Association between CT Perfusion Parameters and Hemorrhagic Transformation after Endovascular Treatment in Acute Ischemic Stroke: Results from the ESCAPE-NA1 Trial

BACKGROUND AND PURPOSE

Hemorrhagic transformation can occur as a complication of endovascular treatment for acute ischemic stroke. This study aimed to determine whether ischemia depth as measured by admission CTP metrics can predict the development of hemorrhagic transformation at 24 hours.

MATERIALS AND METHODS

Patients with baseline CTP and 24-hour follow-up imaging from the ESCAPE-NA1 trial were included. RAPID software was used to generate CTP volume maps for relative CBF, CBV, and time-to-maximum at different thresholds. Hemorrhage on 24-hour imaging was classified according to the Heidelberg system, and volumes were calculated. Univariable and multivariable regression analyses assessed the association between CTP lesion volumes and hemorrhage/hemorrhage subtypes.

RESULTS

Among 408 patients with baseline CTP, 142 (35%) had hemorrhagic transformation at 24-hour follow-up, with 89 (63%) classified as hemorrhagic infarction (HI1/HI2), and 53 (37%), as parenchymal hematoma (PH1/PH2). Patients with HI or PH had larger volumes of low relative CBF and CBV at each threshold compared with those without hemorrhage. After we adjustied for baseline and treatment variables, only increased relative CBF <30% lesion volume was associated with any hemorrhage (adjusted OR, 1.14; 95% CI, 1.02-1.27 per 10 mL), as well as parenchymal hematoma (adjusted OR, 1.23; 95% CI, 1.06-1.43 per 10 mL). No significant associations were observed for hemorrhagic infarction.

CONCLUSIONS

Larger "core" volumes of relative CBF <30% were associated with an increased risk of PH following endovascular treatment. This particular metric, in conjunction with other clinical and imaging variables, may, therefore, help estimate the risk of post-endovascular treatment hemorrhagic complications.

Machine learning, deep learning and hernia surgery. Are we pushing the limits of abdominal core health? A qualitative systematic review

INTRODUCTION

This systematic review aims to evaluate the use of machine learning and artificial intelligence in hernia surgery.

METHODS

The PRISMA guidelines were followed throughout this systematic review. The ROBINS-I and Rob 2 tools were used to perform qualitative assessment of all studies included in this review. Recommendations were then summarized for the following pre-defined key items: protocol, research question, search strategy, study eligibility, data extraction, study design, risk of bias, publication bias, and statistical analysis.

RESULTS

A total of 13 articles were ultimately included for this review, describing the use of machine learning and deep learning for hernia surgery. All studies were published from 2020 to 2023. Articles varied regarding the population studied, type of machine learning or Deep Learning Model (DLM) used, and hernia type. Of the thirteen included studies, all included either inguinal, ventral, or incisional hernias. Four studies evaluated recognition of surgical steps during inguinal hernia repair videos. Two studies predicted outcomes using image-based DMLs. Seven studies developed and validated deep learning algorithms to predict outcomes and identify factors associated with postoperative complications.

CONCLUSION

The use of ML for abdominal wall reconstruction has been shown to be a promising tool for predicting outcomes and identifying factors that could lead to postoperative complications.

Sex differences in acute stroke metrics and outcome dependent on COVID status

BACKGROUND AND PURPOSE

Biological sex is known to have an impact on quality metrics of acute stroke. We aimed to determine whether COVID positivity accentuates this effect and constitutes worse outcome.

METHODS

The present analysis was based on the Global COVID-19 Stroke Registry, a retrospective, international, cohort study of consecutive ischemic stroke patients receiving intravenous thrombolysis and/or endovascular thrombectomy between 1 March 2020 and 30 June 2021. We investigated differences between the sexes in patient characteristics, acute stroke metrics as well as post-stroke outcome in COVID-positive and COVID-negative stroke patients undergoing acute revascularization procedures.

RESULTS

A total of 15,128 patients from 106 centers were recorded in the Global COVID-19 Stroke Registry, 853 (5.6%) of whom were COVID-positive. Overall, COVID-positive individuals were treated significantly slower according to every acute stroke metric compared to COVID-negative patients. We were able to show that key quality indicators in acute stroke treatment were unfavorable for COVID-negative women compared to men (last-seen-well-to-door time + 11 min in women). Furthermore, COVID-negative women had worse 3-month outcomes (3-month modified Rankin Scale score [interquartile range] 3.0 [4.0] vs. 2.0 [3.0]; p < 0.01), even after adjusting for confounders. In COVID-positive individuals no such difference between the sexes, either in acute management metrics or in 3-month outcome, was seen.

