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

GPT-4 as a Clinical Decision Support Tool in Ischemic Stroke Management: Evaluation Study

BACKGROUND

Cerebrovascular diseases are the second most common cause of death worldwide and one of the major causes of disability burden. Advancements in artificial intelligence have the potential to revolutionize health care delivery, particularly in critical decision-making scenarios such as ischemic stroke management.

OBJECTIVE

This study aims to evaluate the effectiveness of GPT-4 in providing clinical support for emergency department neurologists by comparing its recommendations with expert opinions and real-world outcomes in acute ischemic stroke management.

METHODS

A cohort of 100 patients with acute stroke symptoms was retrospectively reviewed. Data used for decision-making included patients' history, clinical evaluation, imaging study results, and other relevant details. Each case was independently presented to GPT-4, which provided scaled recommendations (1-7) regarding the appropriateness of treatment, the use of tissue plasminogen activator, and the need for endovascular thrombectomy. Additionally, GPT-4 estimated the 90-day mortality probability for each patient and elucidated its reasoning for each recommendation. The recommendations were then compared with a stroke specialist's opinion and actual treatment decisions.

RESULTS

In our cohort of 100 patients, treatment recommendations by GPT-4 showed strong agreement with expert opinion (area under the curve [AUC] 0.85, 95% CI 0.77-0.93) and real-world treatment decisions (AUC 0.80, 95% CI 0.69-0.91). GPT-4 showed near-perfect agreement with real-world decisions in recommending endovascular thrombectomy (AUC 0.94, 95% CI 0.89-0.98) and strong agreement for tissue plasminogen activator treatment (AUC 0.77, 95% CI 0.68-0.86). Notably, in some cases, GPT-4 recommended more aggressive treatment than human experts, with 11 instances where GPT-4 suggested tissue plasminogen activator use against expert opinion. For mortality prediction, GPT-4 accurately identified 10 (77%) out of 13 deaths within its top 25 high-risk predictions (AUC 0.89, 95% CI 0.8077-0.9739; hazard ratio 6.98, 95% CI 2.88-16.9; P<.001), outperforming supervised machine learning models such as PRACTICE (AUC 0.70; log-rank P=.02) and PREMISE (AUC 0.77; P=.07).

CONCLUSIONS

This study demonstrates the potential of GPT-4 as a viable clinical decision-support tool in the management of acute stroke. Its ability to provide explainable recommendations without requiring structured data input aligns well with the routine workflows of treating physicians. However, the tendency toward more aggressive treatment recommendations highlights the importance of human oversight in clinical decision-making. Future studies should focus on prospective validations and exploring the safe integration of such artificial intelligence tools into clinical practice.

Validation and safety of AmbuLatory care for transient ischemic attack from emergency department (VALID study)

BACKGROUND

Transient Ischemic Attacks (TIAs) are a common reason for Emergency Department (ED) visits and represent a significant public health issue. Patients experiencing TIAs often face significant delays in undergoing various tests due to ED overcrowding and limited availability of neurologists. Emergency physicians (EPs) and neurologists have identified several criteria for allowing outpatient management. We conducted this study to assess the safety of this approach.

METHODS

A reappointment pathway was established to oversee the management of TIAs following an ED visit. The primary objective was to evaluate the safety of this pathway by monitoring any events occurring between discharge from the ED and the neurology reappointment. We conducted a retrospective descriptive single-center study of patients who benefited from this pathway between September 2021 and September 2023. In the case of an event, we assessed sequalae using NIHSS and Modified Rankin Scale.

RESULTS

186 patients were included, with a mean age of 64 years. 53.7 % were women. The median ABCD2 score was 3. The median time spent in the ED was 444 min. Eight patients experienced an event. The risk of post-TIA event was 2.7 % at 30 days, and 3.2 % at 90 days. None of the patients had sequala at the end of the follow-up. 12.9 % of MRI scans revealed recent established strokes.

CONCLUSION

Our study demonstrates the safety of a systematic reappointment pathway for patients presenting with TIAs in the ED. Future research should validate our results with larger cohorts and explore strategies to optimize outpatient management of patients.

Secondary Risk Reduction after Transient Ischemic Attack and Minor Stroke

This article discusses the evolving definitions of transient ischemic attack and minor strokes, highlighting the shared risk factors and the similarities in approach and early management. It emphasizes the importance of early identification and basic workup for these patients, as well as the most effective early antithrombotic therapies to date. The article also emphasizes the significance of controlling risk factors and concludes with a discussion of treatment strategies based on specific stroke etiologies.

From lab coats to clinical trials: Evolution and application of electromagnetic fields for ischemic stroke rehabilitation and monitoring

Stroke is a neurovascular disorder which stands as one of the leading causes of death and disability worldwide, resulting in motor and cognitive impairment. Although the treatment approach depends on the time elapsed, the type of stroke and the availability of care centers, common interventions include thrombectomy or the administration of a tissue plasminogen activator (tPA). While these methods restore blood flow, they fall short in helping patients regain lost function. With that, recent years have seen a rise in novel methods, one of which is the use of electromagnetic fields (EMFs). Due to their ability to impact the charges in their vicinity, thereby altering the immune response and cell signaling, EMFs became suitable candidates for stroke rehabilitation. Based on their characteristics, therapeutic EMFs can be categorized into transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), pulsed (PEMFs) and low frequency (LF-EMFs) electromagnetic fields, among others. In addition to treatment, EMFs are being explored for stroke monitoring, utilizing external EMFs for imaging or recording innate EMFs linked to neural activity. Drawing from research on the effects of EMFs, this review aims to provide a comprehensive overview of the physical principles and molecular mechanisms underlying the action of EMFs, along with a discussion of their application in preclinical studies and clinical trials. Finally, this paper not only addresses the importance of treatment availability and potential side-effects, but also delves into the technical and ethical challenges associated with the use of EMFs, while exploring their prospects and future opportunities.

The value of MRI in transient ischemic attack/minor stroke following a negative CT for predicting subsequent stroke

BACKGROUND

Diffusion weighted magnetic resonance imaging's (MRI) role in predicting subsequent strokes beyond the validated Canadian TIA Score in in transient ischemic attack (TIA)/minor stroke patients with normal CT scans is unknown. In this study, we assessed the incidence of acute cerebral infarction on MRI in these patients, overall and stratified by the Canadian TIA Score levels and then we assessed subsequent stroke rates at 7, 30 and 90 days based on the presence of acute infarct on MRI.

