Mobile Interventional Stroke Teams Improve Outcomes in the Early Time Window for Large Vessel Occlusion Stroke.

BACKGROUND AND PURPOSE: Endovascular thrombectomy for large vessel occlusion stroke is a time-sensitive intervention. The use of a Mobile Interventional Stroke Team (MIST) traveling to Thrombectomy Capable Stroke Centers to perform endovascular thrombectomy has been shown to be significantly faster with improved discharge outcomes, as compared with the drip-and-ship (DS) model. The effect of the MIST model stratified by time of presentation has yet to be studied. We hypothesize that patients who present in the early window (last known well of ≤6 hours) will have better clinical outcomes in the MIST model. METHODS: The NYC MIST Trial and a prospectively collected stroke database were assessed for patients undergoing endovascular thrombectomy from January 2017 to February 2020. Patients presenting in early and late time windows were analyzed separately. The primary end point was the proportion with a good outcome (modified Rankin Scale score of 0-2) at 90 days. Secondary end points included discharge National Institutes of Health Stroke Scale and modified Rankin Scale. RESULTS: Among 561 cases, 226 patients fit inclusion criteria and were categorized into MIST and DS cohorts. Exclusion criteria included a baseline modified Rankin Scale score of >2, inpatient status, or fluctuating exams. In the early window, 54% (40/74) had a good 90-day outcome in the MIST model, as compared with 28% (24/86) in the DS model (P<0.01). In the late window, outcomes were similar (35% versus 41%; P=0.77). The median National Institutes of Health Stroke Scale at discharge was 5.0 and 12.0 in the early window (P<0.01) and 5.0 and 11.0 in the late window (P=0.11) in the MIST and DS models, respectively. The early window discharge modified Rankin Scale was significantly better in the MIST model (P<0.01) and similar in the late window (P=0.41). CONCLUSIONS: The MIST model in the early time window results in better 90-day outcomes compared with the DS model. This may be due to the MIST capturing high-risk fast progressors at an earlier time point. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03048292.

Repeated Mechanical Endovascular Thrombectomy for Recurrent Large Vessel Occlusion: A Multicenter Experience.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MT) is now the standard of care for large vessel occlusion (LVO) stroke. However, little is known about the frequency and outcomes of repeat MT (rMT) for patients with recurrent LVO. METHODS: This is a retrospective multicenter cohort of patients who underwent rMT at 6 tertiary institutions in the United States between March 2016 and March 2020. Procedural, imaging, and outcome data were evaluated. Outcome at discharge was evaluated using the modified Rankin Scale. RESULTS: Of 3059 patients treated with MT during the study period, 56 (1.8%) underwent at least 1 rMT. Fifty-four (96%) patients were analyzed; median age was 64 years. The median time interval between index MT and rMT was 2 days; 35 of 54 patients (65%) experienced recurrent LVO during the index hospitalization. The mechanism of stroke was cardioembolism in 30 patients (56%), intracranial atherosclerosis in 4 patients (7%), extracranial atherosclerosis in 2 patients (4%), and other causes in 18 patients (33%). A final TICI recanalization score of 2b or 3 was achieved in all 54 patients during index MT (100%) and in 51 of 54 patients (94%) during rMT. Thirty-two of 54 patients (59%) experienced recurrent LVO of a previously treated artery, mostly the pretreated left MCA (23 patients, 73%). Fifty of the 54 patients (93%) had a documented discharge modified Rankin Scale after rMT: 15 (30%) had minimal or no disability (modified Rankin Scale score ≤2), 25 (50%) had moderate to severe disability (modified Rankin Scale score 3-5), and 10 (20%) died. CONCLUSIONS: Almost 2% of patients treated with MT experience recurrent LVO, usually of a previously treated artery during the same hospitalization. Repeat MT seems to be safe and effective for attaining vessel recanalization, and good outcome can be expected in 30% of patients.

