Thrombectomy Centre Research Articles

Thrombectomy for Stroke With Large Infarct on Noncontrast CT

Recent large infarct thrombectomy trials used heterogeneous imaging modalities and time windows for patient selection. Noncontrast computed tomographic (CT) scan is the most common stroke imaging approach. It remains uncertain whether thrombectomy is effective for patients with large infarcts identified using noncontrast CT alone within 24 hours of stroke onset. To evaluate the effect of thrombectomy in patients with a large infarct on a noncontrast CT scan within 24 hours of onset. Open-label, blinded-end point, bayesian-adaptive randomized trial with interim analyses for early stopping (futility or success) or population enrichment, which was conducted at 47 US academic and community-based stroke thrombectomy centers. Three hundred patients presenting within 24 hours with anterior-circulation, large-vessel occlusion and large infarct on noncontrast CT scan, with Alberta Stroke Program Early CT Scores of 2 to 5, were randomized to undergo thrombectomy or usual care. Enrollment occurred July 16, 2019 to October 17, 2022; final follow-up, January 25, 2023. The intervention patients (n = 152) underwent endovascular treatment using standard thrombectomy devices and usual medical care. Control patients (n = 148) underwent usual medical care alone. The primary efficacy end point was improvement in 90-day functional outcome measured using mean utility-weighted modified Rankin Scale (UW-mRS) scores (range, 0 [death or severe disability] to 10 [no symptoms]; minimum clinically important difference, 0.3). A bayesian model determined the posterior probability that the intervention would be superior to usual care; statistical significance was a 1-sided posterior probability of .975 or more. The primary adverse event end point was 90-day mortality; secondary adverse event end points included symptomatic intracranial hemorrhage and radiographic intracranial hemorrhage. The trial enrolled 300 patients (152 intervention, 148 control; 138 females [46%]; median age, 67 years), without early stopping or enrichment; 297 patients completed the 90-day follow-up. The mean (SD) 90-day UW-mRS score was 2.93 (3.39) for the intervention group vs 2.27 (2.98) for the control group with an adjusted difference of 0.63 (95% credible interval [CrI], -0.09 to 1.34; posterior probability for superiority of thrombectomy, .96). The 90-day mortality was similar between groups: 35.3% (53 of 150) for the intervention group vs 33.3% (49 of 147) for the control group. Six of 151 patients (4.0%) in the intervention group and 2 of 149 (1.3%) in the control group experienced 24-hour symptomatic intracranial hemorrhage. Fourteen patients of 148 (9.5%) in the intervention group vs 4 of 146 (2.7%) in the control group experienced parenchymal hematoma type 1 hemorrhages; 14 (9.5%) in the intervention group vs 5 (3.4%) in the control group experienced parenchymal hematoma type 2 hemorrhages; and 24 (16.2%) in the intervention group vs 9 (6.2%) in the control group experienced subarachnoid hemorrhages. Among patients with a large infarct on noncontrast CT within 24 hours, thrombectomy did not demonstrate improvement in functional outcomes. But the width of the credible interval around the effect estimate includes the possibility of both no important effect and a clinically relevant benefit, so the potential role of thrombectomy with this imaging approach and time window will likely require additional study. ClinicalTrials.gov Identifier: NCT03805308.

Acquisition of Prehospital Stroke Severity Scale is associated with shorter door-to-puncture times in patients with prehospital notifications transported directly to a thrombectomy center

BackgroundWe sought to identify systemic factors influencing door-to-puncture times (DTP) among patients with pre-arrival notifications presenting directly to a comprehensive stroke center (CSC) and undergoing emergent mechanical thrombectomy (MT).MethodsIn this...

Cost‐Effectiveness of Prehospital Ambulance Helicopter Transportation of Patients With Presumed Stroke in the Era of Mechanical Thrombectomy

