Endovascular treatment versus no endovascular treatment after 6-24 h in patients with ischaemic stroke and collateral flow on CT angiography (MR CLEAN-LATE) in the Netherlands: a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial.

BACKGROUND: Endovascular treatment for anterior circulation ischaemic stroke is effective and safe within a 6 h window. MR CLEAN-LATE aimed to assess efficacy and safety of endovascular treatment for patients treated in the late window (6-24 h from symptom onset or last seen well) selected on the basis of the presence of collateral flow on CT angiography (CTA). METHODS: MR CLEAN-LATE was a multicentre, open-label, blinded-endpoint, randomised, controlled, phase 3 trial done in 18 stroke intervention centres in the Netherlands. Patients aged 18 years or older with ischaemic stroke, presenting in the late window with an anterior circulation large-vessel occlusion and collateral flow on CTA, and a neurological deficit score of at least 2 on the National Institutes of Health Stroke Scale were included. Patients who were eligible for late-window endovascular treatment were treated according to national guidelines (based on clinical and perfusion imaging criteria derived from the DAWN and DEFUSE-3 trials) and excluded from MR CLEAN-LATE enrolment. Patients were randomly assigned (1:1) to receive endovascular treatment or no endovascular treatment (control), in addition to best medical treatment. Randomisation was web based, with block sizes ranging from eight to 20, and stratified by centre. The primary outcome was the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included all-cause mortality at 90 days after randomisation and symptomatic intracranial haemorrhage. All randomly assigned patients who provided deferred consent or died before consent could be obtained comprised the modified intention-to-treat population, in which the primary and safety outcomes were assessed. Analyses were adjusted for predefined confounders. Treatment effect was estimated with ordinal logistic regression and reported as an adjusted common odds ratio (OR) with a 95% CI. This trial was registered with the ISRCTN, ISRCTN19922220. FINDINGS: Between Feb 2, 2018, and Jan 27, 2022, 535 patients were randomly assigned, and 502 (94%) patients provided deferred consent or died before consent was obtained (255 in the endovascular treatment group and 247 in the control group; 261 [52%] females). The median mRS score at 90 days was lower in the endovascular treatment group than in the control group (3 [IQR 2-5] vs 4 [2-6]), and we observed a shift towards better outcomes on the mRS for the endovascular treatment group (adjusted common OR 1·67 [95% CI 1·20-2·32]). All-cause mortality did not differ significantly between groups (62 [24%] of 255 patients vs 74 [30%] of 247 patients; adjusted OR 0·72 [95% CI 0·44-1·18]). Symptomatic intracranial haemorrhage occurred more often in the endovascular treatment group than in the control group (17 [7%] vs four [2%]; adjusted OR 4·59 [95% CI 1·49-14·10]). INTERPRETATION: In this study, endovascular treatment was efficacious and safe for patients with ischaemic stroke caused by an anterior circulation large-vessel occlusion who presented 6-24 h from onset or last seen well, and who were selected on the basis of the presence of collateral flow on CTA. Selection of patients for endovascular treatment in the late window could be primarily based on the presence of collateral flow. FUNDING: Collaboration for New Treatments of Acute Stroke consortium, Dutch Heart Foundation, Stryker, Medtronic, Cerenovus, Top Sector Life Sciences & Health, and the Netherlands Brain Foundation.

Timing and causes of death after endovascular thrombectomy in patients with acute ischemic stroke.

Introduction: Endovascular thrombectomy (EVT) increases the chance of good functional outcome after ischemic stroke caused by a large vessel occlusion, but the risk of death in the first 90 days is still considerable. We assessed the causes, timing and risk factors of death after EVT to aid future studies aiming to reduce mortality. Patients and methods: We used data from the MR CLEAN Registry, a prospective, multicenter, observational cohort study of patients treated with EVT in the Netherlands between March 2014, and November 2017. We assessed causes and timing of death and risk factors for death in the first 90 days after treatment. Causes and timing of death were determined by reviewing serious adverse event forms, discharge letters, or other written clinical information. Risk factors for death were determined with multivariable logistic regression. Results: Of 3180 patients treated with EVT, 863 (27.1%) died in the first 90 days. The most common causes of death were pneumonia (215 patients, 26.2%), intracranial hemorrhage (142 patients, 17.3%), withdrawal of life-sustaining treatment because of the initial stroke (110 patients, 13.4%) and space-occupying edema (101 patients, 12.3%). In total, 448 patients (52% of all deaths) died in the first week, with intracranial hemorrhage as most frequent cause. The strongest risk factors for death were hyperglycemia and functional dependency before the stroke and severe neurological deficit at 24-48 h after treatment. Discussion and conclusion: When EVT fails to decrease the initial neurological deficit, strategies to prevent complications like pneumonia and intracranial hemorrhage after EVT could improve survival, as these are often the cause of death.

