Establishing the First Mobile Stroke Unit in the United States

Intravenous thrombolysis for acute ischemic stroke: a bridge between two centuries

INTRODUCTION

Intravenous tissue-plasminogen activator (tPA) remains the only approved systemic reperfusion therapy suitable for most patients presenting timely with acute ischemic stroke. Accumulating real-word experience for over 20 years regarding tPA safety and effectiveness led to re-appraisal of original contraindications for intravenous thrombolysis (IVT). Areas covered: This narrative review focuses on fast yet appropriate selection of patients for safe administration of tPA per recently expanded indications. Novel strategies for rapid patient assessment will be discussed. The potential for mobile stroke units (MSU) that shorten onset-to-needle time and increase tPA treatment rates is addressed. The use of IVT in the era of non-vitamin K antagonist oral anticoagulants (NOACs) is highlighted. The continuing role of IVT in large vessel occlusion (LVO) patients eligible for mechanical thrombectomy (MT) is discussed with regards to 'drip and ship' vs. 'mothership' treatment paradigms. Promising studies of penumbral imaging to extend IVT beyond the 4.5-hour window and in wake-up strokes are summarized. Expert commentary: This review provides an update on the role of IVT in specific conditions originally considered tPA contraindications. Novel practice challenges including NOAC's, MSU proliferation and bridging therapy (IVT&MT) for LVO patients, and the potential extension of IVT time-window using penumbral imaging are emerging as safe and potentially effective IVT applications.

Review of the Mobile Stroke Unit Experience Worldwide

Background

The treatment of stroke is dependent on a narrow therapeutic time window that requires interventions to be emergently pursued. Despite recent "FAST" initiatives that have underscored "time is brain," many patients still fail to present within the narrow time window to receive maximum treatment benefit from advanced stroke therapies, including recombinant tissue plasminogen activator (tPA) and mechanical thrombectomy. The convergence of emergency medical services, telemedicine, and mobile technology, including transportable computed tomography scanners, has presented a unique opportunity to advance patient stroke care in the prehospital field by shortening time to hyperacute stroke treatment with a mobile stroke unit (MSU).

Summary

In this review, we provide a look at the evolution of the MSU into its current status as well as future directions. Our summary statement includes historical and implementation information, economic cost, and published clinical outcome and time metrics, including the utilization rate of thrombolysis.

Key Messages

Initially hypothesized in 2003, the first MSUs were launched in Germany and adopted worldwide in acute, prehospital stroke management. These specialized ambulances have made the diagnosis and treatment of many neurological emergencies, in addition to ischemic and hemorrhagic stroke, possible at the emergency site. Providing treatment as early as possible, including within the prehospital phase of stroke management, improves patient outcomes. As MSUs continue to collect data and improve their methods, shortened time metrics are expected, resulting in more patients who will benefit from faster treatment of their acute neurological emergencies in the prehospital field.

Time to Decision and Treatment With tPA (Tissue-Type Plasminogen Activator) Using Telemedicine Versus an Onboard Neurologist on a Mobile Stroke Unit

BACKGROUND AND PURPOSE

Mobile stroke units (MSUs) can speed treatment with intravenous tPA (tissue-type plasminogen activator). We previously showed substantial agreement between a telemedicine-based vascular neurologist (TM-VN) and an onboard vascular neurologist (OB-VN) for the evaluation of patients with stroke for tPA eligibility on an MSU. However, the time efficiency of the telemedicine-based evaluation remained uncertain. In this study, we examined the speed of decision and treatment from MSU arrival for the TM-VN compared with an OB-VN.

METHODS

In 50 consecutive situations, the TM-VN served as the primary decision maker. Times from MSU arrival to tPA decision and tPA bolus were compared with the same metrics for when the OB-VN served as the primary decision maker.

RESULTS

Time to tPA decision for the TM-VN was 21 minutes (interquartile range, 16.25-26) versus 18 minutes (interquartile range, 14-22) for the OB-VN (P=0.01). Initiation of tPA bolus was 24 minutes (interquartile range, 19.75-30) for the TM-VN versus 24 minutes (interquartile range, 19-27.75) for the OB-VN (P=0.5).

