Direct endovascular thrombectomy and bridging strategies for acute ischemic stroke: a network meta-analysis

Bridging therapy improves functional outcomes and reduces 90-day mortality compared with direct endovascular thrombectomy in patients with acute posterior ischemic stroke: a systematic review and meta-analysis

BACKGROUND

It remains unclear whether bridging therapy can achieve better neurologic outcomes than direct endovascular thrombectomy (EVT) in patients with posterior ischemic stroke.

METHODS

We systematically searched PubMed, EMBASE, and Cochrane databases with posterior artery occlusion treated with bridging therapy vs. EVT. Efficacy was assessed based on functional independence at 90 days and successful recanalization, whereas safety was assessed by mortality, rate of symptomatic intracranial hemorrhage (sICH), and occurrence of any hemorrhage. All data were analyzed with Review Manager software v5.3 and the risk of bias was determined using the Methodological Index for Non-randomized Studies.

RESULTS

We included 17 studies with a total of 3278 patients (1211 in the bridging therapy group and 2067 in the EVT group). Patients in the bridging group had a better functional outcome at 90 days, as evidenced by a higher proportion with a Modified Rankin Scale (mRS) score of 0-2 compared with the EVT group (odds ratio (OR) = 1.83, 95% confidence interval (CI): 1.54-2.19, P < 0.01), while no difference in mRS score of 0-3 (OR = 1.18, 95% CI: 0.96-1.45, P = 0.11). Patients in the bridging therapy group also had lower 90-day mortality rate (OR = 0.75, 95% CI: 0.59-0.95, P = 0.02). There were no significant differences between groups in rates of successful recanalization (OR = 0.96, 95% CI: 0.74-1.25, P = 0.77), sICH (OR = 1.27, 95% CI: 0.86-1.89, P = 0.24), and hemorrhage (OR = 1.22, 95% CI: 0.60-2.50, P = 0.58).

CONCLUSIONS

Among patients with posterior ischemic stroke, bridging therapy may be superior to EVT in achieving a good functional outcome and lowering the mortality without increasing the risks of hemorrhage.

Endovascular Thrombectomy With or Without Thrombolysis for Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

To this date, whether to administer intravenous thrombolysis (IVT) prior to endovascular thrombectomy (EVT) for stroke patients still stirs some debate. We aimed to systematically update the evidence from randomized trials comparing EVT alone vs EVT with bridging IVT.

Methods

We searched MEDLINE, EMBASE, and the Cochrane Library to identify randomized controlled trials (RCTs) comparing EVT with or without IVT in patients presenting with stroke secondary to a large vessel occlusion. We conducted meta-analyses using random-effects models to compare functional independence, mortality, and symptomatic intracranial hemorrhage (sICH), between EVT and EVT with IVT. We assessed risk of bias using the Cochrane risk-of-bias tool and certainty of evidence for each outcome using the GRADE approach.

Results

Of 11,111 citations, we included 6 studies with a total of 2336 participants. We found low-certainty evidence of possibly a small decrease in the proportion of patients with functional independence (risk difference [RD] -2.0%, 95% CI -5.9% to 2.0%), low-certainty evidence that there is possibly a small increase in mortality (RD 1.0%, 95% CI -2.2% to 4.7%), and moderate-certainty evidence that there is probably a decrease in sICH (RD -1.0%, 95% CI -1.6% to .7%) for patients with EVT alone compared to EVT plus IVT, respectively.

Conclusion

Low-certainty evidence shows that there is possibly a small decrease in functional independence, low-certainty evidence shows that there is possibly a small increase in mortality, and moderate-certainty evidence that there is probably a decrease in sICH for patients with EVT alone compared to EVT plus IVT.

Clinical evidence comparing bridging and direct endovascular thrombectomy: progress and controversies

Clinical evidence comparing bridging endovascular thrombectomy (bEVT) with intravenous thrombolysis and direct endovascular thrombectomy (dEVT) without thrombolysis for patients with acute ischemic stroke (AIS) presented directly to an EVT-capable center is overwhelming but inconsistent. This study aimed to analyze the progress and controversies in clinical evidence based on current meta-analyses. Three databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched. Relevant data were extracted and reviewed from the pooled studies. The Assessment of Multiple Systematic Review (AMSTAR-2) was used for quality assessment. Twenty-five meta-analyses were finally included. There were 56% (14/25) from Asian countries, 20% (5/25) from North America, and 24% (6/25) from Europe. The majority (72%, 18/25) of evidence arose in a short period from 2020 to 2022 with the serial publication of four randomized controlled trials (RCTs). Among the 25 meta-analyses, 11 pooled at least three RCTs but there is substantial overlap among seven (five recruited the same four RCTs solely and two recruited the same three RCTs solely). Meanwhile, quality rating based on AMSTAR-2 showed 16 'high' rated studies (64%). For functional independence, 40% (10/25) of studies favored bEVT and 60% showed neutral results. For symptomatic intracerebral hemorrhage, most studies (82.6%, 19/23) showed no significant difference. Non-RCT studies contributed to evidence favoring bEVT. Current RCTs provide an update of clinical evidence comparing bEVT and dEVT. However, they simultaneously contribute to an unnecessary overlap among studies. Contemporary observational studies demonstrated different but possibly confounded evidence. Thus, this issue still requires more clinical evidence under standard procedures.

Automatic Alberta Stroke Program Early Computed Tomographic Scoring in patients with acute ischemic stroke using diffusion-weighted imaging

Alberta Stroke Program Early Computed Tomographic Scoring (ASPECTS) is a reliable method for assessing early ischemic changes in the blood supply area of the middle cerebral artery in patients with acute ischemic stroke. This study aims to propose a deep learning based automatic evaluation strategy for DWI-ASPECTS to serve as a reference for clinicians in urgent decision making for endovascular thrombectomy. Ten ASPECTS regions are extracted from the DWI series to train the independent classification network for each region, the accurate training labels of which are confirmed by neuroradiologists. Two classical convolutional neural networks (VGG-16 and ResNet-50) are validated. Subsequently, the innovative CBAM-VGG is designed to improve the accurate scoring of four small-volume DWI-ASPECTS regions, including caudate nucleus, lenticular nucleus, internal capsule, and insular lobe. Average F1-score of 0.929 and 0.840 and the average accuracy of 94.75% and 84.99% are obtained when scoring on six cortical regions M1-M6 and four small ASPECTS regions, respectively. In addition, the modified algorithm CBAM-VGG shows a significant improvement in the accuracy of estimating the four ASPECTS regions with smaller volumes. The experimental results demonstrate that the deep learning methods facilitate the efficiency and robustness of automatic DWI-ASPECTS scoring, which can provide a reference for clinical decision-making.

