Early risk of stroke after a transient ischemic attack in patients with internal carotid artery disease

Outcomes of urgent carotid endarterectomy for stable and unstable acute neurologic deficits

OBJECTIVE

The aim of the study was to assess the outcomes of carotid endarterectomy (CEA) performed in an urgent setting on acutely symptomatic patients selected through a very simple protocol.

METHODS

From January 2002 to January 2012, 193 symptomatic patients underwent CEA. Of these, 90 presented with acute symptoms, and after a congruous carotid stenosis was identified, underwent urgent operations (group 1): 27 patients had transient ischemic attack (group 1A), 52 patients had mild to moderate stroke (group 1B), and 11 patients had stroke in evolution (group 1C). The remaining 103 patients with a nonrecent neurologic deficit were treated by elective surgery in the same period (group 2). End points were 30-day neurologic morbidity and mortality.

RESULTS

The median delay of urgent CEA (U-CEA) from deficit onset was 48 hours (interquartile range, 13-117 hours). Groups 1 and 2 were comparable in demographics. Acute patients showed a higher rate of stroke at presentation (70% vs 37%; P = .001) and of history of coronary artery disease (30% vs 13.5%; P = .007). Acute patients sustained six postoperative strokes (6.6%). Neurologic outcomes were correlated to clinical presentation: no strokes occurred in group 1A patients, and 5.8% group 1B patients and 27.3% group 1C patients had postoperative stroke (P < .01). Postoperative mortality was 4.4% for U-CEA: one fatal myocardial infarction, one intracranial hemorrhage, and two thromboembolic strokes. Elective patients sustained four postoperative strokes (3.9%), with one death (0.9%) as a consequence of hyperperfusion cerebral edema. U-CEAs performed ≤48 hours from symptom onset had a lower postoperative stroke rate than those performed >48 hours (4.4% vs 8.8%; P = .3). Among patients presenting with a stroke (group 1B), the National Institutes of Health Stroke Scale (NIHSS) assessment at discharge showed improvement in 79% (although only 25% had ≥4 points in reduction), stability in 17%, and deterioration in 4%. Patients with moderate stroke were slightly better in NIHSS improvement than those with mild stroke (median NIHSS variation at discharge, -3 vs -1; P = .001).

CONCLUSIONS

Our results with U-CEA confirm that this population has a higher risk profile compared with elective surgery. The type of acute presentation is correlated with perioperative risk. U-CEA was safe when performed on patients presenting with transient ischemic attack. An acceptable complication rate was achieved for patients with minor to moderate strokes. The poorest outcomes occurred in patients presenting with stroke in evolution: U-CEA in these patients should be offered with extreme caution, although we are aware that a conservative treatment may not grant a better prognosis.

Correlation between ABCD, ABCD2 scores and craniocervical artery stenosis in patients with transient ischemic attack

BACKGROUND AND PURPOSE

Craniocervical artery stenosis is an important etiology for transient ischemic attack (TIA). We hypothesized ABCD and ABCD2 scores can predict craniocervical artery stenosis in patients with TIA.

METHODS

ABCD and ABCD2 scores were calculated in a total of 479 consecutive first-ever TIA patients in Nanjing Stroke Registry Program and compared with angiographic imaging derived from MRI or invasive catheter-based angiography.

RESULTS

Overall craniocervical artery (O-CA) stenosis was found in 197 (41.1%) patients. Extracranial craniocervical artery (E-CA) and intracranial craniocervical artery (I-CA) stenosis was found in 101 (21.1%) and 110 (23%) cases, respectively. ABCD and ABCD2 scores with similar accuracy for O-CA (AUCABCD 0.71, AUCABCD2 0.70), E-CA (AUCABCD 0.72, AUCABCD2 0.72) and I-CA stenosis (AUCABCD 0.62, AUCABCD2 0.62) were both independent predictors for various categories of artery stenosis after being adjusted for non-ABCD2 parameters. The cut-off points were equally 4 in both predicting rules. For ABCD, sensitivity was 57.4, 65.3 and 52.7% and specificity 77.0, 70.4 and 67.5% for O-CA/E-CA/I-CA, respectively. For ABCD2, sensitivity was 61.9, 69.3 and 58.2% and specificity 72.3, 65.6 and 63.1%.