METHODS

This pre-planned substudy of the Canadian TIA risk score cohort was conducted across 13 Canadian emergency departments over an 11-year period. Eligible patients included adult TIA/minor stroke patients with negative CT scans who underwent MRI within 7 days.

RESULTS

Among 11,507 patients, 1048 with negative CT scans had early MRI, which revealed infarction in 330 (31.5%) patients. Acute infarction rates varied by Canadian TIA Score risk group: 130 (15.4%) in low-risk, 754 (30.4%) in medium-risk, and 162 (50.0%) in the high-risk group. At 90 days, the rates of stroke in patients with a positive MRI were 2 (10.0%), 168 (22.3%), and 40 (24.7%) in low-risk, medium-risk, and high-risk groups, respectively. In comparison, in patients with a negative MRI the rate was 1 (0.9%), 7 (1.3%), and 4 (4.9%).

CONCLUSIONS

Combining the Canadian TIA Risk Score with follow-up MRI improves stroke risk assessment. MRI enhance the accuracy of diagnosis TIA, especially when CT is negative. The risk score helps prioritize MRI, benefiting medium-risk patients most, while high-risk patients need prompt management regardless of MRI results. Low-risk patients benefit from MRI for determining further investigations.

Transient Ischemic Attack in Women: Real-World Hospitalization Incidence, Outcomes, and Risk of Hemorrhage and Stroke

BACKGROUND

Sex-specific differences in stroke risk factors, clinical presentation, and outcomes are well documented. However, little is known about real-world differences in transient ischemic attack (TIA) hospitalizations and outcomes between men and women.

METHODS

This was a retrospective cohort study of the 2016 to 2021 Nationwide Readmissions Database in the United States. Adult patients hospitalized for TIA were included. Annual incidences of TIA hospitalizations for men and women were calculated using the US Census Bureau data. Primary end points were 90-day readmission for ischemic stroke or hemorrhage and compared between men and women. Demographics and comorbidities were captured and used to adjust for confounders using propensity score matching and logistic regression models.

RESULTS

A total of 588 499 patients were identified; 326 794 (55.5%) were women. The estimated annual incidence of TIA hospitalizations was 42.4 (95% CI, 26.0-58.9) per 100 000 women and 36.2 (95% CI, 23.5-48.9) per 100 000 men (relative risk, 1.17 [95% CI, 1.13-1.21]; P<0.001). Overall, women were older, had higher rates of headache and psychiatric comorbidities, and had lower rates of vascular risk factors compared with men. Women were significantly less likely to be readmitted for ischemic stroke (hazard ratio, 0.86 [95% CI, 0.79-0.93]; P<0.001) and more likely to be readmitted for hemorrhage (hazard ratio, 1.12 [95% CI, 1.04-1.20]; P<0.001), with similar rates of antithrombotic use at the time of readmissions (P>0.05). Compared with ischemic stroke, hemorrhage readmissions were significantly associated with lower odds of home discharge (odds ratio, 0.83 [95% CI, 0.76-0.91]; P<0.001) and higher odds of death (odds ratio, 3.01 [95% CI, 2.35-3.87]; P<0.001).

CONCLUSIONS

Women have a higher incidence of TIA hospitalizations than men, which may be due to higher rates of nonischemic causes of transient neurological symptoms as evidenced by differences in baseline characteristics and lower rates of subsequent ischemic stroke. Future studies are needed to better characterize transient neurological symptoms in women to avoid excess hospitalizations and unnecessary treatments that may increase hemorrhage risk.

THE DIAGNOSIS AND TREATMENT OF ASYMPTOMATIC AND SYMPTOMATIC PATIENTS WITH CAROTID ARTERY STENOSIS

Carotid artery atherosclerotic stenosis is an important annual cause of stroke in the United States. Moreover, the incidence of carotid artery stenosis is significantly increasing due to the widespread popularity of high fat and high salt diets, sedentary lifestyles, and the increasing age of the population. Of major importance to cardiovascular specialists is the fact that individuals with atherosclerotic carotid artery stenosis can have a prevalence of atherosclerotic coronary artery disease as high as 50 to 75%. Vascular screening for carotid artery stenosis with Doppler ultrasound should be considered for all symptomatic patients with possible carotid stenosis and also considered for asymptomatic patients with (1) symptomatic peripheral arterial disease, coronary artery disease, or atherosclerotic aortic aneurysm or, (2) multiple atherosclerotic risk factors. Carotid artery atherosclerotic plaques that are at high risk for rupture and thrombosis or cerebral embolization are characterized by large lipid cores, intraplaque hemorrhage, thin fibrous caps less than 165 μms that are infiltrated by macrophages and T cells or have surface ulcer(s) or fissures. Carotid artery plaque rupture with cerebral embolism can cause a stroke, TIA, or ipsilateral blindness (amaurosis fugax). Medical treatment based on the recommendations of the American and European Societies for Vascular Surgery for symptomatic patients with carotid stenosis and also asymptomatic patients with high risk carotid stenosis plaques include antiplatelet drugs, antihypertensive drugs for hypertension control and lipid lowering drugs. Management strategies and decisions about carotid revascularization in asymptomatic patients with high risk carotid stenosis should involve a multidisciplinary team and shared decision-making is recommended. The 30 day and five to 10 year outcomes in asymptomatic carotid stenosis patients who have undergone carotid endarterectomy, carotid stenting and/or optimal medical therapy are summarized from the Veterans Administration Cooperative Study, the Asymptomatic Carotid Atherosclerosis Study and the Asymptomatic Carotid Surgery Trials. The current Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) should help to resolve the debate regarding carotid artery revascularization versus primary medical treatment in asymptomatic patients with >70% carotid artery stenosis. Symptomatic patients who present within 4.5 hours of stroke onset require evaluation for acute pharmacologic intravenous thrombolysis and patients who present with large vessel occlusion within 24 hours of symptom onset should be considered for mechanical thrombectomy to reduce the neurologic deficit. Patients with carotid artery stenosis who present with a history of cerebral infarct in the preceding six months due to cerebral embolism require medical treatment and evaluation by a multidisciplinary team for carotid revascularization in order to prevent future strokes or transient ischemic attacks. The outcomes of the North American Symptomatic Carotid Endarterectomy Trial, Carotid Revascularization Endarterectomy Versus Stent Trial, Stent-Supported Percutaneous Angioplasty of the Carotid Artery vs. Endarterectomy Trial, and the Safety and Efficacy Study for Reverse Flow Used during Carotid Artery Stenting Procedure trials for symptomatic patients with carotid stenosis are reviewed. A synopsis of treatment guidelines for symptomatic and asymptomatic carotid stenosis patients from the American and European Societies of Vascular Surgery and the American Heart Association/American Stroke Association are presented. Each patient with carotid artery stenosis must be carefully evaluated to determine the best treatment based on the clinical presentation, the imaging and laboratory diagnostic information, the treatment guidelines, and the patient needs, preferences as well as the patient's social and cultural factors.