Endovascular thrombectomy with or without thrombolysis bridging in patients with acute ischaemic stroke: protocol for a systematic review, meta-analysis of randomised trials and cost-effectiveness analysis

INTRODUCTION

Current published guidelines and meta-analyses comparing endovascular thrombectomy (EVT) alone versus EVT with bridging intravenous thrombolysis (IVT) suggest that EVT alone is non-inferior to EVT with bridging thrombolysis in achieving favourable functional outcome. Because of this controversy, we aimed to systematically update the evidence and meta-analyse data from randomised trials comparing EVT alone versus EVT with bridging thrombolysis, and performed an economic evaluation comparing both strategies.

METHODS AND ANALYSIS

We will conduct a systematic review of randomised controlled trials comparing EVT with or without bridging thrombolysis in patients presenting with large vessel occlusions. We will identify eligible studies by systematically searching the following databases from inception without any language restrictions: MEDLINE (through Ovid), Embase and the Cochrane Library. The following criteria will be used to assess eligibility for inclusion: (1) adult patients ≥18 years old; (2) randomised patients to EVT alone or to EVT with IVT; and (3) measured outcomes, including functional outcomes, at least 90 days after randomisation. Pairs of reviewers will independently screen the identified articles, extract information and assess the risk of bias of eligible studies. We will use the Cochrane Risk-of-Bias tool to evaluate risk of bias. We will also use the Grading of Recommendations, Assessment, Development and Evaluation approach to assess the certainty in evidence for each outcome. We will then perform an economic evaluation based on the extracted data.

ETHICS AND DISSEMINATION

This systematic review will not require a research ethics approval because no confidential patient data will be used. We will disseminate our findings by publishing the results in a peer-reviewed journal and via presentation at conferences.

PROSPERO REGISTRATION NUMBER

CRD42022315608.

Mechanical thrombectomy alone versus with thrombolysis for ischemic stroke: A meta-analysis of randomized trials

INTRODUCTION

Mechanical thrombectomy (MT) is the standard of care in eligible patients presenting with acute ischemic stroke (AIS). The question of whether intravenous thrombolysis (IVT) improves outcomes in conjunction with MT remains unanswered. We performed a systematic review and meta-analysis of published randomized controlled trials (RCT) to explore outcomes of MT with and without IVT.

METHODS

Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0-2, thrombolysis in cerebral infarction (TICI) score 2b-3, symptomatic intracranial hemorrhage (sICH), distal embolization, and mortality. We calculated pooled risk ratios (RRs) and their corresponding 95% confidence intervals (CI).

RESULTS

Six RCTs with 2334 patients compared outcomes of patients treated with MT alone and MT with IVT. Both treatments resulted in comparable rates of mRS 0-2 (RR = 0.96, 95% CI = 0.88-1.04; p-value = 0.282), sICH (RR = 0.80, 95% CI = 0.55-1.17; p-value = 0.253), mortality at 90-days (RR = 1.06, 95% CI = 0.88-1.28; p-value = 0.529), and distal embolization (RR = 1.10, 95% CI = 0.79-1.52; p-value = 0.572). MT alone was associated with a lower rate of TICI 2b-3 compared to MT with IVT (RR = 0.96, 95% CI = 0.93-0.99; p-value = 0.006).

CONCLUSIONS

In this meta-analysis of six RCTs, MT alone was comparable to MT plus IVT for mRS 0-2, sICH, mortality, and distal embolization; however, MT alone resulted in lower rates of TICI 2b-3. Further trials are needed to determine which patient populations benefit from MT plus IVT and to increase the power of future meta-analyses.

Efficacy and safety of endovascular treatment with or without intravenous alteplase in acute anterior circulation large vessel occlusion stroke: a meta-analysis of randomized controlled trials

OBJECTIVE

The current meta-analysis aimed to investigate the efficacy and safety of direct endovascular treatment (EVT) and bridging therapy (EVT with prior intravenous thrombolysis (IVT)) in patients with acute anterior circulation large vessel occlusion (LVO) stroke.

METHODS

This meta-analysis followed PRISMA guidelines. Eligible RCTs were identified through a systemic search of electronic databases (PubMed, Ovid, Web of Science, and Cochrane Library) from the inception dates to January 10, 2022. The pooled analyses were performed using RevMan 5.3 software. The primary outcome was functional outcome on the modified Rankin Scale (mRS) (range 0 to 5) at 90 days. The secondary outcomes included successful reperfusion, intracranial hemorrhage, and mortality (mRS 6) within 90 days.

RESULTS

A total of 4 RCTs involving 1633 patients were finally included. Findings of pooled analyses indicated that neither the primary outcomes (no disability (mRS 0), no significant disability despite some symptoms (mRS 1), slight disability (mRS 2), moderate disability (mRS 3), moderately severe disability (mRS 4), severe disability (mRS 5), excellent outcome (mRS 0-1), functional independence outcome (mRS 0-2), and poor outcome (mRS 3-5)) nor the secondary outcomes (successful reperfusion, intracranial hemorrhage, and mortality) in the EVT groups were not statistically significant compared with the IVT plus EVT groups (P > 0.05). In addition, the outcomes of sensitivity analysis implied that the findings of meta-analysis were credible.

CONCLUSIONS

Among patients with acute ischemic stroke due to LVO of anterior circulation, EVT alone yielded efficacy and safety outcomes similar to IVT plus EVT.

