Vessel Occlusion Acute Ischemic Stroke Research Articles

PRESET thrombectomy device outcomes in patients with acute ischemic stroke: A systematic review and meta-analysis.

Many devices are used to perform mechanical thrombectomy in the setting of large vessel occlusion acute ischemic stroke. We sought to evaluate the efficacy and safety of pRESET stent-retriever systems. We conducted a comprehensive systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies up to March 2024 were retrieved from PubMed, Scopus, Web of Science, and Embase databases. A total of 8 papers met the inclusion/exclusion criteria comprising a total of 1140 participants (average age 72.4 ± 11.9, female percentage (50%). Preintervention intravenous thrombolysis was utilized in 46.5% (range 32.9-65.4) of patients, with a median National Institute of Health Stroke Scale at presentation of 15 (range 0-38). The middle cerebral artery was the most commonly affected artery, with a prevalence of 76.4% (range 62.8-100). The pRESET stent-retriever systems demonstrated a first-passing effect rate of 53.4% [95% confidence interval [CI] 44.8; 61.7] and a final thrombolysis in cerebral infarction 2b-3 grade rate of 90.41% [95% CI 82.13; 95.08]. Ninety-day modified Rankin Scale (0-2) rate was 42.2% [95% CI 27.6; 58.4], and 90-day mortality rate was 15.1% [95% CI 9.8; 22.6]. Postintervention hemorrhage occurred at a rate of 28.6% [CI 17.2; 43.6]. Our systematic review and meta-analysis describes the efficacy of the pRESET stent retriever system in managing acute ischemic stroke patients. The pRESET device was found to have a similar safety and efficacy profile to other mechanical thrombectomy devices currently in use.

CT perfusion to measure venous outflow in acute ischemic stroke in patients with a large vessel occlusion

BackgroundRobust venous outflow (VO) profiles, measured by degree of venous opacification on pre-thrombectomy CT angiography (CTA) studies, are strongly correlated with favorable outcomes in patients with large vessel occlusion acute...

Plasma Brain-Derived Tau in Prognosis of Large Vessel Occlusion Ischemic Stroke.

Large vessel occlusion acute ischemic stroke prognosis improved following the 2015 endovascular therapy (EVT) trials. Blood-based biomarkers may improve outcome prediction. We aimed to assess plasma brain-derived tau (BD-Tau) performance in predicting post-EVT large vessel occlusion acute ischemic stroke outcomes. We included 2 temporally independent prospective cohorts of anterior circulation in patients with large vessel occlusion acute ischemic stroke who successfully recanalized post-EVT. We measured plasma BD-Tau, GFAP (glial-fibrillary-acidic-protein), NfL (neurofilament-light-chain), and total-Tau upon admission, immediately, 24 hours, and 72 hours post-EVT. Twenty-four-hour neuroimaging and 90-day functional outcomes were independently assessed using the Alberta Stroke Program Early Computed Tomography Score (good outcome: >7 or unchanged) and the modified Rankin Scale (favorable outcome <3 or unchanged), respectively. Based on the first cohort (derivation), we built a multivariable logistic regression model to predict a 90-day functional outcome. Model results were evaluated using the second cohort (evaluation). In the derivation cohort (n=78, mean age=72.9 years, 50% women), 62% of patients had a good 24-hour neuroimaging outcome, and 45% had a favorable 90-day functional outcome. GFAP admission-to-EVT rate-of-change was the best predictor for early neuroimaging outcome but not for 90-day functional outcome. At admission, BD-Tau levels presented the highest discriminative performance for 90-day functional outcomes (area under the curve, 0.76 [95% CI, 0.65-0.87]; P<0.001). The model incorporating age, admission BD-Tau, and 24-hour Alberta Stroke Program Early Computed Tomography Score achieved excellent discrimination of 90-day functional outcome (area under the curve, 0.89 [95% CI, 0.82-0.97]; P<0.001). The score's predictive performance was maintained in the evaluation cohort (n=66; area under the curve, 0.82 [95% CI, 0.71-0.92]; P<0.001). Admission plasma BD-Tau accurately predicted 90-day functional outcomes in patients with large vessel occlusion acute ischemic stroke after successful EVT. The proposed model may predict functional outcomes using objective measures, minimizing human-related biases and serving as a simplified prognostic tool for AIS.