Hemodynamic evaluation of symptomatic and asymptomatic intracranial atherosclerotic stenosis using cerebral angiographic images: an exploratory study

BACKGROUND

Previous studies suggest that it may be inappropriate to determine treatment strategies solely based on the degree of stenosis for patients with intracranial atherosclerotic stenosis (ICAS). In order to better risk stratify patients with ICAS, we developed a novel non-invasive fractional flow (FF) calculation technique based on intracranial angiography (Angio-FF) to assess the hemodynamics for patients with ICAS. This study aims to investigate the difference in FF between symptomatic and asymptomatic patients with ICAS and its potential optimal threshold.

METHODS

A total of 124 patients with ICAS with severe intracranial stenosis who had undergone cerebral angiography were recruited. According to the time of onset, the patients were divided into a symptomatic ICAS group (n=78) and an asymptomatic ICAS group (n=46). The Angio-FF of each group was collected and compared. Receiver-operating characteristic curve (ROC) analysis was performed to assess the discriminative ability of Angio-FF to predict hemodynamics for ICAS.

RESULTS

Compared with the asymptomatic ICAS group, the symptomatic ICAS group had a significantly lower Angio-FF (0.75 (0.66-0.85) vs 0.85 (0.77-0.89), P<0.001). The optimal cut-off value of Angio-FF for distinguishing symptomatic ICAS from asymptomatic ICAS was 0.785 (sensitivity 71.74%, specificity 57.69%).

CONCLUSIONS

Patients with Angio-FF <0.7853 may be more prone to intracranial ischemic events. Angio-FF of 0.7853 can serve as a boundary for whether patients with ICAS exhibit clinical symptoms.

Incident Stroke After First-Time TIA According to ABCD2 Score: A Nationwide Cohort Study

BACKGROUND AND OBJECTIVES

Transient ischemic attack (TIA) is associated with a higher short-term incidence of stroke. However, long-term data on this association are lacking. Therefore, this study aimed to determine the long-term incidence of ischemic stroke after TIA according to ABCD2 score and to identify factors associated with stroke after TIA.

METHODS

All Danish patients ≥18 years with first-time TIA were included from the Danish Stroke Registry (2014-2020). The study population was stratified into a high-risk (≥4 points) and low-risk (<4 points) group according to the modified ABCD2 score (age ≥60 years, hypertension, clinical features, and diabetes). The 3-year cumulative incidence of stroke and all-cause mortality was assessed using the Aalen-Johansen and Kaplan-Meier estimators, respectively. Factors associated with 3-year stroke rate were identified using multivariable Cox regression models.

RESULTS

In total, 21,433 patients with first-time TIA were included: 1,280 (6.0%) in the high-risk group and 20,153 (94.0%) in the low-risk group. Patients with high-risk ABCD2 scores were older (median 77.5 [P25-P75 70.8-84.1] vs 70.3 [P25-P75 60.1-78.2]), more often female (53.1%), had more comorbidities (e.g., ischemic heart disease, heart failure, and atrial fibrillation), and received more medication (e.g., any antiplatelet therapy or oral anticoagulants and cholesterol-lowering drugs) at baseline. The 3-year cumulative incidence of stroke after TIA was 6.0% (95% CI 4.6-7.5) in the high-risk group and 4.2% (95% CI 3.9-4.5) in the low-risk group (p = 0.004) with an unadjusted hazard ratio (HR) 1.56 (95% CI 1.21-2.00). Factors associated with 3-year stroke rate included age ≥60 years (HR 2.21, 95% CI 1.76-2.78), current smoking (HR 1.37, 95% CI 1.13-1.65), unilateral weakness (HR 1.25, 95% CI 1.04-1.51), peripheral artery disease (HR 1.53, 95% CI 1.09-2.14), and chronic kidney disease (HR 1.39, 95% CI 1.01-1.90). The 3-year cumulative incidence of all-cause mortality was 28.9% (95% CI 26.1-31.7) in the high-risk group and 10.3% (95% CI 9.9-10.8) in the low-risk group.

DISCUSSION

Patients with high-risk ABCD2 score had an almost 60% higher associated long-term rate of ischemic stroke compared with those with low-risk ABCD2 score. Future trials focusing on preventive strategies, including evidence-based antithrombotic strategies, especially for the high-risk group are warranted.

Evaluating the Clinical Impact of a Polyphenol-Rich Extract from Salicornia ramosissima on Patients with Transient Ischemic Attack and Minor Stroke

Transient ischemic attack (TIA) is a well-established risk factor for future strokes, making interventions that target recovery and vascular risk crucial. This study aimed to assess the safety and clinical effects of a polyphenol-rich Salicornia ramosissima extract in post-TIA patients. A randomized, triple-blind, placebo-controlled trial was conducted with participants who had a history of TIA or minor stroke and who received 1 g of Salicornia extract or placebo over 11 months. Biochemical analyses, neuropsychological assessments (MOCA test), and gait and aerobic performance tests were conducted at the beginning and the end of the study. A total of 118 individuals were screened, with 80 finally included. Importantly, no significant adverse events were reported throughout the study. A neurological analysis showed an improvement in MOCA scores in patients treated with the Salicornia extract for 11 months. The treatment did not affect spatiotemporal gait parameters, but it significantly reduced blood pressure at baseline and after the aerobic performance test. Biochemically, both groups exhibited mild hyperhomocysteinemia at baseline; however, Salicornia treatment significantly lowered homocysteine levels, bringing them within the normal range. These findings highlight the safety of the Salicornia extract in patients at a high cerebrovascular risk and suggest it as a potential therapeutic option for managing vascular risk factors, such as hyperhomocysteinemia and hypertension. However, further studies are required to confirm the underlying mechanisms and explore broader clinical applications.

