A meta-analysis of prospective randomized controlled trials evaluating endovascular therapies for acute ischemic stroke

Extended treatment in cerebral ischemia score 2c or 3 as goal of successful endovascular treatment is associated with clinical benefit

BACKGROUND AND PURPOSE

Successful reperfusion, defined as a modified treatment in cerebral ischemia (mTICI) score 2b or 3, is an important goal for endovascular treatment (EVT) of stroke. Recently, an extension of the mTICI score with an additional grade 2c indicating near-complete reperfusion (expanded TICI, eTICI) and a revised definition of success as eTICI 2c or 3 were proposed. We evaluate whether eTICI 2c translates into improved clinical outcome compared to eTICI 2b.

MATERIAL AND METHODS

Consecutive patients with large vessel occlusion in the anterior circulation who underwent EVT between December 2013 and December 2020 were included. Clinical outcome measures were favorable functional outcome at 90 days (modified Rankin Scale [mRS] scores 0 to 2 or return to pre-stroke mRS) and early neurological improvement (National Institutes of Health Stroke Scale [NIHSS] improvement ≥4 points or a score of 0-1 at 24 h).

RESULTS

Of 1282 included patients (median age 76, median NIHSS 16), reperfusion was classified as eTICI 2b in 410 (32%), eTICI 2c in 242 (19%) and eTICI 3 in 464 (36%). eTICI 2c differed significally from 2b with respect to early neurological improvement (aOR = 1.49, 95% CI = 1.01-2.19). No statistically significant difference in favorable functional outcome at 90 days was found (eTICI 2c vs 2b, aOR = 1.31, 95% CI = 0.88-2.00).

CONCLUSION

Our study indicates early clinical benefit at 24 h of achieving eTICI 2c compared to eTICI 2b, but no significant difference was seen in favorable functional outcome at 90 days. Our results support eTICI 2c and 3 as the goal of a successful thrombectomy but do not exclude eTICI 2b as an acceptable result.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Does the administration of sonothrombolysis along with tissue plasminogen activator improve outcomes in acute ischemic stroke? A systematic review and meta-analysis

This meta-analysis was conducted to assess the safety and efficacy of sonothrombolysis along with intravenous recombinant tissue plasminogen activator, alteplase (IV rtPA), in the management of acute ischemic stroke. Electronic databases were searched under different meSH terms without the restriction of time and language. 1415 studies were analyzed and seven studies that matched the inclusion criteria were selected. Multiple safety and efficacy outcomes were extracted. Our pooled analysis demonstrated that there is no significant difference between sonothrombolysis group and control group in preventing mortality (RR 1.10 [0.81, 1.50]; p = 0.55; I² = 0%) and intracranial hemorrhage (RR 1.11 [0.76, 1.63]; p = 0.59; i² = 0%), however, among the efficacy outcomes; complete recanalization after 60-120 min was achieved more effectively in the sonothrombolysis group (RR 2.11 [1.48, 3.03]; p ≤ 0.0001; I² = 0%). The rest of the efficacy outcomes like neurological improvement at 24 h (RR 1.20 [0.92, 1.57]; p = 0.18; I² = 40%) and excellent functional outcome after 3 months (RR 1.19 [0.93, 1.52]; p = 0.17; I² = 35%) showed no significant differences between the two groups. In subgroup analysis, we found that sonothrombolysis led to a better neurological improvement in patients who were less than 65 years of age (RR 1.20 [0.92, 1.57]; p = 0.05; I² = 40%). Moreover, there were no significant differences in the following of the subgroups assessed: (a) microsphere or microbubble use, (b) Ultrasound frequency (2 MHz or < 2 MHz), (c) transcranial Doppler (TCD) duration (1 h or 2 h), (d) age (≤ 65 or > 65).

Systematic review of organizational models for intra-arterial treatment of acute ischemic stroke

Background

Intra-arterial treatment of acute ischemic stroke requires changes to acute stroke services since most hospitals do not have on-site intra-arterial treatment facilities.