Sex Disparities in Mortality After Endovascular Therapy in Large Core Infarcts

Background In recent large core endovascular therapy (EVT) trials of large vessel occlusion acute ischemic stroke (AIS), treatment was associated with reduced rates of mortality. Because post‐AIS mortality can be influenced by societal and biological factors that differ between women and men, we investigate sex‐based differences in mortality outcomes following EVT in large core AIS. Methods From our prospectively collected multicenter registry across 4 comprehensive stroke centers in the Greater Houston area, we identified patients from 2017 to 2022 with large vessel occlusion AIS and large infarct core. Large infarct core was defined by computed tomography perfusion exceeding 70 mL (by regional cerebral blood flow measurements using automated postprocessing) or computed tomography Alberta Stroke Program Early CT [Computed Tomography] Score&lt;6. The primary outcome of this study was the likelihood of mortality at 90 days, determined through multivariable logistic regression adjusted for EVT, sex, and EVT/sex interaction term. Secondary outcomes included 90‐day disability outcomes and intracerebral hemorrhage. Results Among 190 patients who met inclusion criteria, 50% were female and 45.3% received EVT. Demographic differences between the sexes were largely balanced apart from the older age of presentation for women compared with men (75 versus 67, women versus men; P &lt;0.01). In univariable analysis, women who did not receive EVT had greater mortality (27.4% difference; P &lt;0.001) compared with men, with comparable rates in EVT‐treated cohorts. In multivariable analysis, non‐EVT management was strongly associated with mortality in women compared with men at discharge (odds ratio [OR] 5.81, 95% CI [1.96–17.23]) and 90‐days (OR 6.77, 95% CI [2.09–21.94]). In the secondary analysis, which additionally adjusted the model for age and National Institutes of Health Stroke Scale score, these findings were unchanged. The sex/EVT interaction term showed significant interaction for mortality both at discharge and 90 days ( P &lt;0.01). Conclusion EVT in large core AIS populations may disparately reduce mortality in women compared to men.

External validation of the iScore, ASTRAL score, DRAGON score, and THRIVE score and development of a nomogram to predict outcome in patients with large vessel occlusion-acute ischemic stroke

ObjectiveThis study aimed to validate the iScore, ASTRAL score, DRAGON score, and THRIVE score for assessing large vessel occlusion–acute ischemic stroke (AIS-LVO) and establish a predictive model for AIS-LVO patients that has better performance to guide clinical practice. MethodsWe retrospectively included 439 patients with AIS-LVO and collected baseline data from all of them. External validation of the iScore, ASTRAL score, DRAGON score, and THRIVE score was performed. All variables were compared between groups via univariate analysis, and the results are expressed as ORs and 95 % CIs. Independent variables with P < 0.25 were included in the multivariate logistic analysis, and statistically significant differences (P < 0.05) were identified as risk factors for prognosis in AIS-LVO patients. Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were used to evaluate the predictive value of our model. ResultsOur external validation resulted in an iScore under the curve (AUC) of 0.8475, an ASTRAL AUC of 0.8324, a DRAGON AUC of 0.8196, and a THRIVE AUC of 0.8039. In our research, multivariate Cox regression revealed 8 independent predictors. We used a nomogram to visualize the results of the data analysis. The AUC for the training cohort was 0.8855 (95 % CI, 0.8487-0.9222), and that in the validation cohort was 0.8992 (95 % CI, 0.8496-0. 9488). ConclusionsIn this study, we verified that the above scores have excellent efficacy in predicting the prognosis of AIS-LVO patients. The nomogram we developed was able to predict the prognosis of AIS-LVO more accurately and may contribute to personalized clinical decision-making and treatment for future clinical work.

Intracranial artery calcification: Frequency, determinants, and modification of outcomes from endovascular thrombectomy

IntroductionIntracranial artery calcification (ICAC) is a common finding on computed tomography (CT) in patients presenting with large vessel occlusion acute ischemic stroke (LVO-AIS) and could serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). MethodsThis was a retrospective cohort study analyzing consecutive patients undergoing CT head prior to EVT between 2016 and 2020. Extent of ICAC proximal to the target vessel was scored using a validated grading scale examining thickness and circumferential extent of calcifications. The relationship between 3 levels of ICAC burden and procedural, clinical, and safety outcomes was analyzed. ResultsAmong 86 patients meeting inclusion criteria, ICAC of any degree was present in 72.1 %. Median ICAC score was 3 [IQR 0-4]. There was a U-shaped association between ICAC score and successful reperfusion: 90.9 %, 65.7 %, and 94.4 % in the low, intermediate, and high ICAC score groups, respectively (p = 0.008). Use of rescue intervention, most often angioplasty and stenting, was greatest in the high ICAC score group: 3.0 % vs. 5.7 % vs. 22.2 % (p = 0.05). Functional independence at 90 days did not differ significantly among groups (41.7 % vs. 31.0 % vs. 15.4 %, p = 0.26), nor did rates of symptomatic intracranial hemorrhage (15.2 % vs. 14.3 % vs. 16.7 %, p = 0.97). ConclusionsICAC is seen on CT in nearly three-quarters of patients with LVO-AIS. Extent of ICAC has a U-shaped association with successful reperfusion, in part due to more frequent use of rescue interventions in patients with extensive ICAC.