The Level of Fibrinogen-to-Albumin Ratio Was Associated with the Severity of Cerebral Small Vessel Disease in Patients with Transient Ischemic Attack

Purpose

Inflammation plays a role in cerebral small vessel disease (CSVD) pathophysiology. This study aimed to explore the association of the fibrinogen-to-albumin ratio (FAR), a novel inflammatory marker, with CSVD burden in patients with transient ischemic attack (TIA).

Patients and Methods

From October 1, 2022, to November 30, 2023, continuous patients with TIA were recruited in the study. The total CSVD burden score and modified total CSVD burden score were used to assess the severity of CSVD. Multivariable regression analysis was used to explore the correlation between the FAR and CSVD in TIA patients.

Results

A total of 455 participants were recruited, of whom 225 (48.35%), according to the total CSVD burden score, and 181 (40.67%), according to the modified CSVD burden score were finally identified as moderate-severe CSVD. Spearman correlation analysis showed that levels of FAR correlated with the total CSVD (r=0.392, P<0.001) and the modified total CSVD burden scores (r=0.379, P<0.001). Multivariable logistic regression analysis showed that FAR was independently associated with moderate-severe CSVD, both as a continuous variable and as a tertile variable (P<0.001).

Conclusion

The level of FAR on admission was independently associated with the severity of CSVD in patients with TIA.

NeuroMix with MRA: A Fast MR Protocol to Reduce Head and Neck CTA for Patients with Acute Neurologic Presentations

BACKGROUND AND PURPOSE

Overuse of CT-based cerebrovascular imaging in the emergency department and inpatient settings, notably CTA of the head and neck for minor and nonfocal neurologic presentations, stresses imaging services and exposes patients to radiation and contrast. Furthermore, such CT-based imaging is often insufficient for definitive diagnosis, necessitating additional MR imaging. Recent advances in fast MRI may allow timely assessment and a reduced need for head and neck CTA in select populations.

MATERIALS AND METHODS

We identified inpatients or patients in the emergency department who underwent CTAHN (including noncontrast and postcontrast head CT, with or without CTP imaging) followed within 24 hours by a 3T MRI study that included a 2.5-minute unenhanced multicontrast sequence (NeuroMix) and a 5-minute intracranial time of flight MRA) during a 9-month period (April to December 2022). Cases were classified by 4 radiologists in consensus as to whether NeuroMix and NeuroMix + MRA detected equivalent findings, detected unique findings, or missed findings relative to CTAHN.

RESULTS

One hundred seventy-four cases (mean age, 67 [SD, 16] years; 56% female) met the inclusion criteria. NeuroMix alone and NeuroMix + MRA protocols were determined to be equivalent or better compared with CTAHN in 71% and 95% of patients, respectively. NeuroMix always provided equivalent or better assessment of the brain parenchyma, with unique findings on NeuroMix and NeuroMix + MRA in 35% and 36% of cases, respectively, most commonly acute infarction or multiple microhemorrhages. In 8/174 cases (5%), CTAHN identified vascular abnormalities not seen on the NeuroMix + MRA protocol due to the wider coverage of the cervical arteries by CTAHN.

CONCLUSIONS

A fast MR imaging protocol consisting of NeuroMix + MRA provided equivalent or better information compared with CTAHN in 95% of cases in our population of patients with an acute neurologic presentation. The findings provide a deeper understanding of the benefits and challenges of a fast unenhanced MR-first approach with NeuroMix + MRA, which could be used to design prospective trials in select patient groups, with the potential to reduce radiation dose, mitigate adverse contrast-related patient and environmental effects, and lessen the burden on radiologists and health care systems.

Possible clinical and radiological predictors of haemorrhagic transformation in acute stroke patients undergoing dual antiplatelet therapy: a clinical study

Background

The predictors of intracranial haemorrhagic transformation (HT) in acute ischaemic stroke (AIS) patients undergoing dual antiplatelet therapy (DAPT) are not well known.

Objectives

The aim of this study is to identify the possible clinical and radiological predictors of HT in patients, irrespective of clinical indication for this treatment.

Design

This study is a monocentric cohort retrospective study.

Methods

We enrolled consecutive AIS patients, from our prospective register, admitted to Stroke Unit between June 2021 and June 2023 undergoing DAPT with Acetylsalicylic Acid and Clopidogrel within 72 h from symptoms onset. According to current guidelines, DAPT indication was for patients with a minor stroke, symptomatic intracranial artery stenosis and carotid angioplasty stenting. We collected clinical, demographical and radiological data. We used ABC/2 method to measure stroke volume in magnetic resonance imaging (MRI)/Diffusion-weighted imaging (DWI) sequences performed within 48 h. The primary outcome was the presence of HT at non-contrast brain computed tomography, performed 7 days after commencing DAPT.

Results

One hundred ninety-four patients were included. Twenty-eight (14.4%) presented HT. Higher NIH Stroke Scale (NIHSS) and MRI/DWI lesion volume related to increased risk of HT (p < 0.001). Reperfusion therapy and mechanical thrombectomy (MT), stent placement and a loading dose (LD) of dual antiplatelet or Clopidogrel were associated with a higher occurrence of HT (p < 0.05). Furthermore, we individuated an NIHSS cut-off value >4 (area under the curve (AUC) 0.80, sensitivity 0.82, specificity 0.65) and a volume cut-off value >8.2 ml (AUC 0.82, sensitivity 0.79, specificity 0.80) associated with an increased risk of HT (respectively, adjusted odds ratio (adj. OR) 6.5, confidence interval (CI) 1.3-32.7, p = 0.024 and adj. OR 11.0, CI 3.1-39.2, p < 0.001).

