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

A novel predictive model based on pericarotid adipose tissue and lumen stenosis for stroke risk in patients with asymptomatic carotid stenosis

The study aimed to investigate the predictive value of clinical characteristics, major computed tomography angiography (CTA) indexes of carotid AS (carotid lumen stenosis and plaque burden), and inflammatory pericarotid adipose tissue for acute stroke risk in patients with a moderate or higher degree of carotid stenosis. In all, 119 patients with unilateral carotid stenosis who underwent head and neck computed tomography angiography were included and assigned to the stroke group or non-stroke group according to magnetic resonance imaging. Pericarotid adipose tissue attenuation value, net enhancement value in the base phase and the enhancement phase, and atherosclerotic features (plaque burden and lumen stenosis) were recorded. Multivariate logistic regression analysis and the operating characteristic curve (ROC) were performed to establish a predictive model for the presence of acute ischemic stroke. ROC analysis showed that pericarotid adipose tissue attenuation value and lumen stenosis were predictive factors for stroke. The AUC of pericarotid adipose tissue attenuation (PCAT) attenuation, lumen stenosis, the novel prediction model independently constructed based on PCAT attenuation, and lumen stenosis resulted in 0.838 (95% CI 0.759-0.899), 0.700 (95% CI 0.826-0.944), and 0.942 (95% CI 0.884-0.977), respectively. The model had a sensitivity and specificity of 0.909 and 0.893, respectively, when the cutoff value was 0.388. We found that the risk model combining pericarotid adipose tissue attenuation value and lumen stenosis has significant predictive values for the presence of symptomatic stroke among patients with a moderate or higher degree of carotid stenosis.

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.

Intracranial arterial stenosis and recurrence in stroke patients with different risk stratifications by Essen stroke risk score

OBJECTIVES

We sought to investigate whether the prognostic value of intracranial arterial stenosis (ICAS) is consistent across different risk stratifications using the Essen Stroke Risk score (ESRS).

METHODS

We derived data from the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events trial. Patients without complete baseline brain imaging data were excluded. Participants were categorized into different risk groups based on ESRS (low risk, 0-2, and high risk ≥ 3). The main outcome was stroke recurrence within 3 and 12 months. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) of ICAS, and other factors associated with stroke recurrence within 3 and 12 months were estimated using the Cox regression method.

RESULTS

During the 3-month follow-up, 54 patients (7.9%) had recurrent stroke in the low-risk group, and 39 patients (9.6%) had recurrent stroke in the high-risk group. ICAS was associated with a higher risk of stroke within 3 months (HR = 2.761; 95%CI = 1.538-4.957; P < 0.001) in the low-risk group, but not in the high-risk group (HR = 1.501; 95%CI = 0.701-3.213; P = 0.296). ICAS was independently associated with higher recurrent risk in the low-risk group (HR = 2.540; 95%CI = 1.472-4.381; P < 0.001), but not in the high-risk group (HR = 1.951; 95%CI = 0.977-3.893; P = 0.058) within 12 months.

CONCLUSION

ICAS was an independent predictor of both 3- and 12-month stroke recurrence in low-risk but not high-risk patients with minor ischemic stroke or transient ischemic attack according to ESRS stratification.

Intracranial atherosclerotic disease: current management strategies

A stroke due to underlying intracranial large artery occlusion, which is atherosclerotic in nature, is known as intracranial atherosclerotic disease (ICAD). It is important to recognize that ischaemic stroke due to ICAD differs from extracranial disease and other stroke aetiologies and requires a nuanced approach. It is a significant cause of stroke worldwide, and severe symptomatic ICAD can present challenges from a therapeutic standpoint, including recurrent ischaemic stroke despite optimal management. Furthermore, exploring the underlying pathophysiological mechanisms responsible for the disease may be necessary while considering treatment options. This narrative review aims to provide an all-encompassing overview of this disease. Epidemiology and clinical pathophysiology will be explored in detail. The findings of large clinical trials will serve as a guide to finding the most optimized management strategies. Another critical question that arises is the treatment of acute ischaemic stroke due to large vessel occlusion with underlying intracranial atherosclerosis, is the treatment and clinical diagnosis the same as for other aetiologies of stroke (i.e. extracranial disease and nonvalvular atrial fibrillation)? Consequently, secondary prevention of patients with ischaemic stroke or transient ischaemic attack will be divided into medical therapy, risk factor control, and endovascular and surgical treatment options.

Borderzone Infarcts and Recurrent Cerebrovascular Events in Symptomatic Intracranial Arterial Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Intracranial arterial stenosis (ICAS)-related stroke occurs due to three primary mechanisms with distinct infarct patterns: (1) borderzone infarcts (BZI) due to impaired distal perfusion, (2) territorial infarcts due to distal plaque/thrombus embolization, and (3) plaque progression occluding perforators. The objective of the systematic review is to determine whether BZI secondary to ICAS is associated with a higher risk of recurrent stroke or neurological deterioration.

METHODS

As part of this registered systematic review (CRD42021265230), a comprehensive search was performed to identify relevant papers and conference abstracts (with ≥20 patients) reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAS. Subgroup analyses were performed for studies including any BZI versus isolated BZI and those excluding posterior circulation stroke. The study outcome included neurological deterioration or recurrent stroke during follow-up. For all outcome events, corresponding risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated.

RESULTS

A literature search yielded 4,478 records with 32 selected during the title/abstract triage for full text; 11 met inclusion criteria and 8 studies were included in the analysis (n=1,219 patients; 341 with BZI). The meta-analysis demonstrated that the RR of outcome in the BZI group compared to the no BZI group was 2.10 (95% CI 1.52-2.90). Limiting the analysis to studies including any BZI, the RR was 2.10 (95% CI 1.38-3.18). For isolated BZI, RR was 2.59 (95% CI 1.24-5.41). RR was 2.96 (95% CI 1.71-5.12) for studies only including anterior circulation stroke patients.

CONCLUSION

This systematic review and meta-analysis suggests that the presence of BZI secondary to ICAS may be an imaging biomarker that predicts neurological deterioration and/or stroke recurrence.

Recurrence risk in symptomatic intracranial stenosis treated medically in the real world

BACKGROUND

The risk of early recurrence in medically treated patients with intracranial atherosclerotic stenosis (ICAS) may differ in clinical trials versus real-world settings. Delayed enrollment may contribute to lower event rates in ICAS trials. We aim to determine the 30-day recurrence risk in a real-world setting of symptomatic ICAS.

METHODS

We used a comprehensive stroke center stroke registry to identify hospitalized patients with acute ischemic stroke or TIA due to symptomatic 50-99% ICAS. The outcome was recurrent stroke within 30 days. We used adjusted Cox regression models to identify factors associated with increased recurrence risk. We also performed a comparison of 30-day recurrent stroke rates in real world cohorts and clinical trials.

RESULTS

Among 131 hospitalizations with symptomatic 50-99% ICAS over 3 years, 80 hospitalizations of 74 patients (mean age 71.6 years, 55.41% men) met the inclusion criteria. Over 30 days, 20.6 % had recurrent stroke; 61.5% (8/13) occurred within first 7 days. The risk was higher in patients not receiving dual antiplatelet therapy (HR 3.92 95% CI 1.30-11.84, p = 0.015) and hypoperfusion mismatch volume >3.5 mL at a T max>6 s threshold (HR 6.55 95% CI 1.60-26.88, p < 0.001). The recurrence risk was similar to another real world ICAD cohort (20.2%), and higher than that seen in clinical trials (2.2%-5.7%), even in those treated with maximal medical treatment or meeting inclusion criteria for trials.

CONCLUSIONS

In patients with symptomatic ICAS, the real-world recurrence of ischemic events is higher than that seen in clinical trials, even in subgroups receiving the same pharmacological treatment strategies.

Genotype-Guided Dual Antiplatelet Use for Transient Ischemic Attack and Minor Stroke by Imaging Status: Subgroup Analysis of the CHANCE-2 Trial

OBJECTIVE

This study was performed to investigate whether ticagrelor/aspirin versus clopidogrel/aspirin can further reduce the residual risk of stroke recurrence in patients with positive diffusion-weighted imaging (DWI) in the High-Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE-2) trial.

