Global impact of COVID-19 on stroke care

Background

The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide.

Aims

We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior).

Methods

Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers.

Results

The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p < 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions.

Conclusion

The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.

Intraluminal Carotid Artery Thrombus in COVID-19: Another Danger of Cytokine Storm?

Coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Inflammation affects atherosclerotic plaque vulnerability and promotes a thrombogenic environment. We report a series of 6 patients with COVID-19 with acute ischemic stroke due to intraluminal carotid artery thrombus presenting during an 8-day period. Six patients were included (5 men) with a mean age of 65.8 years (range, 55-78 years). COVID-19 was diagnosed by detection of Severe Acute Respiratory Syndrome coronavirus 2 in 5 patients and was presumed due to typical clinical and imaging findings in 1 patient. All patients had vascular risk factors including diabetes (83%), hyperlipidemia (100%), and smoking (17%). Four patients presented with large infarcts with initial NIHSS scores of 24-30. During their hospitalization, all patients had elevated D-dimer and C-reactive protein levels, 5 patients had elevated lactate dehydrogenase and ferritin levels, 3 had elevated interleukin-6 levels, and 2 had elevated troponin levels. Inflammation related to COVID-19 may result in rupture of vulnerable atherosclerotic plaques, resulting in thrombosis and acute ischemic stroke.

CTA-for-All: Impact of Emergency Computed Tomographic Angiography for All Patients With Stroke Presenting Within 24 Hours of Onset

Background and Purpose- We sought to evaluate the impact of a Computed Tomographic Angiography (CTA) for All emergency stroke imaging protocol on outcome after large vessel occlusion (LVO). Methods- On July 1, 2017, the Henry Ford Health System implemented the policy of performing CTA and noncontrast computed tomography together as an initial imaging study for all patients with acute ischemic stroke (AIS) presenting within 24 hours of last known well, regardless of baseline National Institutes of Health Stroke Scale score. Previously, CTA was reserved for patients presenting within 6 hours with a National Institutes of Health Stroke Scale score ≥6. We compared treatment processes and outcomes between patients with AIS admitted 1 year before (n=388) and after (n=515) protocol implementation. Results- After protocol implementation, more AIS patients underwent CTA (91% versus 61%; P<0.001) and had CTA performed at the same time as the initial noncontrast computed tomography scan (78% versus 35%; P<0.001). Median time from emergency department arrival to CTA was also shorter (29 [interquartile range, 16-53] versus 43 [interquartile range, 29-112] minutes; P<0.001), more cases of LVO were detected (166 versus 96; 32% versus 25% of all AIS; P=0.014), and more mechanical thrombectomy procedures were performed (108 versus 68; 21% versus 18% of all AIS; P=0.196). Among LVO patients who presented within 6 hours of last known well, median time from last known well to mechanical thrombectomy was shorter (3.5 [interquartile range, 2.8-4.8] versus 4.1 [interquartile range, 3.3-5.6] hours; P=0.038), and more patients were discharged with a favorable outcome (Glasgow Outcome Scale 4-5, 53% versus 37%; P=0.029). The odds of having a favorable outcome after protocol implementation was not significant (odds ratio, 1.84 [95% CI, 0.98-3.45]; P=0.059) after controlling for age and baseline National Institutes of Health Stroke Scale score. Conclusions- Performing CTA and noncontrast computed tomography together as an initial assessment for all AIS patients presenting within 24 hours of last known well improved LVO detection, increased the mechanical thrombectomy treatment population, hastened intervention, and was associated with a trend toward improved outcome among LVO patients presenting within 6 hours of symptom onset.

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

Background

During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.

Methods

We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.

Findings

There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170–1035 procedures, respectively, representing an 11.5% (95%CI −13.5% to −9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI −28.0% to −22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.

Interpretation

There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.

Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: A 1-Year Follow-up

BACKGROUND AND OBJECTIVES

Declines in stroke admission, IV thrombolysis (IVT), and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the effect of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), IVT, and mechanical thrombectomy over a 1-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020).

METHODS

We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, IVT treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.

RESULTS

There were 148,895 stroke admissions in the 1 year immediately before compared with 138,453 admissions during the 1-year pandemic, representing a 7% decline (95% CI [95% CI 7.1-6.9]; p < 0.0001). ICH volumes declined from 29,585 to 28,156 (4.8% [5.1-4.6]; p < 0.0001) and IVT volume from 24,584 to 23,077 (6.1% [6.4-5.8]; p < 0.0001). Larger declines were observed at high-volume compared with low-volume centers (all p < 0.0001). There was no significant change in mechanical thrombectomy volumes (0.7% [0.6-0.9]; p = 0.49). Stroke was diagnosed in 1.3% [1.31-1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82-2.97], 5,656/195,539) of all stroke hospitalizations.

DISCUSSION

There was a global decline and shift to lower-volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared with the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year.

TRIAL REGISTRATION INFORMATION

This study is registered under NCT04934020.

Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19: The Global COVID-19 Stroke Registry

BACKGROUND AND OBJECTIVES

COVID-19-related inflammation, endothelial dysfunction, and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with acute ischemic stroke (AIS). We aimed to evaluate the safety and outcomes of revascularization treatments in patients with AIS and COVID-19.

METHODS

This was a retrospective multicenter cohort study of consecutive patients with AIS receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March 2020 and June 2021 tested for severe acute respiratory syndrome coronavirus 2 infection. With a doubly robust model combining propensity score weighting and multivariate regression, we studied the association of COVID-19 with intracranial bleeding complications and clinical outcomes. Subgroup analyses were performed according to treatment groups (IVT-only and EVT).

RESULTS

Of a total of 15,128 included patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19; of those, 5,848 (38.7%) patients received IVT-only and 9,280 (61.3%) EVT (with or without IVT). Patients with COVID-19 had a higher rate of symptomatic intracerebral hemorrhage (SICH) (adjusted OR 1.53; 95% CI 1.16-2.01), symptomatic subarachnoid hemorrhage (SSAH) (OR 1.80; 95% CI 1.20-2.69), SICH and/or SSAH combined (OR 1.56; 95% CI 1.23-1.99), 24-hour mortality (OR 2.47; 95% CI 1.58-3.86), and 3-month mortality (OR 1.88; 95% CI 1.52-2.33). Patients with COVID-19 also had an unfavorable shift in the distribution of the modified Rankin score at 3 months (OR 1.42; 95% CI 1.26-1.60).

DISCUSSION

Patients with AIS and COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after revascularization treatments than contemporaneous non-COVID-19 patients receiving treatment. Current available data do not allow direct conclusions to be drawn on the effectiveness of revascularization treatments in patients with COVID-19 or to establish different treatment recommendations in this subgroup of patients with ischemic stroke. Our findings can be taken into consideration for treatment decisions, patient monitoring, and establishing prognosis.

TRIAL REGISTRATION INFORMATION

The study was registered under ClinicalTrials.gov identifier NCT04895462.

Non-stenosing carotid artery plaques in embolic stroke of undetermined source: a retrospective analysis

BACKGROUND

We aim to identify the association between high-risk carotid plaques and their laterality to stroke in ESUS patient population. We also discuss recurrent stroke events and their laterality to the index stroke.

METHODS

This was a retrospective study. We reviewed data for patients with ESUS between June 20, 2016, and June 20, 2021. Using computed tomography angiography, we analyzed plaque features that are associated with ESUS, and then, we identified the recurrent stroke events and characterized lateralization to the index stroke.

