Endovascular Thrombectomy for Acute Ischemic Strokes: Current US Access Paradigms and Optimization Methodology

Geographic Access to High-Volume Mechanical Thrombectomy Centers in Florida, 2019

Background and Objectives

Mechanical thrombectomy (MT) improves outcomes for acute ischemic stroke (AIS) due to large vessel occlusion, but is time sensitive and requires specialized infrastructure. Professional organizations and certification bodies have promulgated minimum procedural volume standards for centers and for individual proceduralists but it is unclear whether enforcing these requirements would decrease geographic access to MT. Therefore, we sought to evaluate the potential impact of applying a minimum procedural volume threshold on geographic access to MT.

Methods

We identified all hospital discharges for stroke where an MT procedure was performed at any nonfederal hospital in Florida in 2019 using statewide hospital discharge data. We then generated geographic service area maps based on prespecified ground transport distances for the subset of hospitals that performed at least 1 MT and for those that performed at least 15 MTs that year, the minimum volume threshold required for thrombectomy capable and comprehensive stroke centers by the Joint Commission. Then, using zip code centroids and patient-level discharge hospital data, we computed the proportion of patients with AIS who lived within each of the generated service areas.

Results

A total of 105 of 297 hospitals performed MT; of those, 51 (17%) were low-volume centers (1-14 MTs/year) and 54 (18%) were high-volume centers (≥15 MTs/year). High-volume centers accounted for nearly 95% of all MTs performed in the state. Most patients hospitalized with AIS (87%) lived within 20 miles (or an estimated as a 1-hour driving time) of a hospital that performed at least 1 MT, and all (100%) lived within 115 miles (or estimated as 3-hour driving time). Setting a minimum MT volume threshold of 15 would decrease the proportion of stroke patients living within 1-hour driving time of an MT center from 87% to 77%.

Discussion

In 2019, most Florida stroke patients lived within a 1-hour ground transport time to a center that performed at least 1 MT and all lived within 3-hour driving time of an MT center, irrespective of whether a minimum procedural volume threshold of 15 cases per year was applied or not.

Effects of Social Determinants of Health on Acute Stroke Care Among Patients With Acute Ischemic Stroke: A Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

Social determinants of health (SDOH) are important contributors to poor stroke-related outcomes. While some have suggested that this association is driven by the increased incidence of stroke observed with poor SDOH, others have raised concerns regarding disparities in acute stroke care. This study aimed to determine the association between SDOH and the administration of thrombolytic therapy and mechanical thrombectomy among patients with acute ischemic stroke.

METHODS

A retrospective cohort analysis was conducted using Texas Emergency Department Public Use Data (2016-2019), including adult patients diagnosed with acute ischemic stroke. The risk ratios (RRs) of administering thrombolysis and thrombectomy based on variables representing SDOH and a collective measure (Social Vulnerability Index [SVI]) were computed using mixed-effects Poisson regression models accounting for the nested nature of patients in hospitals and neighborhoods. The Charlson comorbidity score was considered as a covariate.

RESULTS

Of the 139,852 patients with ischemic stroke (female, 51.7%; White, 67.2%; Black, 16.6%; Hispanic, 25.1%), 16,831 (12.3%) received thrombolytic therapy and 5,951 (4.3%) received mechanical thrombectomy. Age older than 65 years (RR 0.578 [0.537-0.621]) vs 18-45 years, Black (RR 0.801 [0.761-0.844]) vs White, Hispanic (RR 0.936 [0.895-0.98]) vs non-Hispanic, Medicare/Medicaid/Veterans Affairs (VA) (RR 0.917 [0.882-0.954]) or uninsured (RR 0.883 [0.833-0.935]) vs private insurance, and rural (RR 0.782 [0.723-0.845]) vs urban dwelling were less likely to be associated with thrombolysis. Patients in the highest quintile based on the SVI were less likely to receive thrombolysis than those in the lowest quintile (RR 0.926 [0.867-0.989]). Patients were less likely to receive thrombectomy if they were 65 years and older (RR 0.787 [0.691-0.895]), belonged to the Black race (RR 0.745 [0.679-0.818]) or Hispanic ethnicity (RR 0.919 [0.851-0.992]), had Medicare/Medicaid/VA insurance (RR 0.909 [0.851-0.971]), or were from a rural area (RR 0.909 [0.851-0.971]). Similarly, SVI decreased the likelihood of undergoing mechanical thrombectomy (RR 0.842 [0.747-0.95]).

DISCUSSION

Despite many improvements in stroke management, SDOH continue to be a significant driver of treatment access for acute ischemic stroke. While our findings are limited to Texas, our results should raise awareness and promote more studies regarding the effects of these SDOH at the national and international levels.

Trends in performance of thrombectomy for acute ischemic stroke patients in teaching and non-teaching hospitals

OBJECTIVES

The value of thrombectomy in patients with acute ischemic stroke cannot be understated. As such, whether these patients get access to this treatment can significantly impact their disease outcomes. We analyzed the trends in thrombectomy adoption between teaching and non-teaching hospitals in the United States, and their impact on overall patient care.

MATERIALS AND METHODS

We conducted a retrospective analysis of hospital admissions in the Nationwide Inpatient Sample with a diagnosis of acute ischemic stroke between 2012 and 2020. We compared the annual total number and proportion of patients undergoing thrombectomy between teaching and non-teaching hospitals, and their corresponding outcomes.

RESULTS

A total of 3,823,490 and 1,875,705 patients were admitted to teaching and non-teaching hospitals during the study duration, respectively. The proportion of patients who underwent thrombectomy increased from 1.60 % to 7.02 % (p-value for trend p < 0.001) in teaching hospitals and from 0.32 % to 2.20 % (p-value trend p < 0.001) in non-teaching hospitals. The absolute increase in the number of acute ischemic stroke patients undergoing thrombectomy was highest in teaching hospitals particularly those with large bed size, an increase from 3635 patients in 2012 to 24,730 patients in 2020. Higher rates of intravenous thrombolysis and patient transfer prior to thrombectomy were seen in teaching hospitals compared with non-teaching hospitals.

CONCLUSIONS

The study highlights disparities between teaching and non-teaching hospitals, with teaching hospitals showing a disproportionately higher rate of thrombectomy adoption in acute ischemic stroke patients. Further studies are needed to understand the barriers to the adoption of thrombectomy in non-teaching hospitals.

System-level trends in ischemic stroke admissions after adding endovascular stroke capabilities in community hospitals

BACKGROUND

There is substantial interest in adding endovascular stroke therapy (EST) capabilities in community hospitals. Here, we assess the effect of transitioning to an EST-performing hospital (EPH) on acute ischemic stroke (AIS) admissions in a large hospital system including academic and community hospitals.

METHODS

From our prospectively collected multi-institutional registry, we collected data on AIS admissions at 10 hospitals in the greater Houston area from January 2014 to December 2022: one longstanding EPH (group A), three community hospitals that transitioned to EPHs in November 2017 (group B), and six community non-EPHs that remained non-EPH (group C). Primary outcomes were trends in total AIS admissions, large vessel occlusion (LVO) and non-LVO AIS, and tissue plasminogen activator (tPA) and EST use.

RESULTS

Among 20 317 AIS admissions, median age was 67 (IQR 57-77) years, 52.4% were male, and median National Institutes of Health Stroke Scale (NIHSS) was 4 (IQR 1-10). During the first 12 months after EPH transition, AIS admissions increased by 1.9% per month for group B, with non-LVO stroke increasing by 4.2% per month (P<0.001). A significant change occurred for group A at the transition point for all outcomes with decreasing rates in admissions for AIS, non-LVO AIS and LVO AIS, and decreasing rates of EST and tPA treatments (P<0.001).

CONCLUSION

Upgrading to EPH status was associated with a 2% per month increase in AIS admissions during the first year post-transition for the upgrading hospitals, but decreasing volumes and treatments at the established EPH. These findings quantify the impact on AIS admissions in hospital systems with increasing EST access in community hospitals.