Aim

To identify models for delivery of intra-arterial treatment and to compare process performance and clinical and radiological outcomes of the different models.

Methods

We systematically searched the literature and contacted experts in the field. We performed a qualitative synthesis to identify models, and a quantitative review and meta-analysis of clinical and radiological outcomes under different organizational models.

Summary of review

The searches retrieved 148 publications, of which 27 were used for the identification and description of models, and 9 for the comparison of the different models. We identified four main models: the mother-ship, drip-and ship, mobile interventionist, and mobile stroke unit models. There were no randomized-controlled trials of the different models, but non-randomized comparisons were possible using data from 8 observational studies and 1 randomized-controlled trial of intra-arterial therapy, of a total of 4127 patients. Comparison between the mother-ship and drip-and-ship models showed no difference in survival (OR 0.81; 95% CI 0.63–1.03), favorable functional outcome (OR 0.96; 95% CI 0.73–1.25), or arterial patency (OR 0.89; 95% CI 0.73–1.08).

Conclusions

Different organizational models exist for intra-arterial treatment of acute ischemic stroke, but there is insufficient evidence to recommend a particular, universal model. Until one model can be shown to be superior, the choice of model should depend on local factors and patient characteristics.

The Role of von Willebrand Factor, ADAMTS13, and Cerebral Artery Thrombus Composition in Patient Outcome Following Mechanical Thrombectomy for Acute Ischemic Stroke

Background

The aim of the study was to investigate the role of von Willebrand factor (vWF), the vWF-cleaving protease, ADAMTS13, the composition of thrombus, and patient outcome following mechanical cerebral artery thrombectomy in patients with acute ischemic stroke.

Material/Methods

A prospective cohort study included 131 patients with ischemic stroke (<6 hours) with or without intravenous thrombolysis. Interventional procedure parameters, hemocoagulation markers, vWF, ADAMTS13, and histological examination of the extracted thrombi were performed. The National Institutes of Health Stroke Scale (NIHSS) score was used on hospital admission, after 24 hours, at day 7; the three-month modified Rankin Scale score was used.

Results

Mechanical thrombectomy resulted in a Treatment in Cerebral Ischemia (TICI) score of 2–3, with recanalization in 89% of patients. Intravenous thrombolysis was used in 101 (78%). Patients with and without intravenous thrombolysis therapy had a good clinical outcome (score 0–2) in 47% of cases (P=0.459) using the three-month modified Rankin Scale. Patients with a National Institutes of Health Stroke Scale (NIHSS) score ≥15 had significantly increased vWF levels (P=0.003), and a significantly increased vWF: ADAMTS13 ratio (P=0.038) on hospital admission. Significant correlation coefficients were found for plasma vWF and thrombo-embolus vWF (r=0.32), platelet (r=0.24), and fibrin (r=0.26) levels. In the removed thrombus, vWF levels were significantly correlated with platelet count (r=0.53), CD31-positive cells (r=0.38), and fibrin (r=0.48).

Conclusions

In patients with acute ischemic stroke, mechanical cerebral artery thrombectomy resulted in a good clinical outcome in 47% of cases, with and without intravenous thrombolysis therapy.

An Overview of Meta-Analyses of Endovascular Bridging Therapies for Acute Ischemic Stroke

Background

Acute Ischemic Stroke (AIS) is a common cause of death worldwide and the leading cause of long-term severe disability. Endovascular bridging therapies (EBT), including endovascular thrombectomy (ET) and intra-arterial thrombolytic (IAT), have been recommended to realize a favorable functional outcome for AIS patients.

Methods

An overview of meta-analyses of primary randomized controlled trial (RCT) studies was performed evaluating EBT for AIS patients compared with usual care.

Results

Ten meta-analyses were included in this overview. ET was associated with a higher incidence of achieving functional outcome improvement, defined as a modified Rankin scale of 0 to 1 (mRS, p = 0.003), 0 to 2 (p < 0.00001), and 0 to 3 (p = 0.005). The risk of symptomatic intracranial hemorrhage (sICH) rate and all-cause mortality were similar between the two groups. Moreover, IAT treatment was also related to significantly improved outcomes in terms of the mRS score (p < 0.05), but no significant difference in rates of sICH and mortality within 90 days.

