Prehospital stroke scales and large vessel occlusion: A systematic review

Diagnostic accuracy of 3-item stroke scale for detection of cerebral large vessel occlusion: A systematic review and meta-analysis

BACKGROUND

Prompt identification of large vessel occlusion (LVO) in acute ischemic stroke (AIS) is crucial for expedited endovascular therapy (EVT) and improved patient outcomes. Prehospital stroke scales, such as the 3-Item Stroke Scale (3I-SS), could be beneficial in detecting LVO in suspected patients. This meta-analysis evaluates the diagnostic accuracy of 3I-SS for LVO detection in AIS.

METHODS

A systematic search was conducted in Medline, Embase, Scopus, and Web of Science databases until February 2024 with no time and language restrictions. Prehospital and in-hospital studies reporting diagnostic accuracy were included. Review articles, studies without reported 3I-SS cut-offs, and studies lacking the required data were excluded. Pooled effect sizes, including area under the curve (AUC), sensitivity, specificity, diagnostic odds ratio (DOR), positive and negative likelihood ratios (PLR and NLR) with 95% confidence intervals (CI) were calculated.

RESULTS

Twenty-two studies were included in the present meta-analysis. A 3I-SS score of 2 or higher demonstrated sensitivity of 76% (95% CI: 52%-90%) and specificity of 74% (95% CI: 57%-86%) as the optimal cut-off, with an AUC of 0.81 (95% CI: 0.78-0.84). DOR, PLR, and NLR, were 9 (95% CI: 5-15), 2.9 (95% CI: 2.0-4.3) and 0.32 (95% CI: 0.17-0.61), respectively. Sensitivity analysis confirmed the analyses' robustness in suspected to stroke patients, anterior circulation LVO, assessment by paramedics, and pre-hospital settings. Meta-regression analyses pinpointed LVO definition (anterior circulation, posterior circulation) and patient setting (suspected stroke, confirmed stroke) as potential sources of heterogeneity.

CONCLUSION

3I-SS demonstrates good diagnostic accuracy in identifying LVO stroke and may be valuable in the prompt identification of patients for direct transfer to comprehensive stroke centers.

Role of Stroke Scales and Scores in Cerebrovascular Disease

This article provides a comprehensive review of widely utilized stroke scales in both routine clinical settings and research. These scales are crucial for planning treatment, predicting outcomes, and helping stroke patients recover. They also play a pivotal role in planning, executing, and comprehending stroke clinical trials. Each scale presents distinct advantages and limitations, and the authors explore these aspects within the article. The authors' intention is to provide the reader with practical insights for a clear understanding of these scales, and their effective use in their clinical practice.

Remote neurological evaluation reliably identifies patients eligible to endovascular therapy while non-eligible to intravenous thrombolysis

INTRODUCTION/BACKGROUND

Early identification of suspected stroke patients who might be eligible for a reperfusion strategy is a daily challenge in the management of patient referrals. The aim of this study was to evaluate the performance of a remote medical assessment in identifying patients eligible for endovascular therapy (EVT) while not eligible for intravenous thrombolysis (IVT), compared with a decision based on bedside clinico-radiological data.

METHODS

Patients admitted to the emergency department for acute neurological symptoms lasting for less than 24h were prospectively included. Assessment of the clinical severity and medical history was performed simultaneously by two vascular neurologists (VNs), one remotely using a mobile telemedicine solution (NOMADEEC), the other at the bedside. RACE score was calculated from the NIHSS score. At the end of the evaluation, both VNs quoted their treatment convictions (IVT/EVT). Final therapeutic decision following brain and vascular imaging was recorded and compared to remote and bedside predictions. The performances of three different conditions were evaluated: complete medical evaluation (NIHSS+medical history), NIHSS score alone, and RACE score alone. Remote and bedside performances were also compared. Diagnostic accuracy parameters (sensitivity, specificity, positive and negative predictive values) of each condition were estimated, along with their two-sided 95% binomial confidence intervals.

RESULTS

Out of 215 enrolled patients, 186 had a complete evaluation, 91 (54.3%) were diagnosed with an ischemic stroke or transient ischemic attack and 46 (24.7%) had an intracranial occlusion. Considering the three conditions evaluated remotely, RACE score-based decision provided the best sensitivity 54.6% [95% CI 23.4; 83.2]/specificity 80.6% [73.9; 86.2] combination. However, the complete medical evaluation had the best specificity (88.6% [82.9; 92.9] compared to RACE scores alone (P=0.038). Remote and bedside performances did not differ (κ=0.68 [0.59; 0.77]).

DISCUSSION/CONCLUSION

This real-life study performed in the setting of emergency demonstrates that remote medical evaluations including recording of extensive medical information and NIHSS examination to address patient's eligibility to revascularization treatment is swiftly feasible and is as effective as bedside prediction to EVT and/or IVT. Remote standardized medical evaluation might improve the decision of patients' primary orientation and avoid overcrowding of comprehensive stroke centres.

Video support for prehospital stroke consultation: implications for system design and clinical implementation from prehospital simulations

BACKGROUND

Video consultations between hospital-based neurologists and Emergency Medical Services (EMS) have potential to increase precision of decisions regarding stroke patient assessment, management and transport. In this study we explored the use of real-time video streaming for neurologist-EMS consultation from the ambulance, using highly realistic full-scale prehospital simulations including role-play between on-scene EMS teams, simulated patients (actors), and neurologists specialized in stroke and reperfusion located at the remote regional stroke center.

METHODS

Video streams from three angles were used for collaborative assessment of stroke using the National Institutes of Health Stroke Scale (NIHSS) to assess symptoms affecting patient's legs, arms, language, and facial expressions. The aim of the assessment was to determine appropriate management and transport destination based on the combination of geographical location and severity of stroke symptoms. Two realistic patient scenarios were created, with severe and moderate stroke symptoms, respectively. Each scenario was simulated using a neurologist acting as stroke patient and an ambulance team performing patient assessment. Four ambulance teams with two nurses each all performed both scenarios, for a total of eight cases. All scenarios were video recorded using handheld and fixed cameras. The audio from the video consultations was transcribed. Each team participated in a semi-structured interview, and neurologists and actors were also interviewed. Interviews were audio recorded and transcribed.

RESULTS

Analysis of video-recordings and post-interviews (n = 7) show a more thorough prehospital patient assessment, but longer total on-scene time, compared to a baseline scenario not using video consultation. Both ambulance nurses and neurologists deem that video consultation has potential to provide improved precision of assessment of stroke patients. Interviews verify the system design effectiveness and suggest minor modifications.

CONCLUSIONS

The results indicate potential patient benefit based on a more effective assessment of the patient's condition, which could lead to increased precision in decisions and more patients receiving optimal care. The findings outline requirements for pilot implementation and future clinical tests.

Prehospital identification of acute ischaemic stroke with large vessel occlusion: a retrospective study from western Norway

BACKGROUND

In 2019, the emergency medical services (EMS) covering the western Norway Regional Health Authority area implemented its version of the prehospital clinical criteria G-FAST (Gaze deviation, Facial palsy, Arm weakness, Visual loss, Speech disturbance) to detect acute ischaemic stroke (AIS) with large vessel occlusion (LVO). For patients with gaze deviation and at least one other G-FAST symptom, a primary stroke centre (PSC) may be bypassed and the patient taken directly to a comprehensive stroke centre (CSC) for rapid endovascular treatment (EVT) evaluation. The study aim was to investigate the efficacy of the G-FAST criteria for LVO patient selection and direct transfer to a CSC.

METHODS

This retrospective study included patients with code-red emergency medical communication centre (EMCC) stroke suspicion ambulance dispatch between August to December 2020. Stroke suspicion was defined as having at least one G-FAST symptom at EMS arrival. We obtained patient data from dispatches from EMCCs, EMS records and local EVT registries. Clinical features, CT images, and reperfusion treatment were recorded. The test characteristics for gaze deviation plus one other G-FAST symptom in detecting LVO were determined.

RESULTS

Among 643 patients, 59 were diagnosed with LVO at hospital arrival. In this group, seven fulfilled the G-FAST criteria for direct transport to a CSC at EMS arrival on scene, resulting in a sensitivity of 12% (95% CI 5% to 23%). The specificity was 99.66% (95% CI 98.77% to 99.96%), the positive predictive value 78%, and the negative predictive value 92%. EVT was performed in 64% (38/59) of LVO cases. Median time from PSC arrival to start of EVT at a CSC was 163 min.

