Mechanical Thrombectomy for Minor and Mild Stroke Patients Harboring Large Vessel Occlusion in the Anterior Circulation

Effectiveness and Safety of Mechanical Thrombectomy in Mild Stroke due to Large-Vessel Occlusion: Insights from the ASSIST Registry

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) is effective for acute ischemic stroke, yet its indication in mild stroke remains unclear. This study evaluates the effectiveness and safety of MT in patients with low NIHSS scores and assesses the impact of different MT strategies on procedural success and clinical outcomes.

MATERIALS AND METHODS

Data from the ASSIST Registry were analyzed. We categorized patients with large-vessel occlusion of the anterior circulation into mild (NIHSS ≤5) and moderate-severe (NIHSS >5) stroke groups. Baseline characteristics, procedural parameters, angiographic and imaging outcomes, clinical outcomes, and safety end points were compared. Within the mild stroke subgroup, outcomes were compared between different MT techniques.

RESULTS

Among 1360 patients with large-vessel occlusion, 122 had minor ischemic strokes (9%). Patients with mild stroke had high rates of excellent functional outcomes (mRS 0-1) at 90 days (77.1%) and functional independence (mRS 0-2) (85.7%). Procedural success rates were similar between NIHSS groups, while safety outcomes, except mortality, were comparable. No statistically significant differences were observed in treatment techniques within the mild stroke subgroup. Significant predictors of early neurologic deterioration (END) in patients with mild stroke were the total number of passes (OR, 1.49; 95% CI, 1.01-2.19; P = .04) and total procedural time (OR, 1.02; 95% CI, 1.01-1.04; P = .01). Patients with END were more likely to have an unfavorable functional outcome (mRS 3-6) at 90 days (89% versus 6%, P < .001).

CONCLUSIONS

MT is effective and safe in patients with mild stroke. Procedural success did not vary among MT techniques in mild stroke. The total number of passes predict END, which suggests a causal pathway that requires further exploration.

Disabling Neurologic Deficits and Antiplatelet Therapy in Acute Minor Stroke

BACKGROUND

This study aimed to assess the clinical outcome among patients with minor stroke, both with and without disabling neurologic deficits (DNDs). It sought to investigate the efficacy of antiplatelet therapy using clopidogrel-aspirin versus aspirin alone within the framework of the CHANCE (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events) trial.

METHODS AND RESULTS

We enrolled 3725 patients with minor stroke from the CHANCE trial. Patients were divided into 2 groups: those with DNDs and those without, based on the presence or absence of DND, as determined by the baseline National Institutes of Health Stroke Scale score. The interaction between the treatment effects of antiplatelet therapy in patients with or without DNDs was analyzed using the Cox proportional hazards regression model. Of all enrolled patients, 1918 (51.5%) had DNDs, and 1807 (48.5%) did not. Patients with DNDs exhibited a higher risk of stroke recurrence at 90 days compared with those without (11.9% versus 8.5%; P=0.008). Dual antiplatelet therapy with clopidogrel and aspirin was associated with a reduced risk of recurrent stroke compared with the mono antiplatelet therapy in both patients with DND and patients without DNDs (adjusted hazard ratios, 0.74 [95% CI, 0.57-0.96] and 0.64 [95% CI, 0.46-0.88], respectively). There was no significant interaction between DNDs and antiplatelet therapy in reducing stroke recurrence (interaction P=0.634).

CONCLUSIONS

DNDs appear to correlate with an elevated risk of recurrent stroke in patients with minor stroke. Dual antiplatelet therapy demonstrates superiority over aspirin alone in reducing the risk of subsequent stroke events within 90 days in patients, regardless of the presence of DNDs.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique Identifier: NCT00979589.

Thrombectomy in Stroke Patients with Large Vessel Occlusion and Mild Symptoms: Insights from a Multicenter Observational Study

To evaluate whether endovascular thrombectomy (EVT) combined with best medical management (BMM) is more effective than BMM alone in treating mild stroke patients (National Institutes of Health Stroke Scale score < 6) with large vessel occlusion (LVO). A multicentric retrospective cohort of patients with LVO and mild stroke within 24 h from symptom onset was included. Patients were divided into the primary EVT (EVTpri) group and the primary BMM (BMMpri) group according to the treatment strategy. Functional outcomes were compared after propensity score matching. Additionally, adjusted logistic regression analysis was used to assess the association between treatment strategy and functional outcomes. Finally, 419 patients were included, with 137 receiving EVTpri and 282 receiving BMMpri. After propensity score matching (EVTpri, 126 vs. BMMpri, 126), baseline characteristics were balanced between the two groups. No significant difference was observed in 3-month functional independence (modified Rankin Scale [mRS] 0-2, 78.6% vs. 76.2%. In the overall cohort, EVTpri was not associated with functional independence (adjusted odds ratio [aOR], 0.87; 95% confidence interval [CI], 0.43-1.47). However, patients in the EVTpri group were more likely to experience symptomatic intracranial hemorrhage (aOR, 1.27; 95% CI, 1.05-1.89). Subgroup analysis revealed that EVTpri was significantly associated with functional independence in vertebrobasilar occlusion subgroup (aOR, 1.78; 95% CI, 1.20-3.90). Our findings did not support the systematic use of EVT for mild stroke with LVO, except in cases of vertebrobasilar occlusion, which may represent a subgroup where EVTpri could provide significant benefits.

Determining Outcomes in Patients With Large Vessel Occlusion and Mild Stroke Who Did or Did Not Receive Thrombolytics and/or Thrombectomy

OBJECTIVES

The utility of thrombolysis and/or thrombectomy in patients with mild stroke and large vessel occlusion (LVO) remains inconclusive. This retrospective study compared short-term and long-term outcomes in patients treated with best medical therapy (BMT group) versus with intravenous thrombolytics and/or endovascular thrombectomy (intervention group).

METHODS

Patients with acute ischemic stroke (AIS), LVO, and National Institutes of Health Stroke Score (NIHSS) ≤5 were included. Data collected includes demographics; hospital length of stay (LOS); modified Rankin scale (mRS) at admission, discharge, and follow-up; hemorrhagic conversion; and disposition. Bivariate analyses were conducted to compare outcomes between groups.

RESULTS

Of the 29 patients, 15 were treated with BMT and 14 underwent intervention. Median hospital LOS was slightly longer in the intervention group (6.5 [IQR=4 to 12] vs. 5 [IQR=3 to 5] d, P=0.070). Everyone in the BMT group had a favorable outcome (mRS 0 to 2) at discharge and follow-up, unlike the intervention group's rate at discharge (100% vs. 71.4%, P=0.042), This gap was closed at follow-up between BMT group (median=33 d, IQR=28 to 48) and intervention group (median=44.5 days, IQR=30 to 48) (100% vs. 85.7%, P=0.224). Hemorrhagic conversion rates were similar between groups. More patients in the BMT group were discharged home (80% vs. 42.9%, P=0.079).

CONCLUSIONS

Patients with AIS, low NIHSS, and LVO, who received thrombolytics and/or thrombectomy had longer hospital LOS, higher mRS at discharge and follow-up, and were less likely to be discharged home, though these trends were not statistically significant. Our study is limited by a small sample size and these findings should be further explored in larger studies.

Comparing the efficacy and safety of bridging therapy vs. monotherapy in patients with minor stroke: a meta-analysis

The two main therapeutic approaches for stroke treatment are endovascular thrombectomy, which involves mechanically removing the thrombus, and bridging therapy, which uses intravenous thrombolytics (IVT) prior to endovascular thrombectomy (EVT). This study aimed to compare monotherapy (EVT or IVT alone) with bridging therapy (IVT+EVT) in terms of efficacy and safety outcomes in patients with minor ischemic stroke. After a thorough screening, eight studies were included for qualitative synthesis and meta-analysis, comprising a total of 3,117 patients across the treatment arms. The main outcomes of interest were the efficacy of treatment modality, the rate of intracerebral hemorrhage (ICH), and mortality. In terms of functional outcomes measured by the Modified Rankin Score (mRs) 0-1, no significant difference was observed when comparing IVT monotherapy with bridging therapy (IVT+EVT), with an odds ratio of 0.79 (P = 0.41). However, IVT was associated with a decreased risk of symptomatic intracranial hemorrhage (sICH) compared to bridging therapy (OR = 0.51; P = 0.02), while EVT was associated with an increased risk of sICH compared to bridging therapy (OR = 8.33; P = 0.01). Mortality rates were comparable between IVT alone compared to bridging therapy and EVT alone compared to bridging therapy (P = 0.14). Although both treatment modalities share similar efficacy, there was a trend in favoring bridging therapy for mortality rates, but it was not statistically significant. Future randomized controlled trials and updated systematic reviews are needed within five to ten years to increase sample sizes and potentially identify statistically significant differences in mortality and other outcomes.

Emergent endovascular treatment versus medical treatment for acute large vessel occlusions with nondisabling symptoms

OBJECTIVES

The aim of this study is to analyze the effectiveness and safety of medical treatment (MT) versus endovascular treatment (EVT) in acute large vessel occlusion patients with mild nondisabling stroke symptoms.

METHODS

This study is a multicenter observational study in which data from patients at three stroke centers were prospectively obtained and retrospectively analyzed. Patients were included if they arrived for treatment within 6 h of stroke onset or last known well time and had a baseline National Institutes of Health Stroke Scale (NIHSS) score of ≤5. Primary outcome was modified Rankin Scale (mRS) score 0-2 at 90 days. Secondary outcomes included symptomatic intracranial hemorrhage (sICH), discharge NIHSS score, 90-day all-cause mortality and length of stay. Clinical outcomes were compared through a multivariable logistic regression after adjusting for age, treatment type admission and discharge NIHSS score, admission Alberta Stroke Program Early CT (ASPECT) score and length of stay.