METHODS

Patients with DWI data in the CHANCE-2 trial were included and divided into those with and without acute infarction according to their DWI findings. The primary efficacy outcome and safety outcome were stroke recurrence and moderate to severe bleeding within 3 months of follow-up, respectively.

RESULTS

Of the 6,412 patients enrolled in the CHANCE-2 trial, 5,796 (90.4%) patients with DWI data were included in the subgroup analysis. A total of 4,369 patients (75.4%) had an acute infarction on DWI. Patients with positive DWI had higher risk of recurrent stroke (8.1%) than those without infarction (2.2%) within 3-month follow-up. Compared with clopidogrel/aspirin, ticagrelor/aspirin was associated with lower risk of stroke in patients with positive DWI (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.52-0.80, p < 0.001) than in those negative DWI (HR = 1.22, 95% CI = 0.55-2.72, p = 0.63), with a significant interaction association (p for interaction = 0.049). The risk of moderate to severe bleeding was similar between ticagrelor/aspirin and clopidogrel/aspirin treatment in the different groups.

INTERPRETATION

Our study demonstrates that imaging evaluation should be emphasized before targeting the best candidates for genotype-guided dual antiplatelet therapy in future clinical research and practice. ANN NEUROL 2023.

MRA-detected intracranial atherosclerotic disease in patients with TIA and minor stroke

OBJECTIVES

Patients with TIA and minor stroke commonly undergo CT and CTA in the emergency department with subsequent MRI with MRA for further workup. The purpose of this study was to review outpatient MRIs for TIA/stroke patients to assess the additional benefit, if any, of the MRA sequence in the detection of intracranial atherosclerotic disease in patients for whom CTA had already been performed.

METHODS

The radiology reports of outpatient MRIs of the brain for TIA/minor stroke patients were retrospectively reviewed via the hospital PACS system. Following this, the imaging report from the patient's initial presentation to the emergency department was reviewed. This index imaging and subsequent MRI were compared to assess the incidence of new vascular findings detected on the MRA sequence in patients for whom CTA had already been performed. Where new lesions had been identified at follow-up, the imaging was retroactively reviewed to assess if they were present on the index imaging.

RESULTS

Two hundred seven consecutive patients were reviewed. Significant (> 50%) intracranial atherosclerotic disease was present on MRA in 18 patients (8.7%). This was a new finding in 11 patients. Five had initial CTA where the atherosclerosis was not detected. All 5 of these cases were located in the posterior cerebral arteries. Incidental aneurysms were seen in 14 (6.7%); 12 were a new finding at time of MRI.

CONCLUSION

The MRA sequence provides additional value by increasing the detection of clinically important intracranial atherosclerotic disease which may inform management in patients with minor stroke and TIA.

Retinal Artery Occlusion and Its Impact on the Incidence of Stroke, Myocardial Infarction, and All-Cause Mortality during 12-Year Follow-Up

The aim of the study was to evaluate the incidence of ischemic stroke, myocardial infarction, and all-cause mortality in patients with retinal artery occlusion (RAO). This single-center retrospective study included 139 patients diagnosed with RAO between 2009 and 2020. The control group included 139 age- and sex-matched patients without RAO who underwent cataract surgery. The year of the surgery corresponded to the year of RAO onset. During the 12-year follow-up, patients with RAO had a shorter time to death (49.95 vs. 15.74 months; p = 0.043), a higher all-cause mortality rate (log-rank p = 0.026, and a higher rate of the composite endpoint, including ischemic stroke, myocardial infarction, and all-cause mortality (log-rank p = 0.024), as compared with controls. Patients with RAO younger than 75 years showed a higher risk of cerebral ischemic stroke (log-rank p = 0.008), all-cause mortality (log-rank p = 0.023), and the composite endpoint (log-rank p = 0.001) than controls. However, these associations were not demonstrated for patients aged 75 years or older. Our study confirms that patients with RAO have a higher risk of all-cause mortality than those without RAO. Moreover, patients with RAO who are younger than 75 years are significantly more likely to experience ischemic stroke, death, or the composite endpoint after an occlusion event, as compared with individuals without RAO.

Essen score in the prediction of cerebrovascular events compared with cardiovascular events after ischaemic stroke or transient ischaemic attack: a nationwide registry analysis

BACKGROUND

The Essen risk score improves stratification of patients with acute ischemic stroke by early stroke recurrence. Recent study showed it could also predict myocardial infarction (MI). This study aimed to compare the Essen score's ability to predict cerebrovascular events with compared cardiovascular events.

METHODS

We included patients with acute ischaemic stroke or transient ischaemic attack within seven days from the Third China National Stroke Registry. One-year cumulative event rates of combined vascular events (a composite of MI, stroke recurrence or vascular death) and cardiac events (a composite of MI, heart failure or cardiac death) was estimated using the Kaplan-Meier method. The predictive value of the Essen score was assessed with C-statistics. In multivariate Cox regression analyses, we assessed whether Essen score, etiological subtype and imaging parameters were associated with outcomes.

RESULTS

Of 13,012 patients were included, the cumulative one-year event rates were 10.03% for combined vascular events and 0.77% for cardiac events, respectively. Compared with those with an Essen score < 3, patients with an Essen score ≥ 3 were more likely to have a subsequent combined vascular event [hazard ratio (HR) = 1.39, 95% CI: 1.24-1.55] and cardiac events (HR = 2.30, 95% CI: 1.53-3.44). The score tended to be more predictive of the risk of MI (C-statistic = 0.63, 95% CI: 0.55-0.71) and cardiac events (C-statistic = 0.62, 95% CI: 0.56-0.67) than stroke recurrence (C-statistic = 0.55, 95% CI: 0.54-0.57) and combined vascular events (C-statistic = 0.56, 95% CI: 0.54-0.57). In multivariable analysis after adjusted Essen score, patients with multiple acute infarctions or single acute infarctions and large artery atherosclerosis subtype were independently associated with an increased risk of combined vascular events. While the cardioembolism subtype was associated with an increased risk of cardiac events.

CONCLUSIONS

The Essen score is potentially more suitable for risk stratification of cardiovascular events than cerebrovascular events. Moreover, future predictive tools should take brain imaging findings and cause of stroke into consideration.

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.

Development and validation of visual grading system for stenosis in intracranial atherosclerotic disease on time-of-flight magnetic resonance angiography

OBJECTIVES

Although the overestimation problem of time-of-flight magnetic resonance angiography (TOF-MRA) applying the warfarin-aspirin symptomatic intracranial disease (WASID) method to assess intracranial arterial stenosis has often been suggested, no pertinent grading system for TOF-MRA has been developed. We aimed to develop and evaluate the performance of a visual grading system for intracranial arterial stenosis on TOF-MRA (MRA_VICAST).

METHODS

This single-center cohort study analyzed prospective observational registry data from a comprehensive stroke center between January 2014 and February 2020. Patients with confirmed stenosis of the intracranial large arteries who underwent confirmative digital subtraction angiography (DSA) were included; a 4-point grading system was developed based on physical characteristics of TOF-MRA. The overall diagnostic accuracies of MRA_VICAST for each grade, interobserver reproducibility, and positive predictive values for > 50% and > 70% stenoses were evaluated.

RESULTS

We analyzed 132 segments with intracranial atherosclerotic stenosis from 71 patients (34 men and 37 women; mean age, 61.0 ± 15.25 years; range, 21-89 years). The overall diagnostic accuracy of MRA_VICAST (93.9%, 124/132) was higher than that of MRA_WASID (50.8%, 67/132) for each grade. The degree of stenosis did not differ significantly between MRA_VICAST and DSA_WASID (p = .849). Regarding reproducibility, MRA_VICAST demonstrated excellent interobserver agreement (ICC, 0.989; 95% CI, 0.979-0.999). The positive predictive values of MRA_VICAST for the diagnosis of > 50% and > 70% stenoses were 97.3% and 100.0%, respectively.

CONCLUSIONS

The new intuitive grading system accurately and reliably determined the degree of stenosis in intracranial arterial atherosclerosis patients. MRA_VICAST could be a versatile alternative to MRA_WASID for evaluating intracranial arterial stenosis.

KEY POINTS

• In this retrospective diagnostic study (sample: 132 stenotic segments), the overall accuracy of the visual grading system (MRA_VICAST) was 94%, and positive predictive value for > 50% stenosis was 97%. • In the era of medical treatment for intracranial atherosclerotic stenosis, MRA_VICAST could be a versatile alternative method to MRA_WASID for evaluating intracranial arterial stenosis.