Modeling optimal patient transport in a stroke network capable of remote telerobotic endovascular therapy

BACKGROUND

Telerobotic endovascular therapy (EVT) has the potential to decrease time to treatment and expand existing networks of care to more rural populations. It is currently unclear how its implementation would impact existing stroke networks.

METHODS

Conditional probability models were generated to predict the probability of excellent outcome for patients with suspected large vessel occlusion (LVO). A baseline stroke network was created for California using existing intravenous thrombolysis (IVT) centers and comprehensive stroke centers (CSCs) capable of IVT and EVT. Optimal transport decisions and catchment areas were generated for the baseline model and three hypothetical scenarios through conversion of IVT centers at various distances from a CSC into centers capable of telerobotic EVT [i.e., hospitals ≥15 and <50 miles from a CSC were converted (Scenario 1), ≥50 and <100 miles (Scenario 2), and ≥100 miles (Scenario 3)]. Procedural times and success rates were varied systematically.

RESULTS

Telerobotic EVT centers decreased median travel time for LVO patients in all three scenarios. The estimated number of robotically treated LVOs per year in Scenarios 1, 2, and 3 were 2,172, 740, and 212, respectively. Scenario 1 (15-50 miles) was the most sensitive to robotic time delay and success rate, but all three scenarios were more sensitive to decreases in procedural success rate compared to time delay.

CONCLUSIONS

Telerobotic EVT has the potential to improve care for stroke patients outside of major urban centers. Compared to procedural time delays in robotic EVT, a decrease in procedural success rate would not be well tolerated.

Mobile Stroke Units in Acute Ischemic Stroke: A Comprehensive Systematic Review and Meta-Analysis of 5 "T Letter" Domains

Intravenous thrombolysis (IVT) may be administered to stroke patients requiring immediate treatment more quickly than emergency medical services if certain conditions are met. These conditions include the presence of mobile stroke units (MSUs) with on-site treatment teams and a computed tomography scanner. We compared clinical outcomes of MSU conventional therapy by emergency medical services through a systematic review and meta-analysis. We searched key electronic databases from inception till September 2021. The primary outcomes were mortality at 7 and 90 days. The secondary outcomes included the modified Rankin Scale score at 90 days, alarm to IVT or intra-arterial recanalization, and time from symptom onset or last known well to thrombolysis. We included 19 controlled trials and cohort studies to conduct our final analysis. Our comparison revealed that 90-day mortality significantly decreased in the MSU group compared with the conventional care group [risk ratio = 0.82; 95% confidence interval (CI), 0.71-0.95], while there was no significant difference at 7 days (risk ratio = 0.89; 95% CI, 0.69-1.15). MSU achieved greater functional independence (modified Rankin Scale = 0-2) at 90 days (risk ratio = 1.08; 95% CI, 1.01-1.16). MSU was associated with shorter alarm to IVT or intra-arterial recanalization time (mean difference = -29.69; 95% CI, -34.46 to -24.92), treating patients in an earlier time window, as shown through symptom onset or last known well to thrombolysis (mean difference = -36.79; 95% CI, -47.48 to -26.10). MSU-treated patients had a lower rate of 90-day mortality and better 90-day functional outcomes by earlier initiation of IVT compared with conventional care.

Becoming a thrombectomy-capable stroke center: Clinical and medico-economical effectiveness at the hospital level

INTRODUCTION

Too few patients benefit from endovascular therapy (EVT) in large vessel occlusion acute stroke (LVOS), and various acute stroke care paradigms are currently investigated to reduce these inequalities in health access. We aimed to investigate whether newly set-up thrombectomy-capable stroke centers (TSC) offered a safe, effective and cost-effective procedure.

PATIENTS AND METHODS

This French retrospective study compared the outcomes of LVOS patients with an indication for EVT and treated at the Perpignan hospital before on-site thrombectomy was available (Primary stroke center), and after formation of local radiology team for neurointervention (TSC). Primary endpoints were 3-months functional outcomes, assessed by the modified Rankin scale. Various safety endpoints for ischemic and hemorragic procedural complications were assessed. We conducted a medico-economic analysis to estimate the cost-benefit of becoming a TSC for the hospital.

RESULTS

The differences between 422 patients in the PSC and 266 in the TSC were adjusted by the means of weighted logistic regression. Patients treated in the TSC had higher odds of excellent functional outcome (aOR 1.77 [1.16-2.72], p = 0.008), with no significant differences in the rates of procedural complications. The TSC setting shortened onset-to-reperfusion times by 144 min (95% CI [131-155]; p < 0.0001), and was cost-effective after 21 treated LVOS patients. On-site thrombectomy saves 10.825€ per patient for the hospital.

DISCUSSION

Our results demonstrate that the TSC setting improves functional outcomes and reduces intra-hospital costs in LVOS patients. TSCs could play a major public health role in acute stroke care and access to EVT.

Factors Associated With Premature Termination of Hyperacute Stroke Trials: A Review

BACKGROUND

We performed a review of acute stroke trials to determine features associated with premature termination of trial enrollment, defined by the authors as not meeting preplanned sample size.

METHODS AND RESULTS

MEDLINE was searched for randomized clinical stroke trials published in 9 major clinical journals between 2013 and 2022. We included randomized clinical trials that were phase 2 or 3 with a preplanned sample size ≥100 and a time-to-treatment within 24 hours of onset for transient ischemic attack, ischemic stroke, or intracerebral hemorrhage. Data were abstracted on trial features including trial design, inclusion criteria, imaging, location and number of sites, masking, treatment complexity, control group (standard therapy, placebo), industry involvement, and preplanned stopping rules (futility and efficacy). Least absolute shrinkage and selection operator regression was used to select the most important factors associated with premature termination; then, a multivariable logistic regression was fit including only the least absolute shrinkage and selection operator selected variables. Of 1475 studies assessed, 98 trials met eligibility criteria. Forty-five (46%) trials were prematurely terminated, of which 27% were stopped for benefit/efficacy, 20% for lack of money/slow enrollment, 18% for futility, 16% for newly available evidence, 17% for other reasons, and 4% due to harm. Complex trials (adjusted odds ratio [aOR], 2.76 [95% CI, 1.13-7.49]), presence of a futility rule (aOR, 4.43 [95% CI, 1.62-17.91]), and exclusion of prestroke dependency (none/slight disability only; aOR, 2.19 [95% CI, 0.84-6.72] versus dependency allowed) were identified as the strongest predictors.

CONCLUSIONS

Nearly half of acute stroke trials were terminated prematurely. Broadening inclusion criteria and simplifying trial design may decrease the likelihood of unplanned termination, whereas planned futility analyses may appropriately terminate trials early, saving money and resources.

Portable cerebral blood flow monitor to detect large vessel occlusion in patients with suspected stroke

BACKGROUND

Early detection of large vessel occlusion (LVO) facilitates triage to an appropriate stroke center to reduce treatment times and improve outcomes. Prehospital stroke scales are not sufficiently sensitive, so we investigated the ability of the portable Openwater optical blood flow monitor to detect LVO.

METHODS

Patients were prospectively enrolled at two comprehensive stroke centers during stroke alert evaluation within 24 hours of onset with National Institutes of Health Stroke Scale (NIHSS) score ≥2. A 70 s bedside optical blood flow scan generated cerebral blood flow waveforms based on relative changes in speckle contrast. Anterior circulation LVO was determined by CT angiography. A deep learning model trained on all patient data using fivefold cross-validation and learned discriminative representations from the raw speckle contrast waveform data. Receiver operating characteristic (ROC) analysis compared the Openwater diagnostic performance (ie, LVO detection) with prehospital stroke scales.

RESULTS

Among 135 patients, 52 (39%) had an anterior circulation LVO. The median NIHSS score was 8 (IQR 4-14). The Openwater instrument had 79% sensitivity and 84% specificity for the detection of LVO. The rapid arterial occlusion evaluation (RACE) scale had 60% sensitivity and 81% specificity and the Los Angeles motor scale (LAMS) had 50% sensitivity and 81% specificity. The binary Openwater classification (high-likelihood vs low-likelihood) had an area under the ROC (AUROC) of 0.82 (95% CI 0.75 to 0.88), which outperformed RACE (AUC 0.70; 95% CI 0.62 to 0.78; P=0.04) and LAMS (AUC 0.65; 95% CI 0.57 to 0.73; P=0.002).

