Prehospital Triage of Acute Ischemic Stroke Patients to an Intravenous tPA-Ready versus Endovascular-Ready Hospital: A Decision Analysis

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

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

Too risky, too large, too late, or too mild-Reasons for not treating ischemic stroke patients and the related outcomes

Background

Despite effective treatments, many patients are still not offered reperfusion therapy for acute ischemic stroke.

Methods

We present a single-center observational study on acute ischemic stroke patients, who presented as candidates for reperfusion therapy but were deemed ineligible after work-up. Reasons for non-treatment were obtained by studying patient files and subsequently grouped into "too risky" (e.g., anticoagulant use, comorbidities), "too large" (large infarct), "too late" (late presentation of stroke and wake-up strokes), or "too mild" (clinically mild/remitting symptoms). Modified Rankin scale (mRS) score was prospectively collected in all patients by a structured telephone interview. All non-treated patients with a National Institute of Health Stroke Scale (NIHSS) score of 0-5 were compared with a similar cohort that was treated.

Results

Of 529 patients with acute ischemic stroke arriving as reperfusion therapy candidates, 198 (37.4%) were not treated. The majority (42%) were not treated due to admission outside the treatment window (too late) and 24% had absolute contraindications (too risky). Only 8% was excluded because their infarct was too large [median Alberta Stroke Program Early CT score 3 (2-4)]. In the "too mild" group (14%) the percentage of patients not being independent at 90 days was 30%. The adjusted odds ratio for a better outcome (lower mRS) among treated patients with NIHSS 0-5 compared with non-treated was 1.93 (95% confidence interval 1.15-3.23).

Conclusion

Presenting outside the treatment window is still the most common reason for not receiving therapy. Our study suggests a benefit of thrombolysis for patients with mild symptoms.

Advanced imaging in acute ischemic stroke: an updated guide to the hub-and-spoke hospitals

PURPOSE OF REVIEW

The purpose of this review is to summarize the role of the hub-and-spoke system in acute stroke care, highlight the role of advanced imaging and discuss emerging concepts and trials relevant to the hub-and-spoke model.

RECENT FINDINGS

The advent of advanced stroke multimodal imaging has provided increased treatment options for patients, particularly in rural and regional areas. When used in the hub-and-spoke model, advanced imaging can help facilitate and triage transfers, appropriately select patients for acute therapy and treat patients who may otherwise be ineligible based on traditional time metrics.Recent, ongoing trials in this area may lead to an even greater range of patients being eligible for acute reperfusion therapy, including mild strokes and patients with large core infarct volumes.

SUMMARY

Integration of advanced imaging into a hub-and-spoke system, when complemented with other systems including telemedicine, improves access to acute stroke care for patients in regional and rural areas.

Prehospital Evaluation of the FAST-ED as a Secondary Stroke Screen to Identify Large Vessel Occlusion Strokes

Introduction: The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) was developed to identify Large Vessel Occlusion Strokes (LVOS) presenting out of hospital, although there is limited prospective research validating its use in this setting. This study evaluated the test characteristics of the FAST-ED to identify LVOS when used as a secondary stroke screen in the prehospital environment. Secondary analysis compared the performance of the CPSS and the FAST-ED in identifying an LVOS. Methods: This prospective, observational study was conducted from April 2018 to December 2019 in a municipal EMS system with all ALS ambulance response. The FAST-ED was implemented as a secondary screening tool for emergent stroke patients who had at least one positive Cincinnati Prehospital Stroke Screen (CPSS) item. CPSS and FAST-ED scores were extracted from prehospital electronic care reports, while the presence of LVOS was extracted from hospital records. Results: A total 1,359 patients were enrolled; 55.3% female, 47.5% white, with a mean age of 69.4 (SD 15.8). In this cohort, 11.3% of patients experienced an LVOS. The mean FAST-ED for a patient experiencing an LVOS was 5.33 (95%CI 4.97-5.69) compared to 3.06 (95%CI 2.95-3.12) (p < 0.001). A score of greater or equal to 4 yielded the highest combination of sensitivity (77.78%) and specificity (65.34%) with positive likelihood ratio 2.24 (95% CI 2.00-2.52) and negative likelihood ratio 0.34 (95% CI 0.25-0.46). Area under the ROC curve was 0.77 (95%CI 0.73, 0.81). A CPSS with all three items positive demonstrated a sensitivity of 73.20% and 69.57% specificity, with an ROC area of 0.73 (95% CI 0.70-0.77). When comparing a FAST-ED ≥4 to a CPSS of all positive items, there was no significant difference in sensitivity (p > 0.05), and the FAST-ED had a significantly lower specificity than the CPSS (p < 0.005). Conclusion: As stroke care advances, EMS agencies must consider their destination triage needs. This study suggests agencies must consider the use of single versus secondary scales, and to determine the ideal sensitivity and specificity for their system.