CONCLUSIONS

In patients with TIA, despite an association between ABCD and ABCD2 scores and underlying craniocervical artery stenosis, the clinical utility was limited by unsatisfactory sensitivity and specificity.

Carotid plaque hemorrhage on magnetic resonance imaging strongly predicts recurrent ischemia and stroke

Objective

There is a recognized need to improve selection of patients with carotid artery stenosis for carotid endarterectomy (CEA). We assessed the value of magnetic resonance imaging (MRI)-defined carotid plaque hemorrhage (MRIPH) to predict recurrent ipsilateral cerebral ischemic events, and stroke in symptomatic carotid stenosis.

Methods

One hundred seventy-nine symptomatic patients with ≥50% stenosis were prospectively recruited, underwent carotid MRI, and were clinically followed up until CEA, death, or ischemic event. MRIPH was diagnosed if the plaque signal intensity was >150% that of the adjacent muscle. Event-free survival analysis was done using Kaplan–Meier plots and Cox regression models controlling for known vascular risk factors. We also undertook a meta-analysis of reported data on MRIPH and recurrent events.

Results

One hundred fourteen patients (63.7%) showed MRIPH, suffering 92% (57 of 62) of all recurrent ipsilateral events and all but 1 (25 of 26) future strokes. Patients without MRIPH had an estimated annual absolute stroke risk of only 0.6%. Cox multivariate regression analysis proved MRIPH as a strong predictor of recurrent ischemic events (hazard ratio [HR] = 12.0, 95% confidence interval [CI] = 4.8–30.1, p < 0.001) and stroke alone (HR = 35.0, 95% CI = 4.7–261.6, p = 0.001). Meta-analysis of published data confirmed this association between MRIPH and recurrent cerebral ischemic events in symptomatic carotid artery stenosis (odds ratio = 12.2, 95% CI = 5.5–27.1, p < 0.00001).

Interpretation

MRIPH independently and strongly predicts recurrent ipsilateral ischemic events, and stroke alone, in symptomatic ≥50% carotid artery stenosis. The very low stroke risk in patients without MRIPH puts into question current risk–benefit assessment for CEA in this subgroup. ANN NEUROL 2013;73:774–784

Stroke recurrence in patients with recently symptomatic carotid stenosis and scheduled for carotid revascularization

BACKGROUND AND PURPOSE

Patients with symptomatic carotid stenosis (sCS) have a higher risk of stroke recurrence following the first ischaemic event. Guidelines recommend that patients undergo carotid revascularization (CR), preferably within 2 weeks of the event. We aimed to determine the rate of stroke recurrence during hospitalization in patients who were admitted to the hospital with an acute ischaemic event and who underwent CR for recently sCS.

METHODS

As part of the stroke registry in Schleswig-Holstein, Germany (QugSS2; Qualitätsgemeinschaft Schlaganfallversorgung in Schleswig-Holstein), over a 4.5-year period (starting 2007) all patients (N = 15,797) who were admitted to the hospital with an acute cerebral ischaemic event were included and prospectively evaluated.

RESULTS

A total of 597 (3.8%) patients (mean age, 71 ± 10 years; 30% women) underwent a CR. The median time between symptom onset and admission to hospitals was 6 h. During the mean hospitalization of 10 days, 30 patients (5%) suffered a stroke. The rates of stroke recurrence were higher, albeit non-significantly, in men compared with women (6% vs. 2.3%, respectively; P = 0.059), and in patients admitted with ischaemic stroke compared with patients admitted with transient ischaemic attack (6.1% vs. 2%, respectively; P = 0.052). The risk of stroke recurrence did not show any association with the other demographic and clinical parameters.

CONCLUSION

The rate of stroke recurrence was 5% in patients with recently sCS who scheduled for CR. This suggests that CR should be performed immediately after presenting event to prevent stroke recurrence.

Plaque features associated with increased cerebral infarction after minor stroke and TIA: a prospective, case-control, 3-T carotid artery MR imaging study

OBJECTIVES

The goal of this study was to determine whether a 3-T magnetic resonance imaging (MRI) protocol combining carotid atherosclerotic plaque and brain imaging can identify features of high-risk acutely symptomatic plaque that correlate with brain injury.

