Evaluation of acute mechanical revascularization in large stroke (ASPECTS ⩽5) and large vessel occlusion within 7 h of last-seen-well: The LASTE multicenter, randomized, clinical trial protocol

Treatment of Acute Ischemic Stroke: The Last 30 Years of Trials and Tribulations

The landscape of acute ischemic stroke management has undergone a substantial transformation over the past 3 decades, mirroring our enhanced comprehension of the pathology and progress in diagnostic techniques, therapeutic interventions, and preventive measures. The 1990s marked a pivotal moment in stroke care with the integration of intravenous thrombolytics. However, the most significant paradigm shift in recent years has undoubtedly been the advent of endovascular thrombectomy. This article endeavors to deliver an exhaustive analysis of this revolutionary progression.

Endovascular Therapy and Outcomes Among Patients With Very Large Ischemic Core Stroke

Importance

The association of endovascular therapy (EVT) with outcomes is unclear for patients with very low Alberta Stroke Program Early Computed Tomography Score (ASPECTS) within 24 hours of stroke onset.

Objective

To explore the association of EVT with functional and safety outcomes among patients with ASPECTS of 0 to 2 scored with noncontrast computed tomography.

Design, Setting, and Participants

This cohort study used data from an ongoing, prospective, observational, nationwide registry including all patients treated at 38 stroke centers in China with an occlusion in the internal carotid artery or M1 or M2 segment of the middle cerebral artery within 24 hours of witnessed symptom onset. Patients with ASPECTS of 0 to 2 between November 1, 2021, and February 8, 2023, were included in analysis. Data were analyzed October to November 2023.

Exposures

EVT vs standard medical treatment (SMT).

Main Outcomes and Measures

The primary outcome was favorable functional outcome, defined as modified Rankin Scale score (mRS) of 0 to 3, at 90 days. Safety outcomes included symptomatic intracerebral hemorrhage (sICH) within 48 hours and mortality at 90 days.

Results

A total of 245 patients (median [IQR] age, 71 [63-78] years; 118 [48%] women) with ASPECTS of 0 to 2 were included, of whom 111 patients (45.1%) received SMT and 135 patients (54.9%) received EVT. The EVT group had significantly greater odds of favorable functional outcome at 90 days than the SMT group (30 patients [22.2%] vs 11 patients [9.9%]; P = .01; adjusted odds ratio [aOR], 3.07 [95% CI, 1.29-7.31]; P = .01). Patients in the EVT group, compared with the SMT group, had significantly greater odds of any ICH (56 patients [41.5%] vs 16 patients [11.4%]; P < .001; aOR, 4.27 [95% CI, 2.19-8.35]; P < .001) and sICH (24 patients [17.8%] vs 1 patient [0.9%]; P < .001; aOR, 23.07 [95% CI, 2.99-177.79]; P = .003) within 48 hours. There were no differences between groups for 90-day mortality (80 patients [59.3%] vs 59 patients [53.2%]; P = .34; aOR, 1.38 [95% CI, 0.77-2.47]; P = .28). The results remained robust in the propensity score-matched analysis.

Conclusions and Relevance

In this cohort study of patients with very low ASPECTS based on NCCT within 24 hours of stroke onset, those treated with EVT had higher odds of a favorable functional outcome compared with those who received SMT. Randomized clinical trials are needed to assess these findings.

Endovascular thrombectomy for large ischemic strokes: An updated living systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Recent studies indicate endovascular thrombectomy (EVT) as a safe, effective treatment for acute ischemic stroke (AIS) with large ischemic regions. Our study updates an ongoing living systematic review and meta-analysis of randomized controlled trials (RCTs) comparing outcomes of EVT to medical management only.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library for RCTs comparing EVT to medical management in AIS patients with large ischemic areas. Using fixed-effect models, we conducted a meta-analysis to compare functional independence, mortality, and symptomatic intracranial hemorrhage (sICH) between EVT and standard medical management. We evaluated bias risk with the Cochrane tool and graded the certainty of evidence using the GRADE approach.

RESULTS

Of 1363 new citations, we included six RCTs with a total of 1876 patients. We found low-certainty evidence of improved functional independence (risk difference [RD] 29.9%, 95% CI 17.2% to 46.9%), increase in sICH (RD 2.6%, 95% CI 0.3% to 6.4%), and a non-significant decrease in mortality (RD -1.8%, 95% CI -3.9% to 0.6%) for AIS patients with large infarcts who underwent EVT compared to medical management only.

CONCLUSION

Our revised meta-analysis suggests low-certainty evidence that there is improved functional independence, a non-significant decrease in mortality, and an increase in sICH among AIS patients with large infarcts who undergo EVT compared to those receiving medical management alone.

SYSTEMATIC REVIEW PROTOCOL REGISTRATION

PROSPERO (CRD42023398742).