Background Mechanical thrombectomy has emerged as standard of care in treatment of patients with acute ischemic stroke attributable to large‐vessel occlusion. Efforts to reduce the time from symptom onset to treatment initiation remain critically important to improve functional outcomes in patients treated with either intravenous thrombolysis, mechanical thrombectomy, or both. The use of ambulance helicopters in prehospital acute stroke care could potentially reduce symptom onset to treatment time to mechanical thrombectomy. This study aims to optimize the use of ambulance helicopters in prehospital transportation of patients with presumed acute stroke attributable to large‐vessel occlusion given economic constraints in health care budget. Methods By means of an economic model within a decision‐analytical framework, this study evaluates the cost‐effectiveness of complementary ambulance helicopters compared with road ambulances only for prehospital acute transportation of patients with presumed stroke and potential eligibility for mechanical thrombectomy, in regard to the number and locations of ambulance helicopters in Sweden. Results A single, optimally located complementary ambulance helicopter was cost‐effective compared with road ambulances only. The most cost‐effective solution in the base‐case scenario with the current 8 thrombectomy centers comprised 13 optimally located helicopters. It reduced mean onset to treatment time with intravenous thrombolysis and onset to treatment time with mechanical thrombectomy by 7.9 and 32.1 minutes, respectively, and produced health gains equal to 91 quality‐adjusted life‐years per year. When the willingness to pay per quality‐adjusted life‐years gained was set at Euro (EUR) 80 000, the incremental net monetary benefit per patient reached EUR 2240. The solution with 13 optimally located helicopters prevailed as the most cost‐effective in the extended scenario analysis with 11 thrombectomy centers, reaching an estimated incremental net monetary benefit per patient at EUR 1754. Furthermore, mean incremental net monetary benefit per patient reached global maximum (EUR 6046) at the geodesic distance of 165.2 km between patient location and the nearest thrombectomy center in the base‐case scenario, and at 238.5 km in the extended scenario with an estimated incremental net monetary benefit per patient at EUR 7994. Conclusion This study demonstrates the cost‐effectiveness of ambulance helicopters as a complementary mode of transportation to road ambulances. The most cost‐effective solution of complementary ambulance helicopters comprises 13 optimally located heliports across Sweden.

Endovascular Thrombectomy With and Without Preceding Thrombolysis in Posterior Circulation Stroke—Insights From STAR

Background Multiple randomized trials could not establish the noninferiority of endovascular thrombectomy (EVT) alone without preceding intravenous thrombolysis (IVT) or superiority of IVT followed by EVT in anterior circulation large‐vessel occlusion stroke. The role of prior IVT in posterior circulation large‐vessel occlusion remains controversial. Methods In this multicenter, retrospective study, patients with stroke with large‐vessel occlusion in the posterior circulation who received EVT alone or with IVT were selected from the stroke thrombectomy and aneurysm registry between 2013 and 2022. Effects of IVT followed by thrombectomy on favorable functional outcome (defined as modified Rankin scale≤3 at 90 days) and safety were investigated using multivariable logistic and linear regression models. Results Of the 588 included patients, 67% (n = 394) were treated with EVT alone and 29% (n = 170) with EVT after IVT, and 4% (n = 24) have missing values on this variable. Controlling for multiple confounding factors, IVT was not associated with a higher likelihood of favorable functional outcome at 90 days (odds ratio, 1.04 [95% CI, 0.52–2.09; P = 0.901). Thrombectomy alone did not show any safety advantages compared with those receiving IVT. Conclusion Similar functional outcomes and complication rates were seen in patients with posterior circulation large‐vessel occlusion treated with EVT alone versus EVT after IVT. Further prospective studies are required to determine the utility of IVT in posterior circulation stroke, especially in patients being directly admitted to thrombectomy centers.

Potential effects of a mobile stroke unit on time to treatment and outcome in patients treated with thrombectomy or thrombolysis: A Danish-German cross-border analysis.

A mobile stroke unit (MSU) reduces delays in stroke treatment by allowing thrombolysis on board and avoiding secondary transports. Due to the beneficial effect in comparison to conventional emergency medical services, current guidelines recommend regional evaluation of MSU implementation. In a descriptive study, current pathways of patients requiring a secondary transport for mechanical thrombectomy were reconstructed from individual patient records within a Danish (n = 122) and an adjacent German region (n = 80). Relevant timestamps included arrival times (on site, primary hospital, thrombectomy centre) as well as the initiation of acute therapy. An optimal MSU location for each region was determined. The resulting time saving was translated into averted disability-adjusted life years (DALYs). For each region, the optimal MSU location required a median driving time of 35 min to a stroke patient. Time savings in the German region (median [Q1; Q3]) were 7 min (-15; 31) for thrombolysis and 35 min (15; 61) for thrombectomy. In the Danish region, the corresponding time savings were 20 min (8; 30) and 43 min (25; 66). Assuming 28 thrombectomy cases and 52 thrombolysis cases this would translate to 9.4 averted DALYs per year justifying an annual net MSU budget of $0.8M purchasing power parity dollars (PPP-$) in the German region. In the Danish region, the MSU would avert 17.7 DALYs, justifying an annual net budget of PPP-$1.7M. The effects of an MSU can be calculated from individual patient pathways and reflect differences in the hospital infrastructure between Denmark and Germany.