Association between type of intervention center and outcomes after endovascular treatment for acute ischemic stroke: Results from the MR CLEAN Registry.

Background: Endovascular treatment (EVT) for acute ischemic stroke (AIS) is performed in intervention centers that provide the full range of neuro(endo)vascular care (level 1) and centers that only perform EVT for AIS (level 2). We compared outcomes between these center types and assessed whether differences in outcomes could be explained by center volume (CV). Patients and methods: We analyzed patients included in the MR CLEAN Registry (2014-2018), a registry of all EVT-treated patients in the Netherlands. Our primary outcome was the shift on the modified Rankin scale (mRS) after 90 days (ordinal regression). Secondary outcomes were the NIHSS 24-48 h post-EVT, door-to-groin time (DTGT), procedure time (linear regression), and recanalization (binary logistic regression). We compared outcomes between level 1 and 2 centers using multilevel regression models, with center as random intercept. We adjusted for relevant baseline factors, and in case of observed differences, we additionally adjusted for CV. Results: Of the 5144 patients 62% were treated in level 1 centers. We observed no significant differences between center types in mRS (adjusted(a)cOR: 0.79, 95% CI: 0.40 to 1.54), NIHSS (aß: 0.31, 95% CI: -0.52 to 1.14), procedure duration (aß: 0.88, 95% CI: -5.21 to 6.97), or DTGT (aß: 4.24, 95% CI: -7.09 to 15.57). The probability for recanalization was higher in level 1 centers compared to level 2 centers (aOR 1.60, 95% CI: 1.10 to 2.33), and this difference probably depended on CV. Conclusions: We found no significant differences, that were independent of CV, in the outcomes of EVT for AIS between level 1 and level 2 intervention centers.

Etiology of Large Vessel Occlusion Posterior Circulation Stroke: Results of the MR CLEAN Registry.

BACKGROUND: In patients with large vessel occlusion stroke of the anterior circulation, underlying cause is a determinant of outcome. Whether this is the case for posterior circulation large vessel occlusion stroke has yet to be determined. We aimed to report on cause in patients with posterior circulation stroke treated with endovascular thrombectomy and to analyze the association with functional outcome. METHODS: We used data of patients with posterior circulation stroke included in the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) registry, a prospective multicenter observational study, between 2014 and 2018. Stroke cause was categorized into large artery atherosclerosis (LAA), cardioembolism, arterial dissection, embolic stroke of undetermined source (ESUS), other determined cause, or undetermined cause. For primary analysis on the association between cause and outcome, we used multivariable ordinal logistic regression analysis to estimate the adjusted common odds ratio for a shift towards a better functional outcome on the modified Rankin Scale at 90 days with LAA as a reference group. Secondary outcomes included favorable functional outcome (modified Rankin Scale score 0-3), National Institutes of Health Stroke Scale score at 24 to 48 hours, reperfusion on digital subtraction angiography, and stroke progression. RESULTS: Of 264 patients with posterior circulation stroke, 84 (32%) had LAA, 48 (18%) cardioembolism, 31 (12%) dissection, and 14 (5%) ESUS. Patients with a dissection were younger (48 [interquartile range, 43-60] years) and had a lower National Institutes of Health Stroke Scale at baseline (12 [interquartile range, 6-31]) than patients with other cause. Functional outcome was better for patients with cardioembolism and ESUS compared to LAA (modified Rankin Scale adjusted common odds ratio, 2.4 [95% CI, 1.1-5.2], respectively adjusted common odds ratio, 3.1 [95% CI, 1.0-9.3]). Patients with a dissection had a lower chance of successful reperfusion compared with LAA (adjusted odds ratio, 0.20 [95% CI, 0.06-0.70]). CONCLUSIONS: Unlike the anterior circulation, most frequent cause in our posterior large vessel occlusion stroke cohort is LAA followed by cardioembolism, dissection, and ESUS. Patients with cardioembolism and ESUS have a better prognosis for functional outcome after endovascular thrombectomy than patients with LAA.

