Infarct Core Research Articles

Alberta Stroke Program Early Computed Tomography Score, Infarct Core Volume, and Endovascular Therapy Outcomes in Patients With Large Infarct

Endovascular therapy (EVT) demonstrated better outcomes compared with medical management in recent randomized clinical trials (RCTs) of patients with large infarct. To compare outcomes of EVT vs medical management across different strata of the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and infarct core volume in patients with large infarct. This prespecified secondary analysis of subgroups of the Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients With a Large Infarct Core (ANGEL-ASPECT) RCT included patients from 46 stroke centers across China between October 2, 2020, and May 18, 2022. Participants were enrolled within 24 hours of symptom onset and had ASPECTS of 3 to 5 or 0 to 2 and infarct core volume of 70 to 100 mL. Patients were divided into 3 groups: ASPECTS of 3 to 5 with infarct core volume less than 70 mL, ASPECTS of 3 to 5 with infarct core volume of 70 mL or greater, and ASPECTS of 0 to 2. Endovascular therapy or medical management. The primary outcome was the ordinal 90-day modified Rankin Scale (mRS) score. There were 455 patients in the trial; median age was 68 years (IQR, 60-73 years), and 279 (61.3%) were male. The treatment effect did not vary significantly across the 3 baseline imaging subgroups (P = .95 for interaction). The generalized odds ratio for the shift in the 90-day mRS distribution toward better outcomes with EVT vs medical management was 1.40 (95% CI, 1.06-1.85; P = .01) in patients with ASPECTS of 3 to 5 and infarct core volume less than 70 mL, 1.22 (95% CI, 0.81-1.83; P = .23) in patients with ASPECTS of 3 to 5 and infarct core volume of 70 mL or greater, and 1.59 (95% CI, 0.89-2.86; P = .09) in patients with ASPECTS of 0 to 2. In this study, no significant interaction was found between baseline imaging status and the benefit of EVT compared with medical management in patients with large infarct core volume. However, estimates within subgroups were underpowered. A pooled analysis of large core trials stratified by ASPECTS and infarct core volume strata is warranted. ClinicalTrials.gov Identifier: NCT04551664.

Outcomes of mechanical thrombectomy in stroke patients with extreme large infarction core

BackgroundRecent clinical trials have demonstrated that patients with large vessel occlusion (LVO) and large infarction core may still benefit from mechanical thrombectomy (MT). In this study, we evaluate outcomes of...

Nomogram Based on Dual-Layer Spectral Detector CTA Parameter for the Prediction of Infarct Core in Patients with Acute Ischemic Stroke.

(1) Background: Acute ischemic stroke (AIS) is time-sensitive. The accurate identification of the infarct core and penumbra areas in AIS patients is an important basis for formulating treatment plans, and is the key to dual-layer spectral detector computed tomography angiography (DLCTA), a safer and more accurate diagnostic method for AIS that will replace computed tomography perfusion (CTP) in the future. Thus, this study aimed to investigate the value of DLCTA in differentiating infarct core from penumbra in patients with AIS to establish a nomogram combined with spectral computed tomography (CT) parameters for predicting the infarct core and performing multi-angle evaluation. (2) Methods: Data for 102 patients with AIS were retrospectively collected. All patients underwent DLCTA and CTP. The patients were divided into the non-infarct core group and the infarct core group, using CTP as the reference. Multivariate logistic regression analysis was used to screen predictors related to the infarct core and establish a nomogram model. The receiver operating characteristic (ROC) curve, the calibration curve, and decision curve analysis (DCA) were used to evaluate the predictive efficacy, accuracy, and clinical practicability of the model, respectively. (3) Results: Multivariate logistic analysis identified three independent predictors: iodine density (OR: 0.022, 95% CI: 0.003-0.170, p < 0.001), hypertension (OR: 7.179, 95% CI: 1.766-29.186, p = 0.006), and triglycerides (OR: 0.255, 95% CI: 0.109-0.594, p = 0.002). The AUC-ROC of the nomogram was 0.913. Calibration was good. Decision curve analysis was clinically useful. (4) Conclusions: The spectral CT parameters, specifically iodine density values, effectively differentiate between the infarct core and penumbra areas in patients with AIS. The nomogram, based on iodine density values, showed strong predictive power, discrimination, and clinical utility to accurately predict infarct core in AIS patients.