CONCLUSIONS

Assessment by a TM-VN is comparable with an OB-VN in making decisions about tPA administration on an MSU and does not lead to treatment delays.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02190500.

Thrombolysis in stroke patients: Comparability of point-of-care versus central laboratory international normalized ratio

BACKGROUND

In acute stroke patients, thrombolysis is one gold standard therapy option within the first four hours after the ischemic event. A contraindication for thrombolysis is an International Normalized Ratio (INR) value >1.7. Since time is brain, rapid and reliable INR results are fundamental. Aim was to compare INR values determined by central laboratory (CL) analyzer and Point-of-Care Testing(POCT)-device and to evaluate the quality of POCT performance in cases of potential therapeutic thrombolysis at a certified stroke unit.

METHODS

In 153 patients INR measurements using POCT-devices (HEMOCHRON Signature Elite®) were compared to INR measurements (BCS®XP) performed at the central laboratory. Outlier evaluation was performed regarding the critical thrombolysis cut-off.

RESULTS

Overall, we demonstrated a significant correlation (r = 0.809, p<0.0001) between both measurement methods. Mean value of the absolute difference between CL-INR and POCT-INR measurements was 0.23. In 95.4% of these cases, no differences regarding the critical cut-off (INR 1.7) were observed. POCT-INR values tended to be higher than the CL-INR values (p = 0.01). In 4.6% cases, a different value regarding thrombolysis cut-off was found. All patients were >75 years.

CONCLUSIONS

POCT-INR measurements based on our POCT concept are suitable to determine INR values in critical stroke patients. Nevertheless, outlier evaluation is mandatory.

The PRE-hospital Stroke Treatment Organization

Background

The PRE-hospital Stroke Treatment Organization was formed in 2016 as an international consortium of medical practitioners involved in pre-hospital treatment of patients with acute stroke.

Aims

PRE-hospital Stroke Treatment Organization’s mission is to improve stroke outcomes by supporting research and advocacy for pre-hospital stroke treatment in Mobile Stroke Units. PRE-hospital Stroke Treatment Organization will provide a platform to enhance collaborative research across the spectrum of acute stroke management in the pre-hospital setting. PRE-hospital Stroke Treatment Organization will also facilitate the appropriate proliferation and distribution of Mobile Stroke Units by providing a forum for professional communication, resource for public education, and stimulus for government, industry, and philanthropic support.

Summary of review

In this “white paper”, we describe the evidence supporting pre-hospital stroke treatment, progress to date, practical issues such as application in various environments and staffing, planned research initiatives, and organizational structure.

Conclusions

PRE-hospital Stroke Treatment Organization is not-for-profit, with membership open to anyone involved (or hoping to become involved) in pre-hospital stroke care. PRE-hospital Stroke Treatment Organization has a Steering Committee comprised of members from Europe, U.S., Canada, Australia, and other regions having a Mobile Stroke Unit in operation. PRE-hospital Stroke Treatment Organization convenes satellite meetings for membership at the International Stroke Conference and European Stroke Congress each year to address the PRE-hospital Stroke Treatment Organization mission. The first research collaborations agreed upon are to: (1) develop a list of common data elements to be collected by all Mobile Stroke Unit programs and entered into a common research database, and (2) develop a protocol for investigating the natural history of hyper-acute Intracerebral Hemorrhage.

Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest

Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.

Identifying Key Words in 9-1-1 Calls for Stroke: A Mixed Methods Approach

OBJECTIVES

Identifying stroke during a 9-1-1 call is critical to timely prehospital care. However, emergency medical dispatchers (EMDs) recognize stroke in less than half of 9-1-1 calls, potentially due to the words used by callers to communicate stroke signs and symptoms. We hypothesized that callers do not typically use words and phrases considered to be classical descriptors of stroke, such as focal neurologic deficits, but that a mixed-methods approach can identify words and phrases commonly used by 9-1-1 callers to describe acute stroke victims.