Effect of stroke etiology on endovascular thrombectomy with or without intravenous alteplase: a subgroup analysis of DIRECT-MT

BACKGROUND

Stroke etiology might influence the clinical outcomes in patients with large vessel occlusion receiving endovascular treatment (EVT) with or without thrombolysis.

OBJECTIVE

To examine whether stroke etiology resulted in different efficacy and safety in patients treated with EVT-alone or EVT preceded by intravenous alteplase (combined therapy).

METHODS

We assessed the efficacy and safety of treatment strategy based on prespecified stroke etiology, cardioembolism (CE), large-artery atherosclerosis (LAA), and undetermined cause (UC) for patients enrolled in the DIRECT-MT trial. The primary outcome was the modified Rankin Scale (mRS) score at 90 days. Multivariate ordinal logistic regression analysis was used to calculate the adjusted common OR for a shift of better mRS score for EVT-alone versus combined therapy. A term was entered to test for interaction.

RESULTS

In this study, 656 patients were grouped into three prespecified stroke etiologic subgroups. The adjusted common ORs for improvement in the 90-day ordinal mRS score with EVT-alone were 1.2 (95% CI 0.8 to 1.8) for CE, 1.6 (95% CI 0.8 to 3.3) for LAA, and 0.8 (95% CI 0.5 to 1.3) for UC. Compared with CE, EVT-alone was more likely to result in an mRS score of 0-1 (p_interaction=0.047) and extended Thrombolysis in Cerebral Infarction ≥2b (p_interaction=0.041) in the LAA group. The differences in mortality and symptomatic intracranial hemorrhage within 90 days were not significant between the subgroups (p＞0.05).

CONCLUSIONS

The results did not support the hypothesis that a specific treatment strategy based on stroke etiology should be used for patients with large vessel occlusion (NCT03469206).

Aspects of ischemic stroke biomechanics derived using ex-vivo and in-vitro methods relating to mechanical thrombectomy

Establishing the underlying biomechanics of acute ischemic stroke (AIS) and its treatment is fundamental to developing more effective clinical treatments for one of society's most impactful diseases. Recent changes in AIS management, driven by clinical evidence of improved treatments, has already led to a rapid rate of innovation, which is likely to be sustained for many years to come. These unprecedented AIS triage and treatment innovations provide a great opportunity to better understand the disease. In this article we provide a perspective on the recreation of AIS in the laboratory to inform contemporary device design and procedural techniques in mechanical thrombectomy. Presentation of these findings, which have been used to solve the applied problem of designing mechanical thrombectomy devices, is intended to help inform the development of basic biomechanics solutions for AIS.

Bridging thrombolysis in atrial fibrillation stroke is associated with increased hemorrhagic complications without improved outcomes

BACKGROUND

Atrial fibrillation (AF) associated ischemic stroke is associated with worse functional outcomes, less effective recanalization, and increased rates of hemorrhagic complications after intravenous thrombolysis (IVT). Conversely, AF is not associated with hemorrhagic complications or functional outcomes in patients undergoing mechanical thrombectomy (MT). This differential effect of MT and IVT in AF associated stroke raises the question of whether bridging thrombolysis increases hemorrhagic complications in AF patients undergoing MT.

METHODS

This international cohort study of 22 comprehensive stroke centers analyzed patients with large vessel occlusion (LVO) undergoing MT between June 1, 2015 and December 31, 2020. Patients were divided into four groups based on comorbid AF and IVT exposure. Baseline patient characteristics, complications, and outcomes were reported and compared.

RESULTS

6461 patients underwent MT for LVO. 2311 (35.8%) patients had comorbid AF. In non-AF patients, bridging therapy improved the odds of good 90 day functional outcomes (adjusted OR (aOR) 1.29, 95% CI 1.03 to 1.60, p=0.025) and did not increase hemorrhagic complications. In AF patients, bridging therapy led to significant increases in symptomatic intracranial hemorrhage and parenchymal hematoma type 2 (aOR 1.66, 1.07 to 2.57, p=0.024) without any benefit in 90 day functional outcomes. Similar findings were noted in a separate propensity score analysis.

CONCLUSION

In this large thrombectomy registry, AF patients exposed to IVT before MT had increased hemorrhagic complications without improved functional outcomes, in contrast with non-AF patients. Prospective trials are warranted to assess whether AF patients represent a subgroup of LVO patients who may benefit from a direct to thrombectomy approach at thrombectomy capable centers.

'Drip-and-ship' intravenous thrombolysis and outcomes for large vessel occlusion thrombectomy candidates in a hub-and-spoke telestroke model

BACKGROUND

Randomized trials have not demonstrated benefit from intravenous thrombolysis among patients undergoing endovascular thrombectomy (EVT). However, these trials included primarily patients presenting directly to an EVT capable hub center. We sought to study outcomes for EVT candidates who presented to spoke hospitals and were subsequently transferred for EVT consideration, comparing those administered alteplase at spokes (i.e., 'drip-and-ship' model) versus those not.

METHODS

Consecutive EVT candidates presenting to 25 spokes from 2018 to 2020 with pre-transfer CT angiography defined emergent large vessel occlusion and Alberta Stroke Program CT score ≥6 were identified from a prospectively maintained Telestroke database. Outcomes of interest included adequate reperfusion (Thrombolysis in Cerebral Infarction (TICI) 2b-3), intracerebral hemorrhage (ICH), discharge functional independence (modified Rankin Scale (mRS) ≤2), and 90 day functional independence.

RESULTS

Among 258 patients, median age was 70 years (IQR 60-81), median National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-19), and 50% were women. Ninety-eight (38%) were treated with alteplase at spokes and 113 (44%) underwent EVT at the hub. Spoke alteplase use independently increased the odds of discharge mRS ≤2 (adjusted OR 2.43, 95% CI 1.08 to 5.46, p=0.03) and 90 day mRS ≤2 (adjusted OR 3.45, 95% CI 1.65 to 7.22, p=0.001), even when controlling for last known well, NIHSS, and EVT; it was not associated with an increased risk of ICH (OR 1.04, 95% CI 0.39 to 2.78, p=0.94), and there was a trend toward association with greater TICI 2b-3 (OR 3.59, 95% CI 0.94 to 13.70, p=0.06).