Spatiotemporal expression patterns of ZBP1 in the brain of mouse experimental stroke model

Z-DNA binding protein 1 (ZBP1) is a cytosolic nucleic acid sensor, functioning as a critical mediator of inflammation and cell death pathways. Since neuroinflammation could occur in response to damage-associated molecular patterns (DAMPs), ZBP1 might be involved in neuroinflammation after stroke. However, the spatiotemporal expression profile of ZBP1 in the post-stroke brain remains to be elucidated. The aim of this study is to demonstrate the spatiotemporal expression patterns of ZBP1 in the post-stroke brain using a mouse photothrombotic stroke model. Real-time PCR assays showed that ZBP1 is induced on days 3–14 post stroke. ZBP1 immunoreactivity was observed in Iba1-positive microglia/macrophages in peri-infarct regions by immunohistochemistry. ZBP1-positive cells were spread in layers surrounding the infarct core by 7–14 days post stroke. Interestingly, ZBP1 immunoreactivity was also detected in CD206-positive border-associated macrophages (BAMs) in the meninges. Furthermore, ZBP1-expressing cells were positive for antibodies against inflammatory mediators such as Toll-like receptor 4 (TLR4), Toll/IL-1R domain-containing adaptor-inducing IFN-β (TRIF), and receptor-interacting serine/threonine-protein kinase 1 (RIPK1). Morphological analysis with confocal microscopy showed that the co-localization signals of ZBP1 and its adaptor, TRIF, are increased by glucose oxidase (GOx) treatment, which has been reported to induce mitochondrial DNA (mtDNA) release. These results suggest that ZBP1 is induced in peri-infarct microglia/macrophages and may be involved in DAMPs-mediated neuroinflammation involving mtDNA in the post-infarct brain.

Association of dysglycaemia with persistent infarct core iron in patients with acute ST-segment elevation myocardial infarction

Abstract Background Dysglycaemia increases the risk of myocardial infarction and subsequent recurrent cardiovascular events. However, the role of dysglycaemia in ischemia/reperfusion injury with development of irreversible myocardial tissue alterations remains poorly understood. Objectives To investigate the association of dysglycaemia with persistence of infarct core iron and their longitudinal changes over time in patients undergoing primary percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI). Methods We analyzed 348 STEMI patients treated with primary PCI between 2016 and 2021 that were included in a prospective observational study. Peripheral venous blood samples for glucose and glycated hemoglobin (HbA1c) measurements were drawn on admission and 4 months after STEMI. Cardiac magnetic resonance (CMR) imaging including T2* mapping for infarct core iron assessment was performed at both time points. Associations of dysglycaemia with persistent infarct core iron and iron resolution at 4 months were calculated using multivariable regression analysis. Results Persistent infarct core iron was present in 89 (26%) patients (HBA1c &amp;lt;5.7%: 16%, 5.7-6.4: 37%, ≥6.5: 34%) and was independently associated with HbA1c levels (OR: 1.64 [95% CI: 1.11-2.42]; p=0.01), but not glucose levels on admission. The independent association was present even after exclusion of patients with diabetes (pre- and newly diagnosed, n=42). Infarct core iron resolution was observed in 34 (14%) patients and was independently associated with HbA1c levels at 4 months (OR: 0.51 [95% CI: 0.28-0.93]; p=0.03). Conclusions In STEMI patients treated with primary PCI, dysglycaemia is independently associated with persistent infarct core iron and impaired iron resolution at 4 months. Persistent infarct core iron might represent a mechanistic driver for adverse outcome and a potential therapeutic target in patients with altered glycemic status suffering acute STEMI.

Abstract 17854: Imaging Intravascular Macrophages Using Micro-Sized Superparamagnetic Decoys

Introduction: During inflammatory processes, intravascular macrophages are capable of phagocytizing circulating debris in the circulation. Hypothesis: Intravenous injection of contrast-loaded decoys could be used to label intravascular macrophages and map their distribution by non-invasive imaging. Methods: We synthetized superparamagnetic decoys with hydrodynamic diameters from 20 nm to 4.5 μm. Experimental models of neuroinflammation (intrastriatal injection of LPS or TNF) and ischemic stroke (thrombin model and ferric chloride model) were performed in mice. High resolution 3D T2*-weighted MRI sequences were performed after intravenous injection of the superparamagnetic decoys. Results: In experimental models of neuroinflammation, intravenous injection of superparamagnetic decoys with a diameter of 1 μm (but neither smaller nor larger particles) reveals intravascular phagocytic cells in the cerebral circulation, in a dose dependent manner. In ischemic stroke, we found that intravenous injection of the decoys leads to numerous signal voids in the vessels in and around the infarct core at 48 hours (Figure 1a-b). Interestingly, the intravascular phagocytic activity appears much higher in permanent rather than transient models of ischemic stroke. Pre-treatment with anti-CD11a blocking antibodies significantly reduced the number of intravascular macrophages in stroke. Histological studies confirmed that injected decoys are phagocytized by intravascular cells which express typical markers of the monocyte/macrophage lineage including CX3CR1 dependent GFP expression and CD68 (Figure 1c). Conclusions: Intravenous injection of superparamagnetic decoys in the micrometer size range allows to image intravascular macrophages. This new method allows to study the pathophysiological roles of intravascular macrophages in experimental models and could be easily translated to humans.

