An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

Development and Validation of a Risk Score for Predicting Ischemic Stroke After Transient Ischemic Attack

BACKGROUND

A risk stratification scale is essential to identify high-risk patients who had transient ischemic attack (TIA) to prevent subsequent permanent disability caused by ischemic stroke.

OBJECTIVE

This study aimed to develop and validate a scoring system to predict acute ischemic stroke within 90 days after TIA in an emergency department (ED).

METHODS

We retrospectively analyzed the data of patients with TIA in a stroke registry between January 2011 and September 2018. Characteristics, medication history, electrocardiogram (ECG), and imaging findings were collected. Univariable and multivariable stepwise logistic regression analyses were performed to create an integer point system. The area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow (HL) test were used to examine discrimination and calibration. Youden's Index was also used to determine the best cutoff value.

RESULTS

A total of 557 patients were included, and the occurrence rate of acute ischemic stroke within 90 days after TIA was 5.03%. After multivariable analysis, a new integer point system was created-MESH (Medication Electrocardiogram Stenosis Hypodense) score-which contained medication history (antiplatelet medication taken before admission, 1 point), right bundle branch block on electrocardiogram (1 point), intracranial stenosis ≥ 50% (1 point), and size of the hypodense area on computed tomography (diameter ≥ 4 cm, 2 points). The MESH score showed adequate discrimination (AUC = 0.78) and calibration (HL test = 0.78). The best cutoff value was 2 points, with a sensitivity of 60.71% and specificity of 81.66%.

CONCLUSIONS

The MESH score indicated improved accuracy for TIA risk stratification in the ED setting.

Copeptin Implementation on Stroke Prognosis

Predicting functional outcome following stroke is considered to be of key importance in an attempt to optimize overall stroke care. Although clinical prognostic tools have been widely implemented, optimal blood biomarkers might be able to yield additional information regarding each stroke survivor's propensity for recovery. Copeptin seems to have interesting prognostic potential poststroke. The present review aims to explore the prognostic significance of copeptin in stroke patients. Literature research of two databases (MEDLINE and Scopus) was conducted to trace all relevant studies published between 16 February 2012 and 16 February 2022 that focused on the utility of copeptin as a prognostic marker in acute stroke setting. 25 studies have been identified and included in the present review. The predictive ability of copeptin regarding both functional outcome and mortality appears to be in the range of established clinical variables, thus highlighting the added value of copeptin evaluation in stroke management. Apart from acute ischemic stroke, the discriminatory accuracy of the biomarker was also demonstrated among patients with transient ischemic attack, intracerebral hemorrhage, and subarachnoid hemorrhage. Overall, copeptin represents a powerful prognostic tool, the clinical implementation of which is expected to significantly facilitate the individualized management of stroke patients.

Clinical Diagnosis and Magnetic Resonance Imaging in Patients With Transient and Minor Neurological Symptoms: A Prospective Cohort Study

BACKGROUND

The utility of magnetic resonance imaging (MRI) brain in patients with transient or minor neurological symptoms is uncertain. We sought to determine the proportion of participants with transient or minor neurological symptoms who had MRI evidence of acute ischemia at different clinical probabilities of transient ischemic attack (TIA) or minor stroke.

METHODS

Cohort of participants with transient or minor neurological symptoms from emergency and outpatient settings. Clinicians at different levels of training gave each participant a diagnostic probability (probable when TIA/stroke was the most likely differential diagnosis; possible when TIA/stroke was not the most likely differential diagnosis; or uncertain when diagnostic probability could not be given) before 1.5 or 3T brain MRI ≤5 days from onset. Post hoc, each clinical syndrome was defined blind to MRI findings as National Institute of Neurological Disorders and Stroke criteria TIA/stroke; International Headache Society criteria migraine aura; non-TIA focal symptoms; or nonfocal symptoms. MRI evidence of acute ischemia was defined by 2 reads of MRI. Stroke was ascertained for at least 90 days and up to 18 months after recruitment.

RESULTS

Two hundred seventy-two participated (47% female, mean age 60, SD 14), 58% with MRI ≤2 days of onset. Most (92%) reported focal symptoms. MR evidence of acute ischemia was found, for stroke/TIA clinical probabilities of probable 23 out of 75 (31% [95% CI, 21%-42%]); possible 26 out of 151 (17% [12%-24%]); and uncertain 9 out of 43, (20% [10%-36%]). MRI evidence of acute ischemia was found in National Institute of Neurological Disorders and Stroke criteria TIA/stroke 40 out of 95 (42% [32%-53%]); migraine aura 4 out of 38 (11% [3%-25%]); non-TIA focal symptoms 16 out of 99 (16% [10%-25%]); and no focal features 1 out of 29 (3% [0%-18%]). After MRI, a further 14 (5% [95% CI, 3-8]) would be treated with an antiplatelet drug compared with treatment plan before MRI. By 18 months, a new ischemic stroke occurred in 9 out of 61 (18%) patients with MRI evidence of acute ischemia and 2 out of 211 (1%) without (age-adjusted hazard ratio, 13 [95% CI, 3-62]; P<0.0001).

CONCLUSIONS

MRI evidence of acute brain ischemia was found in about 1 in 6 transient or minor neurological symptoms patients with a nonstroke/TIA initial diagnosis or uncertain diagnosis. Methods to determine the clinical and cost-effectiveness of MRI are needed in this population.

Comparison of Outcomes of Ischemic Stroke Initially Imaged With Cranial Computed Tomography Alone vs Computed Tomography Plus Magnetic Resonance Imaging

IMPORTANCE

Patients with acute ischemic stroke often undergo magnetic resonance imaging (MRI) in addition to computed tomography (CT), but its association with clinical outcomes is uncertain.

OBJECTIVE

To assess whether clinical outcomes of patients with acute ischemic stroke with initial CT alone were noninferior to those with additional MRI.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective observational propensity score-matched cohort study of clinical outcomes at discharge and 1 year for patients hospitalized with acute ischemic stroke was conducted at an academic medical center between January 2015 and December 2017. Data collection from an electronic medical record system performed from May 2020 through January 2022 was not completely blinded. Noninferiority margins were based on the designs of previous randomized clinical trials of ischemic stroke treatments. Statistical analysis was performed in January 2022. Participants were adults hospitalized with acute ischemic stroke with admission diagnosis based on CT. Exclusion criteria were primarily missing data. From 508 eligible patients, all 123 cases with additional MRI were propensity-score matched to 123 controls without.

