Abstract 1122‐000243: Capacity and Characteristics of Thrombectomy Centers World‐wide Using the MT2020+ Global Thrombectomy Tracking Smartphone App

Introduction : Mechanical thrombectomy (MT) has been established as a first line therapy for large vessel occlusion stroke; however, MT remains underutilized globally with massive disparity in access based on country income level. Mission Thrombectomy 2020+ (MT2020+) is a global alliance and campaign that aims to reduce this disparity and democratize MT access for patients. A novel smartphone application, Global Thrombectomy Tracking App, was designed to characterize thrombectomy centers on a global‐level and numerically track MT cases in near real‐time. Methods : The MT2020 App was launched in November 2019. To gain insight into local systems of care, neurointerventionalists were prompted to participate in an optional 11‐question survey over a 19‐month period. Questions pertained to population density, organizational structure, academic affiliation, available imaging modalities, tPA usage, and case volumes. Results : Of 338 active users from 9 countries, 49‐neurointerventionalists participated in the survey. The majority (71.5%) practiced in large metropolis with population >1‐million, of which 16.3% were in mega‐cities (>10‐million). The centers were government funded (46.9%), private (40.8%) or charitable (12.2%). Most were academic hospitals (81.6%) with neurointerventional trainees (55.1%). At most centers (87.7%), IV‐tPA was available with annual treatment rate >5% for 55.1%. Most centers (57.1%) utilize additional CT perfusion scans prior to MT. For 69.3% respondents, the annual MT case volume was between 10–100 cases. Conclusions : Our survey analysis shows that the global MT tracking APP can generate important thrombectomy capacity and characteristics at regional levels on a global scale, which can be used for targeted funding and resource allocation to accelerate access to MT.

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Abstract WP334: Stroke Case Volume After Implementation of the 24 Hour Extended Intra-Arterial Thrombectomy Window

Stroke ◽

10.1161/str.51.suppl_1.wp334 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Jessica Glenn ◽

Sharon Heaton ◽

Ciarán Powers ◽

Shahid Nimjee ◽

Patrick Youssef ◽

...

Keyword(s):

Systems Of Care ◽

Ct Perfusion ◽

Stroke Patients ◽

Case Volume ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Number Of Patients ◽

Comprehensive Stroke Center ◽

The Impact ◽

Treatment Window

Introduction: The results of the DAWN and DEFUSE 3 trials demonstrated improved functional outcome with mechanical thrombectomy (MT) in stroke patients who present with anterior circulation large vessel occlusion (LVO) up to a 24 hours after last known well. The AHA guidelines were updated to include this recommendation in 2018, but the impact of the increase in number of patients treated in clinical practice remains unknown. Methods: We reviewed ischemic stroke MT patients admitted to a comprehensive stroke center (DEFUSE 3 trial participating site), from July 2015- July 2019. Our center instituted a 24 hour IAT window protocol in March 2018 (Figure 1). Eligibility for MT in the 24 hour window followed the DEFUSE 3 criteria including the presence of LVO, National Institute of Health Stroke Scale (NIHSS) > 6, and favorable CT perfusion imaging. Results: During this 4-year period, 290 stroke patients with LVO received MT at our institution. MT volumes increased in each subsequent year in this study as follows: July 2015 (44), July 2016 (58), July 2017 (73) and July 2018 (115). An increase in MT volume was observed after the expansion of the treatment window to 24 hours (Figure 2). In the period prior to the expanded 24 hour treatment window, MT volumes were 25-33 per 6 month period. After the 24 hour treatment window was started, MT volumes were 58-60 per 6 month period. Conclusions: Expanding the MT window to 24 hours has nearly doubled the MT case volume at our single center. This dramatic increase in IAT clinical utilization observed with expansion to the 24 hour window has implications for systems of care and resource optimization of the stroke patient.

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Epidemiological Surveillance of the Impact of the COVID-19 Pandemic on Stroke Care Using Artificial Intelligence

Stroke ◽

10.1161/strokeaha.120.031960 ◽

2021 ◽

Author(s):

Raul G. Nogueira ◽

Jason M. Davies ◽

Rishi Gupta ◽

Ameer E. Hassan ◽

Thomas Devlin ◽

...

