Addition of Brain Infarction to the ABCD 2 Score (ABCD 2 I)

PRERISK: A Personalized, Artificial Intelligence-Based and Statistically-Based Stroke Recurrence Predictor for Recurrent Stroke

BACKGROUND

Predicting stroke recurrence for individual patients is difficult, but individualized prediction may improve stroke survivors' engagement in self-care. We developed PRERISK: a statistical and machine learning classifier to predict individual risk of stroke recurrence.

METHODS

We analyzed clinical and socioeconomic data from a prospectively collected public health care-based data set of 41 975 patients admitted with stroke diagnosis in 88 public health centers over 6 years (2014-2020) in Catalonia-Spain. A new stroke diagnosis at least 24 hours after the index event was considered as a recurrent stroke, which was considered as our outcome of interest. We trained several supervised machine learning models to provide individualized risk over time and compared them with a Cox regression model. Models were trained to predict early, late, and long-term recurrence risk, within 90, 91 to 365, and >365 days, respectively. C statistics and area under the receiver operating characteristic curve were used to assess the accuracy of the models.

RESULTS

Overall, 16.21% (5932 of 36 114) of patients had stroke recurrence during a median follow-up of 2.69 years. The most powerful predictors of stroke recurrence were time from previous stroke, Barthel Index, atrial fibrillation, dyslipidemia, age, diabetes, and sex, which were used to create a simplified model with similar performance, together with modifiable vascular risk factors (glycemia, body mass index, high blood pressure, cholesterol, tobacco dependence, and alcohol abuse). The areas under the receiver operating characteristic curve were 0.76 (95% CI, 0.74-0.77), 0.60 (95% CI, 0.58-0.61), and 0.71 (95% CI, 0.69-0.72) for early, late, and long-term recurrence risk, respectively. The areas under the receiver operating characteristic curve of the Cox risk class probability were 0.73 (95% CI, 0.72-0.75), 0.59 (95% CI, 0.57-0.61), and 0.67 (95% CI, 0.66-0.70); machine learning approaches (random forest and AdaBoost) showed statistically significant improvement (P<0.05) over the Cox model for the 3 recurrence time periods. Stroke recurrence curves can be simulated for each patient under different degrees of control of modifiable factors.

CONCLUSIONS

PRERISK is a novel approach that provides a personalized and fairly accurate risk prediction of stroke recurrence over time. The model has the potential to incorporate dynamic control of risk factors.

Systematic Review of Machine Learning Applied to the Secondary Prevention of Ischemic Stroke

Ischemic stroke is a serious disease posing significant threats to human health and life, with the highest absolute and relative risks of a poor prognosis following the first occurrence, and more than 90% of strokes are attributable to modifiable risk factors. Currently, machine learning (ML) is widely used for the prediction of ischemic stroke outcomes. By identifying risk factors, predicting the risk of poor prognosis and thus developing personalized treatment plans, it effectively reduces the probability of poor prognosis, leading to more effective secondary prevention. This review includes 41 studies since 2018 that used ML algorithms to build prognostic prediction models for ischemic stroke, transient ischemic attack (TIA), and acute ischemic stroke (AIS). We analyzed in detail the risk factors used in these studies, the sources and processing methods of the required data, the model building and validation, and their application in different prediction time windows. The results indicate that among the included studies, the top five risk factors in terms of frequency were cardiovascular diseases, age, sex, national institutes of health stroke scale (NIHSS) score, and diabetes. Furthermore, 64% of the studies used single-center data, 65% of studies using imbalanced data did not perform data balancing, 88% of the studies did not utilize external validation datasets for model validation, and 72% of the studies did not provide explanations for their models. Addressing these issues is crucial for enhancing the credibility and effectiveness of the research, consequently improving the development and implementation of secondary prevention measures.

Safety and Feasibility of an Emergency Department-to-Outpatient Pathway for Patients With TIA and Nondisabling Stroke

Background and Objectives

Evaluation of transient ischemic attack/nondisabling ischemic strokes (TIA/NDS) in the emergency department (ED) contributes to capacity issues and increasing health care expenditures, especially high-cost duplicative imaging.

Methods

As an institutional quality improvement project, we developed a novel pathway to evaluate patients with TIA/NDS in the ED using a core set of laboratory tests and CT-based neuroimaging. Patients identified as 'low risk' through a safety checklist were discharged and scheduled for prompt outpatient tests and stroke clinic follow-up. In this prespecified analysis designed to assess feasibility and safety, we abstracted data from patients consecutively enrolled in the first 6 months.

Results

We compared data from 106 patients with TIA/NDS enrolled in the new pathway from April through September 2020 (age 67.9 years, 45% female), against 55 unmatched historical controls with TIA encountered from April 2016 through March 2017 (age 68.3 years, 47% female). Both groups had similar median NIHSS scores (pathway and control 0) and ABCD2 scores (pathway and control 3). Pathway-enrolled patients had a 44% decrease in mean ED length of stay (pathway 13.7 hours, control 24.4 hours, p < 0.001) and decreased utilization of ED MRI-based imaging (pathway 63%, control 91%, p < 0.001) and duplicative ED CT plus MRI-based brain and/or vascular imaging (pathway 35%, control 53%, p = 0.04). Among pathway-enrolled patients, 89% were evaluated in our stroke clinic within a median of 5 business days; only 5.5% were lost to follow-up. Both groups had similar 90-day rates of ED revisits (pathway 21%, control 18%, p = 0.84) and recurrent TIA/ischemic stroke (pathway 1%, control 2%, p = 1.0). Recurrent ischemic events among pathway-enrolled patients were attributed to errors in following the safety checklist before discharge.

Discussion

Our TIA/NDS pathway, implemented during the initial outbreak of COVID-19, seems feasible and safe, with significant positive impact on ED throughput and ED-based high-cost duplicative imaging. The safety checklist and option of virtual telehealth follow-up are novel features. Broader adoption of such pathways has important implications for value-based health care.

ABCD2 score has equivalent stroke risk prediction for anterior circulation TIA and posterior circulation TIA

Transient ischemic attack (TIA) was clinically divided into anterior circulation (AC) or posterior circulation (PC). Previous study reported that ABCD2 score could predict the stroke risk after AC-TIA but might have limitation for PC-TIA. We aimed to classify TIA depending on neuroimaging and assess the value of ABCD2 score for predicting stroke risk in different territories. Research data was from TIA database of the First Affiliated Hospital of Zhengzhou University. TIA patients with acute infarction on diffuse weighted imaging [that is, transient symptoms with infarction (TSI)] were divided into anterior and posterior circulation groups according to the location of infarction. The outcome was recurrent stroke within 7 and 90 days. The predictive power of ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses. Overall, 382 AC-TSI and 112 PC-TSI patients were included. There were 38 (9.9%) AC-TSI patients and 11(9.8%) PC-TSI patients who had recurrent stroke at 7 days, and 66 (17.3%) AC-TSI patients and 19 (17.0%) PC-TSI patients who had recurrent stroke within 90 days. At 7 days, the AUC for ABCD2 score was 0.637 (95% confidence interval CI 0.554-0.720) in anterior circulation and 0.683 (95% CI 0.522-0.845) in posterior circulation. The C statistics for ABCD2 score in the two groups were not statistically significant (Z =  - 0.499; P = 0.62). Similar result was found when the outcome time-point was set at 90 days. ABCD2 score could predict the short-term risk of recurrent stroke after AC-TSI and PC-TSI, and had similar predictive abilities for AC-TSI and PC-TSI.

Early mobilisation is associated with lower subacute blood pressure and variability in ICH: A retrospective cohort study✰

BACKGROUND

Very early rehabilitation after stroke appears to worsen outcome, particularly in intracerebral haemorrhage (ICH). Plausible mechanisms include increased mean blood pressure (BP) and BP variability.

AIMS

To test associations between early mobilisation, subacute BP and survival, in observational data of ICH patients during routine clinical care.

METHODS

We collected demographic, clinical and imaging data from 1372 consecutive spontaneous ICH patients admitted between 2 June 2013 and 28 September 2018. Time to first mobilisation (defined as walking, standing, or sitting out-of-bed) was extracted from electronic records. We evaluated associations between early mobilisation (within 24 h of onset) and both subacute BP and death by 30 days using multifactorial linear and logistic regression analyses respectively.