Endovascular therapy for acute stroke with a large infarct core: A systematic review and meta-analysis

ObjectiveIn this meta-analysis, we aimed to investigate the efficacy and safety of endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with large core infarct. MethodsThree online databases of Web of Science, PubMed and Scopus were systematically searched. Original studies which evaluated AIS participants with large core infarction who underwent EVT were included. R statistical software was used for statistical analyses. Effect sizes were presented with odds ratios (ORs) with their 95% confidence intervals (CIs). The effect sizes were pooled using random effects modeling. ResultsIncluding 47 studies and 15,173 patients, this meta-analysis showed that compared with medical management (MM), EVT was significantly associated with decreased odds of mortality (0.67, 95% CI: 0.51–0.87) and increased odds of favorable outcomes, including a modified Rankin Scale of 0–3 (2.36, 95% CI: 1.69–3.291) and of 0–2 (3.54, 95% CI: 1.96–6.4) in 90 days and remarkable improvement in National Institutes of Health Stroke Scale within 48 h after the procedure (3.6, 95% CI:1.32–9.79). Besides, there was a higher chance of intracranial hemorrhage (ICH) development (1.88, 95% CI: 1.32–2.68) but not symptomatic ICH (1.34, 95% CI: 0.78–2.31) in those who underwent EVT. ConclusionOur study suggests that EVT might be an effective and relatively safe treatment option for the treatment of AIS patients with large vessel occlusion who have large core infarcts, although more large-scale trials are needed to consolidate the results and to make inclusion criteria and the patient selection process clearer.

Blood Pressure Variability Is Associated with Infarct Growth in Acute Ischaemic Stroke

Introduction: Evidence-based blood pressure (BP) targets in acute ischaemic stroke are lacking. Previous observational studies have focused on single baseline BP and clinical outcomes, without consideration for dynamic changes. We aim to determine the association between BP parameters including variability, peak, nadir, median and mean during stroke and infarct growth (primary outcome), risk of haemorrhagic transformation, and functional outcome (secondary outcomes). Methods: Suspected stroke patients were prospectively recruited from a single comprehensive stroke centre. Multimodal computed tomography imaging was used to define infarct core. BP was recorded as per national stroke guidelines during the initial 24 h. Infarct growth and evidence of parenchymal haemorrhage were determined by follow-up magnetic resonance imaging at 24 h. Functional outcome at 3 months was assessed using the modified Rankin Scale. Subgroup analysis was performed according to stroke aetiology and treatment for the association between BP, infarct volume growth, and risk of haemorrhagic transformation. The association between BP parameters and outcomes were determined using regression modelling. Results: A total of 229 patients were included in this study. The median age was 67.4, 64.4% were male, and the baseline National Institutes of Health Stroke Scale was 8. BP variability (BPV) was independently associated with increased infarct growth (multivariate coefficient 1.60, 95% CI: 0.27–2.94, p = 0.19) and an increased odds of parenchymal haemorrhage (adjusted OR 1.21, 95% CI: 1.02–1.44, p = 0.028). The odds of a favourable outcome at 90 days were inversely associated with BPV on simple, but not adjusted logistic regression. On subgroup analysis, only in patients with large vessel occlusions, undergoing endovascular clot retrieval, was BPV associated with infarct growth (multivariate-adjusted coefficient 2.62, 95% CI: 0.53–4.70, p = 0.014) and an increased odds of haemorrhagic transformation (adjusted OR 1.26, 95% CI: 1.01–1.57, p = 0.045). Conclusion: An increase in BPV was associated with infarct expansion, increased risk of haemorrhagic transformation and was negatively associated with favourable functional outcomes at 3 months.

