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.

Endovascular treatment versus medical management for mild stroke with acute anterior circulation large vessel occlusion: a meta-analysis

BACKGROUND

The effectiveness of endovascular treatment (EVT) in patients with mild stroke (National Institutes of Health Stroke Scale score ≤5) and acute anterior circulation large vessel occlusion (AACLVO) remains unknown.

OBJECTIVE

To conduct a meta-analysis to compare the efficacy and safety of EVT in patients with mild stroke and AACLVO.

METHODS

EMBASE, Cochrane Library, PubMed, and Clinicaltrials.gov databases were searched until October 2022. Both retrospective and prospective studies which compared the clinical outcomes between EVT and medical treatment were included. ORs and 95% confidence intervals (CIs) for excellent and favorable functional outcomes, symptomatic intracranial hemorrhage (ICH), and mortality were pooled using a random-effects model. A propensity score (PS)-based methods adjusted analysis was also performed.

RESULTS

4335 patients from 14 studies were included. In patients with mild stroke and AACLVO, EVT presented no marked differences in excellent and favorable functional outcomes and mortality compared with medical treatment. A higher risk of symptomatic ICH (OR=2.79; 95% CI 1.49 to 5.24; P=0.001) was observed with EVT. Subgroup analysis revealed that EVT had potential benefit for proximal occlusions with excellent functional outcomes (OR=1.68; 95% CI 1.01 to 2.82; P=0.05). Similar results were observed when PS-based methods adjusted analysis was used.

CONCLUSION

EVT did not significantly benefit clinical functional outcomes in comparison with medical treatment in patients with mild stroke and AACLVO. However, it may improve functional outcomes when treating patients with proximal occlusion, despite being associated with an increased risk of symptomatic ICH. Stronger evidence from ongoing randomized controlled trials is required.

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.

Safety and efficacy of endovascular recanalization in patients with mild anterior stroke due to large-vessel occlusion exceeding 24 hours

BACKGROUND

Endovascular recanalization (ER) has demonstrated efficacy as a treatment modality for patients presenting with acute ischemic stroke (AIS) caused by large-vessel occlusion (LVO) within a 24-hour timeframe. Nevertheless, the safety and effectiveness of ER in patients with a time of onset exceeding 24 h remain uncertain.

OBJECTIVE

To evaluate the safety and efficacy of ER treatment for mild ischemic stroke beyond 24-h from symptom onset.

METHODS

A retrospectively maintained database of mild AIS due to LVO from March2018 to September 2022 at a comprehensive stroke center was screened.Patients received ER or standard medical therapies (SMT) for anterior circulation AIS due to LVO > 24-h were selected.

RESULTS

We included 47 LVO patients with mild AIS beyond 24-h who suffered neurological deterioration (ND). 34 of these patients underwent ER, the other 13 received SMT. The technical success rate of recanalization was 82.4% (28/34). Patients received ER had significantly lower NIHSS score at discharge and 90-day mRS score (p = 0.028, p = 0.037, respectively) compared to SMT. In addition, they had significantly lower 90-day recurrence of ischemic stroke and lower incidence of moderate-severe stroke (with a NIHSS score at least 5) (p = 0.037, p = 0.033). There were 4 patients (11.7%) had perioperative complications, and no symptomatic intracranial hemorrhage occurred.

CONCLUSION

ER treatment for mild AIS due to LVO encountered ND was generally safe and effective, even beyond 24-h, and resulted in a good prognosis and lower 90-day recurrence compared to SMT.

Intravenous Thrombolysis or Medical Management for Minor Strokes

OBJECTIVE

 To evaluate the outcomes of acute ischemic stroke patients with minor deficits treated with either intravenous thrombolysis (IVT) or routine medical management (MM).

METHODS

 The study included patients with acute ischemic stroke and National Institutes of Health Stroke Scale (NIHSS) scores of 5 or less who were treated with IVT within 4.5 hours from symptom onset and were classified as the IVT group. The MM group consisted of an equal number of patients with minor strokes, matched for sex, age, and severity, who did not receive thrombolysis. Data on patient information were collected for both groups.