Keyword(s):

Artificial Intelligence ◽

Acute Stroke ◽

Systems Of Care ◽

Ct Perfusion ◽

Stroke Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Number Of Patients ◽

The Impact

Background and Purpose: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. Methods: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. Results: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (−22.8%; 1.39–1.07 patients/day per hospital, P <0.001) and CT perfusion (−26.1%; 0.50–0.37 patients/day per hospital, P <0.001) as well as in the incidence of large vessel occlusion (−17.1%; 0.15–0.13 patients/day per hospital, P <0.001) and severe strokes on CT perfusion (−16.7%; 0.12–0.10 patients/day per hospital, P <0.005). The sampled cohort showed similar declines in the rates of large vessel occlusions versus thrombectomy (18.8% versus 19.5%, P =0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P =0.4). Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.

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Abstract W P21: Should We Perform Thrombectomy In Patients With Wake-up Strokes? A Case Series Using Ct Perfusion For Patient Selection

Stroke ◽

10.1161/str.46.suppl_1.wp21 ◽

2015 ◽

Vol 46 (suppl_1) ◽

Author(s):

Gabriel Vidal ◽

James Milburn ◽

Garrett Bennett ◽

Vivek Sabharwal ◽

Mustafa Al Hasan

Keyword(s):

Risk Factors ◽

Ct Perfusion ◽

Medical Center ◽

Case Series ◽

Stroke Severity ◽

Vessel Occlusion ◽

Single Center Experience ◽

Aspiration Technique ◽

Group 2

Background and objectives: Approximately 25% of patients who present with acute ischemic stroke are wake-up strokes. These patients are often not treated with IV thrombolytics because of unclear onset of symptoms. Little data exists on endovascular therapy as acute treatment for this population, particularly with an aspiration technique. The objective of this study is to compare outcomes of patients who presented with wake-up strokes due to large vessel occlusion treated with neuroendovascular procedures versus those who received conservative treatment, based on a 2-year (2012-2013), single center experience at Ochsner Medical Center in New Orleans, LA. Method: 24 consecutive patients, who presented with wake-up strokes, were outside the IV tPA window, and had both CTA confirmed intracranial LVO and CT-perfusion data upon arrival to our institution were retrospectively studied. Patients with hemorrhages, tandem lesions, or high-grade carotid stenosis were excluded from this analysis. Decision to perform endovascular treatment was made by the vascular neurologist and neuro-interventionalist based on stroke severity and CTA/perfusion data. Patients in group 1 (n = 8) underwent endovascular revascularization procedures; patients in group 2 (n = 16) were treated conservatively (medical management alone). Presentation NIHSS, risk factors, mortality, discharge NIHSS, discharge mRS, and follow up mRS were compared. Results: There were no statistical differences in patient population regarding age, gender, and risk factors. There was no statistical difference in their initial NIHSS (16.8 vs. 21.8, p=0.05162), or mortality (0% vs 21%, pr=0.262). The two groups were statistically different in their discharge NIHSS (7.25 vs 21.81, p<0.00045), discharge mRS (2 vs 5, p<0.00001), clinic follow up mRS (1.37 vs 4.94, p<0.00001), and good outcome at discharge (mRS 0-2)(75% vs 0%, pr<0.0002). Conclusion: Patients with wake-up strokes, LVO, and favorable CT-perfusion data who underwent neuroendovascular reperfusion treatment had significantly better outcomes in our population, despite similar stroke severity at presentation. This suggests that with careful selection, neuroendovascular therapy for wake-up strokes may lead to improved outcomes.

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Prognostic importance of CT ASPECTS and CT perfusion measures of infarction in anterior emergent large vessel occlusions

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2018-014461 ◽

2018 ◽

Vol 11 (7) ◽

pp. 670-674 ◽

Cited By ~ 3

Author(s):

Syed Ali Raza ◽

Clara M Barreira ◽

Gabriel M Rodrigues ◽

Michael R Frankel ◽

Diogo C Haussen ◽

...

Keyword(s):