An optimization model for reducing thrombectomy center rotations while maintaining medical accessibility

Background/purposeThis study addresses the delicate balance between healthcare personnel burnout and medical accessibility in the context of endovascular thrombectomy (EVT) services in urban areas. We aimed to determine the minimum number of hospitals providing EVT on rotation each day without compromising patient access. MethodsEmploying an optimization model, we developed shift schedules based on patient coverage rates and volumes during the pre-pandemic (2016–2018) and pandemic (2019–2021) periods. Starting with a minimum of two hospitals on duty per day, we gradually increased to a maximum of eight. Patient coverage rates, defined as the proportion of patients meeting bypass criteria and transported to rotating hospitals capable of EVT, were the primary outcomes. Sensitivity analyses explored the impact of varying patient transport intervals and accumulating patients over multiple years. ResultsResults from 7024 patient records revealed patient coverage rates of 92.5% (standard deviation [SD] 2.8%) during the pre-pandemic and 91.4% (SD 2.8%) during the pandemic, with at least two rotating hospitals daily. No significant differences were observed between schedules based on the highest patient volume and coverage rate months. A patient coverage rate of 98.99% was achieved with four rotating hospitals per day during the pre-pandemic period, with limited improvement beyond this threshold. Changing patient transport intervals and accumulating patients over six years (p = 0.83) had no significant impact on coverage rates. ConclusionOur optimization model supports reducing the number of daily rotating hospitals by half while preserving a balance between patient accessibility and alleviating strain on medical teams.

Large vessel occlusive stroke with milder baseline severity shows better collaterals and reduced harm from thrombectomy transfer delays.

Patients with large vessel occlusion (LVO) stroke presenting with milder baseline clinical severity are common and require endovascular thrombectomy. However, such patients are difficult to recognize using pre-hospital severity-based triage tools and therefore are likely to require a secondary inter-hospital transfer if transported to a non-thrombectomy center. Given the potential for milder severity to represent better underlying cerebrovascular collateral circulation, it is unknown whether transfer delays are still associated with poorer post-stroke outcomes in this patient group. We primarily aimed to examine whether the harmful effect of inter-hospital transfer delay for thrombectomy was different for LVO patients with mild or severe deficits. Secondarily, we also investigated whether imaging markers of collateral circulation were different between severity groups. Registry data from two large Australian thrombectomy centers were used to identify all directly presenting and secondarily transferred LVO patients undergoing thrombectomy, divided into those with lower (NIHSS < 10) and higher (NIHSS ⩾ 10) baseline deficits. The primary outcome was the functional independence or return to baseline defined as modified Rankin Scale 0-2 or baseline at 90 days. Patients with complete baseline CT-perfusion data were analyzed for imaging markers of collateral circulation by baseline severity group. A total of 1210 LVO patients undergoing thrombectomy were included, of which 273 (22.6%) had lower baseline severity. Despite similar thrombolysis and recanalization rates, transferred patients had lower odds of achieving the primary outcome compared to the primary presentation to a thrombectomy center, where baseline severity was higher (adjusted odds ratio (aOR) 0.759 (95% CI 0.576-0.999)), but not when severity was lower (aOR 1.357 (95% CI 0.764-2.409), p-interaction = 0.122). In the imaging analysis of 436 patients, those with milder severity showed smaller median ischemic core volumes (12.6 (IQR 0.0-17.9) vs 27.5 (IQR 6.5-37.1) mL, p < 0.001)), higher median perfusion mismatch ratio (10.8 (IQR 4.8-54.5) vs 6.6 (IQR 3.5-16.5), p < 0.001), and lower median hypoperfusion intensity ratio (0.25 (IQR 0.18-0.38) vs 0.40 (IQR 0.22-0.57), p < 0.001). Patients receiving secondary inter-hospital transfer for thrombectomy had poorer outcomes compared to those presenting directly to a thrombectomy center if baseline deficits were severe, but this difference was not observed when baseline deficits were milder. This result may potentially be due to our secondary findings of significantly improved collateral circulation markers in lower-severity LVO patients. As such, failure of pre-hospital screening tools to detect lower-severity LVO patients for pre-hospital bypass to a thrombectomy center may not necessarily deleteriously affect outcome. Anonymized data not published within this article will be made available on request from any qualified investigator.

Impact of Direct Transport to Thrombectomy-Capable Center vs. Nearby/Distant Local Stroke Centers on Stroke Outcome in Patients Undergoing Thrombectomy: A Real-Life Study.