CONCLUSION

The use of local G-FAST prehospital criteria by EMS personnel to identify patients with AIS with LVO is not suitable for selection of patients with LVO for direct transfer to a CSC.

Time-driven activity-based costing (TDABC) of direct-to-angiography pathway for acute ischemic stroke patients with suspected large vessel occlusion

INTRODUCTION

Direct-to-angiography (DTA) is a novel care pathway for endovascular treatment (EVT) of acute ischemic stroke (AIS) that has been shown to reduce time-to-treatment and improve clinical outcomes for EVT-eligible patients. The institutional costs of adopting the DTA pathway and the many factors affecting costs have not been studied. In this study, we assess the costs and main cost drivers associated with the DTA pathway compared to the conventional CT pathway for patients presenting with AIS and suspected LVO in the anterior circulation.

METHODS

Time driven activity based costing (TDABC) model was used to compare costs of DTA and conventional pathways from the healthcare institution perspective. Process mapping was used to outline all activities and resources (personnel, equipment, materials) needed for each step in both pathways. The cost model was developed using our institutional patient database and average New York state wages for personnel costs. Total, incremental and proportional costs were calculated based on institutional and patient factors affecting the pathways.

RESULTS

DTA pathway accrued additional $82,583.61 (9%) in total costs compared to the conventional approach for all AIS patients. For EVT-ineligible patients, the DTA pathway incurred additional $82,964.37 (76%) in total costs compared to the CT pathway. For EVT eligible patients, the total and per-patient costs were greater in the CT pathway by $380.76 (0.04%) and $5.60 (0.04%) respectively.

CONCLUSION

As the DTA pathway incurred additional $82,964.37 for EVT-ineligible patients, appropriate patient selection criteria are needed to avoid transferring EVT-ineligible patients to the angiography suite.

The non-paretic-hand-to-opposite-ear test: A simple test to detect aphasia and neglect and an indicator of large anterior vessel occlusion in patients with suspected acute stroke

INTRODUCTION

Aphasia and neglect in combination with hemiparesis are reliable indicators of large anterior vessel occlusion (LAVO). Prehospital identification of these symptoms is generally considered difficult by emergency medical service (EMS) personnel. Therefore, we evaluated the simple non-paretic-hand-to-opposite-ear (NPE) test to identify aphasia and neglect with a single test. As the NPE test includes a test for arm paresis, we also evaluated the diagnostic ability of the NPE test to detect LAVO in patients with suspected stroke.

METHODS

In this prospective observational study, we performed the NPE test in 1042 patients with suspected acute stroke between May 2021 and May 2022. We analyzed the correlation between the NPE test and the aphasia/neglect items of the National Institutes of Health Stroke Scale. Additionally, the predictive values of the NPE test for LAVO detection were calculated.

RESULTS

The NPE test showed a strong, significant correlation with both aphasia and neglect. A positive NPE test result predicted LAVO with a sensitivity of 0.70, a specificity of 0.88, and an accuracy of 0.85. Logistic regression analysis showed an odds ratio of 16.14 (95% confidence interval 10.82-24.44) for predicting LAVO.

CONCLUSION

The NPE test is a simple test for the detection of both aphasia and neglect. With its predictive values for LAVO detection being comparable to the results of LAVO scores in the prehospital setting, this simple test might be a promising test for prehospital LAVO detection by EMS personnel. Further prospective prehospital validation is needed.

Identification of Anterior Large Vessel Occlusion Stroke During the Emergency Call: Protocol for a Controlled, Nonrandomized Trial

BACKGROUND

Endovascular thrombectomy (ET), combined with intravenous thrombolysis if possible, is an effective treatment option for patients with stroke who have confirmed anterior large vessel occlusion (aLVO). However, ET is mainly limited to comprehensive stroke centers (CSCs), resulting in a lack of ET capacity in remote, sparsely populated areas. Most stroke networks use the "Drip and Ship" or "Mothership" strategy, resulting in either delayed ET or intravenous thrombolysis, respectively.

OBJECTIVE

This study protocol introduces the Leitstellen-Basierte Erkennung von Schlaganfall-Patienten für eine Thrombektomie und daraufhin abgestimmte Optimierung der Rettungskette (LESTOR) strategy, developed to optimize the preclinical part of the stroke chain of survival to improve the clinical outcome of patients with suspected aLVO stroke. This involves refining the dispatch strategy for identifying patients with acute aLVO stroke using a phone-based aLVO query. This includes dispatching emergency physicians and emergency medical services (EMS) to urban emergency sites, as well as dispatching helicopter EMS to remote areas. If a highly suspected aLVO is identified after a standardized aLVO score evaluation during a structured examination at the emergency scene, prompt transport to a CSC should be prioritized.

METHODS

The LESTOR study is a controlled, nonrandomized study implementing the LESTOR strategy, with a stepped-wedge, cluster trial design in 6 districts in southwest Germany. In an interprofessional, iterative approach, an aLVO query or dispatch protocol intended for use by dispatchers, followed by a coordinated aLVO examination score for use by EMS, is being developed, evaluated, and pretested in a simulation study. After the training of all participating health care professionals with the corresponding final aLVO query, the LESTOR strategy is being implemented stepwise. Patients otherwise receive usual stroke care in both the control and intervention groups. The primary outcome is the modified Rankin Scale at 90 days in patients with stroke receiving endovascular treatment. We will use a generalized linear mixed model for data analysis. This study is accompanied by a cost-effectiveness analysis and a qualitative process evaluation.

RESULTS

This paper describes and discusses the protocol for this controlled, nonrandomized LESTOR study. Enrollment was completed in June 2023. Data analysis is ongoing and the first results are expected to be submitted for publication in 2024. The project started in April 2020 and will end in February 2024.

CONCLUSIONS

We expect that the intervention will improve the clinical outcome of patients with aLVO stroke, especially outside the catchment areas of CSCs. The results of the accompanying process evaluation and the cost-effectiveness analysis will provide further insights into the implementation process and allow for a better interpretation of the results.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00022152; https://drks.de/search/de/trial/DRKS00022152.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51683.

Real-time video analysis allows the identification of large vessel occlusion in patients with suspected stroke: feasibility trial of a "telestroke" pathway in Northwestern Switzerland

Background and aim

Loss of time is a major obstacle to efficient stroke treatment. Our telestroke path intends to optimize prehospital triage using a video link connecting ambulance personnel and a stroke physician. The objectives were as follows: (1) To identify patients suffering a stroke and (2) in particular large vessel occlusion (LVO) strokes as candidates for endovascular treatment. We have chosen the Rapid Arterial Occlusion Evaluation (RACE) scale for this purpose.

Methods

This analysis aimed to verify the feasibility of prehospital stroke identification by video assessment. In this prospective telestroke cohort study, we included 97 subjects, in which the RACE score (items: facial palsy, arm and leg motor function, head and gaze deviation, and aphasia or agnosia) was applied, and the assessment videotaped by a trained member of the Emergency Medical Services (EMS) in the field using a mobile device. Each recorded patient video was independently assessed by three experienced stroke physicians from a certified stroke center and compared to the neuroimaging gold standard. Within this feasibility study, the stroke code was not altered by the outcome of the RACE assessment, and all patients underwent the standard procedures within the emergency unit.

Results

We analyzed 97 patients (median age 78 years, 53% women), of whom 51 (52.6%) suffered an acute stroke, 12 (23.5%) of which were due to an LVO and 46 patients had symptoms mimicking a stroke. The sensitivity of stroke identification was 77.8%, and specificity was 53.6%. In regard to the identification of an LVO, sensitivity was 69.4% and specificity was 84.3%. The inter-rater agreement in the RACE-score assessment was ICC = 0.82 (intraclass-correlation coefficient).

Conclusion

These results confirm our hypothesis that the local telestroke concept is feasible. It allows correct (i) stroke and (ii) LVO identification in the majority of the cases and thus has the potential to assist in efficient prehospital triage.

Inter-Rater Agreement on Cincinnati Prehospital Stroke Scale (CPSS) and Prehospital Acute Stroke Severity Scale (PASS) Between EMS Providers, Neurology Residents and Neurology Consultants

Objective

To examine the agreement between emergency medical service (EMS) providers, neurology residents and neurology consultants, using the Cincinnati Prehospital Stroke Scale (CPSS) and the Prehospital Acute Stroke Severity Scale (PASS).