METHODS

We performed a mixed-method, retrospective study of 9-1-1 call audio recordings for adult patients with confirmed stroke who were transported by ambulance in a large urban city. Content analysis, a qualitative methodology, and computational linguistics, a quantitative methodology, were used to identify key words and phrases used by 9-1-1 callers to describe acute stroke victims. Because a caller's level of emotional distress contributes to the communication during a 9-1-1 call, the Emotional Content and Cooperation Score was scored by a multidisciplinary team.

RESULTS

A total of 110 9-1-1 calls, received between June and September 2013, were analyzed. EMDs recognized stroke in 48% of calls, and the emotional state of most callers (95%) was calm. In 77% of calls in which EMDs recognized stroke, callers specifically used the word "stroke"; however, the word "stroke" was used in only 38% of calls. Vague, non-specific words and phrases were used to describe stroke victims' symptoms in 55% of calls, and 45% of callers used distractor words and phrases suggestive of non-stroke emergencies. Focal neurologic symptoms were described in 39% of calls. Computational linguistics identified 9 key words that were more commonly used in calls where the EMD identified stroke. These words were concordant with terms identified through qualitative content analysis.

CONCLUSIONS

Most 9-1-1 callers used vague, non-specific, or distractor words and phrases and infrequently provide classic stroke descriptions during 9-1-1 calls for stroke. Both qualitative and quantitative methodologies identified similar key words and phrases associated with accurate EMD stroke recognition. This study suggests that tools incorporating commonly used words and phrases could potentially improve EMD stroke recognition.

Electrochemical impedimetric detection of stroke biomarker NT-proBNP using disposable screen-printed gold electrodes

Stroke is the second top leading cause of death globally. It is caused by an abrupt interruption of blood flow to the brain. In that course, brain natriuretic peptide (BNP) and its derivative N-terminal pro b-type natriuretic peptide (NT-proBNP), neurohormones produced mainly by the heart ventricles in response to excessive stretching of cardiomyocytes (heart muscle cells), are proven to be good biomarkers for heart failure diagnosis. Moreover, there is growing clinical interest of the use of NT-proBNP for stroke diagnosis and prognosis because it is significantly associated with cardioembolic stroke and secondary stroke reoccurrence, with sensitivity >90% and specificity >80%. However, in diagnostic settings, there is still a need to address the encountered analytical problems, particularly assay specificity and set up. In this study, a novel approach for NT-proBNP detection is demonstrated using an electrochemical immunoassay method. A label-free impedimetry immunosensor for stroke biomarker was developed using modified disposable screen-printed gold electrodes (SPGE) hosting specific anti-NT-proBNP capture antibody. The performance of our immunosensor was studied in the presence of NT-proBNP in both buffered and mock (porcine) plasma samples. A linear relation between the relative total resistance (ΔRtot) responses and the NT-proBNP concentrations in buffer was observed in a range from 0.1 to 5 ng mL-1 with a correlation coefficient (R2) of 0.94656. Overall, the biosensor has demonstrated the capability to quantitate NT-proBNP and differentiate such concentrations in a low concentration range, especially among 0, 0.1, 0.5, 1, and 3 ng mL-1 in plasma samples within 25 min. This range is valuable not only for classifying cardioembolic stroke (higher or equal to 0.5 ng mL-1), but also predicting the risk of secondary stroke reoccurrence (higher than 0.255 ng mL-1). Our biosensor has the potential to be used as an easy-to-use point-of-care test that is both accurate and affordable.

Application of emerging technologies to improve access to ischemic stroke care

During the past 20 years, the traditional supportive treatment for stroke has been radically transformed by advances in catheter technologies and a cohort of prominent randomized controlled trials that unequivocally demonstrated significant improvement in stroke outcomes with timely endovascular intervention. However, substantial limitations to treatment remain, among the most important being timely access to care. Nonetheless, stroke care has continued its evolution by incorporating technological advances from various fields that can further reduce patients' morbidity and mortality. In this paper the authors discuss the importance of emerging technologies—mobile stroke treatment units, telemedicine, and robotically assisted angiography—as future tools for expanding access to the diagnosis and treatment of acute ischemic stroke.