BACKGROUND

It has previously been demonstrated that, in asymptomatic patients, MRI can identify features of carotid plaque that are associated with stroke, such as the presence of a large lipid core. We hypothesized that the early phase (<7 days) after a cerebrovascular event, when risk of recurrence is highest, may be associated with particular plaque characteristics that associate with cerebral injury.

METHODS

Eighty-one patients (41 presenting acutely with transient ischemic attack [TIA] or minor stroke and 40 asymptomatic controls) underwent multicontrast carotid artery MRI on 2 separate occasions, each accompanied by diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) imaging of the brain.

RESULTS

Complex (American Heart Association [AHA] type VI) plaques were seen in 22 of 41 patients (54%) in the symptomatic group versus 8 of 40 (20%) in the asymptomatic group (p < 0.05). They were caused by intraplaque hemorrhage (34% vs. 18%; p = 0.08), surface rupture (24% vs. 5%; p = 0.03), or luminal thrombus (7% vs. 0%; p = 0.24). Noticeably, 17 of 30 (57%) cases of AHA type VI plaque were in vessels with <70% stenosis. At follow-up scanning (>6 weeks later), only 2 cases of symptomatic AHA type VI plaque showed evidence of full healing. The presence of fibrous cap rupture was associated with higher DWI brain injury at presentation and higher total cerebral FLAIR signal at follow-up (p < 0.05).

CONCLUSIONS

Early carotid wall MRI in patients experiencing minor stroke or TIA showed a higher proportion of "complex" plaques compared with asymptomatic controls; a majority were in arteries of <70% stenosis. Fibrous cap rupture was associated with increases in DWI and FLAIR lesions in the brain. Combined carotid plaque and brain MRI may aid risk stratification and treatment selection in acute stroke and TIA.

Cardioembolic stroke is frequent in late recurrence after transient ischemic attack

BACKGROUND

Transient ischemic attack (TIA) is often followed by a stroke episode. Differences between early and late recurrent stroke, however, have not been elucidated.

METHODS

We enrolled 133 consecutive patients with acute ischemic stroke who presented to our hospital and had previously been diagnosed with TIA. They were divided into 5 groups according to the interval between TIA and subsequent stroke: <48 hours (group 1); 48 hours to 1 week (group 2); 1 week to 1 month (group 3); 1 month to 3 months (group 4); and >3 months (group 5). Patients who underwent recurrent stroke within and after 1 week subsequent to TIA (the early and late recurrence groups, respectively) were compared with regard to clinical findings.

RESULTS

Of the 133 patients, 46 (34.6%) were in group 1, 29 (21.8%) in group 2, 23 (17.3%) in group 3, 18 (13.5%) in group 4, and 17 (12.8%) in group 5. Most of the noncardioembolic strokes were observed shortly after TIA, while the percentage of cardioembolic stroke remained high even after long post-TIA periods. The prevalence of atrial fibrillation (AF) was higher in the late recurrence group than in the early recurrence group (41.4% v 24.0%, P = .033). Among 42 patients with AF, 12 (28.6%) were newly diagnosed at the time of stroke.

CONCLUSIONS

The frequency of cardioembolic stroke did not decline as time after TIA passed. More than one quarter of AF patients had been asymptomatic before stroke, suggesting the need for repeated examinations to detect AF in patients with TIA of unknown etiology.

Recommendations for management of patients with carotid stenosis

Stroke is a one of the leading causes of morbidity and mortality in the world. Carotid atherosclerosis is recognized as an important factor in stroke pathophysiology and represents a key target in stroke prevention; multiple treatment modalities have been developed to battle this disease. Multiple randomized trials have shown the efficacy of carotid endarterectomy in secondary stroke prevention. Carotid stenting, a newer treatment option, presents a less invasive alternative to the surgical intervention on carotid arteries. Advances in medical therapy have also enabled further risk reduction in the overall incidence of stroke. Despite numerous trials and decades of clinical research, the optimal management of symptomatic and asymptomatic carotid disease remains controversial. We will attempt to highlight some of the pivotal trials already completed, discuss the current controversies and complexities in the treatment decision-making, and postulate on what likely lies ahead. This paper will highlight the complexities of decision-making optimal treatment recommendations for patients with symptomatic and asymptomatic carotid stenosis.