RESULTS

Mobilisation at 24 h was not associated with increased odds of death by 30 days when adjusting for key prognostic factors (OR 0.4, 95% CI 0.2 to 1.1, p = 0.07). Mobilisation at 24 h was independently associated with both lower mean systolic BP (-4.5 mmHg, 95% CI -7.5 to -1.5 mmHg, p = 0.003) and lower diastolic BP variability (-1.3 mmHg, 95% CI -2.4 to -0.2 mg, p = 0.02) during the first 72 h after admission.

CONCLUSIONS

Adjusted analysis in this observational dataset did not find an association between early mobilisation and death by 30 days. We found early mobilisation at 24 h to be independently associated with lower mean systolic BP and lower diastolic BP variability over 72 h. Further work is needed to establish mechanisms for the possible detrimental effect of early mobilisation in ICH.

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.

Transient ischemic attack events and incident cardiovascular and non-cardiovascular complications: Observations from a large diversified multimorbid cohort

Background:

Transient ischemic attack (TIA) is a strong signal prompting the incidence of future cardiovascular and non-cardiovascular complications, in light of recent debate on the so-called “stroke-heart syndrome.” We aimed to investigate the relation of TIAs to incident clinical events.

Methods:

Patients were drawn from three health plans with a wide spectrum of age groups and a wide mix of socio-economic/disability status. Two TIA cohorts in a retrospective design were used to achieve the study specific aims: (i) to investigate the incidence of TIA and associated cardiovascular and non-cardiovascular complications within 30 and 90 days from the onset of incident TIA events; and (ii) to examine the potential risk factors for developing incident TIA events in the general population with/without a history of prior stroke.

Results:

The incident TIA cohort consisted of 53,716 patients with an average age of 64.2 years (SD 15.2) and 46.1% male. Following TIA, the incidence proportions of ischemic stroke within 30 and 90 days were 2.7% and 3.8%, respectively, and for incident acute coronary syndrome being 0.94 and 1.84, respectively. Ventricular arrhythmia had proportions of 1.2 and 2.14, respectively within 30 and 90 days, with acute heart failure having values of 0.49 and 0.923. About 45% or more of the cardiovascular and non-cardiovascular complications occurred in the first 30 days following the incident TIA cases. About one-third of the recurrent TIA cases followed the incident TIA cases within a span of 30 days. Amongst comorbidities with stroke in the comorbid history, prior stroke provided the strongest risk factor in terms of odds ratio (OR = 8.34, 95% CI 7.21–9.66) for incident TIA events. Age was strongly associated with incident TIA events. Without a prior history of stroke (ischemic stroke/transient ischemic attack/thrombo-embolic events), valvular disease was the strongest risk factor from among the comorbidities (OR-1.87, 95% CI 1.51–2.32). Age also provided strong associations with incident TIA events.

Conclusions:

Following a TIA, there was a high risk of stroke, acute coronary syndrome, ventricular arrhythmia, acute heart failure, and non-cardiovascular complications.

ABCD2, ABCD2-I, and OTTAWA scores for stroke risk assessment: a direct retrospective comparison

Transient ischemic attack (TIA) is a neurologic emergency characterized by cerebral ischemia eliciting a temporary focal neurological deficit. Many clinical prediction scores have been proposed to assess the risk of stroke after TIA; however, studies on their clinical validity and comparisons among them are scarce. The objective is to compare the accuracy of ABCD², ABCD²-I, and OTTAWA scores in the prediction of a stroke at 7, 90 days, and 1 year in patients presenting with TIA. Single-centre, retrospective study including patients with TIA admitted to the Emergency Department of our third-level, University Hospital, between 2018 and 2019. Five hundred three patients were included. Thirty-nine (7.7%) had a stroke within 1 year from the TIA: 9 (1.7%) and 24 (4.7%) within 7 and 90 days, respectively. ABCD², ABCD²-I, and OTTAWA scores were significantly higher in patients who developed a stroke. AUROCs ranged from 0.66 to 0.75, without statistically significant differences at each time-point. Considering the best cut-off of each score, only ABCD² > 3 showed a sensitivity of 100% only in the prediction of stroke within 7 days. Among clinical items of each score, duration of symptoms, previous TIA, hemiparesis, speech disturbance, gait disturbance, previous cerebral ischemic lesions, and known carotid artery disease were independent predictors of stroke. Clinical scores have moderate prognostic accuracy for stroke after TIA. Considering the independent predictors for stroke, our study indicates the need to continue research and prompts the development of new tools on predictive scores for TIA.

External validation of ABCD series scores for predicting early stroke events following transient ischemic attack in a large nationwide registry

Introduction:

In the context of modern guideline-based strategies, new validations of prognostic scores for predicting early stroke risk are needed. We aimed to compare the validity of the ABCD series scores and assess the incremental values of risk components for predicting in-hospital stroke events in patients with transient ischemic attack (TIA).

Patients and methods:

We abstracted data from the Chinese Stroke Center Alliance (CSCA), a nationwide registry with 68,433 TIA patients admitted within 7 days of symptom onset from 1476 hospitals. TIA was defined by time-based criteria according to the World Health Organization (WHO). The discrimination of ABCD, ABCD2, ABCD2-I, and ABCD3 scores for predicting in-hospital stroke events was assessed by the area under the receiver-operating characteristics curves (AUC). The incremental predictive values of added risk predictor were determined by net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

Results:

A total of 29,286 TIA patients were included, of whom 1466 (5.0%) had in-hospital stroke events. Compared with ABCD2-I score (AUC 0.79, 95% confidence interval [CI] 0.77–0.80), ABCD (AUC 0.58, 95% CI 0.57–0.60), ABCD2 (AUC 0.58, 95% CI 0.56–0.59), and ABCD3 (AUC 0.58, 95% CI 0.56–0.60) had lower predictive utility. An incremental value was observed when adding infarction on DWI (IDI = 0.0597, NRI = 1.1036) into ABCD2 score to be ABCD2-I.

Conclusion:

The traditional scales utilizing medical history (ABCD, ABCD2, and ABCD3 scores) show fair ability for predicting in-hospital stroke events after TIA, but the ABCD2-I score, which adds infarction on DWI, improves the predictive ability.

Infarct on Brain Imaging, Subsequent Ischemic Stroke, and Clopidogrel-Aspirin Efficacy: A Post Hoc Analysis of a Randomized Clinical Trial

IMPORTANCE

In the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, acute treatment with clopidogrel-aspirin was associated with significantly reduced risk of recurrent stroke. There may be specific patient groups who are more likely to benefit from this treatment.

OBJECTIVE

To investigate whether the association of clopidogrel-aspirin with stroke recurrence in patients with minor stroke or high-risk transient ischemic attack (TIA) is modified by the presence of infarct on imaging attributed to the index event (index imaging) among patients enrolled in the POINT Trial.

DESIGN, SETTING, AND PARTICIPANTS

In the POINT randomized clinical trial, patients with high-risk TIA and minor ischemic stroke were enrolled at 269 sites in 10 countries in North America, Europe, Australia, and New Zealand from May 28, 2010, to December 19, 2017. In this post hoc analysis, patients were divided into 2 groups according to whether they had an acute infarct on index imaging. All POINT trial participants with information available on the presence or absence of acute infarct on index imaging were eligible for this study. Univariable Cox regression models evaluated associations between the presence of an infarct on index imaging and subsequent ischemic stroke and evaluated whether the presence of infarct on index imaging modified the association of clopidogrel-aspirin with subsequent ischemic stroke risk. Data were analyzed from July 2020 to May 2021.

EXPOSURES

Presence or absence of acute infarct on index imaging.

MAIN OUTCOMES AND MEASURES

The primary outcome is whether the presence of infarct on index imaging modified the association of clopidogrel-aspirin with subsequent ischemic stroke risk.

RESULTS

Of the 4881 patients enrolled in POINT, 4876 (99.9%) met the inclusion criteria (mean [SD] age, 65 [13] years; 2685 men [55.0%]). A total of 1793 patients (36.8%) had an acute infarct on index imaging. Infarct on index imaging was associated with ischemic stroke during follow-up (hazard ratio [HR], 3.68; 95% CI, 2.73-4.95; P < .001). Clopidogrel-aspirin vs aspirin alone was associated with decreased ischemic stroke risk in patients with an infarct on index imaging (HR, 0.56; 95% CI, 0.41-0.77; P < .001) compared with those without an infarct on index imaging (HR, 1.11; 95% CI, 0.74-1.65; P = .62), with a significant interaction association (P for interaction = .008).

