Diagnosis, Workup, Risk Reduction of Transient Ischemic Attack in the Emergency Department Setting: A Scientific Statement From the American Heart Association.

At least 240 000 individuals experience a transient ischemic attack each year in the United States. Transient ischemic attack is a strong predictor of subsequent stroke. The 90-day stroke risk after transient ischemic attack can be as high as 17.8%, with almost half occurring within 2 days of the index event. Diagnosing transient ischemic attack can also be challenging given the transitory nature of symptoms, often reassuring neurological examination at the time of evaluation, and lack of confirmatory testing. Limited resources, such as imaging availability and access to specialists, can further exacerbate this challenge. This scientific statement focuses on the correct clinical diagnosis, risk assessment, and management decisions of patients with suspected transient ischemic attack. Identification of high-risk patients can be achieved through use of comprehensive protocols incorporating acute phase imaging of both the brain and cerebral vasculature, thoughtful use of risk stratification scales, and ancillary testing with the ultimate goal of determining who can be safely discharged home from the emergency department versus admitted to the hospital. We discuss various methods for rapid yet comprehensive evaluations, keeping resource-limited sites in mind. In addition, we discuss strategies for secondary prevention of future cerebrovascular events using maximal medical therapy and patient education.

Travel time and distance for bypass and non-bypass routing of stroke patients in the USA.

BACKGROUND: Endovascular thrombectomy is not available at all hospitals that offer intravenous thrombolysis, prompting debate regarding the preferred transport destination for acute ischemic stroke. This study aimed to quantify real-world travel time and distance of bypass and non-bypass transport models for large-vessel occlusion (LVO) and non-LVO stroke. METHODS: This cross-sectional study included population data of census tracts in the contiguous USA from the 2014-2018 United States Census Bureau's American Community Survey, stroke (thrombolysis-capable) and thrombectomy-capable centers certified by a state or national body, and road network data from a mapping service. Census tracts were categorized by urbanization level. Data were retrieved from March to November 2020. Travel times and distances were calculated for each census tract to each of the following: nearest stroke center (nearest), nearest thrombectomy-capable center (bypass), and nearest stroke center then to the nearest thrombectomy-capable center (transfer). Population-weighted median and IQR were calculated nationally and by urbanization. RESULTS: 72 538 census tracts, 2388 stroke hospitals, and 371 thrombectomy-capable centers were included. Nationally, population-weighted median travel time for nearest and bypass routing was 11.7 min (IQR 7.7-19.3) and 26.4 min (14.8-55.1), respectively. For transfer routing, the population-weighted median travel times with 60 min, 90 min, and 120 min door-in-door-out times were 94.1 min (78.5-127.7), 124.1 min (108.5-157.7), and 154.1 min (138.4-187.6), respectively. CONCLUSIONS: Bypass routing offers modest travel time benefits for LVO patients and incurs modest penalties for non-LVO patients. Differences are greatest in rural areas. A majority of Americans live in areas for which current guidelines recommend bypass.

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.

Maintaining Stroke Care During the COVID-19 Pandemic in Lower- and Middle-Income Countries: World Stroke Organization Position Statement Endorsed by American Stroke Association and American Heart Association.

For more than a year, the SARS-CoV-2 pandemic has had a devastating effect on global health. High-, low, and middle-income countries are struggling to cope with the spread of newer mutant strains of the virus. Delivery of acute stroke care remains a priority despite the pandemic. In order to maintain the time-dependent processes required to optimize delivery of intravenous thrombolysis and endovascular therapy, most countries have reorganized infrastructure to optimize human resources and critical services. Low-and-middle income countries (LMIC) have strained medical resources at baseline and often face challenges in the delivery of stroke systems of care (SSOC). This position statement aims to produce pragmatic recommendations on methods to preserve the existing SSOC during COVID-19 in LMIC and propose best stroke practices that may be low cost but high impact and commonly shared across the world.

Maintaining stroke care during the COVID-19 pandemic in lower- and middle-income countries: World Stroke Organization Position Statement endorsed by American Stroke Association and American Heart Association.