EXPOSURE

MRI after initial diagnosis.

MAIN OUTCOMES AND MEASURES

Death or dependence at hospital discharge (modified Rankin Scale score of 3-6) and stroke or death occurring in survivors within 1 year after discharge.

RESULTS

Among 246 participants, the median age was 68 years (IQR, 58-78.8 years) and 131 (53.0%) were men. Death or dependence at discharge occurred more often in patients with additional MRI (59 of 123 [48.0%]) than in those with CT alone (52 of 123 [42.3%]; absolute difference, 5.7%; 95% CI, -6.7% to 18.1%), meeting the -7.50% criterion for noninferiority. Stroke or death within 1 year after discharge determined for 225 of 235 (96%) survivors occurred more often in patients with additional MRI (22 of 113 [19.5%]) than in those with CT alone (14 of 112 [12.5%]; relative risk, 1.14; 95% CI, 0.86-1.50), meeting the 0.725 relative risk criterion for noninferiority.

CONCLUSIONS AND RELEVANCE

This propensity score-matched cohort study of patients hospitalized with acute ischemic stroke found that a diagnostic imaging strategy of initial CT alone was noninferior to initial CT plus additional MRI with regard to clinical outcomes at discharge and at 1 year. Further research is needed to determine which patients hospitalized with acute ischemic stroke benefit from MRI.

Cerebral Vascular Dysfunctions Detected in Human Small Vessel Disease and Implications for Preclinical Studies

Cerebral small vessel disease (SVD) is highly prevalent and a common cause of ischemic and hemorrhagic stroke and dementia, yet the pathophysiology is poorly understood. Its clinical expression is highly varied, and prognostic implications are frequently overlooked in clinics; thus, treatment is currently confined to vascular risk factor management. Traditionally, SVD is considered the small vessel equivalent of large artery stroke (occlusion, rupture), but data emerging from human neuroimaging and genetic studies refute this, instead showing microvessel endothelial dysfunction impacting on cell-cell interactions and leading to brain damage. These dysfunctions reflect defects that appear to be inherited and secondary to environmental exposures, including vascular risk factors. Interrogation in preclinical models shows consistent and converging molecular and cellular interactions across the endothelial-glial-neural unit that increasingly explain the human macroscopic observations and identify common patterns of pathology despite different triggers. Importantly, these insights may offer new targets for therapeutic intervention focused on restoring endothelial-glial physiology.

Plasma neurofilament light predicts mortality in patients with stroke

Given the heterogeneity of stroke brain injury, there is a clear need for a biomarker that determines the degree of neuroaxonal injury across stroke types. We evaluated whether blood neurofilament light (NFL) would fulfill this purpose for patients with acute cerebral infarction (ACI; N = 227), aneurysmal subarachnoid hemorrhage (aSAH; N = 58), or nontraumatic intracerebral hemorrhage (ICH; N = 29). We additionally validated our findings in two independent cohorts of patients with ICH (N = 96 and N = 54) given the scarcity of blood biomarker studies for this deadliest stroke type. Compared to healthy individuals (N = 79 and N = 48 for the discovery and validation cohorts, respectively), NFL was higher for all stroke types. NFL associated with radiographic markers of brain tissue damage. It correlated with the extent of early ischemic injury in patients with ACI, hemorrhage severity in patients with aSAH, and intracranial hemorrhage volume in patients with ICH. In all patients, NFL independently correlated with scores from the NIH Stroke Scale, the modified Rankin Scale, and the Mini-Mental State Examination at blood draw, which respectively assess neurological, functional, and cognitive status. Furthermore, higher NFL concentrations independently associated with 3- or 6-month functional disability and higher all-cause mortality. These data support NFL as a uniform method to estimate neuroaxonal injury and forecast mortality regardless of stroke mechanism. As a prognostic biomarker, blood NFL has the potential to assist with planning supportive and rehabilitation services and improving clinical trial efficiency for stroke therapeutics and devices.

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.

Cost-Effectiveness of Advanced Neuroimaging for Transient and Minor Neurological Events in the Emergency Department

Background Accurate diagnosis of patients with transient or minor neurological events can be challenging. Recent studies suggest that advanced neuroimaging can improve diagnostic accuracy in low-risk patients with transient or minor neurological symptoms, but a cost-effective emergency department diagnostic evaluation strategy remains uncertain. Methods and Results We constructed a decision-analytic model to evaluate 2 diagnostic evaluation strategies for patients with low-risk transient or minor neurological symptoms: (1) obtain advanced neuroimaging (magnetic resonance imaging brain and magnetic resonance angiography head and neck) on every patient or (2) current emergency department standard-of-care clinical evaluation with basic neuroimaging. Main probability variables were: proportion of patients with true ischemic events, strategy specificity and sensitivity, and recurrent stroke rate. Direct healthcare costs were included. We calculated incremental cost-effectiveness ratios, conducted sensitivity analyses, and evaluated various diagnostic test parameters primarily using a 1-year time horizon. Cost-effectiveness standards would be met if the incremental cost-effectiveness ratio was less than willingness to pay. We defined willingness to pay as $100 000 US dollars per quality-adjusted life year. Our primary and sensitivity analyses found that the advanced neuroimaging strategy was more cost-effective than emergency department standard of care. The incremental effectiveness of the advanced neuroimaging strategy was slightly less than the standard-of-care strategy, but the standard-of-care strategy was more costly. Potentially superior diagnostic approaches to the modeled advanced neuroimaging strategy would have to be >92% specific, >70% sensitive, and cost less than or equal to standard-of-care strategy's cost. Conclusions Obtaining advanced neuroimaging on emergency department patient with low-risk transient or minor neurological symptoms was the more cost-effective strategy in our model.

Increased concentration of serum gamma-glutamyl transferase in ischemic stroke patients

BACKGROUND:

Stroke is responsible for the largest proportion of neurological disorders causing a significant morbidity. Gamma-glutamyl transferase (GGT) enzyme has an active involvement in atherosclerosis through its role in oxidative and inflammatory mechanisms. Recent evidence suggests that serum GGT is related to the risk and prognosis of cerebrovascular diseases.