Real-World Experience with Artificial Intelligence-Based Triage in Transferred Large Vessel Occlusion Stroke Patients.

BACKGROUND AND PURPOSE: Randomized controlled trials have demonstrated the importance of time to endovascular therapy (EVT) in clinical outcomes in large vessel occlusion (LVO) acute ischemic stroke. Delays to treatment are particularly prevalent when patients require a transfer from hospitals without EVT capability onsite. A computer-aided triage system, Viz LVO, has the potential to streamline workflows. This platform includes an image viewer, a communication system, and an artificial intelligence (AI) algorithm that automatically identifies suspected LVO strokes on CTA imaging and rapidly triggers alerts. We hypothesize that the Viz application will decrease time-to-treatment, leading to improved clinical outcomes. METHODS: A retrospective analysis of a prospectively maintained database was assessed for patients who presented to a stroke center currently utilizing Viz LVO and underwent EVT following transfer for LVO stroke between July 2018 and March 2020. Time intervals and clinical outcomes were compared for 55 patients divided into pre- and post-Viz cohorts. RESULTS: The median initial door-to-neuroendovascular team (NT) notification time interval was significantly faster (25.0 min [IQR = 12.0] vs. 40.0 min [IQR = 61.0]; p = 0.01) with less variation (p < 0.05) following Viz LVO implementation. The median initial door-to-skin puncture time interval was 25 min shorter in the post-Viz cohort, although this was not statistically significant (p = 0.15). CONCLUSIONS: Preliminary results have shown that Viz LVO implementation is associated with earlier, more consistent NT notification times. This application can serve as an early warning system and a failsafe to ensure that no LVO is left behind.

Mobile Interventional Stroke Team Model Improves Early Outcomes in Large Vessel Occlusion Stroke: The NYC MIST Trial.

BACKGROUND AND PURPOSE: Triage of patients with emergent large vessel occlusion stroke to primary stroke centers followed by transfer to comprehensive stroke centers leads to increased time to endovascular therapy. A Mobile Interventional Stroke Team (MIST) provides an alternative model by transferring a MIST to a Thrombectomy Capable Stroke Center (TSC) to perform endovascular therapy. Our aim is to determine whether the MIST model is more time-efficient and leads to improved clinical outcomes compared with standard drip-and-ship (DS) and mothership models. METHODS: This is a prospective observational cohort study with 3-month follow-up between June 2016 and December 2018 at a multicenter health system, consisting of one comprehensive stroke center, 4 TSCs, and several primary stroke centers. A total of 228 of 373 patients received endovascular therapy via 1 of 4 models: mothership with patient presentation to a comprehensive stroke center, DS with patient transfer from primary stroke center or TSC to comprehensive stroke center, MIST with patient presentation to TSC and MIST transfer, or a combination of DS with patient transfer from primary stroke center to TSC and MIST. The prespecified primary end point was initial door-to-recanalization time and secondary end points measured additional time intervals and clinical outcomes at discharge and 3 months. RESULTS: MIST had a faster mean initial door-to-recanalization time than DS by 83 minutes (P<0.01). MIST and mothership had similar median door-to-recanalization times of 192 minutes and 179 minutes, respectively (P=0.83). A greater proportion had a complete recovery (National Institutes of Health Stroke Scale of 0 or 1) at discharge in MIST compared with DS (37.9% versus 16.7%; P<0.01). MIST had 52.8% of patients with modified Rankin Scale of ≤2 at 3 months compared with 38.9% in DS (P=0.10). CONCLUSIONS: MIST led to significantly faster initial door-to-recanalization times compared with DS, which was comparable to mothership. This decrease in time has translated into improved short-term outcomes and a trend towards improved long-term outcomes. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03048292.

Major Causes for Not Performing Endovascular Therapy Following Inter-Hospital Transfer in a Complex Urban Setting.