Conclusion

In clinical practice, MT treatment, antiplatelet LD administration, stent placement and clinical severity may relate to a higher risk of HT in patients with AIS and DAPT in the acute phase. In particular, we found that lesion volume cut-off could help to identify patients at greater risk of HT, regardless of the indication for DAPT.

Emergency medicine updates: Transient ischemic attack

INTRODUCTION

Transient ischemic attack (TIA) is a condition commonly evaluated for in the emergency department (ED). Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning TIA for the emergency clinician.

DISCUSSION

TIA is a harbinger of ischemic stroke and can result from a variety of pathologic causes. While prior definitions incorporated symptoms resolving within 24 h, modern definitions recommend a tissue-based definition utilizing advanced imaging to evaluate for neurologic injury and the etiology. In the ED, emergent evaluation includes assessing for current signs and symptoms of neurologic dysfunction, appropriate imaging to investigate for minor stroke or stroke risk, and arranging appropriate disposition and follow up to mitigate risk of subsequent ischemic stroke. Imaging should include evaluation of great vessels and intracranial arteries, as well as advanced cerebral imaging to evaluate for minor or subclinical stroke. Non-contrast computed tomography (CT) has limited utility for this situation; it can rule out hemorrhage or a large mass causing symptoms but should not be relied on for any definitive diagnosis. Noninvasive imaging of the cervical vessels can also be used (CT angiography or Doppler ultrasound). Treatment includes antithrombotic medications if there are no contraindications. Dual antiplatelet therapy may reduce the risk of recurrent ischemic events in higher risk patients, while anticoagulation is recommended in patients with a cardioembolic source. A variety of scoring systems or tools are available that seek to predict stroke risk after a TIA. The Canadian TIA risk score appears to have the best diagnostic accuracy. However, these scores should not be used in isolation. Disposition may include admission, management in an ED-based observation unit with rapid diagnostic protocol, or expedited follow-up in a specialty clinic.

CONCLUSIONS

An understanding of literature updates concerning TIA can improve the ED care of patients with TIA.

Fibrin clot permeability (Ks) in patients on left ventricular assist device

Patients on left ventricular assist devices (LVAD) are prone to excessive hemostasis disturbances due to permanent contact of artificial pump surfaces with blood components. We aimed to investigate if fibrin clot permeability is altered in patients on long-term continuous-flow LVAD therapy and if the clot permeability is associated with clinical characteristics and adverse events. We investigated 85 end-stage heart failure patients (90.6% men, age 48.6-63.8 years) scheduled for continuous flow long-term LVAD support according to current clinical indications. The patients were assessed periodically: prior to LVAD implantation (T1), 3-6 months (T2) after LVAD implantation, 6-12 months after (T3) and then every 6 months. We tested the first three blood samples (T1-T3) and the last available blood sample (T4), but no longer than 5 years after LVAD implantation. We assessed hemostasis parameters (Activated Partial Thromboplastin Time (APTT) Prothrombin Time, Activated Partial Thromboplastin Time, Fibrinogen, D-dimer, Antithrombin, Thrombin Time, Factor VIII, and von Willebrand Factor, aspirin-induced platelet inhibition, adenosine-diphosphate test) changes during the study period. Fibrin Clot Permeability was evaluated using a pressure system and Permeability Coefficient (Ks) was calculated. We observed a decrease in fibrin clot permeability (Ks) between T1, T2, T3 and T4 time periods; P < 0.01 for each comparison. Fibrin clot permeability was negatively correlated with fibrinogen concentration: r = - 0.51, P < 0.001, factor VIII activity r = - 0.42, P < 0.001. There was no association of Ks with age, Left Ventricular Ejection Fraction (LVEF) and medications P > 0.001, however cumulative measurements in patients on aspirin showed shortening of Ks in this group P = 0.0123. Major adverse cardiac and cerebrovascular events (MACCE) occurred in 36.5% patients, bleeding events in 25.9%, Net Adverse Clinical Events (NACE) in 62.4%; 31.7% patients died, and 17.6% underwent transplantation. The transplantation was considered as the endpoint. Discrepancies in Ks were observed between patients with MACCE, bleeding, and NACE, and patients without adverse events. Ks showed a constant trend towards normalization (P < 0.01) only in patients without adverse events. Patients with advanced heart failure have disturbed clot structure. A trend towards normalization of the Ks values is associated with fewer thromboembolic and bleeding complications in this group of patients.

Consensus paper on the management of acute isolated vertigo in the emergency department

Acute vertigo is defined as the perception of movement of oneself or the surroundings in the absence of actual motion and it is a frequent cause for emergency department admissions. The utilization of medical resources and the duration of hospital stay for this kind of symptom is high. Furthermore, the efficiency of brain imaging in the acute phase is low, considering the limited sensitivity of both CT and MRI for diagnosing diseases that are the causes of central type of vertigo. Relying on imaging tests can provide false reassurance in the event of negative results or prolong the in-hospital work-up improperly. On the other hand, clinical examinations, notably the assessment of nystagmus' features, have proven to be highly accurate and efficient when performed by experts. Literature data point out that emergency physicians often do not employ these skills or use them incorrectly. Several clinical algorithms have been introduced in recent years with the aim of enhancing the diagnostic accuracy of emergency physicians when evaluating this specific pathology. Both the 'HINTS and 'STANDING' algorithms have undergone external validation in emergency physician hands, showing good diagnostic accuracy. The objective of this consensus document is to provide scientific evidence supporting the clinical decisions made by physicians assessing adult patients with acute vertigo in the emergency department, particularly in cases without clear associated neurological signs. The document aims to offer a straightforward and multidisciplinary approach. At the same time, it tries to delineate benchmarks for the formulation of local diagnostic and therapeutic pathways, as well as provide a base for the development of training and research initiatives.

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization

BACKGROUND

Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease.

METHODS

The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023.

RESULTS

A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate.

CONCLUSIONS

OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.