For more than a year, the SARS-CoV-2 pandemic has had a devastating effect on global health. High-, low-, and middle-income countries are struggling to cope with the spread of newer mutant strains of the virus. Delivery of acute stroke care remains a priority despite the pandemic. In order to maintain the time-dependent processes required to optimize delivery of intravenous thrombolysis and endovascular therapy, most countries have reorganized infrastructure to optimize human resources and critical services. Low-and-middle income countries (LMIC) have strained medical resources at baseline and often face challenges in the delivery of stroke systems of care (SSOC). This position statement aims to produce pragmatic recommendations on methods to preserve the existing SSOC during COVID-19 in LMIC and propose best stroke practices that may be low cost but high impact and commonly shared across the world.

Demographic Disparities in Proximity to Certified Stroke Care in the United States.

Background and Purpose: Demographic disparities in proximity to stroke care influence time to treatment and clinical outcome but remain understudied at the national level. This study quantifies the relationship between distance to the nearest certified stroke hospital and census-derived demographics. Methods: This cross-sectional study included population data by census tract from the United States Census Bureau's 2014­2018 American Community Survey, stroke hospitals certified by a state or national body and providing intravenous thrombolysis, and geographic data from a public mapping service. Data were retrieved from March to November 2020. Quantile regression analysis was used to compare relationships between road distance to the nearest stroke center for each census tract and tract-level demographics of age, race, ethnicity, medical insurance status, median annual income, and population density. Results: Two thousand three hundred eighty-eight stroke centers and 71 929 census tracts including 316 995 649 individuals were included. Forty-nine thousand nine hundred eighteen (69%) tracts were urban. Demographic disparities in proximity to certified stroke care were greater in nonurban areas than urban areas. Higher representation of individuals with age ≥65 years was associated with increased median distance to a certified stroke center in nonurban areas (0.51 km per 1% increase [99.9% CI, 0.42­0.59]) but not in urban areas (0.00 km [−0.01 to 0.01]). In urban and nonurban tracts, median distance was greater with higher representation of American Indian (urban: 0.10 km per 1% increase [0.06­0.14]; nonurban: 1.06 km [0.98­1.13]) or uninsured populations (0.02 km [0.00­0.03]; 0.27 km [0.15­0.38]). Each $10 000 increase in median income was associated with a decrease in median distance of 5.04 km [4.31­5.78] in nonurban tracts, and an increase of 0.17 km [0.10­0.23] in urban tracts. Conclusions: Disparities were greater in nonurban areas than in urban areas. Nonurban census tracts with greater representation of elderly, American Indian, or uninsured people, or low median income were substantially more distant from certified stroke care.

Pandemic Guidance for Stroke Centers Aiding COVID-19 Treatment Teams.

The coronavirus disease 2019 (COVID-19) pandemic has in some regions overwhelmed the capacity and staffing needs of healthcare systems, necessitating the provision of resources and staff from different disciplines to aid COVID treatment teams. Stroke centers have multidisciplinary clinical and procedural expertise to support COVID treatment teams. Staff safety and patient safety are essential, as are open lines of communication between stroke center leaders and hospital leadership in a pandemic where policies and procedures can change or evolve rapidly. Support needs to be allocated in a way that allows for the continued operation of a fully capable stroke center, with the ability to adjust if stroke center volume or staff attrition requires.

Prehospital Triage of Acute Stroke Patients During the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has broad implications on stroke patient triage. Emergency medical services providers have to ensure timely transfer of patients while minimizing the risk of infectious exposure for themselves, their co-workers, and other patients. This statement paper provides a conceptual framework for acute stroke patient triage and transfer during the COVID-19 pandemic and similar healthcare emergencies in the future.

Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department With Acute Headache

This clinical policy from the American College of Emergency Physicians addressed key issues in the evaluation and management of adult patients presenting to the emergency department with acute headache. A writing subcommittee conducted a systematic review of the literature to derive evidence-based recommendations to answer the following clinical questions: (1) In the adult emergency department patient presenting with acute headache, are there risk-stratification strategies that reliably identify the need for emergent neuroimaging? (2) In the adult emergency department patient treated for acute primary headache, are nonopioids preferred to opioid medications? (3) In the adult emergency department patient presenting with acute headache, does a normal noncontrast head computed tomography scan performed within 6 hours of headache onset preclude the need for further diagnostic workup for subarachnoid hemorrhage? (4) In the adult emergency department patient who is still considered to be at risk for subarachnoid hemorrhage after a negative noncontrast head computed tomography, is computed tomography angiography of the head as effective as lumbar puncture to safely rule out subarachnoid hemorrhage? Evidence was graded and recommendations were made based on the strength of the available data.