CONCLUSIONS AND RELEVANCE

In this study, the presence of an acute infarct on index imaging was associated with increased risk of recurrent stroke and a more pronounced benefit from clopidogrel-aspirin. Future work should focus on validating these findings before targeting specific patient populations for acute clopidogrel-aspirin treatment.

European Stroke Organisation (ESO) guidelines on management of transient ischaemic attack

The aim of the present European Stroke Organisation Transient Ischaemic Attack (TIA) management guideline document is to provide clinically useful evidence-based recommendations on approaches to triage, investigation and secondary prevention, particularly in the acute phase following TIA. The guidelines were prepared following the Standard Operational Procedure for a European Stroke Organisation guideline document and according to GRADE methodology. As a basic principle, we defined TIA clinically and pragmatically for generalisability as transient neurological symptoms, likely to be due to focal cerebral or ocular ischaemia, which last less than 24 hours. High risk TIA was defined based on clinical features in patients seen early after their event or having other features suggesting a high early risk of stroke (e.g. ABCD2 score of 4 or greater, or weakness or speech disturbance for greater than five minutes, or recurrent events, or significant ipsilateral large artery disease e.g. carotid stenosis, intracranial stenosis). Overall, we strongly recommend using dual antiplatelet treatment with clopidogrel and aspirin short term, in high-risk non-cardioembolic TIA patients, with an ABCD2 score of 4 or greater, as defined in randomised controlled trials (RCTs). We further recommend specialist review within 24 hours after the onset of TIA symptoms. We suggest review in a specialist TIA clinic rather than conventional outpatients, if managed in an outpatient setting. We make a recommendation to use either MRA or CTA in TIA patients for additional confirmation of large artery stenosis of 50% or greater, in order to guide further management, such as clarifying degree of carotid stenosis detected with carotid duplex ultrasound. We make a recommendation against using prediction tools (eg ABCD2 score) alone to identify high risk patients or to make triage and treatment decisions in suspected TIA patients as due to limited sensitivity of the scores, those with score value of 3 or less may include significant numbers of individual patients at risk of recurrent stroke, who require early assessment and treatment. These recommendations aim to emphasise the importance of prompt acute assessment and relevant secondary prevention. There are no data from randomised controlled trials on prediction tool use and optimal imaging strategies in suspected TIA.

Research progress of imaging technologies for ischemic cerebrovascular diseases

Cerebrovascular diseases mainly affect the blood supply of the brain, which has a high demand for oxygen and glucose for the nerve tissues to perform its nerve functions. Ischemic cerebrovascular disease can not only cause stroke, but is also associated with a high incidence of asymptomatic infarction and minimal bleeding that can lead to cognitive and behavioral changes. These changes ultimately manifest as vascular dementia or cognitive impairment. In clinical settings, ischemic cerebrovascular disease can be classified as a transient ischemic attack, reversible ischemic neurological deficit, progressive stroke, complete stroke, marginal infarction, or lacunar infarction. In this review, the research progress of imaging technologies for ischemic cerebrovascular diseases was reviewed, with an aim to provide evidence for clinical practitioners.

Diagnosis and Management of Transient Ischemic Attack and Acute Ischemic Stroke: A Review

IMPORTANCE

Stroke is the fifth leading cause of death and a leading cause of disability in the United States, affecting nearly 800 000 individuals annually.

OBSERVATIONS

Sudden neurologic dysfunction caused by focal brain ischemia with imaging evidence of acute infarction defines acute ischemic stroke (AIS), while an ischemic episode with neurologic deficits but without acute infarction defines transient ischemic attack (TIA). An estimated 7.5% to 17.4% of patients with TIA will have a stroke in the next 3 months. Patients presenting with nondisabling AIS or high-risk TIA (defined as a score ≥4 on the age, blood pressure, clinical symptoms, duration, diabetes [ABCD2] instrument; range, 0-7 [7 indicating worst stroke risk]), who do not have severe carotid stenosis or atrial fibrillation, should receive dual antiplatelet therapy with aspirin and clopidigrel within 24 hours of presentation. Subsequently, combined aspirin and clopidigrel for 3 weeks followed by single antiplatelet therapy reduces stroke risk from 7.8% to 5.2% (hazard ratio, 0.66 [95% CI, 0.56-0.77]). Patients with symptomatic carotid stenosis should receive carotid revascularization and single antiplatelet therapy, and those with atrial fibrillation should receive anticoagulation. In patients presenting with AIS and disabling deficits interfering with activities of daily living, intravenous alteplase improves the likelihood of minimal or no disability by 39% with intravenous recombinant tissue plasminogen activator (IV rtPA) vs 26% with placebo (odds ratio [OR], 1.6 [95% CI, 1.1-2.6]) when administered within 3 hours of presentation and by 35.3% with IV rtPA vs 30.1% with placebo (OR, 1.3 [95% CI, 1.1-1.5]) when administered within 3 to 4.5 hours of presentation. Patients with disabling AIS due to anterior circulation large-vessel occlusions are more likely to be functionally independent when treated with mechanical thrombectomy within 6 hours of presentation vs medical therapy alone (46.0% vs 26.5%; OR, 2.49 [95% CI, 1.76-3.53]) or when treated within 6 to 24 hours after symptom onset if they have a large ratio of ischemic to infarcted tissue on brain magnetic resonance diffusion or computed tomography perfusion imaging (modified Rankin Scale score 0-2: 53% vs 18%; OR, 4.92 [95% CI, 2.87-8.44]).

CONCLUSIONS AND RELEVANCE

Dual antiplatelet therapy initiated within 24 hours of symptom onset and continued for 3 weeks reduces stroke risk in select patients with high-risk TIA and minor stroke. For select patients with disabling AIS, thrombolysis within 4.5 hours and mechanical thrombectomy within 24 hours after symptom onset improves functional outcomes.

Specialized Outpatient Clinic vs Stroke Unit for TIA and Minor Stroke: A Cohort Study

OBJECTIVE

To evaluate the effects of an outpatient clinic setup for minor stroke/TIA using subsequent admission of patients at high risk of recurrent stroke.

METHODS

We performed a cohort study of all patients with suspected minor stroke/TIA seen in an outpatient clinic at Aarhus University Hospital, Denmark, between September 2013 and August 2014. Patients with stroke were compared to historic (same hospital) and contemporary (another comparable hospital) matched, hospitalized controls on nonprioritized outcomes: length of stay, readmissions, care quality (10 process-performance measures), and mortality. Patients with TIA were compared to contemporary matched, hospitalized controls. Following complete diagnostic workup, patients with stroke/TIA were classified into low/high risk of recurrent stroke ≤7 days.

RESULTS

We analyzed 1,076 consecutive patients, of whom 253 (23.5%) were subsequently admitted to the stroke ward. Stroke/TIA was diagnosed in 215/171 patients, respectively. Fifty-six percent (121/215) of the patients with stroke were subsequently admitted to the stroke ward. Comparison with the historic stroke cohort (n = 191) showed a shorter acute hospital stay for the strokes (median 1 vs 3 days; adjusted length of stay ratio 0.49; 95% confidence interval 0.33-0.71). Thirty-day readmission rate was 3.2% vs 11.6% (adjusted hazard ratio 0.23 [0.09-0.59]), and care quality was higher, with a risk ratio of 1.30 (1.15-1.47). The comparison of stroke and TIAs to contemporary controls showed similar results. Only one patient in the low risk category and not admitted experienced stroke within 7 days (0.6%).

CONCLUSIONS

An outpatient clinic setup for patients with minor stroke/TIA yields shorter acute hospital stay, lower readmission rates, and better quality than hospitalization in stroke units.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that a neurovascular specialist-driven outpatient clinic for patients with minor stroke/TIA with the ability of subsequent admission is safe and yields shorter acute hospital stay, lower readmission rates, and better quality than hospitalization in stroke units.

Prospective validation of Canadian TIA Score and comparison with ABCD2 and ABCD2i for subsequent stroke risk after transient ischaemic attack: multicentre prospective cohort study

OBJECTIVE

To validate the previously derived Canadian TIA Score to stratify subsequent stroke risk in a new cohort of emergency department patients with transient ischaemic attack.