CONCLUSIONS

The Openwater optical blood flow monitor outperformed prehospital stroke scales for the detection of LVO in patients undergoing acute stroke evaluation in the emergency department. These encouraging findings need to be validated in an independent test set and the prehospital environment.

Differences in outcome between left-sided and right-sided mechanical thrombectomy for acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Mechanical thrombectomy (MT) is a safe and effective treatment option for acute ischemic stroke due to large vessel occlusion. To investigate differences in outcomes between patients receiving left-sided and right-sided MT, we performed a systematic review and meta-analysis.

METHODS

A systematic literature review was performed using Embase, PubMed, Scopus, and Web of Science databases. Additional literature was searched for manually. Studies reporting safety and efficacy metrics for MT were included. Data regarding the modified Rankin scale (mRS), thrombolysis in cerebral infarction (TICI), symptomatic intracranial hemorrhage (sICH), and 90-day mortality were included. A random-effects model was used to calculate pooled odds ratios (ORs), mean differences (MDs), and 95% confidence intervals (CIs).

RESULTS

The literature search yielded 13 reports consisting of 19 studies ranging from 98 to 5590 patients. Patients presenting with left-sided stroke had a National Institutes of health stroke scale score 2.89 greater than patients presenting with right-sided stroke (MD = 2.89; 95% CI = 2.09-3.68; P-value < 0.001). There were no differences between left-sided and right-sided MT patients for mRS 0-2 (OR = 0.94; 95% CI = 0.85-1.04; P-value = 0.224), TICI 2b-3 (OR = 1.05; 95% CI = 0.88-1.25; P-value = 0.598), sICH (OR = 0.83; 95% CI = 0.61-1.14; P-value = 0.255), or 90-day mortality (OR = 1.06; 95% CI = 0.84-1.33; P-value = 0.610).

CONCLUSIONS

There does not appear to be a difference in outcomes for patients undergoing left-sided or right-sided thrombectomy.

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial

Importance

Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT).

Objective

To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes.

Design, Setting, and Participants

This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024.

Interventions

EVT vs MM.

Main Outcomes and Measures

Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication.

Results

A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80).

Conclusions and Relevance

Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Differential thrombectomy utilization across hospital classifications in the United States

OBJECTIVES

To determine hospital-level factors associated with thrombectomy uptake.

MATERIALS AND METHODS

The Nationwide Emergency Department Sample was retrospectively queried to determine the total number of thrombectomies performed based on different hospital characteristics. Joint point analysis was used to determine which years were associated with significant increases in the number of high-volume thrombectomy centers (ostensibly defined as >50 thrombectomies/year), thrombectomy-capable centers (>15 thrombectomies/year), and total number of thrombectomies performed. Multivariable logistic regression was used to determine hospital factors associated with having an increased odds of performing thrombectomies, and of being classified as a high-volume thrombectomy or a thrombectomy-capable center.

RESULTS

Between 2007-2020 there was a stepwise increase in the number of thrombectomy-capable and high-volume thrombectomy centers in the United States. In 2020, there were a total of 15,705 thrombectomies performed, with 89 high-volume thrombectomy centers, and 359 thrombectomy-capable centers. The number of thrombectomy-capable centers significantly increased after 2011. After 2013 and 2016 there was a significant change in the growth rate of high-volume thrombectomy centers. There was also a significant increase in the total number of thrombectomies performed after 2016. Hospital characteristics that were associated with an increased likelihood of being classified as thrombectomy-capable or high-volume included trauma level 1 and 2 hospitals.

CONCLUSIONS

Between 2007 and 2020, there was a marked growth in thrombectomy utilization for acute ischemic stroke. This growth outpaced new diagnoses of ischemic stroke, and was driven largely by certain hospital types, with the greatest rises following seminal publications of positive randomized thrombectomy trials.

Racial and ethnic disparities in the usage and outcomes of ischemic stroke treatment in the United States

OBJECTIVES

This study explores racial and ethnic differences in 1) receiving tissue plasminogen activator (tPA) and endovascular thrombectomy (EVT) as treatment for ischemic stroke and 2) outcomes and quality of care after use of tPA or EVT in the US.

MATERIALS AND METHODS

An observational analysis of 89,035 ischemic stroke patients from the 2019 National Inpatient Sample was conducted. We performed weighted logistic regressions between race and ethnicity and 1) tPA and EVT utilization and 2) in-hospital mortality. We also performed a weighted Poisson regression between race and ethnicity and length of stay (LOS) after tPA or EVT.

RESULTS

Non-Hispanic (NH) Black patients had significantly lower odds of receiving tPA (Adjusted odds ratio [AOR] = 0.85, 95 % Confidence Internal [C.I.]: 0.80-0.91) and EVT (AOR = 0.75, 95 % CI: 0.70-0.82) than NH White patients. Minority populations (including but not limited to NH Black, Hispanic, Pacific Islander, Native American, and Asian) had significantly longer hospital LOS after treatment with tPA or EVT. We did not find a significant difference between race/ethnicity and in-hospital mortality post-tPA or EVT.

CONCLUSIONS

While we failed to find a difference in in-hospital mortality, racial and ethnic disparities are still evident in the decreased usage of tPA and EVT and longer LOSs for racial and ethnic minority patients. This study calls for interventions to expand the utilization of tPA and EVT and advance quality of care post-tPA or EVT in order to improve stroke care for minority patients.

Geographical Requirements for the Applicability of the Results of the RACECAT Study to Other Stroke Networks

Background The RACECAT (Transfer to the Closest Local Stroke Center vs Direct Transfer to Endovascular Stroke Center of Acute Stroke Patients With Suspected Large Vessel Occlusion in the Catalan Territory) trial was the first randomized trial addressing the prehospital triage of acute stroke patients based on the distribution of thrombolysis centers and intervention centers in Catalonia, Spain. The study compared the drip-and-ship with the mothership paradigm in regions where a local thrombolysis center can be reached faster than the nearest intervention center (equipoise region). The present study aims to determine the population-based applicability of the results of the RACECAT study to 4 stroke networks with a different degree of clustering of the intervention centers (clustered, dispersed). Methods and Results Stroke networks were compared with regard to transport time saved for thrombolysis (under the drip-and-ship approach) and transport time saved for endovascular therapy (under the mothership approach). Population-based transport times were modeled with a local instance of an openrouteservice server using open data from OpenStreetMap.The fraction of the population in the equipoise region differed substantially between clustered networks (Catalonia, 63.4%; France North, 87.7%) and dispersed networks (Southwest Bavaria, 40.1%; Switzerland, 40.0%). Transport time savings for thrombolysis under the drip-and-ship approach were more marked in clustered networks (Catalonia, 29 minutes; France North, 27 minutes) than in dispersed networks (Southwest Bavaria and Switzerland, both 18 minutes). Conclusions Infrastructure differences between stroke networks may hamper the applicability of the results of the RACECAT study to other stroke networks with a different distribution of intervention centers. Stroke networks should assess the population densities and hospital type/distribution in the temporal domain before applying prehospital triage algorithms to their specific setting.

The clinical utility of dual-energy CT in post-thrombectomy care: Part 2, the predictive value of contrast density and volume for delayed hemorrhagic transformation

OBJECTIVES

Dual-energy CT allows differentiation between blood and iodinated contrast. This study aims to determine the predictive value of contrast density and volume on post-thrombectomy dual-energy CT for delayed hemorrhagic transformation and its impact on 90-day outcomes.