Effect of Recombinant Activated Coagulation Factor VII on Hemorrhage Expansion Among Patients With Spot Sign-Positive Acute Intracerebral Hemorrhage: The SPOTLIGHT and STOP-IT Randomized Clinical Trials.

Importance: Intracerebral hemorrhage (ICH) is a devastating stroke type that lacks effective treatments. An imaging biomarker of ICH expansion-the computed tomography (CT) angiography spot sign-may identify a subgroup that could benefit from hemostatic therapy. Objective: To investigate whether recombinant activated coagulation factor VII (rFVIIa) reduces hemorrhage expansion among patients with spot sign-positive ICH. Design, Setting, and Participants: In parallel investigator-initiated, multicenter, double-blind, placebo-controlled randomized clinical trials in Canada ("Spot Sign" Selection of Intracerebral Hemorrhage to Guide Hemostatic Therapy [SPOTLIGHT]) and the United States (The Spot Sign for Predicting and Treating ICH Growth Study [STOP-IT]) with harmonized protocols and a preplanned individual patient-level pooled analysis, patients presenting to the emergency department with an acute primary spontaneous ICH and a spot sign on CT angiography were recruited. Data were collected from November 2010 to May 2016. Data were analyzed from November 2016 to May 2017. Interventions: Eligible patients were randomly assigned 80 µg/kg of intravenous rFVIIa or placebo as soon as possible within 6.5 hours of stroke onset. Main Outcomes and Measures: Head CT at 24 hours assessed parenchymal ICH volume expansion from baseline (primary outcome) and total (ie, parenchymal plus intraventricular) hemorrhage volume expansion (secondary outcome). The pooled analysis compared hemorrhage expansion between groups by analyzing 24-hour volumes in a linear regression model adjusted for baseline volumes, time from stroke onset to treatment, and trial. Results: Of the 69 included patients, 35 (51%) were male, and the median (interquartile range [IQR]) age was 70 (59-80) years. Baseline median (IQR) ICH volumes were 16.3 (9.6-39.2) mL in the rFVIIa group and 20.4 (8.6-32.6) mL in the placebo group. Median (IQR) time from CT to treatment was 71 (57-96) minutes, and the median (IQR) time from stroke onset to treatment was 178 (138-197) minutes. The median (IQR) increase in ICH volume from baseline to 24 hours was small in both the rFVIIa group (2.5 [0-10.2] mL) and placebo group (2.6 [0-6.6] mL). After adjustment, there was no difference between groups on measures of ICH or total hemorrhage expansion. At 90 days, 9 of 30 patients in the rFVIIa group and 13 of 34 in the placebo group had died or were severely disabled (P = .60). Conclusions and Relevance: Among patients with spot sign-positive ICH treated a median of about 3 hours from stroke onset, rFVIIa did not significantly improve radiographic or clinical outcomes. Trial Registration: ClinicalTrials.gov identifier: NCT01359202 and NCT00810888.

Recommendations for the Establishment of Stroke Systems of Care: A 2019 Update.

In 2005, the American Stroke Association published recommendations for the establishment of stroke systems of care and in 2013 expanded on them with a statement on interactions within stroke systems of care. The aim of this policy statement is to provide a comprehensive review of the scientific evidence evaluating stroke systems of care to date and to update the American Stroke Association recommendations on the basis of improvements in stroke systems of care. Over the past decade, stroke systems of care have seen vast improvements in endovascular therapy, neurocritical care, and stroke center certification, in addition to the advent of innovations, such as telestroke and mobile stroke units, in the context of significant changes in the organization of healthcare policy in the United States. This statement provides an update to prior publications to help guide policymakers and public healthcare agencies in continually updating their stroke systems of care in light of these changes. This statement and its recommendations span primordial and primary prevention, acute stroke recognition and activation of emergency medical services, triage to appropriate facilities, designation of and treatment at stroke centers, secondary prevention at hospital discharge, and rehabilitation and recovery.