METHODS:

A total of 200 patients (100 with acute ischemic stroke and 100 without stroke) were recruited from various medical wards and medical intensive care unit. Categorical variables were compared between two groups using Chi-squared test and odds ratio (OR). Independent sample t-test was used to see to compare mean GGT level of stroke patients with control.

RESULTS:

There was no statistical difference with respect to distribution of age groups (χ² = 1.25, P = 0.741) and gender (χ² = 2.678, P = 0.1018) between cases and controls. Mean age of stroke patients (mean [M] = 61.7, standard deviation [SD] = 13.8) did not differ from controls (M = 62.2, SD = 13.6), P = 0.80. The odds of suffering from diabetes were significantly higher in stroke patients than cases (OR = 2.25, P = 0.005). Independent sample t-test found a significant difference in serum GGT level between cases (M = 57.47, SD = 11.8) and control (M = 41.72, SD = 7.5), P ≤ 0.0001.

CONCLUSIONS:

Serum GGT was significantly higher in stroke patients than age-sex-matched nonstroke patients. Association remained significant in stroke patients irrespective of age, gender, and other risk factors. Stroke patients with diabetes, hypertension, dyslipidemia, obesity, and smoking had higher level serum GGT level than those without these risk factors. Prospective cohort studies can further explore the potential of GGT as a predictor of acute ischemic stroke.

One-Minute Multi-contrast Echo Planar Brain MRI in Ischemic Stroke: A Retrospective Observational Study of Diagnostic Performance

BACKGROUND

Fast multi-contrast echo planar MRI (EPIMix) has comparable diagnostic performance to standard MRI for detecting brain pathology but its performance in detecting acute cerebral infarctions has not been determined.

PURPOSE

To assess the diagnostic performance of EPIMix for the detection of acute cerebral infarctions.

STUDY TYPE

Retrospective observational cohort.

POPULATION

One hundred and seventy-two consecutive patients with a clinical suspicion of non-hyperacute ischemic stroke (January 2018 to December 2019).

FIELD STRENGTH AND SEQUENCE

1.5 T or 3 T. EPIMix ((echo-planar based: diffusion weighted (DWI), T2*-weighted, T2-weighted, T2- and T1-fluid attenuated inversion recovery (FLAIR) images) vs. standard MRI: echo-planar DWI, echo-planar T2*-weighted or susceptibility weighted, turbo spin-echo T2-weighted, T2- and T1-FLAIR turbo spin-echo sequences.

ASSESSMENT

Three neuroradiologists rated EPIMix and standard MRI on two separate occasions. Incongruent assessments were resolved in consensus with the fourth reader. The ratings included the diagnostic category (acute infarct, normal, and other pathology). Congruent diagnoses together with consensus diagnoses served as the reference standard.

STATISTICAL TESTS

The diagnostic performance of EPIMix and standard MRI against the reference standard was calculated by the area under the receiver operating characteristic curve (AUC) and compared by DeLong's test. Sensitivity and specificity were determined. Inter-rater agreements were evaluated by Fleiss's kappa.

RESULTS

Of 172 patients (61 ± 16 years, 103 men), acute infarcts were present in 80/172 (47%), normal findings in 60/172 (35%), and other pathology in 32/172 (19%). Across readers, the AUCs were .94-.95 for EPIMix and .95-.99 for standard MRI, with overlapping 95% CI (P = .02-.18). Inter-rater agreement for EPIMix was 0.90 and for standard MRI was 0.93. The sensitivity for EPIMix and standard MRI was 88-91% and 91-98%, respectively, while the specificity was 98-100% and 98-99%, both with overlapping 95% CI.

CONCLUSION

Multi-contrast echo planar MRI showed a high but marginally lower diagnostic performance compared to standard MRI for the detection and characterization of acute brain infarct.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Outcomes and resource use of patients with large hemispheric infarction and cerebral edema: analysis of real-world data

OBJECTIVE

Large hemispheric infarction (LHI) is associated with a high likelihood of the evolution of life-threatening edema. Few studies have assessed real-world clinical outcomes and management strategies among patients with LHI. The objective of this study was to describe the management, in-hospital outcomes, and direct healthcare resource burden of patients with LHI, as well as those of patients with subsequent cerebral edema.

METHODS

This observational, retrospective cohort study analyzed de-identified data from US adult patients using the IBM MarketScan Hospital Drug Database (Q4-2015 to Q4-2017). Patients were included in the "Possible LHI" or the "Other Ischemic Strokes" cohorts using ICD-10 diagnosis codes. Patients with possible LHI were further categorized into "LHI with Edema" and "LHI without Edema" subgroups using diagnosis and procedure codes. Select clinical and economic outcomes were compared between cohorts and subgroups using multivariable regressions.

RESULTS

Of 79,201 eligible encounters with ischemic strokes, 11,772 unique patients were assigned to the Possible LHI cohort while 67,429 were assigned to the Other Ischemic Strokes cohort. Among patients with possible LHI, 869 (7%) were assigned to the LHI with Edema subgroup and 10,903 (93%) were assigned to the LHI without Edema subgroup. Patients in the Possible LHI cohort had longer hospital stays (mean difference [MD] [95%CI] = 2.6 [2.4;2.8] days), higher total facility charges (MD [95%CI] = $28,656 [26,794;30,524]), and higher odds of death (odds ratio [95%CI] = 2.2 [2.0;2.4]) than the Other Ischemic Strokes cohort. Among patients with possible LHI, the incremental clinical and resource burden was further exacerbated in the subgroup of patients with edema (hospital days: MD [95%CI] = 5.0 [3.9;6.2] days; total facility charges: MD [95%CI] = $59,585 [50,816;67,583]; mortality: odds ratio [95%CI] = 10.3 [8.5;12.4]).

CONCLUSIONS

Among patients with ischemic strokes, LHI was associated with increased clinical management and direct healthcare resource burden in real-world hospital settings. The burden was substantially increased among patients who developed cerebral edema.