MATERIALS AND METHODS

A retrospective analysis was performed on patients who underwent thrombectomy for anterior circulation large-vessel occlusion at a comprehensive stroke center from 2018-2021. Per institutional protocol, all patients underwent dual-energy CT immediately post-thrombectomy and MRI or CT 24 hours afterward. The presence of hemorrhage and contrast staining was evaluated by dual-energy CT. Delayed hemorrhagic transformation was determined by 24-hour imaging and classified into petechial hemorrhage or parenchymal hematoma using ECASS III criteria. Univariable and multivariable analyses were performed to determine predictors and outcomes of delayed hemorrhagic transformation.

RESULTS

Of 97 patients with contrast staining and without hemorrhage on dual-energy CT, 30 and 18 patients developed delayed petechial hemorrhage and delayed parenchymal hematoma, respectively. On multivariable analysis, delayed petechial hemorrhage was predicted by anticoagulant use (OR,3.53;p=0.021;95%CI,1.19-10.48) and maximum contrast density (OR,1.21;p=0.004;95%CI,1.06-1.37;per 10 HU increase), while delayed parenchymal hematoma was predicted by contrast volume (OR,1.37;p=0.023;95%CI,1.04-1.82;per 10 mL increase) and low-density lipoprotein (OR,0.97;p=0.043;95%CI,0.94-1.00;per 1 mg/dL increase). After adjusting for potential confounders, delayed parenchymal hematoma was associated with worse functional outcomes (OR,0.07;p=0.013;95%CI,0.01-0.58) and mortality (OR,7.83;p=0.008;95%CI,1.66-37.07), while delayed petechial hemorrhage was associated with neither.

CONCLUSION

Contrast volume predicted delayed parenchymal hematoma, which was associated with worse functional outcomes and mortality. Contrast volume can serve as a useful predictor of delayed parenchymal hematoma following thrombectomy and may have implications for patient management.

The clinical utility of dual-energy CT in post-thrombectomy care: Part 1, predictors and outcomes of subarachnoid and intraparenchymal hemorrhage

OBJECTIVES

Dual-energy CT allows differentiation between blood and iodinated contrast. We aimed to determine predictors of subarachnoid and intraparenchymal hemorrhage on dual-energy CT performed immediately post-thrombectomy and the impact of these hemorrhages on 90-day outcomes.

MATERIALS AND METHODS

A retrospective analysis was performed on patients who underwent thrombectomy for anterior circulation large-vessel occlusion and subsequent dual-energy CT at a comprehensive stroke center from 2018-2021. The presence of contrast, subarachnoid hemorrhage, or intraparenchymal hemorrhage immediately post-thrombectomy was assessed by dual-energy CT. Univariable and multivariable analyses were performed to identify predictors of post-thrombectomy hemorrhages and 90-day outcomes. Patients with unknown 90-day mRS were excluded.

RESULTS

Of 196 patients, subarachnoid hemorrhage was seen in 17, and intraparenchymal hemorrhage in 23 on dual-energy CT performed immediately post-thrombectomy. On multivariable analysis, subarachnoid hemorrhage was predicted by stent retriever use in the M2 segment of MCA (OR,4.64;p=0.017;95%CI,1.49-14.35) and the number of thrombectomy passes (OR,1.79;p=0.019;95%CI,1.09-2.94;per an additional pass), while intraparenchymal hemorrhage was predicted by preprocedural non-contrast CT-based ASPECTS (OR,8.66;p=0.049;95%CI,0.92-81.55;per 1 score decrease) and preprocedural systolic blood pressure (OR,5.10;p=0.037;95%CI,1.04-24.93;per 10 mmHg increase). After adjusting for potential confounders, intraparenchymal hemorrhage was associated with worse functional outcomes (OR,0.25;p=0.021;95%CI,0.07-0.82) and mortality (OR,4.30;p=0.023,95%CI,1.20-15.36), while subarachnoid hemorrhage was associated with neither.

CONCLUSIONS

Intraparenchymal hemorrhage immediately post-thrombectomy was associated with worse functional outcomes and mortality and can be predicted by low ASPECTS and elevated preprocedural systolic blood pressure. Future studies focusing on management strategies for patients presenting with low ASPECTS or elevated blood pressure to prevent post-thrombectomy intraparenchymal hemorrhage are warranted.

Transradial balloon guide catheter placement for acute ischemic stroke thrombectomy: A systematic review and meta-analysis

BACKGROUND

Endovascular thrombectomy (EVT) is a treatment option for acute ischemic stroke due to large vessel occlusion. The use of a balloon-guided catheter (BGC) for EVT via transradial access (TRA) has emerged as a treatment approach, but its efficacy and safety compared to existing practices are uncertain.

METHODS

A systematic literature review was performed using Embase, PubMed, Scopus, Web of Science databases, and manual search. Studies reporting safety and efficacy metrics for TRA BGC EVT were included. Data regarding recanalization time, thrombolysis in cerebral infarction (TICI), modified Rankin scale (mRS), symptomatic intracranial hemorrhage (sICH), first pass effect (FPE), and additional complications was pooled using a random-effects model to calculate event rates and 95% confidence intervals (CI).

RESULTS

The search yielded five studies (n  =  117). The mean time from puncture to final recanalization was 34.5 (95% CI  =  30.5 to 39.14, I²  =  0%, P-value  =  0.37) min. Successful recanalization (TICI 2b-3) and complete recanalization (TICI 3) occurred in 96.6% (95% CI  =  91.24 to 98.71, I²  =  0%, P-value  =  0.99) and 55.2% (95% CI  =  42.14 to 67.54, I²  =  0%, P-value  =  0.39) of cases, respectively. FPE occurred in 67.5% (95% CI  =  51.73 to 80.10, I²  =  0%, P-value  =  0.56) of patients. mRS 0-2 was achieved in 41.2% (95% CI  =  27.34 to 56.65, I²  =  70%, P-value  =  0.07) of patients. sICH occurred in 5.0% (95% CI  =  1.25 to 17.91, I²  =  0%, P-value  =  1.00) of patients. Local complications of radial hematoma and radial vasospasm occurred in 5.0% (95% CI  =  0.49 to 12.36, I²  =  29%, P-value  =  0.24) and 2.1% (95% CI  =  1.25 to 17.91, I²  =  71%, P-value  =  0.03) of cases, respectively. Switch to femoral access was necessary in 3.7% (95% CI  =  0.00 to 14.07, I²  =  68%, P-value  =  0.02) of procedures. The average number of passes per procedure was 1.6 (95% CI  =  1.15 to 2.11, I²  =  88%, P-value < 0.001).

CONCLUSION

TRA BGC EVT has potential as a safe and efficacious treatment option compared to existing methods. However, additional, prospective studies are necessary to inform clinical decision making.

Robotically-assisted neuro-endovascular procedures: Single-Center Experience and a Review of the Literature

INTRODUCTION

Robotics could expand treatment of rapidly progressive pathologies such as acute ischemic stroke, with the potential to provide populations in need prompt access to neuro-endovascular procedures.

METHODS

Robotically-assisted (RA) neuro-endovascular procedures (RANPs) performed at our institution were retrospectively examined (RA-group, RG). A control group of manual neuro-endovascular procedures was selected (manual group, MG). Total operating room (OR) time, procedural time, contrast media use, fluoroscopy time, conversion from RA to manual control, procedural success, and complication rates were compared. A learning curve was identified.

RESULTS

Forty-one (41) RANPs were analyzed. Ages ranged from 20-82 y.o. Indications included diagnostic cerebral angiography (37), extracranial carotid artery stenting (3), and transverse sinus stent (1). Total OR time was longer in RG (median 86 vs. 71 min, p < 0.01). Procedural time (median 56 vs. 45 min, p = 0.12), fluoroscopy time (median 12 vs. 12 min, p = 0.69) and contrast media usage (82 vs. 92 ml, p = 0.54) were not significantly different. Patient radiation exposure was similar, considering similar fluoroscopy times. Radiation exposure and lead apron use were virtually absent for the main surgeon in RG. Procedural success was 83% and conversion from RA to manual control was 17% in RG. No treatment-related complications occurred. A learning curve showed that, after the fifth procedure, procedural times reduced and stabilized.