Conclusions

In conclusion, our analysis supports that EBT, regardless of format (e.g., ET or IAT), is superior to the best medical therapy alone (e.g., IVT) in terms of mRS score in patients with AIS. In addition, the safety of EBT is similar to IVT.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Endovascular Treatment versus Best Medical Treatment in Patients with Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND PURPOSE

Endovascular treatment has emerged as a minimally invasive technique for patients with acute ischemic stroke to achieve recanalization. Our aim was to determine the effects of endovascular treatment on clinical and safety outcomes compared with best medical treatment.

MATERIALS AND METHODS

Fifteen randomized trials that compared endovascular treatment with best medical treatment in patients with acute ischemic stroke met the inclusion criteria. We calculated pooled odds ratios and 95% CIs by using random-effects models. The primary end point was a favorable outcome defined by a modified Rankin Scale score of 0 (no symptoms), 1 (no significant disability), or 2 (slight disability) at 90 days postrandomization.

RESULTS

Of the 2980 subjects randomized, the proportion of subjects who achieved a favorable outcome was significantly greater among those randomized to endovascular treatment compared with best medical treatment (2949 subjects analyzed; odds ratio, 1.82; 95% CI, 1.38-2.40; P < .001). Excellent outcome (modified Rankin Scale score of 0 or 1) was also significantly greater among those randomized to endovascular treatment (2791 subjects analyzed; odds ratio, 1.77; 95% CI, 1.29-2.43, P < .001). Risk of symptomatic intracranial hemorrhage was similar between endovascular treatment and best medical treatment (2906 subjects analyzed; odds ratio, 1.19; 95% CI, 0.84-1.68; P = .34).

CONCLUSIONS

Compared with best medical treatment, the odds of achieving a favorable outcome or excellent outcome at 3 months postrandomization are approximately 80% higher with endovascular treatment among patients with acute ischemic stroke.

Endovascular treatment versus medical care alone for ischaemic stroke: systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy and safety of endovascular treatment, particularly adjunctive intra-arterial mechanical thrombectomy, in patients with ischaemic stroke.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, SciELO, LILACS, and clinical trial registries from inception to December 2015. Reference lists were crosschecked.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials in adults aged 18 or more with ischaemic stroke comparing endovascular treatment, including thrombectomy, with medical care alone, including intravenous recombinant tissue plasminogen activator (rt-PA). Trial endpoints were functional outcome (modified Rankin scale scores of ≤2) and mortality at 90 days after onset of symptoms. No language or time restrictions applied.

RESULTS

10 randomised controlled trials (n=2925) were included. In pooled analysis endovascular treatment, including thrombectomy, was associated with a higher proportion of patients experiencing good (modified Rankin scale scores ≤2) and excellent (scores ≤1) outcomes 90 days after stroke, without differences in mortality or rates for symptomatic intracranial haemorrhage, compared with patients randomised to medical care alone, including intravenous rt-PA. Heterogeneity was high among studies. The more recent studies (seven randomised controlled trials, published or presented in 2015) proved better suited to evaluate the effect of adjunctive intra-arterial mechanical thrombectomy on its index disease owing to more accurate patient selection, intravenous rt-PA being administered at a higher rate and earlier, and the use of more efficient thrombectomy devices. In most of these studies, more than 86% of the patients were treated with stent retrievers, and rates of recanalisation were higher (>58%) than previously reported. Subgroup analysis of these seven studies yielded a risk ratio of 1.56 (95% confidence interval 1.38 to 1.75) for good functional outcomes and 0.86 (0.69 to 1.06) for mortality, without heterogeneity among the results of the studies. All trials were open label. Risk of bias was moderate across studies. The full results of two trials are yet to be published.