Ischaemic stroke on anticoagulation therapy and early recurrence in acute cardioembolic stroke: the IAC study

BACKGROUND AND PURPOSE

A subset of ischaemic stroke patients with atrial fibrillation (AF) have ischaemic stroke despite anticoagulation. We sought to determine the association between prestroke anticoagulant therapy and recurrent ischaemic events and symptomatic intracranial haemorrhage (sICH).

METHODS

We included consecutive patients with acute ischaemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from eight comprehensive stroke centres in the USA. We compared recurrent ischaemic events and delayed sICH risk using adjusted Cox regression analyses between patients who were prescribed anticoagulation (ACp) versus patients who were naïve to anticoagulation therapy prior to the ischaemic stroke (anticoagulation naïve).

RESULTS

Among 2084 patients in IAC, 1518 had prior anticoagulation status recorded and were followed for 90 days. In adjusted Cox hazard models, ACp was associated with some evidence of a higher risk higher risk of 90-day recurrent ischaemic events only in the fully adjusted model (adjusted HR 1.50, 95% CI 0.99 to 2.28, p=0.058) but not increased risk of 90-day sICH (adjusted HR 1.08, 95% CI 0.46 to 2.51, p=0.862). In addition, switching anticoagulation class was not associated with reduced risk of recurrent ischaemic events (adjusted HR 0.41, 95% CI 0.12 to 1.33, p=0.136) nor sICH (adjusted HR 1.47, 95% CI 0.29 to 7.50, p=0.641).

CONCLUSION

AF patients with ischaemic stroke despite anticoagulation may have higher recurrent ischaemic event risk compared with anticoagulation-naïve patients. This suggests differing underlying pathomechanisms requiring different stroke prevention measures and identifying these mechanisms may improve secondary prevention strategies.

Mapping Cerebrovascular Reactivity Impairment in Patients With Symptomatic Unilateral Carotid Artery Disease

Background

Comprehensive hemodynamic impairment mapping using blood oxygenation‐level dependent (BOLD) cerebrovascular reactivity (CVR) can be used to identify hemodynamically relevant symptomatic unilateral carotid artery disease.

Methods and Results

This prospective cohort study was conducted between February 2015 and July 2020 at the Clinical Neuroscience Center of the University Hospital Zurich, Zurich, Switzerland. One hundred two patients with newly diagnosed symptomatic unilateral internal carotid artery (ICA) occlusion or with 70% to 99% ICA stenosis were included. An age‐matched healthy cohort of 12 subjects underwent an identical BOLD functional magnetic resonance imaging examination. Using BOLD functional magnetic resonance imaging with a standardized CO₂ stimulus, CVR impairment was evaluated. Moreover, embolic versus hemodynamic ischemic patterns were evaluated on diffusion‐weighted imaging. Sixty‐seven patients had unilateral ICA occlusion and 35 patients unilateral 70% to 99% ICA stenosis. Patients with ICA occlusion exhibited lower whole‐brain and ipsilateral hemisphere mean BOLD‐CVR values as compared with healthy subjects (0.12±0.08 versus 0.19±0.04, P=0.004 and 0.09±0.09 versus 0.18±0.04, P<0.001) and ICA stenosis cohort (0.12±0.08 versus 0.16±0.05, P=0.01 and 0.09±0.09 versus 0.15±0.05, P=0.01); however, only 40 (58%) patients of the cohort showed significant BOLD‐CVR impairment. Conversely, there was no difference in mean BOLD‐CVR values between healthy patients and patients with ICA stenosis, although 5 (14%) patients with ICA stenosis showed a significant BOLD‐CVR impairment. No significant BOLD‐CVR difference was discernible between patients with hemodynamic ischemic infarcts versus those with embolic infarct distribution (0.11±0.08 versus 0.13±0.06, P=0.12).

Conclusions

Comprehensive BOLD‐CVR mapping allows for identification of hemodynamically relevant symptomatic unilateral carotid artery stenosis or occlusion.

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.

Imaging Parameters Predict Recurrence After Transient Ischemic Attack or Minor Stroke Stratified by ABCD2 Score

BACKGROUND AND PURPOSE

Whether imaging parameters would independently predict stroke recurrence in low-risk minor ischemic stroke (MIS) or transient ischemic attack (TIA) according to traditional score system (such as ABCD² score, which was termed on the basis of the initials of the five factors: age, blood pressure, clinical features, duration, diabetes) remains unclear. We sought to evaluate the association between imaging parameters and 1-year stroke recurrence in patients with TIA or MIS in different risk stratum stratified by ABCD² score.

METHODS

We included patients with TIA and MIS (National Institutes of Health Stroke Scale score ≤3) with complete baseline vessel and brain imaging data from the Third China National Stroke Registry III. Patients were categorized into different risk groups based on ABCD² score (low risk, 0-3; moderate risk, 4-5; and high risk, 6-7). The primary outcome was stroke recurrence within 1 year. Multivariable Cox proportional-hazards regression models were used to assess whether imaging parameters (large artery stenosis, infarction number) were independently associated with stroke recurrence.

RESULTS

Of the 7140 patients included, 584 patients experienced stroke recurrence within 1 year. According to the ABCD² score, large artery stenosis was associated with higher stroke recurrence in both low-risk (adjusted hazard ratio, 1.746 [95% CI, 1.200-2.540]) and moderate-risk group (adjusted hazard ratio, 1.326 [95% CI, 1.042-1.687]) but not in the high-risk group (P>0.05). Patients with multiple acute infarctions or single acute infarction had a higher risk of recurrent stroke than those with no infarction in both low- and moderate-risk groups, but not in the high-risk group.

CONCLUSIONS

Large artery stenosis and infarction number were independent predictors of 1-year stroke recurrence in low-moderate risk but not in high-risk patients with TIA or MIS stratified by ABCD² score. This finding emphasizes the importance of early brain and vascular imaging evaluation for risk stratification in patients with TIA or MIS.

Carotid Stenosis and Recurrent Ischemic Stroke: A Post-Hoc Analysis of the POINT Trial

BACKGROUND AND PURPOSE

Randomized trials demonstrated the benefit of dual antiplatelet therapy in patients with minor ischemic stroke or high-risk transient ischemic attack. We sought to determine whether the presence of carotid stenosis was associated with increased risk of ischemic stroke and whether the addition of clopidogrel to aspirin was associated with more benefit in patients with versus without carotid stenosis.

METHODS

This is a post-hoc analysis of the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) that randomized patients with minor ischemic stroke or high-risk transient ischemic attack within 12 hours from last known normal to receive either clopidogrel plus aspirin or aspirin alone. The primary predictor was the presence of ≥50% stenosis in either cervical internal carotid artery. The primary outcome was ischemic stroke. We built Cox regression models to determine the association between carotid stenosis and ischemic stroke and whether the effect of clopidogrel was modified by ≥50% carotid stenosis.

RESULTS

Among 4881 patients enrolled POINT, 3941 patients met the inclusion criteria. In adjusted models, ≥50% carotid stenosis was associated with ischemic stroke risk (hazard ratio, 2.45 [95% CI, 1.68-3.57], P<0.001). The effect of clopidogrel (versus placebo) on ischemic stroke risk was not significantly different in patients with <50% carotid stenosis (adjusted hazard ratio, 0.68 [95% CI, 0.50-0.93], P=0.014) versus those with ≥50% carotid stenosis (adjusted hazard ratio, 0.88 [95% CI, 0.45-1.72], P=0.703), P value for interaction=0.573.

CONCLUSIONS

The presence of carotid stenosis was associated with increased risk of ischemic stroke during follow-up. The effect of added clopidogrel was not significantly different in patients with versus without carotid stenosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03354429.

Impaired Distal Perfusion Predicts Length of Hospital Stay in Patients with Symptomatic Middle Cerebral Artery Stenosis

BACKGROUND AND PURPOSE

Perfusion imaging can risk stratify patients with symptomatic intracranial stenosis. We aim to determine the association between perfusion delay and length of hospital stay (LOS) in symptomatic middle cerebral artery (MCA) stenosis patients.