Recent advances in the management of acute ischemic stroke

In recent years, several landmark trials have transformed acute ischemic stroke care. The most dramatic results from the field of acute endovascular intervention demonstrate unequivocal benefit for a select group of patients with moderate to severe deficits presenting within 7 hours from onset and with occlusions of proximal arteries in the anterior circulation. In addition, technological advances and workflow efficiencies have facilitated more rapid delivery of acute stroke interventions. This review provides an overview of recent advances in the management of acute ischemic stroke.

Intravenous thrombolysis for ischemic stroke in the golden hour: propensity-matched analysis from the SITS-EAST registry

As there are scarce data regarding the outcomes of acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT) within 60 min from symptom onset ("golden hour"), we sought to compare outcomes between AIS patients treated within [GH(+)] and outside [GH(-)] the "golden hour" by analyzing propensity score matched data from the SITS-EAST registry. Clinical recovery (CR) at 2 and 24 h was defined as a reduction of ≥10 points on NIHSS-score or a total NIHSS-score of ≤3 at 2 and 24 h, respectively. A relative reduction in NIHSS-score of ≥40% at 2 h was considered predictive of complete recanalization (CREC). Symptomatic intracranial hemorrhage (sICH) was defined using SITS-MOST criteria. Favorable functional outcome (FFO) was defined as a mRS-score of 0-1 at 3 months. Out of 19,077 IVT-treated AIS patients, 71 GH(+) patients were matched to 6882 GH(-) patients, with no differences in baseline characteristics (p > 0.1). GH(+) had higher rates of CR at 2 (31.0 vs. 12.4%; p < 0.001) and 24 h (41 vs. 27%; p = 0.010), CREC at 2 h (39 vs. 21%; p < 0.001) and FFO (46.5 vs. 34.0%; p = 0.028) at 3 months. The rates of sICH and 3-month mortality did not differ (p > 0.2) between the two groups. GH(+) was associated with 2-h CR (OR: 5.34; 95% CI 2.53-11.03) and CREC (OR: 2.38; 95% CI 1.38-4.09), 24-h CR (OR: 1.88; 95% CI 1.08-3.26) and 3-month FFO (OR: 2.02; 95% CI 1.15-3.54) in multivariable logistic regression models adjusting for potential confounders. In conclusion, AIS treated with IVT within the GH seems to have substantially higher odds of early neurological recovery, CREC, 3-month FFO and functional improvement.

Mobile stroke units for prehospital thrombolysis, triage, and beyond: benefits and challenges

In acute stroke management, time is brain. Bringing swift treatment to the patient, instead of the conventional approach of awaiting the patient's arrival at the hospital for treatment, is a potential strategy to improve clinical outcomes after stroke. This strategy is based on the use of an ambulance (mobile stroke unit) equipped with an imaging system, a point-of-care laboratory, a telemedicine connection to the hospital, and appropriate medication. Studies of prehospital stroke treatment consistently report a reduction in delays before thrombolysis and cause-based triage in regard to the appropriate target hospital (eg, primary vs comprehensive stroke centre). Moreover, novel medical options for the treatment of stroke patients are also under investigation, such as prehospital differential blood pressure management, reversal of warfarin effects in haemorrhagic stroke, and management of cerebral emergencies other than stroke. However, crucial concerns regarding safety, clinical efficacy, best setting, and cost-effectiveness remain to be addressed in further studies. In the future, mobile stroke units might allow the investigation of novel diagnostic (eg, biomarkers and automated imaging evaluation) and therapeutic (eg, neuroprotective drugs and treatments for haemorrhagic stroke) options in the prehospital setting, thus functioning as a tool for research on prehospital stroke management.

Telemedicine Can Replace the Neurologist on a Mobile Stroke Unit

BACKGROUND AND PURPOSE

The BEST-MSU study (Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit) is a comparative effectiveness trial in patients randomized to mobile stroke unit or standard management. A substudy tested interrater agreement for tissue-type plasminogen activator eligibility between a telemedicine vascular neurologist and onboard vascular neurologist.

METHODS

On scene, both the telemedicine vascular neurologist and onboard vascular neurologist independently evaluated the patient, documenting their tissue-type plasminogen activator treatment decision, National Institutes of Health Stroke Scale score, and computed tomographic interpretation. Agreement was determined using Cohen κ statistic. Telemedicine-related technical failures that impeded remote assessment were recorded.