CONCLUSION

Known sex-related differences in acute stroke management exist and extend to times of crisis. Nevertheless, if patients were COVID-19-positive at stroke onset, women and men were treated the same, which could be attributed to structured treatment pathways.

Influence of Infarct Morphology and Patterns on Cognitive Outcomes After Endovascular Thrombectomy

BACKGROUND

To assess the association of qualitative and quantitative infarct characteristics and 3 cognitive outcome tests, namely the Montreal Cognitive Assessment (MOCA) for mild cognitive impairment, the Boston Naming Test for visual confrontation naming, and the Sunnybrook Neglect Assessment Procedure for neglect, in large vessel occlusion stroke.

METHODS

Secondary observational cohort study using data from the randomized-controlled ESCAPE-NA1 trial (Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke), in which patients with large vessel occlusion undergoing endovascular treatment were randomized to receive either intravenous Nerinetide or placebo. MOCA, Sunnybrook Neglect Assessment Procedure, and 15-item Boston Naming Test were obtained at 90 days. Total infarct volume, gray matter, and white matter infarct volumes were manually measured on 24-hour follow-up imaging. Infarcts were also visually classified as either involving the gray matter only or both the gray and white matter and scattered versus territorial. Associations of infarct variables and cognitive outcomes were analyzed using multivariable ordinal or binary logistic regression models.

RESULTS

Of 1105 patients enrolled in ESCAPE-NA1, 1026 patients with visible infarcts on 24-hour follow-up imaging were included. MOCA and Sunnybrook Neglect Assessment Procedure were available for 706 (68.8%) patients and the 15-item Boston Naming Test was available for 682 (66.5%) patients. Total infarct volume was associated with worse MOCA scores (adjusted common odds ratio per 10 mL increase, 1.05 [95% CI, 1.04-1.06]). After adjusting for baseline variables and total infarct volume, mixed gray and white matter involvement (versus gray matter-only adjusted common odds ratio, 1.92 [95% CI, 1.37-2.69]), white matter infarct volume (adjusted common odds ratio per 10 mL increase 1.36 [95% CI, 1.18-1.58]) and territorial (versus scattered) infarct pattern (adjusted common odds ratio, 1.65 [95% CI, 1.15-2.38]) were associated with worse MOCA scores. Results for Sunnybrook Neglect Assessment Procedure and 15-item Boston Naming Test were similar, except for the territorial infarct pattern, which did not reach statistical significance in multivariable analysis.

CONCLUSIONS

Besides total infarct volume, infarcts that involve the white matter and that show a territorial distribution were associated with worse cognitive outcomes, even after adjusting for total infarct volume.

Outcomes after Perioperative Transient Ischemic Attack Following Cardiac Surgery

Perioperative transient ischemic attacks (PTIAs) are associated with significantly increased rates of postoperative complications such as low cardiac output, atrial fibrillation, and significantly higher mortality in cardiac procedures. The current literature on PTIAs is sparse and understudied. Therefore, we aim to understand the effects of PTIA on hospital utilization, readmission, and morbidity. Using data on all the cardiac procedures at the University of Pittsburgh Medical Center from 2011 to 2019, fine and gray analysis was performed to identify whether PTIAs and covariables correlate with increased hospital utilization, stroke, all-cause readmission, Major Adverse Cardiac and Cerebrovascular Events (MACCE), MI, and all-cause mortality. Logistic regression for longer hospitalization showed that PTIA (HR: 2.199 [95% CI: 1.416-3.416] increased utilization rates. Fine and gray modeling indicated that PTIA (HR: 1.444 [95% CI: 1.096-1.902], p < 0.01) increased the rates of follow-up all-cause readmission. However, PTIA (HR: 1.643 [95% CI: 0.913-2.956] was not statistically significant for stroke readmission modeling. Multivariate modeling for MACCE events within 30 days of surgery (HR: 0.524 [95% CI: 0.171-1.605], p > 0.25) and anytime during the follow-up period (HR: 1.116 [95% CI: 0.825-1.509], p > 0.45) showed no significant correlation with PTIA. As a result of PTIA's significant burden on the healthcare system due to increased utilization, it is critical to better define and recognize PTIA for timely management to improve perioperative outcomes.

CT Perfusion Does Not Modify the Effect of Reperfusion in Patients with Acute Ischemic Stroke Undergoing Endovascular Treatment in the ESCAPE-NA1 Trial

BACKGROUND AND PURPOSE

Although reperfusion is associated with improved outcomes in patients with acute ischemic stroke undergoing endovascular treatment, many patients still do poorly. We investigated whether CTP modifies the effect of near-complete reperfusion on clinical outcomes, ie, whether poor clinical outcomes despite near-complete reperfusion can be partly or fully explained by CTP findings.