Diagnosis of non-consensus transient ischaemic attacks with focal, negative, and non-progressive symptoms: population-based validation by investigation and prognosis

BACKGROUND

Diagnosis of transient ischaemic attacks (TIAs) can be difficult. There is consensus on classic symptoms (eg, motor weakness, dysphasia, hemianopia, monocular visual loss) but no consensus on several monosymptomatic events with sudden-onset, non-progressive, focal negative symptoms (eg, isolated diplopia, dysarthria, vertigo, ataxia, sensory loss, and bilateral visual disturbance), with much variation in investigation and treatment.

METHODS

We prospectively ascertained and investigated all strokes and sudden onset transient neurological symptoms in a population of 92 728 people (no age restrictions) from Oxfordshire, UK, who sought medical attention at nine primary care practices or at the John Radcliffe Hospital, Oxford, UK (Oxford Vascular Study). Patients classified at baseline with minor ischaemic stroke (National Institutes of Health Stroke Score <5), classic TIA, or non-consensus TIA were treated according to secondary prevention guidelines. Risks of stroke (7-day, 90-day, and 10-year risks) and risks of all major vascular events (from the time of first event, and from the time of seeking medical attention) were established by face-to-face follow-up visits and were compared with the risk expected from age and sex-specific stroke incidence in the underlying study population.

FINDINGS

Between April 1, 2002, and March 31, 2018, 2878 patients were identified with minor ischaemic stroke (n=1287), classic TIA (n=1021), or non-consensus TIA (n=570). Follow-up was to Oct 1, 2018 (median 5·2 [IQR 2·6-9·2] years). 577 first recurrent strokes after the index event occurred during 17 009 person-years of follow-up. 90-day stroke risk from time of the index event after a non-consensus TIA was similar to that after classic TIA (10·6% [95% CI 7·8-12·9] vs 11·6% [95% CI 9·6-13·6]; hazard ratio 0·87, 95% CI 0·64-1·19; p=0·43), and higher than after amaurosis fugax (4·3% [95% CI 0·6-8·0]; p=0·042). However, patients with non-consensus TIA were less likely to seek medical attention on the day of the event than were those with classic TIA (336 of 570 [59%] vs 768 of 1021 [75%]; odds ratio [OR] 0·47, 95% CI 0·38-0·59; p<0·0001) and were more likely to have recurrent strokes before seeking attention (45 of 570 [8%] vs 47 of 1021 [5%]; OR 1·77, 95% CI 1·16-2·71; p=0·007). After excluding such recurrent strokes, 7-day stroke risk after seeking attention for non-consensus TIA (2·9% [95% CI 1·5-4·3]) was still considerably higher than the expected background risk (relative risk [RR] 203, 95% CI 113-334), particularly if the patient sought attention on the day of the index event (5·0% [2·1-7·9]; RR 300, 137-569). 10-year risk of all major vascular events was similar for non-consensus and classic TIAs (27·1% [95% CI 22·8-31·4] vs 30·9% [27·2-33·7]; p=0·12). Baseline prevalence of atrial fibrillation, patent foramen ovale, and arterial stenoses were also similar for non-consensus TIA and classic TIA, although stenoses in the posterior circulation were more frequent with non-consensus TIA (OR 2·21, 95% CI 1·59-3·08; p<0·0001).

INTERPRETATION

Patients with non-consensus TIA are at high early and long-term risk of stroke and have cardiovascular pathological findings on investigation similar to those of classic TIA. Designation of non-consensus TIAs as definite cerebrovascular events will increase overall TIA diagnoses by about 50%.

FUNDING

Wellcome Trust, National Institute for Health Research Oxford Biomedical Research Centre, Wolfson Foundation, Masonic Charitable Foundation, and British Heart Foundation.

Application of the P300 potential in cognitive impairment assessments after transient ischemic attack or minor stroke

Background The aims of this study were to determine the relationships between changes inlatency and amplitude of the P300 event-related potential component and cognitive impairmentsin patients after a transient ischemic attack (TIA) or a minor stroke and to assess thesuitability of the P300 for screening for cognitive impairments.Material and Method Sixty-five TIA or minor stroke patients diagnosed at the NeurologyDepartment of Beijing Tiantan Hospital, Capital Medical University from June 2015 toDecember 2016 and 30 healthy people evaluated in the same period were included. Allpatients were examing neuropsychological scales and event-related potentials within7 ± 3 days of onset of the disease. The TIA/minor stroke group was divided into normal cognition group(NC) and cognitive impairment group. The cognitive impairment group was further divided into vascular cognitive impairment with no dementia(VCIND) group and vascular dementia (VD) group to analyze the relationship between P300 latency.Results The P300 latency at each recording electrode was longer in the NC and VCIND groups than healthy control group (P < 0.001), the P300 latency of VCIND group longer than NC group (P < 0.001). When the P300-Fz latency cut-off value was 358.6 ms,the sensitivity for diagnosing cognitive impairment in patients after TIA/minor stroke was 0.875 and the specificity was 0.765.Conclusions The P300 latency delay can be used to detect cognitive impairments in patients after TIA/minor stroke and the P300-Fz latency is more sensitive for diagnosing cognitiveimpairments in TIA/minor stroke patients.

Application of neutrophil to lymphocyte ratio to identify CT-negative cerebral infarction with nonfocal symptoms

Background

The neutrophil to lymphocyte ratio (NLR) has emerged as a strong predictor of mortality in stroke patients. Our study aimed to investigate the correlation between NLR and cerebral infarction with nonfocal symptoms confirmed by diffusion-weighted imaging (DWI) (+).

Methods

A total of 439 patients with nonfocal stroke symptoms with CT-negative findings were included from January 1 to December 31, 2018. All patients underwent a head MRI examination within seven days following a head CT examination. The patients’ demographics, medical history, presenting symptoms, and stroke location were recorded. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to identify variables with a significant association with cerebral infarction.