Improvements in Endovascular Treatment for Acute Ischemic Stroke: A Longitudinal Study in the MR CLEAN Registry.

BACKGROUND: We evaluated data from all patients in the Netherlands who underwent endovascular treatment for acute ischemic stroke in the past 3.5 years, to identify nationwide trends in time to treatment and procedural success, and assess their effect on clinical outcomes. METHODS: We included patients with proximal occlusions of the anterior circulation from the second and first cohorts of the MR CLEAN (Multicenter Randomized Clinical trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry (March 2014 to June 2016; June 2016 to November 2017, respectively). We compared workflow times and rates of successful reperfusion (defined as an extended Thrombolysis in Cerebral Infarction score of 2B-3) between cohorts and chronological quartiles (all included patients stratified in chronological quartiles of intervention dates to create equally sized groups over the study period). Multivariable ordinal logistic regression was used to assess differences in the primary outcome (ordinal modified Rankin Scale at 90 days). RESULTS: Baseline characteristics were similar between cohorts (second cohort n=1692, first cohort n=1488) except for higher age, poorer collaterals, and less signs of early ischemia on computed tomography in the second cohort. Time from stroke onset to groin puncture and reperfusion were shorter in the second cohort (median 185 versus 210 minutes; P<0.001 and 236 versus 270 minutes; P<0.001, respectively). Successful reperfusion was achieved more often in the second than in the first cohort (72% versus 66%; P<0.001). Functional outcome significantly improved (adjusted common odds ratio 1.23 [95% CI, 1.07-1.40]). This effect was attenuated by adjustment for time from onset to reperfusion (adjusted common odds ratio, 1.12 [95% CI, 0.98-1.28]) and successful reperfusion (adjusted common odds ratio, 1.13 [95% CI, 0.99-1.30]). Outcomes were consistent in the analysis per chronological quartile. CONCLUSIONS: Clinical outcomes after endovascular treatment for acute ischemic stroke in routine clinical practice have improved over the past years, likely resulting from improved workflow times and higher successful reperfusion rates.

MR CLEAN-LATE, a multicenter randomized clinical trial of endovascular treatment of acute ischemic stroke in The Netherlands for late arrivals: study protocol for a randomized controlled trial.

BACKGROUND: Endovascular therapy (EVT) for acute ischemic stroke due to proximal occlusion of the anterior intracranial circulation, started within 6 h from symptom onset, has been proven safe and effective. Recently, EVT has been proven effective beyond the 6-h time window in a highly selected population using CT perfusion or MR diffusion. Unfortunately, these imaging modalities are not available in every hospital, and strict selection criteria might exclude patients who could still benefit from EVT. The presence of collaterals on CT angiography (CTA) may offer a more pragmatic imaging criterion that predicts possible benefit from EVT beyond 6 h from time last known well. The aim of this study is to assess the safety and efficacy of EVT for patients treated between 6 and 24 h from time last known well after selection based on the presence of collateral flow. METHODS: The MR CLEAN-LATE trial is a multicenter, randomized, open-label, blinded endpoint trial, aiming to enroll 500 patients. We will investigate the efficacy of EVT between 6 and 24 h from time last known well in acute ischemic stroke due to a proximal intracranial anterior circulation occlusion confirmed by CTA or MRA. Patients with any collateral flow (poor, moderate, or good collaterals) on CTA will be included. The inclusion of poor collateral status will be restricted to a maximum of 100 patients. In line with the current Dutch guidelines, patients who fulfill the characteristics of included patients in DAWN and DEFUSE 3 will be excluded as they are eligible for EVT as standard care. The primary endpoint is functional outcome at 90 days, assessed with the modified Rankin Scale (mRS) score. Treatment effect will be estimated with ordinal logistic regression (shift analysis) on the mRS at 90 days. Secondary endpoints include clinical stroke severity at 24 h and 5-7 days assessed by the NIHSS, symptomatic intracranial hemorrhage, recanalization at 24 h, follow-up infarct size, and mortality at 90 days, DISCUSSION: This study will provide insight into whether EVT is safe and effective for patients treated between 6 and 24 h from time last known well after selection based on the presence of collateral flow on CTA. TRIAL REGISTRATION: NL58246.078.17 , ISRCTN19922220 , Registered on 11 December 2017.