CONCLUSIONS

Moderate to high quality evidence suggests that compared with medical care alone in a selected group of patients endovascular thrombectomy as add-on to intravenous thrombolysis performed within six to eight hours after large vessel ischaemic stroke in the anterior circulation provides beneficial functional outcomes, without increased detrimental effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015019340.

Primary acute stroke thrombectomy within 3 h for large artery occlusion (PAST3-LAO): a pilot study

BACKGROUND AND PURPOSE

In recent trials, acute ischemic stroke (AIS) from large artery occlusion (LAO) was resistant to intravenous thrombolysis and adjunctive stent retriever thrombectomy (SRT) was associated with better perfusion and outcomes. Despite benefit, 39-68% of patients had poor outcomes. Thrombectomy in AIS with LAO within 3 h is performed secondary to intravenous thrombolysis, which may be associated with delay. The purpose of our study is to evaluate the safety, feasibility, recanalization rate, and outcome of primary SRT within 3 h without intravenous thrombolysis in AIS from LAO.

METHODS

Based on an institutionally approved protocol, stroke patients with LAO within 3 h were offered primary SRT as an alternative to intravenous recombinant tissue plasminogen activator. Consecutive patients who underwent primary SRT for LAO within 3 h from 2012 to 2014 were enrolled. Outcomes were measured using the modified Rankin Scale (mRS).

RESULTS

18 patients with LAO of mean age 62.83±15.32 years and median NIH Stroke Scale (NIHSS) score 16 (10-23) chose primary SRT after giving informed consent. Near complete (TICI 2b in 1 patient) or complete (TICI 3 in 17 patients) recanalization was observed in all patients. Time to recanalization from symptom onset and groin puncture was 188.5±82.7 and 64.61±40.14 min, respectively. NIHSS scores immediately after thrombectomy, at 24 h and 30 days were 4 (0-12), 1 (0-12), and 0 (0-4), respectively. Asymptomatic perfusion-related hemorrhage developed in four patients (22%). 90-day outcomes were mRS 0 in 50%, mRS 1 in 44.4%, and mRS 2 in 5.6%.

CONCLUSIONS

Our study demonstrates that primary SRT in AIS from LAO is safe and feasible and is associated with complete recanalization and good outcome. Further study is required.

Logistical and financial obstacles for endovascular therapy of acute stroke implementation

After publication of the recent positive randomized clinical endovascular trials, several questions and obstacles for wide spread implementation remain. We address specific issues namely efficacy, safety, logistics, timing, sedation, numbers, imaging, manpower, centers, geographics, and economical aspects of endovascular therapy. As we move forward, a high degree of collaboration will be crucial to implement a therapy with established overwhelming treatment efficacy for severe acute stroke patients.

Endovascular therapy including thrombectomy for acute ischemic stroke: A systematic review and meta-analysis with trial sequential analysis

One of the primary strategies for the management of acute ischemic stroke is intravenous (IV) thrombolysis with tissue plasminogen activator (t-PA). Over the past decade, endovascular therapies such as the use of stent retrievers to perform mechanical thrombectomy have been found to improve functional outcomes compared to t-PA alone. We aimed to reassess the functional outcomes and complications of IV thrombolysis with and without endovascular treatment for acute ischemic stroke using conventional meta-analysis and trial sequential analysis. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated for the effect of IV thrombolysis with and without endovascular therapy on functional outcome, mortality and symptomatic intracranial hemorrhage (SICH). Trial sequential analysis was done to strengthen the meta-analysis. We analyzed six randomized controlled trials involving 1943 patients. Patients who received IV thrombolysis with endovascular treatment showed significantly higher rates of excellent functional outcomes (modified Rankin Scale [mRS] 0-1) (RR, 1.75 [95% CI, 1.29-2.39]) compared to those who received IV thrombolysis alone. A similar association was seen for good functional outcomes (mRS 0-2) (RR, 1.56 [95% CI, 1.24-1.96]). Trial sequential analysis demonstrated endovascular treatment increased the RR of a good functional outcome by at least 30% compared to IV thrombolysis alone. There was no significant difference in all-cause mortality for mechanical thrombectomy compared to IV thrombolysis alone or the incidence of SICH at 3month follow-up. Endovascular treatment is more likely to result in a better functional outcome for patients compared to IV thrombolysis alone for acute ischemic stroke.