Methods

Patients with stroke, transient ischemic attack (TIA) and stroke mimic were included upon primary stroke admission or during rehabilitation. Patients were included from June 2018 to September 2019. Video recordings were made of patients being assessed with CPSS and PASS. The recordings were later presented to the healthcare professionals. To determine relative and absolute interrater reliability in terms of inter-rater agreement (IRA), we used generalisability theory. Group-level agreement was determined against a gold standard and presented as an area under the curve (AUC). The gold standard was a consensus agreement between two neurology consultants.

Results

A total of 120 patient recordings were assessed by 30 EMS providers, two neurology residents and two neurology consultants. Using the CPSS and the PASS, a total of 1,800 assessments were completed by EMS providers, 240 by neurology residents and 240 by neurology consultants. The overall relative and absolute IRA for all items combined from the CPSS and PASS score was 0.84 (95% CI 0.80; 0.87) and 0.81 (95% CI 0.77; 0.85), respectively. Using the CPSS, the agreement on a group-level resulted in AUCs of 0.83 (95% CI 0.78; 0.88) for the EMS providers and 0.86 (95% CI 0.82; 0.90) for the neurology residents when compared with the gold standard. Using the PASS, the AUC was 0.82 (95% CI 0.77; 0.87) for the EMS providers and 0.88 (95% CI 0.84; 0.93) for the neurology residents.

Conclusion

The high relative and absolute inter-rater agreement underpins a high robustness/generalisability of the two scales. A high agreement exists across individual raters and different groups of healthcare professionals supporting widespread applicability of the stroke scales.

Early identification and characterisation of stroke to support prehospital decision-making using artificial intelligence: a scoping review protocol

INTRODUCTION

Stroke is a time-critical condition and one of the leading causes of mortality and disability worldwide. To decrease mortality and improve patient outcome by improving access to optimal treatment, there is an emerging need to improve the accuracy of the methods used to identify and characterise stroke in prehospital settings and emergency departments (EDs). This might be accomplished by developing computerised decision support systems (CDSSs) that are based on artificial intelligence (AI) and potential new data sources such as vital signs, biomarkers and image and video analysis. This scoping review aims to summarise literature on existing methods for early characterisation of stroke by using AI.

METHODS AND ANALYSIS

The review will be performed with respect to the Arksey and O'Malley's model. Peer-reviewed articles about AI-based CDSSs for the characterisation of stroke or new potential data sources for stroke CDSSs, published between January 1995 and April 2023 and written in English, will be included. Studies reporting methods that depend on mobile CT scanning or with no focus on prehospital or ED care will be excluded. Screening will be done in two steps: title and abstract screening followed by full-text screening. Two reviewers will perform the screening process independently, and a third reviewer will be involved in case of disagreement. Final decision will be made based on majority vote. Results will be reported using a descriptive summary and thematic analysis.

ETHICS AND DISSEMINATION

The methodology used in the protocol is based on information publicly available and does not need ethical approval. The results from the review will be submitted for publication in a peer-reviewed journal. The findings will be shared at relevant national and international conferences and meetings in the field of digital health and neurology.

Less is more - The Finnish Prehospital Stroke Scale prospective validation

OBJECTIVES

The current bifurcation of the acute stroke care pathway requires prehospital separation of strokes caused by large vessel occlusion. The first four binary items of the Finnish Prehospital Stroke Scale (FPSS) identify stroke in general, while the fifth binary item alone identifies stroke due to large vessel occlusion. The straightforward design is both easy for paramedics and statistically beneficial. We implemented FPSS based Western Finland Stroke Triage Plan, including medical districts of a comprehensive stroke center and four primary stroke centers.

PATIENTS AND METHODS

The prospective study population was consecutive recanalization candidates transported to the comprehensive stroke center within the first six months of implementing the stroke triage plan. Cohort 1 consisted of n=302 thrombolysis- or endovascular treatment candidates transported from the comprehensive stroke center hospital district. Cohort 2 comprised ten endovascular treatment candidates transferred directly to the comprehensive stroke center from the medical districts of four primary stroke centers.

RESULTS

In Cohort 1, FPSS sensitivity for large vessel occlusion was 0.66, specificity 0.94, positive predictive value 0.70, and negative predictive value 0.93. Of the ten Cohort 2 patients, nine had large vessel occlusion, and one had an intracerebral hemorrhage.

CONCLUSIONS

FPSS is straightforward enough to be implemented in primary care services to identify candidates for endovascular treatment and thrombolysis. When used by paramedics, it predicted two-thirds of large vessel occlusions with the highest specificity and positive predictive value reported to date.

What predicts large vessel occlusion in mild stroke patients?

BACKGROUND AND PURPOSE

Mild acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) may benefit from thrombolysis or thrombectomy therapy. However, the predictors for LVO in mild AIS patients have not been extensively explored. We aimed to investigate the predictors for LVO in mild AIS patients.

METHODS

We collected the data of consecutive AIS patients with a National Institutes of Health Stroke Scale (NIHSS) score ≤ 5 from The Third China National Stroke Registry - a prospective nationwide registry of AIS or transient ischemic attack (TIA) patients in China from August 2015 to March 2018. Patients were divided into LVO and non-LVO group based on the vascular imaging during the hospitalization. Multivariable regression analyses involving clinical characteristics and NIHSS subitems was performed to detect the predictors for LVO.

RESULT

A total of 7653 mild AIS patients from The Third China National Stroke Registry were included in this study. Among them, 620 patients (8.1%) had LVO. The level of consciousness (adjusted odds ratio, 1.87; 95% confidence interval, 1.08 to 3.23), visual field (adjusted odds ratio, 2.10; 95% confidence interval, 1.43 to 3.06) and sensory (adjusted odds ratio, 0.75; 95% confidence interval, 0.60 to 0.94) were predictors for mild AIS patients with LVO.

CONCLUSIONS

Impaired LOC, visual field and sensory were independently predictors for LVO in mild stroke patients. Further studies are warranted to test these predictors in prehospital setting and in other population.

Factors Predicting Misidentification of Acute Ischemic Stroke and Large Vessel Occlusion by Paramedics

The emergence of thrombectomy for large vessel occlusions has increased the importance of accurate prehospital identification and triage of acute ischemic stroke (AIS). Despite available clinical scores, prehospital identification is suboptimal. Our objective was to improve the sensitivity of prehospital AIS identification by combining dispatch information with paramedic impression. We performed a retrospective cohort review of emergency medical services and hospital records of all patients for whom a stroke alert was activated in 1 urban, academic emergency department from January 1, 2018, to December 31, 2019. Using admission diagnosis of acute stroke as outcome, we calculated the sensitivity and specificity of dispatch and paramedic impression in identifying AIS and large vessel occlusion. We identified factors that, when included together, would improve the sensitivity of prehospital AIS identification. Two-hundred twenty-six stroke alerts were activated by emergency department physicians after transport by Indianapolis emergency medical services. Forty-four percent (99/226) were female, median age was 58 years (interquartile range, 50-67 years), and median National Institutes of Health Stroke Scale was 6 (interquartile range, 2-12). Paramedics demonstrated superior sensitivity (59% vs. 48%) but inferior specificity (56% vs. 73%) for detection of stroke as compared with dispatch. A strategy incorporating dispatch code of stroke, or paramedic impression of altered mental status or weakness in addition to stroke, would be 84% sensitive and 27% specific for identification of stroke. To optimize rapid and sensitive stroke detection, prehospital systems should consider inclusion of patients with dispatch code of stroke and provider impression of altered mental status or generalized weakness.

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

Background

The outcome of mechanical thrombectomy for large vessel occlusion (LVO) in patients with acute ischemic stroke (AIS) is time-dependent. In the current stroke workflow, the pre-hospital delay is one of the most common reasons for an increase in door-to-groin puncture time (DGPT). In the present study, we sought to compare the difference in (DGPT) before and after the implementation of the Ventura Emergent Large Vessel Occlusion Score (VES) protocol for LVO.

Methods

VES was implemented in the Ventura County of California by Emergency Medical Services (EMS). We performed a retrospective analysis to compare DGPT of patients undergoing endovascular treatment (EVT) pre- and post-VES implementation. Mean and standard deviation was reported for the continuous variable ‘time for intra-arterial (IA) treatment’ in minutes. The Mann-Whitney test was used for the comparison of the variable between the two groups. analyses were performed using SAS v9.4 (SAS Institute Inc., Cary, NC) with a significant p-value of ≤0.05.