To Treat or Not to Treat?

Background and Purpose- The 2015 updated US Food and Drug Administration alteplase package insert altered several contraindications. We thus explored clinical factors influencing alteplase treatment decisions for patients with minor stroke. Methods- An expert panel selected 7 factors to build a series of survey vignettes: National Institutes of Health Stroke Scale (NIHSS), NIHSS area of primary deficit, baseline functional status, previous ischemic stroke, previous intracerebral hemorrhage, recent anticoagulation, and temporal pattern of symptoms in first hour of care. We used a fractional factorial design (150 vignettes) to provide unconfounded estimates of the effect of all 7 main factors, plus first-order interactions for NIHSS. Surveys were emailed to national organizations of neurologists, emergency physicians, and colleagues. Physicians were randomized to 1 of 10 sets of 15 vignettes, presented randomly. Physicians reported the subjective likelihood of giving alteplase on a 0 to 5 scale; scale categories were anchored to 6 probabilities from 0% to 100%. A conjoint statistical analysis was applied. Results- Responses from 194 US physicians yielded 156 with complete vignette data: 74% male, mean age 46, 80% neurologists. Treatment mean probabilities for individual vignettes ranged from 6% to 95%. Treatment probability increased from 24% for NIHSS score =1 to 41% for NIHSS score =5. The conjoint model accounted for 25% of total observed response variance. In contrast, a model accounting for all possible interactions accounted for 30% variance. Four of the 7 factors accounted jointly for 58% of total relative importance within the conjoint model: previous intracerebral hemorrhage (18%), recent anticoagulation (17%), NIHSS (13%), and previous ischemic stroke (10%). Conclusions- Four main variables jointly account for only a small fraction (<15%) of the total variance related to deciding to treat with intravenous alteplase, reflecting high variability and complexity. Future studies should consider other variables, including physician characteristics.

Streamlined triage and transfer protocols improve door-to-puncture time for endovascular thrombectomy in acute ischemic stroke.

OBJECTIVE: Shorter time from symptom onset to treatment is associated with improved outcomes in patients who undergo mechanical thrombectomy for treatment of acute ischemic stroke due to emergent large vessel occlusion. In this work, we detail pre-thrombectomy process improvements in a multi-hospital network and report the effect on door-to-puncture time in patients undergoing mechanical thrombectomy. PATIENTS AND METHODS: A streamlined workflow was adopted to minimize door-to-puncture time. Key features of this workflow included rapid and concurrent clinical and radiological evaluation with point-of-care image interpretation, pre-transfer IV thrombolysis and CTA for transferred patients, immediate transport to the angiography suite potentially before neurointerventional radiology team arrival, and minimalist room setup. Door-to-puncture time was measured prospectively and analyzed retrospectively for 78 consecutive patients treated between January 2015 and December 2015. Statistical analysis was performed using the F-test on individual coefficients of a linear regression model. RESULTS: From quarter 1 to quarter 4, the number of thrombectomies performed increased by 173% (11 patients to 30 patients, p = 0.002), and there was a significant increase in the proportion of transferred patients that underwent pre-transfer CTA (p = 0.04). During this interval, overall median door-to-puncture time decreased by 74% (147 min to 39 min, p < 0.001); this decrease was greatest in transferred patients with pre-transfer CTA (81% decrease, 129 min to 25 min, p < 0.001) and smallest in patients presenting directly to the emergency department (52% decrease, 167 min to 87 min, p < 0.001). CONCLUSION: Simple workflow improvements to streamline in-hospital triage and perform critical workup at transferring hospitals can produce reductions in door-to-puncture time.

The Advanced Reperfusion Era: Implications for Emergency Systems of Ischemic Stroke Care.

Large vessel ischemic stroke is a leading cause of morbidity and mortality throughout the world. Recent advances in endovascular stroke treatment are changing the treatment paradigm for these patients. This concepts article summarizes the time-dependent nature of stroke care and evaluates the recent advancements in endovascular treatment. These advancements have significant implications for out-of-hospital, hospital, and regional systems of stroke care. Emergency medicine clinicians have a central role in implementing these systems that will ensure timely treatment of patients and selection of those who may benefit from endovascular care.