INTRODUCTION: Endovascular therapy (EVT) has emerged as the standard of care for emergent large vessel occlusion (ELVO) acute ischemic stroke. An increasing number of patients with suspected ELVO are being transferred to stroke centers with interventional capacity. Not all such inter-hospital transfers result in EVT. AIM: To identify the major causes for not performing EVT following transfer. METHODS: An analysis of 222 consecutive patients with suspected ELVO transferred for potential EVT between January 2015 and -December 2017 within a New York City health system was performed. About 36% (80/222) were deemed EVT ineligible and compared to an EVT cohort. RESULTS: Major causes for not performing EVT were established infarct (34%), no or recanalized ELVO (31%), and mild or clinically improved symptoms (21%). In the established infarct subgroup, 28% (7/27) arrived at a stroke center with interventional capacity within 5 h of last known well, compared to 61% (83/142) in the EVT cohort (p = 0.003). In the no or recanalized ELVO subgroup, 40% (10/25) received computed tomographic angiography at the primary stroke center (PSC), compared to 73% (104/142) in the EVT cohort (p = 0.001). Among patients treated with intravenous thrombolysis, 6% (6/104) improved from a NIHSS of ≥6 to <6 following transfer. CONCLUSIONS: Established infarct, no or recanalized ELVO, and mild or clinically improved symptoms were the major causes for not performing EVT for patients transferred for ELVO management. These may be addressed by decreasing stroke onset to treatment times and timely ELVO detection at the PSC and/or pre-hospital triage.

Mobile Interventional Stroke Teams Lead to Faster Treatment Times for Thrombectomy in Large Vessel Occlusion.

BACKGROUND AND PURPOSE: Endovascular recanalization treatment for acute ischemic stroke is a complex, time-sensitive intervention. Trip-and-treat is an interhospital service delivery model that has not previously been evaluated in the literature and consists of a shared mobile interventional stroke team that travels to primary stroke centers to provide on-site interventional capability. We compared treatment times between the trip-and-treat model and the traditional drip-and-ship model. METHODS: We performed a retrospective analysis on 86 consecutive eligible patients with acute ischemic stroke secondary to large vessel occlusion who received endovascular treatment at 4 hospitals in Manhattan. Patients were divided into 2 cohorts: trip-and-treat (n=39) and drip-and-ship (n=47). The primary outcome was initial door-to-puncture time, defined as the time between arrival at any hospital and arterial puncture. We also recorded and analyzed the times of last known well, IV-tPA (intravenous tissue-type plasminogen activator) administration, transfer, and reperfusion. RESULTS: Mean initial door-to-puncture time was 143 minutes for trip-and-treat and 222 minutes for drip-and-ship (P<0.0001). Although there was a trend in longer puncture-to-recanalization times for trip-and-treat (P=0.0887), initial door-to-recanalization was nonetheless 79 minutes faster for trip-and-treat (P<0.0001). There was a trend in improved admission-to-discharge change in National Institutes of Health Stroke Scale for trip-and-treat compared with drip-and-ship (P=0.0704). CONCLUSIONS: Compared with drip-and-ship, the trip-and-treat model demonstrated shorter treatment times for endovascular therapy in our series. The trip-and-treat model offers a valid alternative to current interhospital stroke transfers in urban environments.

Transferring neurointerventionalists saves time compared with interhospital transfer of stroke patients for endovascular thrombectomy: a collaborative pooled analysis of 1001 patients (EVEREST).