Our aim was to compare the stroke outcomes of a direct transfer (DT) to a thrombectomy-capable center vs. initial care at two local stroke centers: a nearby hospital (NH, 36 km) and a distant hospital (DH, 113 km). Patients who underwent a mechanical thrombectomy were analyzed (February 2017-October 2021), and the outcome was considered favorable if the modified Rankin scale (mRS) score was ≤ 2 at three months. A total of 300 patients were included, 55 of which were transferred from the NH and 58 from the DH. There was a difference in the median (IQR) transfer time of 39 min between the hospitals (149 min for the NH vs. 188 min for the DH, p = 0.003). After adjusting for confounding variables, a secondary transfer from the DH, compared to a DT, was associated with a lower functional independence: mRS score ≤ 2 (OR = 0.37, 95% CI = 0.14-0.97, p = 0.043), without significant differences in the mortality between the groups. These differences were not observed in patients from the NH. Conclusions: A secondary transfer from a distant hospital was associated with a poorer functional outcome at 3 months. This unfavorable outcome was not observed among patients transferred from a nearby hospital. These findings highlight the importance of categorizing the suitability of one transfer model over another based on the proximity of hospitals to the thrombectomy center, but also in accordance with organizational and geographic characteristics that vary within each health region.

Effect of concomitant usage of alteplase and mechanical thrombectomy for M1 middle cerebral artery occlusion on clinical outcome: a retrospective analysis of 457 patients from two centers.

Endovascular thrombectomy (EVT) and concomitant usage of intravenous alteplase (alteplase) in large vessel occlusion stroke may produce unwanted excess intracerebral hemorrhage (ICH). Whether this applies specifically to isolated occlusion of the M1 segment of the middle cerebral artery (MCA) is unknown. A retrospective study from two tertiary thrombectomy centers. ICH was determined according to Heidelberg Bleeding Classification (HBC). Factors associated with the occurrence of ICH in EVT alone vs. EVT with alteplase were evaluated using logistic regression analysis. Factors related to the clinical outcome as determined with a modified Rankin scale (mRS) were investigated with univariate and adjusted multivariate logistic regression analysis. The interaction between clinical variables and the usage of alteplase on the occurrence of ICH was evaluated. Any ICH occurred in 156/457 (34.1%) patients Class 1a bleeding in 37 (8.1%), type 2 in 45 (9.8%) Class 1c in 22 (4.8%), Class 2 in 25 (5.5%), and Class 3 (extraparenchymal) in 27 (5.9%). ICH occurred in similar frequency between alteplase-treated patients vs. EVT alone (85/262 [32%] vs. 71/195 [36%]; OR 1.19 (95% CI 0.81-1.76). After adjustment, odds for clinical outcome were lower in ICH patients (OR 0.44 [95% CI 0.25-0.74]), p = 0.002). Higher ICH rate was associated with more EVT steps (p for interaction -0.005), and usage of only stent-retriever (p for interaction =0.005). Utilization of alteplase alongside EVT for MCA M1 occlusion did not result in excessive ICH occurrences or clinical deterioration.

Stroke Coordinator Developmental Needs Around the Globe: An MT - ANVC International Survey

Background Stroke Coordinators (SC) should be commonly utilized in Stroke Centers to ensure provision of evidence-based services, oversee quality improvement, and support interdisciplinary and community education. Mission Thrombectomy (MT) partnered with the Association of Neurovascular Clinicians (ANVC) to understand how SCs are utilized outside the US and to compare developmental needs for this role across the world. Methods A brief survey was constructed to capture information about the use of SCs and their duties, including personnel utilized to execute the role and areas deemed important for role development. The survey was disseminated through the MT and ANVC membership rosters; returned data were assembled in SPSS (version 25) and analyzed using descriptive and X2statistical tests.Results A total of 74 surveys were returned from 17 countries (63% USA). Survey responders were SCs (41%), physicians (39%), program managers (19%) and advanced practice providers (APPs) (1%); 47% were from thrombectomy centers. The SC role was filled at 92% of centers; MDs more commonly assumed the SC role outside the USA (63%), versus registered nurses in the USA (95%; X2=25.2, p&lt;0.001). Of the 70% of respondents interested in receiving assistance from MT and ANVC for SC development resources, the functions deemed most important were “quality improvement” and “emergency medical service personnel education” for USA respondents (36%), whereas “development of stroke systems of care” (60%) and “government policy change” (40%) were ranked highest outside the USA. Conclusions Non-USA Stroke Centers have significant SC development needs that differ markedly from those within the USA. MT provides an important platform to engage international programs and the MT/ANVC partnership is well positioned to further stroke nursing care and SC development globally.