RESULTS

 A total of 26,236 patients were included in this study (13,208 in IVT and 13,208 in MM). Of these patients, 67.9% were men, and the mean age was 67.1 years (standard deviation: 10.9). At 3 months, the IVT group had a higher rate of stroke-independent outcome (Rankin Scale score of 0-2) compared with the MM group (IVT vs. MM: 91.6 vs. 88.6%, absolute difference: 2.5%, 95% confidence interval [CI]: 1.6-3.4%, p = 0.008; adjusted hazard ratio [HR]: 1.2, 95% CI: 1.1-1.4, p = 0.003). Furthermore, there was no significant difference in 3-month mortality rates between the IVT and MM groups (IVT vs. MM: 2.1 vs. 2.5%, absolute difference: -0.6%, 95% CI: -1.1 to 0.3%, p = 0.11; adjusted HR: 0.9, 95% CI: 0.8-1.2, p = 0.09).

CONCLUSION

 Compared with MM, IVT does not reduce mortality in minor ischemic stroke but improves functional outcomes in minor stroke with an NIHSS score of 3 to 5.

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.

Outcomes after endovascular mechanical thrombectomy for low compared to high National Institutes of Health Stroke Scale (NIHSS): A multicenter study

OBJECTIVE

The role of endovascular mechanical thrombectomy (MT) in patients presenting with "minor" stroke is uncertain. We aimed to compare outcomes after MT for ischemic stroke patients presenting with National Institutes of Health Stroke Scale (NIHSS) 5 and - within the low NIHSS cohort - identify predictors of a favorable outcome, mortality, and symptomatic intracranial hemorrhage (ICH).

METHODS

We retrospectively analyzed a prospectively maintained, international, multicenter database.

RESULTS

The study cohort comprised a total of 7568 patients from 29 centers. NIHSS was low (<5) in 604 patients (8%), and > 5 in 6964 (92%). Patients with low NIHSS were younger (67 + 14.8 versus 69.6 + 14.7 years, p < 0.001), more likely to have diabetes (31.5% versus 26.9%, p = 0.016), and less likely to have atrial fibrillation (26.6% versus 37.6%, p < 0.001) compared to those with higher NIHSS. Radiographic outcomes (TICI > 2B 84.6% and 84.3%, p = 0.412) and complication rates (8.1% and 7.2%, p = 0.463) were similar between the low and high NIHSS groups, respectively. Clinical outcomes at every follow up interval, including NIHSS at 24 h and discharge, and mRS at discharge and 90 days, were better in the low NIHSS group, however patients in the low NIHSS group experienced a relative decline in NIHSS from admit to discharge. Mortality was lower in the low NIHSS group (10.4% versus 24.5%, p < 0.001).

CONCLUSIONS

Relative to patients with high NIHSS, MT is safe and effective for stroke patients with low NIHSS, and it is reasonable to offer it to appropriately selected patients presenting with minor stroke symptoms. Our findings justify efforts towards a randomized trial comparing MT versus medical management for patients with low NIHSS.

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.

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.

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.

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.

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.

Aspiration Thrombectomy in Patients with Large Vessel Occlusion and Mild Stroke: A Single-Center Experience

BACKGROUND The purpose of this study was to evaluate outcomes of patients with mild stroke, defined by National Institutes of Health Stroke Scale (NIHSS) score <6, caused by large vessel occlusion treated with aspiration thrombectomy. MATERIAL AND METHODS Data from the endovascular stroke registry of our center were retrospectively analyzed. Anterior or posterior circulation strokes with NIHSS score <6 upon admission were analyzed. The assessment of a good clinical outcome (modified Rankin scale score 0-2) at day 90 was the primary endpoint. Symptomatic intracranial hemorrhage, defined in European Cooperative Acute Stroke Study grade III, and mortality at day 90 were the safety measures. A successful endovascular procedure was defined as a Thrombolysis in Cerebral Infarction (TICI) score of 2b or 3. RESULTS We included 27 patients treated with immediate mechanical thrombectomy, 19 (70.4%) in the anterior circulation and 8 (29.6%) in the posterior circulation. The mean age was 69.8±12.3 years and 40.7% were male. Thirteen patients (48.1%) received bridging intravenous thrombolysis before endovascular thrombectomy. Twenty-five patients (92.6%) underwent the direct aspiration first-pass technique "ADAPT" as the first choice of endovascular procedure. Successful recanalization was achieved in 25 patients (92.6%). Twenty-one patients (77.8%) had a good functional outcome at the 3-month follow-up, 1 (3.7%) symptomatic intracranial hemorrhage was observed, and 2 patients (7.4%) died. CONCLUSIONS Immediate aspiration thrombectomy may be a safe and feasible first-line treatment option in patients suffering from mild stroke due to large vessel occlusion in the anterior and posterior circulation.