RESULTS

Out of 1779 patients with cryptogenic ischemic stroke, we included 152 patients who met the criteria for ESUS. High-risk plaque features were found more often ipsilateral to the stroke side when compared contralaterally: plaque ulceration (19.08% vs 5.26%, p < .0001), plaque thickness > 3 mm (19.08% vs 7.24%, p = 0.001), and plaque length > 1 cm (13.16% vs 5.92%, p = 0.0218). There was also a significant difference in plaque component in which both components (soft and calcified) and only soft plaques were more prevalent ipsilaterally (42.76% vs 23.68% and 17.76% vs 9.21%, respectively, p < .0001). Of the 152 patients, 17 patients were found to have a recurrent stroke event, and 47% (n = 8) had an ipsilateral stroke to the index event. Moreover, stroke was bilateral in 41% of the patients (n = 7), and contralateral in 12% (n = 2).

CONCLUSION

High-risk plaque features studied here were more prevalent ipsilaterally to the stroke side in ESUS than contralaterally. Multicenter studies are needed to form precise prediction models and scoring systems to help guide treatment, i.e., choice of medical therapy and/or revascularization.

Abstract TP95: Utility Of Automated Artificial Intelligence Software In The Analysis Of Ct Perfusion With Acetazolamide Challenge For The Assessment Of Cerebrovascular Reserve In Patients With Cervico-cranial Arterial Stenoses And Occlusions

Background: Cerebrovascular reserve (CVR) assessment is valuable in predicting stroke risk in patients with cranio-cervical stenoses and occlusions. CTP with Acetazolamide challenge (AC) allows a qualitative and quantitative assessment of CVR but is limited by ROI positioning, motion and software. Artificial intelligence (AI) automated software with delay in arrival correction has been validated for the processing of CTP data for acute stroke and may more easily detect abnormal CVR. We sought to compare the results of image-processing with a standard platform (Vitrea™) and AI platform (RAPID™).

Methods: Retrospective analysis of an IRB approved prospective database of patients who had CTP with acetazolamide (1g IV) who also had a stenosis/occlusion of the internal carotid or middle cerebral arteries was performed. Symptomatic status was defined as recurrent symptoms related to the vessel of interest within 6 months of scan. Two readers, blinded to the clinical scenario, independently reviewed the CTP datasets and identified CBF regional abnormalities and changes post AC using the 2 different platforms. Abnormal CVR was defined as an increase of CBF post AC of <25% of the baseline in the region of interest with Vitrea™, and an expansion of the volume of tissue with CBF<30% using RAPID™. CTP analyses were correlated with the clinical presentation.

Results: Thirty patients fulfilling criteria received CTP before and after AC. 24 patients (80%) were symptomatic. Vitrea™ detected decrease in CBF pre-AC in 27 patients and worsening CBF value post-AC in 19 patients. 10 Patients had an increase >25% in CBF post AC. Rapid™ detected 5 patients with CBF lesion <30% pre-AC. Expansion of the CBF lesion occurred in 8 patients post-AC with a mean change in volume of 7.7 ml (P-value=0.002). The sensitivity for the detection of poor CVR in patients with recurrent symptoms was 80% (95% CI 59.30 - 93.17) with Vitrea™ and 45% (95% CI 25.55%-67.18%) with RAPID™.

Conclusion: Automated post processing software with delay in arrival correction algorithm is less sensitive to abnormal CVR and has lower correlation with clinical presentation in this small cohort. Further study is warranted to identify thresholds that may better correlate.

The role of non-stenosing carotid artery plaques in embolic stroke of undetermined source, is it a silent offender? A review of literature

PURPOSE

Atherosclerotic cervical internal carotid artery disease is one of the major causes of ischemic stroke and transient ischemic attacks. The risk of stroke from mild to moderate stenoses (i.e. <50% stenosis) might be underestimated. There is increasing evidence that plaque morphological features reflect plaque instability that may harbor high risk for embolization. In this narrative review, we will review the literature on plaque features that predict vulnerability beyond the degree of stenosis, discuss the clinical association with stroke, and evaluate the evidence that these lesions serve as a source for embolic stroke of unknown source (ESUS).