The Maryland Acute Stroke Emergency Medical Services Routing Pilot: Expediting Access to Thrombectomy for Stroke

Background: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke caused by large vessel occlusion, but is not available at all stroke centers. Transfers between hospitals lead to treatment delays. Transport directly to a facility capable of MT based on a prehospital stroke severity scale score has been recommended, if transportation time is less than 30 min.

Aims: We hypothesized that an Emergency Medical Services (EMS) routing algorithm for stroke, using the Los Angeles Motor Scale (LAMS) in the field, would improve time from last known well to MT, without causing patients to miss the IV Thrombolysis (IVT) window.

Methods: An EMS algorithm in the Baltimore metro area using the LAMS was implemented. Patients suspected of having an acute stroke were assessed by EMS using the LAMS. Patients scoring 4 or higher and within 20 h from last known well, were transported directly to a Thrombectomy Center, if transport could be completed within 30 min. The algorithm was evaluated retrospectively with prospectively collected data at the Thrombectomy Centers. The primary outcome variables were proportion of patients with suspected stroke rerouted by EMS, proportion of rerouted ischemic stroke patients receiving MT, time to treatment, and whether the IVT window was missed.

Results: A total of 303 patients were rerouted out of 2459 suspected stroke patients over a period of 6 months. Of diverted patients, 47% had acute ischemic stroke. Of these, 48% received an acute stroke treatment: 16.8% IVT, 17.5% MT, and 14% MT+IVT. Thrombectomy occurred 119 min earlier in diverted patients compared to patients transferred from other hospitals (P = 0.006). 55.3% of diverted patients undergoing MT and 38.2% of patients transferred from hospital to hospital were independent at 90 days (modified Rankin score 0–2) (P = 0.148). No patient missed the time window for IVT due to the extra travel time.

Conclusions: In this retrospective analysis of prospectively acquired data, implementation of a pre-hospital clinical screening score to detect patients with suspected acute ischemic stroke due to large vessel occlusion was feasible. Rerouting patients directly to a Thrombectomy Center, based on the EMS algorithm, led to a shorter time to thrombectomy.

Predicting neuroimaging eligibility for extended-window endovascular thrombectomy

OBJECTIVE

Endovascular thrombectomy (EVT) and tissue plasminogen activator (tPA) are effective ischemic stroke treatments in the initial treatment window. In the extended treatment window, these treatments may offer benefit, but CT and MR perfusion may be necessary to determine patient eligibility. Many hospitals do not have access to advanced imaging tools or EVT capability, and further patient care would require transfer to a facility with these capabilities. To assist transfer decisions, the authors developed risk indices that could identify patients eligible for extended-window EVT or tPA.

METHODS

The authors retrospectively identified stroke patients who had concurrent CTA and perfusion and evaluated three potential outcomes that would suggest a benefit from patient transfer. The first outcome was large-vessel occlusion (LVO) and target mismatch (TM) in patients 5-23 hours from last known normal (LKN). The second outcome was TM in patients 5-15 hours from LKN with known LVO. The third outcome was TM in patients 4.5-12 hours from LKN. The authors created multivariable models using backward stepping with an α-error criterion of 0.05 and assessed them using C statistics.

RESULTS

The final predictors included the National Institutes of Health Stroke Scale (NIHSS), the Alberta Stroke Program Early CT Score (ASPECTS), and age. The prediction of the first outcome had a C statistic of 0.71 (n = 145), the second outcome had a C statistic of 0.85 (n = 56), and the third outcome had a C statistic of 0.86 (n = 54). With 1 point given for each predictor at different cutoffs, a score of 3 points had probabilities of true positive of 80%, 90%, and 94% for the first, second, and third outcomes, respectively.

CONCLUSIONS

Despite the limited sample size, compared with perfusion-based examinations, the clinical variables identified in this study accurately predicted which stroke patients would have salvageable penumbra (C statistic 71%-86%) in a range of clinical scenarios and treatment cutoffs. This prediction improved (C statistic 85%-86%) when utilized in patients with confirmed LVO or a less stringent tissue mismatch (TM < 1.2) cutoff. Larger patient registries should be used to validate and improve the predictive ability of these models.