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.

Meta-Analysis of Local Endovascular Therapy for Acute Ischemic Stroke

A meta-analysis was performed to assess randomized controlled trials comparing local endovascular therapy (with and without intravenous thrombolysis) versus standard care (intravenous thrombolysis alone when appropriate) for acute ischemic stroke. Local endovascular therapy showed a significant improvement in functional independence versus standard care (odds ratio, 1.779; 95% confidence interval, 1.262-2.507; P < .001). This benefit strengthened further on subgroup analyses of trials in which a majority of cases used stent retrievers, trials with intravenous thrombolysis use in both arms when appropriate, and trials that required preprocedural imaging of all patients. There were no significant differences between arms in terms of mortality, hemicraniectomy, intracranial hemorrhage, and cerebral edema rates (P > .05). In conclusion, in the treatment of acute ischemic stroke, local endovascular therapy leads to improved functional independence compared with standard care.

JNIS podcasts: the early part of our journey

Podcasts are an area of innovation in the neurointerventional space that has the potential to convey information in ways that traditional journal articles in peer-reviewed journals do not. BMJ maintains an archive of all of its podcasts on the Journal of NeuroInterventional Surgery (JNIS) website. We sought to analyze this early JNIS podcast experience and assess the impact of content elements and an increased presence in social media.

The impact of evidence: evolving therapy for acute ischemic stroke in a large healthcare system

BACKGROUND

With a recent surge of clinical trials, the treatment of ischemic stroke has undergone dramatic changes.

OBJECTIVE

To evaluate the impact of evidence and a revamped stroke protocol on a large healthcare system.

METHODS

A retrospective review of 69 patients with ischemic stroke treated with intra-arterial therapy was carried out. Cohort 1 included patients treated before implementation of a new stroke protocol, and cohort 2 after implementation. Angiographic outcome was graded using the Thrombolysis in Cerebral Infarction (TICI) score. Clinical outcomes were assessed using the National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS).

RESULTS

Primary outcomes comparing cohorts demonstrated decreased arrival-to-puncture time (cohort 2: 104 vs cohort 1: 181 min, p<0.001), similar TICI 2b/3 rates (86.5% vs 81.3%, p=0.5530), and similar percentage of patients with discharge mRS 0-2 (18.9% vs 21.9%, p=0.7740). Notable secondary outcomes for cohort 2 included decreased puncture-to-first pass time (34 vs 53 min, p <0.001), increased TICI 3 rates (37.8% vs 18.8%, p=0.0290), a trend toward greater improvements in NIHSS on postoperative day 1 (6.8 vs 2.6, p=0.0980) and discharge (9.5 vs 6.7, p=0.1130), and a trend toward increased percentage of patients discharged with mRS 0-3 (48.6% vs 34.4%, p=0.3280 NS). There were similar rates of symptomatic intracerebral hemorrhage (10.8% vs 9.4%, p=0.9570) and death (10.8% vs 15.6%, p=0.5530).

CONCLUSIONS

An interdisciplinary and rapid response to the emergence of strong clinical evidence can result in dramatic changes in a large healthcare system.

Comparison of four different collateral scores in acute ischemic stroke by CT angiography

Purpose

Multiple scores have been described for the assessment of collateralization in acute ischemic stroke. Currently, there is no gold standard for collateral assessment by CT angiography (CTA). This study compared four frequently used collateral scores with regard to their correlation with early infarct core and mismatch ratio.

Methods

30 consecutive patients with acute occlusion of the M1 segment or terminal carotid artery were reviewed retrospectively. Collaterals were assessed using dynamic and also single-phase CTA according to grading systems by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), Alberta Stroke Program Early CT Score (ASPECTS) (on collaterals), Christoforidis et al and Miteff et al. The Christoforidis and ASITN/SIR scores, which were initially designed for conventional angiography, were adapted to be applicable to CTA. The scores were compared with respect to early infarct core and mismatch ratio in perfusion CT estimated by RAPID software using Spearman correlation.