Outcome of endovascular stroke therapy in a large mandatory stroke-registry

BackgroundEndovascular stroke treatment (EST) has become the standard treatment for patients with stroke due to large vessel occlusion, especially in earlier time windows. Only few data from population-based registries on effectiveness of EST have been published.MethodsBaden–Wuerttemberg is the third largest state in Germany in terms of area and population and has a structured stroke concept since 1998 which includes mandatory collection of quality assurance data. In 2018 and 2019, 3820 of 39,168 ischemic stroke patients (9.8%) were treated by EST (age median 78 y, NIHSS median 14). We analyzed the clinical outcome of these patients determined with the modified Rankin Scale (mRS) at discharge from the hospital or with the initiation of palliative therapy using logistic regression analysis with adjustment for the mRS at admission, additive IVT, age, and NIHSS.ResultsThe probability of an excellent clinical outcome (mRS 0 or 1 at discharge) and for a good clinical outcome (mRS 0–2) were significantly higher in EST-patients (odds-ratio (OR) 1.27; 95% confidence interval (95% CI) 1.13–1.43, and OR of 1.15 (95% CI 1.04–1.28). Also, the regression model showed an advantage for EST-patients with less frequent ‘decision for palliative care’ (OR 0.87; 95% CI 0.78–0.98). Sensitivity analysis adjusting for intracranial vessel occlusion as further factor showed similar results.ConclusionOur data suggest that EST can be of benefit also for an area-wide unselected stroke population, in a large German federal state with sometimes long distance to the next thrombectomy center.

Abstract 065: Advancing Stroke Care Services through Collaborative Efforts: Mission Thrombectomy Surveys of Slovenia

Introduction Acute stroke care must always be improved because stroke is still a leading cause of mortality and adult‐onset disability. The Mission Thrombectomy Slovenia Regional Committee (RC) has established a forward‐thinking initiative to improve stroke treatment services in response to this challenge. With a focus on showcasing the complete picture of stroke systems and identifying areas for improvement to achieve better patient outcomes and increase accessibility to mechanical thrombectomy (MT) treatments in Slovenia, this partnership aims to conduct extensive surveys, analyses, and propose a roadmap to overcome obstacles and optimize the stroke care ecosystem. The SVIN Mission Thrombectomy Slovenia Regional committee (RC) comprises distinguished experts, including Zoran Miloševič as Neurointerventional co‐chair, and Senta Frol and Janja Pretnar Oblak as stroke co‐chairs, respectively, and Igor Rigler as ER co‐chair, whose expertise and collaborative efforts form the backbone of this initiative. Methods As an initial step, we have commenced surveys with UMC Ljubljana, Slovenia. UMC Ljubljana, as a Mechanical Thrombectomy Center, has demonstrated consistent growth in the number of procedures conducted. There is a projection of 180 procedures in 2023, an increase from 135 in 2021 and 109 in 2022. The increased projected procedure volume indicates the hospital's proactive approach in delivering cutting‐edge stroke treatments. A pivotal aspect of UMC Ljubljana's stroke care model lies in its advanced imaging capabilities, including CTA/CTP and MRI/MRP, enabling precise and swift diagnoses, fostering better treatment planning, and optimizing patient outcomes. Furthermore, the presence of a well‐equipped Angio suite, staffed with competent MT operators, ensures seamless execution of interventional procedures. Results The collaboration's future vision involves conducting surveys and analyzing data to identify barriers to MT access, streamlining the patient journey, and improving overall stroke care efficiency. The ongoing efforts of building a Stroke Registry at UMC Ljubljana will enable in‐depth analysis, fostering continuous evolution in stroke care practices. Additionally, investments in Intermediate/Step down care and Telemetry beds will play a vital role in strengthening the continuum of care, enabling smooth patient transitions, and reducing potential delays in treatment. Healthcare practitioners' awareness for stroke triage and Physician Training emerge as the most impactful Thrombectomy Patient Health Initiatives. By prioritizing these initiatives, UMC Ljubljana and Mission Thrombectomy aim to foster early recognition, prompt treatment, and streamlined care for stroke patients. Conclusion In conclusion, the collaborative efforts of UMC Ljubljana and Mission Thrombectomy Slovenia RC are poised to elevate stroke care and MT services through data‐driven analysis and the proposed roadmap. By incorporating future surveys and continuous improvement strategies, the collaboration aims to create a paradigm shift in stroke care, ensuring accessible, efficient, and optimized services to patients in need. Moving forward, we will continue to conduct surveys within the current EVT and stroke centers examining the calculated MT Operator availability (MTOA), MT Center availability (MTCA), and MT Access Rate (MTAR) scores to identify the current barriers to increase access to mechanical thrombectomy.

