (no ICH), asymptomatic intracranial hemorrhage (asICH) and sICH. Coefficients under the multilevel ordinal logistic model were transformed into item scores and sum scores. Measures of discrimination, calibration, and internal validation were analyzed.

RESULTS

Among 1172 patients, there were 78.8% with no ICH (n = 923), 13.1% with asICH (n = 154), and 8.1% with sICH (n = 95). The final model was named "SICH score" and included 6 variables: valvular heart diseases, use of aspirin, systolic blood pressure prior to thrombolysis that is 140 mmHg or higher, National Institutes of Health Stroke Scale scores higher than 10 and 20, a platelet count lower than 250,000 cell/mm3, and use of intravenous antihypertensive drugs during thrombolysis, with an Area under Receiver Operating Characteristic of .75 (95% confidence interval, .71-.80).

CONCLUSION

The SICH score could be an assisting tool to predict an individual risk of sICH after intravenous thrombolysis for AIS in Thai patients.

Interaction of ARC and Daxx: A Novel Endogenous Target to Preserve Motor Function and Cell Loss after Focal Brain Ischemia in Mice

The aim of this study was to explore the signaling and neuroprotective effect of transactivator of transcription (TAT) protein transduction of the apoptosis repressor with CARD (ARC) in in vitro and in vivo models of cerebral ischemia in mice. In mice, transient focal cerebral ischemia reduced endogenous ARC protein in neurons in the ischemic striatum at early reperfusion time points, and in primary neuronal cultures, RNA interference resulted in greater neuronal susceptibility to oxygen glucose deprivation (OGD). TAT.ARC protein delivery led to a dose-dependent better survival after OGD. Infarct sizes 72 h after 60 min middle cerebral artery occlusion (MCAo) were on average 30 ± 8% (mean ± SD; p = 0.005; T2-weighted MRI) smaller in TAT.ARC-treated mice (1 μg intraventricularly during MCAo) compared with controls. TAT.ARC-treated mice showed better performance in the pole test compared with TAT.β-Gal-treated controls. Importantly, post-stroke treatment (3 h after MCAo) was still effective in affording reduced lesion volume by 20 ± 7% (mean ± SD; p < 0.05) and better functional outcome compared with controls. Delayed treatment in mice subjected to 30 min MCAo led to sustained neuroprotection and functional behavior benefits for at least 28 d. Functionally, TAT.ARC treatment inhibited DAXX-ASK1-JNK signaling in the ischemic brain. ARC interacts with DAXX in a CARD-dependent manner to block DAXX trafficking and ASK1-JNK activation. Our work identifies for the first time ARC-DAXX binding to block ASK1-JNK activation as an ARC-specific endogenous mechanism that interferes with neuronal cell death and ischemic brain injury. Delayed delivery of TAT.ARC may present a promising target for stroke therapy.

SIGNIFICANCE STATEMENT

Up to now, the only successful pharmacological target of human ischemic stroke is thrombolysis. Neuroprotective pharmacological strategies are needed to accompany therapies aiming to achieve reperfusion. We describe that apoptosis repressor with CARD (ARC) interacts and inhibits DAXX and proximal signals of cell death. In a murine stroke model mimicking human malignant infarction in the territory of the middle cerebral artery, TAT.ARC salvages brain tissue when given during occlusion or 3 h delayed with sustained functional benefits (28 d). This is a promising novel therapeutic approach because it appears to be effective in a model producing severe injury by interfering with an array of proximal signals and effectors of the ischemic cascade, upstream of JNK, caspases, and BIM and BAX activation.

Targeting resolution of neuroinflammation after ischemic stroke with a lipoxin A4 analog: Protective mechanisms and long-term effects on neurological recovery

BACKGROUND

Resolution of inflammation is an emerging new strategy to reduce damage following ischemic stroke. Lipoxin A₄ (LXA ₄) is an anti-inflammatory, pro-resolution lipid mediator that reduces neuroinflammation in stroke. Since LXA ₄ is rapidly inactivated, potent analogs have been synthesized, including BML-111. We hypothesized that post-ischemic, intravenous treatment with BML-111 for 1 week would provide neuroprotection and reduce neurobehavioral deficits at 4 weeks after ischemic stroke in rats. Additionally, we investigated the potential protective mechanisms of BML-111 on the post-stroke molecular and cellular profile.