Risk of Recurrent Stroke before Carotid Endarterectomy: The ANSYSCAP Study

Background

Carotid endarterectomy yields greater risk reduction for ipsilateral ischemic stroke when performed within two-weeks of the last cerebrovascular symptom than when performed two-weeks or more after the last symptom. However, additional benefit might be gained if carotid endarterectomy is performed earlier than within two-weeks.

Aims

To investigate the 90-day risk of ipsilateral ischemic stroke recurrence after amaurosis fugax, retinal artery occlusion, transient ischemic attack, or minor ischemic stroke in patients with 50–99% carotid stenosis before carotid endarterectomy, with emphasis on the first 14 days.

Methods

Prospective cohort study. 230 consecutive patients with symptomatic 50–99% carotid stenosis (North American Symptomatic Carotid Endarterectomy Trial grading method) who underwent evaluation before carotid endarterectomy. Of these, 183 underwent carotid endarterectomy; the median delay to carotid endarterectomy was 29 days. Blood pressure lowering medication was used by 93% and lipid-lowering medication by 90%.

Results

The risk of ipsilateral ischemic stroke recurrence before carotid endarterectomy was 5·2% ( n = 12) within two-days, 7·9% ( n = 18) within seven-days, 11·2% ( n = 25) within 14 days, and 18·6% ( n = 33) within 90 days of the presenting event. The risk of ipsilateral ischemic stroke recurrence was higher if the presenting event was a stroke (adjusted hazard ratio 12·4, P = 0·015) or transient ischemic attack (adjusted hazard ratio 10·2, P = 0·026) compared with an amaurosis fugax.

Discussion

The risk of recurrent ipsilateral ischemic stroke was high within the first days of the presenting event. Many recurrences would likely have been avoided if carotid endarterectomy had been performed within the first days of the presenting event.

Management of patients with transient ischemic attack: insight from real-life clinical practice in Europe and the United States

OBJECTIVE

Transient ischemic attack (TIA) is a serious condition which should be considered on the same spectrum as other conditions involving brain ischemia. Efficient management of these patients is therefore critical. The aim of this research was to gain insights into 'real-world' global trends of the current management approaches for patients with suspected and diagnosed TIA, and highlight the unmet need and areas of improvement to ensure effective management of this patient group.

RESEARCH DESIGN AND METHODS

Tele-interviews were conducted with 120 physicians and five operational managers across France, Germany, Italy, Spain, UK, and the US including stakeholders from primary care group practice, those with hospital responsibilities (ER physician and Neurologists), or from home health agencies. Information from the interviewees regarding the management of patients with TIA (including entrance into the clinical pathway, diagnosis, and treatment) were obtained and analyzed qualitatively.

RESULTS

The majority of patients with suspected TIA were reported to enter the clinical pathway via the GP or ER, irrespective of country. Once initially seen, the neurologist then plays a central role in the diagnosis, treatment and follow-up of the patients. Although a number of tests are routinely employed, interviewees reported that streamlining and simplification of diagnosis, faster initiation of treatment, improved efficacy and fewer side-effects with treatment were needed for patients with suspected TIA. The study is designed to provide a directional indication of the current situation rather than strong, quantitative conclusions, given limitations of the small sample size and subjective nature of the data.

CONCLUSIONS

The importance of correct management of patients with TIA is becoming increasingly recognized by physicians. Improved education for patients regarding symptom recognition and severity is required along with a standardized diagnostic process. These would enable correct and fast diagnosis and initiation of treatment thereby reducing the risk of further events.

Asymptomatic and symptomatic carotid stenosis: an obsolete classification?

Since many years, clinical decisions about the management of patients with carotid stenosis have been based on the distinction between "asymptomatic" and "symptomatic" presentations. This was also reflected by the design of previous studies on the surgical versus conservative treatment and of current studies on interventional treatment versus surgery. Both terms, however, only address different phases of activity of the one and the same condition and blur the significant message that carotid stenosis is a most important marker of systemic atherosclerosis, which is accompanied by a much higher risk of cardiovascular events rather than stroke. As a consequence, early diagnosis and followup during best medical treatment, life-style management, regular cardiovascular assessment, and good control of all vascular risk factors should be recommended in all patients with carotid stenosis-whether identified in the long-lasting "silent" or short-lasting "vulnerable" period lasting only a few weeks after cerebral ischemia. Patients in this short time window benefit from additional carotid intervention, under the condition of an individually favorable benefit-risk ratio ("individual vulnerability").