Differential thrombectomy utilization across hospital classifications in the United States

ObjectivesTo determine hospital-level factors associated with thrombectomy uptake. Materials and methodsThe 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. ResultsBetween 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. ConclusionsBetween 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.

Intravenous thrombolysis prior to endovascular thrombectomy in elderly stroke patients: An analysis of the National Inpatient Sample database

BackgroundThe effectiveness of intravenous thrombolysis (IVT) prior to endovascular thrombectomy (EVT), also termed bridging thrombolysis, remains uncertain, and there is limited data on its use for elderly patients who may be more prone to hemorrhagic complications. MethodsThis was a large-scale cross-sectional study of the 2016–2020 National Inpatient Sample (NIS) database. Adult EVT patients presenting directly to thrombectomy centers without prior treatment were identified. Patient demographics, stroke risk factors, stroke etiology, medical comorbidities, and IVT treatment were recorded. Outcomes of interest include in-hospital mortality, rates of discharge to home, and hemorrhagic complications. Multivariable logistic regression models were used to account for possible confounders. Results35,735 EVT patients presenting directly to thrombectomy centers without prior thrombolytic treatment were identified. 32.5% (11,630 patients) were treated with bridging thrombolysis. Overall, bridging thrombolysis was significantly associated with lower rates of in-hospital mortality (8.8% vs. 11.2%, p < 0.001) and higher rates of discharge to home (38.0% vs. 28.7%, p < 0.001). IVT's association with lower odds of in-hospital mortality was significantly attenuated with increasing age (interaction p = 0.038), and there was no significant association between IVT treatment with in-hospital mortality for patients 80 years or older (OR 0.99 [95%CI 0.72–1.35], p = 0.94). Similarly, older age significantly amplifies the hemorrhagic risk associated with bridging thrombolysis (interaction p = 0.006). When considering only patients without hemorrhagic complications, age does not significantly modulate IVT's association with patient outcomes. ConclusionsBridging thrombolysis may be associated with better outcomes; however, its benefit may be diminished among elderly patients due to higher rates of hemorrhagic complications.

Virtual reality simulation training in stroke thrombectomy centers with limited patient volume-Simulator performance and patient outcome.

Virtual reality simulation training may improve the technical skills of interventional radiologists when establishing endovascular thrombectomy at limited-volume stroke centers. The aim of this study was to investigate whether the technical thrombectomy performance of interventional radiologists improved after a defined virtual reality simulator training period. As part of the quality surveillance of clinical practice, we also assessed patient outcomes and thrombectomy quality indicators at the participating centers. Interventional radiologists and radiology residents from three thrombectomy-capable stroke centers participated in a five months thrombectomy skill-training curriculum on a virtual reality simulator. The simulator automatically registered procedure time, the number of predefined steps that were correctly executed, handling errors, contrast volume, fluoroscopy time, and radiation dose exposure. The design was a before-after study. Two simulated thrombectomy cases were used as pretest and posttest cases, while seven other cases were used for training. Utilizing the Norwegian Stroke Register, we investigated clinical results in thrombectomy during the study period. Nineteen interventional radiologists and radiology residents participated in the study. The improvement between pretest and posttest cases was statistically significant for all outcome measures in both simulated cases, except for the contrast volume used in one case. Clinical patient outcomes in all three centers were well within the recommendations from multi-society consensus guidelines. Performance on the virtual reality simulator improved after training. Virtual reality simulation may improve the learning curve for interventional radiologists in limited-volume thrombectomy centers. No correlation alleged, the clinical data indicates that the centers studied performed thrombectomy in accordance with guideline-recommended standards.

Thrombolysis in Patients With Large‐Vessel Occlusion Directly Admitted or Transferred to a Thrombectomy Center: A Population‐Based Study

