Thrombectomy-capable Stroke Centers Research Articles

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

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. 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. 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. 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.

Time to Treatment With Intravenous Thrombolysis Before Thrombectomy and Functional Outcomes in Acute Ischemic Stroke

The benefit of intravenous thrombolysis (IVT) for acute ischemic stroke declines with longer time from symptom onset, but it is not known whether a similar time dependency exists for IVT followed by thrombectomy. To determine whether the benefit associated with IVT plus thrombectomy vs thrombectomy alone decreases with treatment time from symptom onset. Individual participant data meta-analysis from 6 randomized clinical trials comparing IVT plus thrombectomy vs thrombectomy alone. Enrollment was between January 2017 and July 2021 at 190 sites in 15 countries. All participants were eligible for IVT and thrombectomy and presented directly at thrombectomy-capable stroke centers (n = 2334). For this meta-analysis, only patients with an anterior circulation large-vessel occlusion were included (n = 2313). Interval from stroke symptom onset to expected administration of IVT and treatment with IVT plus thrombectomy vs thrombectomy alone. The primary outcome analysis tested whether the association between the allocated treatment (IVT plus thrombectomy vs thrombectomy alone) and disability at 90 days (7-level modified Rankin Scale [mRS] score range, 0 [no symptoms] to 6 [death]; minimal clinically important difference for the rates of mRS scores of 0-2: 1.3%) varied with times from symptom onset to expected administration of IVT. In 2313 participants (1160 in IVT plus thrombectomy group vs 1153 in thrombectomy alone group; median age, 71 [IQR, 62 to 78] years; 44.3% were female), the median time from symptom onset to expected administration of IVT was 2 hours 28 minutes (IQR, 1 hour 46 minutes to 3 hours 17 minutes). There was a statistically significant interaction between the time from symptom onset to expected administration of IVT and the association of allocated treatment with functional outcomes (ratio of adjusted common odds ratio [OR] per 1-hour delay, 0.84 [95% CI, 0.72 to 0.97], P = .02 for interaction). The benefit of IVT plus thrombectomy decreased with longer times from symptom onset to expected administration of IVT (adjusted common OR for a 1-step mRS score shift toward improvement, 1.49 [95% CI, 1.13 to 1.96] at 1 hour, 1.25 [95% CI, 1.04 to 1.49] at 2 hours, and 1.04 [95% CI, 0.88 to 1.23] at 3 hours). For a mRS score of 0, 1, or 2, the predicted absolute risk difference was 9% (95% CI, 3% to 16%) at 1 hour, 5% (95% CI, 1% to 9%) at 2 hours, and 1% (95% CI, -3% to 5%) at 3 hours. After 2 hours 20 minutes, the benefit associated with IVT plus thrombectomy was not statistically significant and the point estimate crossed the null association at 3 hours 14 minutes. In patients presenting at thrombectomy-capable stroke centers, the benefit associated with IVT plus thrombectomy vs thrombectomy alone was time dependent and statistically significant only if the time from symptom onset to expected administration of IVT was short.

Abstract 22: Time to Treatment and the Effect of Intravenous Thrombolysis Before Thrombectomy: An Individual Participant Data Meta-Analysis

Introduction: The benefit of intravenous thrombolysis for acute ischemic stroke declines with longer time from symptom onset. It is not known whether a similar time-dependent treatment effect modification of intravenous thrombolysis (IVT) is present in patients undergoing thrombectomy. Methods: Individual participant data meta-analysis from six randomized controlled trials comparing IVT plus thrombectomy vs thrombectomy alone. Primary analysis was performed testing for heterogeneity of the treatment effect. We estimated the effect of onset-to-expected-IVT times on the association between allocated treatment (intravenous thrombolysis plus thrombectomy vs thrombectomy alone) and disability at 3 months (modified Rankin scale, mRS). Results: In 2313 participants (IVT plus thrombectomy [n = 1160]; thrombectomy alone [n = 1153]; median age, 71 years, IQR 62-78 years; 44.3% female), the median onset-to-expected-IVT time was 2h 28min (IQR, 1h 46min to 3h 17min). We observed a statistically significant interaction between onset-to-expected-IVT times and treatment group effect (pinteraction=0.02), with the treatment effect of IVT plus thrombectomy vs thrombectomy alone declining over time (e.g., common adjusted Odds Ratio for a one-step mRS shift toward improvement 1.49, 95%CI 1.13-1.96 at 1h; 1.25, 95% CI 1.04-1.49 at 2h; 1.04, 95% CI 0.88-1.23 at 3h). If treated before 2h 20min after symptom onset, participants allocated to IVT plus thrombectomy were significantly less disabled at 90 days than participants allocated to thrombectomy alone. Conclusions: This individual participant data meta-analysis of patients with ischemic stroke presenting at thrombectomy-capable stroke centers demonstrated time-dependence of the treatment effect of IVT plus thrombectomy vs thrombectomy alone. Intravenous thrombolysis showed clinical benefit if it was administered within 2h 20min after symptom onset.