Streamlined Hyperacute Magnetic Resonance Imaging Protocol Identifies Tissue-Type Plasminogen Activator-Eligible Stroke Patients When Clinical Impression Is Stroke Mimic.

BACKGROUND AND PURPOSE: Stroke mimics (SM) challenge the initial assessment of patients presenting with possible acute ischemic stroke (AIS). When SM is considered likely, intravenous tissue-type plasminogen activator (tPA) may be withheld, risking an opportunity to treat AIS. Although computed tomography is routinely used for tPA decision making, magnetic resonance imaging (MRI) may diagnose AIS when SM is favored but not certain. We hypothesized that a hyperacute MRI (hMRI) protocol would identify tPA-eligible AIS patients among those initially favored to have SM. METHODS: A streamlined hMRI protocol was designed based on barriers to rapid patient transport, MRI acquisition, and post-MRI tPA delivery. Neurologists were trained to order hMRI when SM was favored and tPA was being withheld. The use of hMRI for tPA decision making, door-to-needle times, and outcomes were compared before hMRI implementation (pre-hMRI: August 1, 2011 to July 31, 2013) and after (post-hMRI, August 1, 2013, to January 15, 2015). RESULTS: Post hMRI, 57 patients with suspected SM underwent hMRI (median MRI-order-to-start time, 29 minutes), of whom, 11 (19%) were diagnosed with AIS and 7 (12%) received tPA. Pre-hMRI, no tPA-treated patients were screened with hMRI. Post hMRI, 7 of 106 (6.6%) tPA-treated patients underwent hMRI to aid in decision making because of suspected SM (0% versus 6.6%; P=0.001). To ensure standard care was maintained after implementing the hMRI protocol, pre- versus post-hMRI tPA-treated cohorts were compared and did not differ: door-to-needle time (39 versus 37 minutes; P=0.63), symptomatic hemorrhage rate (4.5% versus 1.9%; P=0.32), and favorable discharge location (85% versus 89%; P=0.37). CONCLUSIONS: A streamlined hMRI protocol permitted tPA administration to a small, but significant, subset of AIS patients initially considered to have SM.

Defining the ischemic penumbra using magnetic resonance oxygen metabolic index.

BACKGROUND AND PURPOSE: Penumbral biomarkers promise to individualize treatment windows in acute ischemic stroke. We used a novel magnetic resonance imaging approach that measures oxygen metabolic index (OMI), a parameter closely related to positron emission tomography-derived cerebral metabolic rate of oxygen utilization (CMRO2), to derive a pair of ischemic thresholds: (1) an irreversible-injury threshold that differentiates ischemic core from penumbra and (2) a reversible-injury threshold that differentiates penumbra from tissue not-at-risk for infarction. METHODS: Forty patients with acute ischemic stroke underwent magnetic resonance imaging at 3 time points after stroke onset: <4.5 hours (for OMI threshold derivation), 6 hours (to determine reperfusion status), and 1 month (for infarct probability determination). A dynamic susceptibility contrast method measured cerebral blood flow, and an asymmetrical spin echo sequence measured oxygen extraction fraction, to derive OMI (OMI=cerebral blood flow×oxygen extraction fraction). Putative ischemic threshold pairs were iteratively tested using a computation-intensive method to derive infarct probabilities in 3 tissue groups defined by the thresholds (core, penumbra, and not-at-risk tissue). An optimal threshold pair was chosen based on its ability to predict infarction in the core, reperfusion-dependent survival in the penumbra, and survival in not-at-risk tissue. The predictive abilities of the thresholds were then tested within the same cohort using a 10-fold cross-validation method. RESULTS: The optimal OMI ischemic thresholds were found to be 0.28 and 0.42 of normal values in the contralateral hemisphere. Using the 10-fold cross-validation method, median infarct probabilities were 90.6% for core, 89.7% for nonreperfused penumbra, 9.95% for reperfused penumbra, and 6.28% for not-at-risk tissue. CONCLUSIONS: OMI thresholds, derived using voxel-based, reperfusion-dependent infarct probabilities, delineated the ischemic penumbra with high predictive ability. These thresholds will require confirmation in an independent patient sample.