Results

Cerebral infarction was detected in 79 (18%) patients confirmed by DWI(+), located mostly in the cerebellum (40.51%). Dizziness (85.19%) was the most common symptom. The cerebral infarction group showed a higher prevalence of hypertension (P<0.0001), diabetes mellitus (P<0.0001), and smoking status (P=0.001) than non-cerebral infarction group. The NLR (P<0.0001) was higher in the cerebral infarction group. There was no significant difference in NIHSS (P=0.09). Logistic analysis revealed that male gender (P=0.046), a history of hypertension (P=0.001), diabetes mellitus (P=0.001), smoking (P=0.023), and NLR (P<0.0001) were the best predictors of cerebral infarction. When integrating sex, hypertension, diabetes mellitus, smoking and NLR, the area under ROC value of the combined method was 0.785, higher than any separate parameters (P<0.05).

Conclusions

NLR combined with male gender, a history of hypertension, diabetes mellitus, and smoking, could predict DWI-confirmed cerebral infarction with nonfocal neurologic symptoms with high diagnostic accuracy.

Room tilt illusion and subclavian steal - a case report

BACKGROUND

Room tilt illusion (RTI) is a rare symptom of higher vestibular dysfunction, consisting of a transient vertical rotation of the visual scene in the sagittal or coronal plane, most often 90^o or 180^o, without any alteration in shape, size and color of objects.

CASE PRESENTATION

A 63-year-old woman with a history of hypertension and chronic obstructive pulmonary disease went through an uncomplicated aortobifemoral graft surgery due to aortoiliac occlusive disease. Post-operatively she experienced five episodes, lasting from 10 to 30 min, with RTI; 90^o forward rotation of the visual scene in the sagittal plane. Work-up revealed subclavian steal grade 3, and transient ischemia of the central vestibular system of the brainstem was the presumed mechanism.

CONCLUSION

The course of episodic RTIs is often benign, but RTI may represent ischemia in the posterior cerebral circulation. Both stroke and otoneurologic workup are recommended. To our knowledge, this is the first case of RTI associated with subclavian steal reported.

Cohort Study of Features Used by Experts to Diagnose Transient Ischemic Attack

Background and Purpose

The diagnosis of transient ischemic attack (TIA) is largely dependent on a process of clinical decision-making that remains poorly characterized in the absence of a validated and accessible biomarker or imaging test. We performed a retrospective chart review to identify variables associated with a final neurologist diagnosis of TIA/stroke.

Methods

Records for all patients seen in The Ottawa Hospital's Stroke Prevention Clinic in 2015 were analyzed for patient and referral characteristics, features of the presenting neurological event, and final diagnosis by a stroke neurologist (classified as definite, possible, or definite not TIA/stroke). Multinomial logistic regression analysis with backward elimination was used to identify variables associated with the final diagnosis.

Results

Our inclusion criteria were met by 1894 patients. After backward elimination, 23 potentially important variables were identified, including monocular vision loss (odds ratio [OR]: 30.4, 95% confidence interval [CI]: 14.6-63.3), symptoms of sudden onset (OR: 28.3, 95% CI: 14.2-56.2), unilateral weakness affecting 2 or 3 of face, arm, or leg (OR: 17.7, 95% CI: 9.8-31.7), and homonymous hemianopia (OR: 16.6, 95% CI: 8.1-34.0).

Conclusions

Accurate diagnosis of TIA is essential to initiating appropriate secondary stroke prevention therapies. A focus on elements of the patient history most commonly associated with a final diagnosis of TIA/stroke may help to identify patients in greatest need of urgent SPC assessment and allow for the provision of effective and efficient stroke prevention services.

Cost-effectiveness of empagliflozin in the UK in an EMPA-REG OUTCOME subgroup with type 2 diabetes and heart failure

Aims

Heart failure (HF) and type 2 diabetes (T2D), common co‐morbidities, translate into worse patient prognoses and higher direct costs than for either condition alone. Empagliflozin has been shown to markedly reduce cardiovascular (CV) deaths and HF hospitalizations (HHF) in HF patients with T2D. This study evaluated the lifetime cost‐effectiveness of supplementing standard of care (SoC) with empagliflozin, relative to SoC alone, in HF patients with T2D from the UK payer perspective.

Methods and results

An existing discrete‐event simulation model was adapted for the economic evaluation. Risk equations developed from time‐dependent parametric survival analyses using patient‐level HF subpopulation data from the EMPA‐REG OUTCOME trial were employed to predict CV and renal events. Non‐CV death, utility weights, and costs were drawn from UK sources. Quality‐adjusted life years (QALYs) and costs were discounted at 3.5% per annum. Relative to SoC, empagliflozin with SoC yielded fewer first HHF, recurrent HHF, CV death, and non‐fatal myocardial infarction but more non‐fatal stroke events. Empagliflozin with SoC vs. SoC alone was associated with increased average life expectancy (10.80 vs. 9.59 LYs) and quality of life (6.27 vs. 5.62 QALYs), though at higher lifetime cost (£18 197 vs. £16 829) per person, resulting in an incremental cost‐effectiveness ratio of £2093 per QALY. The probability of empagliflozin being cost‐effective in the HF subpopulation at a £20 000 per QALY willingness‐to‐pay threshold was 91%.

Conclusions

This analysis suggests that adding empagliflozin to SoC in HF patients with T2D constitutes a cost‐effective use of UK healthcare resources and may provide long‐term health benefits to patients.

Contemporary Management of Acute Ischemic Stroke Across the Continuum: From TeleStroke to Intra-Arterial Management

In this comprehensive contemporary review of acute ischemic stroke management, what is new and different will be highlighted beginning with prehospital stroke systems of care, emergency medical systems, and mobile stroke units, followed by hospital stroke teams, emergency evaluation, telemedicine, and brain and vascular imaging, and finishing with emergency treatments including thrombolysis and mechanical thrombectomy.

Diagnostic accuracy of acute infarcts in multiple cerebral circulations for cardioembolic stroke: Literature review and meta-analysis

OBJECTIVE

To determine the diagnostic value of acute infarcts in multiple cerebral circulations (AIMCC) on MRI diffusion-weighted imaging (DWI) for cardioembolism (CE) stroke subtype in adult patients hospitalized with acute ischemic stroke, we conducted a systematic literature review and meta-analysis.

METHODS

MEDLINE was searched via PubMed for articles reporting patients hospitalized with acute ischemic stroke with MRI DWI categorized as AIMCC vs other and use of Trial of Org 10172 in Acute Stroke Treatment (TOAST) Criteria for cardioembolism subtype. Measures of diagnostic accuracy were calculated from the retrieved studies.