Thrombectomy in Stroke Patients With Low Alberta Stroke Program Early Computed Tomography Score: Is Modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3 Superior to mTICI 2b?

Outcomes following mechanical thrombectomy (MT) are strongly correlated with successful recanalization, traditionally defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b. This retrospective cohort study aimed to compare the outcomes of patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS; 2-5) who achieved mTICI 2b versus those who achieved mTICI 2c/3 after MT. This study utilized data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combined databases from 32 thrombectomy-capable stroke centers between 2013 and 2023. The study included only patients with low ASPECTS who achieved mTICI 2b, 2c, or 3 after MT for internal carotid artery or middle cerebral artery (M1) stroke. Of the 10,229 patients who underwent MT, 234 met the inclusion criteria. Of those, 98 (41.9%) achieved mTICI 2b, and 136 (58.1%) achieved mTICI 2c/3. There were no significant differences in baseline characteristics between the two groups. The 90-day favorable outcome (modified Rankin Scale score: 0-3) was significantly better in the mTICI 2c/3 group than in the mTICI 2b group (adjusted odds ratio 2.35; 95% confidence interval [CI] 1.18-4.81; P=0.02). Binomial logistic regression revealed that achieving mTICI 2c/3 was significantly associated with higher odds of a favorable 90-day outcome (odds ratio 2.14; 95% CI 1.07-4.41; P=0.04). In patients with low ASPECTS, achieving an mTICI 2c/3 score after MT is associated with a more favorable 90-day outcome. These findings suggest that mTICI 2c/3 is a better target for MT than mTICI 2b in patients with low ASPECTS.

Performance of Thrombectomy-Capable, Comprehensive, and Primary Stroke Centers in Reperfusion Therapies for Acute Ischemic Stroke: Report From the Get With The Guidelines-Stroke Registry.

The thrombectomy-capable stroke center (TSC) is a recently introduced intermediate tier of accreditation for hospitals at which patients with acute ischemic stroke receive care. The comparative quality and clinical outcomes of reperfusion therapies at TSCs, primary stroke centers (PSCs), and comprehensive stroke centers (CSCs) have not been well delineated. We conducted a retrospective, observational, cohort study from 2018 to 2020 that included patients with acute ischemic stroke who received endovascular thrombectomy (EVT) and intravenous thrombolysis reperfusion therapies at CSCs, TSCs, or PSCs. Participants were recruited from Get With The Guidelines-Stroke registry. Study end points included timeliness of intravenous thrombolysis and EVT, successful reperfusion, discharge destination, discharge mortality, and functional independence at discharge. Among 84 903 patients, 48 682 received EVT, of whom 73% were treated at CSCs, 22% at PSCs, and 4% at TSCs. The median annual EVT volume was 76 for CSCs, 55 for TSCs, and 32 for PSCs. Patient differences by center status included higher National Institutes of Health Stroke Scale score, longer onset-to-arrival time, and higher transfer-in rates for CSCs, TSCs, and PSCs, respectively. In adjusted analyses, the likelihood of achieving the goal door-to-needle time was higher in CSCs compared with PSCs (odds ratio [OR], 1.39 [95% CI, 1.17-1.66]) and in TSCs compared with PSCs (OR, 1.45 [95% CI, 1.08-1.96]). Likewise, the odds of achieving the goal door-to-puncture time were higher in CSCs compared with PSCs (OR, 1.58 [95% CI, 1.13-2.21]). CSCs and TSCs also demonstrated better clinical efficacy outcomes compared with PSCs. The odds of discharge to home or rehabilitation were higher in CSCs compared with PSCs (OR, 1.18 [95% CI, 1.06-1.31]), whereas the odds of in-hospital mortality or discharge to hospice were lower in both CSCs compared with PSCs (OR, 0.87 [95% CI, 0.81-0.94]) and TSCs compared with PSCs (OR, 0.86 [95% CI, 0.75-0.98]). There were no significant differences in any of the quality-of-care metrics and clinical outcomes between TSCs and CSCs. In this study representing national US practice, CSCs and TSCs exceeded PSCs in key quality-of-care reperfusion metrics and outcomes, whereas TSCs and CSCs demonstrated a similar performance. With more than one-fifth of all EVT procedures during the study period conducted at PSCs, it may be desirable to explore national initiatives aimed at facilitating the elevation of eligible PSCs to a higher certification status.