RESULTS

Of the 82 patients included in the study, 42 were in the EVT group and 40 were in the MT group. The groups were similar in age (MT:66, EVT:64 age; p = .62), gender (MT:55%, EVT:54.8%; male) admission NIHSS score (MT:2, EVT:3 points; p = .26), ASPECT score (MT:10, EVT:9; p = .15). While discharge NIHSS score was found to be statistically significant between the groups (MT:1, EVT:2; p = .04). There was no difference between the two groups in terms of 90-day mRS scores (MT:1, EVT:1, p = .86) and mortality rates (MT:4, EVT:4; p = .94). In unadjusted analysis, sICH rates were similar between the MT and EVT groups (MT 5%, EVT 7.1%, p = .52). Neurological intensive care unit length of stay (MT:5 days, EVT:2 days p < .001), inpatient clinic length of stay (MT:3, EVT:2 days p = .041), and total length of stay (MT:9 days, EVT:4 days p < .001) were significantly longer in the MT group.

CONCLUSIONS

Our multicenter study demonstrated that MT with blood pressure augmentation and anticoagulation at hyperacute stage is an alternative option for emergency large vessel occlusion patients with nondisabling mild stroke symptoms.

Minor strokes: Addressing the challenges of recanalization therapies and secondary prevention

Minor strokes, which account for about 50 % of all ischemic strokes are not necessarily benign and carry a substantial risk of long-term disability. Due to persisting uncertainties regarding optimal recanalization strategies mild strokes may represent a therapeutical challenge for clinicians. The aim of this review is to provide an overview of the current state of knowledge and questions remaining to be answered.

Is Thrombectomy Effective for Large Vessel Occlusion Stroke Patients with Mild Symptoms? Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Endovascular treatment (EVT) is an established method for managing large vessel occlusion (LVO), but its efficacy in patients with mild stroke (National Institutes of Health Stroke Scale [NIHSS] score < 6) remains debated. Given the clinical problem of early neurological deterioration in approximately 10% of mild stroke patients, understanding the role of EVT in managing these patients is crucial. Our objective was to perform a meta-analysis with trial sequential analysis (TSA) focusing on mild stroke patients with LVO to determine whether EVT offers better outcomes than best medical therapy alone.

METHODS

A comprehensive search of PubMed, Cochrane, and Embase databases up to 12 December 2023 identified 14 retrospective and prospective cohort studies, including a total of 4436 patients with NIHSS scores less than 6 and presenting with LVO. Studies were categorized into crossover and non-crossover groups to prevent overestimation of the treatment effect. In the crossover group, patients initially treated with BMT were moved to EVT upon clinical deterioration. In the non-crossover group, patients remained in their initially assigned treatment. Meta-analysis and data extraction followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The primary outcome was achieving an excellent functional outcome, defined as a modified Rankin scale (mRS) score of 0-1 at 3 months. Secondary outcomes included good (mRS 0-2) and favorable (mRS 0-3) functional outcomes. Safety outcomes were symptomatic intracerebral hemorrhage (sICH) and mortality at 3 months.

RESULTS

In the crossover group, EVT did not significantly improve excellent functional outcomes, and TSA results were inconclusive. Conversely, in the non-crossover group, EVT significantly improved the excellent functional outcome rates at 3 months (65.0% vs. 53.7%; OR 1.62; 95% CI 1.13 to 2.32), supported by TSA. EVT increased the risk of sICH in both crossover and non-crossover groups, while mortality rates did not significantly differ between EVT and BMT groups.

CONCLUSIONS

Our research indicates that thrombectomy may not significantly help mild stroke patients in recovering functional status and could increase the risk of sICH. The disparity in results between crossover and non-crossover studies highlights the critical need for the prompt identification of patients at risk of early neurological deterioration to minimize negative outcomes. Additional randomized controlled trials are essential to optimize the application of EVT in this patient population.

Intravenous thrombolysis versus dual antiplatelet therapy in minor ischemic stroke within the thrombolytic window (TAMIS): a multicenter cohort study

Intravenous thrombolysis (IVT) and dual antiplatelet therapy (DAPT) have been widely used in minor ischemic stroke (MIS) treatment. However, the clinical outcomes and safety of these two treatments have not been compared within the early thrombolytic time window. Here, we conducted a multicenter, ambispective cohort study involving patients with MIS presenting within 4.5 h of symptom onset at 3 affiliated hospitals of Jinan University from 2018-2022. The patients were divided into the IVT group and DAPT group. The primary outcome was a 90-day excellent outcome (mRS ≤ 1). A total of 1,026 patients were enrolled, of whom 492 were assigned to the IVT group and 534 were assigned to the DAPT group. The IVT group had better 90-day excellent outcomes (mRS ≤ 1) than the DAPT group (OR 1.69, 95% CI 1.14-2.52, P = 0.010). Among the 623 patients with nondisabling stroke, the proportion of mRS ≤ 1 in the IVT group was higher than the DAPT group (P = 0.009). In the subtypes of MIS with large vessel occlusion/stenosis and with isolated symptoms, the 90-day outcomes of the IVT group and DAPT group were not different (P > 0.05). In conclusion, compared with DAPT, IVT was associated with better 90-day clinical outcomes in patients with MIS (in particular, for those with mRS > 1), including earlier clinical improvement.IVT also benefited the early neurological improvement of patients with severe stenosis/occlusion of intracranial large vessels, nondisabling mild stroke, nondisabling mild stroke with isolated symptoms.

Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores ≥ 6 and ≤ 6

BACKGROUND

While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce.

PURPOSE

To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions.

MATERIALS AND METHODS

Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤ 6) versus and higher stroke scale scores (> 6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed.

RESULTS

Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in ≤ 6 and 88.7% in the > 6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the ≤ 6 stroke scale group was 5.3% versus 13.3% in the > 6 stroke scale group.

CONCLUSION

Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.

Endovascular Versus Medical Therapy in Posterior Cerebral Artery Stroke: Role of Baseline NIHSS Score and Occlusion Site

BACKGROUND

Acute ischemic stroke with isolated posterior cerebral artery occlusion (iPCAO) lacks management evidence from randomized trials. We aimed to evaluate whether the association between endovascular treatment (EVT) and outcomes in iPCAO acute ischemic stroke is modified by initial stroke severity (baseline National Institutes of Health Stroke Scale [NIHSS]) and arterial occlusion site.

METHODS

Based on the multicenter, retrospective, case-control study of consecutive iPCAO acute ischemic stroke patients (PLATO study [Posterior Cerebral Artery Occlusion Stroke]), we assessed the heterogeneity of EVT outcomes compared with medical management (MM) for iPCAO, according to baseline NIHSS score (≤6 versus >6) and occlusion site (P1 versus P2), using multivariable regression modeling with interaction terms. The primary outcome was the favorable shift of 3-month modified Rankin Scale (mRS). Secondary outcomes included excellent outcome (mRS score 0-1), functional independence (mRS score 0-2), symptomatic intracranial hemorrhage, and mortality.

RESULTS

From 1344 patients assessed for eligibility, 1059 were included (median age, 74 years; 43.7% women; 41.3% had intravenous thrombolysis): 364 receiving EVT and 695 receiving MM. Baseline stroke severity did not modify the association of EVT with 3-month mRS distribution (Pinteraction=0.312) but did with functional independence (Pinteraction=0.010), with a similar trend on excellent outcome (Pinteraction=0.069). EVT was associated with more favorable outcomes than MM in patients with baseline NIHSS score >6 (mRS score 0-1, 30.6% versus 17.7%; adjusted odds ratio [aOR], 2.01 [95% CI, 1.22-3.31]; mRS score 0 to 2, 46.1% versus 31.9%; aOR, 1.64 [95% CI, 1.08-2.51]) but not in those with NIHSS score ≤6 (mRS score 0-1, 43.8% versus 46.3%; aOR, 0.90 [95% CI, 0.49-1.64]; mRS score 0-2, 65.3% versus 74.3%; aOR, 0.55 [95% CI, 0.30-1.0]). EVT was associated with more symptomatic intracranial hemorrhage regardless of baseline NIHSS score (Pinteraction=0.467), while the mortality increase was more pronounced in patients with NIHSS score ≤6 (Pinteraction=0.044; NIHSS score ≤6: aOR, 7.95 [95% CI, 3.11-20.28]; NIHSS score >6: aOR, 1.98 [95% CI, 1.08-3.65]). Arterial occlusion site did not modify the association of EVT with outcomes compared with MM.

CONCLUSIONS

Baseline clinical stroke severity, rather than the occlusion site, may be an important modifier of the association between EVT and outcomes in iPCAO. Only severely affected patients with iPCAO (NIHSS score >6) had more favorable disability outcomes with EVT than MM, despite increased mortality and symptomatic intracranial hemorrhage.

A comparison of endovascular therapy and medical management in patients with large vessel occlusion mild stroke treated between 2015 and 2023: a systematic review and meta-analysis

OBJECTIVE

Endovascular therapy (EVT) is recommended for patients with acute large-vessel occlusion (LVO) However, its efficacy and safety compared to medical management (MM) in patients with a National Institutes of Health Stroke Scale (NIHSS) score of ≤6 remains unclear. This meta-analysis compared EVT with medical MM in patients with large vessel occlusion mild stroke treated between 2015 and 2023, following the publication of the first randomized controlled trial.

MATERIALS AND METHODS

Biomedical database searches (inception to March 21, 2023) retrieved articles reporting favorable functional outcome(modified Rankin Scale [mRS] 0-1) and functional independence (mRS 0-2), 90-day mortality and symptomatic intracranial hemorrhage (sICH). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) to maintain methodological rigor and transparency in our meta-analysis.

RESULTS

We conducted a meta-analysis of 22 studies (4,985 patients) to reveal no significant differences in favorable functional outcomes and independence across all groups. However, in patients treated between 2015 and 2023, EVT exhibited a higher risk of 90-day mortality (Odds Ratio [OR] = 1.84, 95% Confidence Interval [CI] [1.10, 3.07], p = 0.02) and sICH (OR = 3.36, 95% CI [1.96, 6.66], p < 0.01). EVT correlated with elevated sICH in the anterior circulation (OR=2.94, 95%CI [1.82, 4.74], p<0.01) regardless of the proximal (OR=2.20, 95%CI [1.04, 4.69], p=0.04) or distal (OR=3.44, 95%CI [1.43, 8.32], p<0.01) location of the occlusion. EVT correlated with elevated sICH rates in patients treated within 6 hours of symptom onset or those with NHISS≤5.