RESULTS

Seven eligible articles comprised 5813 patients. Bivariate random effects models estimated sensitivity 0.19 (95% CI, 0.13 to 0.27), specificity 0.89 (0.86 to 0.91), positive predictive value 0.37 (0.30 to 0.45), negative predictive value 0.76 (0.7 to 0.82), positive likelihood ratio 1.70 (1.13 to 2.57) and negative likelihood ratio 0.91 (0.83 to 1).

INTERPRETATION

The pattern of AIMCC on DWI is of limited diagnostic value. It is not sufficiently accurate to exclude cardiac pathology by a negative test nor does a positive test indicate a major increase in the probability of identifying a potential cardioembolic source.

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.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Exploring the Cost-Effectiveness of Mechanical Thrombectomy Beyond 6 Hours Following Advanced Imaging in the United Kingdom

Supplemental Digital Content is available in the text.

In the United Kingdom, mechanical thrombectomy (MT) for acute ischemic stroke patients assessed beyond 6 hours from symptom onset will be commissioned up to 12 hours provided that advanced imaging (AdvImg) demonstrates salvageable brain tissue. While the accuracy of AdvImg differs across technologies, evidence is limited regarding the proportion of patients who would benefit from late MT. We compared the cost-effectiveness of 2 care pathways: (1) MT within and beyond 6 hours based on AdvImg selection versus (2) MT only within 6 hours based on conventional imaging selection. The impact of varying AdvImg accuracy and prior probability for acute ischemic stroke patients to benefit from late MT was assessed.

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.

[When are contrast agents really needed? : Cross-sectional imaging with computed tomography and magnetic resonance imaging]

CLINICAL ISSUE

The intravenous administration of contrast agents increases the contrast between diverse tissues and vessels against their surroundings in both computed tomography (CT) and magnetic resonance imaging (MRI) scans and has been generously used for years. There are only a few scientific publications that have systematically evaluated the impact of this contrast-enhancing technique over noncontrast enhancing techniques.

RADIOLOGICAL STANDARD

According to these publications and our clinical experiences, there are far more indications to use non-contrast-enhancing techniques as they are used in clinical practice. The most important requirement to renounce the use of a contrast agent is sufficient clinical information and differentiated justified indication. The present review shows useful non-contrast-enhanced examination techniques for neuroradiology, musculoskeletal system, lymphatic system, and thorax, including the hearth, abdomen and breasts.

CLINICAL RECOMMENDATIONS

Good indications for non-contrast imaging are generally follow-ups. In cerebral related questions, like in traumatic or atraumatic emergencies, transient ischemic attacks, minor stroke diagnostic, dementia and in follow-ups of multiple sclerosis, there is usually no need for contrast agent. Examinations of the musculoskeletal systems and follow-up examinations of the lymphatic system can generally be done without a contrast agent. There is no major loss of value in CT and MRI scans of the thorax by examining without contrast. The value of using a contrast agent in the abdomen is far less than expected. Up to now use of a contrast agent is essential in evaluating questions related to vessels or angiomatous tissue and in breast MRI.

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.

How do neurologists diagnose transient ischemic attack: A systematic review

Background

Identifying and treating patients with transient ischemic attack is an effective means of preventing stroke. However, making this diagnosis can be challenging, and over a third of patients referred to stroke prevention clinic are ultimately found to have alternate diagnoses.

Aims

We performed a systematic review to determine how neurologists diagnose transient ischemic attack.

Summary of review

A systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using MEDLINE, Embase, and the Cochrane Library databases. Publications eligible for inclusion were those that included information on the demographic or clinical features neurologists use to diagnose transient ischemic attacks or transient ischemic attack–mimics. Of 1666 citations, 210 abstracts were selected for full-text screening and 80 publications were ultimately deemed eligible for inclusion. Neurologists were more likely to diagnose transient ischemic attack based on clinical features including negative symptoms or speech deficits. Patients with positive symptoms, altered level of consciousness, or the presence of nonfocal symptoms such as confusion or amnesia were more likely to be diagnosed with transient ischemic attack–mimic. Neurologists commonly include mode of onset (i.e. sudden versus gradual), recurrence of attacks, and localizability of symptoms to a distinct vascular territory in the diagnostic decision-making process. Transient ischemic attack diagnosis was more commonly associated with advanced age, preexisting hypertension, atrial fibrillation, and other vascular risk factors.

Conclusions

Neurologists rely on certain clinical and demographic features to distinguish transient ischemic attacks from mimics, which are not currently reflected in widely used risk scores. Clarifying how neurologists diagnose transient ischemic attack may help frontline clinicians to better select patients for referral to stroke prevention clinics.

Clinical skills or high-tech MR in TIA patients: what makes the difference?

BACKGROUND

TIA has been recently re-defined as "a transient episode of neurological dysfunction caused by ischemia without acute infarction." The gold standard to exclude the presence of ischemic lesions is acute brain MR. However, in many clinical settings, the 24/7 availability of MR is, at best, irregular. Being so, an appropriate adoption of this definition, which excludes the presence of ischemic lesions, can only be equally irregular. Our aim was to retrospectively compare the long-term outcomes of patients receiving acute care for TIA diagnosed with the new, tissue-based definition, and those diagnosed only on symptom duration.

METHODS

We analyzed 480 patients (227 males) from two centers: group 1 consisted of 162 patients with time-defined TIA; group 2 of 315 patients with negative brain DW-MRI (tissue-based TIAs). We considered the combined recurrence of TIA, stroke, myocardial infarction, and angina as endpoints.

RESULTS

Both groups had a similar mean follow-up duration (38.3 months vs. 37.2 months) and were comparable for vascular risk factors, clinical features, and etiology. The combined endpoint rates were 11.1% for both groups, and the rates for segregate endpoints did not differ between groups. Recurrence was correlated with atrial fibrillation, diabetes, and high diastolic blood pressure.

CONCLUSIONS

The long-term outcomes of TIA patients did not differ according to the definitions applied. Therein suggesting that, even without acute MRI results, a clinical diagnosis seemed to be enough to assure prompt medical treatment and similar long-term outcomes.