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.

Statewide availability of acute stroke treatment, services, and programs: A survey of North Carolina Hospitals

IntroductionWe conducted a statewide assessment of the availability of stroke treatment, services, and programs in North Carolina (NC) hospitals. We also examined differences in stroke care capabilities between urban, suburban, and rural hospitals and trends over the past 2 decades. MethodsAn electronic survey was distributed to all 111 licensed hospitals in NC. Survey questions asked about stroke center certification status (i.e., standardized levels of stroke care capabilities), diagnostic testing, acute treatments and protocols, and post-acute management. Responses were collected from October 2020-April 2021. Select characteristics were compared to those from prior NC surveys in 1998, 2003, and 2008. ResultsAll 111 hospitals responded to the survey (100% response rate). Among 108 hospitals providing acute stroke care, 12 (11%) were Comprehensive Stroke Centers or Thrombectomy-Capable Stroke Centers, which were all located in urban or suburban areas. While 38% of urban/suburban hospitals were non-certified, 48% of rural hospitals were non-certified. Non-contrast computed tomography (CT), CT angiography, and alteplase treatment were widely available (100%, 95%, and 99%, respectively). Endovascular thrombectomy was solely available in urban/suburban hospitals (29%). Of non-tertiary hospitals, 81% were using telestroke for treatment and transfer decisions. Compared to prior survey results, the availability of CT angiography (76% in 2008 to 95% in 2020-2021), alteplase treatment (69% in 2008 to 99% in 2020-2021), and acute stroke clinical pathways (47% in 2008 to 90% in 2020-2021) increased. However, having an in-house neurologist on staff dropped from approximately 55% in prior surveys to 21% in the current survey. ConclusionsRural NC hospitals were less likely to have advanced diagnostic imaging and treatment capabilities for acute stroke. Temporal trends in staffing with an in-house neurologist and use of telestroke services should be further examined.

‘Drive the doctor’ for endovascular thrombectomy in a rural area: a simulation study

BackgroundPatients who present in a primary stroke center (PSC) with ischemic stroke are usually transferred to a comprehensive stroke center (CSC) in case of a large vessel occlusion (LVO) for endovascular thrombectomy (EVT) treatment, the so-called ‘drip-and-ship’ (DS) model. The ‘drive-the-doctor’ (DD) model modifies the DS model by allowing mobile interventionalists (MIs) to transfer to an upgraded PSC acting as a thrombectomy capable stroke center (TSC), instead of transferring patients to a CSC. Using simulation we estimated time savings and impact on clinical outcome of DD in a rural region.MethodsData from EVT patients in northern Netherlands was prospectively collected in the MR CLEAN Registry between July 2014 - November 2017. A Monte Carlo simulation model of DS patients served as baseline model. Scenarios included regional spread of TSCs, pre-hospital patient routing to ‘the nearest PSC’ or ‘nearest TSC’, MI’s notification after LVO confirmation or earlier prehospital, and MI’s transport modalities. Primary outcomes are onset to groin puncture (OTG) and predicted probability of favorable outcome (PPFO) (mRS 0–2).ResultsCombining all scenarios OTG would be reduced by 28–58 min and PPFO would be increased by 3.4-7.1%. Best performing and acceptable scenario was a combination of 3 TSCs, prehospital patient routing based on the RACE scale, MI notification after LVO confirmation and MI’s transfer by ambulance. OTG would reduce by 48 min and PPFO would increase by 5.9%.ConclusionsA DD model is a feasible scenario to optimize acute stroke services for EVT eligible patients in rural regions. Key design decisions in implementing the DD model for a specific region are regional spread of TSCs, patient routing strategy, and MI’s notification moment and transport modality.