Effect of Heparinized Flush Concentration on Safety and Efficacy During Endovascular Thrombectomy for Acute Ischemic Stroke: Results from the MR CLEAN Registry.

BACKGROUND: Currently, there are no recommendations regarding the use of heparinized flush during endovascular thrombectomy (EVT) for acute ischemic stroke. Periprocedural heparin could, however, affect functional outcome and symptomatic intracranial hemorrhage (sICH). We surveyed protocols on heparin flush concentrations in Dutch EVT centers and assessed its effect on safety and efficacy outcomes. METHODS: Patients registered in the MR CLEAN Registry, from 2014 up to 2017 were included. We collected data on center protocols regarding heparin flush concentrations (IU/L) and grouped patients by their per protocol administered heparin flush concentration. We used a random effects model with random intercepts by EVT center and analyzed endpoints using regression models. Endpoints were sICH, mRS at 90 days, mortality and reperfusion rates. RESULTS: A total of 3157 patients were included of which 45% (6 centers) received no heparin in the flush fluids, 1.8% (1 center) received flush fluids containing 2000 IU/L heparin, 26% (4 centers) received 5000 IU/L, 22% (4 centers) received 10.000 IU/L and 5.6% (1 center) received 25.000 IU/L. Higher heparin concentration was associated with increased sICH (aOR 1.15; 95% CI 1.02-1.29), but not with functional outcome, mortality or reperfusion rates. CONCLUSION: Effect of heparin in flush fluids should not be ignored by clinicians or researchers as higher concentrations may be associated with higher rates of ICH. The observed variation in protocols regarding heparin concentrations between EVT centers should encourage further studies, ideally in a controlled way, resulting in recommendations on heparin use in flush fluids in future guidelines.

Improving quality of stroke care through benchmarking center performance: why focusing on outcomes is not enough.

BACKGROUND: Between-center variation in outcome may offer opportunities to identify variation in quality of care. By intervening on these quality differences, patient outcomes may be improved. However, whether observed differences in outcome reflect the true quality improvement potential is not known for many diseases. Therefore, we aimed to analyze the effect of differences in performance on structure and processes of care, and case-mix on between-center differences in outcome after endovascular treatment (EVT) for ischemic stroke. METHODS: In this observational cohort study, ischemic stroke patients who received EVT between 2014 and 2017 in all 17 Dutch EVT-centers were included. Primary outcome was the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death), at 90 days. We used random effect proportional odds regression modelling, to analyze the effect of differences in structure indicators (center volume and year of admission), process indicators (time to treatment and use of general anesthesia) and case-mix, by tracking changes in tau2, which represents the amount of between-center variation in outcome. RESULTS: Three thousand two hundred seventy-nine patients were included. Performance on structure and process indicators varied significantly between EVT-centers (P < 0.001). Predicted probability of good functional outcome (modified Rankin Scale 0-2 at 90 days), which can be interpreted as an overall measure of a center's case-mix, varied significantly between 17 and 50% across centers. The amount of between-center variation (tau2) was estimated at 0.040 in a model only accounting for random variation. This estimate more than doubled after adding case-mix variables (tau2: 0.086) to the model, while a small amount of between-center variation was explained by variation in performance on structure and process indicators (tau2: 0.081 and 0.089, respectively). This indicates that variation in case-mix affects the differences in outcome to a much larger extent. CONCLUSIONS: Between-center variation in outcome of ischemic stroke patients mostly reflects differences in case-mix, rather than differences in structure or process of care. Since the latter two capture the real quality improvement potential, these should be used as indicators for comparing center performance. Especially when a strong association exists between those indicators and outcome, as is the case for time to treatment in ischemic stroke.

Peripheral Artery Disease in Acute Ischemic Stroke Patients Treated With Endovascular Thrombectomy; Results From the MR CLEAN Registry.