Computed Tomography-Based Imaging Algorithms for Patient Selection in Acute Ischemic Stroke

Computed tomography remains the most widely used imaging modality for evaluating patients with acute ischemic stroke. Landmark trials have used computed tomography imaging to select patients for intravenous thrombolysis and endovascular treatment. This review summarizes the most important acute ischemic stroke trials, provides an outlook of ongoing studies, and proposes possible image algorithms for patient selection. Although evaluation with anatomic computed tomography imaging techniques is sufficient in early window patients, more advanced imaging techniques should be used beyond 6 hours from symptoms onset to quantify the ischemic core and evaluate for the salvageable penumbra.

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.

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.

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.

Endovascular Therapy in Mild Ischemic Strokes Presenting Under 6 hours: An International Survey

BACKGROUND

Endovascular therapy (EVT) for patients with mild ischemic stroke (NIHSS ≤5) and visible intracranial occlusion remains controversial, including within 6 hours of symptom onset. We conducted a survey to evaluate global practice patterns of EVT in this population.

METHODS

Vascular stroke clinicians and neurointerventionalists were invited to participate through professional stroke listservs. The survey consisted of six clinical vignettes of mild stroke patients with intracranial occlusion. Cases varied by NIHSS, neurological symptoms and occlusion site. All had the same risk factors, time from symptom onset (5h) and unremarkable head CT. Advanced imaging data was available upon request. We explored independent case and responder specific factors associated with advanced imaging request and EVT decision.

RESULTS

A total of 482/492 responders had analyzable data ([median age 44 (IQR 11.25)], 22.7% women, 77% attending, 22% interventionalist). Participants were from USA (45%), Europe (32%), Australia (12%), Canada (6%), and Latin America (5%). EVT was offered in 48% (84% M1, 29% M2 and 19% A2) and decision was made without advanced imaging in 66% of cases. In multivariable analysis, proximal occlusion (M1 vs. M2 or A2, p<0.001), higher NIHSS (p<0.001) and fellow level training (vs. attending; p=0.001) were positive predictors of EVT. Distal occlusions (M2 and A2) and higher age of responders were independently associated with increased advanced imaging requests. Compared to US and Australian responders, Canadians were less likely to offer EVT, while those in Europe and Latin America were more likely (p<0.05).

CONCLUSIONS

Treatment patterns of EVT in mild stroke vary globally. Our data suggest wide equipoise exists in current treatment of this important subset of mild stroke.

More expansive horizons: a review of endovascular therapy for patients with low NIHSS scores

While the landmark 2015 stroke trials demonstrated that endovascular therapy (EVT) was superior to medical management for the treatment of acute ischemic stroke due to large vessel occlusion, the efficacy of EVT for patients presenting with a low NIHSS score remains undetermined. We conducted a review of the EVT low National Institutes of Health Stroke Scale (NIHSS) stroke literature, identifying 24 quantitative and six qualitative publications. Details of study designs and outcome were extracted and critically discussed.All identified qualitative studies were retrospective. There was significant study design heterogeneity, with 18 unique study designs between the 24 identified quantitative manuscripts. Study investigations included low NIHSS EVT feasibility (n=6), EVT versus best medical management (BMM; n=10), EVT versus intravenous therapy (IVT, n=3), and low NIHSS score versus high NIHSS score (n=3). From single-arm EVT feasibility studies, the reported ranges of modified Thrombolysis in Cerebral Infarction and symptomatic intracranial hemorrhage were 78-97% and 0-10%, respectively. The EVT versus BMM literature had heterogeneous results with 40% reporting benefit with EVT and 60% reporting neutral findings. None of the studies comparing EVT with IVT reported a difference between the two revascularization therapies. The four identified meta-analyses had incongruent inclusion criteria and conflicting results. Two randomized trials are currently investigating EVT in patients with a low NIHSS score. Selected meta-analyses do suggest a potential benefit of EVT over BMM; however, current and future randomized clinical trials will better elucidate the efficacy of EVT in this patient population.