Functional outcome in low-ASPECTS (0-5) acute ischemic stroke treated with mechanical thrombectomy: impact of laterality explored in a single-center study.

There is no consensus regarding the influence of infarct laterality in patients with acute ischemic stroke due to anterior large vessel occlusion (AIS-LVO) treated with mechanical thrombectomy (MT), particularly in low-ASPECT (0-5) patients who were excluded from the initial MT studies and that participated in dedicated randomized-controlled trials that do not consider the side of the occlusion. We aimed to evaluate the role of infarct laterality on the clinical outcome in low-ASPECT AIS patients treated with MT. We retrospectively analyzed our institutional stroke database in our Thrombectomy-Capable Stroke Center (TCSC), including patient characteristics, procedural variables, and outcomes, between January 2015 and January 2022. Patients with acute intracranial ICA and/or proximal MCA occlusions with ASPECT ≤ 5 either on CT or MRI were included and divided into 2 groups according to the location of ischemia. The primary endpoint was a good clinical outcome at 90 days (modified Rankin Scale (mRS) score of 0-3). Between January 2015 and November 2021, 817 MT were performed, of which 82 were low-ASPECT (10.0%): 41 left-sided and 41 right-sided strokes. The rates of good clinical outcome were 30.8% (12/41) for the left-sided group and 43.6% (17/41) for the right-sided group, with a p-value of 0.349. The morality rate showed no significant difference between the two groups: 39.0% (16/41) in the right stroke group and 36.6% (15/41) in the left stroke group. The clinical outcome was not significantly influenced by stroke laterality. The results of this single-center retrospective study indicate either a lack of strength or equal value in performing mechanical thrombectomy regardless of stroke laterality.

Optimized density and locations of stroke centers for improved cost effectiveness of mechanical thrombectomy in patients with acute ischemic stroke

BackgroundDespite the proven cost effectiveness of mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion, treatment within 6 hours from symptom onset remains inaccessible...

The Frequency of CYP2C19 Loss-of-Function Variants in Patients with Non-Cardioembolic Ischemic Stroke or Transient Ischemic Attack in the Dutch Population

Introduction: The CYP2C19 enzyme converts clopidogrel into an active metabolite. Carriers of CYP2C19 loss-of-function (LOF) variants with a history of ischemic stroke or transient ischemic attack (TIA) using clopidogrel may have a higher risk of recurrent stroke. To study the implications of genetic CYP2C19 heterogeneity in treatment of cerebral ischemia, knowledge about the prevalence of CYP2C19 LOF variants within the population is important. We investigated the frequency of CYP2C19 LOF variants in patients with non-cardioembolic ischemic stroke or TIA in the Dutch population. Methods: We performed a single-center observational study with a cross-sectional design in a Dutch thrombectomy-capable stroke center. We included all patients presenting with non-cardioembolic ischemic stroke or TIA. We determined the frequency of CYP2C19 LOF variants in the full cohort. Additionally, we compared the frequency of CYP2C19 LOF variants in two subgroups: patients with first-ever non-cardioembolic ischemic stroke or TIA versus patients with recurrent ischemic stroke or TIA using clopidogrel because of a history of ischemic stroke or TIA. Results: We enrolled 410 patients between January 1, 2021, and July 1, 2021. 109 (26.6%) patients were carriers of CYP2C19 LOF variants. We found no difference in the frequency of CYP2C19 LOF variants between patients with first-ever ischemic stroke or TIA versus patients with recurrent ischemic stroke or TIA using clopidogrel (25.9 vs. 31.9%, respectively, p = 0.31). Discussion and Conclusion: About a quarter of patients with non-cardioembolic ischemic stroke or TIA in the Dutch population carry a CYP2C19 LOF variant. This is lower than estimates found in studies with Asian populations but similar to estimates found among Caucasian patients in other parts of the world.