Results

A total of 304 (males: 142 and females: 162) patients were alerted of the stroke code by the EMS. VES was positive in 139 patients. Of these, 64 (46%) were males and 75 (54%) were females. VES score of 1, 2, 3, and 4 were recorded in 57 (41%), 44 (31.6%), 31 (22.3%), and 7 (5%) patients, respectively. A total of 48 VES-positive patients underwent EVT. There were 62 patients who underwent EVT before the implementation of the VES protocol. The mean DGPT for the EVT among post-VES patients was 65 minutes, which was significantly (p=0.0009) shorter than the mean DGPT of 109 minutes among pre-VES patients.

Conclusion

VES is a simplified and effective tool for identifying LVO in the field. Implementation of VES showed significantly reduced DGPT in LVO patients.

Cortical symptoms described in emergency calls for patients with suspected large vessel occlusion: a descriptive analysis of 157 emergency calls

Background

Emergency medical dispatchers typically use the dispatch code for suspected stroke when the caller brings up one or more symptoms from the face-arm-speech triad. Paramedics and emergency department physicians are trained to suspect large vessel occlusion stroke when the stroke patient presents with hemiparesis and cortical symptoms: neglect, aphasia, and conjugate eye deviation (CED). We hypothesized that these symptoms could be evident in the emergency call.

In this study, we aimed to describe common symptoms mentioned in the emergency calls for paramedic-suspected thrombectomy candidates. Secondly, we wanted to explore how the question about CED arises in the Finnish suspected stroke dispatch protocol. Our third aim was to find out if the symptoms brought up in suspected stroke and non-stroke dispatches differed from each other.

Methods

This was a retrospective study with a descriptive analysis of emergency calls for patients with paramedic-suspected large vessel occlusion stroke. We listened to the emergency calls for 157 patients transported to Tampere University Hospital, a Finnish comprehensive stroke centre. Two researchers listened for symptoms brought up in these calls and filled out a pre-planned case report form.

Results

Speech disturbance was the most common symptom brought up in 125 (80%) calls. This was typically described as an inability to speak any words (n = 65, 52% of calls with speech disturbance). Other common symptoms were falling down (n = 63, 40%) and facial asymmetry (n = 41, 26%). Suspicion of stroke was mentioned by 44 (28%) callers. When the caller mentioned unconsciousness the emergency dispatcher tended to use a non-stroke dispatch code. The dispatchers adhered poorly to the protocol and asked about CED in only 57% of suspected stroke dispatches. We found CED in 12 emergency calls and ten of these patients were diagnosed with large vessel occlusion.

Conclusion

In cases where paramedics suspected large vessel occlusion stroke, typical stroke symptoms were described during the emergency call. Speech disturbance was typically described as inability to say anything. It is possible to further develop suspected stroke dispatch protocols to recognize thrombectomy candidates from ischemic cortical signs such as global aphasia and CED.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00706-5.

Optimizing Time Management for Drip-and-Ship Stroke Patients Qualifying for Endovascular Therapy-A Single-Network Study

BACKGROUND: We sought to identify factors for delayed drip-and-ship (DS) management in stroke patients transferred from primary hospitals to our comprehensive stroke center (CSC) for endovascular therapy (EVT). METHODS: We conducted a retrospective study of all patients transferred to our CSC for EVT between 2016 and 2020. We analyzed emergency and hospital records to assess DS process times and factors predictive of delays. We dichotomized the admission period to 2016−2017 and 2018−2020 according to the main process optimization, including the introduction of a prenotification call. RESULTS: We included 869 DS patients (median age 76 years (IQR 65−82), NIHSS 16 (IQR 11−21), 278 min (IQR 243−335) from onset to EVT); 566 were transferred in 2018−2020. Admission in 2016−2017, during on-call, longer tranfer distance, and general anesthesia were factors independently associated with delayed onset to EVT time (F(5, 352) = 14.76, p < 0.000). Other factors associated with delayed DS management were: transfer mode, primary hospital type, site of large-vessel occlusion, and intravenous thrombolysis. Total transfer time was faster for distances <50 km by ambulance and for distances >71 km by helicopter. CONCLUSION: Assessment of DS processes and times throughout the patient pathway allows identification of potentially modifiable factors for improvement of the very time-critical workflow for stroke patients.

Streamlining Acute Stroke Care by Introducing National Institutes of Health Stroke Scale in the Emergency Medical Services: A Prospective Cohort Study

National Institutes of Health Stroke Scale (NIHSS) is the most validated clinical scale for stroke recognition, severity grading, and symptom monitoring in acute care and hospital settings. Numerous modified prehospital stroke scales exist, but these scales contain less clinical information and lack compatibility with in-hospital stroke scales. In this real-life study, we aimed to investigate if NIHSS conducted by paramedics in the field is a feasible and accurate prehospital diagnostic tool.

A novel emergency medical services protocol to improve treatment time for large vessel occlusion strokes

In many systems, patients with large vessel occlusion (LVO) strokes experience delays in transport to thrombectomy-capable centers. This pilot study examined use of a novel emergency medical services (EMS) protocol to expedite transfer of patients with LVOs to a comprehensive stroke center (CSC). From October 1, 2020 to February 22, 2021, Indianapolis EMS piloted a protocol, in which paramedics, after transporting a patient with a possible stroke remained at the patient's bedside until released by the emergency department or neurology physician. In patients with possible LVO, EMS providers remained at the bedside until the clinical assessment and CT angiography (CTA) were complete. If indicated, the paramedics at bedside transferred the patient, via the same ambulance, to a nearby thrombectomy-capable CSC with which an automatic transfer agreement had been arranged. This five-month mixed methods study included case-control assessment of use of the protocol, number of transfers, safety during transport, and time saved in transfer compared to emergent transfers via conventional interfacility transfer agencies. In qualitative analysis EMS providers, and ED physicians and neurologists at both sending and receiving institutions, completed e-mail surveys on the process, and offered suggestions for process improvement. Responses were coded with an inductive content analysis approach. The protocol was used 42 times during the study period; four patients were found to have LVOs and were transferred to the CSC. There were no adverse events. Median time from decision-to-transfer to arrival at the CSC was 27.5 minutes (IQR 24.5-29.0), compared to 314.5 minutes (IQR 204.0-459.3) for acute non-stroke transfers during the same period. Major themes of provider impressions included: incomplete awareness of the protocol, smooth process, challenges when a stroke alert was activated after EMS left the hospital, greater involvement of EMS in patient care, and comments on communication and efficiency. This pilot study demonstrated the feasibility, safety, and efficiency of a novel approach to expedite endovascular therapy for patients with LVOs.

Optimization of Large Vessel Occlusion Detection in Acute Ischemic Stroke Using Machine Learning Methods

The early detection of large-vessel occlusion (LVO) strokes is increasingly important as these patients are potential candidates for endovascular therapy, the availability of which is limited. Prehospital LVO detection scales mainly contain symptom variables only; however, recent studies revealed that other types of variables could be useful as well. Our aim was to comprehensively assess the predictive ability of several clinical variables for LVO prediction and to develop an optimal combination of them using machine learning tools. We have retrospectively analysed data from a prospectively collected multi-centre stroke registry. Data on 41 variables were collected and divided into four groups (baseline vital parameters/demographic data, medical history, laboratory values, and symptoms). Following the univariate analysis, the LASSO method was used for feature selection to select an optimal combination of variables, and various machine learning methods (random forest (RF), logistic regression (LR), elastic net method (ENM), and simple neural network (SNN)) were applied to optimize the performance of the model. A total of 526 patients were included. Several neurological symptoms were more common and more severe in the group of LVO patients. Atrial fibrillation (AF) was more common, and serum white blood cell (WBC) counts were higher in the LVO group, while systolic blood pressure (SBP) was lower among LVO patients. Using the LASSO method, nine variables were selected for modelling (six symptom variables, AF, chronic heart failure, and WBC count). When applying machine learning methods and 10-fold cross validation using the selected variables, all models proved to have an AUC between 0.736 (RF) and 0.775 (LR), similar to the performance of National Institutes of Health Stroke Scale (AUC: 0.790). Our study highlights that, although certain neurological symptoms have the best ability to predict an LVO, other variables (such as AF and CHF in medical history and white blood cell counts) should also be included in multivariate models to optimize their efficiency.