Early Thrombectomy Outcomes in Transfer Patients

OBJECTIVE

The optimal patient transportation destination of acute ischemic stroke (AIS) patients remains uncertain. The purpose of this study was to evaluate the predictive variables that determine stroke outcomes depending on the patient transportation destination.

METHODS

We performed a retrospective study using an AIS database consisting of patients who underwent thrombectomy admitted to our institution from November 1, 2011, through October 1, 2018.

RESULTS

A total of 171 patients were included in the statistical analysis; 42.1% (72/171) of patients were in the mothership group (directly admitted) and 57.9% (99/171) in the drip-and-ship group (transferred). Multivariable logistic regression revealed the predictive factors for favorable outcomes were driving distance (expressed in miles) between the patient's home and a comprehensive stroke center (CSC) (odds ratio [OR] = 0.95; 95% confidence interval [CI], 0.90-0.99; P = .035), absence of diabetes mellitus (OR = 3.60; 95% CI, 1.20-10.82; P = .022), lower National Institutes of Health Stroke Scale score at admission (OR = 0.91; 95% CI, 0.85-0.97; P = .003), and shorter symptom onset to CSC arrival time (expressed in hours) (OR = 0.84; 95% CI, 0.72-0.99; P = .038).

CONCLUSIONS

Our study revealed that a shorter driving distance between the patient's home and CSC, absence of diabetes, lower National Institutes of Health Stroke Scale score, and shorter onset to hospital arrival time positively impacted the outcomes of endovascularly treated AIS patients.

Inter-Rater Reliability of the FAST-ED in the Out-of-Hospital Setting

Introduction: Patients experiencing a large vessel occlusion stroke (LVOS) may require endovascular-capable centers and benefit from direct transport to such facilities, creating a need for an accurate prehospital assessment. The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) is a secondary scale to identify LVOS. Currently, there is limited prospective evidence validating the use of the FAST-ED in the prehospital environment. This study aimed to evaluate the inter-rater reliability of the FAST-ED between patient care providers in the prehospital setting.Methods: This prospective study was conducted between 4/1/2018 and 7/1/2018 in a single municipal EMS agency that staffs two providers per ambulance with at least one being a paramedic. Patients were included based on paramedic impression that the patient was both having a stroke and greater than 18 years old. Each provider independently performed and documented a FAST-ED assessment on eligible patients. Data analysis consisted of performing inter-rater reliability using Cohen's Kappa on the FAST-ED score between primary and secondary providers. The FAST-ED was analyzed on an item level, an aggregate level (cumulative of all items), and using the defined cut point of ≥4. A sub-analysis determined if inter-rater reliability changed across provider certification.Results: There were 231 patients included in this analysis with an average age of 68.5 years and 135 (58.4%) female. Inter-rater reliability varied across individual items in the scale from 90.1% agreement to 82.5%. When analyzing inter-rater reliability of the aggregate FAST-ED score, the scale demonstrated 70.1% agreement (Kappa 0.66), considered substantial agreement. FAST-ED scores were analyzed using a cut point of ≥4. When using this cut point, there was 92.2% (Kappa 0.81) agreement between primary and secondary caregiver, demonstrating almost perfect agreement. Agreement was substantial across provider certifications including paramedics and EMTS.Conclusion: This study demonstrated high inter-rater reliability of the FAST-ED scale when performed in the prehospital setting on patients suspected of having a stroke. There were minimal differences in reliability based on provider certification, and item level analysis indicated substantial inter-rater reliability.

Design and Derivation of the Austrian Prehospital Stroke Scale (APSS) to Predict Severe Stroke with Large Vessel Occlusion