Clinical outcome, recanalization success, and time metrics in drip-and-ship vs. drive-the-doctor: A retrospective analysis of the HEI-LU-Stroke registry.

This study aimed at comparing clinical outcome, recanalization success and time metrics in the "drip and ship" (DS) vs. "drive the doctor" (DD) concept in a comparable setting. This is a retrospective analysis of thrombectomy registries of a comprehensive stroke center (CSC) and a thrombectomy-capable stroke center (TSC). Patients, who were transferred from the TSC to the CSC, were classified as DS. Patients treated at the TSC by an interventionalist transferred from the CSC were classified as DD. Good outcome was defined as mRS 0-2 or equivalent to premorbid mRS at discharge. Recanalization (TICI 2b-3 or equivalent) and time metrics were compared in both groups. In total, 295 patients were included, of which 116 (39.3%) were treated in the DS concept and 179 (60.7%) in the DD concept. Good clinical outcome was similarly achieved in DS and DD (DS 25.0% vs. DD 31.3%, P = 0.293). mRS on discharge (DS median 4, DD median 4, P = 0.686), NIHSS improvement (DS median 4, DD median 5, P = 0.582) and NIHSS on discharge (DS median 9, DD median 7, P = 0.231) were similar in both groups. Successful reperfusion was achieved similarly in DS (75.9%) and DD as well (81.0%, P = 0.375). Time from onset to reperfusion (median DS 379 vs. DD 286 min, P = 0.076) and time from initial imaging to reperfusion were longer in DS compared to DD (median DS 246 vs. DD 162 min, P < 0.001). The DD concept is time saving while achieving similar clinical outcome and recanalization results.

Abstract Number ‐ 205: Impact of Automated Neuroimaging Triage Platform on Time Metrics at a Thrombectomy Capable Stroke Center

Introduction Rapid detection and appropriate triage of large vessel occlusion (LVO) strokes, upon arrival to a hospital system, is key to achieving better outcomes after endovascular thrombectomy (EVT) mediated recanalization of LVO strokes . Automated neuroimaging analyses has the potential to streamline intra‐ hospital workflow. We aim to study the change in vital intra‐hospital time metrics before and after adoption of an automated neuroimaging triage platform (ANTP). Methods We performed a retrospective analysis of prospectively collected data at our EVT capable stroke center between April 2019 and November 2021. IschemaView’s Rapid software was adopted in October 2020 for triage of stroke patients. Patients treated before were our control cohort and patients treated after were our intervention cohort. Confirmed LVO strokes presenting to our center within 24 hours of stroke onset were included. Results A total of 305 patients were included‐ control (n = 150) and intervention cohort (n = 155). Age (70±15 vs 72 ±15,p = .40), NIHSS score (13 ±8 vs 14 ±7, p = .24), and last‐known‐well to arrival (392 ±464 vs 376 ±427 min, p = .38) were comparable between the two groups. Time from arrival to non‐contrast CT head was also comparable between the two groups (150 ±712 vs 161 ±794, p = .89). Time from non‐contrast CT head to decision to EVT (36 ±54 vs 22 ±58, p = .06) and time from non‐contrast CT to groin puncture (41 ±61 vs 61 ±65, p = .01) were shorter in the intervention cohort compared to control cohort. Length of stay and discharge mRS score were similar between the two cohorts. Conclusions Automated neuroimaging triage platform has the potential to improve workflow by decreasing time from non‐contrast CT to EVT decision and groin puncture. Further studies are required to study impact on patient outcomes.