Abstract 062: N20 Potential And Imaging Biomarkers Of Functional Recovery In Acute Ischemic Stroke Patients And EVT

Introduction PROMISE trial has shown high predictive accuracy of the N20 somatosensory evoked potential (SEP) response on functional recovery in patients with AIS undergoing endovascular thrombectomy (EVT). This secondary study aims to describe the association between the N20 response and imaging biomarkers of ischemic penumbra, infarct volume and collateral flow. Methods Presence and amplitude of the N20 response was recorded before EVT. At baseline, infarct core was automatically calculated establishing a threshold value of ADC&lt;620x10‐6mm2/s in MR and of rCBF&lt;30% in CTP; ischemic volume was estimated as Tmax &gt;6 sec; and hypoperfusion intensity ratio (HIR) as the proportion of ischemic volume that also has a delay in Tmax&gt;10s. Leptomeningeal collaterals were classified according to the Arterial Collateral Grading Scale in CTA as "poor" (absence and &lt;50%) and optimal (&gt;50%, equal to and greater than the contralateral), or according to the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale when the acquired image was dynamic MR angiography, dichotomized as incomplete collateral fill (poor collateral) (grades 0 to 2) and complete collateral fill (optimal collateral) (grades 3 and 4). Collaterals were not evaluated in the conventional angiography since we did not perform a full study to shorten the time to thrombus access. The adjusted predictive value of N20 for functional recovery was analyzed by logistic regression and compared with imaging variables by using receiver operating characteristic curves. Results From 223 patients studied, 99 patients had multimodal imaging with perfusion studies and N20 assessable recordings at baseline (mean age, 70y; median NIHSS, 18), 63 patients with present (N20+) and 36 with absent N20 response (N20‐). Median infarct core was 12 (0‐25) and 16 (3‐60) cc (p= 0,193), ischemic volume 81 (39‐132) and 111 (54‐188) cc (p=0,082) and the HIR 0,4 (0,2‐0,6) 0,4 (0,3‐0,6) (p=0,572), respectively. N20+ was associated to a better collateral flow (OR 2,5; [1,2‐5,3]; p=0,01). N20+ showed the highest predictive capacity of functional recovery at day 7 compared to imaging variables (Table 1) and increased 15 (4‐103) fold the likelihood of good outcome after adjusting for collateral flow 2.94 (1.10‐8.40), ASPECT score (1,17 (0,74 ‐ 1,87) and infarct core 0.98 (0.95‐1.01). Conclusion N20 SEP response is a powerful biomarker of functional recovery that might surrogate advanced imaging in patients with AIS evaluated for endovascular thrombectomy.

Key CT markers for predicting haemorrhagic transformation after ischaemic stroke: a prospective cohort study in China

ObjectivesLimited studies have systematically addressed the CT markers of predicting haemorrhagic transformation (HT). We aimed to (1) investigate the predictive ability of the imaging factors on multimodal CT for HT...

Abstract 247: Visual versus Computer Software Assessment of Perfusion in Anterior Circulation Stroke Treated with Mechanical Thrombectomy

Introduction In the absence of an automated software analysis, the role of computed tomography perfusion (CTP) in a real time clinical practice is not well established. In a pilot study on 318 acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT), we established that visual, semi quantitative evaluation of CTP strongly correlates with clinical outcome, independently of collateral circulation status and ASPECT score. The visual CTP assessment was based only on TTP (time to peak) perfusion maps that are widely accessible, simple to perform on any CT scanner and easy to analyze even by a non‐specialized radiologist. To expand on these results, we are currently performing a direct comparison of the visual and computer‐based CTP assessment and their independent prediction of clinical outcome in AIS patients treated with MT in anterior circulation. Methods The single center consecutive CT investigations of AIS patients treated with MT in the anterior circulation were evaluated retrospectively. ASPECT score and collateral circulation evaluation based on the Maas score were determined. CTP assessments, performed either by the visual or computer based method, were graded into four categories, from least to most favorable. Visual grading was based on the percentage of »black regions« on TTP parametric maps, which represent a complete fallout of signal and presumably correlate with infarction core, in comparison to the whole area of the hypo‐perfused territory. Computer based CTP assessment was performed by syngo® Neuro Perfusion CT software. Ischemic core was defined as an area with reduced relative cerebral blood flow (rCBF) below 30% and the hypo‐perfused territory as an area with time to maximum (Tmax) residue function exceeding 6 seconds. The relative volumes of the core were transformed into percentages and graded accordingly. The primary endpoint was excellent functional outcome defined as modified Rankin Scale (mRS) ≤2 at 90 days after MT. Results In the pilot study, we included 318 patients, with 142 (45%) having mRS≤ 2 after 90 days, and the mortality rate was 24%. The visually determined CTP grade demonstrated statistically significant independent correlation with the clinical outcome, irrespective of the collateral circulation, ASPECT score and age (OR 2.5; p= 0.011). As an extension of the pilot study, we are undergoing analysis of 1029 patients that underwent MT from 2013 until the end of 2022. The preliminary findings point towards a good correlation between the visual and computer based CTP assessment. Conclusion The preliminary results of the ongoing direct comparison of the visual and computer based CTP assessment point towards a good correlation with concordant predictability of clinical outcome of both methods. The results of this study provide an additional scientific background for using the visual semi‐quantitative CTP evaluation in clinical practice for patients who are candidates for MT. As this method is simple and easy to use, it can be performed in almost any CT unit, even without a software program for CTP analysis or advanced subspecialized knowledge in neuroradiology.