DESIGN

Prospective cohort study.

SETTING

13 Canadian emergency departments over five years.

PARTICIPANTS

7607 consecutively enrolled adult patients attending the emergency department with transient ischaemic attack or minor stroke.

MAIN OUTCOME MEASURES

The primary outcome was subsequent stroke or carotid endarterectomy/carotid artery stenting within seven days. The secondary outcome was subsequent stroke within seven days (with or without carotid endarterectomy/carotid artery stenting). Telephone follow-up used the validated Questionnaire for Verifying Stroke Free Status at seven and 90 days. All outcomes were adjudicated by panels of three stroke experts, blinded to the index emergency department visit.

RESULTS

Of the 7607 patients, 108 (1.4%) had a subsequent stroke within seven days, 83 (1.1%) had carotid endarterectomy/carotid artery stenting within seven days, and nine had both. The Canadian TIA Score stratified the risk of stroke, carotid endarterectomy/carotid artery stenting, or both within seven days as low (risk ≤0.5%; interval likelihood ratio 0.20, 95% confidence interval 0.09 to 0.44), medium (risk 2.3%; interval likelihood ratio 0.94, 0.85 to 1.04), and high (risk 5.9% interval likelihood ratio 2.56, 2.02 to 3.25) more accurately (area under the curve 0.70, 95% confidence interval 0.66 to 0.73) than did the ABCD2 (0.60, 0.55 to 0.64) or ABCD2i (0.64, 0.59 to 0.68). Results were similar for subsequent stroke regardless of carotid endarterectomy/carotid artery stenting within seven days.

CONCLUSION

The Canadian TIA Score stratifies patients' seven day risk for stroke, with or without carotid endarterectomy/carotid artery stenting, and is now ready for clinical use. Incorporating this validated risk estimate into management plans should improve early decision making at the index emergency visit regarding benefits of hospital admission, timing of investigations, and prioritisation of specialist referral.

The time course of acute Percheron artery ischemic coma on imaging: A retrospective cohort study

We were to investigate the time course of lesions for awakening in acute Percheron artery ischemic coma (PAIC), which was previously unknown. Patients who had newly identified acute PAIC events in 2012-2015 and had not received thrombolytic therapy were enrolled retrospectively. The time course of lesions in PAIC was investigated by diffusion-weighted imaging (DWI). Ninety-three patients met the inclusion criteria, of whom 63 and 30 had transient PAIC and persistent PAIC, respectively. The time course of awakening events in persistent PAIC decreased over time, with large lesions in the bilateral paramedian thalamus/ rostral midbrain on DWI almost in all patients who was either plus or minus a "top of basilar artery" strokes. Whereas awakening events in transient PAIC increased over time, with small or lacunar lesions in the unilateral or bilateral thalamus/rostral midbrain about in 30.2 % cases, and the rest in naturally recanalization of infarcts or TIA. Lesion volumes were larger for persistent PAIC than for transient PAIC (median, 2.4 cm³ vs. 0.03 cm³, P < 0.0001). In Cox hazards ratio (HR) analysis, a lower GCS score was associated with mortality (HR, 5.5; 95 % confidence interval [CI],1.427-21.45). Multivaliate analysis shown that the predictors of higher risk of persistent PAIC were only increased NIHSS scores (HR,1.3; 95 % CI,1.109-1.640) and large lesions in bilateral thalamus/rostral midbrain (HR,15.0; 95 % CI,1.440-58.13). The time course of acute PAIC included transient and persistent. Most persistent PAIC was associated with large lesions in bilateral paramedian thalamus/ rostral midbrain, and with high mortality.

Rapid Sequence MRI Protocol in the Evaluation of Pediatric Brain Attacks

BACKGROUND

The objective of our study was to evaluate the clinical utility of rapid sequence magnetic resonance imaging (MRI) utilizing diffusion-weighted imaging and fluid-attenuated inversion recovery sequences in children with acute ischemic strokes and nonstroke brain attacks.

METHODS

We performed a retrospective chart review of patients aged one month to 25 years for whom a pediatric stroke clinical pathway was activated. Diffusion-weighted imaging and fluid-attenuated inversion recovery were obtained followed by a complete MRI. Imaging was interpreted by a pediatric radiologist and the study neurologist. We collected information regarding patient demographics, neuroimaging results, and final diagnosis.

RESULTS

The Pediatric Stroke Clinical Pathway was activated for 59 patients of whom 52 were included for analysis. The majority of patients were female (n = 29, 55.8%) and African American (n = 32, 61.5%), with a median age of 12 years (interquartile range 9, 16). Six patients had an ischemic stroke. Seizures, migraines, and psychosomatic disorders (each with n = 7; 13.5%) were the most common nonstroke diagnoses. Diffusion-weighted imaging was more sensitive (100% [55.0% to 100%] versus 80 % [32% to 99%]) and specific (73.9% [68% to 74%] versus 37.2% [32% to 39%]) compared with fluid-attenuated inversion recovery in identification of an ischemic stroke. However, fluid-attenuated inversion recovery was useful in the identification of inflammatory and metabolic disorders.

CONCLUSION

Rapid sequence MRI can be utilized as a screening imaging modality in children with suspected brain attacks in cases where there may be delays in obtaining full sequence brain imaging.

Clinical Risk Score for Predicting Recurrence Following a Cerebral Ischemic Event

Introduction: Recurrent stroke has a higher rate of death and disability. A number of risk scores have been developed to predict short-term and long-term risk of stroke following an initial episode of stroke or transient ischemic attack (TIA) with limited clinical utilities. In this paper, we review different risk score models and discuss their validity and clinical utilities.

Methods: The PubMed bibliographic database was searched for original research articles on the various risk scores for risk of stroke following an initial episode of stroke or TIA. The validation of the models was evaluated by examining the internal and external validation process as well as statistical methodology, the study power, as well as the accuracy and metrics such as sensitivity and specificity.

Results: Different risk score models have been derived from different study populations. Validation studies for these risk scores have produced conflicting results. Currently, ABCD² score with diffusion weighted imaging (DWI) and Recurrence Risk Estimator at 90 days (RRE-90) are the two acceptable models for short-term risk prediction whereas Essen Stroke Risk Score (ESRS) and Stroke Prognosis Instrument-II (SPI-II) can be useful for prediction of long-term risk.

Conclusion: The clinical risk scores that currently exist for predicting short-term and long-term risk of recurrent cerebral ischemia are limited in their performance and clinical utilities. There is a need for a better predictive tool which can overcome the limitations of current predictive models. Application of machine learning methods in combination with electronic health records may provide platform for development of new-generation predictive tools.

External Validation of the Diagnosis of TIA (DOT) Score for Identification of TIA in a Chinese Population

Background: Recently, the [diagnosis of transient ischemic attack (TIA), DOT] score has been recognized to be a new tool for non-specialists to diagnose TIA more accurately with the sensitivity and specificity being 89 and 76%, respectively. However, the DOT score has not yet been validated externally in patients with TIA in China.

Methods: We retrospectively enrolled 500 consecutive patients with transient neurological symptoms, who were admitted to the Department of Neurology, Beijing Chaoyang Hospital and underwent magnetic resonance imaging (MRI) between Jan 2016 and Dec 2018. Patients with transient neurological symptoms were divided into two subgroups: TIA mimic group (N = 140, 28%) and definite cerebrovascular events group including tissue-based TIA (DWI negative, N = 252, 50.4%) and minor stroke (DWI positive, N = 108, 21.6%). The demographic data, clinical characteristics, laboratory findings, and scores of Dawson and DOT were compared between the two groups.

Results: A total of 500 patients with transient neurological symptoms (mean age, 61.1 ± 12.8) were enrolled and 70% (N = 350) were male. Comparing with TIA mimic groups, patients with cerebrovascular events group were more likely to have higher diastolic blood pressure, uric acid and homocysteine, more motor weakness and speech abnormalities, and also scored higher using the Dawson and DOT. The area under the curve (AUC) was 0.728 for DOT, with a sensitivity of 70.3% and specificity of 62.9%, respectively.

Conclusion: In patients with transient neurological symptoms, our findings showed that the DOT score had relatively good calibration and discrimination to identify of TIA in a Chinese Population. As a novel tool of TIA identification, further validations are needed in multiple centers with larger samples in China.