Objectives: Prediction of large vessel occlusion (LVO) is highly relevant for accurate prehospital transportation triage. The Austrian Prehospital Stroke Scale (APSS) score for LVO prediction was developed using critical synthesis of previously published LVO-scores. The aim of this study was to investigate the accuracy of the APSS and compare it to other LVO-scores. Methods: APSS consists of 5 items: "facial palsy," "motor arm," "language," "motor leg" and "gaze deviation." The score ranges from 0 to 9 points. Data from 741 consecutive stroke patients with acute vessel imaging admitted to an independent comprehensive stroke center was used to test the predictive performance of the APSS in context of other LVO-scores (CPSS, FAST-ED, G-FAST, sNIHSS-EMS and RACE). Results: In the prediction of treatable LVO the APSS showed the highest area under the curve (0.834) with significant difference to CPSS (p = 0.010) and G-FAST (p = 0.006) and showed highest sensitivity (69%) as compared to other LVO scores. Specificity (85%), positive predictive value (75%), negative predictive value (81%) and accuracy (79%) were comparable to other LVO scores. Receiver operating curve analysis revealed an optimal cutoff for LVO prediction at APSS equal to 4 points. Conclusions: The easy assessable 5-item APSS score tended to outperform other LVO scores. Real-life prospective evaluation in prehospital setting is ongoing.

Recanalization Therapy for Acute Ischemic Stroke with Large Vessel Occlusion: Where We Are and What Comes Next?

In the past 5 years, the success of multiple randomized controlled trials of recanalization therapy with endovascular thrombectomy has transformed the treatment of acute ischemic stroke with large vessel occlusion. The evidence from these trials has now established endovascular thrombectomy as standard of care. This review will discuss the chronological evolution of large vessel occlusion treatment from early medical therapy with tissue plasminogen activator to the latest mechanical thrombectomy. Additionally, it will highlight the potential areas in endovascular thrombectomy for acute ischemic stroke open to exploration and further progress in the next decade.

Prehospital Triage Strategies for the Transportation of Suspected Stroke Patients in the United States

Background and Purpose:

Ischemic stroke patients with large vessel occlusion (LVO) could benefit from direct transportation to an intervention center for endovascular treatment, but non-LVO patients need rapid IV thrombolysis in the nearest center. Our aim was to evaluate prehospital triage strategies for suspected stroke patients in the United States.

Methods:

We used a decision tree model and geographic information system to estimate outcome of suspected stroke patients transported by ambulance within 4.5 hours after symptom onset. We compared the following strategies: (1) Always to nearest center, (2) American Heart Association algorithm (ie, directly to intervention center if a prehospital stroke scale suggests LVO and total driving time from scene to intervention center is <30 minutes, provided that the delay would not exclude from thrombolysis), (3) modified algorithms with a maximum additional driving time to the intervention center of <30 minutes, <60 minutes, or without time limit, and (4) always to intervention center. Primary outcome was the annual number of good outcomes, defined as modified Rankin Scale score of 0–2. The preferred strategy was the one that resulted in the best outcomes with an incremental number needed to transport to intervention center (NNTI) <100 to prevent one death or severe disability (modified Rankin Scale score of >2).

Results:

Nationwide implementation of the American Heart Association algorithm increased the number of good outcomes by 594 (+1.0%) compared with transportation to the nearest center. The associated number of non-LVO patients transported to the intervention center was 16 714 (NNTI 28). The modified algorithms yielded an increase of 1013 (+1.8%) to 1369 (+2.4%) good outcomes, with a NNTI varying between 28 and 32. The algorithm without time limit was preferred in the majority of states (n=32 [65%]), followed by the algorithm with <60 minutes delay (n=10 [20%]). Tailoring policies at county-level slightly reduced the total number of transportations to the intervention center (NNTI 31).

Conclusions:

Prehospital triage strategies can greatly improve outcomes of the ischemic stroke population in the United States, but increase the number of non-LVO stroke patients transported to an intervention center. The current American Heart Association algorithm is suboptimal as a nationwide policy and should be modified to allow more delay when directly transporting LVO-suspected patients to an intervention center.

Blood product transfusion during air medical transport: A needs assessment

Objectives

Early administration of blood products to patients with hemorrhagic shock has a positive impact on morbidity and mortality. Smaller hospitals may have limited supply of blood, and air medical systems may not carry blood. The primary outcome is to quantify the number of patients meeting established physiologic criteria for blood product administration and to identify which patients receive and which ones do not receive it due to lack of availability locally.

Methods

Electronic patient care records were used to identify a retrospective cohort of patients undergoing emergent air medical transport in Ontario, Canada, who are likely to require blood. Presenting problems for blood product administration were identified. Physiologic data were extracted with criteria for transfusion used to identify patients where blood product administration is indicated.