RESULTS

Simultaneous and independent telemedicine vascular neurologist and onboard vascular neurologist assessment was attempted in 174 patients. In 4 patients (2%), the telemedicine vascular neurologist could not make a decision because of technical problems. The telemedicine vascular neurologist agreed with the onboard vascular neurologist on 88% of evaluations (κ=0.73).

CONCLUSIONS

Remote telemedicine vascular neurologist assessment is reliable and accurate, supporting either telemedicine vascular neurologist or onboard vascular neurologist assessment on our mobile stroke unit.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02190500.

[Mobile stroke unit for prehospital stroke treatment]

CLINICAL ISSUE AND DIAGNOSTIC STANDARDS

The management of acute stroke patients suffers from several major problems in the daily clinical routine. In order to achieve optimal treatment a complex diagnostic work-up and rapid initiation of therapy are necessary; however, most patients arrive at hospital too late for any type of acute stroke treatment, although all forms of treatment are highly time-dependent according to the generally accepted "time is brain" concept.

DIAGNOSTIC INNOVATIONS

Recently, two randomized clinical trials demonstrated the feasibility of prehospital stroke diagnostic work-up and treatment. This was accomplished by use of a specialized ambulance, equipped with computed tomography for multimodal imaging and a point-of-care laboratory system.

PERFORMANCE

In both trials the results demonstrated a clear superiority of the prehospital treatment group with a significant reduction of treatment times, significantly increased number of patients treated within the first 60 min after symptom onset and an optimized triage to the correct target hospital.

ACHIEVEMENTS AND PRACTICAL RECOMMENDATIONS

Currently, mobile stroke units are in operation in various countries and should lead to an improvement in stroke treatment; nevertheless, intensive research is still needed to analyze the best framework settings for prehospital stroke management.

Telemedicine Quality and Outcomes in Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

Telestroke is one of the most frequently used and rapidly expanding applications of telemedicine, delivering much-needed stroke expertise to hospitals and patients. This document reviews the current status of telestroke and suggests measures for ongoing quality and outcome monitoring to improve performance and to enhance delivery of care.

METHODS

A literature search was undertaken to examine the current status of telestroke and relevant quality indicators. The members of the writing committee contributed to the review of specific quality and outcome measures with specific suggestions for metrics in telestroke networks. The drafts were circulated and revised by all committee members, and suggestions were discussed for consensus.

RESULTS

Models of telestroke and the role of telestroke in stroke systems of care are reviewed. A brief description of the science of quality monitoring and prior experience in quality measures for stroke is provided. Process measures, outcomes, tissue-type plasminogen activator use, patient and provider satisfaction, and telestroke technology are reviewed, and suggestions are provided for quality metrics. Additional topics include licensing, credentialing, training, and documentation.

In-Transit Telemedicine Speeds Ischemic Stroke Treatment

Background and Purpose—

Time to treatment is critically important in ischemic stroke. We compared the efficacy and cost of teleneurology evaluation during patient transport with that of mobile stroke transport units.

Methods—

Using cellular-connected telemedicine devices, we assessed 89 presumptive stroke patients in ambulances in transit. Paramedics assisted remote teleneurologists in obtaining a simplified history and examination, then coordinating care with the receiving emergency department. We prospectively assessed door-to-needle and last-known-well-to-needle times for all intravenous alteplase–treated stroke patients brought to our emergency departments by emergency medical services’ transport, comparing those with and without in-transit telestroke.

Results—

From January 2015 through March 2016, 111 stroke patients received intravenous alteplase at study emergency departments. Mean door to needle was 13 minutes less with in-transit telestroke (28 versus 41; P =0.02). Although limitations in cellular communication degraded transmission quality, this did not prevent the completion of satisfactory patient evaluations.

Conclusions—

Improvement in time to treat seems comparable with in-transit telestroke and mobile stroke transport units. The low cost/unit makes this approach scalable, potentially providing rapid management of more patients.