METHODS

This is a retrospective study of consecutive patients admitted to a comprehensive stroke center over 5 years with ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset due to MCA stenosis (50-99%) and underwent perfusion imaging. Patients were divided into three groups: mismatch volume ≥ 15 cc based on T max > 6 second delay, T max 4-6 second delay, and <4 second delay. The outcome was LOS, both as a continuous variable and categorical (≥7 days [prolonged LOS] vs. <7 days). We used adjusted regression analyses to determine the association between perfusion categories and LOS.

RESULTS

One hundred and seventy eight of 194 patients met the inclusion criteria. After adjusting for age and NIHSS, T max >6 second mismatch was associated with prolonged LOS (OR 2.94 95% CI 1.06-8.18; P = .039), but T max 4-6 second was not (OR 1.45 95% CI .46-4.58, P = .528). We found similar associations when LOS was a continuous variable for T max > 6 second (β coefficient = 2.01, 95% CI .05-3.97, P = .044) and T max 4-6 second (β coefficient = 1.24, 95% CI -.85 to 3.34, P = .244).

CONCLUSION

In patients with symptomatic MCA stenosis, T max > 6 second perfusion delay is associated with prolonged LOS. Prospective studies are needed to validate our findings.

Diagnostic Challenges in Outpatient Stroke: Stroke Chameleons and Atypical Stroke Syndromes

Failure to diagnose transient ischemic attack (TIA) or stroke in a timely fashion is associated with significant patient morbidity and mortality. In the outpatient or clinic setting, we suspect that patients with minor, transient, and atypical manifestations of cerebrovascular disease are most prone to missed or delayed diagnosis. We therefore detail common stroke chameleon symptoms as well as atypical stroke presentations, broadly review new developments in the study of diagnostic error in the outpatient setting, suggest practical clinical strategies for diagnostic error reduction, and emphasize the need for rapid consultation of stroke specialists when appropriate. We also address the role of psychiatric disease and vascular risk factors in the diagnostic evaluation and treatment of suspected stroke/TIA patients. We advocate incorporating diagnostic time-outs into clinical practice to assure that the diagnosis of TIA or stroke is considered in all relevant patient encounters after a detailed history and examination are conducted in the outpatient setting.

Dual antiplatelet therapy reduced stroke risk in transient ischemic attack with positive diffusion weighted imaging

Dual antiplatelet therapy (DAPT) reduced stroke risk in high-risk transient ischemic attack (TIA) patients assessed by ABCD2 score. Patients with positive diffusion-weighted imaging (DWI) were identified as imaging-based high-risk. The present study aims to investigate whether DAPT could reduce stroke risk in TIA with DWI positive. The study enrolled TIA patients within 72 h of onset from the prospective TIA database of the First Affiliated Hospital of Zhengzhou University. The predictive outcome was ischemic stroke at 90-day. The relationship between DAPT and stroke was analyzed in a cox proportional hazards model. The Kaplan–Meier curves of TIA patients with DAPT and monotherapy were plotted. Total of 661 TIA patients were enrolled, 279 of whom were DWI positive and 281 used DAPT. The 90-day stroke risk was higher in patients used monotherapy than those used DAPT in TIA with positive DWI (23.7% vs. 13.4%, p = 0.029). DAPT was associated with reduced stroke risk in TIA patients with positive DWI (hazard ratio [HR] = 0.54; 95% confidence interval [CI], 0.30–0.97; p = 0.037). However, the benefit didn’t exist in TIA patients with negative DWI (HR = 0.43; 95% CI, 0.14–1.33; p = 0.142). Early use of DAPT reduced stroke risk in TIA patients with positive DWI.

Association of elevated hs-CRP and multiple infarctions with outcomes of minor stroke or TIA: subgroup analysis of CHANCE randomised clinical trial

Background and purpose

The relationship of high-sensitive C-reactive protein (hs-CRP) levels and infarction numbers with the prognosis of stroke is uncertain. This study evaluated the association of different hs-CRP levels and infarction numbers with the prognosis of acute minor ischaemic stroke or transient ischaemic attack (TIA).

Methods

A subset of 807 patients with both hs-CRP measurement and baseline MRI was included from the Clopidogrel in High-risk Patients with Acute Non-disabling Cerebrovascular Events trial. The primary efficacy outcome was the occurrence of an ischaemic stroke at the 1-year follow-up. Infarction numbers were classified as multiple acute infarctions (MAIs), single acute infarction and no acute infarction (NAI). The association between different hs-CRP levels with different infarction numbers and the risk of any outcome was analysed using multivariable Cox regression models.

Results

Among the 807 patients, 84 (10.4%) patients had a recurrent ischaemic stroke within 1 year. After adjustment for conventional confounding factors, patients with both elevated hs-CRP levels and MAIs were associated with approximately 4.7-fold of risk of ischaemic stroke within 1 year (16.7% vs 3.5%, HR 4.68, 95% CI 1.54 to 14.23, p=0.007), compared with those with non-elevated hs-CRP levels and NAI. Similar results were observed for the composite events.

Conclusions

Combined elevated hs-CRP levels and MAIs may increase 1-year stroke risk stratification efficiency in patients with minor ischaemic stroke or TIA compared with using those markers alone, which indicated that the combination of inflammatory and imaging markers might improve the effectiveness of risk stratification concerning minor ischaemic stroke or TIA.

ClinicalTrials.gov Registry (NCT00979589).

Early ischaemic and haemorrhagic complications after atrial fibrillation-related ischaemic stroke: analysis of the IAC study

INTRODUCTION

Predictors of long-term ischaemic and haemorrhagic complications in atrial fibrillation (AF) have been studied, but there are limited data on predictors of early ischaemic and haemorrhagic complications after AF-associated ischaemic stroke. We sought to determine these predictors.

METHODS

The Initiation of Anticoagulation after Cardioembolic stroke study is a multicentre retrospective study across that pooled data from consecutive patients with ischaemic stroke in the setting of AF from stroke registries across eight comprehensive stroke centres in the USA. The coprimary outcomes were recurrent ischaemic event (stroke/TIA/systemic arterial embolism) and delayed symptomatic intracranial haemorrhage (d-sICH) within 90 days. We performed univariate analyses and Cox regression analyses including important predictors on univariate analyses to determine independent predictors of early ischaemic events (stroke/TIA/systemic embolism) and d-sICH.

RESULTS

Out of 2084 patients, 1520 patients qualified; 104 patients (6.8%) had recurrent ischaemic events and 23 patients (1.5%) had d-sICH within 90 days from the index event. In Cox regression models, factors associated with a trend for recurrent ischaemic events were prior stroke or transient ischemic attack (TIA) (HR 1.42, 95% CI 0.96 to 2.10) and ipsilateral arterial stenosis with 50%-99% narrowing (HR 1.54, 95% CI 0.98 to 2.43). Those associated with sICH were male sex (HR 2.68, 95% CI 1.06 to 6.83), history of hyperlipidaemia (HR 2.91, 95% CI 1.08 to 7.84) and early haemorrhagic transformation (HR 5.35, 95% CI 2.22 to 12.92).

CONCLUSION

In patients with ischaemic stroke and AF, predictors of d-sICH are different than those of recurrent ischaemic events; therefore, recognising these predictors may help inform early stroke versus d-sICH prevention strategies.

Impact of Infection on the Risk of Recurrent Stroke Among Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Infection occurs commonly in patients with acute ischemic stroke. We aimed to investigate the association of infection with short- and long-term risk of recurrent stroke in patients with ischemic stroke.

METHODS

Data were derived from ischemic stroke patients in 2 stroke registries: the CSCA (Chinese Stroke Center Alliance) program recorded medical data during hospitalization, and the CNSR-III (Third China National Stroke Registry) recorded the medical data during hospitalization and finished 1-year follow-up. Associations of infection (pneumonia or urinary tract infection) during hospitalization with recurrent stroke in short (during hospitalization) and long term (since 30 days to 1 year after stroke onset) were analyzed. Short-term outcomes were analyzed with logistic models and long-term outcomes with Cox models.

RESULTS

In the CSCA (n=789 596), the incidence of infection during hospitalization reached 9.6%. Patients with infection had a higher risk of stroke recurrence during hospitalization compared with patients without infection (10.4% versus 5.2%; adjusted odds ratio, 1.70 [95% CI, 1.65-1.75]; P<0.0001). In the CNSR-III (n=13 549), the incidence of infection during hospitalization was 6.5%. Infection during hospitalization was significantly associated with short-term risk of recurrent stroke (7.4% versus 3.9%; adjusted odds ratio, 1.40 [95% CI, 1.05-1.86]; P=0.02) but not with long-term risk of recurrent stroke (7.2% versus 5.2%; adjusted hazard ratio, 1.16 [95% CI, 0.88-1.52]; P=0.30).