METHODS

A total of 133 male Sprague-Dawley rats were subjected to 90 min of transient middle cerebral artery occlusion (MCAO) and BML-111 administration was started at the time of reperfusion. Two methods of week-long BML-111 intravenous administration were tested: continuous infusion via ALZET ^® osmotic pumps (1.25 and 3.75 μg μl^-1 hr^-1), or freshly prepared daily single injections (0.3, 1, and 3 mg/kg). We report for the first time on the stability of BML-111 and characterized an optimal dose and a dosing schedule for the administration of BML-111.

RESULTS

One week of BML-111 intravenous injections did not reduce infarct size or improve behavioral deficits 4 weeks after ischemic stroke. However, post-ischemic treatment with BML-111 did elicit early protective effects as demonstrated by a significant reduction in infarct volume and improved sensorimotor function at 1 week after stroke. This protection was associated with reduced pro-inflammatory cytokine and chemokine levels, decreased M1 CD40+ macrophages, and increased alternatively activated, anti-inflammatory M2 microglia/macrophage cell populations in the post-ischemic brain.

CONCLUSION

These data suggest that targeting the endogenous LXA ₄ pathway could be a promising therapeutic strategy for the treatment of ischemic stroke. More work is necessary to determine whether a different dosing regimen or more stable LXA ₄ analogs could confer long-term protection.

Number needed to treat for stroke thrombectomy based on a systematic review and meta-analysis

The positive results of recent clinical trials examining endovascular treatment of acute stroke were the culmination of nearly two decades of studies of endovascular stroke treatment. We systematically reviewed this body of work, evaluated the strength of evidence, and performed a meta-analysis to define the clinical impact of these investigations. Terms were entered into search engines in a systematic fashion. Articles were reviewed independently by study authors, graded for level of evidence, and combined in a meta-analysis. The overall body of evidence was evaluated using GRADE criteria. Our search yielded 948 articles. Twenty-five met predefined inclusion criteria. We identified 12 grade I, 1 grade II, 5 grade III, and 7 grade IV studies (κ=0.86). Meta-analysis for independence at 90days showed a benefit of endovascular treatment (grade I studies OR 1.58 [1.20-2.07]). When limiting the analysis to studies using stent retriever, the OR increased to 2.44 (1.77-3.36). The number needed to treat (NNT) was 8. Endovascular treatment was not associated with increased symptomatic intracranial hemorrhage, and forgoing endovascular treatment was associated with death at 90 days. The quality of evidence according to GRADE criteria was "moderate." In summary, we found impressive evidence for a benefit of endovascular treatment of acute stroke, particularly when using stent retriever devices. Our meta-analysis is unique in that it includes all studies related to this topic and defines the clinical impact of the data, providing NNT. We show that thrombectomy is among the most effective stroke treatments currently available.

[Why is reperfusion therapy delayed in stroke code patients? A qualitative analysis]

BACKGROUND

Efficacy and safety of reperfusion therapy in acute ischaemic stroke is time-dependent and has a limited therapeutic window, which is, in fact, the main exclusion criterion. Initiatives to evaluate the quality of care are essential to design future interventions and ensure the shortest management times and application of such treatments.

OBJECTIVE

The aim of the study is to identify and classify potential causes of delay in the administration of reperfusion therapy in a tertiary hospital, a reference for the comprehensive treatment of acute ischaemic stroke.

MATERIAL AND METHODS

The project was developed in Hospital Universitario Virgen de la Arrixaca, Murcia, Spain. A total of 337 patients with acute ischaemic stroke treated with reperfusion therapies were evaluated. For qualitative analysis, 2 working groups were formed: an advocacy group that designed and directed the entire project, and a multidisciplinary one, which served as a source of information and a mechanism for active involvement of all professionals in the stroke-care chain. Information was collected in 3 meetings and then, both the flowcharts and the cause-effect diagram were prepared.

RESULTS

Based on the above tools, potential causes of delay were identified and classified according to an operational criterion into unmodified structures, and modifiable ones with known evidence and hypothetical repercussions. Modifiable ones are noted for their importance in the design of future improvement interventions in stroke care. Some of them are: Variability in following established protocols, lack of procedures in some parts of the stroke-care chain, etc.

CONCLUSION

Knowledge of the current situation has just been the starting point, but it has been an essential requisite for the design and implementation of a quality improvement program to shorten in-hospital stroke code times.

Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials

BACKGROUND

In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included.

METHODS

We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation.

FINDINGS

We analysed individual data for 1287 patients (634 assigned to endovascular thrombectomy, 653 assigned to control). Endovascular thrombectomy led to significantly reduced disability at 90 days compared with control (adjusted cOR 2.49, 95% CI 1.76-3.53; p<0.0001). The number needed to treat with endovascular thrombectomy to reduce disability by at least one level on mRS for one patient was 2.6. Subgroup analysis of the primary endpoint showed no heterogeneity of treatment effect across prespecified subgroups for reduced disability (pinteraction=0.43). Effect sizes favouring endovascular thrombectomy over control were present in several strata of special interest, including in patients aged 80 years or older (cOR 3.68, 95% CI 1.95-6.92), those randomised more than 300 min after symptom onset (1.76, 1.05-2.97), and those not eligible for intravenous alteplase (2.43, 1.30-4.55). Mortality at 90 days and risk of parenchymal haematoma and symptomatic intracranial haemorrhage did not differ between populations.

INTERPRETATION

Endovascular thrombectomy is of benefit to most patients with acute ischaemic stroke caused by occlusion of the proximal anterior circulation, irrespective of patient characteristics or geographical location. These findings will have global implications on structuring systems of care to provide timely treatment to patients with acute ischaemic stroke due to large vessel occlusion.

FUNDING

Medtronic.

Safety and Efficacy of Solitaire Stent Thrombectomy: Individual Patient Data Meta-Analysis of Randomized Trials

BACKGROUND AND PURPOSE

Recent positive randomized trials of endovascular therapy for ischemic stroke used predominantly stent retrievers. We pooled data to investigate the efficacy and safety of stent thrombectomy using the Solitaire device in anterior circulation ischemic stroke.

METHODS

Patient-level data were pooled from trials in which the Solitaire was the only or the predominant device used in a prespecified meta-analysis (SEER Collaboration): Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME), Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE), Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial (EXTEND-IA), and Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset (REVASCAT). The primary outcome was ordinal analysis of modified Rankin Score at 90 days. The primary analysis included all patients in the 4 trials with 2 sensitivity analyses: (1) excluding patients in whom Solitaire was not the first device used and (2) including the 3 Solitaire-only trials (excluding ESCAPE). Secondary outcomes included functional independence (modified Rankin Score 0-2), symptomatic intracerebral hemorrhage, and mortality.

RESULTS

The primary analysis included 787 patients: 401 randomized to endovascular thrombectomy and 386 to standard care, and 82.6% received intravenous thrombolysis. The common odds ratio for modified Rankin Score improvement was 2.7 (2.0-3.5) with no heterogeneity in effect by age, sex, baseline stroke severity, extent of computed tomography changes, site of occlusion, or pretreatment with alteplase. The number needed to treat to reduce disability was 2.5 and for an extra patient to achieve independent outcome was 4.25 (3.29-5.99). Successful revascularization occurred in 77% treated with Solitaire device. The rate of symptomatic intracerebral hemorrhage and overall mortality did not differ between treatment groups.

CONCLUSIONS

Solitaire thrombectomy for large vessel ischemic stroke was safe and highly effective with substantially reduced disability. Benefits were consistent in all prespecified subgroups.

Mechanical Thrombectomy-Ready Comprehensive Stroke Center Requirements and Endovascular Stroke Systems of Care: Recommendations from the Endovascular Stroke Standards Committee of the Society of Vascular and Interventional Neurology (SVIN)

Five landmark multicenter, prospective, randomized, open-label, blinded end point clinical trials have recently demonstrated significant clinical benefit of endovascular therapy with mechanical thrombectomy in acute ischemic stroke (AIS) patients presenting with proximal intracranial large vessel occlusions. The Society of Vascular and Interventional Neurology (SVIN) appointed an expert writing committee to summarize this new evidence and make recommendations on how these data should guide emergency endovascular therapy for AIS patients.

Mechanical thrombectomy for emergent large vessel occlusion: a critical appraisal of recent randomized controlled clinical trials

BACKGROUND AND PURPOSE

After numerous attempts to prove efficacy for endovascular treatment of ischemic stroke, a series of recent randomized controlled clinical trials (RCTs) established fast mechanical thrombectomy (MT) as a safe and effective novel treatment for emergent large vessel occlusion (ELVO) in the anterior cerebral circulation.