CONCLUSIONS

This series may contribute to further demonstrating the safety and feasibility of RANPs. RANPs can potentially reduce radiation exposure and physical burden for health personnel, expand acute cerebrovascular treatment to underserved areas, and enhance telementoring. Prospective studies are necessary for results to be generalized.

Patterns of Care in Patients with Basilar Artery Occlusion (BAO): A Population-Based Study

Basilar artery occlusion (BAO) is associated with high morbidity and mortality. Endovascular therapy (EVT) has been shown to be beneficial in acute BAO patients. This retrospective observational study used the National Inpatient Sample (NIS) database to identify BAO patients using the International Classification of Diseases (ICD). Multivariable models were used to evaluate the association of risk factors, comorbidities, length of stay (LOS) in hospital, total cost, disposition, and transfer status. A total of 1120 (447 females, 39.95%) patients were identified, with a higher proportion of White individuals (66.8% vs. 57.6%), atrial fibrillation (31.5% vs. 17.2%; p < 0.0001), and peripheral vascular disease (21.2% vs. 13.7%; p = 0.009). A lower proportion of individuals with diabetes mellitus (32.1% vs. 39.5%; p = 0.05) was found in the EVT group. Majority of the patients (924/1120, 82.5%) were treated at the urban teaching facility, which also performed most of the EVT procedures (164, 89.13%), followed by non-academic urban (166, 14.8%) and rural (30, 2.7%) hospitals. Most patients (19/30, 63%) admitted to rural hospitals were transferred to other facilities. Urban academic hospitals also had the highest median LOS (8.9 days), cost of hospitalization (USD 117,261), and disposition to home (32.6%). This study observed distinct patterns and geographical disparities in the acute treatment of BAO patients. There is a need for national- and state-level strategies to improve access to stroke care.

Thrombectomy-Capable Stroke Centre-A Key to Acute Stroke Care System Improvement? Retrospective Analysis of Safety and Efficacy of Endovascular Treatment in Cardiac Cathlab

The optimal structure of the acute ischaemic stroke treatment network is unknown and eagerly sought. To make it most effective, different treatment and transportation strategies have been developed and investigated worldwide. Since only a fraction of acute stroke patients with large vessel occlusion are treated, a new entity-thrombectomy-capable stroke centre (TCSC)-was introduced to respond to the growing demand for timely endovascular treatment. The purpose of this study was to present the early experience of the first 70 patients treated by mechanical means in a newly developed cardiac Cathlab-based TCSC. The essential safety and efficacy measures were recorded and compared with those reported in the invasive arm of the HERMES meta-analysis-the largest published dataset on the subject. We found no significant differences in terms of clinical and safety outcomes, such as early neurological recovery, level of functional independence at 90 days, symptomatic intracranial haemorrhage, parenchymal haematoma type 2, and mortality. These encouraging results obtained in the small endovascular centre may be an argument for the introduction of the TCSC into operating stroke networks to increase patient access to timely treatment and to improve clinical outcomes.

Ultra-Long Transfers for Endovascular Thrombectomy-Mission Impossible?: The Australia-New Zealand Experience

BACKGROUND

Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial; however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred >300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0-2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS.

METHODS

This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021).

RESULTS

There were 131 patients; the median age was 64 [53-74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12-22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1-3] versus 3 [1-6] in the patients selected with noncontrast CT+CT angiography, P=0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01-0.19]; P<0.01).

CONCLUSIONS

In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.

Access to Mechanical Thrombectomy for Stroke: Center Qualifications, Prehospital Management, and Geographic Disparities

Mechanical thrombectomy (MT) became the "gold-standard" treatment for most patients with acute ischemic stroke due to anterior circulation large vessel occlusion. With such a remarkable paradigm shift, it is important that this modality of treatment becomes widely and homogeneously available throughout the United States and other countries. Although the time window for MT is large (24 hours in selected patients), time is still a major determinant of outcome. Several variables are involved in achieving timely access of MT for the majority of the population: prehospital management systems, transportation models, in-hospital workflow organization, accreditation and infrastructure of centers, training of neurointervention professionals, and geographic distribution of centers. The current situation in the United States regarding MT access is marked by geographic and socioeconomic disparities. We provide an overview of current challenges and solutions in achieving more universal access to MT for the population.

Mechanical Thrombectomy in the Late Presentation of Anterior Circulation Large Vessel Occlusion Stroke: A Guideline From the Society of Vascular and Interventional Neurology Guidelines and Practice Standards Committee

Background and Purpose

Recent clinical trials investigating endovascular therapy (EVT) in the extended time window have opened new treatment paradigms for late-presenting patients with large vessel occlusion (LVO) stroke. The aim of this guideline is to provide up to date recommendations for the diagnosis, selection, and medical or endovascular treatment of patients with LVO presenting in the extended time window.

Methods

The Society of Vascular & Interventional Neurology (SVIN) Guidelines and Practice Clinical Standards (GAPS) committee assembled a writing group and recruited interdisciplinary experts to review and evaluate the current literature. Recommendations were assigned by the writing group using the SVIN-GAPS Class of Recommendation/Level of Evidence algorithm and SVIN GAPS guideline format. The final guideline was approved by all members of the writing group, the GAPS committee, and the SVIN board of directors.

Results

Literature review yielded three high quality randomized trials and several observational studies that have been extracted to derive the enclosed summary recommendations. In patients with LVO presenting in the 6-to-24-hour window, and with clinical imaging mismatch as defined by the DAWN and DEFUSE 3 studies, EVT is recommended. Non contrast CT can be used to evaluate infarct size as sole imaging modality for patient selection, particularly when access to CT perfusion or MRI is limited, or if their performance would incur substantial delay to treatment. In addition, several clinical questions were reviewed based on the available evidence and consensus grading.

Conclusion

These guidelines provide practical recommendations based on recent evidence on the diagnosis, selection, and treatment of patients with LVO stroke presenting in the extended time window.

Reduction in Door-to-Groin Puncture Time for Endovascular Treatment in Acute Ischemic Stroke Patients With Large Vessel Occlusion

Background The outcome of mechanical thrombectomy for large vessel occlusion (LVO) in patients with acute ischemic stroke (AIS) is time-dependent. In the current stroke workflow, the pre-hospital delay is one of the most common reasons for an increase in door-to-groin puncture time (DGPT). In the present study, we sought to compare the difference in (DGPT) before and after the implementation of the Ventura Emergent Large Vessel Occlusion Score (VES) protocol for LVO. Methods VES was implemented in the Ventura County of California by Emergency Medical Services (EMS). We performed a retrospective analysis to compare DGPT of patients undergoing endovascular treatment (EVT) pre- and post-VES implementation. Mean and standard deviation was reported for the continuous variable 'time for intra-arterial (IA) treatment' in minutes. The Mann-Whitney test was used for the comparison of the variable between the two groups. analyses were performed using SAS v9.4 (SAS Institute Inc., Cary, NC) with a significant p-value of ≤0.05. Results A total of 304 (males: 142 and females: 162) patients were alerted of the stroke code by the EMS. VES was positive in 139 patients. Of these, 64 (46%) were males and 75 (54%) were females. VES score of 1, 2, 3, and 4 were recorded in 57 (41%), 44 (31.6%), 31 (22.3%), and 7 (5%) patients, respectively. A total of 48 VES-positive patients underwent EVT. There were 62 patients who underwent EVT before the implementation of the VES protocol. The mean DGPT for the EVT among post-VES patients was 65 minutes, which was significantly (p=0.0009) shorter than the mean DGPT of 109 minutes among pre-VES patients. Conclusion VES is a simplified and effective tool for identifying LVO in the field. Implementation of VES showed significantly reduced DGPT in LVO patients.

Prediction modelling the impact of onset to treatment time on the modified Rankin Scale score at 90 days for patients with acute ischaemic stroke

Introduction

Shortening the time from stroke onset to treatment increases the effectiveness of endovascular stroke therapies.