CONCLUSION

In patients treated between 2015 and 2023, EVT and MM did not differ in efficacy in acute LVO mild stroke; MM associated with better safety outcomes. Rigorous randomized controlled trials are warranted.

Mechanical Thrombectomy for Pediatric Arterial Ischemic Stroke from Acute M2 Occlusion

Pediatric large-vessel occlusion has a poor natural history. Recent retrospective studies have demonstrated the potential benefits, feasibility, and safety profile of mechanical thrombectomy in children. However, the role of thrombectomy in pediatric M2 occlusions remains uncertain. In this clinical report, we present a multicenter series of 6 pediatric patients with acute M2 occlusion (female = 1, male = 5; age range, 0.9-16.0 years, mean = 9.2). All 6 patients having undergone thrombectomy had excellent clinical outcomes (pediatric mRS = 0-1) at 3 months and final available follow-up (median, 12 months; range, 3-72 months). Factors relevant to treatment decision-making in pediatric M2 occlusions are discussed, including the important role of multidisciplinary team discussions during acute management.

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.

Common design and data elements reported in active mechanical thrombectomy trials focusing on distal medium vessel occlusions and minor strokes: a systematic review

BACKGROUND

Distal medium vessel occlusions (DMVOs) and minor strokes represent emerging frontiers in mechanical thrombectomy (MT). Although several randomized clinical trials (RCTs) are underway, the design characteristics of these trials and the specific questions they aim to address have not been extensively explored. This current study sought to investigate the design and data elements reported in active prospective DMVO and minor stroke studies.

METHODS

The ClinicalTrials.gov database was searched for ongoing prospective studies assessing the role of MT in patients with DMVOs or minor strokes. The Nested Knowledge AutoLit platform was utilized to categorize reported outcomes and inclusion/exclusion criteria. Frequencies of reported data elements were extracted from study protocols.

RESULTS

A total of 10 (8 DMVO and 2 minor stroke) studies enrolling 3520 patients were included. All DMVO studies employ different criteria regarding target occlusion locations. Five DMVO studies use stent retrievers as the first-line thrombectomy technique (62.5%, 5/8), while three studies allow any MT techniques, generally at the operator's discretion. Four DMVO studies permit intravenous thrombolysis (IVT) utilization in both intervention and control arms (50%, 4/8). The DISTALS trial excludes patients receiving IVT, while the DUSK trial and Tigertriever registry only enroll patients who are ineligible for IVT or for whom IVT failed to achieve reperfusion. DMVO studies exhibit notable heterogeneity in symptom onset duration thresholds for inclusion (<6 hours: 2 studies; <12 hours: 2 studies; <24 hours: 3 studies). Minor stroke trials employ similar inclusion criteria and outcome measures except for symptom duration thresholds for inclusion (8 hours for ENDOLOW and 23 hours for MOSTE).

CONCLUSIONS

There is considerable heterogeneity among active DMVO trials regarding potential target DMVO locations and time thresholds for inclusion based on the last known well time. Furthermore, our review indicates that the utility of aspiration thrombectomy in DMVOs and the advantages of MT without IVT over IVT alone will remain largely unexplored even after completion of active DMVO trials.

Evaluation of acute mechanical revascularization in minor stroke (NIHSS score ⩽ 5) and large vessel occlusion: The MOSTE multicenter, randomized, clinical trial protocol

RATIONALE

Mechanical thrombectomy (MT) has become the standard of care for patients with acute ischemic stroke secondary to large vessel occlusion (LVO) of the anterior circulation. Conversely, its benefit in patients with National Institutes of Health Stroke Scale (NIHSS) score ⩽ 5 is unproven.

AIM

To demonstrate the superiority of immediate MT plus best medical treatment (BMT) compared to BMT (with secondary MT in case of deterioration) for increasing the rate of modified Rankin Scale (mRS) score ⩽ 1 at 90 days after minor stroke (NIHSS score ⩽ 5) and anterior circulation LVO.

SAMPLE SIZE ESTIMATES

To detect an absolute increase of 10% (80% power) in the 90-day mRS score = 0-1 rate in the MT + BMT group, by assuming an mRS score = 0-1 rate of 60% in the BMT group and by considering two interim efficacy/futility analyses (after study completion by 274 and 548 patients), 824 patients must be included by 36 centers in France, Spain, and the USA.

METHODS AND DESIGN

MOSTE is an international, multicenter, prospectively randomized into two parallel (1:1) arms, open-label, with blinded endpoint trial. Eligibility criteria are diagnosis of acute ischemic stroke within 23 h of last-seen-well, NIHSS score ⩽ 5, and LVO in the anterior circulation (intracranial internal carotid artery, M1 or M1-M2 segment of the middle cerebral artery).

STUDY OUTCOMES

The primary endpoint is the rate of excellent outcome at day 90 (mRS score = 0-1). Secondary endpoints include the rates of 90-day mRS score = 0-2 and score = 0, NIHSS score change, secondary MT, revascularization and infarct volume growth at 24 h, and quality of life and cognitive function at day 90. Safety outcomes (90-day all-cause mortality, procedural complications, symptomatic intracerebral hemorrhage, and rapid NIHSS score worsening) are recorded.

DISCUSSION

The MOSTE trial will determine MT efficacy and safety in patients with minor stroke and LVO in the anterior circulation.

TRIAL REGISTRATION

MOSTE Trial. NCT03796468.

Mechanical thrombectomy for AIS from large vessel occlusion - current trends and future perspectives

Stroke is found to be one of the global top causes of mortality and the major factor in years of life with a handicap (DALYs). Ischemic strokes contributed to nearly 70% of all strokes worldwide. For endovascular thrombectomy in acute ischemic stroke with large vessel obstruction (AIS-LVO), using stent retrievers and/or reperfusion catheters has become the gold standard of therapy. The methodology involved keyword-based search in databases like PubMed, Embase, and Google Scholar for recent publications on mechanical thrombectomy (MT), AIS, large vessel occlusion (Large Vessel Occlusion (LVO)), screening relevant articles, retrieving full texts, and synthesizing key findings on procedural advancements, patient selection, COVID-19 (coronavirus disease 2019) impact, delay effects, effectiveness, clinical outcomes, and future perspectives. Only people with substantial cerebral artery obstruction may do well from MT. This includes the distal carotid artery and the proximal middle cerebral artery (segment M1). The size of a blocked vessel and NIHSS (National Institute of Health Stroke Scale) score are directly connected. Both the 2018 and 2019 versions of the AHA/ASA (American Heart Association/American Stroke Association) Guidelines for the Early Management of Patients with Acute Ischemic Stroke contained the recommendations that cases with AIS-LVO get endovascular therapy when administered during the time frame of 0-6 h after onset (Grade IA evidence). It is questionable whether this group of patients can be managed without the need for intravenous tissue plasminogen activator at the onset. When functional independence [modified Rankin Scale (mRS) score 2] was present at long-term follow-up, the endovascular intervention was favored. Tenecteplase, which differs from alteplase in terms of genetic variation, has a greater half-life and a higher level of fibrin selectivity, enabling bolus infusion. Studies have also demonstrated its efficacy and safety, as well as its long-term cost-effectiveness.

Endovascular Reperfusion Therapy in Minor Stroke with Neurologic Deterioration beyond 24 Hours from Onset

PURPOSE

Patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) and large vessel occlusion (LVO) often experience neurological deterioration >24 hours after onset. However, the efficacy of endovascular reperfusion therapy in these patients remains unclear. The aim of this study was to determine the efficacy and safety of reperfusion therapy in patients with minor stroke and neurological deterioration >24 hours after onset.

MATERIALS AND METHODS

Data were retrospectively reviewed from patients between January 2019 and April 2022 who met the following criteria: (1) minor stroke and small definitive ischemic lesions at initial visit, (2) onset to neurological deterioration >24 hours, (3) cortical signs, Alberta Stroke Program Early computed tomography (CT) Score >6 points, and large artery occlusion confirmed by CT angiography at neurological deterioration. Efficacy and safety outcomes were based on final thrombolysis in cerebral infarction (TICI), incidence of symptomatic intracranial hemorrhage (ICH), and mortality. Outcomes were assessed using the modified Rankin Scale (mRS) at 3 months. Good outcome was defined as a mRS of 0, 1, or 2.

RESULTS

Data from 26 patients (38.4% female, mean age 75.8 years) were analyzed; 18 (69.2%) had a good outcome. A final TICI of 2b or 3 was observed in 24 (92.3%) patients. No other adverse events, including dissection, vasospasm or distal embolization, were observed during the procedures. Hemorrhagic events occurred in 8 patients after the procedure; however, there were no symptomatic ICHs. Good prognostic factors were younger age (P=0.062) and carotid stenting (P=0.025).

CONCLUSION

Endovascular reperfusion therapy performed in selected patients with minor stroke, LVO, and neurological deterioration >24 hours after stroke onset demonstrated favorable outcomes and safety.

Advances in mechanical thrombectomy for acute ischaemic stroke

Mechanical thrombectomy is a ground breaking treatment for acute ischaemic stroke caused by occlusion of a large vessel. Its efficacy over intravenous thrombolysis has been proven in multiple trials with a lower number needed to treat than percutaneous coronary intervention for acute myocardial infarction. However, access to this key treatment modality remains limited with a considerable postcode lottery across the UK and many parts of the world. The evidence base for mechanical thrombectomy dates back to 2015. Since then, there have been important advances in establishing and widening the criteria for treatment. This narrative review aims to summarise the current evidence base and latest advances for physicians and academics with an interest in recanalisation treatments for acute ischaemic stroke.