METHODS

We performed a literature search using PubMed, EMBASE, and Web of Science. The terms "embolic stroke of undetermined source" and "plaque morphology" were used either alone or in combination with "non-flow limiting stenosis," "non-stenosing plaques," "high-risk plaque features" or "internal carotid artery plaque." Data on plaque morphology and ESUS were mainly taken from review articles, observational studies including retrospective cohort and cross-sectional studies, meta-analyses, and systematic reviews.

CONCLUSION

Nonstenosing carotid artery plaques with high-risk features carry a remarkable risk for stroke occurrence and randomized clinical trials are warranted for further evaluation of using carotid artery stenting or carotid endarterectomy to mitigate the risk of stroke.

Abstract TP160: The Non-stenosing Carotid Artery Plaque In Embolic Stroke Of Undetermined Source: A Retrospective Study

Introduction: Atherosclerotic cervical ICA disease is one of the major causes of ischemic stroke. The risk of stroke from mild to moderate stenoses (i.e., <50% stenosis) might be underestimated. Further investigation is mandated to describe the association between high-risk plaque features and ESUS.

Methods: This was a retrospective observational study. Using the stroke registry of our hospital's system between June 20th 2016 and June 20th 2021, we reviewed data for patients diagnosed with ESUS according to previously published definition criteria. Using CTA, we analyzed laterality of high-risk plaque features in relation to the stroke side, and then we identified the incidence of recurrent stroke events.

Results: Out of 1779 patients with cryptogenic ischemic stroke, only 152 met the inclusion criteria for ESUS. We Compared high-risk plaque features ipsilateral to stroke side as to contralaterally. There were significantly more ulcerations defined as >1 mm depression (19.08% vs 5.26%, p<.0001), plaque thickness >3 mm (19.08% vs 7.24%, p=0.001), and plaque length >1cm (13.16% vs 5.92%, p=0.0218). Also, there was a significant difference in stenosis of ipsilateral to stroke when compared contralaterally, especially for stenoses of 10-30% and 31-49% (17.76% vs 10.53% and 5.26% vs 2.63%, respectively. p=0.0327). There was also a significant difference in plaque component; both components (soft and calcified) and only soft plaque (42.76% vs 23.68% and 17.76% vs 9.21%, respectively. p<.0001) were more prevalent ipsilaterally. In total, 17 patients were found to have a recurrent stroke event, 8 patients had an ipsilateral stroke to the index event, 7 had a bilateral and 2 had a contralateral event.

Conclusion: ESUS is more commonly found ipsilateral to high-risk plaque features. The small number of our sample is definitely a limitation. Further large and multicenter studies aiming to form precise prediction models and scoring systems are needed to help guide treatment.

Abstract TP17: Outcomes in Octogenarians Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke: A Single Center Experience

Background: Mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in the elderly presents a unique set of challenges and opportunities. Most existing studies include patients up to the age of 90 with stricter criteria of inclusion for patients ≥ 80 years of age. The following study compares the outcomes in octogenarians compared to younger patients in a single center.

Methods: We conducted a retrospective chart review of patients who were ≥ 80yo who underwent MT from March 2016 to July 2019. Data on age, recanalization score measured by Thrombolysis in Cerebral Infarction (TICI) score and clinical outcomes were compared to 126 patients < 80 years of age treated during the same time period. Clinical outcomes were classified based on modified Rankin score (mRS) at discharge. Poor outcomes were defined as mRS 4-6. Good recanalization was defined as TICI score 2b or 3.

Results: Eighty-three patients with a median age of 86±4.34yo were compared to 126 patients with median age of 63±12.48yo (p<0.0001). Good recanalization was achieved in 74% of patients ≥80yo compared to 84% in patients <80yo (p= 0.06). Poor outcomes were reported in 74.6% of patients ≥80yo compared to 47.0% in patients <80yo (p<0.0001). All-cause mortality was 28.9% in the ≥80yo vs 12.9% in the < 80yo (p=0.006).