Abstract TP42: Door To Thrombolysis Administration Times Before And After Tenecteplase Implementation Across Different Hospital Types

Background: The switch from alteplase to tenecteplase as a thrombolytic in acute ischemic stroke has been reported to be associated with faster door-to-needle (DTN) times. We aimed to study the effect of the early transitional experience after tenecteplase switch on DTN across different hospital types. Methods: We retrospectively analyzed prospectively collected data of patients that underwent thrombolysis at 7 free-standing emergency departments (FSEDs), 8 primary stroke centers (PSC), 3 thrombectomy-capable stroke centers (TSC), and a comprehensive stroke center (CSC) in a large healthcare system. The distributions of DTN time before (January 2021-January 2022) and after (January 2022-June 2022) tenecteplase implementation were compared. The Mann-Whitney test was used to compare door-to-needle time differences between alteplase and tenecteplase treatment groups. Results: Alteplase was given to 318 patients with a median DTN of 40 minutes (interquartile range [IQR]: 27;57) and 154 received tenecteplase with a median DTN of 46 minutes (IQR: 33;63). Patients in the two groups had similar demographic characteristics, NIH Stroke Scale scores, and patient distribution across hospital types. Among tenecteplase-treated patients, 68 (44%) were from FSEDs and PSCs, 67 (44%) were from TSCs, and 19 (12%) were from CSCs. The median DTN time at FSEDs and PSCs increased from 39 (IQR: 27;55) to 56 minutes (IQR: 41;72) after tenecteplase implementation (P&lt;0.0001). At the TSCs the median DTN was 40 minutes (IQR: 29;55) and did not change after the switch to tenecteplase (P=0.31). The median DTN at CSC in the alteplase group was 41 minutes (IQR: 26;72) and 33 minutes (IQR:20;45) in the tenecteplase group (P=0.06). Conclusion: For the first 6 months of tenecteplase implementation the DTN time increased at FSEDs and PSCs but remained unchanged in higher volume centers.

Abstract WP41: Should They Stay Or Should They Go? The Impact Of AI-based Care Coordination On Stroke Patient Transfers Across A Hospital Network

Introduction: A key decision facing non-thrombectomy capable hospitals is whether to transfer a suspected large vessel occlusion (LVO) patient to a thrombectomy-capable stroke center (TSC). We report our experience with a commercially available AI-based care coordination platform (Viz.ai) designed to detect and alert LVOs on imaging (CTA) and improve communication among spoke and hub providers. Methods: All patients presenting across our community hospital network (consisting of two primary stroke centers, one stroke-ready hospital, and two freestanding emergency departments) with the diagnosis of acute stroke were included. We investigated the effect of the Viz.ai software platform on the number of stroke patients transferred out of our health system to the TSC and CTA utilization by comparing transfer patterns in a cohort of patients before (pre-Viz, 12/2018 - 10/2020) and after (post-Viz, 10/2020 - 08/2022) implementation. Results: A total of 1778 pre-Viz and 1779 post-Viz patients were compared. The post-Viz transfers significantly decreased by 33% (158 post-Viz vs 236 pre-Viz, p&lt;0.0001) and the post-Viz patients receiving a CTA within our system increased by 64% (1167 post-Viz vs 710 pre-Viz, p&lt;0.0001). The proportion of patients receiving a thrombolytic (tPA or TNK) who were cared for at the spokes was significantly higher post-Viz (74% vs 63%, p=0.02). The baseline clinical characteristics and study outcomes are summarized in the Table. Conclusions: In a consecutive cohort of stroke patients across a system of community hospitals that are not thrombectomy-capable, the implementation of the Viz.ai software platform was associated with reduced transfers to the thrombectomy center and an increased use of in-house CTA for LVO screening. There was an increase in the proportion of patients treated with intravenous thrombolysis who did not undergo transfer and received care locally suggesting improved identification of patients who benefit from transfer.

Nationally Certified Stroke Centers Outperform Self-Attested Stroke Centers in the Florida Stroke Registry.