MATERIALS AND METHODS

Data are from the Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) trial. Admission CTP was processed using RAPID software, generating relative CBF and CBV volume maps at standard thresholds. CTP lesion volumes were compared in patients with-versus-without near-complete reperfusion. Associations between each CTP metric and clinical outcome (90-day mRS) were tested using multivariable logistic regression, adjusted for baseline imaging and clinical variables. Treatment-effect modification was assessed by introducing CTP lesion volume × reperfusion interaction terms in the models.

RESULTS

CTP lesion volumes and reperfusion status were available in 410/1105 patients. CTP lesion volumes were overall larger in patients without near-complete reperfusion, albeit not always statistically significant. Increased CBF <34%, CBV <34%, CBV <38%, and CBV <42% lesion volumes were associated with worse clinical outcome (ordinal mRS) at 90 days. CTP core lesion volumes did not modify the treatment effect of near-complete recanalization on clinical outcome.

CONCLUSIONS

CTP did not modify the effect of near-complete reperfusion on clinical outcomes. Thus, CTP cannot explain why some patients with near-complete reperfusion have poor clinical outcomes.

Mediation of Successful Reperfusion Effect through Infarct Growth and Cerebral Edema: A Pooled, Patient-Level Analysis of EXTEND-IA Trials and SELECT Prospective Cohort

OBJECTIVE

Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship.

METHODS

In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift.

RESULTS

A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (β = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results.

INTERPRETATION

In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023.

RESCUE BT 2, a multicenter, randomized, double-blind, double-dummy trial of intravenous tirofiban in acute ischemic stroke: study rationale and design

BACKGROUND

Tirofiban is a glycoprotein IIb/IIIa receptor inhibitor that has been shown to be effective in the treatment of acute coronary syndromes. However, it remains unknown whether it improves outcomes in patients with acute ischemic stroke.

OBJECTIVE

This trial investigates the efficacy and safety of tirofiban compared with aspirin for acute ischemic stroke within 24 hours after symptom onset.

METHODS AND DESIGN

The Efficacy and Safety of Tirofiban Compared with Aspirin in the Treatment of Acute Ischemic Stroke (RESCUE BT 2) Trial is an investigator-initiated, prospective, randomized, double-blind, double-dummy, multicenter clinical trial. Up to 1158 eligible patients will be consecutively randomized to receive antiplatelet therapy with tirofiban or aspirin in 1:1 ratio across approximately 100 stroke centers in China.

OUTCOMES

The primary endpoint is the proportion of patients with excellent functional outcome defined as modified Rankin scale score of 0 to 1 at 90 days after randomization. Lead safety endpoints include symptomatic intracerebral hemorrhage at 48 hours and mortality at 90 days. Trial registry number: ChiCTR2000029502 (www.chictr.org.cn).

Interventional compared with medical management of symptomatic carotid web: A systematic review

BACKGROUND

Carotid web (CaW) is non-atheromatous, shelf-like intraluminal projection, generally affecting the posterolateral wall of the proximal internal carotid artery, and associated with embolic stroke, particularly in younger patients without traditional stroke risk factors. Treatment options for symptomatic CaWs include interventional therapy with carotid endarterectomy or carotid stenting versus medical therapy with antiplatelet or anticoagulants. As safety and efficacy of these approaches have been incompletely delineated in small-to-moderate case series, we performed a systematic review of outcomes with interventional and medical management.

METHODS

Systematic literature search was conducted and data analyzed per PRISMA guidelines (Preferred Reporting Items for Systemic Reviews and Meta-Analyses) from January 2000 to October 2021 using the search strategy: "Carotid web" OR "Carotid shelf" OR "Web vessels" OR "Intraluminal web". Patient-level demographics, stroke risk factors, technical procedure details, medical and interventional management strategies were abstracted across 15 series. All data were analyzed using descriptive statistics.

RESULTS

Among a total of symptomatic 282 CaW patients across 14 series, age was 49.5 (44-55.7) years, 61.7% were women, and 76.6% were black. Traditional stroke risk factors were less frequent than the other stroke causes, including hypertension in 28.6%, hyperlipidemia 14.6%, DM 7.0%, and smoking 19.8%. Thrombus adherent to CaW was detected on initial imaging in 16.2%. Among 289 symptomatic CaWs across 15 series, interventional management was pursued in 151 (52.2%), carotid artery stenting in 87, and carotid endarterectomy in 64; medical management was pursued in 138 (47.8%), including antiplatelet therapy in 80.4% and anticoagulants in 11.6%. Interventional and medical patients were similar in baseline characteristics. The reported time from index stroke to carotid revascularization was median 14 days (IQR 9.5-44). In the interventional group, no periprocedural mortality was noted, major periprocedural complications occurred in 1/151 (0.5%), and no recurrent ischemic events were observed over follow-up range of 3-60 months. In the medical group, over a follow-up of 2-55 months, the recurrence cerebral ischemia rate was 26.8%.