CONCLUSIONS

Intravenous alteplase at spoke hospitals may improve discharge and 90 day mRS and should not be withheld from EVT eligible patients who first present at alteplase capable spoke hospitals that do not perform EVT. Additional studies are warranted to confirm and further explore these benefits.

Endovascular thrombectomy without versus with intravenous thrombolysis in acute ischemic stroke: a non-inferiority meta-analysis of randomized clinical trials

OBJECTIVE

To conduct a meta-analysis of randomized trials to comprehensively compare the effect of endovascular thrombectomy (EVT) versus intravenous thrombolysis (IVT) plus EVT on functional independence (modified Rankin Scale (mRS) 0-2) after acute ischemic stroke due to large vessel occlusions (AIS-LVO).

METHODS

We searched Pubmed, EMBASE, CENTRAL, and clinicaltrials.gov from January 2000 to February 2021 and abstracts presented at the International Stroke Conference in March 2021 to identify trials comparing EVT alone versus IVT plus EVT in AIS-LVO. Five non-inferiority margins established in the literature were assessed: -15%, -10%, -6.5%, -5%, and -1.3% for the risk difference for functional independence at 90 days.

RESULTS

Four trials met the selection criteria, enrolling 1633 individuals, with 817 participants randomly assigned to EVT alone and 816 to IVT plus EVT. Crude cumulative rates of 90-day functional independence were 46.0% with EVT alone versus 45.5% with IVT plus EVT. Pooled results showed the risk difference of functional independence was 1% (95% CI -4% to 5%) between EVT alone versus IVT plus EVT. The lower 95% CI bound of -4% fell within the non-inferiority margins of -15%, -10%, -6.5%, and -5%, but not -1.3%. Pooled results also showed the risk difference between EVT alone versus IVT plus EVT was 1% (95% CI -3% to 5%) for mRS 0-1, and 1% (95% CI -1% to 3%) for symptomatic intracranial hemorrhage.

CONCLUSIONS

This meta-analysis suggests that EVT alone is non-inferior to IVT plus EVT for several, but not the most stringent, non-inferiority margins.

Direct versus Bridging Mechanical Thrombectomy in Elderly Patients with Acute Large Vessel Occlusion: A Multicenter Cohort Study

Purpose

Elderly people represent a growing stroke population with different pathophysiological states than younger. Whether intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) is beneficial for elderly patients remains unclear. This study compared the efficacy and safety between elderly patients treated with MT alone and those treated with both IVT and MT.

Patients and Methods

Patients aged ≥65 years who were eligible for IVT within 4.5 h from symptom onset were selected from the ANGEL-ACT (Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemic Stroke) registry, a prospective registry program for patients with endovascular treatment from 111 Chinese stroke centers. The primary efficacy outcome was the 90-day modified Rankin Scale score. We compared efficacy and safety outcomes using ordinal or binary logistic regression or a generalized linear model.

Results

In total, 482 elderly patients were included: 187 (38.8%) received IVT and MT (bridging MT) and 295 (61.2%) received MT alone (direct MT). There was no significant difference in the 90-day modified Rankin Scale score between the two groups (median: 4 vs 4 points, respectively; adjusted β=−0.048, P=0.822). The direct MT group had a shorter onset-to-puncture time (225 vs 255 min, respectively; adjusted β=−55.074, P=0.002) and a lower rate of parenchymal hemorrhage type 2 within 24 h (2.80% vs 6.63%, respectively; adjusted odds ratio [OR]=0.287, 95% confidence interval [CI]=0.096–0.856, P=0.025). In addition, the direct MT group showed a trend toward a lower incidence of sICH (5.67% vs 10.06%, adjusted OR=0.453, P=0.061), procedure-related complications (7.12% vs 12.30%, adjusted OR=0.499, P=0.052) and distal or new territorial embolization (4.07% vs 6.95%, adjusted OR=0.450, P=0.093).

Conclusion

Direct MT had similar efficacy to bridging MT in terms of the 90-day functional outcome in elderly patients, whereas bridging MT had a longer onset-to-puncture time and increased risk of hemorrhagic transformation and procedure-related complications.

Is concurrent intravenous alteplase in patients undergoing endovascular treatment for large vessel occlusion stroke cost-effective even if the cost of alteplase is only US$1?

BACKGROUND

The added value of intravenous (IV) alteplase in large vessel occlusion (LVO) stroke over and beyond endovascular treatment (EVT) is controversial. We compared the long-term costs and cost-effectiveness of a direct-to-EVT paradigm in LVO stroke patients presenting directly to the mothership hospital to concurrent EVT and IV alteplase.

METHODS

We used a decision model consisting of a short-run model to analyze costs and functional outcomes within 90 days after the index stroke and a long-run Markov state transition model (cycle length of 12 months) to estimate expected lifetime costs and outcomes. Outcome data were from the DIRECT-MT trial (NCT03469206). Incremental cost-effectiveness ratios and net monetary benefits were calculated and probabilistic sensitivity analysis was performed. Analysis was performed from a healthcare perspective and a societal perspective using both a minimal assumed alteplase cost of US$1 and true alteplase cost.

RESULTS

When assuming a minimal cost of alteplase of $1, EVT with concurrent IV alteplase resulted in incremental lifetime cost of $5664 (healthcare perspective)/$4804 (societal perspective) and a decrement of 0.25 quality-adjusted life years (QALYs) compared with EVT only, indicating dominance of the EVT only approach. Net monetary benefits were consistently higher for EVT only compared with EVT with concurrent alteplase. Probabilistic sensitivity analysis showed increased costs without an increase in QALYs for EVT and concurrent IV alteplase compared with EVT only. Results were even more in favor of EVT when the true cost of alteplase was used for analysis.