Thrombectomy vs medical management in low NIHSS acute anterior circulation stroke

OBJECTIVE

To undertake an effectiveness and safety analysis of EVT in patients with LVO and NIH Stroke Scale (NIHSS) score ≤6 using datasets of multicenter and multinational nature.

METHODS

We pooled patients with anterior circulation occlusion from 3 prospective international cohorts. Patients were eligible if presentation occurred within 12 hours from last known well and baseline NIHSS ≤6. Primary outcome was modified Rankin Scale (mRS) score 0-1 at 90 days. Secondary outcomes included neurologic deterioration at 24 hours (change in NIHSS of ≥2 points), mRS 0-2 at 90 days, and 90-day all-cause mortality. We used propensity score matching to adjust for nonrandomized treatment allocation.

RESULTS

Among 236 patients who fit inclusion criteria, 139 received EVT and 97 received medical management. Compared to medical management, the EVT group was younger (65 vs 72 years; p < 0.001), had more proximal occlusions (p < 0.001), and less frequently received concurrent IV thrombolysis (57.7% vs 71.2%; p = 0.04). After propensity score matching, clinical outcomes between the 2 groups were not significantly different. EVT patients had an 8.6% (95% confidence interval [CI] -8.8% to 26.1%) higher rate of excellent 90-day outcome, despite a 22.3% (95% CI, 3.0%-41.6%) higher risk of neurologic deterioration at 24 hours.

CONCLUSIONS

EVT for LVO in patients with low NIHSS score was associated with increased risk of neurologic deterioration at 24 hours. However, both EVT and medical management resulted in similar proportions of excellent clinical outcomes at 90 days.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with acute anterior circulation ischemic strokes and LVO with NIHSS < 6, EVT and medical management result in similar outcomes at 90 days.

Endovascular Thrombectomy VS. Medical Treatment for Mild Stroke Patients: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

At present, endovascular thrombectomy (EVT) has been gradually became a standard therapy for stroke patients caused by emergent large-vessel occlusion (ELVO). However, the question about whether EVT is superior to medical treatment for mild stroke patients presenting with a low baseline National Institutes of Health Stroke Scale (NIHSS) score remains unclear. The aim of this systematic review and meta-analysis was to compare the safety and efficacy of EVT with medical treatment in mild stroke patients.

MATERIAL AND METHODS

A systematic review and meta-analysis was conducted through searching the PubMed, Embase and Cochrane Library databases. All statistical analyses were performed by using Review Manager 5.3 software. Primary outcomes of this meta-analysis were as follows: favorable functional outcome at 90 days (defined as a modified Rankin scale (mRS) score of 0-2); excellent functional outcome at 90 days (defined as a mRS score of 0-1); symptomatic intracerebral hemorrhage (sICH); mortality at 90 days.

RESULTS

A total of 13 eligible studies with 2135 patients were included in this meta-analysis. The pooled results indicated that mild stroke patients underwent EVT had higher risk of sICH than those receiving medical treatment alone (OR = 3.21; 95% CI, 1.98-5.22; P < 0.001). In addition, no significant difference was found between the two groups in mortality at 90 days (OR = 1.80; 95% CI, 0.88-3.65; P=0.11). Meanwhile, no significant difference was found between the two groups in patients achieving favorable functional outcome at 90 days and excellent functional outcome at 90 days (OR = 1.10; 95% CI, 0.74-1.64; P = 0.65) (OR = 1.03; 95% CI, 0.79-1.35; P = 0.80).

CONCLUSIONS

Our pooled results showed similar clinical outcomes at 90 days of EVT and medical treatment in mild stroke patients with ELVO, although patients underwent EVT had higher rates of sICH. However, due to several limitations of this meta-analysis, randomized controlled trials are needed to further evaluate the potential efficacy of EVT in mild stroke patients.