Abstract 230: Endovascular therapy for large core ischemic strokes: Meta‐analysis of randomized clinical trials

Introduction Background: Patients with acute strokes with large infarct size are traditionally excluded from endovascular therapies, as like as clinical care. However, questions remain with respect to the safety and efficacy of EVT in these patients. Methods We conducted a meta‐analysis based on pooled data from SELECT 2 trial [1], ANGEL‐ASPECT trial [2], RESCUE Japan [3], and HERMES study [4]. We explored the efficacy of EVT for large infarcts to achieve a favorable 90‐day modified Rankin Scale. Also, we compared favorable outcomes following EVT in those with a core infarct at baseline of more than 70 ml, delayed thrombectomy of more than 6 hours, older than 75 years, and those who received concomitant IV thrombolysis. We also examined the pooled rate of hemorrhagic transformation following EVT in large core strokes. Results This meta‐analysis showed a statistically significant higher rate of favorable outcome in subjects with extremely large infarct size who undergone EVT compared to those who were managed by medical therapy alone (RR: 1.41, 95% CI: [1.05‐1.98], p: 0.03). In the subgroups of patients with core size &gt; 70ml (RR: 1.51, 95% CI: [1.23‐1.87]), late window presentation (LKN to randomization ≥ 6 hours), (RR: 1.53, 95% CI: [1.27‐1.84]), or those 75 or older than 75 years old (RR: 1.43, 95% CI: [1.12‐1.84]), EVT was associated with higher rates of favorable 90‐day mRS score of 0‐3 compared to medical therapy alone. However, EVT was not associated with better outcomes in those who received IV thrombolysis (RR: 1.37, 95% CI: [0.93‐2.01]. Based on pooled data from SELECT‐2, ANGEL‐ASPECT, and RESCUE Japan trials, the overall rate of early symptomatic hemorrhagic transformation among cases with ASPECT 0‐5 in the thrombectomy group was not significantly higher compared to patients who were managed non‐surgically (OR 1.75, 95% CI: [0.89‐3.47]). Conclusion Endovascular therapy is a reasonable option for the management of large infarcts. EVT results in favorable outcome by a delayed thrombectomy for a large core infarct and in older patients.

Abstract 104: Fetal Posterior Cerebral Artery (PCA) Occlusion from Occluded Cavernous ICA Stent