Association of Perfusion Lesion Variables With Functional Outcome in Patients With Mild Stroke and Large Vessel Occlusion Managed Medically

BACKGROUND AND OBJECTIVES

The best management of patients with mild stroke and large vessel occlusion (LVO) remains unclear. This study aimed to identify perfusion imaging predictors of poor functional outcome in such patients.

METHODS

This cohort study retrospectively selected patients enrolled in the International Stroke Perfusion Imaging Registry between August 2011 and April 2022. The registry enrolled patients with acute ischemic stroke and with baseline CT perfusion scanned within 24 hours of stroke onset. This study identified patients with mild symptoms, defined by an NIH Stroke Scale score of ≤5. Patients with LVO of anterior circulation were selected. This study further selected patients who received medical management and excluded patients who received endovascular treatment. The primary outcome was poor functional outcome defined as a modified Rankin Scale of 3-6 at 3 months. Perfusion lesion was defined by delay time > 3 seconds on CTP. Regression analyses were used to identify clinical and imaging variables that predicted poor functional outcome.

RESULTS

A total of 139 patients with mild stroke were included, of whom 27 (19%) had poor functional outcome. Patients with poor outcome, compared with those with good outcome, had much larger perfusion lesion volume (median 80 mL vs 41 mL, p < 0.001). Perfusion lesion was a significant predictor of poor outcome in either univariable regression (crude OR = 1.02, 95% CI = [1.01-1.03]) or multivariable regression model (adjusted OR = 1.01, 95% CI = [1.01-1.02]), adjusting for occlusion site, good collaterals, baseline stroke severity, age, IV thrombolysis (IVT), and onset to scan time. A perfusion lesion of 65 mL was the optimal cutpoint to identify poor functional outcome (sensitivity = 59%, specificity = 77%). Patients with perfusion lesion ≥65 mL, compared with patients with perfusion lesion <65 mL, showed a much higher rate of poor functional outcome (38% vs 11%, p < 0.001). Of the 139 patients in this study, 95 received IVT. Patients treated with or without IVT did not influence their outcomes (crude OR = 0.74, 95% CI = [0.31-1.78]).

DISCUSSION

A perfusion lesion of ≥65 mL predicted poor functional outcome in mild stroke patients with LVO.

Assessing the Efficacy of Mechanical Thrombectomy in Patients with an NIHSS < 6 Presenting with Proximal Middle Cerebral Artery Vessel Occlusion as Compared to Best Medical Management

BACKGROUND AND PURPOSE

Minor acute ischemic stroke (AIS) patients-defined by an NIHSS score < 6-presenting with proximal middle cerebral artery large vessel occlusions (MCA-LVO) is a subgroup for which treatment is still debated. Although these patients present with minor symptoms initially, studies have shown that several patients afflicted with MCA-LVO in this subgroup experience cognitive and functional decline. Although mechanical thrombectomy (MT) is the standard of care for patients with an NIHSS score of 6 or higher, treatment in the minor stroke subgroup is still being explored. The purpose of this preliminary study is to report our center's experience in evaluating the potential benefit of mechanical thrombectomy (MT) in minor stroke patients when compared to medical management (MM).

METHODS

We performed a retrospective study with two comprehensive stroke centers within our hospital enterprise of consecutive patients presenting with minor AIS secondary to MCA-LVO (defined as M1 or proximal M2 segments of MCA). We subsequently evaluated patients who received MT versus those who received MM.

RESULTS

Between January 2017 and July 2021, we identified 46 AIS patients (11 treated with MT and 35 treated with MM) who presented with an NIHSS score < 6 secondary to MCA-LVO (47.8% 22/46 female, mean age 62.3 years, range 49-75 years). MT was associated with a significantly lower mRS at 90 days (median: 1.0 [IQR 0.0-2.0] versus 3.0 [IQR 1.0-4.0], p = <0.001), a favorable NIHSS shift (-4.0 [IQR -10.0--2.0] versus 0.0 [IQR -2.0-1.0], p = 0.002), favorable NIHSS shift dichotomization (5/11, 45.5% versus 3/35, 8.6%, p = 0.003) and favorable mRS dichotomization (7/11, 63.6% versus 14/35, 40.0%, p = 0.024).

CONCLUSIONS

In our center's preliminary experience, for AIS patients presenting with an NIHSS score < 6 secondary to MCA-LVO, MT may be associated with improved clinical outcomes when compared to MM only.

Sex differences in the utilization and outcomes of endovascular treatment after acute ischemic stroke: A systematic review and meta-analysis

Background

Studies of sex differences in the use and outcomes of endovascular treatment (EVT) for acute ischemic stroke report inconsistent results.

Methods

We systematically searched PubMed and Embase databases for studies examining sex-specific utilization of EVT for acute ischemic stroke published before 31 December 2021. Estimates were compared by study type: randomized clinical trials (RCTs) and non-RCTs (hospital-based, registry-based or administrative data). Random effects odds ratios (ORs) were generated to quantify sex differences in EVT use. To estimate sex differences in functional outcome on the modified Rankin scale after EVT, the female:male ratio of ORs and 95% confidence intervals (CIs) were obtained from ordinal or binary analysis.

Results

6,396 studies were identified through database searching, of which 594 qualified for a full review. A total of 51 studies (36 non-RCT and 15 RCTs) reporting on sex-specific utilization of EVT were included, and of those 10 estimated the sex differences of EVT on functional outcomes. EVT use was similar in women and men both in non-RCTs (OR: 1.03, 95% CI: 0.96-1.11) and RCTs (1.02, 95% CI: 0.89-1.16), with consistent results across years of publication and regions of study, except that in Europe EVT treatment was higher in women than men (1.15, 95% CI: 1.13-1.16). No sex differences were found in the functional outcome by either ordinal and binary analyses (ORs 0.95, 95% CI: 0.68-1.32] and 0.90, 95% CI: 0.65-1.25, respectively).

Conclusions

No sex differences in EVT utilization or on functional outcomes were evident after acute ischemic stroke from large-vessel occlusion. Further research may be required to examine sex differences in long-term outcomes, social domains, and quality of life.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=226100, identifier: CRD42021226100.

Cost-effectiveness of thrombectomy in patients with minor stroke and large vessel occlusion: effect of thrombus location on cost-effectiveness and outcomes

BACKGROUND

To evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site.

METHODS

A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed.

RESULTS

Base-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0-2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%-3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference -16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%.

CONCLUSIONS

EVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies.

Mechanical Thrombectomy in the Late Presentation of Anterior Circulation Large Vessel Occlusion Stroke: A Guideline From the Society of Vascular and Interventional Neurology Guidelines and Practice Standards Committee

Background and Purpose

Recent clinical trials investigating endovascular therapy (EVT) in the extended time window have opened new treatment paradigms for late-presenting patients with large vessel occlusion (LVO) stroke. The aim of this guideline is to provide up to date recommendations for the diagnosis, selection, and medical or endovascular treatment of patients with LVO presenting in the extended time window.

Methods

The Society of Vascular & Interventional Neurology (SVIN) Guidelines and Practice Clinical Standards (GAPS) committee assembled a writing group and recruited interdisciplinary experts to review and evaluate the current literature. Recommendations were assigned by the writing group using the SVIN-GAPS Class of Recommendation/Level of Evidence algorithm and SVIN GAPS guideline format. The final guideline was approved by all members of the writing group, the GAPS committee, and the SVIN board of directors.

Results

Literature review yielded three high quality randomized trials and several observational studies that have been extracted to derive the enclosed summary recommendations. In patients with LVO presenting in the 6-to-24-hour window, and with clinical imaging mismatch as defined by the DAWN and DEFUSE 3 studies, EVT is recommended. Non contrast CT can be used to evaluate infarct size as sole imaging modality for patient selection, particularly when access to CT perfusion or MRI is limited, or if their performance would incur substantial delay to treatment. In addition, several clinical questions were reviewed based on the available evidence and consensus grading.

Conclusion

These guidelines provide practical recommendations based on recent evidence on the diagnosis, selection, and treatment of patients with LVO stroke presenting in the extended time window.

Endovascular Treatment for Minor Acute Ischemic Strokes With Large Vessel Occlusion

Background It remains uncertain whether patients with minor acute ischemic stroke with large vessel occlusion benefit from endovascular treatment (EVT). We aim to evaluate the outcomes of EVT in minor acute ischemic stroke with anterior circulation large vessel occlusion. Methods and Results Based on a nationwide prospective stroke registry, patients with minor acute ischemic stroke with anterior circulation large vessel occlusion within 24 hours of onset were divided into groups receiving standard medical treatment plus EVT or standard medical treatment alone. Primary outcome was excellent functional outcome defined as modified Rankin Scale score 0 to 1 at 90 days. In addition, a multivariable logistic regression model was used to analyze the effect of EVT guided by perfusion imaging. A total of 572 patients with median age 68 years (interquartile range=60-77) and median National Institutes of Health Stroke score 3 (interquartile range =2-4) were identified and 123 patients were treated with standard medical treatment plus EVT. EVT was not associated with excellent functional outcome (unadjusted odds ratio [OR], 0.771 [95% CI, 0.516-1.151]; adjusted OR, 0.793 [95% CI, 0.515-1.219]; P=0.290). However, therapy selection guided by perfusion imaging was a modifier of EVT effect on outcomes, as EVT was significantly associated with excellent functional outcome (60.0% versus 50.8%, unadjusted OR, 1.451 [95% CI, 0.643-3.272]; adjusted OR, 2.849 [95% CI, 1.006-8.067]; P=0.049) but not with symptomatic intracerebral hemorrhage in the imaging-guided group. Conclusions Although functional outcomes in minor acute ischemic stroke caused by anterior circulation large vessel occlusion were not improved from the routine use of EVT, our results suggested that EVT guided by perfusion imaging could be beneficial for those patients. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04487340.