METHODS

We reviewed five recent RCTs that evaluated the safety and efficacy of MT in ELVO patients and captured available information on recanalization/reperfusion, symptomatic intracranial hemorrhage (sICH), clinical outcome, and mortality. MT was performed with stent retrievers, aspiration techniques, or a combination of these endovascular approaches. We applied meta-analytical methodology to evaluate the pooled effect of MT on recanalization/reperfusion, sICH, functional independence (modified Rankin scale score of 0-2) and 3-month mortality rates in comparison to best medical therapy (BMT).

RESULTS

MT was associated with increased likelihood of complete recanalization/reperfusion (RR: 2.22; 95%CI: 1.89-2.62; P < 0.00001) and 3-month functional independence (RR: 1.72; 95%CI: 1.48-1.99; P < 0.00001) without any heterogeneity across trials (I (2) = 0%). The absolute benefit increase in MT for complete recanalization/reperfusion and functional independence was 44 (NNT = 2) and 16 (NNT = 6), respectively. MT was not associated with increased risk of 3-month mortality (15% with MT vs. 19% with BMT) and sICH (4.6% with MT vs. 4.3% with BMT), while small heterogeneity was detected across the included trials (I (2) < 25%).

CONCLUSIONS

MT is a safe and highly effective treatment for patients with ELVO in the anterior circulation. For every six ELVO patients treated with MT three more will achieve complete recanalization at 24 h following symptom onset and one more will be functionally independent at 3 months in comparison to BMT.

An in vitro porcine model evaluating a novel stent retriever for thrombectomy of the common carotid artery

OBJECTIVES

This study aimed to test the safety and efficiency of a novel stent retriever, RECO, in a swine model.

BACKGROUND

The stent retrievers show great benefit for patients with acute ischemic stroke.

METHODS

The framework of the stent was optimized. The proximal stent was closed; mechanical connection replaced the electrolysis connection and the push wire located on the longitudinal axis. After tests in vitro, the safety and thrombectomy efficiency of RECO device were evaluated by angiography and histological analysis in a swine model with placement of experimental soft or hard thrombi.

RESULTS

No device-related thrombi were observed on the perioperative term or 1 month later. The endothelial cells were intact and the smooth muscle cells did not migrate or proliferate. Device-related vasospasm was detected in 9% vessels undergoing the procedure and was alleviated after delivery of a dose of nitroglycerin. The RECO device demonstrated a high recanalization rate in the target vessels with a mean of 1.3 runs. No residual thrombi were observed under the DSA or microscope.

CONCLUSIONS

Our data indicated that RECO device was a novel, safe and effective stent based clot retriever. A phase IIa clinical trial, RESTORE, is undergoing (NCT01983644).

Intravenous Thrombolysis for Acute Ischemic Stroke Within 3 Hours Versus Between 3 and 4.5 Hours of Symptom Onset

Data from randomized clinical trials have supported the safety and efficacy of intravenous tissue-type plasminogen activator (IV tPA) for acute ischemic stroke when administered within 3 hours of symptom onset, and regulatory approvals for this indication have been in place for almost 20 years. However, recent clinical trials have provided evidence that IV tPA may be safe and effective in selected patients up to 4.5 hours after symptom onset, thereby increasing the proportion of patients that may be eligible for treatment. Although professional organizations in the United States and many regulatory agencies internationally have supported this expanded time window for IV tPA, the US Food and Drug Administration has declined to approve this expanded indication and so this use of IV tPA has remained off-label in the United States. Here we review the current evidence for IV tPA in the standard and the expanded time windows and the data on current clinical practice in the United States as it relates to IV tPA treatment for acute stroke within 3 to 4.5 hours of symptom onset.

Time to endovascular reperfusion and degree of disability in acute stroke

OBJECTIVE

Faster time from onset to recanalization (OTR) in acute ischemic stroke using endovascular therapy (ET) has been associated with better outcome. However, previous studies were based on less-effective first-generation devices, and analyzed only dichotomized disability outcomes, which may underestimate the full effect of treatment.

METHODS

In the combined databases of the SWIFT and STAR trials, we identified patients treated with the Solitaire stent retriever with achievement of substantial reperfusion (Thrombolysis in Cerebral Infarction [TICI] 2b-3). Ordinal numbers needed to treat values were derived by populating joint outcome tables.