Pharmacological brain cytoprotection in acute ischaemic stroke — renewed hope in the reperfusion era

For over 40 years, attempts to develop treatments that protect neurons and other brain cells against the cellular and biochemical consequences of cerebral ischaemia in acute ischaemic stroke (AIS) have been unsuccessful. However, the advent of intravenous thrombolysis and endovascular thrombectomy has taken us into a new era of treatment for AIS in which highly effective reperfusion therapy is widely available. In this context, cytoprotective treatments should be revisited as adjunctive treatment to reperfusion therapy. Renewed efforts should focus on developing new drugs that target multiple aspects of the ischaemic cascade, and previously developed drugs should be reconsidered if they produced robust cytoprotective effects in preclinical models and their safety profiles were reasonable in previous clinical trials. Several development pathways for cytoprotection as an adjunct to reperfusion can be envisioned. In this Review, we outline the targets for cytoprotective therapy and discuss considerations for future drug development, highlighting the recent ESCAPE-NA1 trial of nerinetide, which produced the most promising results to date. We review new types of clinical trial to evaluate whether cytoprotective drugs can slow infarct growth prior to reperfusion and/or ameliorate the consequences of reperfusion, such as haemorrhagic transformation. We also highlight how advanced brain imaging can help to identify patients with salvageable ischaemic tissue who are likely to benefit from cytoprotective therapy.

In this Review, Fisher and Savitz consider how the era of reperfusion therapy in ischaemic stroke provides new hope for the development of cytoprotective therapies to further improve outcomes, highlighting how promising recent findings can be built on to benefit patients.

Highly successful reperfusion therapy with intravenous thrombolysis and endovascular thrombectomy is now widely available for the treatment of acute ischaemic stroke, making cytoprotective therapy a viable additional treatment approach.

Previous attempts to develop cytoprotective therapy have been unsuccessful, but this approach should now be reconsidered as an adjunctive therapy to thrombolysis and thrombectomy.

New cytoprotective drugs should be developed to target multiple aspects of the ischaemic cascade, and previously developed drugs should be reconsidered.

Trials should be conducted to evaluate the effects of cytoprotective drugs when administered before or after reperfusion therapy or both.

Advanced brain imaging should be used to select patients who are most likely to benefit from cytoprotective treatment for enrolment in new trials.

Assessment of Clinical Scales for Detection of Large Vessel Occlusion in Ischemic Stroke Patients from the Dijon Stroke Registry

(1) Background: The limited availability of thrombectomy-capable stroke centres raises questions about pre-hospital triage of patients with suspected stroke (IS) due to large vessel occlusion (LVO). Aims: This study aimed to evaluate the diagnostic accuracy of clinical stroke severity scales available for LVO detection. (2) Methods: Patients with IS were prospectively identified among residents of Dijon, France, using a population-based registry (2013–2017). Clinical signs and arterial imaging data were collected. LVO was defined as an occlusion site affecting the terminal intracranial internal carotid artery, the M1 segment of the middle cerebral artery (MCA), or the basilar artery (restricted definition). A wide definition of LVO also included the M2 segment of the MCA. For each of the 16 evaluated scales, a receiver operator characteristic (ROC) analysis was performed, and the c-statistic representing the area under the ROC curve was evaluated to assess discrimination for predicting LVO. (3) Results: 971 patients were registered, including 123 patients (12.7%) with an LVO according to the restricted definition. The c-statistic for LVO detection ranged between 0.66 and 0.80 according to the different scales, with a sensibility varying from 70% to 98% and a specificity from 33% to 86%. According to the wide definition of LVO (174 patients, 17.9%), the c-statistic was slightly lower, ranging between 0.64 and 0.79. The sensitivity was 59% to 93%, and the specificity was 34% to 89%. (4) Conclusion: The clinical scales failed to combine a high sensitivity and a high specificity to detect LVO. Further studies are needed to determine the best strategy for pre-hospital triage of IS patients.

Validation of the Italian version of the ROSIER scale for stroke patients at triage

BACKGROUND

The ROSIER scale allows rapid evaluation of patients with suspected stroke; this paper presents the validation of an Italian version of the ROSIER scale.

METHODS

Observational study in the emergency department of a major teaching hospital. Patients aged 18 or more, admitted to the emergency department, during a period of two years were enrolled. Construct validity was investigated through exploratory factor analysis (EFA), content validity through the content validity index (CVI-I). Internal consistency, interrater reliability and test-retest stability were assessed. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

539 subjects were enrolled. The Italian ROSIER scale (ROSIER-ita) showed a sensitivity of 97.6%, a specificity of 90.1%, a positive predictive value of 97.5% and a negative predictive value of 82.7%. EFA pointed out 1 factor; the ROSIER-ita explained 59.79% of total variance. Content validity was satisfying (CVI-I = 0.97). No significant differences (p = 0.90) were found in the scores of the first 50 recorded at the time of admission and after 10 min. Interrater reliability was excellent (rho = 0.96, p = 0.0066). Cronbach's alpha was 0.74, indicating acceptable correlation between the items.

CONCLUSION

The Italian version of the ROSIER scale showed satisfactory results, comparable to the original English version, and can be applied by emergency nurses.

Direct Transfer to Angiosuite in Acute Stroke: Why, When, and How?

Time to reperfusion is one of the strongest predictors of functional outcome in acute stroke due to a large vessel occlusion (LVO). Direct transfer to angiography suite (DTAS) protocols have shown encouraging results in reducing in-hospital delays. DTAS allows bypassing of conventional imaging in the emergency room by ruling out an intracranial hemorrhage or a large established infarct with imaging performed before transfer to the thrombectomy-capable center in the angiography suite using flat-panel CT (FP-CT). The rate of patients with stroke code primarily admitted to a comprehensive stroke center with a large ischemic established lesion is <10% within 6 hours from onset and remains <20% among patients with LVO or transferred from a primary stroke center. At the same time, stroke severity is an acceptable predictor of LVO. Therefore, ideal DTAS candidates are patients admitted in the early window with severe symptoms. The main difference between protocols adopted in different centers is the inclusion of FP-CT angiography to confirm an LVO before femoral puncture. While some centers advocate for FP-CT angiography, others favor additional time saving by directly assessing the presence of LVO with an angiogram. The latter, however, leads to unnecessary arterial punctures in patients with no LVO (3%-22% depending on selection criteria). Independently of these different imaging protocols, DTAS has been shown to be effective and safe in improving in-hospital workflow, achieving a reduction of door-to-puncture time as low as 16 minutes without safety concerns. The impact of DTAS on long-term functional outcomes varies between published studies, and randomized controlled trials are warranted to examine the benefit of DTAS.

Prediction of large vessel occlusion for ischaemic stroke by using the machine learning model random forests

BACKGROUNDS

The timely identification of large vessel occlusion (LVO) in the prehospital stage is extremely important given the disease morbidity and narrow time window for intervention. The current evaluation strategies still remain challenging. The goal of this study was to develop a machine learning (ML) model to predict LVO using prehospital accessible data.

METHODS

Consecutive acute ischaemic stroke patients who underwent CT or MR angiography and received reperfusion therapy within 8 hours from symptom onset in the Computer-based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation-II dataset from January 2016 to August 2021 were included. We developed eight ML models to integrate National Institutes of Health Stroke Scale (NIHSS) items with demographics, medical history and vascular risk factors to identify LVO and validate its efficiency.

RESULTS

Finally, 15 365 patients were included in the training set and 4215 patients were included in the test set. On the test set, random forests (RF), gradient boosting machine and extreme gradient boosting presented area under the curve (AUC) of 0.831 (95% CI 0.819 to 0.843), which were higher than other models, and RF presented the highest specificity (0.827). In addition, the AUC of RF was higher than other scales, and the accuracy of the model was improved by 6.4% compared with NIHSS. We also found the top five items of identifying LVO were total NIHSS score, gaze deviation, level of consciousness (LOC), LOC commands and motor left leg.

CONCLUSIONS

Our proposed model could be a useful screening tool to predict LVO based on the prehospital accessible medical data.

TRIAL REGISTRATION NUMBER

NCT04487340.

Novel Prehospital Triage Scale for Detecting Large Vessel Occlusion and Its Cause

Background

Patients with large vessel occlusion stroke (LVOS) need to be rapidly identified and transferred to comprehensive stroke centers. However, current prehospital evaluation and strategies still remain challenging.