BACKGROUND: Interhospital transfer of stroke patients (drip and ship concept) is associated with longer treatment times compared with primary admission to a comprehensive stroke center (mothership concept). In recent years, studies on a novel concept of performing endovascular thrombectomy (EVT) at external hospitals (EXT) by transferring neurointerventionalists, instead of patients, have been published. This collaborative study aimed at answering the question of whether EXT saves time in the workflow of acute stroke treatment across various geographical regions. METHODS: This was a patient level pooled analysis of one prospective observational study and four retrospective cohort studies, the EVEREST collaboration (EndoVascular thrombEctomy at Referring and External STroke centers). Time from initial stroke imaging to EVT (vascular puncture) was compared in mothership, drip and ship, and EXT concepts. RESULTS: In total, 1001 stroke patients from various geographical regions who underwent EVT due to large vessel occlusion were included. These were divided into mothership (n=162, 16.2%), drip and ship (n=458, 45.8%), and EXT (n=381, 38.1%) cohorts. The median time periods from onset to EVT (195 min vs 320 min, p<0.001) and from imaging to EVT (97 min vs 184 min, p<0.001) in EXT were significantly shorter than for drip and ship thrombectomy concept. CONCLUSIONS: This pooled analysis of the EVEREST collaboration adds evidence that performing EVT at external hospitals can save time compared with drip and ship across various geographical regions. We encourage conducting randomized controlled trials comparing both triage concepts.

AI software detection of large vessel occlusion stroke on CT angiography: a real-world prospective diagnostic test accuracy study.

BACKGROUND: Artificial intelligence (AI) software is increasingly applied in stroke diagnostics. However, the actual performance of AI tools for identifying large vessel occlusion (LVO) stroke in real time in a real-world setting has not been fully studied. OBJECTIVE: To determine the accuracy of AI software in a real-world, three-tiered multihospital stroke network. METHODS: All consecutive head and neck CT angiography (CTA) scans performed during stroke codes and run through an AI software engine (Viz LVO) between May 2019 and October 2020 were prospectively collected. CTA readings by radiologists served as the clinical reference standard test and Viz LVO output served as the index test. Accuracy metrics were calculated. RESULTS: Of a total of 1822 CTAs performed, 190 occlusions were identified; 142 of which were internal carotid artery terminus (ICA-T), middle cerebral artery M1, or M2 locations. Accuracy metrics were analyzed for two different groups: ICA-T and M1 ±M2. For the ICA-T/M1 versus the ICA-T/M1/M2 group, sensitivity was 93.8% vs 74.6%, specificity was 91.1% vs 91.1%, negative predictive value was 99.7% vs 97.6%, accuracy was 91.2% vs 89.8%, and area under the curve was 0.95 vs 0.86, respectively. Detection rates for ICA-T, M1, and M2 occlusions were 100%, 93%, and 49%, respectively. As expected, the algorithm offered better detection rates for proximal occlusions than for mid/distal M2 occlusions (58% vs 28%, p=0.03). CONCLUSIONS: These accuracy metrics support Viz LVO as a useful adjunct tool in stroke diagnostics. Fast and accurate diagnosis with high negative predictive value mitigates missing potentially salvageable patients.

Estimating Long-Term Health Utility Scores and Expenditures for Cardiovascular Disease From the Medical Expenditure Panel Survey.

BACKGROUND: Long-term health utility scores and costs used in cost-effectiveness analyses of cardiovascular disease prevention and management can be inconsistent, outdated, or invalid for the diverse population of the United States. Our aim was to develop a user friendly, standardized, publicly available code and catalog to derive more valid long-term values for health utility and expenditures following cardiovascular disease events. METHODS: Individual-level Short Form-12 version 2 health-related quality of life and expenditure data were obtained from the pooled 2011 to 2016 Medical Expenditure Panel Surveys. We developed code using the R programming language to estimate preference-weighted Short Form-6D utility scores from the Short Form-12 for quality-adjusted life year calculations and predict annual health care expenditures. Result predictors included cardiovascular disease diagnosis (myocardial infarction, ischemic stroke, heart failure, cardiac dysrhythmias, angina pectoris, and peripheral artery disease), sociodemographic factors, and comorbidity variables. RESULTS: The cardiovascular disease diagnoses with the lowest utility scores were heart failure (0.635 [95% CI, 0.615-0.655]), angina pectoris (0.649 [95% CI, 0.630-0.667]), and ischemic stroke (0.649 [95% CI, 0.635-0.663]). The highest annual expenditures were for heart failure ($20 764 [95% CI, $17 500-$24 027]), angina pectoris ($18 428 [95% CI, $16 102-$20 754]), and ischemic stroke ($16 925 [95% CI, $15 672-$20 616]). CONCLUSIONS: The developed code and catalog may improve the quality and comparability of cost-effectiveness analyses by providing standardized methods for extracting long-term health utility scores and expenditures from Medical Expenditure Panel Survey data, which are more current and representative of the US population than previous sources.