Conclusion: In our cohort, the clinical outcomes among octogenarians receiving MT were worse than in younger patients despite no difference in recanalization. Various factors may be responsible including overall health status, comorbid conditions and neuroplasticity. Further prospective multicentral studies are needed to better understand the benefit of MT in octogenarians.

Guidezilla Catheter in Neuroendovascular Interventions: A Case Series Study

BACKGROUND

Neuroendovascular procedures can be challenging due to severe angulation of the cervical and cranial vessels. Typical approaches for overcoming this tortuosity involve using multiple telescoping catheter systems to provide proximal support for therapeutic device delivery. Although this approach can be effective, it does have limitations.

METHODS

We describe the utility of the Guidezilla (Boston Scientific, Natick, Massachusetts, USA) guide extension catheter, a device designed for coronary interventions, in the treatment of 3 patients undergoing neuroendovascular procedures.

RESULTS

In these 3 cases, the decision to use a guide extension catheter varied but was mainly due to severe tortuosity, heavy calcifications, and failure to introduce stents into distal locations.

CONCLUSIONS

Although helpful in overcoming challenging anatomy, the Guidezilla guide extension catheter should be used with caution when used as a bailout device.

Abstract TP53: Geomagnetic Storms Do Not Predict The Occurrence Of LVO Stroke Clusters Necessitating Endovascular Intervention

Intro: Space weather induced geomagnetic storms have been associated with an increased risk of stroke occurrence. Data on image-proven, temporally related large vessel occlusion stroke (LVO) and geomagnetic storms are lacking. We sought to investigate this potential association to determine whether space weather forecasts can be used to predict incoming cluster events.

Methods: Data from a Comprehensive Stroke Center were collected from January 1, 2017, to April 15, 2022. Space weather data were downloaded from the World Data Centre for Geomagnetism, Kyoto homepage (http://wdc.kugi.kyoto-u.ac.jp/kp/index.html#LIST) The indications for mechanical endovascular reperfusion (MER) were in accordance with the Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Univariate binary logistic regression was performed to assess the potential associations between space weather data and LVO MER cases with 48 hour lag effect. Geomagnetic activity was defined by the National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Centre (SWPC) space weather scales.

Results: Of the 1931 days included in this study, there were 538 (27.86%) days with at least one LVO MER (450 (23.3%) with 1, 81 (4.19%) with 2, and 7 (0.36%) with 3. There were 1784 days without geomagnetic storm activity and 147 days with minor to severe storms. 290 MER cases occurred out 1014 days of minimal activity (28.6%) 133 MER cases out 497 days of unsettled activity (26.76%) 0.91(0.72-116), 78 MER cases out of 273 days of active activity (28.57%) 1.00(0.74-1.34), 25 MER cases out 109 days of minor storm (22.94%) 0.74(0.47-1.19) and 12 MER cases out of the 38 days of moderate to extreme storms (31.58%) 1.15(0.57-2.31) p-value 0.697.

Conclusion: There was no statistically significant association with geomagnetic storms and the occurrence of large vessel stroke interventions taking into consideration a 48 hour lag effect. Comprehensive stroke center readiness is of utmost importance, but space weather forecasts are unlikely to be helpful in predicting LVO stroke cluster events.

Abstract WMP115: Stroke Patient Cerebral Endothelial Cells And Their Exosomes Impair Cerebral Endothelial Cell Function

Background: Cerebral endothelial cells (CECs) play a key role in mediating cerebral vascular hemostasis. The biological function of CECs in stroke patients remains unknown due to technical challenges to acquire patient CECs. We isolated and analyzed the function of CECs from living stroke patients.

Methods: Cells were isolated from stent retrievers used for mechanical thrombectomy (MT) for patients with large vessel occlusion (LVO) after completion of the intervention as part of an IRB approved protocol. Patient endothelial cells (pCECs) were analyzed.