The Florida Stroke Act, signed into law in 2004, set criteria for Comprehensive Stroke Centers (CSC). For a set time period, Florida hospitals were permitted to either receive national certification (NC) or could self-attest (SA) as fulfilling CSC criteria. The aim of this project was to evaluate the quality of ischemic stroke care in NC versus SA stroke centers in Florida, using well-known, guideline-driven ischemic stroke outcome metrics. A total of 37 CSCs (74% of Florida CSCs) in the Florida Stroke Registry from January 2013 through December 2018 were analyzed, including 19 SA CSCs and 18 NC (13 CSCs and 5 Thrombectomy-Capable Stroke Center). Hospital- and patient-level characteristics and stroke metrics were evaluated, adjusting for demographics, medical comorbidities, and stroke severity. A total of 78 424 acute ischemic stroke cases, 36 089 from SA CSCs and 42 335 from NC CSC/Thrombectomy-Capable Stroke Centers were analyzed. NC centers had older patients (73 [61-83] versus 71 [60-81]; P<0.001) with more severe strokes (median National Institutes of Health Stroke Scale score of 5 versus 4; P<0.001). NC had higher intravenous tissue-type plasminogen activator utilization (15% versus 13%; P<0.001), endovascular treatment (10% versus 7%; P<0.001) and faster median door-to-computed tomography (23 minutes [11-73] versus 31 [12-78]; P<0.001), door-to-needle (37 minutes [26-50] versus 45 [34-58]; P<0.001) and door-to-puncture times (77 minutes [50-113] versus 93 [62-140]; P<0.001). In adjusted analysis, patients arriving to NC hospitals by 3 hours were more likely to get intravenous tissue-type plasminogen activator in the 3- to 4.5-hour window (adjusted odds ratio, 1.87 [95% CI, 1.30-2.68]; P=0.001) and more likely to be treated with intravenous tissue-type plasminogen activator within 45 minutes (adjusted odds ratio, 1.61 [95% CI, 1.04-2.50]; P=0.04) compared with SA CSCs. Among Florida-Stroke Registry CSCs, acute ischemic stroke performance and treatment measures at NC centers are superior to SA CSCs. These findings have implications for stroke systems of care in Florida and support legislation updates requiring NC and removal of SA claims.

151 The Impact of Minimum Volume Thresholds on Geographic Access to Stroke Thrombectomy

OBJECTIVES/GOALS: At least 15 stroke thrombectomies per proceduralist per year are required for Thrombectomy-Capable and Comprehensive Stroke Centers. We sought to estimate the potential impact of these minimum volume thresholds on geographic access to stroke thrombectomy (ST). METHODS/STUDY POPULATION: Using the Florida State Inpatient Database, we will identify patients discharged with acute ischemic stroke from 2015-2019 and all non-federal facilities that performed ≥1 ST procedure per year. We will then calculate the proportion of stroke patients who live within 20, 65, 115, 165 and 200 miles (correlating with estimated ground transport times of 1, 2, 3, 4 and 5 hours, respectively) of centers that perform ST using ArcGIS software and evaluate the impact of varying the threshold ST volume required by each facility on this proportion. We will then perform multiple two proportion z-tests to compare proportions of patients within driving distance over time. RESULTS/ANTICIPATED RESULTS: We hypothesize that over time, and particularly after the pivotal trials of ST were published in 2015, that the number of facilities that perform ST have increased over time, which would increase the geographic access to ST. We also hypothesize that since the Joint Commission set the minimum procedural volume for proceduralists at Thrombectomy-Capable and Comprehensive Stroke Center to 15 per year, this would work to increase regionalization and could work to decrease geographic access to ST. However, we hope to elucidate the net impact of the interplay between these two opposing factors on regionalization of care over time which is currently unclear. DISCUSSION/SIGNIFICANCE: Current ST volume thresholds have focused on technical proficiency but may impact regionalization of care and geographic access to ST. Since access to ST is time-sensitive, a data-driven approach and better coordination on a regional level may be necessary to ensure timely access to ST.