CONCLUSION

EVT without concurrent alteplase is the preferred strategy from a health economic standpoint.

Direct mechanical thrombectomy without intravenous thrombolysis versus bridging therapy for acute ischemic stroke: A meta-analysis of randomized controlled trials

BACKGROUND

Direct mechanical thrombectomy may result in similar outcomes compared to a bridging approach with intravenous thrombolysis (IVT + MT) in acute ischemic stroke. Recent randomized controlled trials have varied in their design and noninferiority margin.

AIM

We sought to meta-analyze accumulated trial data to assess the difference and non-inferiority in clinical and procedural outcomes between direct mechanical thrombectomy and bridging therapy.

SUMMARY OF REVIEW

We conducted a systematic review of electronic databases following the preferred reporting items for systematic reviews and meta-analyses guidelines. Random effects meta-analyses were conducted for the pooled data. The primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) ≤ 2). Secondary outcomes included excellent functional outcome (mRS ≤ 1), mortality, any intracranial hemorrhage, symptomatic intracranial hemorrhage, successful reperfusion (thrombolysis in cerebral infarction ≥ 2 b), and procedure-related complications. Four randomized controlled trials comprising 1633 patients (817 direct mechanical thrombectomy, 816 bridging therapy) were included. There were no statistical differences for the 90-day good functional outcome (OR = 1.02, 95% CI 0.84-1.25, p = 0.54, I²= 0%), and the absolute risk difference was 1% (95% CI: -4% to 5%). The lower 95% CI falls within the strictest noninferiority margin of -10% among included randomized control trials. Direct mechanical thrombectomy reduced the odds of successful reperfusion (OR = 0.76, 95% CI: 0.60-0.97, p = 0.03, I²= 0%) and any intracranial hemorrhage (OR = 0.65, 95% CI: 0.49-0.86, p = 0.003, I²= 38%). There was no difference in the remaining secondary outcomes. The risk of bias for all studies was low.

CONCLUSION

The combined trial data assessing direct mechanical thrombectomy versus bridging therapy showed no difference in improving good functional outcome. The wide noninferiority thresholds set by individual trials are in contrast with the clinical consensus on minimally important differences. However, our pooled analysis indicates noninferiority of direct mechanical thrombectomy with a 4% margin of confidence. The application of these findings is limited to patients presenting directly to mechanical thrombectomy-capable centers and real-world workflow times may differ against those achieved in a trial setting.

Influence of intravenous alteplase on endovascular treatment decision-making in acute ischemic stroke due to primary medium-vessel occlusion: a case-based survey study

Background

Intravenous alteplase is currently the only evidence-based treatment for medium-vessel occlusion stroke (MeVO; M2/3, A2/3, and P2/3 vessel segment occlusions), but due to its limited efficacy, endovascular treatment (EVT) is increasingly performed in these patients. In this case-based survey study, we examined the influence of intravenous alteplase treatment on physicians’ decision-making for EVT in primary MeVO stroke.

Methods

In an international web-based survey among physicians involved in acute stroke care, participants provided their EVT decision for six quasi-identical fictional MeVO case scenarios (three with and without intravenous alteplase administered). Each scenario showed radiological images and clinical information in the form of a short case vignette. We compared EVT decisions (“immediate EVT”, “no EVT”, or “wait for alteplase effect” [in case scenarios with alteplase treatment only]) for case scenarios with and without alteplase treatment. Clustered multivariable logistic regression was performed to assess the effect of alteplase on treatment decision.

Results

The survey was completed by 366 physicians from 44 countries, resulting in 2196 responses included in this study. In alteplase-treated cases, 641/1098 (58.4%) responses favored immediate EVT, (279/1098 [25.4%]) favored no EVT and 178/1098 (16.2%) opted to wait for alteplase effect. In non-alteplase-treated case scenarios, 846/1098 (78.7%) were in favor of and 252/1098 (21.3%) against EVT. Intravenous alteplase was associated with a lower chance of a decision in favor of immediate EVT (adjusted OR 0.38 [95%CI 0.31 to 0.46]).

Conclusions

Intravenous alteplase is an important factor in EVT decision-making for MeVO stroke. However, even in alteplase-treated patients, more than half of the physicians decided to proceed with EVT without waiting for alteplase effect.

Extracellular Vesicle Application as a Novel Therapeutic Strategy for Ischemic Stroke

Ischemic stroke (IS) accounts for most of the cases of stroke onset, and due to short therapeutic time window for thrombolysis and numerous limited treatment measures and contraindications, lots of patients cannot receive satisfying therapeutic effects resulting in high disability and mortality worldly. In recent years, extracellular vesicles (EVs), as nanosized membrane-structured vesicles secreted from almost all cells, especially from stem/progenitor cells, have been reported to exert significant beneficial effects on IS from multiple approaches and notably ameliorate neurological outcome. Moreover, based on nano-size and lipid bilayer structure, EVs can easily penetrate the blood-brain barrier and migrate into the brain. In this review, we mainly systematically summarize the therapeutic effects of EVs on IS and explore their potential applications. Simultaneously, we also discuss administration routines, dosages, experimental observation time, and some key issues of EV application during IS treatment. It contributes to a comprehensive understanding of the progress of EV treatment for IS and providing confident evidence for further EV clinical application widely.

Trends of Acute Ischemic Stroke Reperfusion Therapies from 2012 to 2016 in the United States

BACKGROUND

American Heart Association/American Stroke Association guidelines recommend endovascular stroke therapy (EST) with recombinant tissue plasminogen activator (rt-PA) for eligible patients in acute ischemic stroke (AIS). Using the National Inpatient Sample database, we evaluated trends in treatment with rt-PA and EST for AIS and their outcomes.

METHODS

This is a cross-sectional observational study of patients with AIS admitted in US hospitals from 2012 to 2016. Patients were grouped into those who received rt-PA alone, EST alone, and rtPA+EST. Survey statistical procedures were performed. Multivariable regression analysis with pairwise comparisons of each treatment group with no treatment group was performed for discharge outcomes.