Ct Perfusion ◽

Area Under The Curve ◽

Large Vessel ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Nihss Score ◽

Median Baseline ◽

Ct Head ◽

Prognostic Importance ◽

Contrast Ct

BackgroundAge, neurologic deficits, core volume (CV), and clinical core or radiographic mismatch are considered in selection for endovascular therapy (ET) in anterior circulation emergent large vessel occlusion (aELVO). Semiquantitative CV estimation by Alberta Stroke Programme Early CT Score (CT ASPECTS) and quantitative CV estimation by CT perfusion (CTP) are both used in selection paradigms.ObjectiveTo compare the prognostic value of CTP CV with CT ASPECTS in aELVO.MethodsPatients in an institutional endovascular registry who had aELVO, pre-ET National Institutes of Health Stroke Scale (NIHSS) score, non-contrast CT head and CTP imaging, and prospectively collected 3-month modified Rankin Scale (mRS) score were included. Age- and NIHSS-adjusted models, including either CT ASPECTS or CTP volumes (relative cerebral blood flow <30% of normal tissue, total hypoperfusion, and radiographic mismatch), were compared using receiver operator characteristic analyses.ResultsWe included 508 patients with aELVO (60.8% M1 middle cerebral artery, 34% internal carotid artery, mean age 64.1±15.3 years, median baseline NIHSS score 16 (12–20), median baseline CT ASPECTS 8 (7–9), mean CV 16.7±24.8 mL). Age, pre-ET NIHSS, CT ASPECTS, CV, hypoperfusion, and perfusion imaging mismatch volumes were predictors of good outcome (mRS score 0–2). There were no differences in prognostic accuracies between reference (age, baseline NIHSS, CT ASPECTS; area under the curve (AUC)=0.76) and additional models incorporating combinations of age, NIHSS, and CTP metrics including CV, total hypoperfusion or mismatch volume (AUCs 0.72–0.75). Predicted outcomes from CT ASPECTS or CTP CV-based models had excellent agreement (R2=0.84, p<0.001).ConclusionsIncorporating CTP measures of core or penumbral volume, instead of CT ASPECTS, did not improve prognostication of 3-month outcomes, suggesting prognostic equivalence of CT ASPECTS and CTP CV.

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Abstract WMP14: Accuracy of Smartphone-based Evaluation of Large Vessel Occlusion on CTA

Stroke ◽

10.1161/str.48.suppl_1.wmp14 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Douglas T Hidlay ◽

Ryan McTaggart ◽

Shadi Yaghi ◽

Eleanor Dibiasio ◽

Eric Tung ◽

...

Keyword(s):

Head And Neck ◽

Mechanical Thrombectomy ◽

Smartphone Application ◽

Large Vessel ◽

Complete Agreement ◽

Kappa Statistics ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Observer Reliability ◽

Actual Use

Introduction: Since mechanical thrombectomy was established as the gold standard for treatment of stroke caused by an emergent large vessel occlusion (ELVO), comprehensive stroke centers have worked to streamline their workflow and minimize time-to-intervention; the ability to rapidly review CT angiography (CTA) is one hurdle in that process. To that end, we evaluated the diagnostic accuracy and confidence in review of CTA of the head and neck for ELVO via a smartphone-based application (LifeImage) as compared to review on a PACS workstation. Methods: Seventy-six head and neck CTA studies performed for potential stroke from one comprehensive and seven primary stroke centers were independently reviewed remotely on smartphone by two blinded neurointerventional radiologists in actual-use circumstances. The presence and location of large vessel occlusion(s), diagnostic quality, and confidence in interpretation were recorded. Comparison was made to blinded review of these studies on a PACS workstation performed at a delayed interval. Kappa statistics were calculated to evaluate intra- and inter-observer reliability. Results: Over 76 studies, occlusion of the M1 segment was demonstrated in 14 (18%); carotid artery in 2 (3%); tandem carotid and M1 in 2 (3%); basilar artery in 2 (3%); and no large vessel occlusion in 56 (73%). There was complete agreement between CTA interpretations on smartphone and on PACS with excellent intra- and inter-observer reliability (Table 1). No ELVOs were missed on smartphone review of these studies. Conclusion: In actual-use circumstances, experienced neurointerventional radiologists are able to utilize a smartphone application to diagnose an ELVO on CTA as accurately as on a PACS workstation with similar levels of confidence. These findings support the use of mobile electronic devices by stroke networks to rapidly triage patients for mechanical thrombectomy.

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Abstract P355: Real-Word Performance of Two Automated Software Platforms for Identification of Salvageable Tissue in Stroke Patients: A Single Center Experience

Stroke ◽

10.1161/str.52.suppl_1.p355 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Angelos Katramados ◽

Horia Marin ◽

Maximilian Kole ◽

Owais Alsrouji ◽

Pala Varun ◽

...

Keyword(s):