RESULTS

Among 202 patients treated with ET with TICI 2b to 3 reperfusion, mean age was 68 (±13), 62% were female, and median National Institutes of Health Stroke Scale (NIHSS) score was 17 (interquartile range [IQR]: 14-20). Day 90 modified Rankin Scale (mRS) outcomes for OTR time intervals ranging from 180 to 480 minutes showed substantial time-related reductions in disability across the entire outcome range. Shorter OTR was associated with improved mean 90-day mRS (1.4 vs. 2.4 vs. 3.3, for OTR groups of 124-240 vs. 241-360 vs. 361-660 minutes; p < 0.001). The number of patients identified as benefitting from therapy with shorter OTR were 3-fold (range, 1.5-4.7) higher on ordinal, compared with dichotomized analysis. For every 15-minute acceleration of OTR, 34 per 1,000 treated patients had improved disability outcome.

INTERPRETATION

Analysis of disability over the entire outcome range demonstrates a marked effect of shorter time to reperfusion upon improved clinical outcome, substantially higher than binary metrics. For every 5-minute delay in endovascular reperfusion, 1 of 100 patients has a worse disability outcome.

Associations of chronic heart failure with outcome in acute ischaemic stroke patients who received systemic thrombolysis: analysis from VISTA

BACKGROUND AND PURPOSE

There are concerns that systemic thrombolysis might not achieve clinically important outcome amongst chronic heart failure (CHF) patients with acute ischaemic stroke. Our aim was to investigate the relevance of CHF on the outcome of acute stroke patients who received thrombolysis.

METHODS

A non-randomized cohort analysis was conducted using data obtained from the Virtual International Stroke Trials Archive. The association of outcome amongst CHF patients with thrombolysis treatment was described using the modified Rankin scale (mRS) distribution at day 90, stratified by the presence of atrial fibrillation. Dichotomized outcomes were considered as a secondary end-point.

RESULTS

5677 patients were identified, of whom 2366 (41.7%) received thombolysis. Five hundred and three (8.9%) patients had CHF, of whom 209 (41.6%) received thrombolysis. The presence of CHF was associated with a negative impact on overall stroke outcome [odds ratio (OR) 0.73 (95% confidence interval (CI) 0.62-0.87), P < 0.001]. However, thrombolysis treatment was associated with favourable functional outcome using ordinal mRS, irrespective of CHF status, after adjustment for age and baseline National Institutes of Health Stroke Scale [OR 1.44 (95% CI 1.04-2.01, P = 0.029) for CHF patients versus OR 1.50 (95% CI 1.36-1.66, P < 0.001) for non-CHF patients]. CHF patients had higher mortality at day 90 than non-CHF patients. There was no significant difference for recurrent stroke or symptomatic intracerebral haemorrhage within 7 days of the initial stroke between CHF and thrombolysis groups.

CONCLUSIONS

Chronic heart failure was associated with a worse outcome with or without thrombolysis. However, acute stroke patients who received thrombolysis had more favourable outcome regardless of CHF status, compared with their untreated peers. Our findings should reassure clinicians considering systemic thrombolysis treatment in hyperacute ischaemic stroke patients with CHF.

Thrombolysis for acute ischaemic stroke

BACKGROUND

Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009.

OBJECTIVES

To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available.

MAIN RESULTS

We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke.

AUTHORS' CONCLUSIONS

Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.

Thrombolysis ImPlementation in Stroke (TIPS): evaluating the effectiveness of a strategy to increase the adoption of best evidence practice--protocol for a cluster randomised controlled trial in acute stroke care

Background

Stroke is a leading cause of death and disability internationally. One of the three effective interventions in the acute phase of stroke care is thrombolytic therapy with tissue plasminogen activator (tPA), if given within 4.5 hours of onset to appropriate cases of ischaemic stroke.

Objectives

To test the effectiveness of a multi-component multidisciplinary collaborative approach compared to usual care as a strategy for increasing thrombolysis rates for all stroke patients at intervention hospitals, while maintaining accepted benchmarks for low rates of intracranial haemorrhage and high rates of functional outcomes for both groups at three months.