Incidence and Predictors of Acute Ischemic Lesions on Brain Magnetic Resonance Imaging in Patients With a Clinical Diagnosis of Transient Ischemic Attack in China

Background: The associations between the clinical characteristics and diffusion-weighted imaging (DWI) positivity in patients with a clinical diagnosis of transient ischemic attack (TIA) are still poorly understood. The purpose of our study was to determine the incidence of TIA related acute infarction by DWI, and to determine the underlying predictors of DWI positivity in TIA patients.

Methods: Between Jan 2017 and Dec 2018, we retrospectively enrolled 430 patients with a clinical diagnosis of TIA who underwent DWI. Patients were divided into those with acute ischemic lesions (DWI positive group) and those without (DWI negative group). The clinical characteristics, laboratory data, and imaging parameters were compared between the two groups.

Results: A total of 430 time-based TIA patients (mean age, 61.4 ± 13.0) were enrolled in this study. About 126 (29.3%) of TIA patients had a DWI positive lesion in our series. Comparing TIA patients with positive DWI to those with negative DWI, acute lesions were more likely to be more male, have higher hyperlipidemia and a smoking history, more speech abnormalities and increased motor weakness; and higher systolic and diastolic blood pressure, homocysteine, fasting blood glucose, and the scores of ABCD2, ABCD3, ABCD3-I, and Dawson. Several independent predictors of DWI positivity were identified with logistic regression analysis: motor weakness (odds ratio 4.861, P = 0.021), speech abnormalities (odds ratio 4.029, P = 0.024), and ABCD3-I (odds ratio 13.141, P = 0.001). ABCD3-I showed the greatest area under the ROC curve, with a sensitivity of 85.7% and specificity of 72.4%.

Conclusion: In patients with a clinical diagnosis of TIA, 29.3% demonstrated acute DWI lesions on brain magnetic resonance imaging (MRI). They were associated with motor weakness, speech abnormalities and higher ABCD3-I score at admission.

Clinical diagnosis of TIA or minor stroke and prognosis in patients with neurological symptoms: A rapid access clinic cohort

BACKGROUND

The long-term risk of stroke or myocardial infarction (MI) in patients with minor neurological symptoms who are not clinically diagnosed with transient ischaemic attack (TIA) or minor stroke is uncertain.

METHODS

We used data from a rapid access clinic for patients with suspected TIA or minor stroke and follow-up from four overlapping data sources for a diagnosis of ischaemic or haemorrhagic stroke, MI, major haemorrhage and death. We identified patients with and without a clinical diagnosis of TIA or minor stroke. We estimated hazard ratios of stroke, MI, major haemorrhage and death in early and late time periods.

RESULTS

5,997 patients were seen from 2005-2013, who were diagnosed with TIA or minor stroke (n = 3604, 60%) or with other diagnoses (n = 2392, 40%). By 5 years the proportion of patients who had a subsequent ischaemic stroke or MI, in patients with a clinical diagnosis of minor stroke or TIA was 19% [95% confidence interval (CI): 17-20%], and in patients with other diagnoses was 10% (95%CI: 8-15%). Patients with clinical diagnosis of TIA or minor stroke had three times the hazard of stroke or MI compared to patients with other diagnoses [hazard ratio (HR)2.83 95%CI:2.13-3.76, adjusted age and sex] by 90 days post-event; however from 90 days to end of follow up, this difference was attenuated (HR 1.52, 95%CI:1.25-1.86). Older patients and those who had a history of vascular disease had a high risk of stroke or MI, whether or not they were diagnosed with minor stroke or TIA.

CONCLUSIONS

Careful attention to vascular risk factors in patients presenting with transient or minor neurological symptoms not thought to be due to stroke or TIA is justified, particularly those who are older or have a history of vascular disease.

Early risk assessment of circulating endothelial progenitor cells and plasma stromal cell-derived factor-1 for nondisabling ischemic cerebrovascular events

Background

Endothelial progenitor cells (EPCs) play an important role in ischemic stroke. However, there are few studies on the relationship between EPC and nondisabling ischemic cerebrovascular events. Our aim was to investigate the association of EPCs and SDF-1 (serum stromal cell-derived factor-1) with NICE (nondisabling ischemic cerebrovascular events).

Methods

TIA (transient ischemic attack) and minor stroke patients (153 in total) who had an onset of symptoms within 1 day were consecutively collected. 83 of the patients were categorized into the HR-NICE (high-risk nondisabling ischemic cerebrovascular event) group, and 70 of the patients were in the NHR-NICE (non-high-risk nondisabling ischemic cerebrovascular events) group. Adopted FCM (flow cytometry) was used to measure EPCs, taking double-positive CD34/KDR as EPCs. ELISA was used to measure the concentrations of serum SDF-1 and VEGF (vascular endothelial growth factor). By the sequence of admission time, 15 patients were selected separately from the HR-NICE group and NHR-NICE group, and another 15 healthy volunteers were chosen as the NC (Normal Control) group. The MTT method was used to measure the proliferation of EPCs of peripheral blood in all groups, and the Boyden chamber was used to measure the migration of EPCs.

Results

Compared with the NHR-NICE group, the HR-NICE group was older and contained more patients with hypertension and diabetes. Triglyceride, total cholesterol, and low-density lipoprotein in the HR-NICE group were also higher. For factors such as smoking, BMI (body mass index), and HCY (homocysteine), there were no significant differences (P > 0.05). Circulating EPCs, SDF-1, and VEGF in the NHR-NICE group were all higher. According to the multifactor regression analysis, age, hypertension, diabetes, total cholesterol, EPCs, and SDF-1 are independent risk factors for HR-NICE. For EPCs of 48-h isolated cultures, proliferation and migration were observed to be weakened compared with those of the NC group (P < 0.05). EPCs in HR-NICE group had lower proliferation and migration than those in NHR-NICE group (P < 0.01).

Conclusions

For TIA and minor stroke patients, circulating EPCs and serum SDF-1 concentrations can be used to prognose HR-NICE. Factors that lead to high-risk NICE might be relevant to the decrease in proliferation and migration of circulating EPCs.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Non-invasive evaluation of cerebral perfusion in patients with transient ischemic attack: an fMRI study

Detection of hypoperfused tissue due to the ischemia is considered to be important in understanding the cerebral perfusion status and may be helpful in guiding therapeutic decisions for patients with transient ischemic attack (TIA). We hypothesized that the combination of two non-invasive fMRI techniques: resting-state BOLD-fMRI time-shift analysis (TSA) approach and 3D ASL, could detect the cerebral hemodynamic status in TIA patients noninvasively. From April 2015 to June 2016, 51 TIA patients were recruited in this study. We calculated the time delay between the resting-state BOLD signal at each voxel and the whole-brain signal using TSA approach and compared the results to CBF map derived from ASL. Out of the 51 patients, 24 patients with normal arrival time and CBF were in Stage 0; 14 patients who showed delayed arrival time and normal CBF which indicated elevated CBV were in Stage I; the other 13 patients who had both delayed arrival time and decreased CBF were in Stage II, the group average spatial overlap, i.e., Dice coefficient, of the two measurements was 0.55. Four patients in Stage 0 (17.4%), three patients in Stage I (23.1%) and five patients in Stage II (45.5%) suffered ischemic stroke or TIA symptoms in 1 year after MRI scan. The patients in Stage II was at highest risk of subsequent events when compared to other two stages. The combination of resting-state BOLD-fMRI and ASL hold the potential to noninvasively identify the hemodynamic status in TIA patients and help predict the risk of subsequent events.

Can I Send This Patient with Stroke Home? Strategies Managing Transient Ischemic Attack and Minor Stroke in the Emergency Department

BACKGROUND

While transient ischemic attack and minor stroke (TIAMS) are common conditions evaluated in the emergency department (ED), there is controversy regarding the most effective and efficient strategies for managing them in the ED. Some patients are discharged after evaluation in the ED and cared for in the outpatient setting, while others remain in an observation unit without being admitted or discharged, and others experience prolonged and potentially costly inpatient admissions.

OBJECTIVE OF THE REVIEW

The goal of this clinical review was to summarize and present recommendations regarding the disposition of TIAMS patients in the ED (e.g., admission vs. discharge).