Background Our goal is to evaluate whether the administration of thrombolytic treatment has varying effects on clinical and radiological outcomes in patients with large‐vessel occlusion stroke, based on the type of stroke center where the treatment was given (thrombectomy‐capable center versus local stroke center). Methods We included patients with an acute ischemic large‐vessel occlusion stroke who were directly admitted to thrombectomy‐capable centers and treated with endovascular thrombectomy, or were transferred from local stroke centers as thrombectomy candidates, in Catalonia, Spain, between 2017 and 2021. The primary outcome was the shift analysis on the modified Rankin scale score at 90 days. Secondary outcomes included death at 90 days and the rate of parenchymal hemorrhage and successful reperfusion. Inverse‐probability weighting clustered at the type of stroke center was used to estimate the effects. Results The analysis included 2268 patients directly admitted to thrombectomy‐capable centers, of whom 975 (49%) were treated with thrombolysis, and 938 patients transferred from local stroke centers, of whom 580 (66%) were treated with thrombolysis and 616 (67%) were treated with thrombectomy. Mean age was 72 (SD ±13) years, median National Institute of Health Stroke Scale score was 17 (interquartile range, 12–21), and 1363 patients were women (48%). Patients treated with intravenous thrombolysis were younger, had shorter time from onset to first image, higher Alberta Stroke Program Early Computed Tomography Score, and lower rates of wake‐up stroke, atrial fibrillation, and anticoagulation intake. Patients treated with thrombolysis had better functional outcome at 90 days, with no difference between patients directly admitted to thrombectomy‐capable centers (adjusted common odds ratio [acOR], 1.50 [95% CI, 1.24–1.81]) and patients transferred from local stroke centers (acOR, 1.44 [95% CI, 1.04–2.01]). Patients treated with intravenous thrombolysis had lower death rate, higher rate of parenchymal hematoma, and similar rate of successful reperfusion, with no difference according to type of center ( P interaction &gt;0.1). Conclusion Administration of intravenous thrombolysis in patients with a large‐vessel stroke with intention of thrombectomy was associated with lower degrees of disability, lower death rate, and higher rates of parenchymal hematoma both in thrombectomy‐capable centers and in local stroke centers.

Decline of thrombolysis rates before endovascular therapy in patients with acute anterior circulation large vessel occlusion ischemic stroke: A multicenter analysis from the German Stroke Registry.

In recent years, the role of intravenous thrombolysis (IVT) before endovascular stroke treatment (EVT) has been discussed intensively. Whether the discussion was accompanied by changing rates of bridging IVT is unknown. Data were extracted from the prospectively maintained German Stroke Registry, including patients treated with EVT at one of 28 stroke centers in Germany between 2016 and 2021. Primary outcome parameters were the rate of bridging IVT (a) in the entire registry cohort and (b) in patients without formal contraindications to IVT (i.e. recent oral anticoagulants, time window ⩾4.5 h, extensive early ischemic changes) adjusted for demographic and clinical confounders. 10,162 patients (52.8% women, median age 77 years, median National Institutes of Health Stroke Scale score 14) were analyzed. In the entire cohort, the rate of bridging IVT decreased from 63.8% in 2016 to 43.6% in 2021 (average absolute annual decrease 3.1%, 95% CI 2.4%-3.8%), while the proportion of patients with at least one formal contraindication increased by only 1.2% annually (95% CI 0.6%-1.9%). Among 5460 patients without record of formal contraindications, the rate of bridging IVT decreased from 75.5% in 2016 to 63.2% in 2021 and was significantly associated with admission date in a multivariable model (average absolute annual decrease 1.4%, 95% CI 0.6%-2.2%). Clinical factors associated with lower odds of bridging IVT included diabetes mellitus, carotid-T-occlusion, dual antiplatelet therapy, and direct admission to a thrombectomy center. We observed a substantial decline in bridging IVT rates independent of demographic confounders and not explained by an increase in contraindications. This observation deserves further exploration in independent populations.

A Telestroke Nurse and Neuroradiologist Model for Extended Window Code Stroke Triage.

BACKGROUND: Distinguishing features of our stroke network include routine involvement of a telestroke nurse (TSRN) for code stroke activations at nonthrombectomy centers and immediate availability of neuroradiologists for imaging interpretation. On May 1, 2021, we implemented a new workflow for code stroke activations presenting beyond 4.5 hours from last known well that relied on a TSRN supported by a neuroradiologist for initial triage. Patients without a target large vessel occlusion (LVO) were managed without routine involvement of a teleneurologist, which represented a change from the preimplementation period. METHODS: We collected data 6 months before and after implementation of the new workflow. We compared preimplementation process metrics for patients managed with teleneurologist involvement with the postimplementation patients managed without teleneurologist involvement. RESULTS: With the new workflow, teleneurologist involvement decreased from 95% (n = 953) for patients presenting beyond 4.5 hours from last known well to 37% (n = 373; P < .001). Compared with patients in the preimplementation period, postimplementation patients without teleneurologist involvement experienced less inpatient hospital admission and observation (87% vs 90%; unadjusted P = .038, adjusted P = .06). Among the preimplementation and postimplementation admitted patients, there was no statistically significant difference in follow-up neurology consultation or nonstroke diagnoses. A similar percentage of LVO patients were transferred to the thrombectomy center (54% pre vs 49% post, P = .612), whereas more LVO transfers in the postimplementation cohort received thrombectomy therapy (75% post vs 39% pre, P = .014). Among LVO patients (48 pre and 41 post), no statistical significance was observed in imaging and management times. CONCLUSION: Our work shows the successful teaming of a TSRN and a neuroradiologist to triage acute stroke patients who present beyond an eligibility window for systemic thrombolysis, without negatively impacting care and process metrics. This innovative partnering may help to preserve the availability of teleneurologists by limiting their involvement when diagnostic imaging drives decision making.