Background and Purpose: Though peripheral artery disease (PAD) is a well-known risk factor for ischemic events, better outcomes have been described in acute ischemic stroke patients with co-existing PAD. This paradoxical association has been attributed to remote ischemic preconditioning (RIPC) and might be related to better collateral blood flow. The aim of this study is to compare outcomes after endovascular thrombectomy (EVT) in acute stroke patients with and without PAD and to assess the relation between PAD and collateral grades. Methods: We analyzed acute ischemic stroke patients treated with EVT for an anterior circulation large artery occlusion, included in the Dutch, prospective, multicenter MR CLEAN Registry between March 2014 and November 2017. Collaterals were scored on CT angiography, using a 4-point collateral score. We used logistic regression analysis to estimate the association of PAD with collateral grades and functional outcome, assessed with the modified Rankin Scale (mRS) at 90 days. Safety outcomes included mortality at 90 days, symptomatic intracranial hemorrhage, and stroke progression. Results: We included 2,765 patients for analysis, of whom 254 (9.2%) had PAD. After adjustment for potential confounders, multivariable regression analysis showed no association of PAD with functional outcome [mRS cOR 0.90 (95% CI, 0.7-1.2)], collateral grades (cOR 0.85, 95% CI 0.7-1.1), or safety outcomes. Conclusion: In the absence of an association between the presence of PAD and collateral scores or outcomes after EVT, it may be questioned whether PAD leads to RIPC in patients with acute ischemic stroke due to large vessel occlusion.

Intravenous Thrombolysis Is Not Associated with Increased Time to Endovascular Treatment.

BACKGROUND: Endovascular treatment (EVT) with or without intravenous thrombolysis (IVT) is effective and safe in is-chemic stroke caused by large vessel occlusion, but IVT might delay time to EVT or increase risk of intracranial hemorrhage (ICH). We assessed the influence of prior IVT on time to treatment and risk of ICH in patients treated with EVT. METHODS: We analyzed data from the MR CLEAN Registry and included patients with an anterior circulation occlusion treated with EVT who presented directly to an intervention center, between 2014 and 2017. Primary endpoint was the door to groin time. Secondary outcomes were workflow time intervals and safety outcomes. We compared patients who received EVT only with patients who received IVT prior to EVT. RESULTS: We included 1,427 patients directly referred to an intervention center of whom 1,023 (72%) received IVT + EVT. Adjusted door to CT imaging and door to groin time were shorter in IVT + EVT patients (difference 5.7 min [95% CI: 4.6-6.8] and 7.0 min [95% CI: 2.4-12], respectively) while CT imaging to groin time was similar between the groups. Early recanalization on digital subtraction angiography before EVT was seen more often after prior IVT (11 vs. 5.2%, aOR 2.4 [95% CI: 1.4-4.2]). Rates of symptomatic ICH were similar. CONCLUSION: Prior IVT did not delay door to groin times and was associated with higher rates of early recanalization, without increasing the risk of ICH. Our results do not warrant withholding IVT prior to EVT.

Endovascular Treatment for Acute Ischemic Stroke in Patients on Oral Anticoagulants: Results From the MR CLEAN Registry.

Background and Purpose- The use of oral anticoagulants (OAC) is considered a contra-indication for intravenous thrombolytics as acute treatment of ischemic stroke. However, little is known about the risks and benefits of endovascular treatment in patients on prior OAC. We aim to compare outcomes after endovascular treatment between patients with and without prior use of OAC. Methods- Data of patients with acute ischemic stroke caused by an intracranial anterior circulation occlusion, included in the nationwide, prospective, MR CLEAN Registry between March 2014 and November 2017, were analyzed. Outcomes of interest included symptomatic intracranial hemorrhage and functional outcome at 90 days (modified Rankin Scale score). Outcomes between groups were compared with (ordinal) logistic regression analyses, adjusted for prognostic factors. Results- Three thousand one hundred sixty-two patients were included in this study, of whom 502 (16%) used OAC. There was no significant difference in the occurrence of symptomatic intracranial hemorrhage between patients with and without prior OACs (5% versus 6%; adjusted odds ratio, 0.63 [95% CI, 0.38-1.06]). Patients on OACs had worse functional outcomes than patients without OACs (common odds ratio, 0.57 [95% CI, 0.47-0.66]). However, this observed difference in functional outcome disappeared after adjustment for prognostic factors (adjusted common odds ratio, 0.91 [95% CI, 0.74-1.13]). Conclusions- Prior OAC use in patients treated with endovascular treatment for ischemic stroke is not associated with an increased risk of symptomatic intracranial hemorrhage or worse functional outcome compared with no prior OAC use. Therefore, prior OAC use should not be a contra-indication for endovascular treatment.