Aim

This study aimed to predict the modified Rankin Scale score at 90 days post-stroke (mRS-90d score) in patients with acute ischaemic stroke (AIS) with respect to four types of treatment: conservative therapy (CVT), intravenous thrombolysis only (IVT), mechanical thrombectomy only (MT) and pretreatment with IVT before MT (IVT+MT).

Patients and methods

This nationwide observational study included 124 484 confirmed cases of acute stroke in Sweden over 6 years (2012–2017). The associations between onset-to-treatment time (OTT), patient age and hospital admission National Institutes of Health Stroke Scale (NIHSS) score with the five-levelled mRS-90d score were retrospectively studied. A generalised linear model (GLM) was fitted to predict the mRS-90d scores for each patient group.

Results

The fitted GLM for CVT patients is a function of age and NIHSS score. For IVT, MT and IVT+MT patients, GLMs additionally employed OTT variables. By reducing the mean OTTs by 15 min, the number needed-to-treat (NNT) for one patient to make a favourable one-step shift in the mRS was 30 for IVT, 48 for MT and 21 for IVT+MT.

Discussion and conclusion

This study demonstrates linear associations of mRS-90d score with OTT for IVT, MT and IVT+MT, and shows in absolute effects measures that OTT reductions for IVT and/or MT produces substantial health gains for patients with AIS. Even moderate OTT reductions led to sharp drops in the NNT.

Travel time and distance for bypass and non-bypass routing of stroke patients in the USA

BACKGROUND

Endovascular thrombectomy is not available at all hospitals that offer intravenous thrombolysis, prompting debate regarding the preferred transport destination for acute ischemic stroke. This study aimed to quantify real-world travel time and distance of bypass and non-bypass transport models for large-vessel occlusion (LVO) and non-LVO stroke.

METHODS

This cross-sectional study included population data of census tracts in the contiguous USA from the 2014-2018 United States Census Bureau's American Community Survey, stroke (thrombolysis-capable) and thrombectomy-capable centers certified by a state or national body, and road network data from a mapping service. Census tracts were categorized by urbanization level. Data were retrieved from March to November 2020. Travel times and distances were calculated for each census tract to each of the following: nearest stroke center (nearest), nearest thrombectomy-capable center (bypass), and nearest stroke center then to the nearest thrombectomy-capable center (transfer). Population-weighted median and IQR were calculated nationally and by urbanization.

RESULTS

72 538 census tracts, 2388 stroke hospitals, and 371 thrombectomy-capable centers were included. Nationally, population-weighted median travel time for nearest and bypass routing was 11.7 min (IQR 7.7-19.3) and 26.4 min (14.8-55.1), respectively. For transfer routing, the population-weighted median travel times with 60 min, 90 min, and 120 min door-in-door-out times were 94.1 min (78.5-127.7), 124.1 min (108.5-157.7), and 154.1 min (138.4-187.6), respectively.

CONCLUSIONS

Bypass routing offers modest travel time benefits for LVO patients and incurs modest penalties for non-LVO patients. Differences are greatest in rural areas. A majority of Americans live in areas for which current guidelines recommend bypass.

European Stroke Organisation - European Society for Minimally Invasive Neurological Therapy expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischaemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischaemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach. For stroke patients with anterior circulation LVO directly admitted to a MT-capable centre ('mothership') within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a centre without MT facilities and eligible for IVT ≤4.5 hrs and MT, we recommend IVT followed by rapid transfer to a MT capable-centre ('drip-and-ship') in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischaemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

European Stroke Organisation (ESO)-European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach.For stroke patients with anterior circulation LVO directly admitted to a MT-capable center ('mothership') within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a center without MT facilities and eligible for IVT ≤4.5 hours and MT, we recommend IVT followed by rapid transfer to a MT capable-center ('drip-and-ship') in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

Mechanical Thrombectomy Access for All? Challenges in Increasing Endovascular Treatment for Acute Ischemic Stroke in the United States

Mechanical thrombectomy (MT) is the most effective treatment for selected patients with an acute ischemic stroke due to emergent large vessel occlusions (LVOs). There is an urgent need to identify and address challenges in access to MT to maximize the numbers of patients who can benefit from this treatment. Barriers in access to MT include delays in evaluation and accurate diagnosis of LVO leading to inappropriate triage, logistical delays related to availability of facilities and trained interventionalists, and financial hurdles that affect treatment reimbursement. Collection of regional data related to these barriers is critical to better understand current access gaps and a measurable access score to thrombectomy could be useful to plan local public health intervention.

National implementation of reperfusion for acute ischaemic stroke in England: How should services be configured? A modelling study

Objectives

To guide policy when planning thrombolysis (IVT) and thrombectomy (MT) services for acute stroke in England, focussing on the choice between ‘mothership’ (direct conveyance to an MT centre) and ‘drip-and-ship’ (secondary transfer) provision and the impact of bypassing local acute stroke centres.

Design

Outcome-based modelling study.

Setting

107 acute stroke centres in England, 24 of which provide IVT and MT (IVT/MT centres) and 83 provide only IVT (IVT-only units).

Participants

242,874 emergency admissions with acute stroke over 3 years (2015–2017).

Intervention

Reperfusion delivered by drip-and-ship, mothership or ‘hybrid’ models; impact of additional travel time to directly access an IVT/MT centre by bypassing a more local IVT-only unit; effect of pre-hospital selection for large artery occlusion (LAO).

Main outcome measures

Population benefit from reperfusion, time to IVT and MT, admission numbers to IVT-only units and IVT/MT centres.

Results

Without pre-hospital selection for LAO, 94% of the population of England live in areas where the greatest clinical benefit, assuming unknown patient status, accrues from direct conveyance to an IVT/MT centre. However, this policy produces unsustainable admission numbers at these centres, with 78 out of 83 IVT-only units receiving fewer than 300 admissions per year (compared to 3 with drip-and-ship). Implementing a maximum permitted additional travel time to bypass an IVT-only unit, using a pre-hospital test for LAO, and selecting patients based on stroke onset time, all help to mitigate the destabilising effect but there is still some significant disruption to admission numbers, and improved selection of patients suitable for MT selectively reduces the number of patients who would receive IVT at IVT-only centres, challenging the sustainability of IVT expertise in IVT-only centres.

Conclusions

Implementation of reperfusion for acute stroke based solely on achieving the maximum population benefit potentially leads to destabilisation of the emergency stroke care system. Careful planning is required to create a sustainable system, and modelling may be used to help planners maximise benefit from reperfusion while creating a sustainable emergency stroke care system.

Reperfusion Therapies for Children With Arterial Ischemic Stroke

ABSTRACT

Modern hyperacute reperfusion therapies including intravenous thrombolysis and mechanical thrombectomy have transformed the management of arterial ischemic stroke (AIS) in adults. Multiple randomized clinical trials have demonstrated that these therapies enable remarkable improvements in clinical outcome for properly selected patients with AIS. Because pediatric patients were excluded from predicate clinical trials, there is a conspicuous lack of data to guide selection of therapies and inform age-adjusted and pathology-oriented treatment modifications for children. Specifically, technical guidance concerning treatment eligibility, drug dosing, and device implementation is lacking. This review aims to outline important features that differentiate pediatric AIS from adult AIS and provide practical strategies that will assist the stroke specialist with therapeutic decision making.

Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

BACKGROUND

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

METHODS

In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.

RESULTS

We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.

CONCLUSIONS

In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

Investigating the "Weekend Effect" on Outcomes of Patients Undergoing Endovascular Mechanical Thrombectomy for Ischemic Stroke

OBJECTIVES

With growing evidence of its efficacy for patients with large-vessel occlusion (LVO) ischemic stroke, the use of endovascular thrombectomy (EVT) has increased. The "weekend effect," whereby patients presenting during weekends/off hours have worse clinical outcomes than those presenting during normal working hours, is a critical area of study in acute ischemic stroke (AIS). Our objective was to evaluate whether a "weekend effect" exists in patients undergoing EVT.