Pre-Stroke Statin Use Is Associated with Mild Neurological Deficits at the Onset of Acute Ischemic Stroke

Pre-stroke statin use reduces infarct size. Therefore, this retrospective study aimed to investigate whether pre-stroke statin use is associated with mild neurological deficits (mND) at the onset of acute ischemic stroke (AIS). We included patients with AIS admitted to our institution within 24 h of stroke onset between 2011 and 2019. We collected data on age, sex, pre-stroke use of statins, the National Institutes of Health Stroke Scale (NIHSS) score, the serum biomarker levels, and stroke subtypes at admission. In addition, we defined mND as an NIHSS score ≤3 points. We conducted a logistic regression analysis using variables for pre-stroke statin initiation, calculated the propensity scores for pre-stroke statin use, and implemented propensity score matching (PSM). Finally, we used the McNemar test to evaluate whether pre-stroke statin administration significantly affected mND. Of 4370 patients, 2615 met our inclusion criteria. Among the 594 patients with pre-stroke statin use, 308 presented with mND. After PSM, 555 patients received pre-stroke statin treatment, while 286 patients with pre-stroke statin use presented with mND at admission (p = 0.0411). The binary matched pairs contingency table of mND was not symmetrical (p = 0.0385). Pre-stroke statin use is thus associated with mND at the onset of AIS.

Biomarker of early neurological deterioration in minor stroke and proximal large vessel occlusion: A pilot study

BACKGROUND

Plasma neurofilament light chain (pNFL) represents one of the scaffolding proteins of central nervous system axonal injury. The aim of this study was to evaluate pNFL as a predictive biomarker for early neurological deterioration (END) in medically managed patients with large vessel occlusion (LVO) and mild presentation (NIHSS < 6).

METHODS

This retrospective study was developed from a prospectively collected stroke database, which was conducted at a large academic comprehensive stroke center in western China. Patients who first presented with acute ischemic stroke (AIS) within 24 h of symptom onset were continuously included. Stroke severity was analyzed at admission using the NIHSS score. The pNFL drawn on admission was analyzed with a novel ultrasensitive single-molecule array.

RESULTS

Thirty-nine consecutive patients were included in the analysis, and 19 (48.72%) patients experienced END. Patients who experienced END had significantly higher pNFL levels (mean, 65.20 vs. 48.28 pg/mL; P < 0.001) and larger infarct volume (mean, 15.46 vs. 9.56 mL; P < 0.001). pNFL was valuable for the prediction of END (OR, 1.170; 95% CI, 1.049-1.306; P = 0.005), even after adjusted for age and sex (OR, 1.178; 95% CI, 1.038-1.323; P = 0.006), blood sampling time, baseline NIHSS, TOAST classification, and infarct volume (OR, 1.168; 95% CI, 1.034-1.320; P = 0.012). The area under the ROC curve was 85.0% (95% CI, 0.731-0.970; P < 0.001). The sensitivity was 73.7%, and the specificity was 80%.

CONCLUSION

END in minor stroke with LVO was distinguishable from those without END following the determination of pNFL in the blood samples within 24 h of onset. The pNFL is a promising biomarker of END in minor stroke with LVO.

CLINICAL TRIAL REGISTRATION

ChiCTR1800020330.

Thrombectomy versus Medical Management in Mild Strokes due to Large Vessel Occlusion: Exploratory Analysis from the EXTEND-IA Trials and a Pooled International Cohort

OBJECTIVE

This study was undertaken to evaluate functional and safety outcomes for endovascular thrombectomy (EVT) versus medical management (MM) in patients with large vessel occlusion (LVO) and mild neurological deficits, stratified by perfusion imaging mismatch.

METHODS

The pooled cohort consisted of patients with National Institutes of Health Stroke Scale (NIHSS) < 6 and internal carotid artery (ICA), M1, or M2 occlusions from the Extending the Time for Thrombolysis in Emergecy Neurological Deficits - Intra-Arterial (EXTEND-IA) Trial,  Tenecteplase vs Alteplase before Endovascular Thrombectomy in Ischemic Stroke (EXTEND-IA TNK) trials Part I/II and prospective data from 15 EVT centers from October 2010 to April 2020. RAPID software estimated ischemic core and mismatch. Patients receiving primary EVT (EVT_pri ) were compared to those who received primary MM (MM_pri ), including those who deteriorated and received rescue EVT, in overall and propensity score (PS)-matched cohorts. Patients were stratified by target mismatch (mismatch ratio ≥ 1.8 and mismatch volume ≥ 15ml). Primary outcome was functional independence (90-day modified Rankin Scale = 0-2). Secondary outcomes included safety (symptomatic intracerebral hemorrhage [sICH], neurological worsening, and mortality).

RESULTS

Of 540 patients, 286 (53%) received EVT_pri and demonstrated larger critically hypoperfused tissue (Tmax > 6 seconds) volumes (median [IQR]: 64 [26-96] ml vs MM_pri : 40 [14-76] ml, p < 0.001) and higher presentation NIHSS (median [IQR]: 4 [2-5] vs MM_pri : 3 [2-4], p < 0.001). Functional independence was similar (EVT_pri : 77.4% vs MM_pri : 75.6%, adjusted odds ratio [aOR] = 1.29, 95% confidence interval [CI] = 0.82-2.03, p = 0.27). EVT had worse safety regarding sICH (EVT_pri : 16.3% vs MM_pri : 1.3%, p < 0.001) and neurological worsening (EVT_pri : 19.6% vs MM_pri : 6.7%, p < 0.001). In 414 subjects (76.7%) with target mismatch, EVT was associated with improved functional independence (EVT_pri : 77.4% vs MM_pri : 72.7%, aOR = 1.68, 95% CI = 1.01-2.81, p = 0.048), whereas there was a trend toward less favorable outcomes with primary EVT (EVT_pri : 77.4% vs MM_pri : 83.3%, aOR = 0.39, 95% CI = 0.12-1.34, p = 0.13) without target mismatch (p_interaction  = 0.06). Similar findings were observed in a propensity score-matched subpopulation.

INTERPRETATION

Overall, EVT was not associated with improved clinical outcomes in mild strokes due to LVO, and sICH was increased. However, in patients with target mismatch profile, EVT was associated with increased functional independence. Perfusion imaging may be helpful to select mild stroke patients for EVT. ANN NEUROL 2022;92:364-378.

Clinical effect of successful reperfusion in patients presenting with NIHSS < 6 and large vessel occlusion

PURPOSE

The purpose of this study was to evaluate the impact of reperfusion in patients with large vessel occlusion (LVO) of the anterior circulation and National Institutes of Health Stroke Scale (NIHSS)< 6.

METHODS

It was a retrospective cohort study. The reperfusion grade was determined using the modified thrombolysis in cerebral infarction (TICI) score. The modified Rankin Score (mRS) ≤1 were defined as excellent and (mRS) ≤2 as favorable outcome at 3-month. Meanwhile, the all-cause mortality, intracerebral hemorrhage, and complications were recorded. Multivariate logistic regression analyses were performed to evaluate outcomes.

RESULTS

Seventy-six patients (86.4%) achieved reperfusion (TICI2B/3). Excellent outcome was achieved in 62 (70.5%) and favorable outcome in 69 (78.4%). All-cause death occurred in 2 (2.3%). The rate of excellent outcome in patients with TICI0,1,2A was 41.7%, with TICI2B 69.2%, and with TICI3 78.0% (p < 0.05). In a multivariate logistic regression analysis related to excellent outcome, the OR(95% CI) was 5.68(1.35,23.95) for TICI3; the test for linear trend by entering categorical variables as continuous variables in the adjusted model (p for trend=0.02<0.05), defining TICI0,1,2A as reference. Subgroup analyses showed without intravenous thrombolysis (IVT) (OR, 14.29; 95% CI, 1.76-116.37) and with middle cerebral artery (MCA) occlusion (OR, 7.97; 95% CI,1.26-50.32), the excellent outcome further improved with TICI3. Findings were similar in favorable outcome.

CONCLUSIONS

Our results indicated that successful reperfusion was intensely connected with better functional outcomes for patients with LVO presenting with NIHSS<6 in the anterior circulation, especially MCA occlusion and pretreatment without IVT.

Minor stroke in large vessel occlusion: A matched analysis of patients from the German Stroke Registry-Endovascular Treatment (GSR-ET) and patients from the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register (SITS-ISTR)

BACKGROUND AND PURPOSE

Reperfusion treatment in patients presenting with large vessel occlusion (LVO) and minor neurological deficits is still a matter of debate. We aimed to compare minor stroke patients treated with endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT) or IVT alone.

METHODS

Patients enrolled in the German Stroke Registry-Endovascular Treatment (GSR-ET) and the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Registry (SITS-ISTR) between June 2015 and December 2019 were analyzed. Minor stroke was defined as National Institutes of Health Stroke Scale (NIHSS) score ≤5, and LVO as occlusion of the internal carotid, carotid-T, middle cerebral, basilar, vertebral or posterior cerebral arteries. GSR-ET and SITS-ISTR IVT-treated patients were matched in a 1:1 ratio using propensity-score (PS) matching. The primary outcome was good functional outcome at 3 months (modified Rankin Scale score 0-2).

RESULTS

A total of 272 GSR-ET patients treated with EVT and IVT (age 68.6 ± 14.0 years, 43.4% female, NIHSS score 4 [interquartile range 2-5]) were compared to 272 IVT-treated SITS-ISTR patients (age 69.4 ± 13.7, 43.4% female, NIHSS score 4 [2-5]). Good functional outcome was seen in 77.0% versus 82.9% (p = 0.119), mortality in 5.9% versus 7.9% (p = 0.413), and intracranial hemorrhage in 8.8% versus 12.5% (p = 0.308) of patients in the GSR-ET versus the SITS-ISTR IVT group, respectively. In a second PS-matched analysis, 624 GSR-ET patients (IVT rate 56.7%) and 624 SITS-ISTR patients (IVT rate 100%), good outcome was more often observed in the SITS-ISTR patients (68.2% vs. 80.9%; p < 0.001), and IVT independently predicted good outcome (odds ratio 2.16, 95% confidence interval 1.43-3.28).