Improved detectability of acute and subacute brainstem infarctions by combining standard axial and thin-sliced sagittal DWI

BACKGROUND AND PURPOSE

Most false negative findings in DWI of ischemic stroke are in patients with minor deficits clinically localized to the brainstem. Our goal was to evaluate the benefit of a thin-sliced sagittal DWI in addition to conventional axial DWI at 1.5T for the detection of brainstem infarctions.

METHODS

Data of patients with symptoms consistent with acute and subacute brainstem infarction and an MRI examination including standard axial DWI and thin-sliced sagittal DWI were retrospectively analyzed. Patients with the later diagnosis of a TIA, an inflammation or a tumor of the brainstem were excluded from analysis. Diffusion restrictions were identified by two independent raters blinded for the final clinical diagnosis in three separate reading steps: First, only axial DWI, secondly only sagittal DWI, and lastly both DWIs together. Presence and size of DWI-lesions were documented for each plane. Differences between the observers were settled in consensus in a separate joint reading.

RESULTS

Of 73 included patients, 46 patients were clinically diagnosed with brainstem infarction. Inter-observer agreement was excellent for the detection of brainstem lesions in axial and sagittal DWI (kappa = 0.94 and 0.97). In 28/46 patients (60.9%) lesions were detected in the axial plane alone, whereas in 6 more patients (73.9%) lesions were detected in the review of both sequences together. All lesions undetectable in the axial plane were smaller than 5 mm in cranio-caudal direction.

CONCLUSIONS

Thin-sliced sagittal DWI in addition to axial DWI improves the detection rate of brainstem infarction with little additional expenditure of time.

What is new in stroke imaging and intervention?

Recent updates to guidelines around brain imaging in stroke and transient ischaemic attack are reviewed. A more detailed examination of advanced brain imaging in acute stroke is presented. The recent evidence for endovascular mechanical thrombectomy in acute stroke is reviewed. The implications of delivering thrombectomy are discussed.

What is new in stroke imaging and intervention?

Recent updates to guidelines around brain imaging in stroke and transient ischaemic attack are reviewed. A more detailed examination of advanced brain imaging in acute stroke is presented. The recent evidence for endovascular mechanical thrombectomy in acute stroke is reviewed. The implications of delivering thrombectomy are discussed.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Optimizing the Definitions of Stroke, Transient Ischemic Attack, and Infarction for Research and Application in Clinical Practice

BACKGROUND AND PURPOSE

Until now, stroke and transient ischemic attack (TIA) have been clinically based terms which describe the presence and duration of characteristic neurological deficits attributable to intrinsic disorders of particular arteries supplying the brain, retina, or (sometimes) the spinal cord. Further, infarction has been pathologically defined as death of neural tissue due to reduced blood supply. Recently, it has been proposed we shift to definitions of stroke and TIA determined by neuroimaging results alone and that neuroimaging findings be equated with infarction.

METHODS

We examined the scientific validity and clinical implications of these proposals using the existing published literature and our own experience in research and clinical practice.

RESULTS

We found that the proposals to change to imaging-dominant definitions, as published, are ambiguous and inconsistent. Therefore, they cannot provide the standardization required in research or its application in clinical practice. Further, we found that the proposals are scientifically incorrect because neuroimaging findings do not always correlate with the clinical status or the presence of infarction. In addition, we found that attempts to use the proposals are disrupting research, are otherwise clinically unhelpful and do not solve the problems they were proposed to solve.

CONCLUSION

We advise that the proposals must not be accepted. In particular, we explain why the clinical focus of the definitions of stroke and TIA should be retained with continued sub-classification of these syndromes depending neuroimaging results (with or without other information) and that infarction should remain a pathological term. We outline ways the established clinically based definitions of stroke and TIA, and use of them, may be improved to encourage better patient outcomes in the modern era.

Comparison of Stroke Prediction Accuracy of ABCD2 and ABCD3-I in Patients with Transient Ischemic Attack: A Meta-Analysis

BACKGROUND

A direct comparison of the stroke prediction utility of the ABCD2 and ABCD3-I scores has not been performed. Thus, we conducted a diagnostic meta-analysis and applied the results to a hypothetical cohort of 1000 patients with transient ischemic attack (TIA) to assess the power of stroke prediction by ABCD2 and ABCD3-I scores.

METHODS

Medline, PubMed, Embase, and manuscript references were searched to identify studies that directly compared the stroke predictive powers of ABCD2 and ABCD3-I scores. We conducted a diagnostic meta-analysis using bivariate random effects models, and the predictive powers of ABCD2 and ABCD3-I scores were assessed by their summary sensitivity and specificity. Then, we applied the results to a hypothetical cohort of 1000 patients with TIA to calculate the effect per 1000 patients triaged for stroke prevention in a virtual setting.

RESULTS

Of the 35 identified studies on ABCD2 and ABCD3-I, 6 studies (7364 participants) directly compared the diagnostic accuracies of ABCD2 and ABCD3-I scores for occurrence of a future stroke. The pooled sensitivities of ABCD2 versus ABCD3-I were 79.9% (62.2%-90.6%) versus 96.1% (90.2%-98.5%) at 7 days (P = .022), and 76.6% (63.8%-85.8%) versus 94.6% (88.9%-97.5%) at 90 days (P = .001). The pooled specificities of ABCD2 versus ABCD3-I were 29.2% (18.2%-43.3%) versus 17.7% (8.5%-33.3%) at 7 days (P = .214), and 40.3% (25.0%-57.7%) versus 20.2% (12.6%-30.6%) at 90 days (P = .032).

CONCLUSIONS

ABCD3-I scores had a better sensitivity but poorer specificity than ABCD2 scores. However, in community-based referring settings, it is more suitable to use ABCD2 at initial triage and deciding on urgency of specialist assessment. The prognostic utility of each of the components of the scores should be carefully considered rather than dichotomized scores during clinical triage.