Association of Carotid Artery Disease with Collateralization and Infarct Growth in Patients with Acute Middle Cerebral Artery Occlusion

BACKGROUND AND PURPOSE

Collaterals are important in large vessel occlusions (LVO), but the role of carotid artery disease (CAD) in this context remains unclear. This study aimed to investigate the impact of CAD on intracranial collateralization and infarct growth after thrombectomy in LVO.

MATERIALS AND METHODS

All patients who underwent thrombectomy due to M1 segment occlusion from 01/2015 to 12/2021 were retrospectively included. Internal carotid artery stenosis according to NASCET was assessed on the affected and nonaffected sides. Collaterals were assessed according to the Tan score. Infarct growth was quantified by comparing ASPECTS on follow-up imaging with baseline ASPECTS.

RESULTS

In total, 709 patients were included, 118 (16.6%) of whom presented with CAD (defined as severe stenosis ≥70% or occlusion ipsilaterally), with 42 cases (5.9%) being contralateral. Good collateralization (Tan 3) was present in 56.5% of the patients with ipsilateral CAD and 69.1% of the patients with contralateral CAD. The ipsilateral stenosis grade was an independent predictor of good collateral supply (adjusted OR: 1.01; NASCET point, 95% CI: 1.00-1.01; P = .009), whereas the contralateral stenosis grade was not (P = .34). Patients with ipsilateral stenosis of ≥70% showed less infarct growth (median ASPECTS decay: 1; IQR: 0-2) compared with patients with 0%-69% stenosis (median: 2; IQR: 1-3) (P = .005). However, baseline ASPECTS was significantly lower in patients with stenosis of 70%-100% (P < .001). The results of a multivariate analysis revealed that increasing ipsilateral stenosis grade (adjusted OR: 1.0; 95% CI: 0.99-1.00; P = .004) and good collateralization (adjusted OR: 0.5; 95% CI: 0.4-0.62; P < .001) were associated with less infarct growth.

CONCLUSIONS

CAD of the ipsilateral ICA is an independent predictor of good collateral supply. Patients with CAD tend to have larger baseline infarct size but less infarct growth.

The Association Between National Institutes of Health Stroke Scale Score and Clinical Outcome in Patients with Large Core Infarctions Undergoing Endovascular Treatment

INTRODUCTION

This study aimed to analyze the association between baseline National Institutes of Health Stroke Scale (NIHSS) scores and clinical outcomes in patients with large core infarctions undergoing endovascular treatment (EVT), a relationship that remains unclear.

METHODS

Data were obtained from the MAGIC study, a prospective multicenter cohort study focusing on patients with acute large core ischemic stroke. This analysis evaluated the impact of NIHSS scores on EVT outcomes in patients with large core infarctions. Primary outcome metrics included favorable outcomes (modified Rankin Scale [mRS] of 0-3 at 90 days), while secondary outcomes encompassed shifts in mRS scores, functional independence (mRS score of 0-2), mRS score of 0-4, and successful recanalization rates. Adverse events considered were symptomatic intracranial hemorrhage (sICH) and mortality.

RESULTS

A total of 490 patients were enrolled in this study. Higher baseline NIHSS scores were inversely correlated with favorable outcomes (adjusted odds ratio [OR] in model 3, 0.848 [0.797-0.903], P < 0.001), particularly in patients with NIHSS scores above 20 (adjusted OR in model 3, 0.518 [0.306-0.878] vs. 0.290 [0.161-0.523]). Regarding adverse events, higher baseline NIHSS scores significantly correlated with increased 90-day mortality rates (adjusted OR in model 3, 1.129 [1.072-1.189], P < 0.001). This correlation became insignificant when baseline NIHSS scores exceeded 22. Additionally, baseline NIHSS scores partially mediated the association between age (indirect effect = - 0.0005, 19.39% mediated) and sex (indirect effect = 0.0457, 25.08% mediated) with the primary outcome.

CONCLUSIONS

The findings indicate that higher baseline NIHSS scores correlate with poorer outcomes and increased mortality, particularly when scores exceed 20. Moreover, age and sex indirectly influence favorable outcomes through their association with baseline NIHSS scores.

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial

BACKGROUND

Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients.

METHODS

SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed.

FINDINGS

The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]).

INTERPRETATION

In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up.

FUNDING

Stryker Neurovascular.

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

INTRODUCTION

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial

Importance

Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT).

Objective

To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes.

Design, Setting, and Participants

This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024.

Interventions

EVT vs MM.

Main Outcomes and Measures

Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication.

Results

A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80).

Conclusions and Relevance

Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Unsuccessful Recanalization versus Medical Management of Patients with Large Ischemic Core : Analysis of the ANGEL-ASPECT Randomized Trial

PURPOSE

The outcomes of patients with large ischemic core who fail to recanalize with endovascular therapy (EVT) compared to medical management (MM) are uncertain. The objective was to evaluate the clinical and safety outcomes of patients who underwent EVT in patients with large ischemic core and unsuccessful recanalization.