First Automated Stroke Imaging Evaluation via Electronic Alberta Stroke Program Early CT Score in a Mobile Stroke Unit

Background: Recently, a mobile stroke unit (MSU) was shown to facilitate acute stroke treatment directly at the emergency site. The neuroradiological expertise of the MSU is improved by its ability to detect early ischemic damage via automatic electronic (e) evaluation of CT scans using a novel software program that calculates the electronic Alberta Stroke Program Early CT Score (e-ASPECTS). Methods: The feasibility of integrating e-ASPECTS into an ambulance was examined, and the clinical integration and utility of the software in 15 consecutive cases evaluated. Results: Implementation of e-ASPECTS onto the MSU and into the prehospital stroke management was feasible. The values of e-ASPECTS matched with the results of conventional neuroradiologic analysis by the MSU team. The potential benefits of e-ASPECTS were illustrated by three cases. In case 1, excluding early infarct signs supported the decision to directly perform prehospital thrombolysis. In case 2, in which stroke was caused by large-vessel occlusion, the high e-ASPECTS value supported the decision to initiate intra-arterial treatment and triage the patient to a comprehensive stroke center. In case 3, the e-ASPECTS value was 10, indicating the absence of early infarct signs despite pre-existing cerebral microangiopathy and macroangiopathy, a finding indicating the program's robustness against artefacts. Conclusions: This study on the integration of e-ASPECTS into the prehospital stroke management via a MSU showed for the first time that such integration is feasible, and aids both decision regarding the treatment option and the triage regarding the most appropriate target hospital.

Prehospital Imaging-Based Triage of Head Trauma with a Mobile Stroke Unit: First Evidence and Literature Review

BACKGROUND

An ambulance equipped with a computed tomography (CT) scanner, point-of-care laboratory, and telemedicine capabilities (Mobile Stroke Unit [MSU]) has been shown to enable delivery of thrombolysis to stroke patients at the emergency site, thereby significantly decreasing time to treatment. However, the MSU frequently assesses patients with cerebral disorders other than stroke. For some of these disorders, prehospital CT scanning may also be beneficial.

METHODS

Our institution manages a program investigating prehospital stroke treatment of patients with neurological emergencies. We assessed a patient with head trauma for whom prehospital CT scanning and laboratory tests allowed cause-based triage to the most appropriate hospital. We examined implications of this case for clinical practice in light of a literature review.

RESULTS

The MSU was dispatched to assess a 74-year-old woman with suspected head trauma or stroke, found lying on the floor with a left frontal laceration. Her Glasgow Coma Scale score was 13, apart from drowsiness she exhibited no neurologic deficit. A CT scan ruled out intracranial hemorrhage and skull fracture. On the basis of these prehospital diagnostic findings, the patient was taken to the nearest primary care hospital rather than to a trauma center with neurosurgery facilities.

CONCLUSION

Patients with neurologic disorders other than stroke, such as traumatic brain injury, may also benefit from prehospital CT studies. This case report and the results of our analysis of the literature support the potential benefit of prehospital imaging in correctly triaging patients with suspected traumatic brain injury to the appropriate target hospital.

Prehospital stroke care: telemedicine, thrombolysis and neuroprotection

Over the last 15 years, new approaches regarding neuroprotective and thrombolytic strategies in stroke management have been evaluated in the prehospital setting. These efforts have provided exciting new potentials of hyperacute stroke care. Trials have shown that the use of specialized stroke ambulances increases the proportion of patients receiving intravenous thrombolysis and shortens alarm-to-treatment time by approximately half an hour compared to standard care. Intravenous thrombolysis within the ultra-early time window of the 'golden hour' has become a realistic scenario. However, direct effects of prehospital stroke care on functional outcome have yet to be shown and other approaches such as neuroprotective treatments could not demonstrate clinical benefit so far. There is a clear need for systematic research in the prehospital field to test the clinical effectiveness and cost-effectiveness of new therapeutic strategies. It will be necessary to test various components of prehospital stroke care alone and in combination.