Simplifying venous outflow: Prolonged venous transit as a novel qualitative marker correlating with acute stroke outcomes.

Prolonged venous transit (PVT), defined as presence of time-to-maximum 10 s within the superior sagittal sinus (SSS) and/or torcula, is a novel, qualitatively assessed computed tomography perfusion surrogate parameter of venous outflow with potential utility in pretreatment acute ischemic stroke imaging for neuroprognostication. We aim to characterize the correlation between PVT and neurological functional outcomes in thrombectomy-treated patients. A prospectively-collected database of large vessel occlusion acute ischemic stroke patients treated with thrombectomy was retrospectively analyzed. Spearman's rank correlation coefficient and point-biserial correlations were performed between PVT status (i.e., no region, either SSS or torcula, or both), 90-day modified Rankin score (mRS), mortality (mRS 6), and poor functional outcome (mRS 4-6 vs 0-3). Of 128 patients, correlation between PVT and 90-day mRS ( = 0.35, p < 0.0001), mortality (r = 0.26, p = 0.002), and poor functional outcome (r = 0.27, p = 0.002) were significant. There is a modest, significant correlation between PVT and severity of neurological functional outcome. Consequently, PVT is an easily-ascertained, qualitative metric that may be useful as an adjunct for anticipating a patient's clinical course. Future analyses will determine the significance of incorporating PVT in clinical decision-making.

Pre-treatment radiological factors associated with poor functional outcome in an Asian cohort of large vessel occlusion acute ischemic stroke patients undergoing mechanical thrombectomy.

Endovascular thrombectomy (EVT) is the current standard of care for large vessel occlusion (LVO) acute ischemic stroke (AIS); however, up to two-thirds of EVT patients have poor functional outcomes despite successful reperfusion. Many radiological markers have been studied as predictive biomarkers for patient outcomes in AIS. This study seeks to determine which clinico-radiological factors are associated with outcomes of interest to aid selection of patients for EVT for LVO AIS. A retrospective study of patients who underwent EVT from 2016 to 2020 was performed. Data on various radiological variables, such as anatomical parameters, clot characteristics, collateral status, and infarct size, were collected alongside traditional demographic and clinical variables. Univariate and multivariate analysis was performed for the primary outcomes of functional independence at 3 months post-stroke (modified Rankin Scale 0-2) and secondary outcomes of in-hospital mortality and symptomatic intracranial hemorrhage. The study cohort comprised 325 consecutive patients with anterior circulation LVO AIS (54.5% male) with a median age of 68 years (interquartile range 57-76). The median NIHSS was 19. Age, hypertension, hyperlipidaemia, National Institutes of Health Stroke Scale (NIHSS), Alberta mCTA score, ASPECTS, clot length, thrombus HU and mTICI score and the angle between ICA and CCA were associated with functional outcomes at 3 months on univariate analysis. On multivariate analysis, age, Alberta mCTA collaterals and NIHSS were significantly associated with functional outcomes, while ASPECTS approached significance. Among the many proposed radiological markers for patients in the hyperacute setting undergoing EVT, the existing well-validated clinico-radiological measures remain strongly associated with functional status.

Bailout intracranial angioplasty or stenting following thrombectomy for acute large vessel occlusion in China (ANGEL-REBOOT): a multicentre, open-label, blinded-endpoint, randomised controlled trial