CONCLUSIONS

Our study suggests similar effectiveness of IVT alone compared to EVT with or without IVT in minor stroke patients. There is an urgent need for randomized controlled trials on this topic.

Mechanical Thrombectomy for Mild Acute Ischemic Stroke with Large-Vessel Occlusion: A Systematic Review and Meta-Analysis

BACKGROUND

The functional prognosis of mechanical thrombectomy (MT) for mild acute ischemic stroke (AIS) with large-vessel occlusion (LVO) is controversial. To explore a more precise estimation, a meta-analysis was conducted.

METHODS

The relevant studies were identified by searching PubMed, Embase, Web of Science, and Cochrane Collaboration Database until October 2021. The pooled analysis, subgroup analysis, sensitivity analysis, and publication bias examination were all conducted. The meta-analysis was performed by using Stata 12.0.

RESULTS

Eleven studies were included with a total of 1,929 subjects, including 794 patients receiving MT and 1,135 patients receiving medical management. The pooled analysis showed that MT might be not associated with functional prognosis among mild AIS with LVO (excellent functional prognosis: risk ratio (RR) = 1.07, 95% confidence interval (CI) = 0.94-1.21, p = 0.294; favorable functional prognosis: RR = 1.01, 95% CI = 0.96-1.06, p = 0.823). The statistical stability and reliability were demonstrated by the sensitivity analysis and publication bias outcomes.

CONCLUSION

Our meta-analysis suggests that MT may be not associated with functional prognosis of mild AIS with LVO.

Clinical protocol of the ischemic stroke patients treatment

Today in Ukraine there is no single standardized protocol for the treatment of patients in the acute period of ischemic stroke using modern methods of diagnosis and treatment, which include thrombolytic therapy and endovascular treatment. This protocol was created and implemented in Scientific-practical Center of endovascular neuroradiology, NAMS of Ukraine and is based on the latest recommendations of AHA/ASA and ESO, as well as registers of patients with ischemic stroke. The main purpose of this publication is the creation and implementation of «instructions» for the diagnosis and selection of objective tactics for treating patients in the acute period of ischemic stroke.

Mechanical Thrombectomy in Patients Presenting with NIHSS Score <6: A Safety and Efficacy Analysis

BACKGROUND AND OBJECTIVES

Groundbreaking trials have shown the tremendous efficacy of mechanical thrombectomy for large vessel occlusions. Currently, mechanical thrombectomy is limited to patients with NIHSS scores ≥6. We investigated the feasibility and safety of MT in patients presenting with NIHSS scores <6.

MATERIALS AND METHODS

A retrospective review of patient who presented with acute ischemic stroke due to large vessel occlusion with an NIHSS score <6 between 2015 - 2021. The patients were then divided into two groups: those who received mechanical thrombectomy and those who did not.

RESULTS

Among 83 patients, 41 received a mechanical thrombectomy while 42 received medical treatment only. The mean age in the mechanical thrombectomy group was 66 years versus 60 years in the medical group (p = 0.06). Risk factors for stroke did not differ significantly between both groups. 14 patients (34.1%) in the mechanical thrombectomy group and 20 (47.6%) in the medical group received tissue plasminogen activator. No significant difference in clinical improvement (NIHSS) at discharge (p=0.85) or the mRS score at 90 days (p = 0.15) was noted. Mechanical thrombectomy was associated with smaller infarct size (p=0.04) and decreased mortality (p=0.03).

CONCLUSIONS

Mechanical thrombectomy is safe and effective for patients who present with large vessel occlusions and low initial NIHSS scores. Therefore, the decision to offer the patient mechanical thrombectomy or not should not be decided by NIHSS score alone. Rather, the decision should be multifactorial with the aim of maximizing the patients' outcomes.

A regional strategy to decrease the time to thrombectomy in patients with low probability of treatment by thrombolysis

BACKGROUND AND PURPOSE

The best transportation strategy for patients with suspected large vessel occlusion (LVO) is unknown. Here, we evaluated a new regional strategy of direct transportation to a Comprehensive Stroke Center (CSC) for patients with suspected LVO and low probability of receiving intravenous thrombolysis (IVT) at the nearest Primary Stroke Center (PSC).

METHODS

Patients could be directly transported to the CSC (bypass group) if they met our pre-hospital bypass criteria: high LVO probability (i.e., severe hemiplegia) with low IVT probability (contraindications) and/or travel time difference between CSC and PSC<15 minutes. The other patients were transported to the PSC according to a "drip-and-ship" strategy. Treatment time metrics were compared in patients with pre-hospital bypass criteria and confirmed LVO in the bypass and drip-and-ship groups.

RESULTS

In the bypass group (n=79), 54/79 (68.3%) patients met the bypass criteria and 29 (36.7%) had confirmed LVO. The positive predictive value of the hemiplegia criterion for LVO detection was 0.49. In the drip-and-ship group (n=457), 92/457 (20.1%) patients with confirmed LVO met our bypass criteria. Among the 121 patients with bypass criteria and confirmed LVO, direct routing decreased the time between symptom discovery and groin puncture by 55 minutes compared with the drip-and-ship strategy (325 vs. 229 minutes, P<0.001), without significantly increasing the time to IVT (P=0.19).

CONCLUSIONS

Our regional strategy led to the correct identification of LVO and a significant decrease of the time to mechanical thrombectomy, without increasing the time to IVT, and could be easily implemented in other territories.

Mechanical thrombectomy in acute ischemic stroke due to large vessel occlusion in the anterior circulation and low baseline National Institute of Health Stroke Scale score: a multicenter retrospective matched analysis

BACKGROUND AND PURPOSE

The benefit of mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) and baseline mild neurological symptoms remains unclear. The purpose of this study was to evaluate the effectiveness of MT in this subgroup of patients.

METHODS

The databases of 9 high-volume Italian stroke centers were retrospectively screened for patients with LVO in the anterior circulation and a baseline National Institute of Health Stroke Scale (NIHSS) score ≤ 5 that received either immediate MT or best medical management (BMM) with the possibility of rescue MT upon neurological worsening. Primary outcome measure was a modified Rankin Scale score of 0-1 at 90 days. Propensity score matching (PSM) analysis was used to estimate the treatment effect of immediate MT compared to BMM/rescue MT.

RESULTS

Two hundred and seventy-two patients received immediate MT (MT group). The BMM/rescue MT group included 41 patients. The primary outcome was achieved in 78.6% (n = 246) of overall patients, with a higher proportion in the MT group (80.5% vs. 65.9%, p = 0.03) in unadjusted analysis. After PSM, patients in the MT group had a 19.5% higher chance of excellent outcome at 90 days compared to the BMM/Rescue MT group with a similar risk of death from any cause.

CONCLUSIONS

Our experience is in favor of a potential benefit of MT also in patients with LVO and a NIHSS score ≤ 5 at the time of groin puncture. Nonetheless, this issue waits for a clear-cut recommendation in a dedicated clinical trial.

Mechanical Thrombectomy for Acute Stroke Due to Large-Vessel Occlusion Presenting With Mild Symptoms

Purpose: To evaluate the safety and efficacy of mechanical thrombectomy (MT) for acute stroke due to large vessel occlusion (LVO), presenting with mild symptoms.

Methods: A prospective cohort study of patients with mild ischemic stroke and LVO was conducted. Patients were divided into two groups: MT group or best medical management (MM) group. Propensity score matching (PSM) was conducted to reduce the confounding bias between the groups. The primary outcome was functional independence at 90 days. The safety outcome was symptomatic intracranial hemorrhage (sICH). Univariate and multivariate logistic regression analyses were used to identify the independent factors associated with outcomes.

Results: Among the 105 included patients, 43 were in the MT group and 62 in the MM group. Forty-three pairs of patients were generated after PSM. There were no significant differences in sICH rates between two groups (p = 1.000). The MT group had a higher proportion of independent outcomes (83.7% MT vs. 67.4% MM; OR 2.483; 95% CI 0.886–6.959; p = 0.079) and excellent outcomes (76.7% MT vs. 51.2% MM; OR 3.150; 95% CI 1.247–7.954; p = 0.013) compared to the MM group, especially in patients with stroke of the anterior circulation (p < 0.05). Multivariate logistic regression analysis showed that small infarct core volume (p = 0.015) and MT treatment (p = 0.013) were independently associated with excellent outcomes.

Conclusions: Our results suggest that MT in stroke patients, presenting with mild symptoms, due to acute LVO in the anterior circulation may be associated with satisfactory clinical outcomes.

Clinical Trial Registration:ClinicalTrials.gov, identifier: NCT04526756.

Radiographic Characteristics of Mild Ischemic Stroke Patients With Visible Intracranial Occlusion: The INTERRSeCT Study

BACKGROUND AND PURPOSE

Early neurological deterioration occurs in one-third of mild strokes primarily due to the presence of a relevant intracranial occlusion. We studied vascular occlusive patterns, thrombus characteristics, and recanalization rates in these patients.

METHODS

Among patients enrolled in INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography), a multicenter prospective study of acute ischemic strokes with a visible intracranial occlusion, we compared characteristics of mild (National Institutes of Health Stroke Scale score, ≤5) to moderate/severe strokes.

RESULTS

Among 575 patients, 12.9% had a National Institutes of Health Stroke Scale score ≤5 (median age, 70.5 [63-79]; 58% male; median National Institutes of Health Stroke Scale score, 4 [2-4]). Demographics and vascular risk factors were similar between the two groups. As compared with those with a National Institutes of Health Stroke Scale score >5, mild patients had longer symptom onset to assessment times (onset to computed tomography [240 versus 167 minutes] and computed tomography angiography [246 versus 172 minutes]), more distal occlusions (M3, anterior cerebral artery and posterior cerebral artery; 22% versus 6%), higher clot burden score (median, 9 [6-9] versus 6 [4-9]), similar favorable thrombus permeability (residual flow grades I-II, 21% versus 19%), higher collateral flow (9.1 versus 7.6), and lower intravenous alteplase treatment rates (55% versus 85%). Mild patients were more likely to recanalize (revised arterial occlusion scale score 2b/3, 45%; 49% with alteplase) compared with moderate/severe strokes (26%; 29% with alteplase). In an adjusted model for sex, alteplase, residual flow, and time between the two vessel imagings, intravenous alteplase use (odds ratio, 3.80 [95% CI, 1.11-13.00]) and residual flow grade (odds ratio, 8.70 [95% CI, 1.26-60.13]) were associated with successful recanalization among mild patients.