DISCUSSION

An estimated 250,000 to 300,000 TIA events occur each year in the United States, with an estimated near-term risk of subsequent stroke ranging from 3.5% to 10% at 2 days, rising to 17% by 90 days. While popular and easy to use, reliance solely on risk-stratification tools, such as the ABCD2, should not be used to determine whether TIAMS patients can be discharged safely. Additional vascular imaging and advanced brain imaging may improve prediction of short-term neurologic risk. We also review various disposition strategies (e.g., inpatient vs. outpatient/ED observation units) with regard to their association with neurologic outcomes, such as 30-day or 90-day stroke recurrence or new stroke, in addition to other outcomes, such as hospital length of stay and health care costs.

CONCLUSIONS

Discharge from the ED for rapid outpatient follow-up may be a safe and effective strategy for some forms of minor stroke without disabling deficit and TIA patients after careful evaluation and initial ED workup. Future research on such strategies has the potential to improve neurologic and overall patient outcomes and reduce hospital costs and ED length of stay.

New Standards of Care in Ischemic Stroke

BACKGROUND

Ischemic arterial strokes of the ophthalmic artery and its branches and posterior cerebral artery are common causes of visual disability. Etiologies of stroke affecting the retina, optic nerve, optic radiation, and visual cortex overlap with other types of ischemic strokes. Stenosis of the internal carotid is the most common cause of central retinal artery occlusion (CRAO). One-fourth of patients with CRAO have cerebral strokes. We report recent developments in the acute treatment and secondary prevention of ischemic stroke of relevance to clinicians who encounter patients with acute vision loss.

EVIDENCE ACQUISITION

A search of Pubmed and practice guidelines over the past 5 years was performed, with a focus on significant changes in treatment and prevention of ischemic stroke.

RESULTS

Recent randomized controlled trials provide Level I evidence for the use of endovascular therapy with current stent retriever devices for patients with large vessel anterior circulation occlusions within 6 hours of presentation. Number needed to treat to achieve one additional patient with an independent functional outcome was in the range of 3-7, and benefit was additive to that of intravenous tissue plasminogen activator alone. Paroxysmal atrial fibrillation (AF) is a major cause of cryptogenic stroke with incidence expected to rise with the aging population. Since 2014, prolonged 30-day cardiac monitoring has been recommended as a part of transient ischemic attack and stroke workup in patients with cryptogenic stroke. Even longer term monitoring of 6 months to 1 year with external and implantable loop recorders improves rates of diagnosing AF. First available in 2010, the novel anticoagulants-dabigatran, apixaban, rivaroxaban, and edoxaban-have been compared with warfarin in the prevention of stroke in patients with nonvalvular AF. Apixaban demonstrated superiority in safety and efficacy, with the novel anticoagulants as a group having favorable risk-benefit profile at higher dosages compared with standard warfarin therapy.

CONCLUSIONS

Endovascular therapy is now standard of care for eligible patients with anterior large vessel occlusions. Prolonged cardiac monitoring is recommended for patients with cryptogenic stroke. The novel anticoagulants are an alternative to warfarin in patients with AF.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Transient Ischemic Attack in Pediatric Patients With Moyamoya Disease: Clinical Features, Natural History, and Predictors of Stroke

BACKGROUND

Despite being the most common presentation in children with moyamoya, transient ischemic attack (TIA) in children has rarely been described. The aim of this study is to describe the clinical characteristics of TIAs in children with moyamoya and explore the risk factors for stroke after TIA.

METHODS

We reviewed 696 consecutive patients with moyamoya vasculopathy (155 pediatric patients and 541 adults) admitted to our hospital from 2009 to 2015 to identify pediatric patients with moyamoya with an initial presentation of TIA. We defined recurrent TIAs that involve more types of symptoms or symptom extensions as symptom progression. The risk factors for subsequent stroke were analyzed using time-to-event analyses.

RESULTS

We identified 60 pediatric patients with moyamoya who had presented with TIA (initial presentation age, 10.0 ± 3.5 years). Motor weakness (n = 51 [85%]) was the most common initial presentation. During follow-up, 55 patients (91.7%) had recurrent TIAs and 14 (23.3%) had subsequent strokes. We identified female gender (hazard ratio, 5.08; 95% confidence interval, 1.40-18.47; P = 0.01), Suzuki grade greater than 3 (hazard ratio, 4.01; 95% confidence interval, 1.16-13.82; P = 0.03), and symptom progression (hazard ratio, 5.31; 95% confidence interval, 1.65-17.14; P = 0.01) as independent predictors of future stroke events.

CONCLUSIONS

Transient ischemic attacks have a relatively high recurrence rate in children with moyamoya and are associated with subsequent stroke. We identified the female sex, Suzuki grade greater than  3, and symptom progression as independent predictors of future strokes.

Differences in Characteristics and Outcomes Between Asian and Non-Asian Patients in the TIAregistry.org

Background and Purpose—

This study provides the contemporary causes and prognosis of transient ischemic attack (TIA) and minor stroke in Asians and the direct comparisons with non-Asians.

Methods—

The TIAregistry.org enrolled 4789 patients (1149 Asians and 3640 non-Asians) with a TIA or minor ischemic stroke within 7 days of onset. Every participating facility had systems dedicated to urgent intervention of TIA/stroke patients by specialists. The primary outcome was a composite of cardiovascular death, nonfatal stroke, and nonfatal acute coronary syndrome.

Results—

Approximately 80% of patients were evaluated within 24 hours of symptom onset. At 1 year, there were no differences in the rates of composite cardiovascular events (6.8% versus 6.0%; P =0.38) and stroke (6.0% versus 4.8%; P =0.11) between Asians and non-Asians. Asians had a lower risk of cerebrovascular disease (stroke or TIA) than non-Asians (adjusted hazard ratio, 0.79; 95% confidence interval, 0.63–0.98; P =0.03); the difference was primarily driven by a lower rate of TIA in Asians (4.2% versus 8.3%; P <0.001). Moderately severe bleeding was more frequent in Asians (0.8% versus 0.3%; P =0.02). In multivariable analysis, multiple acute infarcts ( P =0.005) and alcohol consumption ( P =0.02) were independent predictors of stroke recurrence in Asians, whereas intracranial stenosis ( P <0.001), ABCD 2 score ( P <0.001), atrial fibrillation ( P =0.008), extracranial stenosis ( P =0.03), and previous stroke or TIA ( P =0.03) were independent predictors in non-Asians.

Conclusions—

The short-term stroke risk after a TIA or minor stroke was lower than expected when urgent evidence-based care was delivered, irrespective of race/ethnicity or region. However, the predictors of stroke were different for Asians and non-Asians.

Imaging Parameters and Recurrent Cerebrovascular Events in Patients With Minor Stroke or Transient Ischemic Attack

IMPORTANCE

Neurological worsening and recurrent stroke contribute substantially to morbidity associated with transient ischemic attacks and strokes (TIA-S).

OBJECTIVE

To determine predictors of early recurrent cerebrovascular events (RCVEs) among patients with TIA-S and National Institutes of Health Stroke Scale scores of 0 to 3.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted at 2 tertiary care centers (Columbia University Medical Center, New York, New York, and Tulane University Medical Center, New Orleans, Louisiana) between January 1, 2010, and December 31, 2014. All patients with neurologist-diagnosed TIA-S with a National Institutes of Health Stroke Scale score of 0 to 3 who presented to the emergency department were included.

MAIN OUTCOMES AND MEASURES

The primary outcome (adjudicated by 3 vascular neurologists) was RCVE: neurological deterioration in the absence of a medical explanation or recurrent TIA-S during hospitalization.

RESULTS

Of the 1258 total patients, 1187 had no RCVEs and 71 had RCVEs; of this group, 750 patients (63.2%) and 39 patients (54.9%), respectively, were aged 60 years or older. There were 505 patients with TIA-S at Columbia University; 31 (6.1%) had RCVEs (15 patients had neurological deterioration only, 11 had recurrent TIA-S only, and 5 had both). The validation cohort at Tulane University consisted of 753 patients; 40 (5.3%) had RCVEs (24 patients had neurological deterioration only and 16 had both). Predictors of RCVE in multivariate models in both cohorts were infarct on neuroimaging (computed tomographic scan or diffusion-weighted imaging sequences on magnetic resonance imaging) (Columbia University: not applicable and Tulane University: odds ratio, 1.75; 95% CI, 0.82-3.74; P = .15) and large-vessel disease etiology (Columbia University: odds ratio, 6.69; 95% CI, 3.10-14.50 and Tulane University: odds ratio, 8.13; 95% CI, 3.86-17.12; P < .001). There was an increase in the percentage of patients with RCVEs when both predictors were present. When neither predictor was present, the rate of RCVE was extremely low (up to 2%). Patients with RCVEs were less likely to be discharged home in both cohorts.