Results

ASITN/SIR and ASPECTS collateral scores showed good correlation with early infarct core (rho=−0.696, p<0.001 and rho=−0.677, p<0.001) and mismatch ratio (rho=0.609, p<0.001 and rho=0.581, p<0.001). In contrast, the Christoforidis and Miteff scores correlated less well with infarct core (rho=0.245, p=0.191 and rho=−0.272, p=0.145, respectively) and mismatch ratio (rho=−0.329, p=0.075 and rho=0.279, p=0.135, respectively). ASPECTS and ASITN/SIR showed excellent cross-correlation (rho=0.901, p<0.001).

Conclusions

Compared with the Christoforidis and Miteff scores, the modified ASITN/SIR and ASPECTS collateral scores showed consistently higher correlation with the extent of early infarct core and mismatch volume. This is probably because these scores evaluate the extent and delay of vascular enhancement in the affected territory rather than the backflow of contrast medium to the occlusion.

A systematic review and meta-analysis of randomized controlled trials of endovascular thrombectomy compared with best medical treatment for acute ischemic stroke

BACKGROUND

Acute ischemic strokes involving occlusion of large vessels usually recanalize poorly following treatment with intravenous thrombolysis. Recent studies have shown higher recanalization and higher good outcome rates with endovascular therapy compared with best medical management alone. A systematic review and meta-analysis investigating the benefits of all randomized controlled trials of endovascular thrombectomy where at least 25% of patients were treated with a thrombectomy device for the treatment of acute ischemic stroke compared with best medical treatment have yet to be performed.

AIM

To perform a systematic review and a meta-analysis evaluating the effectiveness of endovascular thrombectomy compared with best medical care for treatment of acute ischemic stroke.

SUMMARY OF REVIEW

Our search identified 437 publications, from which eight studies (totaling 2423 patients) matched the inclusion criteria. Overall, endovascular thrombectomy was associated with improved functional outcomes (modified Rankin Scale 0-2) [odds ratio 1·56 (1·32-1·85), P < 0·00001]. There was a tendency toward decreased mortality [odds ratio 0·84 (0·67-1·05), P = 0·12], and symptomatic intracerebral hemorrhage was not increased [odds ratio 1·03 (0·71-1·49), P = 0·88] compared with best medical management alone. The odds ratio for a favorable functional outcome increased to 2·23 (1·77-2·81, P < 0·00001) when newer generation thrombectomy devices were used in greater than 50% of the cases in each trial.

CONCLUSIONS

There is clear evidence for improvement in functional independence with endovascular thrombectomy compared with standard medical care, suggesting that endovascular thrombectomy should be considered the standard effective treatment alongside thombolysis in eligible patients.

Effectiveness of regionalized systems for stroke and myocardial infarction

BACKGROUND

Acute ischemic stroke (AIS) and ST-segment elevation myocardial infarction (STEMI) are ischemic emergencies. Guidelines recommend care delivery within formally regionalized systems of care at designated centers, with bypass of nearby centers of lesser or no designation. We review the evidence of the effectiveness of regionalized systems in AIS and STEMI.

METHODS

Literature was searched using terms corresponding to designation of AIS and STEMI systems and from 2010 to the present. Inclusion criteria included report of an outcome on any dependent variable mentioned in the rationale for regionalization in the guidelines and an independent variable comparing care to a non- or pre-regionalized system. Designation was defined in the AIS case as certification by the Joint Commission as either a primary (PSC) or comprehensive (CSC) stroke center. In the STEMI case, the search was conducted linking "regionalization" and "myocardial infarction" or citation as a model system by any American Heart Association statement.

RESULTS

For AIS, 17 publications met these criteria and were selected for review. In the STEMI case, four publications met these criteria; the search was therefore expanded by relaxing the criteria to include any historical or anecdotal comparison to a pre- or nonregionalized state. The final yield was nine papers from six systems.