Introduction Posterior Cerebral Artery (PCA) is a medium vessel occlusion (MVO) which is 5‐10% of all acute ischemic events. Safety and efficacy of mechanical thrombectomy in posterior circulation MVO is unclear compared to medical treatment only (1). There is concern that fragility of distal, smaller vessels may have an increased risk of procedural complications (e.g., arterial dissection and or perforations). More people are getting flow divertors over the years and rate of flow diverter of ICA occlusion is 0.05%‐0.08% (2). Here we present a case of embolic fetal PCA stroke with ICA stent occlusion. Methods We report a case of fetal origin posterior cerebral artery occlusion from ICA with literature search of Pubmed. Results 77 years old female with left cavernous‐ICA stent presented from a rehab facility with complaints of word finding difficulty, confusion, right hemiparesis, right sided neglect, and visual disturbance. In the emergency department (ED), her NIHSS was 28. ED presentation was 2.5 hrs after the last known well (LKW). Of note, patient had a with left cavernous‐ICA stent placement a month before the presentation and was noncompliant to antiplatelets. CT head was negative for intracranial bleeding and ASPECT score was 7. CT angiography head and neck was obtained, showing new complete interval occlusion of the intracranial extradural left ICA with reconstitution of distal branches through anterior communicating artery. Patient received IV thrombolytics, intubated for airway protection and was transferred to a comprehensive stroke center for possible mechanical thrombectomy. Time of the arrival was approximately 6 hours after the LKW, reexamination was hindered by the sedation and intubation but was concerning for possible PCA occlusion rather than ICA occlusion. As the localization of ischemic area was unclear, CT perfusion (CTP) was obtained. CTP showed 27 ml penumbra without core infarct in left PCA territory. As fetal origin of left PCA from ICA is occluded, without ability to access through occluded stent, noted risk of left ICA complications with attempts to recanalize stent for noted PCA hypoperfusion outweigh the benefits. With the exam improvement post thrombolytics administration and small penumbra, mechanical thrombectomy was not indicated. Conclusion In acute large vessel occlusion, utility of CT perfusion (CTP) usually recommended after 6 hours from last well known. In this case, patient presented within the 6 hours but the reexamination post thrombolytics was not localizing to suggest large vessel occlusion (LVO) and the territory at risk was unclear. We described a left intracranial ICA flow diversion occlusion without anterior circulation ischemia and left PCA ischemia demonstrated. In this case, CTP was employed to differentiate the territory at risk for triage to appropriate intervention, to differentiate the LVO vs MVO.

Abstract 217: Influence of CT Perfusion on Decision‐Making for Endovascular Thrombectomy in Distal Occlusions: A Multi‐center Analysis

Introduction There is increasing interest in performing endovascular thrombectomy (EVT) for distal occlusions. Decision making for distal and medium vessel occlusions (DMVO) is variable and factors associated with undergoing the treatment at present remain incompletely characterized. Methods From our prospectively maintained multi‐center registry encompassing four comprehensive stroke centers in the greater Houston area, we identified patients with DMVO acute ischemic stroke (AIS). Patients with occlusions in and beyond the M2 segment, A2 segment, and P2 segment were included. The primary outcome was the likelihood of undergoing EVT, which was analyzed using multivariable logistic regression. We adjusted for time of day of presentation, NIHSS score, ASPECTS, and TPA administration, with the primary independent variable being whether CTP was used in the patient’s evaluation. Secondary outcomes included discharge modified Rankin Scale (mRS), dichotomized 0‐3 vs. 4‐6 Results Among 269 patients with distal occlusions, the median age was 68 (IQR 18), median NIHSS score was 12 (IQR 11), 47.2% were female, and 39.4% received TPA. The most common occlusion locations were M2 (77.7%) followed by P2 (9.7%), and 12.6% comprised the remainder of the occlusions. 166 (61.7%) underwent CTP and 37.9% underwent EVT. Median infarct core on CTP was 18.8 cc and penumbra was 83.1 cc. In multivariable analysis, patients evaluated with CTP were less likely to undergo EVT (OR 0.56 [95% CI ‐1.11;‐0.02]). CTP usage was also associated with a non‐significant reduced likelihood of good discharge outcome (OR 0.59, [95% CI 0.33;1.02]). Conclusion In our multi‐center cohort, patients with DMVO screened with CTP were nearly 50% less likely to undergo EVT. While the modality may assist with occlusion detection, it may also influence whether treatment is offered.

Large vessel occlusion prediction scale thresholds that are sensitive for DAWN Trial patients

Background Large vessel occlusion (LVO) prediction scales are used to triage prehospital suspected stroke patients with a high probability of LVO stroke to endovascular therapy centers. The sensitivities of these scales in the 6-to-24-h time window are unknown. Higher scale score thresholds are typically less sensitive and more specific. Knowing the highest scale score thresholds that remain sensitive could inform threshold selection for clinical use. Sensitivities may also vary between left and right-sided LVOs. Methods LVO prediction scale scores were retrospectively calculated using the National Institutes of Health Stroke Scale (NIHSS) scores of patients enrolled in the DAWN Trial. All patients had last known well times between 6 and 24 h, NIHSS scores ≥ 10, intracranial internal carotid artery or proximal middle cerebral artery occlusions, and mismatches between their clinical severities and infarct core volumes. Scale thresholds with sensitivities ≥ 85% were identified, along with scores ≥ 5% more sensitive for left or right-sided LVOs. Specificities could not be calculated because all patients had LVOs. Results A total of 201 out of 206 patients had the required NIHSS subitem scores. CPSS = 3, C-STAT ≥ 2, FAST-ED ≥ 4, G-FAST ≥ 3, RACE ≥ 5, and SAVE ≥ 3 were the highest thresholds that were still 85% sensitive for DAWN Trial LVO stroke patients. RACE ≥ 5 was the only typically used score threshold more sensitive for right-sided LVOs, though similar small differences were seen for other scales at higher thresholds. Conclusions Our findings likely represent the maximum sensitivities of the LVO prediction scales tested for ideal thrombectomy candidates in the 6-to-24-h time window because NIHSS scores were documented in hospitals during a clinical trial rather than in the prehospital setting. Patients with NIHSS scores &lt; 10 or more distal LVOs would lower sensitivities further. Selecting even higher scale thresholds for LVO triage would lead to many missed LVO strokes.