Abstract TMP54: Increased Thrombectomy Time Saving From Melbourne Mobile Stroke Unit Operation During Covid-19 Pandemic

Introduction: Mobile stroke units (MSU) have demonstrated major time savings for thrombolysis but mixed evidence for endovascular thrombectomy (EVT). COVID-19 precautions have dramatically slowed EVT workflows across Australia and we therefore aimed to examine the effect of the Melbourne MSU on thrombectomy times before and during the current pandemic. Methods: Patients receiving EVT facilitated by the Melbourne MSU from 2017-2021 were compared to non-MSU patients (metropolitan direct and secondary transfer for EVT) admitted to the largest Melbourne EVT centre. Quantile regression analysis was used to calculate the median time difference (50 th quantile) between MSU and non-MSU patients before and during the pandemic, grouped by patients within an EVT centre ambulance catchment or those outside (who either received inter-hospital transfer or MSU-facilitated bypass to an EVT centre). Results: A total of 402 patients (112 MSU) were included. Pre-pandemic, no reduction in dispatch to arterial access time was seen for MSU patients within an EVT centre catchment (median 11min slower, p=0.38). However, a significant time saving was observed during the pandemic (median 29 min faster, p&lt;0.001, p-interaction=0.0065). MSU care reduced hospital arrival to arterial access time by median 19min pre-pandemic vs 40 min during the pandemic, p-interaction&lt;0.001). The pandemic did not alter MSU-related time savings for patients located outside of an EVT centre catchment. Conclusions: Melbourne MSU facilitation of EVT during the COVID-19 pandemic resulted in greater time savings for patients located close to a thrombectomy centre, while substantial time savings were maintained for those needing bypass from the local non-EVT hospital. This suggests that MSU operation enables streamlined EVT workflows during the pandemic by providing early pre-hospital notification and interventional angiography activation.

Abstract TMP42: 911 Continuation Of Care Protocol Reduces Door In, Door Out Time For Transfer Patients With Emergent Large Vessel Occlusion

Background: Rapid reperfusion with mechanical thrombectomy (MT) for large vessel occlusion leads to an improvement functional independence. Prolonged transfers from non-interventional to interventional hospitals are a major cause of delay in reperfusion times. The use of the 911 EMS system has accelerated myocardial infarction transfers and potentially could accelerate stroke transfers, but their effect on stroke transfer times have not been well delineated. Methods: In our 14- hospital system, transfers from non-interventional facilities to intrasystem or intersystem interventional capable facilities typically utilize a centralized group of nurses who arrange for contracted ambulance pickup (CAP). However, in San Bernardino County (CA), 911 EMS continuation of care (COC) is an alternative method available for transferring MT patients. Under the COC process, the sending hospital calls 911 and the nearest EMS ambulance responds to transport the patient to the thrombectomy center. We compared Door In, Door Out (DIDO) times between the COC vs CAP protocol between January 1, 2021 and January 30, 2022. Demographic and clinical variables were compared using t-test for continuous variables and chi-square for categorical variables. Results: Among 112 patients, 26 (23%) were transferred by COC and 86 (77%) by CAP. COC and CAP patients did not significantly differ in age ( Mdn 71 {IQR:22} vs Mdn 72 {IQR:20.5}, p = 0.81), sex (46% vs 36% female, p = 0.92), or presenting NIHSS ( Mdn 14 {IQR:12} vs Mdn 13 {IQR:14}, p = 0.62). Rates of thrombolytic started at the sending hospital were 54% (14/26) in COC patients and 48% (41/86) in ETAP patients (p = 0.58). DIDO time was faster in the COC group, ( Mdn 58 minutes {IQR 44-73} vs Mdn 94 minutes {IQR 79-142}, p&lt;0.01). In contrast, there was a significant difference in DIDO time between intrasystem transfers by COC ( Mdn 69.5 min. {IQR: 48.5-115.5} and transfers out of system by COC ( Mdn 66 min.{IQR: 53-88}, p=0.20), suggesting that there was no special advantage for intrasystem transfers over intersystem transfers. Conclusion: Using the 911 EMS system for interfacility transport of patients eligible for MT reduced DIDO time at the sending hospital by over 40 minutes, which may contribute to improved functional outcome.