Telestroke—the promise and the challenge. Part two—expansion and horizons

Acute ischemic stroke remains a major public health concern, with low national treatment rates for the condition, demonstrating a disconnection between the evidence of treatment benefit and delivery of this treatment. Intravenous thrombolysis and endovascular thrombectomy are both strongly evidence supported and exquisitely time sensitive therapies. The mismatch between the distribution and incidence of stroke presentations and the availability of specialist care significantly affects access to care. Telestroke, the use of telemedicine for stroke, aims to surmount this hurdle by distributing stroke expertise more effectively, through video consultation with and examination of patients in locations removed from specialist care. This is the second of a two part review, and is focused on the challenges telestroke faces for wider adoption. It further details the anticipated evolution of this novel therapeutic platform, and the potential roles it holds in stroke prevention, ambulance based care, rehabilitation, and research.

The Evolution of Mechanical Thrombectomy for Acute Stroke

OPINION STATEMENT

The natural history of an acute ischemic stroke from a large vessel occlusion (LVO) is poor and has long challenged stroke therapy. Recently, endovascular therapy has demonstrated superiority to medical management in appropriately selected patients. This advance has revolutionized acute care for LVO and mandates a reevaluation of the entire chain of stroke care delivery, including patient selection, intervention, and post-procedural care. Since endovascular therapy is a therapy specifically targeting LVO, its application should be restricted to those patients only. Clinical and radiologic parameters need to be considered in patient selection. Data supports that all patients over the age of 18 years presenting with a National Institutes of Health Stroke Scale (NIHSS) of 6 or greater within 6 hours of symptom onset should be considered for emergent endovascular therapy. Radiologically, those with a LVO of the internal carotid artery (ICA) or middle cerebral artery (MCA) M1 portion, intermediate or good collaterals and without large established infarct should be considered endovascular candidates. Selection beyond these parameters remains an open question and is being actively evaluated. In all cases, revascularization should be attempted with a new generation device (stentriever or direct aspiration), as these techniques are most likely to deliver adequate reperfusion. Post-revascularization, patients are closely monitored in an intensive care setting followed by discharge to rehabilitation, if required, or directly home. Patients should be evaluated in delayed fashion to assess recovery (typically at 3 months post-treatment). Ultimately, the poor natural history of ischemic stroke from LVO and the potential significant benefit from endovascular therapy over medical management alone necessitate a national response to ensure we identify and treat all eligible patients as rapidly and effectively as possible.

Acute Stroke: Current Evidence-based Recommendations for Prehospital Care

Introduction

In the United States, emergency medical services (EMS) protocols vary widely across jurisdictions. We sought to develop evidence-based recommendations for the prehospital evaluation and treatment of a patient with a suspected stroke and to compare these recommendations against the current protocols used by the 33 EMS agencies in the state of California.

Methods

We performed a literature review of the current evidence in the prehospital treatment of a patient with a suspected stroke and augmented this review with guidelines from various national and international societies to create our evidence-based recommendations. We then compared the stroke protocols of each of the 33 EMS agencies for consistency with these recommendations. The specific protocol components that we analyzed were the use of a stroke scale, blood glucose evaluation, use of supplemental oxygen, patient positioning, 12-lead electrocardiogram (ECG) and cardiac monitoring, fluid assessment and intravenous access, and stroke regionalization.

Results

Protocols across EMS agencies in California varied widely. Most used some sort of stroke scale with the majority using the Cincinnati Prehospital Stroke Scale (CPSS). All recommended the evaluation of blood glucose with the level for action ranging from 60 to 80mg/dL. Cardiac monitoring was recommended in 58% and 33% recommended an ECG. More than half required the direct transport to a primary stroke center and 88% recommended hospital notification.

Conclusion

Protocols for a patient with a suspected stroke vary widely across the state of California. The evidence-based recommendations that we present for the prehospital diagnosis and treatment of this condition may be useful for EMS medical directors tasked with creating and revising these protocols.

Comparison of outcomes of patients with inpatient or outpatient onset ischemic stroke

BACKGROUND

Reperfusion times for ischemic stroke occurring in the outpatient setting have improved significantly in recent years. However, quality improvement efforts have largely ignored ischemic stroke occurring in patients hospitalized for unrelated indications.

METHODS

We performed a cohort study involving patients with ischemic stroke (with inpatient or outpatient onset) from 2009 to 2013 who were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. A propensity score-adjusted regression analysis was used to assess the association of location of onset and outcomes. Mixed effects methods were employed to control for clustering at the hospital level.