CONCLUSION

Cumulative evidence from multiple series suggests that carotid revascularization is a safe and effective option for preventing recurrent ischemic events in patients with symptomatic carotid webs.

Clinical Results of the Advanced Neurovascular Access Catheter System Combined With a Stent Retriever in Acute Ischemic Stroke (SOLONDA)

BACKGROUND

The Advanced Neurovascular Access (ANA) thrombectomy system is a novel stroke thrombectomy device comprising a self-expanding funnel designed to reduce clot fragmentation by locally restricting flow while becoming as wide as the lodging artery. Once deployed, the ANA device allows distal aspiration combined with a stent retriever to mobilize the clot into the funnel where it remains copped during extraction. We investigated the safety and efficacy of ANA catheter system.

METHODS

SOLONDA (Solitaire in Combination With the ANA Catheter System as Manufactured by Anaconda) was a prospective, open, single-arm, multicenter trial with blinded assessment of the primary outcome by an independent core lab. Patients with anterior circulation vessel occlusion admitted within 8 hours from symptom onset were eligible. The primary end point was successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b-3) with ≤3 passes of the ANA device in combination with stent retriever, before the use of rescue therapy in the intention to treat population. Primary predefined analysis was noninferiority as compared to the performance end point observed in HERMES (High Effective Reperfusion Using Multiple Endovascular Devices).

RESULTS

After enrollment of 74 patients, an interim analysis was conducted, and the trial Steering Committee decided to terminate recruitment due to safety and performance objectives were reached. Mean age was 71.6 (SD 8.9) years, 46.6% women and median National Institutes of Health Stroke Scale on admission 14 (interquartile range, 10-19). Successful reperfusion within 3 passes before rescue therapy was achieved in 60/72 (83.3% [95% CI, 74.7%-91.9%]) with a rate of complete reperfusion (modified Thrombolysis in Cerebral Infarction score 2c-3) of 60% (95% CI, 48.4%-71.1%; 43/72 patients). After noninferiority was confirmed (P<0.01), the ANA device also showed superiority in the rate of successful reperfusion with ≤3 passes (P=0.02). First-pass successful recanalization rate was 55.6% (95% CI, 44.1%-67.0%), with a first-pass complete recanalization rate of 38.9% (95% CI, 27.6%-50.1%). Rescue therapy to obtain a modified Thrombolysis in Cerebral Infarction score 2b-3 was needed in 12/72 (17%) patients. At 90 days, the rate of favorable functional outcome (modified Rankin Scale score 0-2) was 57.5% (95% CI, 46.2%-68.9%), and the rate of excellent functional outcome (modified Rankin Scale score 0-1) was 45.2% (95% CI, 33.8%-56.6%). The rate of severe adverse device related was 1.4%.

CONCLUSIONS

In this clinical experience, the ANA device achieved a high rate of complete recanalization with a preliminary good safety profile and favorable 90 days clinical outcomes.

Endovascular treatment for acute Basilar Artery Occlusion - a multicenter randomized controlled trial (ATTENTION)

BACKGROUND AND HYPOTHESIS

Recently, two multicenter randomized controlled trials (RCT) failed to show a significantly beneficial effect of endovascular treatment (EVT) in patients with acute basilar artery occlusion (BAO). However, both trials suffered from equipoise issues which may have hindered the validity of the trial results. Therefore, additional RCT studies are needed to explore the potential benefit of EVT in patients presenting with BAO.

STUDY DESIGN

ATTENTION is an investigator-initiated, multicenter, prospective, randomized, controlled clinical trial with open-label treatment and blinded outcome assessment (PROBE) of EVT versus best medical management (BMM). The primary effect parameter is a modified Rankin Score of 0-3 at day 90.

DISCUSSION

ATTENTION will provide evidence for the efficacy and safety of EVT in stroke patients within 12 hours after BAO.

Prestroke Disability and Outcome After Thrombectomy for Emergent Anterior Circulation Large Vessel Occlusion Stroke

BACKGROUND AND OBJECTIVES

To determine the impact of endovascular therapy for large vessel occlusion stroke in patients with vs those without premorbid disability.

METHODS

We performed a post hoc analysis of the TREVO Stent-Retriever Acute Stroke (TRACK) Registry, which collected data on 634 consecutive patients with stroke treated with the Trevo device as first-line endovascular thrombectomy (EVT) at 23 centers in the United States. We included patients with internal carotid or middle cerebral (M1/M2 segment) artery occlusions, and the study exposure was patient- or caregiver-reported premorbid modified Rank Scale (mRS) score ≥2 (premorbid disability [PD]) vs premorbid mRS score of 0 to 1 (no PD [NPD]). The primary outcome was no accumulated disability, defined as no increase in 90-day mRS score from the patient's premorbid mRS score.