Methods and Results

We retrospectively reviewed our prospectively collected database of patients with acute ischemic stroke (AIS). Based on the items of National Institutes of Health Stroke Scale and medical history that had a strong association with LVOS, we designed the 4‐item Stroke Scale (4I‐SS) and validated it in multi‐centers. The 4I‐SS incorporated gaze, level of consciousness, arm weakness, and atrial fibrillation. Receiver operating characteristic analysis was used to compare the 4I‐SS with previously established prehospital prediction scales. Finally, 1630 and 11 440 patients were included in the derivation and validation cohort, respectively. In the validation cohort, Youden Index, area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the 4I‐SS≥4 to predict LVOS were 0.494, 0.800, 0.657, 0.837, 0.600, 0.868, and 0.788, respectively, and that of the 4I‐SS≥7 to predict basilar artery occlusion were 0.200, 0.669, 0.229, 0.971, 0.066, 0.974, and 0.899, respectively. Youden Index and area under the curve were higher than previously published scales for predicting LVOS. Further analysis showed that for predicting whether cardiogenic embolism was the cause, its accuracy was 0.922 when the 4I‐SS score, including atrial fibrillation, was ≥6, and its accuracy of predicting the occluded vessel was intracranial internal carotid artery or M1 segment of the middle cerebral artery when it was ≥7 was 0.590.

Conclusions

The 4I‐SS is an effective and simple tool that can identify LVOS and its cause.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03317639.

High-resolution CT with arch/neck/head CT angiography on a mobile stroke unit

BACKGROUND

Mobile stroke units (MSUs) performance dependability and diagnostic yield of 16-slice, ultra-fast CT with auto-injection angiography (CTA) of the aortic arch/neck/circle of Willis has not been previously reported.

METHODS

We performed a prospective observational study of the first-of-its kind MSU equipped with high resolution, 16-slice CT with multiphasic CTA. Field CT/CTA was performed on all suspected stroke patients regardless of symptom severity or resolution. Performance dependability, efficiency and diagnostic yield over 365 days was quantified.

RESULTS

1031 MSU emergency activations occurred; of these, 629 (61%) were disregarded with unrelated diagnoses, and 402 patients transported: 245 (61%) ischemic or hemorrhagic stroke, 17 (4%) transient ischemic attack, 140 (35%) other neurologic emergencies. Total time from non-contrast CT/CTA start to images ready for viewing was 4.0 (IQR 3.5-4.5) min. Hemorrhagic stroke totaled 24 (10%): aneurysmal subarachnoid hemorrhage 3, hemorrhagic infarct 1, and 20 intraparenchymal hemorrhages (median intracerebral hemorrhage score was 2 (IQR 1-3), 4 (20%) spot sign positive). In 221 patients with ischemic stroke, 73 (33%) received alteplase with 31.5% treated within 60 min of onset. CTA revealed large vessel occlusion in 66 patients (30%) of which 9 (14%) were extracranial; 27 (41%) underwent thrombectomy with onset to puncture time averaging 141±90 min (median 112 (IQR 90-139) min) with full emergency department (ED) bypass. No imaging needed to be repeated for image quality; all patients were triaged correctly with no inter-hospital transfer required.

CONCLUSIONS

MSU use of advanced imaging including multiphasic head/neck CTA is feasible, offers high LVO yield and enables full ED bypass.

Development of Machine Learning Models to Predict Probabilities and Types of Stroke at Prehospital Stage: the Japan Urgent Stroke Triage Score Using Machine Learning (JUST-ML)

In conjunction with recent advancements in machine learning (ML), such technologies have been applied in various fields owing to their high predictive performance. We tried to develop prehospital stroke scale with ML. We conducted multi-center retrospective and prospective cohort study. The training cohort had eight centers in Japan from June 2015 to March 2018, and the test cohort had 13 centers from April 2019 to March 2020. We use the three different ML algorithms (logistic regression, random forests, XGBoost) to develop models. Main outcomes were large vessel occlusion (LVO), intracranial hemorrhage (ICH), subarachnoid hemorrhage (SAH), and cerebral infarction (CI) other than LVO. The predictive abilities were validated in the test cohort with accuracy, positive predictive value, sensitivity, specificity, area under the receiver operating characteristic curve (AUC), and F score. The training cohort included 3178 patients with 337 LVO, 487 ICH, 131 SAH, and 676 CI cases, and the test cohort included 3127 patients with 183 LVO, 372 ICH, 90 SAH, and 577 CI cases. The overall accuracies were 0.65, and the positive predictive values, sensitivities, specificities, AUCs, and F scores were stable in the test cohort. The classification abilities were also fair for all ML models. The AUCs for LVO of logistic regression, random forests, and XGBoost were 0.89, 0.89, and 0.88, respectively, in the test cohort, and these values were higher than the previously reported prediction models for LVO. The ML models developed to predict the probability and types of stroke at the prehospital stage had superior predictive abilities.

Mean Platelet Volume as a Potential Marker of Large Vessel Occlusion and Predictor of Outcome in Acute Ischemic Stroke Patients Treated with Reperfusion Therapy

(1) Background: An early diagnosis of a large vessel occlusion (LVO) is crucial in the management of the acute ischemic stroke (AIS). The laboratory predictors of LVO and a stroke outcome remain unknown. We have hypothesized that high MPV—a surrogate marker of the activated platelet—may be associated with LVO, and it may predict a worse AIS outcome. (2) Methods: This was a retrospective study of 361 patients with AIS who were treated with thrombolysis (tPA, 65.7%) and/or mechanical thrombectomy (MT, 34.3%) in a tertiary Stroke Center between 2011 and 2019. (3) Results: The mean MPV in the cohort was 9.86 ± 1.5 fL (1st–4th quartiles: <8.8, >10.80 fL). Patients in the 4th quartile compared to the 1st had a significantly (p < 0.01) more often incidence of an LVO related stroke (75% vs. 39%) and a severe stroke manifestation with a higher RACE score (5.2 ± 2.8 vs. 3.3 ± 2.4), NIHSS at baseline (mean ± SD, 14 ± 6.5 vs. 10.9 ± 5.2), and NIHSS at discharge (6.9 ± 7 vs. 3.9 ± 3.6). A multivariate analysis revealed that quartiles of MPV (OR 1.4; 95%CI 1.2–1.8) significantly predicted an LVO stroke, also after the adjustment for RACE < 5 (OR 1.4; 95%CI 1.08–1.89), but MPV quartiles did not predict a favorable stroke outcome (mRS ≤ 2) (OR 0.89; 95%CI 0.7–1.13). (4) Conclusion: Our data suggest that MPV is an independent predictor of LVO in patients with an acute ischemic stroke.

Real-World Field Performance of the Los Angeles Motor Scale as a Large Vessel Occlusion Screen: A Prospective Muticentre Study

BACKGROUND

The Los Angeles Motor Scale (LAMS) is a 3-item, 0-to-5-point motor stroke-deficit scale derived from the Los Angeles Prehospital Stroke Screen. We assessed the predictive validity (for interventions performed and discharge disposition) of the LAMS performed in the field by paramedics in a geographic region of over 5,200 km2, covering both rural and urban areas.

METHODS

We analyzed data gathered from Phase I of the LIT-PASS study (Large Vessel Occlusion Identification Through Prehospital Administration of Stroke Scales) which included all patients with suspected acute cerebrovascular disease, as assessed by the Balance, Eyes, Face, Arm, Speech, Terrible Headache/Time to Call 911 (BE-FAST) test.

RESULTS

Among 1,906 patients with median age 72 years (interquartile range [IQR] 60-81), 53% were female with a median on-scene time of 15 min (IQR 12-19). C statistics for the interventions of mechanical thrombectomy, alteplase administration, computed tomography angiography, and perfusion imaging were 0.681, 0.643, and 0.680, respectively. The cut point for predicting these 3 interventions was confirmed to be LAMS ≥ 4. LAMS ≥ 4 had sensitivity 0.730 (0.661-0.790) and specificity 0.570 (0.539-0.601) for mechanical intervention (endovascular thrombectomy, coiling, or clipping) and relative risk of 2.98 (2.19-4.07) for in-hospital death.

CONCLUSIONS

This real-world field study validates the LAMS as an effective tool for prehospital assessment of suspected strokes in determining transport decisions, with predictive validity for interventions performed.

D-Dimer as Predictor of Large Vessel Occlusion in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Improving prehospital triage of large vessel occlusion (LVO) would reduce time to reperfusion therapies. We aimed to study early predictors of LVO in acute ischemic stroke to identify candidates for endovascular treatment.