Unsuccessful recanalisation or reocclusion after thrombectomy is associated with poor outcomes in patients with large vessel occlusion (LVO) acute ischaemic stroke (LVO-AIS). Bailout angioplasty or stenting (BAOS) could represent a promising treatment for these patients. We conducted a randomised controlled trial with the aim to investigate the safety and efficacy of BAOS following thrombectomy in patients with LVO. ANGEL-REBOOT was an investigator-initiated, multicentre, prospective, randomised, controlled, open-label, blinded-endpoint clinical trial conducted at 36 tertiary hospitals in 19 provinces in China. Participants with LVO-AIS 24 h after symptom onset were eligible if they had unsuccessful recanalisation (expanded Thrombolysis In Cerebral Infarction score of 0-2a) or risk of reocclusion (residual stenosis >70%) after thrombectomy. Eligible patients were randomly assigned by the minimisation method in a 1:1 ratio to undergo BAOS as the intervention treatment, or to receive standard therapy (continue or terminate the thrombectomy procedure) as a control group, both open-label. In both treatment groups, tirofiban could be recommended for use during and after the procedure. The primary outcome was the change in modified Rankin Scale score at 90 days, assessed in the intention-to-treat population. Safety outcomes were compared between groups. This trial was completed and registered at ClinicalTrials.gov (NCT05122286). From Dec 19, 2021, to March 17, 2023, 706 patients were screened, and 348 were enrolled, with 176 assigned to the intervention group and 172 to the control group. No patients withdrew from the trial or were lost to follow-up for the primary outcome. The median age of patients was 63 years (IQR 55-69), 258 patients (74%) were male, and 90 patients (26%) were female; all participants were Chinese. After random allocation, tirofiban was administered either intra-arterially, intravenously, or both in 334 [96%] of 348 participants. No between-group differences were observed in the primary outcome (common odds ratio 0·86 [95% CI 0·59-1·24], p=0·41). Mortality was similar between the two groups (19 [11%] of 176 vs 17 [10%] of 172), but the intervention group showed a higher risk of symptomatic intracranial haemorrhage (eight [5%] of 175 vs one [1%] of 169), parenchymal haemorrhage type 2 (six [3%] of 175 vs none in the control group), and procedure-related arterial dissection (24 [14%] of 176 vs five [3%] of 172). Among Chinese patients with unsuccessful recanalisation or who are at risk of reocclusion after thrombectomy, BAOS did not improve clinical outcome at 90 days, and incurred more complications compared with standard therapy. The off-label use of tirofiban might have affected our results and their generalisability, but our findings do not support the addition of BAOS for such patients with LVO-AIS. Beijing Natural Science Foundation, National Natural Science Foundation of China, National Key R&D Program Beijing Municipal Administration of Hospitals Incubating Program, Shanghai HeartCare Medical Technology, HeMo (China) Bioengineering, Sino Medical Sciences Technology.

Number needed to treat with intravenous tenecteplase to reduce the need for mechanical thrombectomy in large vessel occlusion acute ischemic stroke patients: A retrospective look at real-world experience data

ObjectiveWe sought to describe short term outcomes in patients with large vessel occlusion acute ischemic stroke (LVOAIS) who were treated with intravenous tenecteplase (TNK) as compared to alteplase (tPA), focusing on reduction in the need for mechanical thrombectomy (MT). BackgroundIn LVOAIS, TNK has shown improved reperfusion and outcomes with a similar safety profile to tPA. Ultra-early reperfusion has been described with TNK which would prevent the need for MT. We analyze the magnitude of this effect in a “real-world” setting. Design/MethodsIn this retrospective study, demographic, clinical, and imaging information from patients with LVOAIS treated with intravenous thrombolysis was collected. Data was compared between the group treated with TNK and tPA. ResultsOne hundred eighty-six patients met the criteria for the study. Of these,144patients received tPA and 42 received TNK. Nine had clinical improvement prior to groin puncture and did not require angiography.When combining the number of patients who had recanalization on angiography before MT and those who had clinical improvement prior to angiography, there were a total of 23 patients. This was noted in 9.7 % of patients who received tPA and 21.4 % of those who received TNK (p = 0.043). For patients treated with TNK we observed a rapid clinical improvement, improved NIHSS, improved functional outcomes and decreased length of stay compared to patients treated with tPA. For patients with spontaneous recanalization either angiographically or with clinical improvement from intravenous thrombolysis, MT may not be required. ConclusionsIntravenous TNK in patients with LVOAIS decreases the need for MT, and is associated with improved outcomes and reduced length of stay.

Hyperglycemia Is Associated With Computed Tomography Perfusion Core Volume Underestimation in Patients With Acute Ischemic Stroke With Large-Vessel Occlusion.

CT Perfusion (CTP) predictions of infarct core play an important role in the determination of treatment eligibility in large vessel occlusion (LVO) acute ischemic stroke (AIS). Prior studies have demonstrated that blood glucose can affect cerebral blood flow (CBF). Here we examine the influence of acute and chronic hyperglycemia on CTP estimations of infarct core. From our prospectively collected multi-center observational cohort, we identified patients with LVO AIS who underwent CTP with RAPID (IschemaView, Stanford, CA) post-processing, followed by endovascular therapy with substantial reperfusion (TICI 2b-3) within 90 minutes, and final infarct volume (FIV) determination by MRI 48-72 hours post-treatment. Core volume over- and under-estimations were defined as a difference of at least 20 mL between CTP-RAPID predicted infarct core and DWI FIV. Primary outcome was the association of presentation glucose and HgbA1c with underestimation (UE) of core volume and was measured using multivariable logistic regression adjusted for comorbidities and presentation characteristics. Secondary outcomes included frequency of overestimation (OE) of infarct core. Among 256 patients meeting inclusion criteria, median age was 67 [IQR 57-77], 51.6% were female, and 132 (51.6%) and 93 (36.3%) had elevated presentation glucose and elevated HgbA1c, respectively. Median CTP-predicted core was 6 mL [IQR 0-30], median DWI FIV was 14 mL [IQR 6-43] and median difference was 12 mL [IQR 5-35]. Twenty-eight (10.9%) patients had infarct core OE and 68 (26.6%) had UE. Compared to those with no UE, patients with UE had elevated blood glucose (median 119 [103-155] vs 138 [117-195], p=0.002) and HgbA1c (median 5.80 [5.40-6.40] vs 6.40 [5.50-7.90], p=0.009). In multivariable analysis, UE was independently associated with elevated glucose (aOR 2.10, p=0.038) and HgbA1c (aOR 2.37, p=0.012). OE was associated with lower presentation blood glucose (median 109 [ 99-132] in OE vs 127 [107-172] in no OE, p=0.003) and HgbA1c (5.6 [IQR 5.1 - 6.2] in OE vs 5.90 [5.50-6.70] in no OE, p=0.012). Acute and chronic hyperglycemia were strongly associated with CTP UE in patients with LVO AIS undergoing EVT. Glycemic state should be considered when interpreting CTP findings in patients with LVO AIS.