RESULTS

Of the 634 patients in TRACK, 407 patients were included in our cohort, of whom 53 (13.0%) had PD. The primary outcome of no accumulated disability was achieved in 37.7% (20 of 53) of patients with PD and 16.7% (59 of 354) of patients with NPD (p < 0.001), while death occurred in 39.6% (21 of 53) and 14.1% (50 of 354) (p < 0.001), respectively. The adjusted odds ratio of no accumulated disability for patients with PD was 5.2 (95% confidence interval [CI] 2.4-11.4, p < 0.001) compared to patients with NPD. However, the adjusted odds ratio for death in patients with PD was 2.90 (95% CI 1.38-6.09, p = 0.005).

DISCUSSION

In this study of patients with anterior circulation acute ischemic stroke treated with EVT, we found that PD was associated with a higher probability of not accumulating further disability compared to patients with NPD but also with higher probability of death.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in anterior circulation acute ischemic stroke treated with EVT, patients with PD compared to those without disability were more likely not to accumulate more disability but were more likely to die.

Strength of Association between Infarct Volume and Clinical Outcome Depends on the Magnitude of Infarct Size: Results from the ESCAPE-NA1 Trial

BACKGROUND AND PURPOSE

Infarct volume is an important predictor of clinical outcome in acute stroke. We hypothesized that the association of infarct volume and clinical outcome changes with the magnitude of infarct size.

MATERIALS AND METHODS

Data were derived from the Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) trial, in which patients with acute stroke with large-vessel occlusion were randomized to endovascular treatment plus either nerinetide or a placebo. Infarct volume was manually segmented on 24-hour noncontrast CT or DWI. The relationship between infarct volume and good outcome, defined as mRS 0-2 at 90 days, was plotted. Patients were categorized on the basis of visual grouping at the curve shoulders of the infarct volume/outcome plot. The relationship between infarct volume and adjusted probability of good outcome was fitted with linear or polynomial functions as appropriate in each group.

RESULTS

We included 1099 individuals in the study. Median infarct volume at 24 hours was 24.9 mL (interquartile range [IQR] = 6.6-92.2 mL). On the basis of the infarct volume/outcome plot, 4 infarct volume groups were defined (IQR = 0-15 mL, 15.1-70 mL, 70.1-200 mL, >200 mL). Proportions of good outcome in the 4 groups were 359/431 (83.3%), 219/337 (65.0%), 71/201 (35.3%), and 16/130 (12.3%), respectively. In small infarcts (IQR = 0-15 mL), no relationship with outcome was appreciated. In patients with intermediate infarct volume (IQR = 15-200 mL), there was progressive importance of volume as an outcome predictor. In infarcts of > 200 mL, outcomes were overall poor.

CONCLUSIONS

The relationship between infarct volume and clinical outcome varies nonlinearly with the magnitude of infarct size. Infarct volume was linearly associated with decreased chances of achieving good outcome in patients with moderate-to-large infarcts, but not in those with small infarcts. In very large infarcts, a near-deterministic association with poor outcome was seen.

Abstract P524: Impact of Intra-Procedural Workflow and Time Metrics of Establishing Fast Reperfusion on Clinical Outcomes in the ESCAPE-NA1 Trial

Background: Time from imaging to establishing reperfusion is a major influencer of clinical outcomes and over the years thrombectomy techniques have evolved rapidly. This has led to improvements in achieving fast and complete reperfusion. We analyzed the impact of various intra-procedural techniques and tools on the speed of reperfusion and correlated procedural duration with probability of achieving good clinical outcomes.

Methods: We analyzed intra-procedural time metrics and examined factors leading to delays during EVT. The relationship between outcome (mRS Scale) and procedural time from arterial puncture to time of achieving mTICI 2b-3 First Reperfusion (FRE) was modeled using logistic regression.

Results: The various procedural time metrics are summarized in Figure 1. Every 10-minute increase in FRE time reduced the probability of achieving functional independence(90-day modified Rankin Scale 0-2) by 6.7% (P=0.021, adjusted). The medianFRE timewas 25min (IQR 17-39) and was significantly longer in patients with tandem occlusions(median 34min, p 0.0005). General anesthesia vs procedural sedation vs no sedation use did not significantly alter the FRE time (p = 0.1453). The use of BGC (54.2%) was nominally longer FRE (median 26min “IQR 18-38” vs 23ming, “IQR 16-38”; p 0.095)while the use of contact aspiration (n=213) vs retrievable stents (n=676) as the first approach was associated with a shorter FRE time (21min “IQR 14-35” vs 26 min “IQR18-40”, p =0.001).