RESULTS

The study included 2,290,520 patients with AIS with the mean age of 70.46 years. Treatment rates increased from 2012 to 2016 for rt-PA by 7% per year (5.86%-7.67%, odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.05-1.08) and EST by 38% per year (0.55%-1.75%, OR = 1.38, 95% CI: 1.31-1.45) but not rt-PA+EST (0.54%-0.57%, OR = 1.04, 95% CI: 0.99-1.08). The mean length of stay reduced from 2012 to 2016 for rt-PA (6.07-4.91 days, P < 0.0001) and rt-PA+EST (9.19-7.10 days, P = 0.0067) but not for EST (9.61-8.51 days, P = 0.5074). The odds of patients discharged home increased by 8%, 9%, and 15% among patients who received rt-PA alone, EST alone, and rt-PA+EST, respectively, compared with no treatment group.

CONCLUSION

The utilization of rt-PA alone and EST alone increased but that of rt-PA+EST remained unchanged from 2012 to 2016 in the National Inpatient Sample.

Bridging Therapy and Occlusion Site Influence Symptomatic Hemorrhage Rate after Thrombectomy: A Daily Practice Study in 623 Stroke Patients

BACKGROUND

Comparison of symptomatic intracranial hemorrhage (SICH) rates between stroke patients treated with bridging therapy (BT) and primary mechanical thrombectomy (PMT) are scarce and difficult to interpret due to baseline differences between both populations.

METHODS

Retrospective analysis of patients with acute ischemic stroke treated with endovascular therapy (BT or PMT) was performed at our center between January 2010 and June 2017.

RESULTS

Six hundred twenty-three patients were included. Global SICH rate was 9% overall: 6.8% in the PMT group and 12.6% in the BT group. The following factors significantly associated with SICH after multivariate analysis: MCA occlusion (p: 0.047), stroke of unknown origin (p: 0.025), BT (p: 0.024), and procedural time over 65 min (p: 0.027). The following variables presented a statistically significant higher frequency in patients treated with PMT: atrial fibrillation (p: 0.005), anticoagulant medication (p < 0.001), wake-up strokes (p < 0.001), atherothrombotic etiology (p < 0.05), combined thrombectomy technique (p: 0.008), longer procedural times (p: 0.025), and favorable outcome at 3 months (p: 0.011). The following variables presented a statistically significant higher frequency in patients treated with BT: antiplatelet medication (p: 0.048), MCA occlusions (p: 0.017), cardioembolic etiology (p < 0.05), stent retriever/aspiration technique (p: 0.008), and SICH (p: 0.013). Patients with MCA occlusions had twice the risk of SICH after BT than after PMT (16.4 and 8.6%, p: 0.038).

CONCLUSIONS

In this clinical series, the SICH rate was higher in patients treated with BT than in those treated with PMT. Relevant differences in baseline (related to IVT contraindications) were found between both groups. Randomized studies of BT versus PMT in populations with similar baseline characteristics might be of interest.

Predictors for Failure of Early Neurological Improvement After Successful Thrombectomy in the Anterior Circulation

BACKGROUND AND PURPOSE

Failure of early neurological improvement (fENI) despite successful mechanical thrombectomy in the anterior circulation is a clinically frequent occurrence. Purpose of this analysis was to define independent clinical, radiological, laboratory, or procedural predictors for fENI.

METHODS

Retrospective single-center analysis of patients treated for acute ischemic stroke in the anterior circulation ensuing successful mechanical thrombectomy between January 2014 and April 2019. Patients were compared according to fENI (equal or higher National Institutes of Health Stroke Scale) and ENI (lower National Institutes of Health Stroke Scale at discharge). Thirty-eight variables were examined in multivariable analysis for association with fENI.

RESULTS

Five hundred forty-nine out of 1146 patients experienced successful recanalization (modified Treatment in Cerebral Ischemia 2c-3). fENI occurred in 115/549 (20.9%) patients. Independent predictors of fENI were premorbid modified Rankin Scale (odds ratio [OR] per point [IC], 1.21 [1.00-1.46], P=0.049), end-stage renal failure (OR [IC], 12.18 [2.01-73.63], P=0.007), admission glucose (OR [IC], 1.018 [1.004-1.013] per mg/dL, P=0.001), bridging IV lysis (OR [IC], 0.57 [0.35-0.93], P: 0.024), time from groin puncture to final recanalization (OR [IC], 1.004 [1.001-1.007] per minute, P=0.015), general anesthesia during mechanical thrombectomy (OR, 2.41 [1.43-4.08], P<0.001), symptomatic intracranial hemorrhage (OR [CI], 6.81 [1.84-25.16], P=0.004), and follow-up Alberta Stroke Program Early CT Score (OR [IC], 0.76 [0.69-0.84] per point, P<0.001). In a secondary analysis, involvement of the regions internal capsule, M4 and M5 (motor cortex) were further independent predictors for fENI. Patients with ENI were more likely to experience a good outcome (modified Rankin Scale on day 90, 0-2: n=229/435 [52.8%] versus n=13/115 [11.3%]; P<0.001).

CONCLUSIONS

The extent of infarction and the involvement of motor cortex and internal capsule as well as higher premorbid modified Rankin Scale, end-stage renal failure, high glucose level on admission, absence of bridging IV lysis, general anesthesia, and a longer therapy interval are presumably independent predictors for fENI in patients with successful mechanical thrombectomy.

Effect of Mechanical Thrombectomy Without vs With Intravenous Thrombolysis on Functional Outcome Among Patients With Acute Ischemic Stroke: The SKIP Randomized Clinical Trial

IMPORTANCE

Whether intravenous thrombolysis is needed in combination with mechanical thrombectomy in patients with acute large vessel occlusion stroke is unclear.

OBJECTIVE

To examine whether mechanical thrombectomy alone is noninferior to combined intravenous thrombolysis plus mechanical thrombectomy for favorable poststroke outcome.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, multicenter, randomized, open-label, noninferiority clinical trial in 204 patients with acute ischemic stroke due to large vessel occlusion enrolled at 23 hospital networks in Japan from January 1, 2017, to July 31, 2019, with final follow-up on October 31, 2019.