RESULTS

Of the 176 571 ischemic strokes, 160 157 (90.7%) occurred outside of a hospital and 16 414 (9.3%) occurred in patients hospitalized for unrelated indications. Using a logistic regression model with propensity score adjustment, we demonstrated that inpatient stroke onset was associated with increased inpatient mortality (OR 3.09; 95% CI 2.81 to 3.38), rate of discharge to rehabilitation (OR 2.57; 95% CI 2.37 to 2.79), and length of stay (LOS) (β=11.58; 95% CI 10.73 to 12.42). In addition, it was associated with lower odds (OR 0.69; 95% CI 0.62 to 0.77) of undergoing stroke-related interventions (mechanical thrombectomy and intravenous tissue plasminogen activator) compared with outpatient stroke onset.

CONCLUSIONS

Using a comprehensive all-payer cohort of patients with ischemic stroke in New York State, we identified an association of inpatient stroke onset with fewer stroke-related interventions and increased mortality, rate of discharge to rehabilitation, and LOS.

Brain Imaging Using Mobile CT: Current Status and Future Prospects

Computed tomography (CT) is an invaluable tool in the diagnosis of many clinical conditions. Several advancements in biomedical engineering have achieved increase in speed, improvements in low-contrast detectability and image quality, and lower radiation. Portable or mobile CT constituted one such important advancement. It is especially useful in evaluating critically ill, intensive care unit patients by scanning them at bedside. A paradigm shift in utilization of mobile CT was its installation in ambulances for the management of acute stroke. Given the time sensitive nature of acute ischemic stroke, Mobile stroke units (MSU) were developed in Germany consisting of an ambulance equipped with a CT scanner, point of care laboratory system, along with teleradiological support. In a radical reconfiguration of stroke care, the MSU would bring the CT scanner to the stroke patient, without waiting for the patient at the emergency room. Two separate MSU projects in Saarland and Berlin demonstrated the safety and feasibility of this concept for prehospital stroke care, showing increased rate of intravenous thrombolysis and significant reduction in time to treatment compared to conventional care. MSU also improved the triage of patients to appropriate and specialized hospitals. Although multiple issues remain yet unanswered with the MSU concept including clinical outcome and cost-effectiveness, the MSU venture is visionary and enables delivery of life-saving and enhancing treatment for ischemic and hemorrhagic stroke. In this review, we discuss the development of mobile CT and its applications, with specific focus on its use in MSUs along with our institution's MSU experience.

Benefits of Stroke Treatment Using a Mobile Stroke Unit Compared With Standard Management: The BEST-MSU Study Run-In Phase

BACKGROUND AND PURPOSE

Faster treatment with intravenous tissue-type plasminogen activator (tPA) is likely to improve outcomes. Optimizing prehospital triage by mobile stroke units (MSUs) may speed treatment times. The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) study was launched in May 2014 using the first MSU in the United States to compare stroke management using an MSU versus standard management (SM). Herein, we describe the results of the prespecified, nonrandomized run-in phase designed to obtain preliminary data on study logistics.

METHODS

The run-in phase consisted of 8 MSU weeks when all-patient care occurred on the MSU and 2 SM weeks when the MSU nurse met personnel on scene or at the emergency department to ensure comparability with MSU patients. Telemedicine was independently performed in 9 MSU cases.

RESULTS

Of 130 alerts, 24 MSU and 2 SM patients were enrolled. Twelve of 24 MSU patients received tPA on board; 4 were treated within 60 minutes of last seen normal, and 4 went on to endovascular treatment. There were no hemorrhagic complications. Four had primary intracerebral hemorrhage. Agreement on tPA eligibility between the onsite and telemedicine physician was 90%.

CONCLUSIONS

The run-in phase provided a tPA treatment rate of 1.5 patients per week, assured us that treatment within 60 minutes of onset is possible, and enabled enrollment of patients on SM weeks. We also recognized the opportunity to assess the effect of the MSU on endovascular treatment and intracerebral hemorrhage. Challenges include the need to control biased patient selection on MSU versus SM weeks and establish inter-rater agreement for tPA treatment using telemedicine.