Results

There were 11,520 emergent patient transports during the study period, with 842 (7.3%) where blood product administration was considered. Of these, 290 met established physiologic criteria for blood products, with 167 receiving blood, of which 57 received it at a hospital with a limited supply. The mean number of units administered per patient was 3.5. The remaining 123 patients meeting criteria did not receive product because none was unavailable.

Conclusion

Indications for blood product administration are present in 2.5% of patients undergoing time-sensitive air medical transport. Air medical services can enhance access to potentially lifesaving therapy in patients with hemorrhagic shock by carrying blood products, as blood may be unavailable or in limited supply locally in the majority of patients where it is indicated.

Epidemiology, Natural History, and Clinical Presentation of Large Vessel Ischemic Stroke

Large vessel occlusions (LVOs), variably defined as blockages of the proximal intracranial anterior and posterior circulation, account for approximately 24% to 46% of acute ischemic strokes. Commonly refractory to intravenous tissue plasminogen activator (tPA), LVOs place large cerebral territories at ischemic risk and cause high rates of morbidity and mortality without further treatment. Over the past few years, an abundance of high-quality data has demonstrated the efficacy of endovascular thrombectomy for improving clinical outcomes in patients with LVOs, transforming the treatment algorithm for affected patients. In this review, we discuss the epidemiology, pathophysiology, natural history, and clinical presentation of LVOs as a framework for understanding the recent clinical strides of the endovascular era.

Factors delaying intravenous thrombolytic therapy in acute ischaemic stroke: a systematic review of the literature

BACKGROUND/AIMS

This review examined factors that delay thrombolysis and what management strategies are currently employed to minimise this delay, with the aim of suggesting future directions to overcome bottlenecks in treatment delivery.

METHODS

A systematic review was performed according to PRISMA guidelines. The search strategy included a combination of synonyms and controlled vocabularies from Medical Subject Headings (MeSH) and EmTree covering brain ischemia, cerebrovascular accident, fibrinolytic therapy and Alteplase. The search was conducted using Medline (OVID), Embase (OVID), PubMed and Cochrane Library databases using truncations and Boolean operators. The literature search excluded review articles, trial protocols, opinion pieces and case reports. Inclusion criteria were: (1) The article directly related to thrombolysis in ischaemic stroke, and (2) The article examined at least one factor contributing to delay in thrombolytic therapy.

RESULTS

One hundred and fifty-two studies were included. Pre-hospital factors resulted in the greatest delay to thrombolysis administration. In-hospital factors relating to assessment, imaging and thrombolysis administration also contributed. Long onset-to-needle times were more common in those with atypical, or less severe, symptoms, the elderly, patients from lower socioeconomic backgrounds, and those living alone. Various strategies currently exist to reduce delays. Processes which have achieved the greatest improvements in time to thrombolysis are those which integrate out-of-hospital and in-hospital processes, such as the Helsinki model.

CONCLUSION

Further integrated processes are required to maximise patient benefit from thrombolysis. Expansion of community education to incorporate less common symptoms and provision of alert pagers for patients may provide further reduction in thrombolysis times.

Bypassing the Closest Stroke Center for Thrombectomy Candidates

Background and Purpose—

Patients with acute ischemic stroke who have large vessel occlusion benefit from direct transport to a comprehensive stroke center (CSC) capable of endovascular therapy. To avoid harm for patients without large vessel occlusion from delayed access to intravenous thrombolysis (IVT), it has been suggested to only redirect patients with high likelihood of large vessel occlusion for whom the additional delay to intravenous thrombolysis (IVT) caused by transport to the CSC is below a certain threshold. However, which threshold achieves the greatest clinical benefit is unknown.

Methods—

We used mathematical modeling to calculate additional-delay-to-IVT thresholds associated with the greatest reduction in disability-adjusted life years in abstracted 2-stroke center and multiple-stroke center scenarios. Model parameters were extracted from recent meta-analyses or large prospective cohort studies. Uncertainty was quantified in probabilistic and 2-way univariate sensitivity analyses.

Results—

Assuming ideal treatment time performance metrics, transport to the nearest CSC was the preferred strategy irrespective of additional delay-to-IVT when the transfer time between primary stroke center and CSC was <40 minutes (95% credible interval: 25–66 minutes); otherwise, the optimal additional delay-to-IVT-threshold ranged from 28 to 139 minutes. In multiple-stroke center scenarios, optimal additional-delay-to-IVT thresholds were 30 to 54 minutes in urban and 49 to 141 minutes in rural settings; use of optimal thresholds as compared with a 15 minute-threshold saved 0 to 0.11 and 0 to 0.37 disability-adjusted life years per triage case, respectively. Assuming slower treatment times at primary stroke centers and CSCs yielded longer permissible additional delays.