Abstract 223: Pre‐Thrombectomy Diagnosis of Large Vessel Occlusion with Underlying Intracranial Atherosclerotic Disease

Introduction Intracranial atherosclerotic disease (ICAD) is one of the leading causes of ischemic stroke. We sought to identify variables associated with ICAD underlying large vessel occlusion strokes (LVOS) to facilitate pre‐procedural diagnosis. Methods Retrospective analysis of a prospectively collected thrombectomy single comprehensive stroke center database. Inclusion criteria: anterior circulation occlusion involving the intracranial ICA, MCA‐M1/M2/M3 or ACA(A1‐A2‐A3). ICAD cases were matched for age and sex in a 1:1 ratio to non‐ICAD controls. Results A total of 348 patients were included in the analysis. Patients with ICAD more frequently presented with vascular risk factors. ICAD LVOS showed less frequent atrial fibrillation(AF)(4%vs31%,P=0.001), and lower baseline NIHSS(14vs17,P=0.002) compared to the non‐ICAD group. The ICAD group less frequently showed hyperdense vessel sign and territorial cortical infarcts, but presented more frequently borderzone, deep subcortical and bilateral infarcts on CT compared to the non‐ICAD group. ICAD strokes had higher ASPECTS, and more frequently had calcifications at the carotid siphon as well as multifocal intracranial stenosis on CTA. CTA collaterals scores were comparable between groups. The ICAD group had lower median infarct core volume (1vs12 ml;P&gt;0.001), Tmax&gt;4s (249vs276 ml;P&gt;0.003), and Tmax&gt;6s (97vs140 ml;P&lt;0.003) and higher Tmax&gt;4:6 s ratio (2vs1;P=0.007) on CTP compared to non‐ICAD group. On multivariable analysis, absence of AF, absence of cortical infarcts, presence calcium at ipsilateral carotid siphon, cerebrovascular stroke risk factors burden (DM‐HTN‐Hyperlipidemia‐smoking), borderzone infarcts either (superficial cortical or Internal deep border zone), and multifocal intracranial stenosis were independent factors associated with ICAD. The model (table 1) by AUC for the whole model had sensitivity of 88% [P=&lt;0.001,95%CI(0.84‐0.91)]. Conclusion In patients with anterior circulation LVO strokes, our study suggests that presence of CVS risk factors burden, calcium at carotid siphon, borderzone infract pattern, absence of territorial cortical infarct pattern, multifocal intracranial stenosis, and absence of AF were predictors for ICAD. Additional validation is warranted

Abstract 212: Percutaneous Carotid access in Mechanical Thrombectomy ‐ a safe alternative to transfemoral approach