Is Endovascular Treatment Still Good for Ischemic Stroke in Real World?: A Meta-Analysis of Randomized Control Trial and Observational Study in the Last Decade

BACKGROUND AND PURPOSE

Although endovascular treatment (EVT) for acute ischemic stroke is classified as I evidence, outcomes after EVT in real-world practice appear to be less superior than those in randomized clinical trials (RCTs). Additionally, the effect of EVT is unclear compared with medical treatment (MT) for patients with mild symptoms defined by National Institutes of Health Stroke Scale score <6 or with severe symptoms defined by Alberta Stroke Program Early CT Score <6.

METHODS

Literatures were searched in big databases and major meetings from December 6, 2009, to December 6, 2019, including RCTs and observational studies comparing EVT against MT for patients with acute ischemic stroke. Observational studies were precategorized into 3 groups based on imaging data on admission: mild stroke group with National Institutes of Health Stroke Scale score <6, severe stroke group with Alberta Stroke Program Early CT Score <6 or ischemic core ≥50 mL, and normal stroke group for all others. Outcome was measured as modified Rankin Scale score of 0 to 2, mortality at 90 days, and symptomatic intracranial hemorrhage (sICH) at 24 hours.

RESULTS

Fifteen RCTs (n=3694) and 37 observational studies (n=9090) were included. EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality in RCTs and normal stroke group, whereas EVT was associated with higher sICH rate in normal stroke group, and no difference of sICH rate appeared between EVT and MT in RCTs. In severe stroke group, EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality, whereas no difference of sICH rate was found. In mild stroke group, there was no difference in modified Rankin Scale 0 to 2 rate between EVT and MT, whereas EVT was associated with higher mortality and sICH rate.

CONCLUSIONS

Evidence from RCTs and observational studies supports the use of EVT as the first-line choice for eligible patients corresponding to the latest guideline. For patients with Alberta Stroke Program Early CT Score <6, EVT showed superiority over MT, also in line with the guidelines. On the contrary to the guideline, our data do not support EVT for patients with National Institutes of Health Stroke Scale score <6.

Bridging Therapy or IV Thrombolysis in Minor Stroke with Large Vessel Occlusion

OBJECTIVE

Whether bridging therapy (intravenous thrombolysis [IVT] followed by endovascular treatment) is superior to IVT alone in minor stroke with large vessel occlusion (LVO) is unknown.

METHODS

Multicentric retrospective observational study including, in intention-to-treat, consecutive IVT-treated minor strokes (National Institutes of Health Stroke Scale [NIHSS] ≤ 5) with LVO, with or without additional mechanical thrombectomy. Propensity-score (inverse probability of treatment weighting) was used to reduce baseline between-groups differences. The primary outcome was excellent outcome, that is, modified Rankin score 0 to 1 at 3 months follow-up.

RESULTS

Overall, 598 patients were included (214 and 384 in the bridging therapy and IVT groups, respectively). Following propensity-score weighting, the distribution of baseline clinical and radiological variables was similar across the two patient groups. Compared with IVT alone, bridging therapy was not associated with excellent outcome (odds ratio [OR] = 0.96; 95% confidence interval [CI] = 0.75-1.24; p = 0.76), but was associated with symptomatic intracranial hemorrhage (OR = 3.01; 95% CI = 1.77-5.11; p < 0.0001). Occlusion site was a strong modifier of the effect of bridging therapy on outcome (p_interaction < 0.0001), with bridging therapy associated with higher odds of excellent outcome in proximal M1 (OR = 3.26; 95% CI = 1.67-6.35; p = 0.0006) and distal M1 (OR = 1.69; 95% CI = 1.01-2.82; p = 0.04) occlusions, but with lower odds of excellent outcome for M2 (OR = 0.53; 95% CI = 0.38-0.75; p = 0.0003) occlusions. Bridging therapy was associated with higher rates of symptomatic intracranial hemorrhage in M2 occlusions only (OR = 4.40; 95% CI = 2.20-8.83; p < 0.0001).

INTERPRETATION

Although overall outcomes were similar in intended bridging therapy as compared to intended IVT alone in minor strokes with LVO, our results suggest that intended bridging therapy may be beneficial in M1 occlusions, whereas the benefit-risk profile may favor IVT alone in M2 occlusions. ANN NEUROL 2020 ANN NEUROL 2020;88:160-169.