Methods and design

A cluster randomised controlled trial of 20 hospitals across 3 Australian states with 2 groups: multi- component multidisciplinary collaborative intervention as the experimental group and usual care as the control group. The intervention is based on behavioural theory and analysis of the steps, roles and barriers relating to rapid assessment for thrombolysis eligibility; it involves a comprehensive range of strategies addressing individual-level and system-level change at each site. The primary outcome is the difference in tPA rates between the two groups post-intervention. The secondary outcome is the proportion of tPA treated patients in both groups with good functional outcomes (modified Rankin Score (mRS <2) and the proportion with intracranial haemorrhage (mRS ≥2), compared to international benchmarks.

Discussion

TIPS will trial a comprehensive, multi-component and multidisciplinary collaborative approach to improving thrombolysis rates at multiple sites. The trial has the potential to identify methods for optimal care which can be implemented for stroke patients during the acute phase. Study findings will include barriers and solutions to effective thrombolysis implementation and trial outcomes will be published whether significant or not.

Trial registration

Australian New Zealand Clinical Trials Registry: ACTRN12613000939796

Current perspectives on the use of intravenous recombinant tissue plasminogen activator (tPA) for treatment of acute ischemic stroke

In 1995, the NINDS (National Institute of Neurological Disorders and Stroke) tPA (tissue plasminogen activator) Stroke Study Group published the results of a large multicenter clinical trial demonstrating efficacy of intravenous tPA by revealing a 30% relative risk reduction (absolute risk reduction 11%-15%) compared with placebo at 90 days in the likelihood of having minimal or no disability. Since approval in 1996, tPA remains the only drug treatment for acute ischemic stroke approved by the US Food and Drug Administration. Over the years, an abundance of research and clinical data has supported the safe and efficacious use of intravenous tPA in all eligible patients. Despite such supporting data, it remains substantially underutilized. Challenges to the utilization of tPA include narrow eligibility and treatment windows, risk of symptomatic intracerebral hemorrhage, perceived lack of efficacy in certain high-risk subgroups, and a limited pool of neurological and stroke expertise in the community. With recent US census data suggesting annual stroke incidence will more than double by 2050, better education and consensus among both the medical and lay public are necessary to optimize the use of tPA for all eligible stroke patients. Ongoing and future research should continue to improve upon the efficacy of tPA through more rapid stroke diagnosis and treatment, refinement of advanced neuroimaging and stroke biomarkers, and successful demonstration of alternative means of reperfusion.

Management of ischaemic stroke in the acute setting: review of the current status

Abstract

Acute ischaemic stroke can be treated by clot busting and clot removal. Thrombolysis using intravenous recombinant-tissue plasminogen activator (IV r-TPA) is the current gold standard for the treatment of acute ischaemic stroke (AIS). The main failure of this type of treatment is the short time interval from stroke onset within which it has to be used for any benefit. The evidence is that IV r-TPA has to be used within 4.5 hours.

Other modalities of treatment are not as effective and need more scrutiny and examination. The available modalities are intra-arterial thrombolysis and clot-retrieval devices. Not unexpectedly, recanalisation treatments have flourished at a rapid rate. Although vessel recanalisation is vital to increasing the possibility of significant tissue reperfusion, clinical trials need to emphasise functional outcomes rather than reperfusion/recanalisation rates to adequately assess success of these devices/techniques.

Our view is that until these treatments become proven in large-scale studies, a greater endeavour should be made in resource-limited settings to expand facilities to enable intravenous r-tPA treatment within the 4.5-hour period following onset of stroke. The resources required are small with the main costs being a CT scan of the brain and the cost of r-tPA. This can easily be done in any emergency facility in any part of the world. What is needed is public awareness, and campaigns of ‘stroke attack’ should be revisited, especially in the resource-limited context. This approach at present will halt to some extent the stroke pandemic that we are facing.

siRNA Treatment: "A Sword-in-the-Stone" for Acute Brain Injuries

Ever since the discovery of small interfering ribonucleic acid (siRNA) a little over a decade ago, it has been highly sought after for its potential as a therapeutic agent for many diseases. In this review, we discuss the promising possibility of siRNA to be used as a drug to treat acute brain injuries such as stroke and traumatic brain injury. First, we will give a brief and basic overview of the principle of RNA interference as an effective mechanism to decrease specific protein expression. Then, we will review recent in vivo studies describing siRNA research experiments/treatment options for acute brain diseases. Lastly, we will discuss the future of siRNA as a clinical therapeutic strategy against brain diseases and injuries, while addressing the current obstacles to effective brain delivery.