Introduction Emergent percutaneous carotid artery MER approach for acute ischemic large vessel strokes are rare given the risk of complications and seldom reported. Methods 75‐year‐old left‐handed functional male (mRs:0) with past medical history of HTN, HLD presented to ED after being found on the floor by his family with slurred speech, new onset right sided weakness, with a last known well of 17 hours. NIHSS on arrival was 14 for expressive aphasia, right visual field defect, right facial weakness, significant dysarthria, right hemiparesis, and sensory defect. CT Head demonstrated left MCA territory early ischemic changes. CTA head/neck demonstrated left M1 occlusion with large penumbra. Perfusion data demonstrated no area of core infarct with area of ischemic penumbra in the left MCA territory involving the left frontal, temporal and parietal lobes measuring 161 ml. ASPECT score 5‐6. The patient was deemed a candidate for mechanical endovascular thrombectomy (MER). The procedure was initiated via ultrasound‐guided right common femoral access. After multiple attempts using a wide range of techniques and wire/catheter combinations in order to establish left intracranial access and given extreme angulation/tortuosity/elongation in the proximal left common carotid artery, it was decided to proceed with the catheter position in the left common carotid or the left internal carotid artery that would allow for subsequent catheterization of the intracranial circulation for MER. Results Near complete revascularization with minimal distal thrombus material beyond endovascular reach corresponding to a TICI 2C degree of revascularization was achieved. Closure of the femoral puncture site was performed using an Angio seal femoral closure device. Surgical closure of the puncture site was performed by vascular surgery. The patient was eventually discharged to short term acute rehabilitation and continues to follow up outpatient with the Stroke clinic. Conclusion Older patients with ischemic stroke commonly have tortuous vessels or peripheral vascular disease. As a result, they may greatly benefit from emergent direct carotid access, as the trans‐femoral approach often poses challenges in accessing the thrombus. For patients with complex and unfavorable vascular anatomy for mechanical endo‐vascularization, direct percutaneous carotid puncture can be advantageous, effectively reducing the aforementioned difficulties. When opting for such an approach it is vital to factor in the aortic arch appearance and its branches.

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

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

Numerical modelling of myocardial infarction. II. Analysis of macrophage polarization mechanism as a therapeutic target

In this study, we explore the mechanism of macrophage polarization and its significance in the development of large-scale infarction with favorable outcomes, using a minimal mathematical model of aseptic inflammation dynamics. The problem is considered in the local approximation and in the two-dimensional non-stationary formulation. The study aims to address the pertinent problem of analyzing general principles governing macrophage polarization in the context of devising therapeutic strategies and refining the "therapeutic window". Key trends are identified to enhance the effectiveness of macrophage polarization for therapeutic purposes, along with providing approximate estimations of optimal macrophage interventions that yield organ-preserving and regenerative effects. Our findings reveal that M1/M2 macrophage polarization results from an additive interplay of at least two mechanisms - cytokine-dependent activation and reprogramming of activated macrophages. Furthermore, our modeling data demonstrate the pivotal role of macrophage reprogramming as a direct response to microenvironmental changes, facilitating favorable disease progression and its outcomes. Moreover, we establish that the process of macrophage polarization plays a crucial role in localizing focal inflammation, leading to the formation of the infarction core within finite dimensions and quasi-stationary structure at the periphery, comprising immune cell clusters. The modeling results exhibit qualitative and quantitative agreement with the experimental data. Importantly, the computational experiments results align with the majority of laboratory and clinical studies, emphasizing the therapeutic potential of macrophage polarization management as a promising treatment strategy. The paper is a follow-up of the previously published work series, devoted to the study of spatial and temporal aspects of the inflammation and death processes development in heart muscle cells.

Pericarotid Fat Stranding at Computed Tomography Angiography: A Marker of the Short-Term Prognosis of Acute Ischemic Stroke.

Perivascular epicardial fat stranding detected in the coronary computed tomography (CT) angiography is associated with culprit lesions and provides helpful information on the risk of acute coronary syndrome. This study aimed to evaluate the potential clinical significance of pericarotid fat stranding (PCFS) and investigate the association between PCFS and short-term prognosis in acute stroke using head and neck CT angiography (CTA). This study included 80 patients (mean age, 69.69 ± 11.03; 58 men) who underwent both head and neck CTA and magnetic resonance imaging within a 1-week period. Baseline characteristics, pericarotid adipose tissue attenuation, plaque characteristics, ischemic penumbra, infarct core volume, infarct core growth rate (CGR), and the grade of collateral status were recorded and compared between a PCFS group and a non-PCFS group. Data were compared using the 2-sample t test, Mann-Whitney U test, Fisher exact test, and Spearman rank correlation analysis. We found that patients with PCFS had a significantly higher pericarotid adipose tissue density than patients without PCFS (-55.75 ± 5.53 vs -65.82 ± 9.65, P < 0.001). Patients with PCFS showed a larger infarct core volume (166.43 ± 73.07 vs 91.43 ± 55.03, P = 0.001) and faster CGR (39.57 ± 12.01 vs 19.83 ± 32.77; P < 0.001), and the frequency of adverse prognosis was more significant than in control participants (83.33% vs 19.11%). Individuals with PCFS showed higher CGR, which was substantially related to worse outcomes in patients with acute stroke with ipsilateral carotid atherosclerosis. Recognition of PCFS may help predict stroke prognosis and allow doctors to take early action to improve patient prognosis.