Long-Term Effect of Participation in an Early Exercise and Education Program on Clinical Outcomes and Cost Implications, in Patients with TIA and Minor, Non-Disabling Stroke

Participation in exercise and education programs following transient ischemic attack (TIA) or minor stroke may decrease cardiovascular disease risk. The purpose of this study was to assess the long-term effect (3.5 years) of an exercise and education program administered soon after TIA or minor stroke diagnosis on clinical outcome measures (stroke classification and number, patient deaths, hospital/emergency department admission) and cost implications obtained from standard hospital records. Hospital records were screened for 60 adults (male, n = 31; 71 ± 10 years), diagnosed with TIA or non-disabling stroke, who had previously been randomised and completed either an 8-week exercise and education program, or usual care control. Follow-up clinical outcomes and cost implications were obtained 3.5 ± 0.3 years post-exercise. Participants randomised to the exercise and education program had significantly fewer recurrent stroke/TIAs (n = 3 vs. n = 13, Cohen's d = 0.79) than the control group (P ≤ 0.003). Similar finding were reported for patient deaths (n = 0 vs. n = 4, d = 0.53), and hospital admissions (n = 48 vs. n = 102, d = 0.54), although these findings were only approaching statistical significance. The relative risk (mean; 95%CI) of death, stroke/TIAs and hospital admissions were 0.11 (0.01 to 1.98), 0.23 (0.07 to 0.72) and 0.79 (0.57 to 1.09), respectively. Hospital admission costs were significantly lower for the exercise group ($9041 ± 15,080 NZD [~$6000 ± 10,000 USD]) than the control group ($21,750 ± 22,973 NZD [~$14,000 ± 15,000 USD]) during the follow-up period (P < 0.05, d = 0.69). The present study demonstrates the long-term patient benefit and economic importance of providing secondary prevention, exercise and education programs for patients with TIA and minor stroke. URL: http://www.anzctr.org.au/ ; Trial Registration Number: ACTRN12611000630910.

Stroke mimic diagnoses presenting to a hyperacute stroke unit

Stroke services have been centralised in several countries in recent years. Diagnosing acute stroke is challenging and a high proportion of patients admitted to stroke units are diagnosed as a non-stroke condition (stroke mimics). This study aims to describe the stroke mimic patient group, including their impact on stroke services. We analysed routine clinical data from 2,305 consecutive admissions to a stroke unit at St George's Hospital, London. Mimic groupings were derived from 335 individual codes into 17 groupings. From 2,305 admissions, 555 stroke mimic diagnoses were identified (24.2%) and 72% of stroke mimics had at least one stroke risk factor. Common mimic diagnoses were headache, seizure and syncope. Medically unexplained symptoms and decompensation of underlying conditions were also common. Median length of stay was 1 day; a diagnosis of dementia (p=0.028) or needing MRI (p=0.006) was associated with a longer stay. Despite emergency department assessment by specialist clinicians and computed tomography brain, one in four suspected stroke patients admitted to hospital had a non-stroke diagnosis. Stroke mimics represent a heterogeneous patient group with significant impacts on stroke services. Co-location of stroke and acute neurology services may offer advantages where service reorganisation is being considered.

Temporal Trends in the Use of Investigations After Stroke or Transient Ischemic Attack

BACKGROUND

Guidelines recommend that patients with stroke or transient ischemic attack (TIA) undergo neuroimaging and cardiac investigations to determine etiology and guide treatment. It is not known how the use of these investigations has changed over time and whether there have been associated changes in management.

OBJECTIVES

To evaluate temporal trends in the use of brain and vascular imaging, echocardiography, and antithrombotic and surgical therapy after stroke or TIA.

RESEARCH DESIGN

We analyzed 42,738 patients with stroke or TIA presenting to any of the 11 regional stroke centers in Ontario, Canada between 2003 and 2012 using the Ontario Stroke Registry database. The study period was divided into 1-year intervals and we used the Cochran-Armitage test to determine trends over time.

RESULTS

Between 2003/2004 and 2011/2012, the proportion of patients undergoing brain imaging increased from 96% to 99%, as did the proportion receiving ≥3 brain scans (21%-39%), magnetic resonance imaging (13%-50%), vascular imaging (62%-88%), or echocardiography (52%-70%) (P<0.0001 for all comparisons). There was an increase in the proportion receiving any antithrombotic therapy (83%-91%, P<0.0001) but no change in use of anticoagulation (25% overall and 68% in subgroup with atrial fibrillation) or carotid revascularization (1.4%-1.5%, P=0.49).

CONCLUSIONS

The use of investigations after stroke has increased over time without concomitant changes in medical or surgical management. Although initial neurovascular imaging is in accordance with practice guidelines, the use of multiple imaging procedures and routine echocardiography are of uncertain clinical effectiveness.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Transient ischemic attack: management in the emergency department and impact of an outpatient neurovascular clinic

OBJECTIVES

1) To evaluate whether transient ischemic attack (TIA) management in emergency departments (EDs) of the Nova Scotia Capital District Health Authority followed Canadian Best Practice Recommendations, and 2) to assess the impact of being followed up in a dedicated outpatient neurovascular clinic.

METHODS

Retrospective chart review of all patients discharged from EDs in our district from January 1, 2011 to December 31, 2012 with a diagnosis of TIA. Cox proportional hazards models, Kaplan-Meier survival curve, and propensity matched analyses were used to evaluate 90-day mortality and readmission.

RESULTS

Of the 686 patients seen in the ED for TIA, 88.3% received computed tomography (CT) scanning, 86.3% received an electrocardiogram (ECG), 35% received vascular imaging within 24 hours of triage, 36% were seen in a neurovascular clinic, and 4.2% experienced stroke, myocardial infarction, or vascular death within 90 days. Rates of antithrombotic use were increased in patients seen in a neurovascular clinic compared to those who were not (94% v. 86.3%, p<0.0001). After adjustment for age, sex, vascular disease risk factors, and stroke symptoms, the risk of readmission for stroke, myocardial infarction, or vascular death was lower for those seen in a neurovascular clinic compared to those who were not (adjusted hazard ratio 0.28; 95% confidence interval 0.08-0.99, p=0.048).

CONCLUSION

The majority of patients in our study were treated with antithrombotic agents in the ED and investigated with CT and ECG within 24 hours; however, vascular imaging and neurovascular clinic follow-up were underutilized. For those with neurovascular clinic follow-up, there was an association with reduced risk of subsequent stroke, myocardial infarction, or vascular death.

Erratum: An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

Corrections to thex-axis title of the right-hand side forest plot in Figures 10–12