Ct Perfusion ◽

Stroke Patients ◽

Vessel Occlusion ◽

Significant Discrepancy ◽

Endovascular Thrombectomy ◽

Stroke Treatment ◽

Software Platforms ◽

Automated Software ◽

Selection Of Patients ◽

Selection Of

Background and purpose: Modern stroke treatment has been revolutionized by image-guided selection of patients for endovascular thrombectomy. Current automated platforms allow for real-time identification of large vessel occlusion and salvageable brain tissue. We sought to evaluate the performance of these platforms with regard to identification of infarcted and salvageable tissue. Methods: We studied all patients that presented to Henry Ford Health System hospitals over a period of 6 weeks, received CT perfusion imaging of the brain upon initial presentation. The images were processed with two automated software platforms. We prospectively measured volumes of tissue with cerebral blood flow (CBF) < 30% of contralateral hemisphere, Tmax >6 secs, and hypoperfusion indices (defined as the ratio of volumes Tmax>10 secs and Tmax>6 secs). We compared the outputs of the two platforms and analyzed the performance of each platform. Results: 66 scans were included in our study. Both platforms were able to image all stroke patients within their FDA-approved indications. With regard to all scans, both platforms were noted to demonstrate comparable CBF<30% volumes (6.32 ml. vs 4.97 ml, p=0.276), and hypoperfusion indices (0.278 vs 0.338, p=0.344). However, there was statistically significant discrepancy in the volumes of tissue with Tmax>6 secs (23.96 vs 14.18 ml, p=0.023). Analysis of a subset of 12 scans, with evidence of LVO or severe symptomatic stenosis on corresponding CTA, showed again comparable CBF<30% volumes (12.84 ml vs 13.67 ml, p=0.725), and hypoperfusion indices (0.344 vs 0.314, p=0.699). However, the Tmax>6 secs volume discrepancy was greater and still statistically significant (75.54 ml vs 39.58 ml, p=0.048) Conclusions: Automated software platforms are an invaluable aid in the identification of salvageable tissue, and selection of patients for endovascular thrombectomy in the 6-24 hour window. However, the substantial difference in the identified volumes of hypoperfused tissue-at-risk may result in largely different clinical decisions and patient outcomes. Further validation efforts (and harmonization of algorithms) are required. Stroke teams should be aware of the limitations of automated analysis and need for expert review.

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Abstract WP280: A Potential Scoring System to Predict Infarct Progression During Inter Facility Transfer of Patients for Endovascular Thrombectomy Evaluation

Stroke ◽

10.1161/str.51.suppl_1.wp280 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Sujan Teegala Reddy ◽

Elliott Friedman ◽

Tzu-Ching Wu ◽

Xu Zhang ◽

Jing Zhang ◽

...

Keyword(s):

Systems Of Care ◽

Youden Index ◽

Coefficient Estimates ◽

Anterior Circulation ◽

Eligibility Criteria ◽

Vessel Occlusion ◽

Hub And Spoke ◽

Endovascular Thrombectomy ◽

Stroke Systems Of Care ◽

Current Guidelines

Introduction: Current guidelines recommend CT ASPECTS≥6 as eligibility criteria for endovascular thrombectomy (EVT), a proven therapy for anterior circulation large vessel occlusion (ACLVO). Infarct progression during inter-facility transfer can render many patients ineligible for EVT. We developed a score utilizing clinical and imaging variables to predict infarct progression. Methods: Patients with ACLVO transferred from a referring hospital (RH) to our EVT capable center between August 2015 and December 2018 were reviewed. Significant predictors (p<0.10) of infarct progression, defined as CT ASPECTS of ≥6 at RH to <6 at hub, were identified using a logistic regression model. Regression coefficient estimates were used to score selected variables. The optimal cut-point was selected based on evaluated Youden index. Results: A total of 132 patients were analyzed. Score ranged from 0 to theoretical limit 18 (table 1): CTA collateral score (2/3/4=0, 0/1=3), Clot location (not ICA/M2=0, M2=2, ICA/M1=3), NIHSS (0-14=0, ≥15=5), use of antiplatelet by history (Yes=0, No=3), CT ASPECTS at RH (10=0, 6-9=2). Patients with score of ≥10.0 were more likely to have infarct progression (OR=22.15, 95% CI 4.99 - 98.35, p<0.001). Conclusions: Our score utilizing clinical and imaging variables provides information on which patients with ACLVO may undergo infarct progression during inter-facility transfer. We plan to externally validate our findings in another hub and spoke network. This score may potentially aid decisions to develop stroke systems of care to triage patients with ACLVO within hub and spoke networks.

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Abstract TP77: Impact of Time and Aspects on Clinical Core Mismatch in Large Vessel Occlusion Strokes

Stroke ◽

10.1161/str.51.suppl_1.tp77 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Shashvat Desai ◽

Bradley J Molyneaux ◽

Marcelo Rocha ◽

Matthew Starr ◽

Tudor G Jovin ◽

...