Estimated Health Care Utilization and Expenditures in Individuals With Heart Failure From the Medical Expenditure Panel Survey.

BACKGROUND: Heart failure (HF) constitutes a growing burden for public health and the US health care system. While the prevalence of HF is increasing, differences in health care utilization and expenditures within various sociodemographic groups remain poorly defined. METHODS: We used the Medical Expenditure Panel Survey to assess annual health care utilization and expenditures from 2012 to 2017. Health care utilization was based on the annual frequency of various health care encounters. Annual total and out-of-pocket expenditures were evaluated for hospital inpatient stays, emergency room visits, outpatient visits, office-based medical provider visits, prescribed medicines, dental visits, home health aid visits, and other medical expenses. We performed univariable and multivariable regression analysis based on patient characteristics including sociodemographic and comorbidity variables. RESULTS: Our results showed that total health care expenditures among patients with HF were $21 177 (95% CI, $18 819-$24 736) per year as compared with $5652 (95% CI, $5469-$5837) in those without HF (P<0.001). Total expenditures within the population with HF were primarily being driven by expenditures associated with inpatient hospitalizations. Increasing number of comorbid conditions was associated with significant increases in total health care expenditures. Older age, female sex, earlier study years, number of comorbidities, higher level of education, and increasing family income brackets independently raised out-of-pocket expenditures. CONCLUSIONS: Our findings of increased health care utilization and expenditures based on sex, age, increasing number of comorbidities, wealthier income status, and increased education attainment level may be used for efforts aimed at better distributing health care resources to improve health outcomes in HF.

Payer Type and Emergency Department Visit Prices.

This cross-sectional study assesses list prices, cash prices, and negotiated rates for emergency department services.

Aspiration thrombectomy with off-label distal access catheters in the distal intracranial vasculature.

BACKGROUND: As neurointerventionalists aim to treat occlusions in the ever more distal vasculature, off-label catheters (OLCs) have been adapted for aspiration thrombectomy. This may not be without its attendant risks. Recently issued, a letter from the FDA cautioned providers against using OLCs as substitutes for FDA-cleared aspiration thrombectomy catheters, especially in the distal vasculature. In light of this, we evaluated the efficacy and safety of OLCs used for aspiration thrombectomy in the distal vasculature at our institution. METHODS: We retrospectively queried all patients who underwent thrombectomy at our institution between January 1, 2016 and March 1, 2017. Patients were screened for: (1) occlusion location in the distal vasculature (M2 or more distal) and (2) direct thrombus aspiration attempt with an OLC. Demographic, clinical, and procedural data were recorded. RESULTS: Eight patients were included for analysis (Table 1). The median admission NIHSS was 17 (IQR 13-23.3). Occlusion locations included left M2 (6/8), right M2 (1/8), and left M3 (1/8). The OLCs employed included the Stryker Catalyst 6 (5/8), Penumbra Velocity (2/8), and the MicroVention Sofia Plus (1/8). Direct thrombus aspiration was successful in 50% (4/8) of cases, though final TICI 2b-3 was achieved in all patients. There were no instances of symptomatic intracranial hemorrhage. Median NIHSS at discharge was 5 (IQR 0.8, 15). CONCLUSIONS: Aspiration thrombectomy with OLCs may be safe and effective in the distal vasculature. In light of the recent FDA warning regarding their use, further evaluation of OLCs in this capacity is warranted.