An Alternative Photothrombotic Model of Transient Ischemic Attack

Animal models mimicking human transient ischemic attack (TIA) and cerebral microinfarcts are essential tools for studying their pathogenetic mechanisms and finding methods of their treatment. Despite its advantages, the model of single arteriole photothrombosis requires complex experimental equipment and highly invasive surgery, which may affect the results of further studies. Hence, to achieve high translational potential, we focused on developing a TIA model based on photothrombosis of arterioles to combine good reproducibility and low invasiveness. For the first time, noninvasive laser speckle contrast imaging (LSCI) was used to monitor blood flow in cerebral arterioles and reperfusion was achieved. We demonstrate that irradiation of mouse cerebral cortical arterioles using a 532-nm laser with a 1-mm-wide beam at 2.4 or 3.7 mW for 55 or 40 s, respectively, after 15 mg/kg intravenous Rose Bengal administration, induces similar ischemia-reperfusion lesions resulting in microinfarct formation. The model can be used to study the pathogenesis of spontaneously developing cerebral microinfarcts in neurodegeneration. Reducing the exposure times by 10 s while maintaining the same other parameters caused photothrombosis of the arteriole with reperfusion in less than 1 h. This mode of photodynamic exposure caused cellular and subcellular level ischemic changes in neurons and promoted the activation of astrocytes and microglia in the first day after irradiation, but not later, without the formation of microinfarcts. This mode of photodynamic exposure most accurately reproduced human TIA, characterized by the absence of microinfarcts.

Increased incidence of napkin-ring sign plaques on cervicocerebral computed tomography angiography associated with the risk of acute ischemic stroke occurrence

OBJECTIVES

Carotid atherosclerosis plays an essential role in the occurrence of ischemic stroke. This study aimed to investigate whether a larger burden of napkin-ring sign (NRS) plaques on cervicocerebral computed tomography angiography (CTA) increased the risk of acute ischemic stroke (AIS).

METHODS

This retrospective, single-center, cross-sectional study enrolled patients with NRS plaques identified in the subclavian arteries, brachiocephalic trunk, carotid arterial system, and vertebrobasilar circulation on contrast-enhanced cervicocerebral CTA. Patients were divided into AIS and non-AIS groups based on imaging within 12 h of symptom onset. Univariate and multivariate logistic regression analyses were performed to determine the risk factor of AIS occurrence.

RESULTS

A total of 202 patients (66.72 years ± 8.97, 157 men) were evaluated. Plaques with NRS in each subject of the AIS group (N = 98) were significantly more prevalent than that in the control group (N = 104) (1.96 ± 1.17 vs 1.41 ± 0.62). In the AIS group, there were substantially more NRS plaques on the ipsilateral side than contralateral side (1.55 ± 0.90 vs. 0.41 ± 0.66). NRS located on the ipsilateral side of the AIS showed an area under the receiver curve (AUC) of 0.86 to identify ischemic stroke. NRS plaque amounts were an independent risk factor for AIS occurrence (odds ratio, 1.86) after adjusting for other factors.

CONCLUSIONS

Increased incidence of napkin-ring sign plaques on cervicocerebral CTA was positively associated with AIS occurrence, which could aid in detecting asymptomatic atherosclerotic patients at high risk of AIS in routine screening or emergency settings.

CLINICAL RELEVANCE STATEMENT

Napkin-ring sign plaque provides an important imaging target for estimating acute ischemic stroke risk and identifying high-risk patients in routine screening or emergency settings, so that timely anti-atherosclerotic therapy can be used for prevention.

KEY POINTS

• This cross-sectional study investigated the association between high-risk carotid artery plaques and acute ischemic stroke. • Increased incidence of napkin-ring sign plaques on cervicocerebral computed tomography angiography is positively associated with acute ischemic stroke occurrence. • Napkin-ring signs help identify risky patients prone to acute ischemic stroke to facilitate prevention.

ABCD2-I Score Predicts Unplanned Emergency Department Revisits within 72 Hours Due to Recurrent Acute Ischemic Stroke

BACKGROUND

the ABCD2 score is valuable for predicting early stroke recurrence after a transient ischemic attack (TIA), and Doppler ultrasound can aid in expediting stroke triage. The study aimed to investigate whether combining the ABCD2 score with carotid duplex results can enhance the identification of early acute ischemic stroke after TIA.

METHODS

we employed a retrospective cohort design for this study, enrolling patients diagnosed with TIA who were discharged from the emergency department (ED). The modified ABCD2-I (c50) score, which incorporates a Doppler ultrasound assessment of internal carotid artery stenosis > 50%, was used to evaluate the risk of acute ischemic stroke within 72 h. Patients were categorized into three risk groups: low risk (with ABCD2 and ABCD2-I scores = 0-4), moderate risk (ABCD2 score = 4-5 and ABCD2-I score = 5-7), and high risk (ABCD2 score = 6-7 and ABCD2-I score = 8-9).

RESULTS

between 1 January 2014, and 31 December 2019, 1124 patients with new neurological deficits were screened, with 151 TIA patients discharged from the ED and included in the analysis. Cox proportional hazards analysis showed that patients in the high-risk group, as per the ABCD2-I (c50) score, were significantly associated with revisiting the ED within 72 h due to acute ischemic stroke (HR: 3.12, 95% CI: 1.31-7.41, p = 0.0102), while the ABCD2 alone did not show significant association (HR: 1.12, 95% CI: 0.57-2.22, p = 0.7427).

CONCLUSION

ABCD2-I (c50) scores effectively predict early acute ischemic stroke presentations to the ED within 72 h after TIA.

Enhancing stroke risk prediction in patients with transient ischemic attack: insights from a prospective cohort study implementing fast-track care

Background and aims

Fast-track care have been proved to reduce the short-term risk of stroke after transient ischemic attack (TIA). We aimed to investigate stroke risk and to characterize short- and long-term stroke predictors in a large cohort of TIA patients undergoing fast-track management.

Methods

Prospective study, enrolling consecutive TIA patients admitted to a Northern Italy emergency department from August 2010 to December 2017. All patients underwent fast-track care within 24 h of admission. The primary outcome was defined as the first stroke recurrence at 90 days, 12 and 60 months after TIA. Stroke incidence with 95% confidence interval (CI) at each timepoint was calculated using Poisson regression. Predictors of stroke recurrence were evaluated with Cox regression analysis. The number needed to treat (NNT) of fast-track care in preventing 90-day stroke recurrence in respect to the estimates based on baseline ABCD2 score was also calculated.