Machine Learning–Enabled Automated Large Vessel Occlusion Detection Improves Transfer Times at Primary Stroke Centers

Background Accelerating door‐in‐door‐out (DIDO) times at primary stroke centers (PSCs) for patients with large vessel occlusion (LVO) acute ischemic stroke transferred for possible endovascular stroke therapy (EVT) is important to optimize outcomes. Here, we assess whether automated LVO detection coupled with secure communication at non‐EVT performing PSCs improves DIDO time and increases the proportion of patients receiving EVT after transfer. Methods From our prospectively collected multicenter registry, we identified patients with LVO acute ischemic stroke that presented to one of 7 PSCs in the Greater Houston area from January 1, 2021, to February 27, 2022. Noncontrast computed tomography and computed tomographic angiography were performed in all patients at the time of presentation, per standard of care. A machine learning (artificial intelligence [AI]) algorithm trained to detect LVO (Viz.AI) from computed tomographic angiography was implemented at all 7 hospitals. The primary outcome of the study was DIDO at the PSCs and was determined using multivariable linear regression adjusted for sex and on/off hours. Secondary outcomes included likelihood of receiving EVT post‐transfer. Results Among 115 patients who met inclusion criteria, 80 were evaluated pre‐AI and 35 post‐AI. The most common occlusion locations were middle cerebral artery (51.3%) and internal carotid artery (25.2%). There were no substantial differences in demographics or presentation characteristics between the 2 groups. Median time from onset to PSC arrival was 117 minutes (interquartile range, 54–521 minutes). In univariable analysis, patients evaluated at the PSCs after AI implementation had a shorter DIDO time (median difference, 77 minutes; P &lt;0.001). In multivariable linear regression, patients evaluated with automated LVO detection AI software were associated with a 106‐minute (95% CI, −165 to −48 minutes) reduction in DIDO time but no difference in likelihood of EVT post‐transfer (odd ratio, 2.13 [95% CI, 0.88–5.13). Conclusion Implementation of a machine learning method for automated LVO detection coupled with secure communication resulted in a substantial decrease in DIDO time at non‐EVT performing PSCs.

Impact of Procedure Time on First Pass Effect in Mechanical Thrombectomy for Anterior Circulation Acute Ischemic Stroke.

First pass effect (FPE) is a metric increasingly used to determine the success of mechanical thrombectomy (MT) procedures. However, few studies have investigated whether the duration of the procedure can modify the clinical benefit of FPE. We sought to determine whether FPE after MT for anterior circulation large vessel occlusion acute ischemic stroke is modified by procedural time (PT). A multicenter, international data set was retrospectively analyzed for anterior circulation large vessel occlusion acute ischemic stroke treated by MT who achieved excellent reperfusion (thrombolysis in cerebral infarction 2c/3). The primary outcome was good functional outcome defined by 90-day modified Rankin scale scores of 0-2. The primary study exposure was first pass success (FPS, 1 pass vs ≥2 passes) and the secondary exposure was PT. We fit-adjusted logistic regression models and used marginal effects to assess the interaction between PT (≤30 vs >30 minutes) and FPS, adjusting for potential confounders including time from stroke presentation. A total of 1310 patients had excellent reperfusion. These patients were divided into 2 cohorts based on PT: ≤30 minutes (777 patients, 59.3%) and >30 minutes (533 patients, 40.7%). Good functional outcome was observed in 658 patients (50.2%). The interaction term between FPS and PT was significant ( P = .018). Individuals with FPS in ≤30 minutes had 11.5% higher adjusted predicted probability of good outcome compared with those who required ≥2 passes (58.2% vs 46.7%, P = .001). However, there was no significant difference in the adjusted predicted probability of good outcome in individuals with PT >30 minutes. This relationship appeared identical in models with PT treated as a continuous variable. FPE is modified by PT, with the added clinical benefit lost in longer procedures greater than 30 minutes. A comprehensive metric for MT procedures, namely, FPE 30 , may better represent the ideal of fast, complete reperfusion with a single pass of a thrombectomy device.