CONCLUSIONS AND RELEVANCE

In patients with minor stroke, vessel imaging and perhaps neuroimaging parameters, but not clinical scores, were associated with RCVEs in 2 independent data sets. Prospective studies are needed to validate these predictors.

Acute Stroke and Transient Ischemic Attack in the Outpatient Clinic

Ischemic stroke is cause of substantial death and disability in the United States. Transient ischemic attack, a precursor to ischemic stroke, conveys a high risk of recurrent stroke within 90 days from event. These conditions are highly preventable and treatable. The cause is heterogenous and includes atherothrombosis, cardioembolism, lacunar disease, or cryptogenic, and some uncommon causes, such as arterial dissection and prothrombotic states. The emergent evaluation includes establishing time of onset, vital signs, glucose level, and severity of the deficit.

Pathways for Neuroimaging of Childhood Stroke

BACKGROUND

The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for children who present with symptoms that could be caused by stroke.

METHODS

The Writing Group members participated in one or more pediatric stroke neuroimaging symposiums hosted by the Stroke Imaging Laboratory for Children housed at the Hospital for Sick Children in Toronto, Ontario, Canada. Through collaboration, literature review, and discussion among child neurologists with expertise diagnosing and treating childhood stroke and pediatric neuroradiologists and neuroradiologists with expertise in pediatric neurovascular disease, suggested imaging protocols are presented for children with suspected stroke syndromes including arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke.

RESULTS

This article presents information about the epidemiology and classification of childhood stroke with definitions based on the National Institutes of Health Common Data Elements. The role of imaging for the diagnosis of childhood stroke is examined in depth, with separate sections for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke. Abbreviated neuroimaging protocols for rapid diagnosis are discussed. The Writing Group provides suggestions for optimal neuroimaging investigation of various stroke types in the acute setting and suggestions for follow-up neuroimaging. Advanced sequences such as diffusion tensor imaging, perfusion imaging, and vessel wall imaging are also discussed.

CONCLUSIONS

This article provides protocols for the imaging of children who present with suspected stroke.

Validation and comparison of imaging-based scores for prediction of early stroke risk after transient ischaemic attack: a pooled analysis of individual-patient data from cohort studies

BACKGROUND

Identification of patients at highest risk of early stroke after transient ischaemic attack has been improved with imaging based scores. We aimed to compare the validity and prognostic utility of imaging-based stroke risk scores in patients after transient ischaemic attack.

METHODS

We did a pooled analysis of published and unpublished individual-patient data from 16 cohort studies of transient ischaemic attack done in Asia, Europe, and the USA, with early brain and vascular imaging and follow up. All patients were assessed by stroke specialists in hospital settings as inpatients, in emergency departments, or in transient ischaemic attack clinics. Inclusion criteria were stroke-specialist confirmed transient ischaemic attack, age of 18 years or older, and MRI done within 7 days of index transient ischaemic attack and before stroke recurrence. Multivariable logistic regression was done to analyse the predictive utility of abnormal diffusion-weighted MRI, carotid stenosis, and transient ischaemic attack within 1 week of index transient ischaemic attack (dual transient ischaemic attack) after adjusting for ABCD2 score. We compared the prognostic utility of the ABCD2, ABCD2-I, and ABCD3-I scores using discrimination, calibration, and risk reclassification.

FINDINGS

In 2176 patients from 16 cohort studies done between 2005 and 2015, after adjusting for ABCD2 score, positive diffusion-weighted imaging (odds ratio [OR] 3·8, 95% CI 2·1-7·0), dual transient ischaemic attack (OR 3·3, 95% CI 1·8-5·8), and ipsilateral carotid stenosis (OR 4·7, 95% CI 2·6-8·6) were associated with 7 day stroke after index transient ischaemic attack (p<0·001 for all). 7 day stroke risk increased with increasing ABCD2-I and ABCD3-I scores (both p<0·001). Discrimination to identify early stroke risk was improved for ABCD2-I versus ABCD2 (2 day c statistic 0·74 vs 0·64; p=0·006). However, discrimination was further improved by ABCD3-I compared with ABCD2 (2 day c statistic 0·84 vs 0·64; p<0·001) and ABCD2-I (c statistic 0·84 vs 0·74; p<0·001). Early stroke risk reclassification was improved by ABCD3-I compared with ABCD2-I score (clinical net reclassification improvement 33% at 2 days).

INTERPRETATION

Although ABCD2-I and ABCD3-I showed validity, the ABCD3-I score reliably identified highest-risk patients at highest risk of a stroke after transient ischaemic attack with improved risk prediction compared with ABCD2-I. Transient ischaemic attack management guided by ABCD3-I with immediate stroke-specialist assessment, urgent MRI, and vascular imaging should now be considered, with monitoring of safety and cost-effectiveness.

FUNDING

Health Research Board of Ireland, Irish Heart Foundation, Irish Health Service Executive, Irish National Lottery, National Medical Research Council of Singapore, Swiss National Science Foundation, Bangerter-Rhyner Foundation, Swiss National Science Foundation, Swisslife Jubiläumsstiftung for Medical Research, Swiss Neurological Society, Fondazione Dr Ettore Balli (Switzerland), Clinical Trial Unit of University of Bern, South Korea's Ministry for Health, Welfare, and Family Affairs, UK Wellcome Trust, Wolfson Foundation, UK Stroke Association, British Heart Foundation, Dunhill Medical Trust, National Institute of Health Research (NIHR), Medical Research Council, and the NIHR Oxford Biomedical Research Centre.

One-Year Risk of Stroke after Transient Ischemic Attack or Minor Stroke

BACKGROUND

Previous studies conducted between 1997 and 2003 estimated that the risk of stroke or an acute coronary syndrome was 12 to 20% during the first 3 months after a transient ischemic attack (TIA) or minor stroke. The TIAregistry.org project was designed to describe the contemporary profile, etiologic factors, and outcomes in patients with a TIA or minor ischemic stroke who receive care in health systems that now offer urgent evaluation by stroke specialists.

METHODS

We recruited patients who had had a TIA or minor stroke within the previous 7 days. Sites were selected if they had systems dedicated to urgent evaluation of patients with TIA. We estimated the 1-year risk of stroke and of the composite outcome of stroke, an acute coronary syndrome, or death from cardiovascular causes. We also examined the association of the ABCD(2) score for the risk of stroke (range, 0 [lowest risk] to 7 [highest risk]), findings on brain imaging, and cause of TIA or minor stroke with the risk of recurrent stroke over a period of 1 year.

RESULTS

From 2009 through 2011, we enrolled 4789 patients at 61 sites in 21 countries. A total of 78.4% of the patients were evaluated by stroke specialists within 24 hours after symptom onset. A total of 33.4% of the patients had an acute brain infarction, 23.2% had at least one extracranial or intracranial stenosis of 50% or more, and 10.4% had atrial fibrillation. The Kaplan-Meier estimate of the 1-year event rate of the composite cardiovascular outcome was 6.2% (95% confidence interval, 5.5 to 7.0). Kaplan-Meier estimates of the stroke rate at days 2, 7, 30, 90, and 365 were 1.5%, 2.1%, 2.8%, 3.7%, and 5.1%, respectively. In multivariable analyses, multiple infarctions on brain imaging, large-artery atherosclerosis, and an ABCD(2) score of 6 or 7 were each associated with more than a doubling of the risk of stroke.

CONCLUSIONS

We observed a lower risk of cardiovascular events after TIA than previously reported. The ABCD(2) score, findings on brain imaging, and status with respect to large-artery atherosclerosis helped stratify the risk of recurrent stroke within 1 year after a TIA or minor stroke. (Funded by Sanofi and Bristol-Myers Squibb.).

Tissue-Negative Transient Ischemic Attack: Is There a Role for Perfusion MRI?

OBJECTIVE

Approximately 60% of patients with a clinical transient ischemic attack (TIA) do not have DWI evidence of cerebral ischemia. The purpose of this study was to assess the added diagnostic value of perfusion MRI in the evaluation of patients with TIA who have normal DWI findings.