Results

We enrolled 1,035 patients (54.2% males). Stroke incidence was low throughout the follow-up with rates of 2.2% [95% CI 1.4-3.3%] at 90 days, 2.9% [95% CI 1.9-4.2%] at 12 months and 7.1% [95% CI 5.4-9.0%] at 60 months. Multiple TIA, speech disturbances and presence of ischemic lesion at neuroimaging predicted stroke recurrence at each timepoint. Male sex and increasing age predicted 90-day and 60-month stroke risk, respectively. Hypertension was associated with higher 12-month and 60-month stroke risk. No specific TIA etiology predicted higher stroke risk throughout the follow-up. The NNT for fast-track care in preventing 90-day stroke was 14.5 [95% CI 11.3-20.4] in the overall cohort and 6.8 [95% CI 4.6-13.5] in patients with baseline ABCD2 of 6 to 7.

Conclusion

Our findings support the effectiveness of fast-track care in preventing both short- and long-term stroke recurrence after TIA. Particular effort should be made to identify and monitor patients with baseline predictors of higher stroke risk, which may vary according to follow-up duration.

Comparison of vascular risk profile and clinical outcomes among patients with central (branch) retinal artery occlusion versus amaurosis fugax

BACKGROUND

Retinal artery occlusions lead to sudden, painless vision loss, affecting millions globally. Despite their significance, treatment strategies remain unestablished, contrasting with acute ischemic stroke (AIS), where IVT has proven efficacy. Similar to AIS, retinal artery occlusions demand urgent evaluation and treatment, reflecting the principle "time is retina". Even for patients with transient monocular vision loss, also known as amaurosis fugax (AF), pertinent guidelines meanwhile recommend immediate emergency assessment in a specialized facility. However, data on the clinical benefit and comparability with persistent occlusions are missing. This study aimed to compare the results of a comprehensive stroke-workup among patients with persistent retinal artery occlusions (RAO), including both central retinal (CRAO) and branch retinal artery occlusion (BRAO) and those with AF.

METHODS

Conducted at the University Hospital Giessen, Germany, this exploratory cross-sectional study enrolled patients with transient or permanent unilateral vision loss of non-arteritic origin. The primary outcome were differences between the two groups RAO and AF with regard to cardiovascular risk profiles and comorbidities, vascular and pharmacological interventions and clinical neurological and ophthalmological outcomes. Secondary outcome was a sub-group analysis of patients receiving IVT.

RESULTS

Out of 166 patients assessed, 76 with RAO and 40 with AF met the inclusion criteria. Both groups exhibited comparable age, gender distribution, and cardiovascular risk profiles. Notably, RAO patients did not show significantly more severe vascular comorbidities than AF patients. However, AF patients received vascular interventions more frequently. Pharmacological intervention rates were similar across groups. RAO patients had slightly worse neurological outcomes, and IVT did not yield favorable ophthalmological outcomes within any observed patients.

CONCLUSION

The study found similar vascular burden and risk factors in patients with RAO and AF, with implications for clinical workflows. IVT for RAO may only be effective in very early treatment windows. This emphasizes the need for public awareness and collaborative protocols between ophthalmologists and neurologists to improve outcomes.

SEA 2024 Standards for Global Control of Vascular Risk

One of the objectives of the Spanish Society of Arteriosclerosis is to contribute to the knowledge, prevention and treatment of vascular diseases, which are the leading cause of death in Spain and entail a high degree of disability and health expenditure. Atherosclerosis is a multifactorial disease and its prevention requires a global approach that takes into account the associated risk factors. This document summarises the current evidence and includes recommendations for patients with established vascular disease or at high vascular risk: it reviews the symptoms and signs to evaluate, the laboratory and imaging procedures to request routinely or in special situations, and includes the estimation of vascular risk, diagnostic criteria for entities that are vascular risk factors, and general and specific recommendations for their treatment. Finally, it presents aspects that are not usually referenced in the literature, such as the organisation of a vascular risk consultation.

[Functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]

The review is devoted to diagnosis and treatment of internal carotid artery tortuosity. The authors consider modern classification, epidemiology and diagnostic options using neuroimaging or ultrasound-assisted functional stress tests depending on medical history and complaints. In addition to standard Doppler ultrasound, rotational and orthostatic tests are advisable due to possible changes of local shape and hemodynamic parameters following body position changes, especially in patients with concomitant atherosclerotic stenosis. Thus, a personalized approach is especially important for treatment and diagnostics of internal carotid artery tortuosity.

Racial Impact on Inpatient Stroke Quality of Care in Two Community Hospitals

INTRODUCTION

This analysis was conducted as a part of a quality improvement project aiming at identifying racial disparity in inpatient stroke quality of care.

METHODS

The Get With The Guidelines (GWTG) database was used to identify all patients discharged with any stroke diagnosis between January and December 2021. An additional chart review was conducted to ensure the accuracy of racial/ethnic categorization. The sample was dichotomized into white vs. non-white groups and compared with univariate analysis.

RESULTS

The study sample comprised 1408 encounters (1347 patients) with Mean age of 71 ± 15 years, 51% women, 82% white patients, 15% non-white patients, 72% acute ischemic stroke (AIS); 15% transient ischemic attack (TIA), 9% intracerebral hemorrhage (ICH), 3% subarachnoid hemorrhage (SAH), and 1% stroke not otherwise specified. Non-white patients were younger and had fewer concomitant diagnoses, a lower proportion of TIA, and a higher proportion of ICH (p = 0.004). In the AIS cohort, compared to white patients, non-white patients had less frequent ambulance (p = 0.009), arrived at the hospital later than white patients (7.7 h longer; p < 0.001), had more severe strokes, and had less frequent IV thrombolysis utilization (7% vs. 13%; p = 0.042). Similarly, in the TIA cohort, non-white patients' utilization of EMS was lower than that of white patients, and their hospital arrival was delayed. In the ICH cohort, non-white patients were younger and had a lower frequency of atrial fibrillation and a non-significant trend toward higher disease severity. The SAH cohort had only eight non-white patients, six of whom were transferred to a higher level of hospital care within a few hours of arrival. Importantly, the hospital-based quality metrics, such as door-to-CT time, door-to-needle time, and the Joint Commission stroke quality metrics, were similar between the two groups.