Anesthetic management for large vessel occlusion acute ischemic stroke with tandem lesions

BackgroundEndovascular therapy (EVT) stands as an established and effective intervention for acute ischemic stroke in patients harboring tandem lesions (TLs). However, the optimal anesthetic strategy for EVT in TL patients...

Late Lesion Growth following Endovascular Therapy: Is 24 h Too Early to Assess Acute Infarct Size Including the Effects of Secondary Injury?

Introduction: Stroke lesion volume on MRI or CT provides objective evidence of tissue injury as a consequence of ischemic stroke. Measurement of “final” lesion volume at 24-h following endovascular therapy (post-EVT) has been used in multiple studies as a surrogate for clinical outcome. However, despite successful recanalization, a significant proportion of patients do not experience favorable clinical outcome. The goals of this study were to quantify lesion growth during the first week after treatment, identify early predictors, and explore the association with clinical outcome. Methods: This is a prospective study of stroke patients at two centers who met the following criteria: (i) anterior large vessel occlusion acute ischemic stroke, (ii) attempted EVT, and (iii) had 3T MRI post-EVT at 24-h and 5-day. We defined “early” and “late” lesion growth as ≥10 mL lesion growth between baseline and 24-h diffusion-weighted imaging (DWI) and between 24-h DWI and 5-day fluid attenuated inversion recovery imaging, respectively. Complete reperfusion was defined as >90% reduction of the volume of tissue with perfusion delay (Tmax>6 s) between pre-EVT and 24-h post-EVT. Favorable clinical outcome was defined as modified Rankin scale (mRS) of 0–2 at 30 or 90 days. Results: One hundred twelve patients met study criteria with median age 67 years, 56% female, median admit NIHSS 19, 54% received IV or IA thrombolysis, 66% with M1 occlusion, and median baseline DWI volume 21.2 mL. Successful recanalization was achieved in 87%, and 68% had complete reperfusion, with an overall favorable clinical outcome rate of 53%. Nearly two-thirds (65%) of the patients did not have late lesion growth with a median volume change of −0.3 mL between 24-h and 5-day and an associated high rate of favorable clinical outcome (64%). However, ∼1/3 of patients (35%) did have significant late lesion growth despite successful recanalization (87%: 46% mTICI 2b/41% mTICI 3). Late lesion growth patients had a 27.4 mL change in late lesion volume and 30.1 mL change in early lesion volume. These patients had an increased hemorrhagic transformation (HT) rate of 68% with only 1 in 3 patients having favorable clinical outcome. Late lesion growth was independently associated with incomplete reperfusion, HT, and unfavorable outcome. Conclusion: Approximately 1 out of 3 patients had late lesion growth following EVT, with a favorable clinical outcome occurring in only 1 out of 3 of these patients. Most patients with no early lesion growth had no late lesion growth. Identification of patients with late lesion growth could be critical to guide clinical management and inform prognosis post-EVT. Additionally, it can serve as an imaging biomarker for the development of adjunctive therapies to mitigate reperfusion injury.

Deep medullary vein damage correlates with small vessel disease in small vessel occlusion acute ischemic stroke

ObjectivesWe aim to investigate whether cerebral small vessel disease (cSVD) imaging markers correlate with deep medullary vein (DMV) damage in small vessel occlusion acute ischemic stroke (SVO-AIS) patients.MethodsThe DMV was divided into six segments according to the regional anatomy. The total DMV score (0–18) was calculated based on segmental continuity and visibility. The damage of DMV was grouped according to the quartiles of the total DMV score. Neuroimaging biomarkers of cSVD including white matter hyperintensity (WMH), cerebral microbleed (CMB), perivascular space (PVS), and lacune were identified. The cSVD score were further analyzed.ResultsWe included 229 SVO-AIS patients, the mean age was 63.7 ± 23.1 years, the median NIHSS score was 3 (IQR, 2–6). In the severe DMV burden group (the 4th quartile), the NIHSS score grade (6 (3–9)) was significantly higher than other groups (p < 0.01). The grade scores for basal ganglia PVS (BG-PVS) were positively correlated with the degree of DMV (R = 0.67, p < 0.01), rather than centrum semivole PVS (CS-PVS) (R = 0.17, p = 0.1). In multivariate analysis, high CMB burden (adjusted odds ratio [aOR], 25.38; 95% confidence interval [CI], 1.87–345.23) was associated with severe DMV scores. In addition, BG-PVS was related to severe DMV burden in a dose-dependent manner: when BG-PVS score was 3 and 4, the aORs of severe DMV burden were 18.5 and 12.19, respectively.ConclusionThe DMV impairment was associated with the severity of cSVD, which suggests that DMV burden may be used for risk stratification in SVO-AIS patients.Clinical relevance statementThe DMV damage score, based on the association between small vessel disease and the deep medullary veins impairment, is a potential new imaging biomarker for the prognosis of small vessel occlusion acute ischemic stroke, with clinical management implications.Key Points• The damage to the deep medullary vein may be one mechanism of cerebral small vessel disease.• Severe burden of the basal ganglia perivascular space and cerebral microbleed is closely associated with significant impairment to the deep medullary vein.• The deep medullary vein damage score may reflect a risk of added vascular damage in small vessel occlusion acute ischemic stroke patients.