METHODS

The Stroke-Chip was a prospective observational study conducted at 6 Stroke Centers in Catalonia. Blood samples were obtained in the first 6 hours from symptom onset of consecutive patients. Stroke severity was evaluated with National Institutes of Health Stroke Scale (NIHSS) and LVO was assessed. Independent association of multiple blood biomarkers with LVO was evaluated using logistic regression models adjusted by covariates. Sensitivity, specificity, and predictive values were assessed for NIHSS and the combination of NIHSS and selected serum biomarkers levels.

RESULTS

One thousand three hundred eight suspected strokes were enrolled for a 17-month period. LVO was not assessed in 131 patients. One thousand one hundred seventy-seven patients were selected for analysis (mean age 69.3 years, 56% men, median baseline NIHSS of 6, and median time to blood collection 2.5 hours). LVO was detected in 262 patients. LVO patients were older, had higher baseline NIHSS, history of atrial fibrillation, and lower time from stroke onset to admission. After logistic regression analysis, D-dimer remained an independent predictor of LVO (odds ratio, 1.59 [1.31-1.92]). Specificity and positive predictive value to exclude or detect LVO were higher when using combined D-dimer levels and NIHSS score assessment rather than NIHSS alone.

CONCLUSIONS

Early D-dimer levels are an independent predictor of LVO and may be useful to better optimize prehospital patient transport to the appropriate stroke center.

Comparison of Prehospital Scales for Predicting Large Anterior Vessel Occlusion in the Ambulance Setting

Importance

The efficacy of endovascular thrombectomy (EVT) for symptomatic large anterior vessel occlusion (sLAVO) sharply decreases with time. Because EVT is restricted to comprehensive stroke centers, prehospital triage of patients with acute stroke codes for sLAVO is crucial, and although several prediction scales are already in use, external validation, head-to-head comparison, and feasibility data are lacking.

Objective

To conduct external validation and head-to-head comparisons of 7 sLAVO prediction scales in the emergency medical service (EMS) setting and to assess scale feasibility by EMS paramedics.

Design, Setting, and Participants

This prospective cohort study was conducted between July 2018 and October 2019 in a large urban center in the Netherlands with a population of approximately 2 million people and included 2 EMSs, 3 comprehensive stroke centers, and 4 primary stroke centers. Participants were consecutive patients aged 18 years or older for whom an EMS-initiated acute stroke code was activated. Of 2812 acute stroke codes, 805 (28.6%) were excluded, because no application was used or no clinical data were available, leaving 2007 patients included in the analyses.

Exposures

Applications with clinical observations filled in by EMS paramedics for each acute stroke code enabling reconstruction of the following 7 prediction scales: Los Angeles Motor Scale (LAMS); Rapid Arterial Occlusion Evaluation (RACE); Cincinnati Stroke Triage Assessment Tool; Prehospital Acute Stroke Severity (PASS); gaze-face-arm-speech-time; Field Assessment Stroke Triage for Emergency Destination; and gaze, facial asymmetry, level of consciousness, extinction/inattention.

Main Outcomes and Measures

Planned primary and secondary outcomes were sLAVO and feasibility rates (ie, the proportion of acute stroke codes for which the prehospital scale could be reconstructed). Predictive performance measures included accuracy, sensitivity, specificity, the Youden index, and predictive values.

Results

Of 2007 patients who received acute stroke codes (mean [SD] age, 71.1 [14.9] years; 1021 [50.9%] male), 158 (7.9%) had sLAVO. Accuracy of the scales ranged from 0.79 to 0.89, with LAMS and RACE scales yielding the highest scores. Sensitivity of the scales ranged from 38% to 62%, and specificity from 80% to 93%. Scale feasibility rates ranged from 78% to 88%, with the highest rate for the PASS scale.

Conclusions and Relevance

This study found that all 7 prediction scales had good accuracy, high specificity, and low sensitivity, with LAMS and RACE being the highest scoring scales. Feasibility rates ranged between 78% and 88% and should be taken into account before implementing a scale.

Prediction of acute neurovascular syndromes with prehospital clinical features witnessed by bystanders

BACKGROUND

The prompt recognition of an acute neurovascular syndrome by the patient or a bystander witnessing the event can directly influence outcome. We aimed to study the predictive value of the medical history and clinical features recognized by the patients' bystanders to preclassify acute stroke syndromes in prehospital settings.

METHODS

We analyzed 369 patients: 209 (56.6%) with acute ischemic stroke (AIS), 107 (29.0%) with intracerebral hemorrhage (ICH), and 53 (14.4%) with subarachnoid hemorrhage (SAH). All patients had neuroimaging as diagnostic gold standard. We constructed clinical prediction rules (CPRs) with features recognized by the bystanders witnessing the stroke onset to classify the acute neurovascular syndromes before final arrival to the emergency room (ER).

RESULTS

In all, 83.2% cases were referred from other centers, and only 16.8% (17.2% in AIS, 15% in ICH, and 18.9% in SAH) had direct ER arrival. The time to first assessment in ≤ 3 h occurred in 72.4% (73.7%, 73.8%, and 64.2%, respectively), and final ER arrival in ≤ 3 h occurred in 26.8% (32.1%, 15.9%, and 28.3%, respectively). Clinical features referred by witnesses had low positive predictive values (PPVs) for stroke type prediction. Language or speech disorder + focal motor deficit showed 63.3% PPV, and 77.0% negative predictive value (NPV) for predicting AIS. Focal motor deficit + history of hypertension had 35.9% PPV and 78.8% NPV for ICH. Headache alone had 27.9% PPV and 95.3% NPV for SAH. In multivariate analyses, seizures, focal motor deficit, and hypertension increased the probability of a time to first assessment in ≤ 3 h, while obesity was inversely associated. Final ER arrival was determined by age and a direct ER arrival without previous referrals.

CONCLUSION

CPRs constructed with the witnesses' narrative had only adequate NPVs in the prehospital classification of acute neurovascular syndromes, before neuroimaging confirmation.

Test characteristics of a 5-element cortical screen for identifying anterior circulation large vessel occlusion ischemic strokes

OBJECTIVE

Stroke severity screens typically include cortical signs, such as field cut, aphasia, neglect, gaze preference, and dense hemiparesis (FANG-D). The accuracy and reliability of these signs, when assessed by emergency physicians, to identify patients with anterior circulation large vessel occlusion (ACLVO) acute ischemic stroke (AIS) is unknown. We hypothesized that the FANG-D screen applied by emergency physicians would be sensitive and reliable for identifying ACLVO AIS.

METHODS

We conducted a prospective cohort study enrolling consecutive patients with suspected AIS presenting within 4.5 hours of last known well to the emergency department (ED). Emergency physicians performed the FANG-D screen prior to, and blinded to the results of, imaging. The imaging standard was defined as a non-contrast computed tomography (CT) for identifying hemorrhage and CT angiography for identifying large vessel occlusion. ACLVO was defined as an occlusion of the internal carotid artery, the middle cerebral artery, or its first branch. A convenience sample of patients had a duplicate FANG-D screen performed by a second emergency physician to assess interobserver agreement.

RESULTS

We performed 608 FANG-D assessments on 491 patients presenting to the ED, of whom 64 (10%) had an ACLVO. FANG-D had a sensitivity of 91% (confidence interval [CI] = 81%-96%) and a specificity of 35% (CI = 31%-39%) for identifying ACLVO. Interobserver agreement was tested on 133 patients and was found to be substantial, with a Fleiss' kappa of 0.77 (CI = 0.64-0.88).

CONCLUSIONS

The FANG-D screen is a sensitive test for identifying ACLVO when performed by emergency physicians and demonstrates substantial interrater reliability.

Detailed severity assessment of Cincinnati Prehospital Stroke Scale to detect large vessel occlusion in acute ischemic stroke

Background

Selecting stroke patients with large vessel occlusion (LVO) based on prehospital stroke scales could provide a faster triage and transportation to a comprehensive stroke centre resulting a favourable outcome. We aimed here to explore the detailed severity assessment of Cincinnati Prehospital Stroke Scale (CPSS) to improve its ability to detect LVO in acute ischemic stroke (AIS) patients.

Methods

A cross-sectional analysis was performed in a prospectively collected registry of consecutive patients with first ever AIS admitted within 6 h after symptom onset. On admission stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS) and the presence of LVO was confirmed by computed tomography angiography (CTA) as an endpoint. A detailed version of CPSS (d-CPSS) was designed based on the severity assessment of CPSS items derived from NIHSS. The ability of this scale to confirm an LVO was compared to CPSS and NIHSS respectively.