CONCLUSIONS

There is a racial disparity in the pre-hospital phase of the stroke chain of survival of non-white patients, impacting IV thrombolysis utilization. The younger age and worse lipid profile and hemoglobin A1c of non-white patients suggest the need for better preventative care starting at a young age.

Assessing the causal effect of genetically predicted metabolites and metabolic pathways on stroke

BACKGROUND

Stroke is a common neurological disorder that disproportionately affects middle-aged and elderly individuals, leading to significant disability and mortality. Recently, human blood metabolites have been discovered to be useful in unraveling the underlying biological mechanisms of neurological disorders. Therefore, we aimed to evaluate the causal relationship between human blood metabolites and susceptibility to stroke.

METHODS

Summary data from genome-wide association studies (GWASs) of serum metabolites and stroke and its subtypes were obtained separately. A total of 486 serum metabolites were used as the exposure. Simultaneously, 11 different stroke phenotypes were set as the outcomes, including any stroke (AS), any ischemic stroke (AIS), large artery stroke (LAS), cardioembolic stroke (CES), small vessel stroke (SVS), lacunar stroke (LS), white matter hyperintensities (WMH), intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), transient ischemic attack (TIA), and brain microbleeds (BMB). A two-sample Mendelian randomization (MR) study was conducted to investigate the causal effects of serum metabolites on stroke and its subtypes. The inverse variance-weighted MR analyses were conducted as causal estimates, accompanied by a series of sensitivity analyses to evaluate the robustness of the results. Furthermore, a reverse MR analysis was conducted to assess the potential for reverse causation. Additionally, metabolic pathway analysis was performed using the web-based MetOrigin.

RESULTS

After correcting for the false discovery rate (FDR), MR analysis results revealed remarkable causative associations with 25 metabolites. Further sensitivity analyses confirmed that only four causative associations involving three specific metabolites passed all sensitivity tests, namely ADpSGEGDFXAEGGGVR* for AS (OR: 1.599, 95% CI 1.283-1.993, p = 2.92 × 10-5) and AIS (OR: 1.776, 95% CI 1.380-2.285, p = 8.05 × 10-6), 1-linoleoylglycerophosph-oethanolamine* for LAS (OR: 0.198, 95% CI 0.091-0.428, p = 3.92 × 10-5), and gamma-glutamylmethionine* for SAH (OR: 3.251, 95% CI 1.876-5.635, p = 2.66 × 10-5), thereby demonstrating a high degree of stability. Moreover, eight causative associations involving seven other metabolites passed both sensitivity tests and were considered robust. The association result of one metabolite (glutamate for LAS) was considered non-robust. As for the remaining metabolites, we speculate that they may potentially possess underlying causal relationships. Notably, no common metabolites emerged from the reverse MR analysis. Moreover, after FDR correction, metabolic pathway analysis identified 40 significant pathways across 11 stroke phenotypes.

CONCLUSIONS

The identified metabolites and their associated metabolic pathways are promising circulating metabolic biomarkers, holding potential for their application in stroke screening and preventive strategies within clinical settings.

An unusual stroke mimic: A case report

Hypokalaemic paralysis is a rare disorder characterized by rapid onset of symmetrical flaccid skeletal muscle weakness in the presence of reduced serum potassium levels. It is categorized as primary or secondary depending on the aetiology. Asymmetric or unilateral muscle weakness in hypokalaemic patients is a rare presentation. In patients with comorbid cardiovascular risk factors, this atypical manifestation can mimic acute stroke. Only a few of such cases have been reported in the literature. This report discusses the case of a 46-year-old hypertensive Ghanaian woman who presented to a District Hospital with sudden-onset right-sided flaccid weakness and a high blood pressure. Acute stroke was ruled out with computed tomography scan of the brain. Further laboratory evaluation demonstrated reduced serum potassium level, which was corrected with subsequent dramatic resolution of the muscle weakness.

Association of Incomplete Neurovascular Imaging After Emergency Department Encounters for Transient Ischemic Attack and Odds of Subsequent Stroke: A National Medicare Analysis

BACKGROUND. Multisociety guidelines recommend urgent brain and neurovascular imaging for patients with transient ischemic attack (TIA), to identify and treat modifiable stroke risk factors. Prior research suggests that most patients with TIA who present to the emergency department (ED) do not receive prompt neurovascular imaging. OBJECTIVE. The purpose of this study was to evaluate the association between incomplete neurovascular imaging workup during ED encounters for TIA and the odds of subsequent stroke. METHODS. This retrospective study obtained data from the Medicare Standard Analytical Files for calendar years 2016 and 2017; these files contain 100% samples of claims for Medicare beneficiaries. Information was extracted using ICD 10th revision (ICD-10) and CPT codes. Those patients who were discharged from an ED encounter with a TIA diagnosis and who underwent brain CT or brain MRI during or within 2 days of the encounter were identified. Patients were considered to have complete neurovascular imaging if they underwent cross-sectional vascular imaging of both the brain (brain CTA or brain MRA) and neck (neck CTA, neck MRA, or carotid ultrasound) during or within 2 days of the encounter. The association between incomplete neurovascular imaging and a new stroke diagnosis within the subsequent 90 days was tested by multivariable logistic regression analysis. RESULTS. The sample included 111,417 patients (47,370 men, 64,047 women; 26.0% older than 84 years) who had TIA ED encounters. A total of 37.3% of patients (41,592) had an incomplete neurovascular imaging workup. A new stroke diagnosis within 90 days of the TIA ED encounter occurred in 4.4% (3040/69,825) of patients with complete neurovascular imaging versus 7.0% (2898/41,592) of patients with incomplete neurovascular imaging. Incomplete neurovascular imaging was associated with increased likelihood of stroke within 90 days (OR, 1.30 [95% CI, 1.23-1.38]) after adjustment for patient characteristics (age, sex, race and ethnicity, high-risk comorbidities, median county household income) and hospital characteristics (region, rurality, number of beds, major teaching hospital designation). CONCLUSION. TIA ED encounters with incomplete neurovascular imaging were associated with higher odds of subsequent stroke occurring within 90 days. CLINICAL IMPACT. Increased access to urgent neurovascular imaging for patients with TIA may represent a target that could facilitate detection and treatment of modifiable stroke risk factors.