Abstract 153: First Pass Effect in Mechanical Thrombectomy for Anterior Circulation Acute Ischemic Stroke is Modified by Procedure Time: Proposal of a New Measure for Thrombectomy Procedures

Objective: To determine whether first pass effect (FPE) after mechanical thrombectomy (MT) for anterior circulation large vessel occlusion acute ischemic stroke (LVO-AIS) is modified by procedural time (PT). Methods: The Stroke Thrombectomy and Aneurysm Registry (STAR), a multi-center international dataset, was retrospectively analyzed for anterior circulation LVO-AIS treated by MT who achieved excellent reperfusion (TICI 2c/3). The primary outcome was good functional outcome as defined by a 90-day modified Rankin Scale (mRS) 0-2. The primary study exposure was first pass success (FPS, 1 pass vs ≥2 passes) and the secondary exposure was PT. Logistic regression models were fit-adjusted and marginal effects used to assess the interaction of PT (≤30 vs &gt;30 minutes) and FPS, adjusting for potential confounders including time from last known well to start of MT. Results: A total of 1,310 patients had excellent reperfusion. These patients were divided into two cohorts based on PT: ≤30 minutes (777 patients, 59.3%) and &gt; 30 minutes (533 patients, 40.7%). Good functional outcome was observed in 658 patients (50.2%). The interaction term between FPS and PT was significant (p=0.018). Individuals with FPS in ≤30 minutes had 11.5% higher adjusted predicted probability of good outcome compared with those who required ≥2 passes (58.2% vs. 46.7%, p=0.001). However, there was no significant difference in the adjusted predicted probability of good outcome based on FPS in individuals with PT &gt;30 minutes (p=0.763). This relationship appeared identical in models with PT treated as a continuous variable. Conclusion: In a large, real-world, multi-national dataset, we find that FPE is importantly modified by PT. The added clinical benefit of FPE is lost in longer procedures (&gt;30 minutes). These data argue for a new metric for MT procedures, namely, FPE 30 , that better represents the ideal of fast, complete reperfusion with a single pass of a thrombectomy device.

Abstract TP183: Endovascular Thrombectomy in Patients With Pre-Existing Disability Presenting With Large Vessel Occlusion Stroke

Introduction: Despite representing a substantial proportion of patients who present with large vessel occlusion (LVO) acute ischemic stroke (AIS), patients with baseline disability are often excluded from endovascular thrombectomy (EVT) clinical trials. We present our institutional experience with EVT in this patient population. Methods: Prospectively maintained database from our comprehensive stroke center was retrospectively reviewed for consecutive cases from December 2014 to July 2023. Patients who underwent EVT were included. Two groups of patients were created; patients without existing disability (modified Rankin Score [mRS] 0-1) and those with existing disability (mRS≥2). Demographics and comorbidities were compared. Difference in 90 day mRS and baseline mRS (delta mRS) was calculated as primary outcome measure. Wilcoxon rank test and generalized linear regression were used for analysis. Results: Total of 1441 patients were identified, 347 patients (24.1%) had pre-existing disability.This group had higher average age (82 vs 68, p&lt;0.01), a higher proportion of female patients (66.57% vs 41.13%, p&lt;0.001), and elevated rates of comorbidities such as atrial fibrillation, diabetes, and hypertension. Additionally, they presented with a slightly higher median NIHSS of 18 (vs 15, p&lt;0.001).There was no difference in the rate of successful reperfusion (TICI 2b-3:90.49% vs 87.53%, p=0.16), or symptomatic ICH (1.44% vs 1.83%, p=0.75) between the two groups. Higher rate of delta mRS=0 (return to baseline) was observed in patients with pre-existing disability (17.58% vs 8.98%, p&lt;0.001). Similarly, delta mRS ≤ 1 was higher in this group (33.43% vs 22.36%, p&lt;0.001). In multivariable analysis, after adjusting for initial stroke severity and ASPECTS, patients with pre-existing disabilities had higher rate of return to baseline functional status and similar rate of ICH. Pre-existing deficit predicted an increase in delta mRS ≤ 1 (β=1.04, p&lt;0.001). Conclusion: EVT appears to be safe and effective in patients with baseline disability, often returning patients to their pre-morbid functional status by 90 days follow up. Although further studies are needed, it is reasonable to offer EVT for patients with baseline disability presenting with LVO stroke.