CONCLUSIONS

Mild strokes with visible intracranial occlusions have different vascular occlusive patterns but similar thrombus permeability compared with moderate/severe strokes. Higher thrombus permeability and alteplase use were associated with successful recanalization, although the majority do not recanalize. Randomized controlled trials are needed to assess the efficacy of new thrombolytics and endovascular therapy in this population.

Acute Stroke With Large Vessel Occlusion and Minor Clinical Deficits: Prognostic Factors and Therapeutic Implications

Background and Purpose: The optimal acute management of patients with large vessel occlusion (LVO) and minor clinical deficits on admission [National Institutes of Health Stroke Scale (NIHSS) ≤ 4] remains to be elucidated. The aim of the present study was to investigate the prognostic factors and therapeutic management of those patients.

Methods: In this retrospective cohort study, we investigated (1) all patients with acute ischemic stroke due to an LVO who underwent mechanical thrombectomy (MT) and (2) all patients with minor clinical deficits (NIHSS ≤ 4) on admission due to an LVO between January 2013 and December 2016 at the University Medical Center Erlangen. We dichotomized management of patients with minor deficits treated with MT for analysis according to immediate mechanical thrombectomy (IT) and initial medical management with rescue intervention (MM) in case of secondary deterioration. Primary endpoints were secondary deterioration, in-hospital mortality, and functional outcome on day 90 (dichotomized modified Rankin Scale 0–2: favorable, 3–6: poor).

Results: Two hundred twenty-three patients (83% with anterior circulation stroke, 13 (6%) with minor deficits) treated with MT and 88 patients with minor deficits due to LVO [13 (15%) treated with MT] were included. Secondary deterioration (n = 19) was independently associated with poor outcome in patients with minor deficits and LVO [odds ratio (OR), 0.060; 95% confidence interval (CI), 0.013–0.280], which in turn was associated with the occlusion site [especially M1 occlusion: 11 (58%) vs. 3 (4%) in patients without secondary deterioration, p < 0.0001]. IT (n = 8) was associated with a lower intrahospital mortality compared to MM (n = 5; 13 vs. 80%; OR, 0.036; 95% CI, 0.002–0.741). Seven of eight patients with IT survived until discharge, with 29% showing a favorable functional outcome on day 90.

Conclusions: Secondary deterioration is associated with poor outcome in patients with LVO and minor deficits, which in turn was associated with occlusion site. Future randomized controlled trials should assess whether selected patients, depending on occlusion site and associated characteristics, may benefit from MT.

Treatment Challenges in Acute Minor Ischemic Stroke

Patients with acute ischemic stroke may present with minor neurologic deficits. Acute treatment decisions depend on the disability imposed by the symptoms along with radiographic features. The presence of disabling neurologic deficits warrants intravenous thrombolysis, but the indications for endovascular therapy are less defined. The degree of disability, presence of a large vessel occlusion with perfusion mismatch, and collateral circulation status may all be factors in selecting patients for endovascular treatment. Identification of patients who are at risk for neurologic deterioration is critical to preventing poor outcomes in this patient population.

Reasons for Not Performing Mechanical Thrombectomy: A Population-Based Study of Stroke Codes

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Endovascular Treatment of Acute Ischemic Stroke in Clinical Practice: Analysis of Workflow and Outcome in a Tertiary Care Center

Background and Purpose: Pre- and intra-hospital workflow in mechanical recanalization of large cervicocephalic arteries in patients with acute ischemic stroke still needs optimization. In this study, we analyze workflow and outcome in our routine care of stroke patients undergoing mechanical thrombectomy as a precondition for such optimization.

Methods: Processes of pre- and intra-hospital management, causes of treatment delay, imaging results (Alberta Stroke Program Early Computed Tomography Score, localization of vessel occlusion), recanalization (modified thrombolysis in cerebral infarction score), and patient outcome (modified Rankin scale at discharge and at the end of inpatient rehabilitation) were analyzed for all patients who underwent mechanical thrombectomy between April 1, 2016, and September 30, 2018, at our site.

Results: Finally, data of 282 patients were considered, of whom 150 (53%) had been referred from external hospitals. Recanalization success and patient outcome were similar to randomized controlled thrombectomy studies and registries. Delay in treatment occurred when medical treatment of a hypertensive crisis, epileptic fits, vomiting, or agitation was mandatory but also due to missing prenotification of the hospital emergency staff by the rescue service, multiple mode or repeated brain imaging, and transfer from another hospital. Even transfer from external hospitals located within a 10-km radius of our endovascular treatment center led to a median increase of the onset-to-groin time of ~60 min.

Conclusion: The analysis revealed several starting points for an improvement in the workflow of thrombectomy in our center. Analyses of workflow and treatment results should be carried out regularly to identify the potential for optimization of operational procedures and selection criteria for patients who could benefit from endovascular treatment.

Prediction of Early Neurological Deterioration in Individuals With Minor Stroke and Large Vessel Occlusion Intended for Intravenous Thrombolysis Alone

Importance

The best reperfusion strategy in patients with acute minor stroke and large vessel occlusion (LVO) is unknown. Accurately predicting early neurological deterioration of presumed ischemic origin (ENDi) following intravenous thrombolysis (IVT) in this population may help to select candidates for immediate transfer for additional thrombectomy.

Objective

To develop and validate an easily applicable predictive score of ENDi following IVT in patients with minor stroke and LVO.

Design, Setting, and Participants

This multicentric retrospective cohort included 729 consecutive patients with minor stroke (National Institutes of Health Stroke Scale [NIHSS] score of 5 or less) and LVO (basilar artery, internal carotid artery, first [M1] or second [M2] segment of middle cerebral artery) intended for IVT alone in 45 French stroke centers, ie, including those who eventually received rescue thrombectomy because of ENDi. For external validation, another cohort of 347 patients with similar inclusion criteria was collected from 9 additional centers. Data were collected from January 2018 to September 2019.

Main Outcomes and Measures

ENDi, defined as 4 or more points' deterioration on NIHSS score within the first 24 hours without parenchymal hemorrhage on follow-up imaging or another identified cause.

Results

Of the 729 patients in the derivation cohort, 335 (46.0%) were male, and the mean (SD) age was 70 (15) years; of the 347 patients in the validation cohort, 190 (54.8%) were male, and the mean (SD) age was 69 (15) years. In the derivation cohort, the median (interquartile range) NIHSS score was 3 (1-4), and the occlusion site was the internal carotid artery in 97 patients (13.3%), M1 in 207 (28.4%), M2 in 395 (54.2%), and basilar artery in 30 (4.1%). ENDi occurred in 88 patients (12.1%; 95% CI, 9.7-14.4) and was strongly associated with poorer 3-month outcomes, even in patients who underwent rescue thrombectomy. In multivariable analysis, a more proximal occlusion site and a longer thrombus were independently associated with ENDi. A 4-point score derived from these variables-1 point for thrombus length and 3 points for occlusion site-showed good discriminative power for ENDi (C statistic = 0.76; 95% CI, 0.70-0.82) and was successfully validated in the validation cohort (ENDi rate, 11.0% [38 of 347]; C statistic = 0.78; 95% CI, 0.70-0.86). In both cohorts, ENDi probability was approximately 3%, 7%, 20%, and 35% for scores of 0, 1, 2 and 3 to 4, respectively.

Conclusions and Relevance

The substantial ENDi rates observed in these cohorts highlights the current debate regarding whether to directly transfer patients with IVT-treated minor stroke and LVO for additional thrombectomy. Based on the strong associations observed, an easily applicable score for ENDi risk prediction that may assist decision-making was derived and externally validated.

Thrombectomy for Basilar Artery Occlusion with Mild Symptoms

BACKGROUND AND OBJECTIVE

To evaluate outcomes of thrombectomy in patients with a basilar artery occlusion (BAO) and mild symptoms, defined by an initial National Institutes of Health Stroke Scale (NIHSS) score ≤6.

METHODS

We performed a retrospective analysis of a multicenter prospective cohort of consecutive patients with acute ischemic stroke with BAO who underwent thrombectomy. We compared baseline and procedural characteristics, as well as outcomes between patients with BAO with an NIHSS score ≤6 and >6. Multivariate analyses were performed to determine baseline and procedural predictors of good outcome (modified Rankin Scale score 0-2) among patients with an NIHSS score ≤6.

RESULTS

A total of 269 patients were included: 50 (19%) had an initial NIHSS score ≤6 and 219 (81%) had an NIHSS score >6. Patients with mild strokes (NIHSS score ≤6) had better outcomes (68% of modified Rankin Scale score 0-2 vs. 27% for NIHSS score >6; P < 0.0001), lower mortality (14% vs. 48; P < 0.0001) and fewer parenchymal hematomas at day 1 (0% vs. 10%; P = 0.016). A multivariate analysis identified the following predictors for good outcome among patients with BAO with an NIHSS score ≤6: younger age, fewer passes, a cardioembolic cause, and the absence of need for angioplasty/stenting.

CONCLUSIONS

Thrombectomy seems to be safer and more effective for mild BAO strokes with NIHSS score ≤6 than for more severe patients. Even although thrombectomy showed high rates of recanalization, a substantial proportion (32%) nevertheless had a poor long-term clinical outcome. The number of passes, patient's age, and stroke cause seem to be predictors of clinical outcome.