283 The Impact of Minimum Volume Thresholds on Geographic Access to Stroke Thrombectomy

OBJECTIVES/GOALS: At least 15 stroke thrombectomies per proceduralist per year are required for Thrombectomy-Capable and Comprehensive Stroke Centers. We sought to estimate the potential impact of these minimum volume thresholds on geographic access to stroke thrombectomy (ST). METHODS/STUDY POPULATION: Using the Florida State Inpatient Database, we will identify patients discharged with acute ischemic stroke from 2015-2019 and all non-federal facilities that performed ?1 ST procedure per year. We will then calculate the proportion of stroke patients who live within 20, 65, 115, 165 and 200 miles (correlating with estimated ground transport times of 1, 2, 3, 4 and 5 hours, respectively) of centers that perform ST using ArcGIS software and evaluate the impact of varying the threshold ST volume required by each facility on this proportion. We will then perform multiple two proportion z-tests to compare proportions of patients within driving distance over time. RESULTS/ANTICIPATED RESULTS: We hypothesize that over time, and particularly after the pivotal trials of ST were published in 2015, that the number of facilities that perform ST have increased over time, which would increase the geographic access to ST. We also hypothesize that since the Joint Commission set the minimum procedural volume for proceduralists at Thrombectomy-Capable and Comprehensive Stroke Center to 15 per year, this would work to increase regionalization and could work to decrease geographic access to ST. However, we hope to elucidate the net impact of the interplay between these two opposing factors on regionalization of care over time which is currently unclear. DISCUSSION/SIGNIFICANCE: Current ST volume thresholds have focused on technical proficiency but may impact regionalization of care and geographic access to ST. Since access to ST is time-sensitive, a data-driven approach and better coordination on a regional level may be necessary to ensure timely access to ST.

460 Access to Thrombectomy Capable Stroke Centers in the US: Current Geographic Patterns and Economic Disparities

INTRODUCTION: In the last five years, mechanical thrombectomy has revolutionized the standard of care for patients suffering from acute stroke. The mechanical thrombectomy procedures for removal of clot from large vessel of the brain has been shown to be cost effective compared to the traditional medical therapy. Given the fact that clinical outcomes are strongly dependent on time to recanalization, it is important to examine the socioeconomic disparity of geographic living distance from thrombectomy capable stroke centers (TCC) as related to patient outcomes. METHODS: The data on the US population and geographic location of thrombectomy capable stroke centers was obtained from the US Census Bureau and the websites of accrediting agencies and state governments. Using previously validated methods we estimated the population with 1 hour access to TCC. We additionally acquired median household income data for each state in the US. The proportion of population with 1 hour access to TCC was compared between low, middle and high median household states. RESULTS: There was a total of 316 TCCs in the analysis, and approximately 65% of all US residents have within one-hour access to a specialized stroke center by way of air or ground. The states with &gt;50% of the population having less than 1-hour access to thrombectomy centers, had the average median income was nearly $10,000 more when compared to states with &lt;50% of the population with 1-hour access to TCC. In high-income states, 69.0% of the population had one-hour access to TCCs. In the middle-income states, 49.5 % of the population had one-hour access to TCCs, while only 21.4 % states one-hour access to TCCs, p-value = 0.01. A positive and significant relationship between economic status and percentage population with one-hour access was observed (r = 0. 44, p-value = 0.01). CONCLUSION: One-hour access to thrombectomy capable stroke centers is available to 65% of the US residents. A positive and significant relationship between economic status and percentage population with one-hour access was observed.

Non-ischemic cerebral enhancing lesions after thrombectomy: a multicentric retrospective French national registry.

To report the occurrence of non-ischemic cerebral enhancing (NICE) lesions following mechanical thrombectomy (MT) through the retrospective French nationwide registry of NICE lesions. All thrombectomy capable stroke centers (TSC) in France were invited to fill out a questionnaire disseminated through a trainee-led research network (JENI-RC: Jeunes en Neuroradiologie Interventionnelle-Research Collaborative). NICE lesions were defined according to previous literature as delayed onset punctate, nodular, or annular foci enhancements with peri-lesion edema and vascular distribution in the territory of the MT with no other confounding disease. All 43 TSC French centers responded. Three patients were reported by 3 different centers over a total of 34,824 MT (2015-2020). Patient no. 1 developed symptomatic NICE lesions 8weeks after MT with combination of aspiration and stentriever for a right middle cerebral artery occlusion. Patient no. 2 developed asymptomatic NICE lesions 5weeks after MT with direct thromboaspiration for a right middle cerebral artery occlusion. Patient no. 3 developed symptomatic NICE lesions 6weeks after MT with direct thromboaspiration, and combination of aspiration and stentriever for a basilar artery occlusion. This study provides evidence that NICE lesions following MT are a possible rare complication with a similar presentation as previously described following endovascular aneurysm treatment. Both radiologists and neurologists should be aware of this adverse event and make use of MRI contrast agents in case of unexplained symptoms/images during follow-up after MT.