Conclusions—

Our results suggest that patients with acute ischemic stroke with suspected large vessel occlusion should be redirected to a CSC if the additional delay to IVT is <30 minutes in urban and 50 minutes in rural settings.

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.

Effect of Interhospital Transfer on Endovascular Treatment for Acute Ischemic Stroke

Background and Purpose- To assess the effect of inter-hospital transfer on time to treatment and functional outcome after endovascular treatment (EVT) for acute ischemic stroke, we compared patients transferred from a primary stroke center to patients directly admitted to an intervention center in a large nationwide registry. Methods- MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry is an ongoing, prospective, observational study in all centers that perform EVT in the Netherlands. We included adult patients with an acute anterior circulation stroke who received EVT between March 2014 to June 2016. Primary outcome was time from arrival at the first hospital to arterial groin puncture. Secondary outcomes included the 90-day modified Rankin Scale score and functional independence (modified Rankin Scale score of 0-2). Results- In total 821/1526 patients, (54%) were transferred from a primary stroke center. Transferred patients less often had prestroke disability (227/800 [28%] versus 255/699 [36%]; P=0.02) and more often received intravenous thrombolytics (659/819 [81%] versus 511/704 [73%]; P<0.01). Time from first presentation to groin puncture was longer for transferred patients (164 versus 104 minutes; P<0.01, adjusted delay 57 minutes [95% CI, 51-62]). Transferred patients had worse functional outcome (adjusted common OR, 0.75 [95% CI, 0.62-0.90]) and less often achieved functional independence (244/720 [34%] versus 289/681 [42%], absolute risk difference -8.5% [95% CI, -8.7 to -8.3]). Conclusions- Interhospital transfer of patients with acute ischemic stroke is associated with delay of EVT and worse outcomes in routine clinical practice, even in a country where between-center distances are short. Direct transportation of patients potentially eligible for EVT to an intervention center may improve functional outcome.

Decision Analysis Model for Prehospital Triage of Patients With Acute Stroke

Background and Purpose- We used a decision analysis approach to analyze triage strategies for patients with acute stroke symptoms while accounting for prehospital large vessel occlusion (LVO) screening methods and key time metrics. Methods- Our decision analysis compared anticipated functional outcomes for patients within the IV-tPA (intravenous tissue-type plasminogen activator) treatment window in the mothership and drip-and-ship frameworks. Key branches of the model included IV-tPA eligibility, presence of an LVO, and endovascular therapy eligibility. Our decision analysis evaluated 2 prehospital LVO screening approaches: (1) no formal screening and (2) the use of clinical LVO screening scales. An excellent outcome was defined as modified Rankin Scale scores 0-1. Probabilities and workflow times were guideline-based or imputed from published studies. In sensitivity analyses, we individually and jointly varied transport time to the nearest primary stroke center, additional time required to transport directly to a comprehensive stroke center, and LVO screening scale predictive probabilities. We evaluated 2 separate scenarios: one in which ideal time metrics were achieved and one under current real-world metrics. Results- In the ideal metrics scenario, the drip-and-ship strategy was almost always favored in the absence of formal LVO screening. For patients screened positive for an LVO, mothership was favored if the additional transport time to the comprehensive stroke center was <3 to 23 minutes. Under real-world conditions, in which primary stroke center workflow is slower than ideal, the mothership strategy was favored in more scenarios, regardless of formal LVO screening. For example, mothership was favored with an additional transport time to the comprehensive stroke center of <32 to 99 minutes for patients screened positive for an LVO and <28 to 39 minutes in the absence of screening. Conclusions- Joint consideration of LVO probability, screening, workflow times, and transport times may improve prehospital stroke triage. Drip-and-ship was more favorable when more ideal primary stroke center workflow times were modeled.

Personalized Prehospital Triage in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Background and Purpose—

Direct transportation to a center with facilities for endovascular treatment might be beneficial for patients with acute ischemic stroke, but it can also cause harm by delay of intravenous treatment. Our aim was to determine the optimal prehospital transportation strategy for individual patients and to assess which factors influence this decision.