ABCD2 Score and Large-Artery Atherosclerosis

BACKGROUND AND PURPOSE

Extracranial stenosis (ECS) or intracranial stenosis (ICS) are independent risk factors for stroke after transient ischemic attack (TIA). We examined the association of the age, blood pressure, clinical features, duration of symptoms and diabetes (ABCD2) score, a validated risk prediction model for stroke after TIA, and the presence of ICS or ECS.

METHODS

Vascular imaging and ABCD2 scores were obtained in a retrospective cohort of 77 consecutive patients diagnosed with TIA in a single center emergency department. The association between vascular stenosis and ABCD2 scores and how each related to clinical outcome was examined.

RESULTS

In all, 30 (39.2%) TIA patients had 37 stenotic lesions; 15 (40.5%) stenotic lesions were ICS and 22 (59.5%) stenotic lesions were ECS. A total of 7 patients (9.5%) had both ECS and ICS lesions. Patients with ABCD2 > 3 were more likely to have ICS (odds ratio [OR] = 6.25, confidence interval [CI] 1.39-32.44, P = .009) and ECS (OR = 5.25, CI = 1.56-17.66, P = .005). Of the 37 stenotic lesions, 21 (56.7%) were symptomatic; 4 (19.2%) of these had an ABCD2 ≤ 3. At 7 days, there were 4 ischemic strokes, 3 had previously demonstrated symptomatic stenotic lesions, and all had ABCD2 scores > 3.

CONCLUSIONS

Compared to patients in the low-risk ABCD2 scores, the patients with medium- to high-risk ABCD2 scores are more likely to have symptomatic and asymptomatic vascular stenotic lesions. However, 1 in 5 patients with low-risk ABCD2 score has symptomatic stenotic lesions, indicating ABCD2 score does not identify all patients with symptomatic stenotic lesions.

Clinical features and functional outcome of stroke after transient ischemic attack

BACKGROUND

Transient ischemic attacks (TIAs) greatly increase the risk of stroke, but few reports have examined subsequent stroke in patients with history of TIA.

METHODS

This retrospective, hospital-based study included 506 consecutive patients with acute ischemic stroke who were admitted to our hospital. The clinical features and prognosis were compared between patients with and without TIA. Multiple logistic regression analysis was also performed to identify predictors for poor outcome.

RESULTS

Of 506 patients, 114 (22.5%) had a history of TIA. Compared to patients without previous TIAs (non-TIA group), patients with previous TIAs (TIA group) were significantly more likely to have hypertension (76.3% vs 64.3%; P = .016), dyslipidemia (57.0% vs 41.1%; P = .003), chronic kidney disease (28.1% v 15.1%; P = .001), intracranial major artery stenosis (51.8% vs 36.2%; P = .018), and large artery atherothrombosis (43.9% vs 28.3%; P = .002). There was no difference in the previous use of antithrombotic medications between the groups (36.0% vs 35.2%; P = .881). Although stroke severity on admission was similar, poor functional outcome (modified Rankin Scale score ≥4) was significantly more frequent in the TIA group, and history of TIA was an independent determinant of unfavorable outcome on multiple logistic regression analysis (odds ratio 1.46; 95% confidence interval 1.02-2.10; P = .041).

CONCLUSIONS

Atherothrombotic stroke with concomitant vascular risk factors were more frequent in the stroke patients with than without previous TIA. Antithrombotic therapy was conducted only in one-third of the patients even after TIA. The stroke patients with history of TIA were at great risk of disabling stroke.

Organized outpatient care: stroke prevention clinic referrals are associated with reduced mortality after transient ischemic attack and ischemic stroke

BACKGROUND AND PURPOSE

Organized inpatient stroke care decreases mortality and morbidity irrespective of patient age, stroke severity, or stroke subtype. Limited information is available on whether organized outpatient care models such as stroke prevention clinics (SPC) improve outcomes after a transient ischemic attack or ischemic stroke. We compared 1-year mortality and stroke readmission in patients with transient ischemic attack or ischemic stroke referred versus not referred to an SPC.

METHODS

This was a retrospective cohort study including 16,468 consecutive patients with ischemic stroke or transient ischemic attack who were seen in the emergency department or admitted to a hospital between July 1, 2003 and March 31, 2008 at registry stroke centers (n=12) in the province of Ontario. Cox proportional hazards models and propensity score-matched analyses were used to evaluate 1-year mortality and readmission.