Conclusions: Puncture to first reperfusion time is a significant predictor of clinical outcome in theESCAPE-NA1 trial. Various procedural and anatomical factors influence this timemetric.

Figure: Intra-Procedural workflow time metrics expressed in medians and 90th percentiles. The cumulative times are calculated for each major milestone in the procedure for upto three attempts. First reperfusion duration where TICI 2b was achieved is shown in comparison to other procedural time metrics.

Abstract P536: Impact of the Covid-19 Pandemic on the Volumes and Outcomes of Acute Ischemic Stroke and Myocardial Infarction

Introduction: The COVID-19 pandemic has wreaked havoc on the presentation, care and outcomes of patients with acute cerebrovascular and cardiovascular conditions. We sought to measure the national impact of COVID-19 on the care for acute ischemic stroke (AIS) and acute myocardial infarction (AMI).

Methods: In this retrospective, observational study, we used the Premier Healthcare Database to evaluate the changes in the volume of care and hospital outcomes for AIS and AMI in relation to the pandemic. The pandemic months were defined from March 1, 2020- April 30, 2020 and compared to the same period in the year prior. Outcome measures were volumes of hospitalization and reperfusion treatment for AIS and AMI (including intravenous thrombolysis [IVT] and/or mechanical thrombectomy [MT] for AIS and percutaneous coronary interventions [PCI] for AMI) as well as in-hospital mortality, hospital length of stay (LOS) and hospitalization costs were compared across a 2-month period at the height of the pandemic versus the corresponding period in the prior year.

Results: There were 95,453 AIS patients across 145 hospitals and 19,744 AMI patients across 126 hospitals. There was a significant nation-wide decline in the absolute number of hospitalizations for AIS (-38.94%;95%CI,-34.75% to -40.71%) and AMI (-38.90%;95%CI,-37.03% to -40.81%) as well as IVT (-30.32%;95%CI,-27.02% to -33.83%), MT (-23.54%;95%CI,-19.84% to -27.70%), and PCI (-35.05%;95%CI,-33.04% to -37.12%) during the first two months of the pandemic. This occurred across low-, mid-, and high-volume centers and in all geographic regions. Higher in-hospital mortality was observed in AIS patients (5.7% vs.4.2%, p=0.0037;OR 1.41,95%CI 1.1-1.8) but not

AMI patients. A shift towards an increase in the proportion of admitted AIS and AMI patients receiving reperfusion therapies suggests a greater clinical severity among patients that were hospitalized for these conditions during the pandemic. A shorter length of stay (AIS: -17%, AMI: -20%), and decreased hospitalization costs (AIS: -12%, AMI: -19%) were observed.

Conclusions: Our findings shed light on the combined health outcomes and economic impact the COVID-19 pandemic has had on acute stroke and cardiac emergency care.

Abstract P467: Clinical Effectiveness of Endovascular Stroke Treatment in the Early and Extended Time Windows

Background and Purpose: The clinical efficacy of mechanical thrombectomy (MT) has been unequivocally demonstrated in multiple randomized clinical trials (RCTs). However, these studies were performed in carefully selected centers and utilized strict inclusion criteria. We aim to assess the clinical effectiveness of MT by comparing the specific RCT populations with corresponding patient cohorts derived from a prospective registry.

Methods: A total of 2008 patients from 76 sites across 12 countries were enrolled in a prospective open-label MT registry. Patients were categorized into the corresponding cohorts of the SWIFT-Prime, DAWN, and DEFUSE 3 trials based on the age, baseline NIHSS, occlusion site, IV tPA use, pre-morbid mRS and time to treatment criteria used in the RCTs without considering specific parenchymal imaging findings. Baseline and outcome variables were compared across the corresponding groups.

Results: As compared to the treated patients in the actual trials, registry-derived patients tended to be younger and had lower baseline ASPECTS. In addition, time to treatment was earlier and the use of IV tPA and general anesthesia were higher in DAWN- and DEFUSE 3-registry derived patients versus their corresponding trials. Reperfusion rates were higher in the registry patients. The rates of 90-day good outcome (mRS 0-2) in registry-derived patients were comparable to those of the patients treated in the corresponding RCTs (SWIFT-Prime, 64.5% vs 60.2%; DAWN, 50.4% vs 48.6%; Beyond-DAWN: 52.4% vs 48.6%; DEFUSE 3, 52% vs 44.6%, respectively; all P>0.05). Registry-derived patients had significant less disability than the corresponding RCT controls (ordinal mRS shift OR, P <0.05 for all).