Results: We isolated 300-400 primary brain endothelial cells per retriever from 5 patients with LVO with ages ranging from 69 to 86 years. The pCECs exhibited a typical monolayer cobblestone appearance and expressed VE-cadherin, but not α-smooth muscle actin, indicating that these cells are CECs. Western blot analysis showed that compared to human primary brain microvascular endothelial cells (hBMECs, Cell System), pCECs expressed significantly increased iNOS, VEGF, and VEGFR2, but reduced eNOS and Ang1. In vitro endothelial permeability and angiogenesis assays showed that pCECs robustly increased cell leakage and angiogenesis, respectively. Moreover, treatment of healthy hBMECs with exosomes derived from patient CECs (pCEC-Exos) significantly increased cell leakage and reduced cell integrity, which were associated with the reduction of tight junction proteins ZO1 and Occludin. Blockage of the caveolin endocytotic pathway by nystatin abolished the effect of pCEC-Exos on hBMEC function.

Conclusions: Our data demonstrate that: 1) pCECs from stroke patients can be harvested; 2) pCECs are dysfunctional, and 3) pCEC-Exos induce dysfunction of healthy CECs. These data provide novel insights into the mediation of stroke-induced neurovascular dysfunction by pCECs.

Abstract 162: Arterial Aspirate Derived Exosomes From Patients With Large Vessel Occlusion Are Associated With Increased Blood-brain Barrier Permeability, Decreased Endothelial Integrity As Well Poor Clinical And Radiographic Outcomes Following Mechanical Thrombectomy

Introduction: Exosomes (~30-150nm microvessicles [MVs]), are important mediators of cell-cell communication and have been associated with injurious and neuroprotective processes in experimental stroke models. Since many patients treated with mechanical thrombectomy (MT) do not improve despite successful recanalization we hypothesized that these exosomes may mediate injurious processes leading to worse outcomes.

Methods: As part of an IRB approved protocol we analyzed arterial blood and retrieved clots aspirated during MT from patients with anterior circulation LVO. MVs were isolated and their effects on BBB permeability and endothelial monolayer integrity measured by transepithelial/endothelial electrical resistance (TEER) in cultured human endothelial cells were measured. Following adjustment for age, DM, NIHSS this effect was also correlated (Pearson R) with NIHSS, RAPID™ CTP parameters, TICI score, BP post MT, 24hr ASPECTS, ICH incidence and mRS.

Results: Forty-eight patients were enrolled; mean age was 71±14yrs, 56% were female and 20% were African-American. Mean NIHSS was 16±6.6 with a median baseline ASPECTS score of 9 (range 3-10). Baseline CTP parameters (N=21) were: infarct core 25.8±38.5cc, mismatch volume 103±72.2cc and hypoperfusion index (Tmax>10s/Tmax>6s) 0.34±0.25. Recanalization (TICI 2b/c/3) was achieved in 93.8%. The median 24hr ASPECTS was 7 (range 0-10). At last follow-up 43.5% of patients achieved a good outcome (mRS<=2). BBB permeability was associated with NIHSS change (r=-0.31, p=0.0093), TICI (r=-0.31, p=0.031), SBP post MT (r=0.41, p=0.0036) and 24hr ASPECTS (r=-0.31, p=0.015). TEER correlated most strongly with NIHSS change (r=0.36, p=0.0041), TICI (r=0.35, p=0.02), 24hr ASPECTS (r=0.37, p=0.027) and hypoperfusion index (r=-0.4, p=0.041).

Conclusions: Arterial aspirate derived MVs can be isolated from LVO stroke patients. Their effects on BBB permeability and endothelial integrity significantly correlated with clinical and radiographical markers of poor outcomes. It is therefore plausible that clot derived exosomes may impact neurological outcomes following MT through endothelial and BBB injury. In addition, these in vitro BBB measures may serve as biomarkers for post-stroke outcomes.