RESULTS

One-year mortality rates were lower in those referred to SPCs compared with those not referred, even after adjustment for age, sex, ethnic origin, income, comorbid conditions, stroke symptoms and severity, receipt of thrombolysis, stroke unit care, discharge destination, and functional status at discharge (adjusted hazard ratio [HR], 0.67; 95% CI, 0.60-0.75). Survival analysis after propensity matching showed a 26% reduction in 1-year mortality (HR, 0.74; 95% CI, 0.65-0.84). There were no significant differences in 1-year readmission rates in those referred versus not referred to SPCs.

CONCLUSIONS

Referral to an SPC is associated with a one-quarter reduction in mortality after ischemic stroke or transient ischemic attack. This supports the argument that outpatient stroke units may prove as effective as their inpatient counterparts.

Preprocedural imaging strategies in symptomatic carotid artery stenosis

BACKGROUND

The benefit of carotid endarterectomy (CEA) over best medical therapy was established using intra-arterial angiography (IAA) for patient selection. Its cost, availability, and risk together with the emergence of newer imaging modalities have led to its replacement in the routine assessment of internal carotid artery (ICA) stenosis. The relative performance of these methods should dictate the optimum imaging strategy in symptomatic patients.

METHODS

A previous meta-analysis (NIHR Health Technology Assessment Programme) was reviewed. Medline and PubMed search was performed for relevant publications since 2006 together with a review of the references in retrieved publications.

RESULTS

Compared to IAA, the sensitivity and specificity for noninvasive imaging of a ≥70% to 99% ICA stenosis are duplex ultrasound (DUS): 0.89 (0.85-0.92) and 0.84 (0.77-0.89); time-of-flight magnetic resonance angiography (TOF-MRA): 0.88 (0.82-0.92) and 0.84 (0.76-0.97); contrast-enhanced MRA (CE-MRA): 0.94 (0.88-0.97) and 0.93 (0.89-0.96); and computed tomography angiography: 0.77 (0.68-0.84) and 0.95 (0.91-0.97), respectively. A policy of initial DUS followed by confirmatory CE-MRA best matches patient selection by arteriography. Single modality imaging for 50% to 69% ICA stenoses suggests reduced reliability resulting in more inappropriate operations.

CONCLUSIONS

DUS is the optimum screening tool due to its sensitivity and specificity, availability, and low cost. When CEA appears indicated, confirmatory imaging with CE-MRA is the most reliable and cost-effective method of investigation.

The ABCD and ABCD2 Scores and the Risk of Stroke following a TIA: A Narrative Review

The California, ABCD, and ABCD2 risk scores (ABCD system) were developed to help stratify short-term stroke risk in patients with TIA (transient ischemic attack). Beyond this scope, the ABCD system has been extensively used to study other prognostic information such as DWI (diffusion-weighted imaging) abnormalities, large artery stenosis, atrial fibrillation and its diagnostic accuracy in TIA patients, which are independent predictors of subsequent stroke in TIA patients. Our comprehensive paper suggested that all scores have and equivalent prognostic value in predicting short-term risk of stroke; however, the ABCD2 score is being predominantly used at most centers. The majority of studies have shown that more than half of the strokes in the first 90 days, occur in the first 7 days. The majority of patients studied were predominantly classified to have a higher ABCD/ABCD2 > 3 scores and were particularly at a higher short-term risk of stroke or TIA and other vascular events. However, patients with low risk ABCD2 score < 4 may have high-risk prognostic indicators, such as diffusion weighted imaging (DWI) abnormalities, large artery atherosclerosis (LAA), and atrial fibrillation (AF). The prognostic value of these scores improved if used in conjunction with clinical information, vascular imaging data, and brain imaging data. Before more data become available, the diagnostic value of these scores, its applicability in triaging patients, and its use in evaluating long-term prognosis are rather secondary; thus, indicating that the primary significance of these scores is for short-term prognostic purposes.