CONCLUSIONS

Infection was an independent risk factor for high risk of early stroke recurrence during hospitalization, but we have not found its sustained effect on long-term recurrent risk in patients with acute ischemic stroke.

Hypoperfusion Distal to Anterior Circulation Intracranial Atherosclerosis is Associated with Recurrent Stroke

BACKGROUND AND PURPOSE

In patients with symptomatic vertebrobasilar intracranial atherosclerotic disease (ICAD), impaired distal flow predicts recurrent stroke, but limited data exist on the association between perfusion status and recurrent stroke in anterior circulation ICAD.

METHODS

This is a retrospective study of patients hospitalized for symptomatic ICAD with 50-99% stenosis of the intracranial carotid or middle cerebral artery. The primary outcome is recurrent symptomatic ischemic stroke in the territory of the artery with ≥50% stenosis within 90 days. The primary predictor is distal hypoperfusion on magnetic resonance (MR) or computed tomography (CT) perfusion, defined as a ≥15 mL volume of territory of the symptomatic artery with Tmax >6 seconds.

RESULTS

Fifty patients met inclusion criteria, including 15 (30%) with recurrent stroke and 15 (30%) with distal hypoperfusion. Distal hypoperfusion was present in 10 of 15 (66.7%) with recurrent stroke versus 5 of 35 (14.3%) without recurrent stroke (P < .001). The hazard ratio for recurrent stroke in patients with distal hypoperfusion was 6.80 (95% confidence interval [CI] 2.31-20.0).

CONCLUSION

Distal hypoperfusion in acutely symptomatic ICAD with 50-99% stenosis is associated with stroke recurrence. Distal hypoperfusion could be used to enrich future trials of secondary stroke prevention in ICAD patients.

Intracranial Atherosclerosis: A Disease of Functional, not Anatomic Stenosis? How Trans-Stenotic Pressure Gradients Can Help Guide Treatment

BACKGROUND

Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation.

OBJECTIVE

To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients.

METHODS

In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients.

RESULTS

Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements.

CONCLUSION

Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

Penumbra volume predicts unfavorable outcome in patients with acute minor stroke or transient ischemic attack

BACKGROUND

A subgroup of patients with acute minor stroke (AMS) or transient ischemic attack (TIA) become disabled due to disease progression (DP) or recurrent stroke within 3 months. The aim of this article is to identify the risk factors for DP in AMS/TIA patients. In the literature, no studies focused on computed tomography perfusion (CTP) in AMS/TIA patients at the acute stage.

METHODS

This retrospective study included patients with AMS or TIA (onset of symptoms ≤4.5 hours, baseline National Institutes of Health Stroke Scale [NIHSS] score of 0-4). DP was defined as a deterioration of NIHSS score of ≥2 points during hospitalization or modified Ranking Scale ≥2 at 3-month follow-up. Clinical data and imaging results were retrieved and measured for statistical analysis.

RESULTS

From 2011 to 2017, total 135 patients were eligible for further analysis: 28 patients (20.7%, DP group) and 107 patients (79.3%, non-DP group). The DP group had significantly higher larger penumbra volumes (p = 0.028). In univariate model of the logistic regression, patients with the following risk factors tended to have unfavorable outcome: female gender, higher HbA1c, chronic kidney disease stage ≥3b, intracranial atherosclerosis, and penumbra volume were associated unfavorable outcome, but larger deadcore volume was not. In further multivariate analysis, only penumbra volume >5 cm (p = 0.049, odds ratio [OR] = 3.21, 95% CI: 1.00-10.27) had the statistical significance. The cut-point value of the penumbra volume for unfavorable outcome in AMS/TIA patients was 4.73 cm.

CONCLUSION

One fifth of the AMS/TIA patients had unfavorable outcome at 90 days. In CTP performed within 4.5 hours after the onset of AMS/TIA, the penumbra volume (>5 cm) was a significant risk factor for DP, and the cut-point value was 4.73 cm. Further studies could be designed to involve this subgroup of patients for more aggressive treatment.

Acute insular infarction: Early outcomes of minor stroke with proximal artery occlusion

BACKGROUND AND PURPOSE

We hypothesized that admission insular infarcts could be associated with early neurological deterioration (END) in acute minor stroke with large vessel occlusion.

METHODS

Using acute and follow-up diffusion-weighted imaging (DWI), we assessed insular involvement including the percent insular ribbon infarction (PIRI) scores and follow-up lesion patterns in acute minor stroke (NIHSS ≤5) with MCA/ICA occlusion. Follow-up lesion patterns were classified as swelling, new lesions, or infarct growth. END was defined as any increase in the NIHSS score.

RESULTS

Among 166 patients (age: 66±12 y, 60.8% male), 82 (49.4%) had insular lesions on baseline DWI, and 64 (38.6%) had PIRI scores ≥2. On follow-up DWI, infarct growths, new lesions, and swelling were observed in 34.9%, 69.9%, and 29.5% of patients. Infarct growths were significantly more frequent in patients with insular infarcts (43.9%), especially those with a PIRI score of 2 (54.8%), than in patients without insular infarcts (p = 0.02). While END was not significantly different in patients with and without insular lesions, insular lesions were independently associated with infarct growths (OR 2.18, 95% CI 1.12-4.26, p = 0.02) and END due to infarct growth (OR 2.54, 95% CI 1.12-5.76, p = 0.03), particularly in those with PIRI scores ≥2.

CONCLUSION

In acute minor stroke with MCA/ICA occlusion, insular lesions on admission DWI, especially in patients with PIRI scores ≥2, were more likely to exhibit infarct growth and END due to infarct growth. This finding may help identify patients with higher risks of clinical worsening following acute minor stroke with large vessel occlusion.

Newly detected atrial fibrillation is associated with cortex-involved ischemic stroke

Background:

Both cortical and cortical-subcortical (cortex-involved) lesions are typically associated with embolic stroke, of which atrial fibrillation (AF) is the common cause. The aim of this study was to find out the associations between cortex-involved stroke, vascular risk factors, and the subtypes (discovery time and duration) of AF.

Methods:

This was an imaging study of the China Atrial Fibrillation Screening in Acute Ischemic Stroke Patients (CRIST) trial. Between October 2013 and June 2015, 1511 acute ischemic stroke or transient ischemic attack (TIA) patients within 7 days after stroke onset at 20 Chinese hospitals were enrolled in this prospective, multicenter cohort, cross-sectional study. The final analysis of this sub-study included 243 patients with AF with required magnetic resonance imaging (MRI) sequences. AF was diagnosed by 6-day Holter monitoring and classified by duration of 24 h. Two stroke specialists blinded to the clinical information reviewed MRI (diffusion-weighted MRI). The third stroke specialists, also blinded to the clinical information, assessed the conflicts. Adjusted large artery atherosclerosis as confounding factor, the associations between cortex-involved lesions, vascular risk factors, and the subtype of AF were evaluated by univariate and multivariate regression analyses.

Results:

Of 243 acute ischemic stroke patients with AF, 190 were known AF and 53 were newly detected AF. There were 28 patients with AF persistent >24 h and 25 persistent ≤24 h in newly detected AF. Patients with newly detected AF were likely to have a fewer history of stroke or TIA (16.98% vs. 36.31%, P = 0.008) and lower fasting blood glucose (5.91 ± 1.83 mmol/L vs. 6.75 ± 3.83 mmol/L, P = 0.030) than patients with known AF. Among these 243 patients, 102 (41.98%) patients were with cortex-involved lesions. Cortex-involved lesions were significantly related to newly detected AF persistent >24 h (odds ratio [OR]: 4.517, 95% confidence interval [CI]: 1.490–13.696, P = 0.008), proteinuria (OR: 3.431, 95% CI: 1.530–7.692, P = 0.021), and glycosylated hemoglobin (OR: 0.632, 95% CI: 0.464–0.861, P = 0.004).

Conclusions:

Compared to previously known AF, newly detected AF persistent >24 h was associated with cortex-involved ischemic stroke.