METHODS

This was a post hoc analysis of the ANGEL-ASPECT randomized trial. Unsuccessful recanalization was defined as patients who underwent EVT with eTICI 0-2a. The primary endpoint was 90-day very poor outcome (mRS 5-6). Multivariable logistic regression was conducted controlling for ASPECTS, occlusion location, intravenous thrombolysis, and time to treatment.

RESULTS

Of 455 patients 225 were treated with MM. Of 230 treated with EVT, 43 (19%) patients had unsuccessful recanalization. There was no difference in 90-day very poor outcomes (39.5% vs. 40%, aOR 0.93, 95% confidence interval, CI 0.47-1.85, p = 0.95), sICH (7.0% vs. 2.7%, aOR 2.81, 95% CI 0.6-13.29, p = 0.19), or mortality (30% vs. 20%, aOR 1.65, 95% CI 0.89-3.06, p = 0.11) between the unsuccessful EVT and MM groups, respectively. There were higher rates of ICH (55.8% vs. 17.3%, p < 0.001), infarct core volume growth (142.7 ml vs. 90.5 ml, β = 47.77, 95% CI 20.97-74.57 ml, p < 0.001), and decompressive craniectomy (18.6% vs. 3.6%, p < 0.001) in the unsuccessful EVT versus MM groups.

CONCLUSION

In a randomized trial of patients with large ischemic core undergoing EVT with unsuccessful recanalization, there was no difference in very poor outcomes, sICH or death versus medically managed patients. In the unsuccessful EVT group, there were higher rates of any ICH, volume of infarct core growth, and decompressive craniectomy.

Comparative Outcomes of Mechanical Thrombectomy in Acute Ischemic Stroke Patients with ASPECTS 2-3 vs. 4-5

BACKGROUND

The influence of Alberta Stroke Program Early CT Score (ASPECTS) on outcomes following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) patients with low ASPECTS remains unknown. In this study, we compared the outcomes of AIS patients treated with MT for large vessel occlusion (LVO) categorized by ASPECTS value.

METHODS

We conducted a retrospective analysis involving 305 patients with AIS caused by LVO, defined as the occlusion of the internal carotid artery and/or the M1 segments of the middle cerebral artery, stratified into two groups: ASPECTS 2-3 and 4-5. The primary outcome was favorable outcome defined as a 90-day modified Rankin Scale (mRS) score of 0-3. Secondary outcomes were 90-day mRS 0-2, 90-day mortality, any intracerebral hemorrhage (ICH), and symptomatic ICH (sICH). We performed multivariable logistic regression analysis to evaluate the impact of ASPECTS 2-3 vs. 4-5 on outcomes.

RESULTS

Fifty-nine patients (19.3%) had ASPECTS 2-3 and 246 (80.7%) had ASPECTS 4-5. Favorable outcomes showed no significant difference between the two groups (adjusted odds ratio [aOR]= 1.13, 95% confidence interval [CI]: 0.52-2.41, p=0.80). There were also no significant differences in 90-day mRS 0-2 (aOR= 1.65, 95% CI: 0.66-3.99, p=0.30), 90-day mortality (aOR= 1.14, 95% CI: 0.58-2.20, p=0.70), any ICH (aOR= 0.54, 95% CI: 0.28-1.00, p=0.06), and sICH (aOR= 0.70, 95% CI: 0.27-1.63, p = 0.40) between the groups.

CONCLUSIONS

AIS patients with LVO undergoing MT with ASPECTS 2-3 had similar outcomes compared to ASPECTS 4-5.

Predictors of parenchymal hematoma and clinical outcome after mechanical thrombectomy in patients with large ischemic core due to large vessel occlusion: a retrospective multicenter study

BACKGROUND

The aim of our study was to find predictors of parenchymal hematoma (PH) and clinical outcome after mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) and baseline large infarct.

METHODS

The databases of 16 stroke centers were retrospectively screened for patients with anterior circulation LVO and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤5 that received MT. Procedural parameters, including the number of passes during first and second technique of MT, were recorded. Outcome measures were occurrence of PH type 2 and any type of PH after MT, and the 90-day modified Rankin Scale (mRS) score of 0-3 and 0-2.

RESULTS

In total, 408 patients were available for analysis. A higher number of passes in the second technique was predictive of PH type 2 (odds ratio (OR) - 3.204, 95% confidence interval (CI) 1.140 to 9.005), whereas procedure conducted under general anesthesia was associated with lower risk (OR 0.127, 95% CI 0.002 to 0.808). The modified thrombolysis in cerebral infarction grade 2c-3 was associated with the mRS score 0-3 (OR 3.373, 95% CI 1.891 to 6.017), whereas occurrence of PH type 2 was predictive of unfavorable outcome (OR 0.221, 95% CI 0.063 to 0.773). Similar results were found for the mRS score 0-2 outcome measure.

CONCLUSION

In patients with large ischemic core, a higher number of passes during MT and procedure not conducted under general anesthesia are associated with increased rate of PH type 2, that negatively impact the clinical outcome. Our data outline a delicate balance between the need of a complete recanalization and the risk of PH following MT.

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

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