Conclusion: Our study provides favorable generalizability data for the safety and efficacy of thrombectomy in the “real-world” setting and supports that patients may be safely treated outside the constraints of RCTs and strict guidelines.

Abstract P496: Clot Characteristics in Mechanical Thrombectomy: Interim Analysis of the EXCELLENT Registry

Introduction: Red blood cell (RBC) rich vs fibrin rich clots have different mechanical properties and greater knowledge about clot composition in the context of clinical, imaging, and procedural factors in mechanical thrombectomy (MT) may help with procedural optimization. The EXCELLENT Registry (NCT03685578) is a prospective, global, multi-center, observational registry of EmboTrap as the first line MT device for large vessel occlusion (LVO). We present an interim analysis of clot collected per pass in the registry.

Methods: Five hundred thirty-three clot specimens from 376 subjects were collected by 20 sites and sent for analysis by independent Central Labs under standardized protocol. Analysis was interrupted by COVID-19, but the labs were fully operational as of June 2020 and on track to deliver results for 300 subjects in Q4. At the time of abstract submission, composition data for 234 clots from 163 subjects was available. All available data will be presented at the time of the conference.

Results: Cardioembolic etiology (n=100) was associated with lower RBC (40.2 vs 47.2%) and higher fibrin content (31.7 vs 26.7%) compared to large artery disease (n=12). Hyperdense/vessel susceptibility sign (78+, 24-, per independent imaging core lab) corresponded to higher mean RBC content (44.4 vs 34.9%). Treatment with IV tPA (60+, 91-) had no clear impact on clot composition (42.3 vs 40.6% RBC; 30.4 vs 30.0% fibrin). Notably, clots retrieved with the first 2 passes of were more RBC rich (42.1 vs 28.0%) and clots retrieved in higher passes had a higher average fibrin content (35.5 vs 29.6%) suggesting that higher fibrin content leads to greater refractoriness.

Conclusions: Clot density/susceptibility on baseline imaging, stroke etiology and number of thrombectomy passes were associated with differential clot composition. These findings may have potential implications for the development of better MT strategies.

Abstract 42: Epidemiological Surveillance of the Impact of the Covid-19 Pandemic on Stroke Care Using Artificial Intelligence

Background: The degree to which the 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 (AI) platform.

Methods: Data were derived from the Viz Platform, an AI application designed to optimize the workflow of acute stroke patients. Neuroimaging data on suspected stroke patients 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 CTA, CTP, Large vessel occlusions (LVOs) (defined according to the automated software detection), and severe strokes on CTP (defined as those with hypoperfusion volumes>70mL) normalized as number of patients per day per hospital. Data from the pre-pandemic (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 LVO on CTA and severe strokes on CTP were 11.2%(n=2,602) and 14.7%(n=1,229/8,328), respectively. There were significant declines in the overall number of CTAs (-22.8%;1.39 to 1.07 patients/day/hospital,p<0.001) and CTPs (-26.1%;0.50 to 0.37 patients/day/hospital,p<0.001) as well as in the incidence of LVO (-17.1%;0.15 to 0.13 patients/day/hospital,p<0.001) and severe strokes on CTP (-16.7%;0.12 to 0.10 patients/day/hospital, p<0.005). The sampled cohort showed similar declines in the rates of LVOs versus thrombectomy (18.8%vs.19.5%, p=0.9) and CSC hospitalizations (18.8%vs.11.0%, p=0.4).

Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This underscores the broader application of AI neuroimaging platforms for the real-time monitoring of stroke systems of care.

Abstract 45: Global Impact of the Covid-19 Pandemic on Stroke Hospitalizations and Mechanical Thrombectomy Volumes: A Society of Vascular and Interventional Neurology Covid-19 International Collaboration

Introduction: The COVID-19 pandemic led to profound changes in both the organization of health care systems and the psychosocial behavior of the population worldwide. The extent to which the COVID-19 outbreak disrupted stroke systems of care merits study from a global lens.

Methods: We conducted a retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The study objectives were to measure the global impact of the pandemic on the volumes for mechanical thrombectomy (MT), stroke and intracranial hemorrhage (ICH) hospitalizations over a 3-month period at the height of the pandemic (March 1 to May 31, 2020) compared with two control 3-month periods prior (immediately preceding and one year prior). A secondary objective was to examine whether these changes in volume were impacted by COVID-19 and baseline hospital center stroke volumes. Third, we evaluated the relationships between stroke and COVID-19 diagnoses.