Clinical trial registration:

NCT02156765, https://clinicaltrials.gov/ct2/show/record/NCT02156765

Safety and Feasibility of a Rapid Outpatient Management Strategy for Transient Ischemic Attack and Minor Stroke: The Rapid Access Vascular Evaluation-Neurology (RAVEN) Approach

STUDY OBJECTIVE

Although most transient ischemic attack and minor stroke patients in US emergency departments (EDs) are admitted, experience in other countries suggests that timely outpatient evaluation of transient ischemic attack and minor stroke can be safe. We assess the feasibility and safety of a rapid outpatient stroke clinic for transient ischemic attack and minor stroke: Rapid Access Vascular Evaluation-Neurology (RAVEN).

METHODS

Transient ischemic attack and minor stroke patients presenting to the ED with a National Institutes of Health Stroke Scale score of 5 or less and nondisabling deficit were assessed for potential discharge to RAVEN with a protocol incorporating social and medical criteria. Outpatient evaluation by a vascular neurologist, including vessel imaging, was performed within 24 hours at the RAVEN clinic. Participants were evaluated for compliance with clinic attendance and 90-day recurrent transient ischemic attack and minor stroke and hospitalization rates.

RESULTS

Between December 2016 and June 2018, 162 transient ischemic attack and minor stroke patients were discharged to RAVEN. One hundred fifty-four patients (95.1%) appeared as scheduled and 101 (66%) had a final diagnosis of transient ischemic attack and minor stroke. Two patients (1.3%) required hospitalization (one for worsening symptoms and another for intracranial arterial stenosis caused by zoster) at RAVEN evaluation. Among the 101 patients with confirmed transient ischemic attack and minor stroke, 18 (19.1%) had returned to an ED or been admitted at 90 days. Five were noted to have had recurrent neurologic symptoms diagnosed as transient ischemic attack (4.9%), whereas one had a recurrent stroke (0.9%). No individuals with transient ischemic attack and minor stroke died, and none received thrombolytics or thrombectomy, during the interval period. These 90-day outcomes were similar to historical published data on transient ischemic attack and minor stroke.

CONCLUSION

Rapid outpatient management appears a feasible and safe strategy for transient ischemic attack and minor stroke patients evaluated in the ED, with recurrent stroke and transient ischemic attack rates comparable to historical published data.

Dual Antiplatelet Therapy in Transient Ischemic Attack and Minor Stroke With Different Infarction Patterns: Subgroup Analysis of the CHANCE Randomized Clinical Trial

Importance

Infarction patterns may serve as important imaging markers to assess the probability of stroke recurrence in transient ischemic attack (TIA) and minor stroke. However, it is unclear whether patients with different infarction patterns benefit differently from dual antiplatelet therapy.

Objectives

To investigate whether infarction patterns can stratify the risk of recurrent stroke and whether the efficacy and safety of clopidogrel plus aspirin vs aspirin alone are consistent in different infarction patterns after TIA or minor stroke.

Design, Setting, and Participants

In this prespecified imaging substudy of the Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events (CHANCE) randomized clinical trial, a total of 1342 patients with noncardioembolic TIA or minor stroke at 45 sites of CHANCE from October 1, 2009, to July 30, 2012, were included in this substudy. The final analysis was conducted on July 30, 2016, and included 1089 patients with required magnetic resonance imaging sequences. Infarction patterns were grouped into multiple acute infarctions (MAIs), single acute infarction (SAI), and no acute infarction (NAI) according to diffusion-weighted imaging.

Main Outcomes and Measures

Primary and secondary efficacy outcomes were stroke recurrence and new clinical vascular event after 3 months, respectively. The safety outcome was moderate to severe bleeding risk after 3 months.

Results

Among 1089 patients, the mean (SD) age was 63.1 (10.7) years and 731 patients (65%) were men. Patients with MAIs (hazard ratio [HR], 5.8; 95% CI, 2.2-15.1; P < .001) and SAI (HR, 3.9; 95% CI, 1.5-10.5; P = .007) had higher risk of recurrent stroke than those with NAI after adjustment for potential confounders at 3-month follow-up. Stroke recurrence occurred in 15 (10.1%) and 25 (18.8%) of patients with MAIs administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 0.5; 95% CI, 0.3-0.96; P = .04), 24 (8.9%) and 24 (8.5%) of patients with SAI administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 1.1; 95% CI, 0.6-2.0; P = .71), and 3 (2.6%) and 2 (1.4%) of patients with NAI administered clopidogrel plus aspirin and placebo plus aspirin, respectively (HR, 1.7; 95% CI, 0.3-11.1; P = .56), with P = .04 for treatment × infarction pattern interaction effect. Clopidogrel plus aspirin did not increase moderate to severe bleeding risk.

Conclusions and Relevance

Infarction patterns can efficiently stratify the risk of recurrent stroke within 3 months of noncardioembolic TIA or minor ischemic stroke. Patients with MAIs received the most pronounced clinical benefit from dual antiplatelet therapy without increasing the risk of moderate to severe bleeding. However, even if after dual antiplatelet treatment, patients with MAIs still had a risk of stroke recurrence as high as those with SAI.

Trial Registration

clinicaltrials.gov Identifier: NCT00979589.

Predictors of Poor Outcome in Patients with Minor Ischemic Stroke by Using Magnetic Resonance Imaging

Although the symptoms of minor ischemic stroke are mild, poor prognosis may occur if left untreated. Therefore, it is particularly important to identify the predictors that associated with poor outcome in patients presenting minor ischemic stroke. The aim of this study was to elucidate the predictors of progression by using magnetic resonance imaging (MRI). A total of 516 patients diagnosed with minor ischemic stroke were enrolled in this study. They were divided into two groups, the progressive group and non-progressive group, according to the modified Rankin Scale (mRS) with the cutoff value of 2 points on day 90 after the stroke onset. We compared the results of MRI scan between the two groups to investigate the potential independent determinants of progression using multivariate logistic regression analysis. Ninety of 516 patients (17.44%) underwent progression. There were 9 factors that were independently associated with poor outcome, including age (OR = 1.045, 95% CI 1.017-1.074), heart disease (OR = 2.021, 95% CI 1.063-3.841), baseline NIHSS score (OR = 1.662, 95% CI 1.177-2.347), limb motor disturbance (OR = 2.430, 95% CI 1.010-5.850), ataxia (OR = 2.929, 95% CI 1.188-7.221), early neurological deterioration (OR = 50.994, 95% CI 17.659-147.258), diameter of infarction (OR = 1.279, 95% CI 1.075-1.521), non-responsible vessel size (OR = 2.518, 95% CI 1.145-5.536), and large-artery atherosclerosis (OR = 2.010, 95% CI 1.009-4.003). This study indicated that age, heart disease, motor disturbance of limb, ataxia, early neurological deterioration, diameter of infarction, size of non-responsible vessels, and large-artery atherosclerosis can be used to assess the prognosis of patients with minor ischemic stroke.

Infarct Pattern, Perfusion Mismatch Thresholds, and Recurrent Cerebrovascular Events in Symptomatic Intracranial Stenosis

BACKGROUND AND PURPOSE

Studies have shown an association between infarct patterns and recurrent stroke in patients with symptomatic intracranial stenosis (sICAS) but there are limited data on associations with perfusion imaging mismatch profile. We aim to determine the association between infarct pattern, optimal mismatch profile definition, and recurrent cerebrovascular events (RCVE) in patients with anterior circulation sICAS.

METHODS

This is a retrospective study of consecutive patients with acutely sICAS admitted to a comprehensive stroke center over 18 month's period. Patients with sICAS underwent magnetic resonance perfusion (MRP) imaging within 24 hours from admission. Infarct patterns (internal BZ [IBZ], cortical BZ [CBZ], and core/perforator [C/P]) and RCVE within 90 days, were independently adjudicated by two reviewers. We compared mismatch profiles and recurrent event rates across infarct patterns.

RESULTS

Twenty-five patients met inclusion criteria; 28% had IBZ infarcts and overall RCVE rate was 32.0%. When compared to patients without IBZ infarcts, those with IBZ infarcts were more likely to have a target mismatch profile using T_max > 6 seconds (60% vs. 6.7%, P = .007) and RCVE (62.5% vs. 11.8%, P = .01). There were no associations between CBZ and C/P infarcts and target mismatch profiles and RCVE.