METHODS

This retrospective, cross-sectional analysis of the 2016-2018 Nationwide Inpatient Sample data included patients ≥18 years with documented diagnosis of ischemic stroke (ICD-10 codes I63, I64, and H34.1), procedural code for EVT, and National Institutes of Health Stroke Scale (NIHSS) score; the exposure variable was weekend vs. weekday treatment. The primary outcome was in-hospital death; secondary outcomes were favorable discharge, extended hospital stay (LOS), and cost. Logistic regression models were constructed to determine predictors for outcomes.

RESULTS

We identified 6052 AIS patients who received EVT (mean age 68.7±14.8 years; 50.8% female; 70.8% White; median (IQR) admission NIHSS 16 (10-21). The primary outcome of in-hospital death occurred in 560 (11.1%); the secondary outcome of favorable discharge occurred in 1039 (20.6%). The mean LOS was 7.8±8.6 days. There were no significant differences in the outcomes or cost based on admission timing. In the mixed-effects models, we found no effect of weekend vs. weekday admission on in-hospital death, favorable discharge, or extended LOS.

CONCLUSION

These results demonstrate that the "weekend effect" does not impact outcomes or cost for patients who undergo EVT for LVO.

Direct to Angiography vs Repeated Imaging Approaches in Transferred Patients Undergoing Endovascular Thrombectomy

Importance

A direct to angiography (DTA) treatment paradigm without repeated imaging for transferred patients with large vessel occlusion (LVO) may reduce time to endovascular thrombectomy (EVT). Whether DTA is safe and associated with better outcomes in the late (>6 hours) window is unknown. Also, DTA feasibility and effectiveness in reducing time to EVT during on-call vs regular-work hours and the association of interfacility transfer times with DTA outcomes have not been established.

Objective

To evaluate the functional and safety outcomes of DTA vs repeated imaging in the different treatment windows and on-call hours vs regular hours.

Design, Setting, and Participants

This pooled retrospective cohort study at 6 US and European comprehensive stroke centers enrolled adults (aged ≥18 years) with anterior circulation LVO (internal cerebral artery or middle cerebral artery subdivisions M1/M2) and transferred for EVT within 24 hours of the last-known-well time from January 1, 2014, to February 29, 2020.

Exposures

Repeated imaging (computed tomography with or without computed tomographic angiography or computed tomography perfusion) before EVT vs DTA.

Main Outcomes and Measures

Functional independence (90-day modified Rankin Scale score, 0-2) was the primary outcome. Symptomatic intracerebral hemorrhage, mortality, and time metrics were also compared between the DTA and repeated imaging groups.

Results

A total of 1140 patients with LVO received EVT after transfer, including 327 (28.7%) in the DTA group and 813 (71.3%) in the repeated imaging group. The median age was 69 (interquartile range [IQR], 59-78) years; 529 were female (46.4%) and 609 (53.4%) were male. Patients undergoing DTA had greater use of intravenous alteplase (200 of 327 [61.2%] vs 412 of 808 [51.0%]; P = .002), but otherwise groups were similar. Median time from EVT center arrival to groin puncture was faster with DTA (34 [IQR, 20-62] vs 60 [IQR, 37-95] minutes; P < .001), overall and in both regular and on-call hours. Three-month functional independence was higher with DTA overall (164 of 312 [52.6%] vs 282 of 763 [37.0%]; adjusted odds ratio [aOR], 1.85 [95% CI, 1.33-2.57]; P < .001) and during regular (77 of 143 [53.8%] vs 118 of 292 [40.4%]; P = .008) and on-call (87 of 169 [51.5%] vs 164 of 471 [34.8%]; P < .001) hours. The results did not vary by time window (0-6 vs >6 to 24 hours; P = .88 for interaction). Three-month mortality was lower with DTA (53 of 312 [17.0%] vs 186 of 763 [24.4%]; P = .008). A 10-minute increase in EVT-center arrival to groin puncture in the repeated imaging group correlated with 5% reduction in the functional independence odds (aOR, 0.95 [95% CI, 0.91-0.99]; P = .01). The rates of modified Rankin Scale score of 0 to 2 decreased with interfacility transfer times of greater than 3 hours in the DTA group (96 of 161 [59.6%] vs 15 of 42 [35.7%]; P = .006), but not in the repeated imaging group (75 of 208 [36.1%] vs 71 of 192 [37.0%]; P = .85).

Conclusions and Relevance

The DTA approach may be associated with faster treatment and better functional outcomes during all hours and treatment windows, and repeated imaging may be reasonable with prolonged transfer times. Optimal EVT workflow in transfers may be associated with faster, safe reperfusion with improved outcomes.

Clinical and Neuroimaging Outcomes of Direct Thrombectomy vs Bridging Therapy in Large Vessel Occlusion: Analysis of the SELECT Cohort Study

OBJECTIVE

To evaluate the comparative safety and efficacy of direct endovascular thrombectomy (dEVT) compared to bridging therapy (BT; IV tissue plasminogen activator + EVT) and to assess whether BT potential benefit relates to stroke severity, size, and initial presentation to EVT vs non-EVT center.

METHODS

In a prospective multicenter cohort study of imaging selection for endovascular thrombectomy (Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke [SELECT]), patients with anterior circulation large vessel occlusion (LVO) presenting to EVT-capable centers within 4.5 hours from last known well were stratified into BT vs dEVT. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] score 0-2). Secondary outcomes included a shift across 90-day mRS grades, mortality, and symptomatic intracranial hemorrhage. We also performed subgroup analyses according to initial presentation to EVT-capable center (direct vs transfer), stroke severity, and baseline infarct core volume.

RESULTS

We identified 226 LVOs (54% men, mean age 65.6 ± 14.6 years, median NIH Stroke Scale [NIHSS] score 17, 28% received dEVT). Median time from arrival to groin puncture did not differ in patients with BT when presenting directly (dEVT 1.43 [interquartile range (IQR) 1.13-1.90] hours vs BT 1.58 [IQR 1.27-2.02] hours, p = 0.40) or transferred to EVT-capable centers (dEVT 1.17 [IQR 0.90-1.48] hours vs BT 1.27 [IQR 0.97-1.87] hours, p = 0.24). BT was associated with higher odds of 90-day functional independence (57% vs 44%, adjusted odds ratio [aOR] 2.02, 95% confidence interval [CI] 1.01-4.03, p = 0.046) and functional improvement (adjusted common OR 2.06, 95% CI 1.18-3.60, p = 0.011) and lower likelihood of 90-day mortality (11% vs 23%, aOR 0.20, 95% CI 0.07-0.58, p = 0.003). No differences in any other outcomes were detected. In subgroup analyses, patients with BT with baseline NIHSS scores <15 had higher functional independence likelihood compared to those with dEVT (aOR 4.87, 95% CI 1.56-15.18, p = 0.006); this association was not evident for patients with NIHSS scores ≥15 (aOR 1.05, 95% CI 0.40-2.74, p = 0.92). Similarly, functional outcomes improvements with BT were detected in patients with core volume strata (ischemic core <50 cm3: aOR 2.10, 95% CI 1.02-4.33, p = 0.044 vs ischemic core ≥50 cm3: aOR 0.41, 95% CI 0.01-16.02, p = 0.64) and transfer status (transferred: aOR 2.21, 95% CI 0.93-9.65, p = 0.29 vs direct to EVT center: aOR 1.84, 95% CI 0.80-4.23, p = 0.15).

CONCLUSIONS

BT appears to be associated with better clinical outcomes, especially with milder NIHSS scores, smaller presentation core volumes, and those who were "dripped and shipped." We did not observe any potential benefit of BT in patients with more severe strokes.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02446587.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with ischemic stroke from anterior circulation LVO within 4.5 hours from last known well, BT compared to dEVT leads to better 90-day functional outcomes.