Workflow Intervals of Endovascular Acute Stroke Therapy During On- Versus Off-Hours: The MR CLEAN Registry.

Background and Purpose- Endovascular treatment (EVT) of patients with acute ischemic stroke because of large vessel occlusion involves complicated logistics, which may cause a delay in treatment initiation during off-hours. This might lead to a worse functional outcome. We compared workflow intervals between endovascular treatment-treated patients presenting during off- and on-hours. Methods- We retrospectively analyzed data from the MR CLEAN Registry, a prospective, multicenter, observational study in the Netherlands and included patients with an anterior circulation large vessel occlusion who presented between March 2014 and June 2016. Off-hours were defined as presentation on Monday to Friday between 17:00 and 08:00 hours, weekends (Friday 17:00 to Monday 8:00) and national holidays. Primary end point was first door to groin time. Secondary end points were functional outcome at 90 days (modified Rankin Scale) and workflow time intervals. We stratified for transfer status, adjusted for prognostic factors, and used linear and ordinal regression models. Results- We included 1488 patients of which 936 (62.9%) presented during off-hours. Median first door to groin time was 140 minutes (95% CI, 110-182) during off-hours and 121 minutes (95% CI, 85-157) during on-hours. Adjusted first door to groin time was 14.6 minutes (95% CI, 9.3-20.0) longer during off-hours. Door to needle times for intravenous therapy were slightly longer (3.5 minutes, 95% CI, 0.7-6.3) during off-hours. Groin puncture to reperfusion times did not differ between groups. For transferred patients, the delay within the intervention center was 5.0 minutes (95% CI, 0.5-9.6) longer. There was no significant difference in functional outcome between patients presenting during off- and on-hours (adjusted odds ratio, 0.92; 95% CI, 0.74-1.14). Reperfusion rates and complication rates were similar. Conclusions- Presentation during off-hours is associated with a slight delay in start of endovascular treatment in patients with acute ischemic stroke. This treatment delay did not translate into worse functional outcome or increased complication rates.

The Effect of Body Mass Index on Outcome after Endovascular Treatment in Acute Ischemic Stroke Patients: A Post Hoc Analysis of the MR CLEAN Trial.

BACKGROUND: Though obesity is a well-known risk factor for vascular disease, the impact of obesity on stroke outcome has been disputed. Several studies have shown that obesity is associated with better functional outcome after stroke. Whether obesity influences the benefit of endovascular treatment (EVT) in stroke patients is unknown. We evaluated the association between body mass index (BMI) and outcome in acute ischemic stroke patients with large vessel -occlusion (LVO), and assessed whether BMI affects the -benefit of EVT. METHODS: This is a post hoc analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands trial (-ISRCTN10888758). BMI was used as a continuous and categorical variable, distinguishing underweight and normal weight (BMI <25), overweight (BMI 25-30), and obesity (BMI ≥30). We used multivariable ordinal logistic regression analysis to estimate the association of BMI with functional outcome (shift analysis), assessed with modified Rankin Scale (mRs) at 90 days. The impact of BMI on EVT effect was tested by the use of a multiplicative interaction term. RESULTS: Of 366 patients, 160 (44%) were underweight or normal weight, 145 (40%) overweight, and 61 (17%) were obese. In multivariable analysis with BMI as a continuous variable, we found a shift toward better functional outcome with higher BMI (mRS adjusted common OR 1.04; 95% CI 1.0-1.09), and mortality was inversely related to BMI (aOR 0.92; 95% CI 0.85-0.99). Safety analysis showed that higher BMI was associated with lower risk of stroke progression (aOR 0.92, 95% CI 0.87-0.99). Additional analysis showed no interaction between BMI and EVT effect on functional outcome, mortality, and other safety outcomes. CONCLUSION: Our study confirms the effect of obesity on outcome in acute ischemic stroke patients with LVO, meaning better functional outcome, lower mortality, and lower risk of stroke progression for patients with higher BMI. As we found no interaction between BMI and EVT effect, all BMI classes may expect the same benefit from EVT.