CONCLUSION

IBZ infarcts may be a surrogate marker of distal perfusion status and RCVE risk. Larger multicenter, prospective, core-lab blindly adjudicated studies are needed to confirm our findings.

Efficacy of High-intensity Statin Use for Transient Ischemic Attack Patients with Positive Diffusion-weighted Imaging

To determine whether positive or negative DWI TIA patients could get benefits from HST we conducted a cohort study which data from the prospective, hospital-based, TIA database of the First Affiliated Hospital of Zhengzhou University. The end-point was 7-day and 90-day incidence of stroke. Cox proportional hazard regression models were used to analyze the association between end-points and high-intensity statin treatment in TIA patients with positive and negative DWI. A total of 987 eligible TIA patients were analyzed. The stroke risk of patients with positive DWI was about a four-fold increase compared to that with negative DWI (7 d, 10.9 versus 1.8, p < 0.001 and 90 d, 18.3 versus 4.2, p < 0.001). After adjusting confounding factors, HST significantly improved both 7-day (HR 0.331, 95% CI 0.165–0.663; p = 0.002) and 90-day (HR 0.480, 95% CI 0.288–0.799; p = 0.005) outcomes in positive DWI patients. As a conclusion, high-intensity statin use reduces the 90 days’ recurrent stroke risk in DWI-positive TIA patients but not in DWI-negative patients.

Does all single infarction have lower risk of stroke recurrence than multiple infarctions in minor stroke?

BACKGROUND

Single acute infarction (SAI) usually had lower risk of stroke recurrence than multiple acute infarctions (MAIs) in minor stroke. To evaluate whether all SAI had lower risk of stroke recurrence than MAIs in minor stroke.

METHODS

We derived data from the imaging subgroup of the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Minor stroke were categorized into SAI and MAIs by infarction numbers in diffusion weighted imaging. SAI were classified as lacunar infarction and non-lacunar infarction. The outcome was stroke recurrence within one-year follow-up. We assessed the associations between infarction patterns and stroke recurrence using multivariable Cox regression models.

RESULTS

Overall, 834 patients with minor stroke were included in this subgroup, 553 SAI (381 lacunar infarction, 172 non-lacunar infarction) and 281 MAIs. The rate of stroke recurrence was 7.6%, 15.1% and 15.3% in lacunar infarction of SAI, non-lacunar infarction of SAI and MAIs at one year, respectively. Compared with MAIs, lacunar infarction of SAI had lower risk of stroke recurrence (hazard ratio [HR] 0.41, 95% confidence interval [CI] 0.21-0.80, P = 0.009), but not in non-lacunar infarction of SAI (HR 1.01, 95% CI 0.60-1.69, P = 0.98).

CONCLUSIONS

Lacunar infarction of SAI have lower risk of stroke recurrence than MAIs, while non-lacunar infarction of SAI might have similar risk as MAIs. Except for the number of infarctions, size and location should also be considered to stratify risk of stroke recurrence in minor stroke.

TRIAL REGISTRATION

http://www.clinicaltrials.gov Unique identifier: NCT00979589 . Date of registration: September 2009.

Dual antiplatelet therapy reduced stroke risk in high-risk patients with transient ischaemic attack assessed by ABCD3-I score

BACKGROUND AND PURPOSE

Several clinical trials have demonstrated that dual antiplatelet therapy (DAPT) benefited patients with transient ischaemic attack (TIA) with an ABCD2 score ≥4. The present study aimed to investigate whether the ABCD3-I score could be a more appropriate tool for selection of patients with TIA to receive DAPT in real-world settings.

METHODS

We derived data from the TIA database of The First Affiliated Hospital of Zhengzhou University. The predictive outcome was ischaemic stroke at 90 days. The additive interaction effect was presented by the attributable proportion due to interaction. Kaplan-Meier curves were plotted to present cumulative stroke rates in different risk categories with monotherapy and DAPT. Cox proportional hazards regression was used to determine risk factors associated with stroke.

RESULTS

Among 785 patients, the mean (SD) age was 56.95 (12.73) years and 77 patients (9.8%) had an ischaemic stroke at 90 days. A total of 55.8% of patients (attributable proportion due to interaction; 95% confidence interval, 20.8%-90.9%) were attributed to additive interaction of ABCD3-I score and antiplatelet therapy. Kaplan-Meier curves showed a significant difference between patients receiving monotherapy and DAPT in high-risk patients with TIA (P = 0.021). DAPT reduced 90-day stroke risk in high-risk patients with TIA as assessed independently by ABCD3-I score (adjusted hazard ratio, 0.43; 95% confidence interval, 0.20-0.92, P = 0.031). The benefit did not exist in low- and medium-risk patients by ABCD3-I score (patients with ABCD2 score ≥ 4 or <4).

CONCLUSIONS

High-risk patients with TIA assessed by ABCD3-I score received the most pronounced clinical benefit from early use of DAPT in real-world clinical experience.

What Threshold Defines Penumbral Brain Tissue in Patients with Symptomatic Anterior Circulation Intracranial Stenosis: An Exploratory Analysis

BACKGROUND AND PURPOSE

Impaired distal perfusion predicts neurological deterioration in large artery atherosclerosis. We aim to determine the optimal threshold of Tmax delay on perfusion imaging that is associated with neurological deterioration in patients with symptomatic proximal anterior circulation large artery stenosis.

METHODS

Data were abstracted from a prospective ischemic stroke database of consecutively enrolled patients with symptomatic proximal intracranial stenosis (internal carotid artery or M1 segment of the middle cerebral artery) who underwent magnetic resonance perfusion imaging within 24 hours of symptom onset during a 15-month period. Tissue volumes of perfusion delay Tmax 0-4 seconds, Tmax > 4 seconds, Tmax > 6 seconds, and Tmax > 8 seconds were calculated using an automated approach. A target mismatch (penumbra-core) was defined as ≥15mL of brain tissue using each of the Tmax threshold categories. The outcome was neurological deterioration at 30 days defined as new or worsening neurological deficits that are not attributed to a nonvascular etiology.

RESULTS

Among 52 patients with symptomatic intracranial stenosis, 26 patients met inclusion criteria. Neurological deterioration was associated with target mismatch profile defined according to Tmax > 6 seconds (66.7% [6/9] vs. 5.9% [1/17], P < .01) and Tmax >8 seconds (57.1% [4/7] vs. 15.8% [3/19], P = .05] but not according to Tmax > 4 seconds (27.3% [6/17] vs. 11.1% [1/9], P = .35].

CONCLUSIONS

A target mismatch profile using Tmax > 6 seconds may define tissue at risk in patients with acute symptomatic proximal anterior circulation intracranial stenosis. More studies are needed to confirm our findings.

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.

Prognosis of dolichoectasia in non-cardioembolic transient ischemic attack and minor stroke

Objectives This study aimed to estimate the prognosis of dolichoectasia in non-cardioembolic transient ischemic attack (TIA) and minor stroke patients. Methods Data were derived from the imaging subgroup of patients in the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Dolichoectasia was defined as ectasia (basilar artery diameter >4.5 mm) and dolichosis (either basilar artery bifurcation above the suprasellar cistern or lateral to the margin of the clivus or dorsum sellae). The prognosis included ischemic stroke recurrence and poor functional outcome (modified Rankin scale 2-6) at 12-month follow-up. The association of dolichoectasia with risk factors and prognosis of patients were assessed using multivariable Cox regression models. Results Overall, 1089 patients with magnetic resonance images in the CHANCE trial were included in this subanalysis. A total of 98 (9.0%) patients were detected with dolichoectasia, and 106 (9.7%) patients had a recurrent ischemic stroke at 12 months. Small artery occlusion (SAO) was more prevalent in patients with dolichoectasia compared with those without dolichoectasia (29.6% vs. 22.7%, hazard ratio [HR] 2.87, 95% confidence interval [CI] 1.59-5.17, p < 0.001). However, multivariate analysis showed no association of dolichoectasia with 12-month recurrent stroke (9.2% vs. 9.8%, HR, 1.15; 95%CI, 0.32-4.12; p = 0.83) and poor functional outcome (7.6% vs. 8.4%, odds ratio, 1.22; 95%CI, 0.24-6.08; p = 0.81) in the current subgroup analysis. Conclusions Dolichoectasia was significantly associated with SAO. There was no relationship between dolichoectasia and 12-month prognosis of patients with non-cardioembolic TIA or minor stroke.