CONCLUSION

Although regionalized care results in enhanced process and reduced unadjusted rates of disparity in access and adverse outcomes, these differences tend to become nonsignificant when adjusted for delayed presentation and hospital arrival by means other than emergency medical services. The benefits of regionalized care occur along with a temporal trend of improvement due to uptake of quality initiatives and guideline recommendations by all systems regardless of designation. Further research is justified with a randomized registry or cluster randomized design to support or refute recommendations that regionalization should be the standard of care.

A collaborative sequential meta-analysis of individual patient data from randomized trials of endovascular therapy and tPA vs. tPA alone for acute ischemic stroke: ThRombEctomy And tPA (TREAT) analysis: statistical analysis plan for a sequential meta-analysis performed within the VISTA-Endovascular collaboration

Rationale

Endovascular treatment has been shown to restore blood flow effectively. Second-generation medical devices such as stent retrievers are now showing overwhelming efficacy in clinical trials, particularly in conjunction with intravenous recombinant tissue plasminogen activator.

Aims and Design

This statistical analysis plan utilizing a novel, sequential approach describes a prospective, individual patient data analysis of endovascular therapy in conjunction with intravenous recombinant tissue plasminogen activator agreed upon by the Thrombectomy and Tissue Plasminogen Activator Collaborative Group.

Study outcomes

This protocol will specify the primary outcome for efficacy, as ‘favorable’ outcome defined by the ordinal distribution of the modified Rankin Scale measured at three-months poststroke, but with modified Rankin Scales 5 and 6 collapsed into a single category. The primary analysis will aim to answer the questions: ‘what is the treatment effect of endovascular therapy with intravenous recombinant tissue plasminogen activator compared to intravenous tissue plasmi-nogen activator alone on full scale modified Rankin Scale at 3 months?’ and ‘to what extent do key patient characteristics influence the treatment effect of endovascular therapy?’. Key secondary outcomes include effect of endovascular therapy on death within 90 days; analyses of modified Rankin Scale using dichotomized methods; and effects of endovascular therapy on symptomatic intracranial hemorrhage. Several secondary analyses will be considered as well as expanding patient cohorts to intravenous recombinant tissue plasminogen activator-ineligible patients, should data allow.

Discussion

This collaborative meta-analysis of individual participant data from randomized trials of endovascular therapy vs. control in conjunction with intravenous thrombolysis will demonstrate the efficacy and generalizability of endovascular therapy with intravenous thrombolysis as a concomitant medication.

Endovascular stroke therapy with the Aperio thrombectomy device

BACKGROUND

The pharmaceutical therapy for acute ischemic stroke has shortcomings in reopening large vessels and dissolving long thrombi, and endovascular treatment has been found to provide added value. The Aperio thrombectomy device showed promising results in an experimental study. The purpose of this study was to evaluate the device clinically.

METHODS

119 patients with acute stroke were treated in nine centers using the Aperio thrombectomy device. Target vessel, diameter, thrombus length, procedure time, recanalization, number of deployments, additional use of anticoagulants, complications, and the use of additional devices were assessed.

RESULTS

The median thrombus length was 15 mm (range 1.5-20 mm) and the average time from device insertion to recanalization was 30 min (range 5-120 min). Blood flow restoration (Thrombolysis In Cerebral Infarction (TICI) 2-3) was achieved in 85%. In the majority of cases complete clot removal was achieved (TICI 0, 12%; TICI 1, 2%; TICI 2a, 14%; TICI 2b, 18%; TICI 3, 53%). The median number of deployments was 2 (range 1-6). Twelve procedural complications (10%) occurred.

CONCLUSIONS

The Aperio thrombectomy device seems to be an effective and adequately safe tool for reopening occluded cerebral arteries in the setting of acute stroke.