Perfusion and Diffusion Variables Predict Early Neurological Deterioration in Minor Stroke and Large Vessel Occlusion

Background and Purpose

Patients with acute large vessel occlusion (LVO) presenting with mild stroke symptoms are at risk of early neurological deterioration (END). This study aimed to identify the optimal imaging variables for predicting END in this population.

Methods

We retrospectively analyzed 94 patients from the prospectively maintained institutional stroke registry admitted between January 2011 and May 2019, presenting within 24 hours after onset, with a baseline National Institutes of Health Stroke Scale score ≤5 and anterior circulation LVO. Patients who underwent endovascular therapy before END were excluded. Volumes of Tmax delay (at >2, >4, >6, >8, and >10 seconds), mismatch (Tmax >4 seconds – diffusion-weighted imaging [DWI] and Tmax >6 seconds – DWI), and mild hypoperfusion lesions (Tmax 2–6 and 4–6 seconds) were measured. The association of each variable with END was examined using receiver operating characteristic curves. The variables with best predictive performance were dichotomized at the cutoff point maximizing Youden’s index and subsequently analyzed using multivariable logistic regression.

Results

END occurred in 39.4% of the participants. The optimal variables were identified as Tmax >6 seconds, Tmax >6 seconds – DWI, and Tmax 4–6 seconds with cut-off points of 53.73, 32.77, and 55.20 mL, respectively. These variables were independently associated with END (adjusted odds ratio [aOR], 12.78 [95% confidence interval (CI), 3.36 to 48.65]; aOR, 5.73 [95% CI, 2.04 to 16.08]; and aOR, 9.13 [95% CI, 2.76 to 30.17], respectively).

Conclusions

Tmax >6 seconds, Tmax >6 seconds – DWI, and Tmax 4–6 seconds could identify patients at high risk of END following minor stroke due to LVO.

Microbleeds, Cerebral Hemorrhage, and Functional Outcome After Endovascular Thrombectomy

OBJECTIVE

To determine whether pretreatment cerebral microbleeds (CMBs) presence and burden are correlated with an increased risk of intracranial hemorrhage (ICH) or poor functional outcome following endovascular thrombectomy (EVT) for acute ischemic stroke (AIS).

METHODS

Consecutive patients treated by EVT for anterior circulation AIS were retrospectively analyzed. Experienced neuroradiologists blinded to functional outcomes rated CMBs on T2*-MRI using a validated scale. We investigated associations of CMB presence and burden with ICH and poor clinical outcome at 3 months (modified Rankin Scale score >2).

RESULTS

Among 513 patients, 281 (54.8%) had a poor outcome and 89 (17.3%) had ≥1 CMBs. A total of 190 (37%) patients experienced ICH; 66 (12.9%) were symptomatic. CMB burden was associated with poor outcome in a univariable analysis (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.03-1.36 per 1-CMB increase; p = 0.02), but significance was lost after adjustment for sex, age, stroke severity, hypertension, diabetes mellitus, atrial fibrillation, prior antithrombotic medication, IV thrombolysis, and reperfusion status (OR, 1.05; 95% CI, 0.92-1.20 per 1-CMB increase; p = 0.50). Results remained nonsignificant when taking into account CMB location or presumed underlying pathogenesis. CMB presence, burden, location, or presumed pathogenesis were not independently correlated with ICH.

CONCLUSIONS

Poor functional outcome or ICH were not correlated with CMB presence or burden on pre-EVT MRI after adjustment for confounding factors. Excluding such patients from reperfusion therapies is unwarranted.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with AIS undergoing EVT, after adjustment for confounding factors, the presence of CMBs is not significantly associated with clinical outcome or the risk of ICH.

Impact of recanalisation by mechanical thrombectomy in mild acute ischemic stroke with large anterior vessel occlusion

BACKGROUND

The net clinical benefit of mechanical thrombectomy (MT) in patients presenting acute anterior circulation ischemic stroke with large-vessel occlusion (AIS-LVO) and mild neurological deficit is uncertain.

AIMS

To investigate efficacy and safety of MT in patients with acute AIS-LVO and mild neurological deficit by evaluating i) the influence of recanalisation on three-month outcome and ii) mortality, symptomatic intracerebral hemorrhage (sICH) and procedural complications.

METHODS

We included consecutive patients with acute AIS-LVO and National Institute of Stroke Scale (NIHSS) score<8, treated by MT at Lille University Hospital. Recanalisation was graded according to modified thrombolysis in cerebral infarction (mTICI) score, mTICI 2b/2c/3 being considered successful. We recorded procedural complications and classified intra-cerebral hemorrhages (ICH) and sICH according with European Cooperative Acute Stroke Study (ECASS) and ECASS2 criteria. Three-month outcome was evaluated by modified Rankin scale (mRS). Excellent and favourable outcomes were respectively defined as mRS 0-1 and 0-2 (or similar to pre-stroke).

RESULTS

We included 95 patients. At three months, 56 patients (59. 0%) achieved an excellent outcome and 69 (72, 6%) a favourable outcome, both being more frequent in patients with successful recanalisation than in patients without (excellent outcome 71, 1% versus 10, 5%, P<0.001 and favourable outcome 82.9% versus 31.6%, P<0.001). The difference remained unchanged after adjustment for age and pre-MT infarct volume. Similar results were observed in patients with pre-MT NIHSS ≤5. Death occurred in five patients (5.3%), procedural complications in 12 (12.6%), any ICH in 38 (40.0%), including 3 (3.2%) sICH.

CONCLUSIONS

Achieving successful recanalisation appears beneficial and safe in acute AIS-LVO patients with NIHSS<8 before MT.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

Outcomes after Thrombectomy for Minor Stroke: A Meta-Analysis

PURPOSE

To determine the outcomes after mechanical thrombectomy (MT) versus medical management in patients with minor stroke symptomatology.

METHODS

A meta-analysis was performed for studies reporting outcomes after MT, either as stand-alone therapy or with intravenous thrombolysis in patients with minor stroke and large-vessel occlusion.

RESULTS

Fourteen studies with 2134 patients met the selection criteria and were included. Two studies compared immediate thrombectomy versus best medical management (with rescue thrombectomy) and the odds ratios of excellent outcomes, good outcomes, mortality and incidence of symptomatic intracranial hemorrhage (sICH) after immediate thrombectomy versus best medical management were 1.07 (95% confidence interval [CI] 0.93-1.22%), 1.15 (95% CI 1.05-1.25), 0.65 (95% CI 0.30-1.38), and 2.89 (95% CI 0.82-10.13), respectively. Among the 8 studies that compared MT outcomes versus medical management (without thrombectomy), odds ratios of excellent outcomes, good outcomes, mortality, and incidence of sICH after MT versus medical management were 0.98 (95% CI 0.89-1.07), 0.94 (95% CI 0.89-1.00), 1.61 (95% CI 1.08-2.41), and 2.59 (95% CI 1.35-4.96), respectively. Among all 14 studies, pooled proportions of excellent outcomes, good outcomes, mortality, and sICH after thrombectomy were 58.7%, 76.2%, 6.82%, and 3.23%, respectively.

CONCLUSIONS

Our study shows significant selection bias and heterogeneity in the literature with differences in baseline characteristics (age, stroke severity, prestroke modified Rankin Scale score, side of infarct, vessel and site of occlusion, use of intravenous thrombolysis, criteria for clinical deterioration, and selection bias for rescue MT and rates of reperfusion), emphasizing the need for a randomized controlled trial.

Medical Management vs Mechanical Thrombectomy for Mild Strokes: An International Multicenter Study and Systematic Review and Meta-analysis

Importance

The benefit of mechanical thrombectomy (MT) in patients with stroke presenting with mild deficits (National Institutes of Health Stroke Scale [NIHSS] score <6) owing to emergency large-vessel occlusion (ELVO) remains uncertain.

Objective

To assess the outcomes of patients with mild-deficits ELVO (mELVO) treated with MT vs best medical management (bMM).

Data Sources

We retrospectively pooled patients with mELVO during a 5-year period from 16 centers. A meta-analysis of studies reporting efficacy and safety outcomes with MT or bMM among patients with mELVO was also conducted. Data were analyzed between 2013 and 2017.

Study Selection

We identified studies that enrolled patients with stroke (within 24 hours of symptom onset) with mELVO treated with MT or bMM.

Main Outcomes and Measures

Efficacy outcomes included 3-month favorable functional outcome and 3-month functional independence that were defined as modified Rankin Scale scores of 0 to 1 and 0 to 2, respectively. Safety outcomes included 3-month mortality and symptomatic and asymptomatic intracranial hemorrhage (ICH).

Results

We evaluated a total of 251 patients with mELVO who were treated with MT (n = 138; 65 women; mean age, 65.2 years; median NIHSS score, 4; interquartile range [IQR], 3-5) or bMM (n = 113; 51 women; mean age, 64.8; median NIHSS score, 3; interquartile range [IQR], 2-4). The rate of asymptomatic ICH was lower in bMM (4.6% vs 17.5%; P = .002), while the rate of 3-month FI (after imputation of missing follow-up evaluations) was lower in MT (77.4% vs 88.5%; P = .02). The 2 groups did not differ in any other efficacy or safety outcomes. In multivariable analyses, MT was associated with higher odds of asymptomatic ICH (odds ratio [OR], 11.07; 95% CI, 1.31-93.53; P = .03). In the meta-analysis of 4 studies (843 patients), MT was associated with higher odds of symptomatic ICH in unadjusted analyses (OR, 5.52; 95% CI, 1.91-15.49; P = .002; I2 = 0%). This association did not retain its significance in adjusted analyses including 2 studies (OR, 2.06; 95% CI, 0.49-8.63; P = .32; I2 = 0%). The meta-analysis did not document any other independent associations between treatment groups and safety or efficacy outcomes.

Conclusions and Relevance

Our multicenter study coupled with the meta-analysis suggests similar outcomes of MT and bMM in patients with stroke with mELVO, but no conclusions about treatment effect can be made. The clinical equipoise can further be resolved by a randomized clinical trial.