Perfusion imaging and recurrent cerebrovascular events in intracranial atherosclerotic disease or carotid occlusion

Background

Large vessel disease stroke subtype carries the highest risk of early recurrent stroke. In this study we aim to look at the association between impaired perfusion and early stroke recurrence in patients with intracranial atherosclerotic disease or total cervical carotid occlusion.

Methods

This is a retrospective study from a comprehensive stroke center where we included consecutive patients 18 years or older with intracranial atherosclerotic disease or total cervical carotid occlusion admitted with a diagnosis of ischemic stroke within 24 h from symptom onset with National Institute Health Stroke Scale < 15, between 1 December 2016 and 30 June 2017. Patients with (1) evidence of ≥ 50% stenosis of a large intracranial artery or total carotid artery occlusion, (2) symptoms referable to the territory of the affected artery, and (3) perfusion imaging data using the RAPID processing software were included. The primary predictor was unfavorable perfusion imaging defined as Tmax > 6 s mismatch volume (penumbra volume–infarct volume) of 15 ml or more. The outcome was recurrent cerebrovascular events at 90 days defined as worsening or new neurological symptoms in the absence of a nonvascular cause attributable to the decline, or new infarct or infarct extension in the territory of the affected artery. We used Cox proportional hazards models to determine the association between impaired perfusion and recurrent cerebrovascular events.

Results

Sixty-two patients met our inclusion criteria; mean age 66.4 ± 13.1 years, 64.5% male (40/62) and 50.0% (31/62) with intracranial atherosclerotic disease. When compared to patients with favorable perfusion pattern, patients with unfavorable perfusion pattern were more likely to have recurrent cerebrovascular events (55.6% (10/18) versus 9.1% (4/44), p < 0.001). This association persisted after adjusting for potential confounders (adjusted hazard ratio 10.44, 95% confidence interval 2.30–47.42, p = 0.002).

Conclusion

Perfusion mismatch predicts recurrent cerebrovascular events in patients with ischemic stroke due to intracranial atherosclerotic disease or total cervical carotid occlusion. Studies are needed to determine the utility of revascularization strategies in this patient population.

Pioglitazone Prevents Stroke in Patients With a Recent Transient Ischemic Attack or Ischemic Stroke: A Planned Secondary Analysis of the IRIS Trial (Insulin Resistance Intervention After Stroke)

BACKGROUND

The IRIS trial (Insulin Resistance Intervention after Stroke) demonstrated that pioglitazone reduced the risk for a composite outcome of stroke or myocardial infarction among nondiabetic patients with insulin resistance and a recent stroke or transient ischemic attack. The current planned secondary analysis uses updated 2013 consensus criteria for ischemic stroke to examine the effect of pioglitazone on stroke outcomes.

METHODS

Participants were randomly assigned to receive pioglitazone (45 mg/d target dose) or placebo within 180 days of a qualifying ischemic stroke or transient ischemic attack and were followed for a maximum of 5 years. An independent committee, blinded to treatment assignments, adjudicated all potential stroke outcomes. Time to first stroke event was compared by treatment group, overall and by type of event (ischemic or hemorrhagic), using survival analyses and Cox proportional hazards models.

RESULTS

Among 3876 IRIS participants (mean age, 63 years; 65% male), 377 stroke events were observed in 319 participants over a median follow-up of 4.8 years. Pioglitazone was associated with a reduced risk for any stroke at 5 years (8.0% in comparison with 10.7% for the placebo group; hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.60-0.94; log-rank P=0.01). Pioglitazone reduced risk for ischemic strokes (HR, 0.72; 95% CI, 0.57-0.91; P=0.005) but had no effect on risk for hemorrhagic events (HR, 1.00; 95% CI, 0.50-2.00; P=1.00).

CONCLUSIONS

Pioglitazone was effective for secondary prevention of ischemic stroke in nondiabetic patients with insulin resistance.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00091949.

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.

Symptomatic Carotid Occlusion Is Frequently Associated With Microembolization

BACKGROUND AND PURPOSE

Symptomatic carotid artery disease is associated with significant morbidity and mortality. The pathophysiologic mechanisms of cerebral ischemia among patients with carotid occlusion remain underexplored.

METHODS

We conducted a prospective observational cohort study of patients hospitalized within 7 days of ischemic stroke or transient ischemic attack because of ≥50% carotid artery stenosis or occlusion. Transcranial Doppler emboli detection was performed in the middle cerebral artery ipsilateral to the symptomatic carotid. We describe the prevalence of microembolic signals (MES), characterize infarct topography, and report clinical outcomes at 90 days.

RESULTS

Forty-seven patients, 19 with carotid occlusion and 28 with carotid stenosis, had complete transcranial Doppler recordings and were included in the final analysis. MES were present in 38%. There was no difference in MES between those with carotid occlusion (7/19, 37%) compared with stenosis (11/28, 39%; P=0.87). In patients with radiographic evidence of infarction (n=39), 38% had a watershed pattern of infarction, 41% had a nonwatershed pattern, and 21% had a combination. MES were present in 40% of patients with a watershed pattern of infarction. Recurrent cerebral ischemia occurred in 9 patients (19%; 6 with transient ischemic attack, 3 with ischemic stroke). There was no difference in the rate of recurrence in those with compared to those without MES.

CONCLUSIONS

Cerebral embolization plays an important role in the pathophysiology of ischemia in both carotid occlusion and stenosis, even among patients with watershed infarcts. The role of aggressive antithrombotic and antiplatelet therapy for symptomatic carotid occlusions may warrant further investigation given our findings.

Have clinicians adopted the use of brain MRI for patients with TIA and minor stroke?

BACKGROUND

Use of MRI with diffusion-weighted imaging (DWI) can identify infarcts in 30%-50% of patients with TIA. Previous guidelines have indicated that MRI-DWI is the preferred imaging modality for patients with TIA. We assessed the frequency of MRI utilization and predictors of MRI performance.

METHODS

A review of TIA and minor stroke patients evaluated at Veterans Affairs hospitals was conducted with regard to medical history, use of diagnostic imaging within 2 days of presentation, and in-hospital care variables. Chart abstraction was performed in a subset of hospitals to assess clinical variables not available in the administrative data.

RESULTS

A total of 7,889 patients with TIA/minor stroke were included. Overall, 6,694 patients (84.9%) had CT or MRI, with 3,396/6,694 (50.7%) having MRI. Variables that were associated with increased odds of CT performance were age >80 years, prior stroke, history of atrial fibrillation, heart failure, coronary artery disease, anxiety, and low hospital complexity, while blood pressure >140/90 mm Hg and high hospital complexity were associated with increased likelihood of MRI. Diplopia (87% had MRI, p = 0.03), neurologic consultation on the day of presentation (73% had MRI, p < 0.0001), and symptom duration of >6 hours (74% had MRI, p = 0.0009) were associated with MRI performance.

CONCLUSIONS

Within a national health system, about 40% of patients with TIA/minor stroke had MRI performed within 2 days. Performance of MRI appeared to be influenced by several patient and facility-level variables, suggesting that there has been partial acceptance of the previous guideline that endorsed MRI for patients with TIA.

Minor Stroke and Transient Ischemic Attack: Research and Practice

A majority of patients with ischemic stroke present with mild deficits for which aggressive management is not often pursued. Comprehensive work-up and appropriate intervention for minor strokes and transient ischemic attacks (TIAs) point toward better patient outcomes, lower costs, and fewer cases of disability. Imaging is a key modality to guide treatment and predict stroke recurrence. Patients with large vessel occlusions have been found to suffer worse outcomes and could benefit from intervention. Whether intravenous thrombolytic therapy decreases disability in minor stroke patients and whether acute endovascular intervention improves functional outcomes in patients with minor stroke and known large vessel occlusion remain controversial. Studies are ongoing to determine ideal antiplatelet therapy for stroke and TIA, while ongoing statin therapy, surgical management for patients with carotid stenosis, and anticoagulation for patients with atrial fibrillation have all been proven to decrease the rate of stroke recurrence and improve outcomes. This review summarizes the current evidence and discusses the standard of care for patients with minor stroke and TIA.