INTERVENTIONS

Patients were randomly assigned to mechanical thrombectomy alone (n = 101) or combined intravenous thrombolysis (alteplase at a 0.6-mg/kg dose) plus mechanical thrombectomy (n = 103).

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was a favorable outcome defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 2 at 90 days, with a noninferiority margin odds ratio of 0.74, assessed using a 1-sided significance threshold of .025 (97.5% CI). There were 7 prespecified secondary efficacy end points, including mortality by day 90. There were 4 prespecified safety end points, including any intracerebral hemorrhage and symptomatic intracerebral hemorrhage within 36 hours.

RESULTS

Among 204 patients (median age, 74 years; 62.7% men; median National Institutes of Health Stroke Scale score, 18), all patients completed the trial. Favorable outcome occurred in 60 patients (59.4%) in the mechanical thrombectomy alone group and 59 patients (57.3%) in the combined intravenous thrombolysis plus mechanical thrombectomy group, with no significant between-group difference (difference, 2.1% [1-sided 97.5% CI, -11.4% to ∞]; odds ratio, 1.09 [1-sided 97.5% CI, 0.63 to ∞]; P = .18 for noninferiority). Among the 7 secondary efficacy end points and 4 safety end points, 10 were not significantly different, including mortality at 90 days (8 [7.9%] vs 9 [8.7%]; difference, -0.8% [95% CI, -9.5% to 7.8%]; odds ratio, 0.90 [95% CI, 0.33 to 2.43]; P > .99). Any intracerebral hemorrhage was observed less frequently in the mechanical thrombectomy alone group than in the combined group (34 [33.7%] vs 52 [50.5%]; difference, -16.8% [95% CI, -32.1% to -1.6%]; odds ratio, 0.50 [95% CI, 0.28 to 0.88]; P = .02). Symptomatic intracerebral hemorrhage was not significantly different between groups (6 [5.9%] vs 8 [7.7%]; difference, -1.8% [95% CI, -9.7% to 6.1%]; odds ratio, 0.75 [95% CI, 0.25 to 2.24]; P = .78).

CONCLUSIONS AND RELEVANCE

Among patients with acute large vessel occlusion stroke, mechanical thrombectomy alone, compared with combined intravenous thrombolysis plus mechanical thrombectomy, failed to demonstrate noninferiority regarding favorable functional outcome. However, the wide confidence intervals around the effect estimate also did not allow a conclusion of inferiority.

TRIAL REGISTRATION

umin.ac.jp/ctr Identifier: UMIN000021488.

Impact of bridging thrombolysis on clinical outcome in stroke patients undergoing endovascular thrombectomy: a retrospective analysis of a regional stroke registry

Purpose

It is unclear whether stroke patients undergoing endovascular thrombectomy (EVT) should receive bridging intravenous thrombolysis (IVT), if eligible. This study aims at analyzing the impact of bridging IVT on short-term clinical outcome.

Methods

In a prospective regional stroke registry, all stroke patients with premorbid modified Rankin Scale (mRS) score of 0–2 who were admitted within 4.5 h after onset and treated with EVT were analyzed retrospectively. Patients receiving “IVT prior to EVT” (IVEVT) were compared to those undergoing “EVT only” regarding the ratio of good outcome, discharge mRS, mRS shift, hospital mortality, and occurrence of symptomatic intracranial hemorrhage.

Results

In total, 2022 patients were included, 816 patients (40.4%) achieved good clinical outcome; 1293 patients (63.9%) received bridging IVT. There was no significant difference between both groups regarding the ratio of good outcome (IVEVT 41.4% vs. EVT 38.5%, P = 0.231), discharge mRS (median, IVEVT 3 vs. EVT 3, P = 0.178), mRS shift (median, IVEVT 3 vs. EVT 3, P = 0.960), and hospital mortality (IVEVT 19.3% vs. EVT 19.5%, P = 0.984). Bridging IVT was not a predictor of outcome (adjusted OR 1.00, 95% CI 0.79–1.26, P = 0.979). However, it was an independent predictor of symptomatic intracranial hemorrhage (adjusted OR 1.79, 95% CI 1.21–2.72, P = 0.005).

Conclusions

The results of the present study suggest that bridging IVT does not seem to improve short-term clinical outcome of patients undergoing EVT. Nonetheless, there might be a subgroup of patients that benefits from IVT. This needs to be addressed in randomized controlled trials.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00234-020-02619-1.

Absent filling of the superficial middle cerebral vein is associated with reperfusion but not parenchymal hematoma in stroke patients undergoing thrombectomy: an observational study

Background

Parenchymal hematoma (PH) is the most feared complication of reperfusion therapy after stroke. The opacification of the superficial middle cerebral vein (SMCV) on computed tomography perfusion (CTP) has been associated with poor functional outcomes after stroke, while its association with PH has not been verified for acute stroke patients undergoing thrombectomy.

Methods

Consecutive patients with acute anterior large artery occlusion (LAO) who received thrombectomy were retrospectively enrolled between May 2018 and May 2019. Absent filing of the SMCV (SMCV−) on CTP-derived CT angiography was defined as no contrast filling of the SMCV across the whole venous phase in the ischemic hemisphere, while SMCV+ was defined as the presence of contrast filling of the SMCV at any time point of the venous phase.

Results

A total of 52 patients were enrolled in the study, and 15 patients (28.8%) developed a PH within 48 hours after thrombectomy. SMCV− was not associated with PH in both the univariate and multivariate logistic regression analyses (all P>0.05), but was an independent risk factor for reperfusion [modified thrombolysis in cerebral infarction score of 2b-3; odds ratio (OR) =0.172, 95% confidence interval (CI): 0.031–0.960, P=0.045]. Reperfusion was associated with a reduced risk of PH (OR =0.110, 95% CI: 0.013–0.913, P=0.041). However, in a subgroup analysis of patients who had reperfusion, the SMCV− group had a higher rate of PH than the SMCV+ group (40.0% vs. 13.8%, P=0.049).