Results

Using a ROC analysis, the AUC value of d-CPSS was significantly higher compared to the AUC value of CPSS itself (0.788 vs. 0.633, p < 0.001) and very similar to the AUC of NIHSS (0.795, p = 0.510). An optimal cut-off score was found as d-CPSS≥5 to discriminate the presence of LVO (sensitivity: 69.9%, specificity: 75.2%).

Conclusion

A detailed severity assessment of CPSS items (upper extremity weakness, facial palsy and speech disturbance) could significantly increase the ability of CPSS to discriminate the presence of LVO in AIS patients.

A systematic review and meta-analysis to evaluate the diagnostic accuracy of recognition of stroke in the emergency department (ROSIER) scale

BACKGROUND

The present study aims to evaluate the performance and the clinical applicability of the Recognition of Stroke in the Emergency Department (ROSIER) scale via systematic review and meta-analysis.

METHODS

Electronic databases of Pubmed and Embase were searched between 1st January 2005 (when ROSIER developed) and 8th May 2020. Studies that evaluated the diagnostic accuracy of the ROSIER scale were included. The sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) were combined using a bivariate mixed-effects model. Fagan nomogram was used to evaluate the clinical applicability of the ROSIER scale.

RESULTS

A total of 14 studies incorporating 15 datasets were included in this meta-analysis. The combined sensitivity, specificity, DOR and AUC were 0.88 [95% confidence interval (CI): 0.83-0.91], 0.66 (95% CI: 0.52-0.77), 13.86 (95% CI, 7.67-25.07) and 0.88 (95% CI, 0.85-0.90), respectively. Given the pre-test probability of 60.0%, Fagan nomogram suggested the post-test probability was increased to 79% when the ROSIER was positive. In comparison, it was decreased to 22% when ROSIER was negative. Subgroup analysis showed that the pooled sensitivity of ROSIER in the European population was higher than that in Asia. In contrast, the pooled specificity was not significantly different between them. Moreover, results also suggested the male-to-female ratio ≤ 1.0 subgroup, prehospital setting subgroup, and other trained medical personnel subgroup had significantly higher sensitivity compared with their counterparts. At the same time, no significant differences were found in the pooled specificity between them.

CONCLUSIONS

ROSIER is a valid scale with high clinical applicability, which has not only good diagnostic accuracy in Europe but also shows excellent performance in Asia. Moreover, the ROSIER scale exhibits good applicability in prehospital settings with other trained medical personnel.

A potential method of identifying stroke and other intracranial lesions in a prehospital setting

BACKGROUND

Identifying stroke and other intracranial lesions in patients with a decreased level of consciousness may be challenging in prehospital settings. Our objective was to investigate whether the combination of systolic blood pressure, heart rate and age could be used to identify intracranial lesions.

METHODS

We conducted a retrospective case-control study including patients with a decreased level of consciousness who had their airway secured during prehospital care. Patients with intracranial lesions were identified based on the final diagnoses at the end of hospitalization. We investigated the ability of systolic blood pressure, heart rate and age to identify intracranial lesions and derived a decision instrument.

RESULTS

Of 425 patients, 127 had an intracranial lesion. Patients with a lesion were characterized by higher systolic blood pressure, lower heart rate and higher age (P < 0.0001 for all). A systolic blood pressure ≥ 140 mmHg had an odds ratio (OR) of 3.5 (95% confidence interval [CI] 1.7 to 7.0), and > 170 mmHg had an OR of 8.2 (95% CI 4.5-15.32) for an intracranial lesion (reference: < 140 mmHg). A heart rate < 100 beats/min had an OR of 3.4 (95% CI 2.0 to 6.0, reference: ≥100). Age 50-70 had an OR of 4.1 (95% CI 2.0 to 9.0), and > 70 years had an OR of 10.2 (95% CI 4.8 to 23.2), reference: < 50. Logarithms of ORs were rounded to the nearest integer to create a score with 0-2 points for age and blood pressure and 0-1 for heart rate, with an increasing risk for an intracranial lesion with higher scores. The area under the receiver operating characteristics curve for the instrument was 0.810 (95% CI 0.850-0.890).

CONCLUSIONS

An instrument combining systolic blood pressure, heart rate and age may help identify stroke and other intracranial lesions in patients with a decreased level of consciousness in prehospital settings.

TRIAL REGISTRATION

Not applicable.

Stepwise stroke recognition through clinical information, vital signs, and initial labs (CIVIL): Electronic health record-based observational cohort study

BACKGROUND

Stroke recognition systems have been developed to reduce time delays, however, a comprehensive triaging score identifying stroke subtypes is needed to guide appropriate management. We aimed to develop a prehospital scoring system for rapid stroke recognition and identify stroke subtype simultaneously.

METHODS AND FINDINGS

In prospective database of regional emergency and stroke center, Clinical Information, Vital signs, and Initial Labs (CIVIL) of 1,599 patients suspected of acute stroke was analyzed from an automatically-stored electronic health record. Final confirmation was performed with neuroimaging. Using multiple regression analyses, we determined independent predictors of tier 1 (true-stroke or not), tier 2 (hemorrhagic stroke or not), and tier 3 (emergent large vessel occlusion [ELVO] or not). The diagnostic performance of the stepwise CIVIL scoring system was investigated using internal validation. A new scoring system characterized by a stepwise clinical assessment has been developed in three tiers. Tier 1: Seven CIVIL-AS3A2P items (total score from -7 to +6) were deduced for true stroke as Age (≥ 60 years); Stroke risks without Seizure or psychiatric disease, extreme Sugar; "any Asymmetry", "not Ambulating"; abnormal blood Pressure at a cut-off point ≥ 1 with diagnostic sensitivity of 82.1%, specificity of 56.4%. Tier 2: Four items for hemorrhagic stroke were identified as the CIVIL-MAPS indicating Mental change, Age below 60 years, high blood Pressure, no Stroke risks with cut-point ≥ 2 (sensitivity 47.5%, specificity 85.4%). Tier 3: For ELVO diagnosis: we applied with CIVIL-GFAST items (Gaze, Face, Arm, Speech) with cut-point ≥ 3 (sensitivity 66.5%, specificity 79.8%). The main limitation of this study is its retrospective nature and require a prospective validation of the CIVIL scoring system.

CONCLUSIONS

The CIVIL score is a comprehensive and versatile system that recognizes strokes and identifies the stroke subtype simultaneously.

Organizing Healthcare for Optimal Acute Ischemic Stroke Treatment

Stroke is a major health-care problem that represents a leading cause of death and also the top cause of disability in adulthood. In recent years there has been a significant paradigm shift in treatments for acute ischemic stroke to favor earlier reperfusion therapy, mainly using the systemic infusion of recombinant tissue plasminogen activator. Subsequent trials found that combining this treatment with endovascular therapy was effective in selected patients. The increased complexity of acute stroke treatments has resulted in a substantial reorganization of stroke care. This review reports on the evolution of acute ischemic stroke treatment and describes the main organizational models based on the hub-and-spoke system. The lack of evidence for comparisons of the effectiveness of different paradigms means that some decision-analysis models predicting the best organizational pathways are also reported, with a particular emphasis on the workflow timing in the prehospital and in-hospital settings. Major benchmarks and performance measures are also reported, focusing on the timing of interventions and rates of process indicators. Finally, future directions are illustrated, including using telemedicine for stroke, mobile stroke units, and artificial intelligence and automated machines to produce software for detecting large-vessel occlusion.

Management of acute ischemic stroke

Stroke is the leading cause of long term disability in developed countries and one of the top causes of mortality worldwide. The past decade has seen substantial advances in the diagnostic and treatment options available to minimize the impact of acute ischemic stroke. The key first step in stroke care is early identification of patients with stroke and triage to centers capable of delivering the appropriate treatment, as fast as possible. Here, we review the data supporting pre-hospital and emergency stroke care, including use of emergency medical services protocols for identification of patients with stroke, intravenous thrombolysis in acute ischemic stroke including updates to recommended patient eligibility criteria and treatment time windows, and advanced imaging techniques with automated interpretation to identify patients with large areas of brain at risk but without large completed infarcts who are likely to benefit from endovascular thrombectomy in extended time windows from symptom onset. We also review protocols for management of patient physiologic parameters to minimize infarct volumes and recent updates in secondary prevention recommendations including short term use of dual antiplatelet therapy to prevent recurrent stroke in the high risk period immediately after stroke. Finally, we discuss emerging therapies and questions for future research.