Abstract WMP64: Late Lesion Growth Following Endovascular Therapy: Is 24 Hours Too Early to Assess Acute Infarct Size Including the Effects of Secondary Injury?

Background: Measurement of “final” lesion volume at 24hr following endovascular therapy (post-EVT) has been used in multiple studies as a surrogate for clinical outcome. However, despite successful recanalization, a significant proportion of patients do not experience favorable clinical outcome. Methods: This is a prospective study of acute ischemic stroke patients at two stroke centers who met the following criteria: i) anterior large vessel occlusion (LVO) acute ischemic stroke, ii) attempted EVT, iii) written informed consent obtained, and iv) had MRI post-EVT at 24hr and 5-day. We defined “Early” and “Late” lesion growth as ≥10mL lesion growth between baseline and 24hr DWI, and between 24hr DWI and 5-day FLAIR, respectively. Results: One hundred fourteen patients met study criteria with median age 67 years, 56% female, median admit NIHSS 19, 54% received IV or IA thrombolysis, 67% with M1 occlusion, and median baseline DWI volume 28.2mL. Successful recanalization was achieved in 86% and 67% had complete reperfusion, with an overall favorable clinical outcome rate of 54%. Nearly two thirds (65%) of the patients did not have Late lesion growth with a median volume change of -0.2mL between 24hr and 5-days and an associated high rate of favorable clinical outcome (65%). However, ~1/3 of patients (35%) did have significant Late lesion growth despite successful recanalization (85% TICI 2b/3). Late lesion growth patients had a 26.2mL change in Late lesion volume and 19.9mL change in Early lesion volume. These patients had an increased hemorrhagic transformation rate of 68% with only 1 in 3 patients having favorable clinical outcome. Late lesion growth was independently associated with incomplete reperfusion, hemorrhagic transformation, and unfavorable outcome even after adjusting for admit NIHSS and Early lesion growth. Conclusions: Approximately 1 out of 3 patients had Late lesion growth following EVT, with a favorable clinical outcome occurring in only 1 out of 3 of these patients. Identification of patients with Late lesion growth could be critical to guide clinical management and inform prognosis post-EVT. Additionally it can serve as an imaging biomarker for the development of adjunctive therapies to mitigate reperfusion injury.

Development and Validation of a Prediction Model for Failure of the Transfemoral Approach of Endovascular Treatment for Large Vessel Occlusion Acute Ischemic Stroke

Introduction: Extracranial vascular characteristics determine the accessibility of the large vessel intracranial occlusion for endovascular treatment (EVT) in acute ischemic stroke. We developed and validated a prediction model for failure of the transfemoral approach to aid clinical decision-making regarding EVT. Methods: A prediction model was developed from data of patients included in the Dutch multicenter MR CLEAN Registry (March 18, 2014, until June 15, 2016) with penalized logistic regression. Predictor variables were available prior to the EVT procedure and included age, hypertension, and extracranial vascular characteristics assessed on baseline CTA. The prediction model was internally validated, temporally validated within a second MR CLEAN Registry cohort (June 15, 2016, until November 1, 2017), and updated by re-estimating the coefficients using the combined cohort. Results: Failure of the transfemoral approach occurred in 7% of patients, in both cohorts (derivation cohort: n = 887, median age 71 years, interquartile range [IQR] 60–80, 52% men; validation cohort: n = 1,111, median age 73 years, IQR: 62–81, 51% men). The prediction model had a c-statistic of 0.81 (95% CI: 0.76–0.86) in the derivation cohort, 0.69 (95% CI: 0.62–0.75) at temporal validation, and 0.75 (95% CI: 0.71–0.79) in the final prediction model, with the following penalized β-coefficients for predictor age (per decade): 0.26, hypertension: −0.16, severe aortic arch elongation: 1.45, bovine aortic arch: 0.44, elongation of the supra-aortic arteries: 0.72, cervical ICA elongation: 0.44, and high-grade stenosis of the cervical ICA: 0.78. Conclusion: Our prediction model showed good performance for prediction of failure to reach the intracranial occlusion by the transfemoral approach.