Conclusions

In patients who received thrombectomy, SMCV− did not predict PH, but was a risk factor for reperfusion. Although reperfusion was a protective factor for PH, the SMCV− group was still at a higher risk of PH compared with the SMCV+ group when reperfusion was successfully achieved.

Efficacy and Safety of Recanalization Therapy for Acute Ischemic Stroke With Large Vessel Occlusion

Background and Purpose:

The optimal recanalization strategy for acute ischemic stroke with large vessel occlusion continues to be an area of active interest. Network meta-analysis can provide insight when direct comparative evidence is lacking.

Methods:

A systematic review of the literature using PubMed, Embase, the Cochrane Central Register of Controlled Trials, and SinoMed was performed, and a search was conducted for clinical trials on ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and StrokeCenter.org. Four independent reviewers conducted the study selection, data abstraction, and quality assessments.

Results:

The literature review identified 17 trials including 3236 patients and 8 ongoing clinical trials. Sample sizes ranged from 7 to 656 participants. Intravenous thrombolysis (IVT) was the most common intervention, followed by IVT plus mechanical thrombectomy (MT), IVT plus intraarterial thrombolysis, intraarterial thrombolysis alone, and MT alone. In the pooled network meta-analysis, IVT+MT was associated with a higher rate of independent functioning. In contrast, IVT was ranked as the most ineffective treatment strategy with respect to neurological functions, while direct MT was ranked as the least safe intervention with respect to all-cause mortality. Also, irrespective of assessment tools, endovascular treatment plus IVT led to higher successful recanalization rate than thrombolysis alone.

Conclusions:

Compared with other recanalization treatments, IVT+MT seems to be the most effective strategy, without increasing detrimental effects, for thrombolysis-eligible patients with large vessel occlusion-acute ischemic stroke. To improve the current evidentiary basis for recanalization treatment, future trials and real-world studies are warranted and should use unified definitions of symptomatic intracranial hemorrhage and recanalization.

Relationship between homocysteine level and prognosis of elderly patients with acute ischemic stroke treated by thrombolysis with recombinant tissue plasminogen activator

BACKGROUND

Acute ischemic stroke (AIS) is mainly caused by cerebral blood flow disorders, which further leads to ischemic brain necrosis or encephalomalacia. The role of homocysteine (Hcy), an independent risk factor for cardiovascular disease, in the development of atherosclerosis is gradually revealed. However, studies are still rare and little is known about the relationship of Hcy level with the prognosis.

AIM

To explore the relationship between Hcy level and prognosis in elderly patients with AIS after thrombolytic therapy with recombinant tissue plasminogen activator (rtPA).

METHODS

A total of 120 patients with acute ischemic stroke who were admitted to Jingzhou Central Hospital and underwent recombinant tissue plasminogen activator treatment were randomly selected from January 2017 to December 2018. They were divided into two groups according to the level of Hcy, with 60 patients in each group. Patients with Hcy ≥ 18.54 umol/L were included into a high-level group and those with Hcy < 18.54 umol/L were included into a low-level group. The outcomes were analyzed in the two groups after the treatment.

RESULTS

The National institute of Health Stroke Scale (NIHSS) scores were significantly higher in the high-level group than in the low-level group before and 1 h after the treatment (P < 0.05). There was no significant difference in NIHSS scores between the two groups at 12 and 24 h after the treatment (P > 0.05). The Modified Rankin scale (MRS) scores were significantly higher in the high-level group than in the low-level group before and 1 h after the treatment (P < 0.05). There was no significant difference in MRS scores between the two groups at 12 and 24 h after the treatment (P > 0.05). NIHSS and MRS scores were positively correlated with the prognosis after thrombolytic therapy (P < 0.05).

CONCLUSION

The level of Hcy is closely related to the prognosis of elderly patients with acute ischemic stroke, and after rtPA treatment, the prognosis of elderly patients is improved significantly.

Intravenous thrombolysis prior to mechanical thrombectomy in large vessel occlusions

OBJECTIVE

The substantial clinical improvement in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT), combined with the poor response of proximal intracranial occlusions to intravenous thrombolysis (IVT), led to questions regarding the utility of bridging therapy (BT; IVT followed by MT) compared to direct mechanical thrombectomy (dMT) for AIS patients with large vessel occlusion (LVO).

METHODS

We aimed to investigate the comparative safety and efficacy of BT and dMT in AIS patients. We included all observational studies and post hoc analyses from randomized controlled clinical trials that provided data on the outcomes of AIS patients with LVO stratified by IVT treatment status prior to MT.

RESULTS

We identified 38 eligible observational studies (11,798 LVO patients, mean age = 68 years, 56% treated with BT). In unadjusted analyses, BT was associated with a higher likelihood of 3-month functional independence (odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.32-1.76), 3-month functional improvement (common OR [cOR] for 1-point decrease in modified Rankin Scale score = 1.52, 95% CI = 1.18-1.97), early neurological improvement (OR = 1.21, 95% CI = 1.83-1.76), successful recanalization (OR = 1.22, 95% CI = 1.02-1.46), and successful recanalization with ≤2 device passes (OR = 2.28, 95% CI = 1.43-3.64) compared to dMT. BT was also related to a lower likelihood of 3-month mortality (OR = 0.64, 95% CI = 0.57-0.73). In the adjusted analyses, BT was independently associated with a higher likelihood of 3-month functional independence (adjusted OR = 1.55, 95% CI = 1.26-1.91) and lower odds of 3-month mortality (adjusted OR = 0.80, 95% CI = 0.66-0.97) compared to dMT. The two groups did not differ in functional improvement (adjusted cOR = 1.24, 95% CI = 0.89-1.74) or symptomatic intracranial hemorrhage (adjusted OR = 0.87, 95% CI = 0.61-1.25).

INTERPRETATION

BT appears to be associated with improved functional independence without evidence for safety concerns, compared to dMT, for AIS patients with LVO. ANN NEUROL 2019;86:395-406.