Keyword(s):

Patient Selection ◽

Time Window ◽

Ct Perfusion ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Ct Head ◽

Ischemic Core ◽

The Impact ◽

Core Volume

Introduction: Patient selection for endovascular thrombectomy (EVT) for anterior circulation large vessel occlusion (LVO) strokes in the 6-24-hour time window is dependent on delineating clinical core mismatch (CCM) as defined by DAWN trial criteria. In contrast, patient selection in the early window (0-6 hours) can be performed using ASPECTS on CT head. We aim to determine the prevalence of DAWN-CCM in LVO strokes and the impact of time and ASPECTS. Methods: Retrospective analysis of large vessel occlusion [internal carotid and middle cerebral artery-M1] strokes at a CSC. Consecutive patients who underwent CT perfusion or MRI within 120 minutes of CT head were included in the study (treated and untreated). Ischemic core volume was assessed using RAPID [IschemaView] and ASPECTS using automated ASPECTS [Brainomix]. CCM was defined using DAWN trial criteria [DAWN-CCM: NIHSS ≥10 and core <31 ml, NIHSS ≥20 and core <51 ml]. Results: A total of 116 patients were included. Mean age was 71 ±14 and 62% were females. Mean ischemic core volume and median ASPECTS were 46 ±65 ml and 8 (6-9), respectively. In patients with NIHSS score ≥10 (98), 57% had DAWN-CCM in the 0-24-hour window. Proportion of patients with DAWN-CCM in 6-24-hour window was 70% (6-12 hours), 50% (12-18 hours), and 50% (18-24 hours) [p=0.35]. Proportion of patients with DAWN-CCM by ASPECTS group was 88% (ASPECTS 9-10), 64% (ASPECTS 6-8) and 13% (ASPECTS 0-5) [p=<0.01] (Figure 1). Probability of DAWN-CCM declines by 7% for every 2 hours increase in TLKW to imaging, and by 13% for every 1-point decrease in ASPECTS. Conclusion: Approximately 57% of LVO strokes have clinical core mismatch. LVO strokes with DAWN-CCM decline with increasing time and decreasing ASPECTS. ASPECTS alone may be sufficient to identify patients with DAWN-CCM in a resource limited setting and avoid time consuming advanced imaging.

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Abstract WP82: Ghost Infarct Core: Ischemic Oreoverestimation by Admission CT Perfusion on Large Vessel Occlusion Stroke Patients

Stroke ◽

10.1161/str.50.suppl_1.wp82 ◽

2019 ◽

Vol 50 (Suppl_1) ◽

Author(s):

Gabriel M Rodrigues ◽

Michael Frankel ◽

Diogo C Haussen ◽

Raul G Nogueira

Keyword(s):

Ct Perfusion ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Stroke Patients ◽

Infarct Core ◽

Vessel Occlusion

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Association of collateral status and ischemic core growth in patients with acute ischemic stroke

Neurology ◽

10.1212/wnl.0000000000011258 ◽

2020 ◽

pp. 10.1212/WNL.0000000000011258

Author(s):

Longting Lin ◽

Jianhong Yang ◽

Chushuang Chen ◽

Huiqiao Tian ◽

Andrew Bivard ◽

...

Keyword(s):

Growth Rate ◽

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Ct Perfusion ◽

Study Cohort ◽

Vessel Occlusion ◽

Ischemic Core ◽

Relationship Of ◽

The Relationship ◽

Linear Regressions

ObjectiveTo test the hypothesis that acute ischemic patients with poorer collaterals would have faster ischemic core growth, we included 2 cohorts in the study, cohort 1 of 342 patients for derivation and cohort 2 of 414 patients for validation purpose.MethodsAcute ischemic stroke patients with large vessel occlusion were included. Core growth rate was calculated by the following equation: Core growth rate = Acute core volume on CTP/Time from stroke onset to CTP. Collateral status was assessed by the ratio of severe hypoperfusion volume within the hypoperfusion region of CTP. The CTP collateral index was categorized in tertiles; for each tertile, core growth rate was summarized as median and inter-quartile range. Simple linear regressions were then performed to measure the predictive power of CTP collateral index in core growth rate.ResultsFor patients allocated to good collateral on CT perfusion (tertile 1 of collateral index), moderate collateral (tertile 2), and poor collateral (tertile 3), the median core growth rate was 2.93 mL/h (1.10–7.94), 8.65 mL/h (4.53–18.13), and 25.41 mL/h (12.83–45.07) respectively. Increments in the collateral index by 1% resulted in an increase of core growth by 0.57 mL/h (coefficient = 0.57, 95% confidence interval = [0.46, 0.68], p < 0.001). The relationship of core growth and CTP collateral index was validated in cohort 2. An increment in collateral index by 1% resulted in an increase of core growth by 0.59 mL/h (coefficient = 0.59 [0.48–0.71], p < 0.001) in cohort 2.ConclusionCollateral status is a major determinant of ischemic core growth.

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