National Stroke Association recommendations for systems of care for transient ischemic attack

Transient ischemic attacks (TIAs) are common and portend a high short-term risk of stroke. Evidence-based recommendations for the urgent evaluation and treatment of patients with TIA have been published. However, implementation of these recommendations reliably and consistently will require changes in the systems of care established for TIA. The National Stroke Association convened a multidisciplinary panel of experts to develop recommendations for the essential components of systems of care at hospitals to improve the quality of care provided to patients with TIA. The panel recommends that hospitals establish standardized protocols to assure rapid and complete evaluation and treatment for patients with TIA, with particular attention to urgency and close observation in patients at high risk of stroke.

Heart disease and stroke statistics--2011 update: a report from the American Heart Association

Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay public, and many others who seek the best national data available on disease morbidity and mortality and the risks, quality of care, medical procedures and operations, and costs associated with the management of these diseases in a single document. Indeed, since 1999, the Statistical Update has been cited more than 8700 times in the literature (including citations of all annual versions). In 2009 alone, the various Statistical Updates were cited ≈1600 times (data from ISI Web of Science). In recent years, the Statistical Update has undergone some major changes with the addition of new chapters and major updates across multiple areas. For this year’s edition, the Statistics Committee, which produces the document for the AHA, updated all of the current chapters with the most recent nationally representative data and inclusion of relevant articles from the literature over the past year and added a new chapter detailing how family history and genetics play a role in cardiovascular disease (CVD) risk. Also, the 2011 Statistical Update is a major source for monitoring both cardiovascular health and disease in the population, with a focus on progress toward achievement of the AHA’s 2020 Impact Goals. Below are a few highlights from this year’s Update.

Rationale and design of a randomized, double-blind trial comparing the effects of a 3-month clopidogrel-aspirin regimen versus aspirin alone for the treatment of high-risk patients with acute nondisabling cerebrovascular event

BACKGROUND

Acute nondisabling cerebrovascular events are common and often portend a disabling stroke. Aspirin is the only antiplatelet agent to have been studied in patients presenting acutely with a cerebrovascular event, but the effect is modest and is reduced by a small increased risk of intracerebral hemorrhage. Treatment with the combination of clopidogrel and aspirin might be beneficial when taken soon after a transient ischemic attack (TIA) or minor stroke. The CHANCE trial is a randomized, double-blind, multicenter, placebo-controlled trial to test an aggressive antiplatelet regimen in acute minor stroke or TIA.

DESIGN

The study will randomize 5,100 Chinese patients with acute TIA or minor stroke to receive a 3-month regimen of clopidogrel initiated with a loading dose of 300 mg followed by 75 mg/d, combined with aspirin 75 mg/d during the first 21 days, or a 3-month regimen of aspirin 75 mg/d alone. The primary efficacy end point is percentage of patients with any stroke (ischemic or hemorrhage) at 3 months. Study visits will be performed on the day of randomization, at day 21, and at day 90.

SUMMARY

CHANCE will determine whether clopidogrel combined with aspirin can prevent more strokes after acute minor stroke or TIA compared with aspirin alone-with an acceptable risk profile.

Association between biomechanical structural stresses of atherosclerotic carotid plaques and subsequent ischaemic cerebrovascular events--a longitudinal in vivo magnetic resonance imaging-based finite element study

BACKGROUND

High-resolution magnetic resonance (MR) imaging has been used for MR imaging-based structural stress analysis of atherosclerotic plaques. The biomechanical stress profile of stable plaques has been observed to differ from that of unstable plaques; however, the role that structural stresses play in determining plaque vulnerability remains speculative.

METHODS

A total of 61 patients with previous history of symptomatic carotid artery disease underwent carotid plaque MR imaging. Plaque components of the index artery such as fibrous tissue, lipid content and plaque haemorrhage (PH) were delineated and used for finite element analysis-based maximum structural stress (M-C Stress) quantification. These patients were followed up for 2 years. The clinical end point was occurrence of an ischaemic cerebrovascular event. The association of the time to the clinical end point with plaque morphology and M-C Stress was analysed.

RESULTS

During a median follow-up duration of 514 days, 20% of patients (n = 12) experienced an ischaemic event in the territory of the index carotid artery. Cox regression analysis indicated that M-C Stress (hazard ratio (HR): 12.98 (95% confidence interval (CI): 1.32-26.67, p = 0.02), fibrous cap (FC) disruption (HR: 7.39 (95% CI: 1.61-33.82), p = 0.009) and PH (HR: 5.85 (95% CI: 1.27-26.77), p = 0.02) are associated with the development of subsequent cerebrovascular events. Plaques associated with future events had higher M-C Stress than those which had remained asymptomatic (median (interquartile range, IQR): 330 kPa (229-494) vs. 254 kPa (166-290), p = 0.04).