MATERIALS AND METHODS

The inclusion criteria for this retrospective study were clinical presentation of TIA at admission with a discharge diagnosis of TIA confirmed by a stroke neurologist, MRI including both DWI and perfusion-weighted imaging within 48 hours of symptom onset, and no DWI lesion. Cerebral blood flow (CBF) and time to maximum of the residue function (Tmax) maps were evaluated independently by two observers. Multivariate analysis was used to assess perfusion findings; clinical variables; age, blood pressure, clinical symptoms, diabetes (ABCD2) score; duration of TIA; and time between MRI and onset and resolution of symptoms.

RESULTS

Fifty-two patients (33 women, 19 men; age range, 20-95 years) met the inclusion criteria. A regional perfusion abnormality was identified on either Tmax or CBF maps of 12 of 52 (23%) patients. Seven (58%) of the patients with perfusion abnormalities had hypoperfused lesions best detected on Tmax maps; the other five had hyperperfusion best detected on CBF maps. In 11 of 12 (92%) patients with abnormal perfusion MRI findings, the regional perfusion deficit correlated with the initial neurologic deficits. Multivariable analysis revealed no significant difference in demographics, ABCD2 scores, or presentation characteristics between patients with and those without perfusion abnormalities.

CONCLUSION

Perfusion MRI that includes Tmax and CBF parametric maps adds diagnostic value by depicting regions with delayed perfusion or postischemic hyperperfusion in approximately one-fourth of TIA patients who have normal DWI findings.

Implementation of a Community-Based Triage for Patients with Suspected Transient Ischemic Attack or Minor Stroke Study: A Prospective Multicenter Observational Study

BACKGROUND

Japan has the highest number of magnetic resonance imaging units in the world, and citizens can freely choose medical care at any hospital or clinic. We aimed to investigate the triage of patients with suspected transient ischemic attack (TIA) or minor stroke in this unique Japanese healthcare system.

METHODS

In this cohort study, patients with suspected TIA or minor stroke (National Institutes of Health Stroke Scale score <4) within 7 days after onset were prospectively enrolled and followed for 1 year. The high-risk group was defined as having at least one of the following 5 items at the initial visit: (1) atrial fibrillation, (2) carotid stenosis, (3) crescendo TIA, (4) definite focal brain symptoms, or (5) ABCD2 score of 4 or higher. After the initial assessment, the patients were diagnosed as having acute ischemic cerebrovascular syndrome (AICS) or stroke mimic. AICS was classified into 3 categories including definite, probable, and possible AICS, based on evidence of neurological deficits and brain infarction on the imaging study.

RESULTS

A total of 353 patients were enrolled and 89.8% of the patients were examined by diffusion-weighted imaging at the initial visit. Kaplan-Meier analyses demonstrated a statistically significant difference in subsequent stroke risk when the patients were triaged by the ABCD2 score (P = .031), 5-item high-risk categorization (P = .032), or AICS classification (P = .001).

CONCLUSIONS

This study demonstrates that hospitals and clinics with imaging facilities play a major role in triage and that the ABCD2 score, 5-item high-risk categorization, and AICS classification are useful as triage tools for patients with suspected TIA or minor stroke.

Transient and persistent symptoms in patients with lacunar infarction: results from a prospective cohort study

Background

The transient symptoms with lacunar infarction (TSI) and persistent symptoms with lacunar infarction (PSI) are the most common forms of symptomatic lacunar infarction (LI). The aim of this study was to compare the differences in TSI and PSI of symptomatic LI.

Methods

A prospective cohort study was conducted in the neurologic outpatients of the tertiary teaching hospital in Northern China between February 2011 and February 2012. The TSI and PSI in participants aged 35 years or over were assessed. Patients were followed up and their outcomes were compared.

Results

Of the 453 symptomatic outpatients, 251 patients with LI were diagnosed by magnetic resonance imaging. Approximately 77.3% (194/251) of the patients with LI at this time had TSI. and the remaining 23.7% had PSI. After the adjusted odds ratios, only middle age (risk ratio [RR], 1.1; 95% confidence interval [CI], 1.157–1.189), lower National Institutes of Health Stroke Scale score (RR, 20.6; 95% CI, 6.705–13.31), smaller lacunae on brain images (RR, 2.9; 95% CI, 1.960–4.245), and LI frequently in the anterior circulation territory (RR, 0.2; 95% CI, 0.079–0.721) were independently associated with TSI. During a mean follow-up of 6 months, survival rate was significantly higher among patients with TSI than among those with PSI (log rank, 6.9; P=0.010); estimated unadjusted incidence of vascular subsequent events (30.9% vs 54.4%, P=0.001) was significantly lower in TSI than in PSI.

Conclusion

The TSI has a higher prevalence and is associated with a lower risk of vascular subsequent events and death than PSI. The implications of these findings for TSI and PSI may require different interventions.

Predictors of Stroke After Transient Ischemic Attack in Children

BACKGROUND AND PURPOSE

Transient ischemic attack (TIA) in children has received far less attention compared with TIA in adults. The risk factors of stroke after TIA in children are relatively unknown. We aimed to determine the percentage of children who have stroke after TIA and the risk factors associated with stroke after TIA.

METHODS

We searched the medical records at Boston Children's Hospital for the year 2010 to find children who were evaluated for TIA to determine associated risk factors of stroke after TIA. We included children who were evaluated in 2009 through 2010 for TIA and had magnetic resonance imaging. We examined follow-up imaging through August 2014 for subsequent stroke. Logistic regression was used to calculate odds ratios for factors in our cohort who are associated with stroke after presentation with TIA.

RESULTS

We identified 63 children who experienced a TIA. The mean time of imaging follow-up was 4.5 years after TIA presentation. Of the 63 children, 10 (16%) developed radiological evidence of ischemic cerebral injury within the follow-up period. Four of the 10 (6%) demonstrated diffusion abnormalities on magnetic resonance imaging at TIA presentation, whereas 8 (13%) had a stroke after their TIA. Arteriopathy, female sex, and autoimmune disorders were significantly associated with stroke after TIA.

CONCLUSIONS

In our cohort of children, stroke occurred after TIA at a rate similar to that seen in adults, but the risk factors for stroke after TIA in children are different.

Validation of the RRE-90 Scale to Predict Stroke Risk after Transient Symptoms with Infarction: A Prospective Cohort Study

Background and Purpose

The risk of stroke after a transient ischemic attack (TIA) for patients with a positive diffusion-weighted image (DWI), i.e., transient symptoms with infarction (TSI), is much higher than for those with a negative DWI. The aim of this study was to validate the predictive value of a web-based recurrence risk estimator (RRE; http://www.nmr.mgh.harvard.edu/RRE/) of TSI.

Methods

Data from the prospective hospital-based TIA database of the First Affiliated Hospital of Zhengzhou University were analyzed. The RRE and ABCD² scores were calculated within 7 days of symptom onset. The predictive outcome was ischemic stroke occurrence at 90 days. The receiver-operating characteristics curves were plotted, and the predictive value of the two models was assessed by computing the C statistics.

Results

A total of 221 eligible patients were prospectively enrolled, of whom 46 (20.81%) experienced a stroke within 90 days. The 90-day stroke risk in high-risk TSI patients (RRE ≥4) was 3.406-fold greater than in those at low risk (P <0.001). The C statistic of RRE (0.681; 95% confidence interval [CI], 0.592–0.771) was statistically higher than that of ABCD² score (0.546; 95% CI, 0.454–0.638; Z = 2.115; P = 0.0344) at 90 days.

Conclusion

The RRE score had a higher predictive value than the ABCD² score for assessing the 90-day risk of stroke after TSI.

TIA Management: Should TIA Patients be Admitted? Should TIA Patients Get Combination Antiplatelet Therapy?

Transient ischemic attack (TIA) has gained increasing attention over the last 2 decades with the realization that the condition is common, portends potentially serious consequences, and, when identified early, can be evaluated and treated to modify future risk. In this review, we examine the issues of whether all TIA patients need admission and whether such patients should receive short-term dual antiplatelet therapy. Not all patients require admission if evaluation and treatment are done promptly. There may be a role for dual antiplatelet therapy, but the results of further clinical trials will help provide better clarity on which patients are the best candidates for this treatment.