Methods—

We constructed a decision tree model to compare outcome of ischemic stroke patients after transportation to a primary stroke center versus a more distant intervention center. The optimal strategy was estimated based on individual patient characteristics, geographic location, and workflow times. In the base case scenario, the primary stroke center was located at 20 minutes and the intervention center at 45 minutes. Additional sensitivity analyses included an urban scenario (10 versus 20 minutes) and a rural scenario (30 versus 90 minutes).

Results—

Direct transportation to the intervention center led to better outcomes in the base case scenario when the likelihood of a large vessel occlusion as a cause of the ischemic stroke was >33%. With a high likelihood of large vessel occlusion (66%, comparable with a Rapid Arterial Occlusion Evaluation score of 5 or above), the benefit of direct transportation to the intervention center was 0.10 quality-adjusted life years (=36 days in full health). In the urban scenario, direct transportation to an intervention center was beneficial when the risk of large vessel occlusion was 24% or higher. In the rural scenario, this threshold was 49%. Other factors influencing the decision included door-to-needle times, door-to-groin times, and the door-in-door-out time.

Conclusions—

The preferred prehospital transportation strategy for suspected stroke patients depends mainly on the likelihood of large vessel occlusion, driving times, and in-hospital workflow times. We constructed a robust model that combines these characteristics and can be used to personalize prehospital triage, especially in more remote areas.

Field triage for endovascular stroke therapy: a population-based comparison

Background

Endovascular therapy (EVT) for stroke improves outcomes but is time sensitive.

Objective

To compare times to treatment and outcomes between patients taken to the closest primary stroke center (PSC) with those triaged in the field to a more distant comprehensive stroke center (CSC).

Methods

During the study, a portion of our region allowed field triage of patients who met severity criteria to a more distant CSC than the closest PSC. The remaining patients were transported to the closest PSC. We compared times to treatment and clinical outcomes between those two groups. Additionally, we performed a matched-pairs analysis of patients from both groups on stroke severity and distance to CSC.

Results

Over 2 years, 232 patients met inclusion criteria and were closest from the field to a PSC; 144 were taken to the closest PSC and 88 to the more distant CSC. The median additional transport time to the CSC was 7 min. Times from scene departure to alteplase and arterial puncture were faster in the direct group (50 vs 62 min; 93 vs 152 min; p<0.001 for both). Among patients who were independent before the stroke, the OR for less disability in the direct group was 1.47 (95% CI 1.13 to 1.93, p=0.003), and 2.06 (95% CI 1.10 to 3.89, p=0.01) for the matched pairs.

Conclusions

In a densely populated setting, for patients with stroke who are EVT candidates and closest to a PSC from the field, triage to a slightly more distant CSC is associated with faster time to EVT, no delay to alteplase, and less disability at 90 days.

Availability of Hospital Resources and Specialty Services for Stroke Care in North Carolina

OBJECTIVES

Effective regionalization of acute stroke care requires assessment and coordination of limited hospital resources. We described the availability of stroke-specific hospital resources (neurology specialty physicians and neuro-intensive care unit [neuro-ICU] bed capacity) for North Carolina overall and by region and population density. We also assessed daily trends in hospital bed availability.

METHODS

This statewide descriptive study was conducted with data from the State Medical Asset Resource Tracking Tool (SMARTT), a Web-based system used by North Carolina to track available medical resources within the state. The SMARTT system was queried for stroke-specific physician and bed resources at each North Carolina hospital during a 1-year period (June 2015-May 2016), including daily availability of neuro-ICU beds. We compared hospital resources by geographic region and population density (metropolitan, urban, and rural).

RESULTS

Data from 108 acute care hospitals located in 75 of 100 counties in North Carolina were included in the analysis. Fifty-seven percent of hospitals had no neurology specialty physicians. Western and eastern North Carolina had the lowest prevalence of these physicians. Most hospitals (88%) had general ICUs, whereas only 17 hospitals (16%) had neuro-ICUs. Neuro-ICUs were concentrated in metropolitan areas and in central North Carolina. On average, there were 276 general ICU and 27 neuro-ICU beds available statewide each day. Daily neuro-ICU bed availability was lowest in eastern and southeastern regions and during the week compared with weekends.

CONCLUSIONS

In North Carolina, stroke-specific hospital subspecialists and resources are not distributed evenly across the state. Daily bed availability, particularly in neuro-ICUs, is lacking in rural areas and noncentral regions and appears to decrease on weekdays. Regionalization of stroke care needs to consider the geographic distribution and daily variability of hospital resources.