Results: There were 26,699 stroke admissions in the 3 months immediately before compared to 21,576 admissions during the pandemic months, representing a 19.2% (95%CI,-19.7 to -18.7) decline. There were 5,191 MT procedures in the 3 months preceding compared to 4,533 procedures during the pandemic, representing a 12.7% (95%CI,-13.6 to -11.8) drop. Significant reductions were also seen in relation to the prior year control period. The decreases were noted across centers with high, intermediate, and low COVID-19 hospitalization burden, and also across high, intermediate, and low volume stroke centers. High-volume COVID-19 centers (-20.5%) had greater declines in MT volumes than mid- (-10.1%) and low-volume (-8.7%) centers. 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.

Conclusions: The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, MT procedures, ischemic stroke/TIA and ICH admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke and MT volumes. Centers with higher COVID-19 inpatient volumes experienced steeper declines.

Clinical outcomes of isolated deep grey matter infarcts after endovascular treatment of large vessel occlusion stroke

PURPOSE

There are few data on the prevalence and impact of isolated deep grey matter infarction in acute stroke. In this study, we aimed to investigate the prevalence of isolated deep grey matter infarcts and their impact on the outcome.

METHODS

Infarcts on 24-h follow-up imaging (non-contrast head CT or diffusion-weighted MRI) in the ESCAPE-NA1 trial were categorized into predominantly deep grey matter infarcts vs. infarcts involving additional territories ("other infarcts"). Total infarct volume was manually segmented. Baseline characteristics and proportions of good outcome (primary outcome, defined as modified Rankin Score [mRS] 0-2 at 90 days), excellent outcome (mRS 0-1) and mortality were compared between patients with and without predominantly deep grey matter infarcts. Multivariable logistic regression with adjustment for baseline variables and total infarct volume was used to determine a possible association of predominantly deep grey matter infarcts and clinical outcome.

RESULTS

Predominantly deep grey matter infarcts were seen in 316/1026 patients (30.8%). Compared to other patients, their ASPECTS was higher, collateral status and reperfusion quality were better and time to treatment was shorter. Good outcome was seen in 239/316 (75.6%) with vs. 374/704 (53.1%) without predominantly deep grey matter infarcts. After adjusting for baseline variables and total infarct volume, predominantly deep grey matter infarcts were independently associated with excellent outcome (_adjOR: 1.45 [CI₉₅: 1.04-2.02]), but not with good outcome (_adjOR: 1.24 [CI₉₅: 0.86-1.80]) or mortality (_adjOR: 0.73 [CI₉₅:0.39-1.35]) CONCLUSION: Predominantly deep grey matter infarct patterns were seen in 1/3rd of patients and were significantly associated with increased chances of excellent outcome, independent of patient baseline status and infarct size.

Stroke etiologies in patients with COVID-19: the SVIN COVID-19 multinational registry

BACKGROUND AND PURPOSE

Coronavirus disease 2019 (COVID-19) is associated with a small but clinically significant risk of stroke, the cause of which is frequently cryptogenic. In a large multinational cohort of consecutive COVID-19 patients with stroke, we evaluated clinical predictors of cryptogenic stroke, short-term functional outcomes and in-hospital mortality among patients according to stroke etiology.

METHODS

We explored clinical characteristics and short-term outcomes of consecutively evaluated patients 18 years of age or older with acute ischemic stroke (AIS) and laboratory-confirmed COVID-19 from 31 hospitals in 4 countries (3/1/20-6/16/20).

RESULTS

Of the 14.483 laboratory-confirmed patients with COVID-19, 156 (1.1%) were diagnosed with AIS. Sixty-one (39.4%) were female, 84 (67.2%) white, and 88 (61.5%) were between 60 and 79 years of age. The most frequently reported etiology of AIS was cryptogenic (55/129, 42.6%), which was associated with significantly higher white blood cell count, c-reactive protein, and D-dimer levels than non-cryptogenic AIS patients (p

CONCLUSIONS

Our findings suggest that cryptogenic stroke among COVID-19 patients carries a significant risk of early mortality.

Collapse

Key Words

• COVID-19
• Coronavirus
• Cryptogenic
• Mortality
• Stroke

Collapse

MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Brain Ischemia
• COVID-19/blood
• COVID-19/complications
• COVID-19/diagnostic imaging
• COVID-19/mortality
• Cohort Studies
• Computed Tomography Angiography
• Egypt/epidemiology
• Female
• Fibrin Fibrinogen Degradation Products/metabolism
• Hospital Mortality
• Humans
• Ischemic Stroke/blood
• Ischemic Stroke/diagnostic imaging
• Ischemic Stroke/mortality
• Ischemic Stroke/virology
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Registries
• Retrospective Studies
• Risk Factors
• SARS-CoV-2
• Spain/epidemiology
• Stroke
• United States/epidemiology

Collapse

Grants Collapse