CONCLUSIONS

High biomechanical structural stresses, in addition to FC rupture and PH, are associated with subsequent cerebrovascular events.

Prognostic value of the ABCD2 score beyond short-term follow-up after transient ischemic attack (TIA)--a cohort study

BACKGROUND

Transient ischemic attack (TIA) patients are at a high vascular risk. Recently the ABCD2 score was validated for evaluating short-term stroke risk after TIA. We assessed the value of this score to predict the vascular outcome after TIA during medium- to long-term follow-up.

METHODS

The ABCD2 score of 176 TIA patients consecutively admitted to the Stroke Unit was retrospectively calculated and stratified into three categories. TIA was defined as an acute transient focal neurological deficit caused by vascular disease and being completely reversible within 24 hours. All patients had to undergo cerebral MRI within 5 days after onset of symptoms as well as extracranial and transcranial Doppler and duplex ultrasonography. At a median follow-up of 27 months, new vascular events were recorded. Multivariate Cox regression adjusted for EDC findings and heart failure was performed for the combined endpoint of cerebral ischemic events, cardiac ischemic events and death of vascular or unknown cause.

RESULTS

Fifty-five patients (32.0%) had an ABCD2 score < or = 3, 80 patients (46.5%) had an ABCD2 score of 4-5 points and 37 patients (21.5%) had an ABCD2 score of 6-7 points. Follow-up data were available in 173 (98.3%) patients. Twenty-two patients (13.8%) experienced an ischemic stroke or TIA; 5 (3.0%) a myocardial infarction or acute coronary syndrome; 10 (5.7%) died of vascular or unknown cause; and 5 (3.0%) patients underwent arterial revascularization. An ABCD2 score > 3 was significantly associated with the combined endpoint of cerebral or cardiovascular ischemic events, and death of vascular or unknown cause (hazard ratio (HR) 4.01, 95% confidence interval (CI) 1.21 to 13.27). After adjustment for extracranial ultrasonographic findings and heart failure, there was still a strong trend (HR 3.13, 95% CI 0.94 to 10.49). Whereas new cardiovascular ischemic events occurred in 9 (8.3%) patients with an ABCD2 score > 3, this happened in none of the 53 patients with a score < or = 3.

CONCLUSIONS

An ABCD2 score > 3 is associated with an increased general risk for vascular events in the medium- to long-term follow-up after TIA.

MR plaque imaging of the carotid artery

Atherosclerotic carotid plaque represents a major cause of cerebral ischemia. The detection of vulnerable plaque is important for preventing future cardiovascular events. The key factors in advanced plaque that are most likely to lead to patient complications are the condition of the fibrous cap, the size of the necrotic core and hemorrhage, and the extent of inflammatory activity within the plaque. Magnetic resonance (MR) imaging has excellent soft tissue contrast and can allow for a more accurate and objective estimation of carotid wall morphology and plaque composition. Recent advances in MR imaging techniques have permitted serial monitoring of atherosclerotic disease evolution and the identification of intraplaque risk factors for accelerated progression. The purpose of this review article is to review the current state of techniques of carotid wall MR imaging and the characterization of plaque components and surface morphology with MR imaging, and to describe the clinical practice of carotid wall MR imaging for the determination of treatment plan.

Predicting recurrent stroke after minor stroke and transient ischemic attack

The risk of a subsequent stroke following an acute transient ischemic attack or minor stroke is high, with 90-day risk at approximately 10%. Identification of those patients at the highest risk for recurrent stroke following a transient ischemic attack or minor stroke may allow risk-specific management strategies to be implemented, such as hospital admission with expedited work-up for those at high risk and emergency room discharge for those at low risk. Predictors of recurrent stroke, including the ABCD2 score, brain imaging and the stroke mechanism, are reviewed in this article, with a focus on recent literature. An emphasis is placed on the importance of early imaging of the brain parenchyma (diffusion-weighted imaging) and vascular imaging to identify patients at high risk for recurrence. The need for identification of the cause of the initial event, allowing therapies to be tailored to the individual patient, is discussed.