Reliability of Field Assessment Stroke Triage for Emergency Destination Scale Use by Paramedics: Mobile Stroke Unit First-Year Experience

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Access to Mechanical Thrombectomy for Ischemic Stroke in the United States

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Dose Escalation and Safety of Capsaicin for Cerebral Perfusion Augmentation: A Pilot Study

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Long-Term Administration of Triterpenoids From Ganoderma lucidum Mitigates Age-Associated Brain Physiological Decline via Regulating Sphingolipid Metabolism and Enhancing Autophagy in Mice

With the advent of the aging society, how to grow old healthily has become an important issue for the whole of society. Effective intervention strategies for healthy aging are most desired, due to the complexity and diversity of genetic information, it is a pressing concern to find a single drug or treatment to improve longevity. In this study, long-term administration of triterpenoids of Ganoderma lucidum (TGL) can mitigate brain physiological decline in normal aging mice. In addition, the age-associated pathological features, including cataract formation, hair loss, and skin relaxation, brown adipose tissue accumulation, the β-galactosidase staining degree of kidney, the iron death of spleen, and liver functions exhibit improvement. We used the APP/PS1 mice and 3 × Tg-AD mice model of Alzheimer's Disease (AD) to further verify the improvement of brain function by TGL and found that Ganoderic acid A might be the effective constituent of TGL for anti-aging of the brain in the 3 × Tg-AD mice. A potential mechanism of action may involve the regulation of sphingolipid metabolism, prolonging of telomere length, and enhance autophagy, which allows for the removal of pathological metabolites.

A Review of Robotic Interventional Neuroradiology

Robotic interventional neuroradiology is an emerging field with the potential to enhance patient safety, reduce occupational hazards, and expand systems of care. Endovascular robots allow the operator to precisely control guidewires and catheters from a lead-shielded cockpit located several feet (or potentially hundreds of miles) from the patient. This has opened up the possibility of expanding telestroke networks to patients without access to life-saving procedures such as stroke thrombectomy and cerebral aneurysm occlusion by highly-experienced physicians. The prototype machines, first developed in the early 2000s, have evolved into machines capable of a broad range of techniques, while incorporating newly automated maneuvers and safety algorithms. In recent years, preliminary clinical research has been published demonstrating the safety and feasibility of the technology in cerebral angiography and intracranial intervention. The next step is to conduct larger, multisite, prospective studies to assess generalizability and, ultimately, improve patient outcomes in neurovascular disease.

Effect of off-hour versus work-hour thrombolysis for acute ischemic stroke on emergency department patients' outcome: a retrospective study

OBJECTIVE

Early management of patients with acute ischemic stroke is crucial regardless of the time of presentation. The aim of the study was to evaluate the effect of off-hours management of patients with ischemic stroke that underwent thrombolytic therapy in the emergency department.

METHODS

This is a single-center retrospective study included ischemic stroke patients who received thrombolysis in the emergency department from January 2009 to April 2017. Patients who presented between 08:00 and 17:00 Monday to Friday were in the 'work-hour group (group 1)' versus others who were considered 'off-hours (group 2)'. Primary endpoint was 3-month mortality. Secondary endpoints included the National Institutes of Health Stroke Scale and dramatic recovery rate at 24 h, intracranial hemorrhage, systemic hemorrhage and modified Rankin Scale at the 3 months. Symptom-to-needle time, door-to-computed tomography time, and door-to-needle time were also compared between groups.

RESULTS

A total of 399 ischemic stroke patients were included in the analysis, 137 (34%) during work-hours and 262 (66%) during off-hours. The mortality rate was not different at 3 months between groups: 24 (17.5%) in the work-hours group versus 38 (14.5%) in the off-hours group [odds ratio 1.25; 95% confidence interval (CI), 0. 72-2.19]. There were no differences between groups on secondary endpoints. The mean time of symptom-to-needle was significantly higher during off-hours (mean difference: 18.4 min; 95% CI, 7.81-29.0).

CONCLUSIONS

In this study, there were no significant differences in mortality and functional outcomes at 3 months between patients who underwent off-hour or work-hour thrombolysis in the emergency department.

Mapping access to endovascular stroke care in the USA and implications for transport models

BACKGROUND

The purpose of this cross-sectional study was to determine the percentage of the US population with 60 min ground or air access to accredited or state-designated endovascular-capable stroke centers (ECCs) and non-endovascular capable stroke centers (NECCs) and the percentage of NECCs with an ECC within a 30 min drive.

METHODS

Stroke centers were identified and classified broadly as ECCs or NECCs. Geographic mapping of stroke centers was performed. The population was divided into census blocks, and their centroids were calculated. Fastest air and ground travel times from centroid to nearest ECC and NECC were estimated.

RESULTS

Overall, 49.6% of US residents had 60 min ground access to ECCs. Approximately 37.7% (113 million) lack 60 min ground or air access to ECCs. Approximately 84.4% have 60 min access to NECCs. Ground-only access was available to 77.9%. Approximately 738 NECCs (45.4%) had an ECC within a 30 min drive.

CONCLUSION

Nearly one-third of the US population lacks 60 min access to endovascular stroke care, but this is highly variable. Transport models and planning of additional centers should be tailored to each state depending on location and proximity of existing facilities.

Hydroxyethylstarch revisited for acute brain injury treatment

Infusion of the colloid hydroxyethylstarch has been used for volume substitution to maintain hemodynamics and microcirculation after e.g., severe blood loss. In the last decade it was revealed that hydroxyethylstarch can aggravate acute kidney injury, especially in septic patients. Because of the serious risk for critically ill patients, the administration of hydroxyethylstarch was restricted for clinical use. Animal studies and recently published in vitro experiments showed that hydroxyethylstarch might exert protective effects on the blood-brain barrier. Since the prevention of blood-brain barrier disruption was shown to go along with the reduction of brain damage after several kinds of insults, we revisit the topic hydroxyethylstarch and discuss a possible niche for the application of hydroxyethylstarch in acute brain injury treatment.

Utility of Severity-Based Prehospital Triage for Endovascular Thrombectomy: ACT-FAST Validation Study

BACKGROUND AND PURPOSE

Severity-based assessment tools may assist in prehospital triage of patients to comprehensive stroke centers (CSCs) for endovascular thrombectomy (EVT), but criticisms regarding diagnostic inaccuracy have not been adequately addressed. This study aimed to quantify the benefits and disadvantages of severity-based triage in a large real-world paramedic validation of the Ambulance Clinical Triage for Acute Stroke Treatment (ACT-FAST) algorithm.

METHODS

Ambulance Victoria paramedics assessed the prehospital ACT-FAST algorithm in patients with suspected stroke from November 2017 to July 2019 following an 8-minute training video. All patients were transported to the nearest stroke center as per current guidelines. ACT-FAST diagnostic accuracy was compared with hospital imaging for the presence of large vessel occlusion (LVO) and need for CSC-level care (LVO, intracranial hemorrhage, and tumor). Patient-level time saving to EVT was modeled using a validated Google Maps algorithm. Disadvantages of CSC bypass examined potential thrombolysis delays in non-LVO infarcts, proportion of patients with false-negative EVT, and CSC overburdening.

RESULTS

Of 517 prehospital assessments, 168/517 (32.5%) were ACT-FAST positive and 132/517 (25.5%) had LVO. ACT-FAST sensitivity and specificity for LVO was 75.8% and 81.8%, respectively. Positive predictive value was 58.8% for LVO and 80.0% when intracranial hemorrhage and tumor (CSC-level care) were included. Within the metropolitan region, 29/55 (52.7%) of ACT-FAST-positive patients requiring EVT underwent a secondary interhospital transfer. Prehospital bypass with avoidance of secondary transfers was modeled to save 52 minutes (95% CI, 40.0-61.5) to EVT commencement. ACT-FAST was false-positive in 8 patients receiving thrombolysis (8.1% of 99 non-LVO infarcts) and false-negative in 4 patients with EVT requiring secondary transfer (5.4% of 74 EVT cases). CSC bypass was estimated to over-triage 1.1 patients-per-CSC-per-week in our region.

CONCLUSIONS

The overall benefits of an ACT-FAST algorithm bypass strategy in expediting EVT and avoiding secondary transfers are estimated to substantially outweigh the disadvantages of potentially delayed thrombolysis and over-triage, with only a small proportion of EVT patients missed.