Improved clinical outcome 3 months after endovascular treatment, including thrombectomy, in patients with acute ischemic stroke: a meta-analysis

Background and purpose

Intravenous thrombolysis with tissue plasminogen activator is standard treatment in acute stroke today. The benefit of endovascular treatment has been questioned. Recently, studies evaluating endovascular treatment and intravenous thrombolysis compared with intravenous thrombolysis alone, have reported improved outcome for the intervention group. The aim of this study was to perform a meta-analysis of randomized controlled trials comparing endovascular treatment in addition to intravenous thrombolysis with intravenous thrombolysis alone.

Methods

Databases were searched for eligible randomized controlled trials. The primary outcome was a functional neurological outcome after 90 days. A secondary outcome was severe disability and death. Data were pooled in the control and intervention groups, and OR was calculated on an intention to treat basis with 95% CIs. Outcome heterogeneity was evaluated with Cochrane's Q test (significance level cut-off value at <0.10) and I² (significance cut-off value >50%) with the Mantel–Haenszel method for dichotomous outcomes. A p value <0.05 was regarded as statistically significant.

Results

Six studies met the eligibility criteria, and data from 1569 patients were analyzed. A higher probability of a functional neurological outcome after 90 days was found for the intervention group (OR 2, 95% CI 2 to 3). There was a significantly higher probability of death and severe disability in the control group compared with the intervention group.

Conclusions

Endovascular treatment in addition to intravenous thrombolysis for acute ischemic stroke leads to an improved clinical outcome after 3 months, compared with patients receiving intravenous thrombolysis alone.

Relationship Between Lesion Topology and Clinical Outcome in Anterior Circulation Large Vessel Occlusions

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) Alberta Stroke Program Early CT Score (ASPECTS), a surrogate of infarct volume, predicts outcome in anterior large vessel occlusion strokes. We aim to determine whether topological information captured by DWI ASPECTS contributes additional prognostic value.

METHODS

Adults with intracranial internal carotid artery, M1 or M2 middle carotid artery occlusions who underwent endovascular therapy were included. The primary outcome measure was poor clinical outcome (3-month modified Rankin Scale score, 3-6). Prognostic value of the 10 DWI ASPECTS regions in predicting poor outcome was determined by multivariable logistic regression, controlling for final infarct volume, age, and laterality.

RESULTS

Two hundred and thirteen patients (mean age, 66.1±14.5 years; median National Institutes of Health Stroke Scale, 15) were included. Inter-rater reliability was good for DWI ASPECTS (deep regions, κ=0.72; cortical regions, κ=0.63). All DWI ASPECTS regions with the exception of the putamen were significant predictors (P<0.05) of poor outcome in univariate analyses. Statistical collinearity among ASPECTS regions was not observed. Using penalized multivariable logistic regression, only M4 (odds ratio, 2.82; 95% confidence interval, 1.39-5.76) and M6 (odds ratio, 2.45; 95% confidence interval, 1.15-5.3) involvement were associated with poor outcome. M6 involvement independently predicted poor outcome in right hemispheric strokes (odds ratio, 5.8; 95% confidence interval, 1.9-20.3), whereas M4 (odds ratio, 4.3; 95% confidence interval, 1.3-15.0) involvement predicted poor outcome in left hemispheric strokes adjusting for infarct volume. Topologic information modestly improved the predictive ability of a prognostic score that incorporates age, infarct volume, and hemorrhagic transformation.

CONCLUSIONS

Involvement of the right parieto-occipital (M6) and left superior frontal (M4) regions affect clinical outcome in anterior large vessel occlusions over and above the effect of infarct volume and should be considered during prognostication.

Treatment of acute ischemic stroke: from fibrinolysis to neurointervention

Thrombolytic therapy with intravenous recombinant tissue plasminogen activator is well established as a beneficial treatment for patients presenting with acute ischemic stroke (AIS). The odds of a favorable clinical outcome (living independently) increase as the time between stroke onset and treatment with IV thrombolysis decreases. However, many patients present with a large clot burden that seldom responds to systemic fibrinolysis. Alternative options include new and emerging endovascular therapies that have recently proven effectiveness at restoring cerebral blood flow to the ischemic brain parenchyma. This review article will briefly outline some of the key evidence for intravenous thrombolysis as well as endovascular therapy for AIS.