Ulcerated atherosclerotic plaques in the thoracic aorta are associated with cryptogenic stroke: a multiplane transesophageal echocardiographic study

Three-dimensional transesophageal echocardiographic evaluation of aortic plaque after cerebrovascular event

INTRODUCTION AND OBJECTIVES

Transesophageal echocardiography (TEE) is crucial in order to assess aortic anatomy after stroke. Although routinely used to assess cardiovascular anatomy and function, three-dimensional echocardiography (3D TEE) is less used for aortic evaluation. We thus sought to assess prospectively whether additional information on aortic plaque morphology could be obtained with 3D TEE after an ischemic stroke.

METHODS

Patients within one week of a stroke (confirmed by brain computed tomography/magnetic resonance) underwent TEE and 3D findings were compared with two-dimensional (2D) (aorta plaque number, dimensions, area and the presence of debris and ulcerations). Patients were followed for two years for death or a new stroke.

RESULTS

We assessed 78 patients, 43 (55%) male, aged 62±14 years old, 92% in sinus rhythm. Aortic atheroma was found mainly in the descending aorta (50%); plaque thickness was similar for 2D TEE (0.29±0.03 cm) and 3D TEE (0.29±0.04 cm), whereas plaque area was slightly increased for 3D measurements (0.24±0.02 cm² versus 0.37±0.03 cm² respectively, p<0.05), with a strong correlation found both for aortic plaque thickness (r=0.91) and area (r=0.80) measurements. While aortic debris were equally seen with both techniques, 3D TEE defines the presence of ulcerations (six ulcerations unseen with 2D TEE better, p=0.03). There were 11 events (six deaths and five new strokes) during follow-up, unrelated to plaque characteristics.

CONCLUSION

To evaluate aortic plaque morphology, 3D TEE is superior to 2D TEE due to improved detection of ulcerated aortic plaque; this might provide additional information in patients after ischemic stroke.

Vessel wall MR imaging of aortic arch, cervical carotid and intracranial arteries in patients with embolic stroke of undetermined source: A narrative review

Despite advancements in multi-modal imaging techniques, a substantial portion of ischemic stroke patients today remain without a diagnosed etiology after conventional workup. Based on existing diagnostic criteria, these ischemic stroke patients are subcategorized into having cryptogenic stroke (CS) or embolic stroke of undetermined source (ESUS). There is growing evidence that in these patients, non-cardiogenic embolic sources, in particular non-stenosing atherosclerotic plaque, may have significant contributory roles in their ischemic strokes. Recent advancements in vessel wall MRI (VW-MRI) have enabled imaging of vessel walls beyond the degree of luminal stenosis, and allows further characterization of atherosclerotic plaque components. Using this imaging technique, we are able to identify potential imaging biomarkers of vulnerable atherosclerotic plaques such as intraplaque hemorrhage, lipid rich necrotic core, and thin or ruptured fibrous caps. This review focuses on the existing evidence on the advantages of utilizing VW-MRI in ischemic stroke patients to identify culprit plaques in key anatomical areas, namely the cervical carotid arteries, intracranial arteries, and the aortic arch. For each anatomical area, the literature on potential imaging biomarkers of vulnerable plaques on VW-MRI as well as the VW-MRI literature in ESUS and CS patients are reviewed. Future directions on further elucidating ESUS and CS by the use of VW-MRI as well as exciting emerging techniques are reviewed.

Coexisting of aortic arch atheroma and atrial fibrillation for short-term recurrence and poor functional outcome in acute stroke

BACKGROUND AND PURPOSE

Multiple embolic sources are sometimes observed simultaneously in patients with embolic stroke. The present study investigated the effects of coexisting aortic arch atheroma ≥ 4 mm thick and atrial fibrillation (AF) on short-term stroke recurrence and functional outcome.

METHODS

Transesophageal echocardiography (TEE) was performed in consecutive embolic stroke patients, and 395 patients were classified into 4 groups according to the presence of aortic arch atheroma ≥ 4 mm thick and AF: AF - /ARCH - group, AF + /ARCH - group, AF - /ARCH + group, and AF + /ARCH + group. In accordance with these 4 groups, we evaluated stroke recurrence and all-cause death for 3 months after stroke onset, and also evaluated the 3-month functional outcome using the modified Rankin scale (mRS).

RESULTS

Among the 128 AF patients, 39.1% also had aortic arch atheroma ≥ 4 mm thick. Of the 395 enrolled cases, the AF + /ARCH + group showed the highest frequencies of stroke recurrence and all-cause death during 3 months after onset. On multivariate analysis, stroke recurrence or all-cause death during 3 months after onset was relatively more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.34; 95% CI, 0.82-6.69; p = 0.11), but that was not statistically significant, and poor functional outcome (mRS score 3-6) at 3 months was significantly more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.59; 95% CI, 1.08-6.24; p = 0.0339).

CONCLUSIONS

Aortic arch atheroma concomitant with AF is not rare and appears associated with increased risks of stroke recurrence and poor functional outcome.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods-bright (B)-mode US plus Doppler mode-provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray-Weale standardization-echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation-the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

Antithrombotic Therapy for Stroke Patients with Cardiovascular Disease

Prevention of ischemic stroke relies on the use of antithrombotic medications comprising antiplatelet agents and anticoagulation. Stroke risk is particularly high in patients with cardiovascular disease. This review will focus on the role of antithrombotic therapies in the context of different types of cardiovascular disease. We will discuss oral antiplatelet medications and both IV and parental anticoagulants. Different kinds of cardiovascular disease contribute to stroke via distinct pathophysiological mechanisms, and the optimal treatment for each varies accordingly. We will explore the mechanism of stroke and evidence for antithrombotic therapy in the following conditions: atrial fibrillation, prosthetic heart values (mechanical and bioprosthetic), aortic arch atherosclerosis, congestive heart failure (CHF), endocarditis (infective and nonbacterial thrombotic endocarditis), patent foramen ovale (PFO), left ventricular assist devices (LVAD), and extracorporeal membrane oxygenation (ECMO). While robust data exist for antithrombotic use in conditions such as atrial fibrillation, optimal treatment in many situations remains under active investigation.

Left Atrial Appendage Flow Velocity and Multiple Infarcts in Cryptogenic Stroke

BACKGROUND

To validate the hypothesis that cryptogenic stroke with multiple infarcts included embolic stroke due to left atrial appendage (LAA) dysfunction, the present retrospective observational study was aimed to clarify the association between LAA flow velocity (LAA-FV) and multiple infarcts in patients with cryptogenic stroke.

METHODS

From consecutive patients with cryptogenic stroke admitted to our hospital within 7 days after onset, patients without brain magnetic resonance imaging (MRI) on admission or without transesophageal echocardiography (TEE) during acute hospitalization were excluded, and the remaining patients were enrolled. Multiplicity of fresh infarcts was assessed using diffusion-weighted images from brain MRI. LAA-FV was defined as LAA peak emptying flow velocity on TEE.

RESULTS

Of 786 enrolled patients, 522 patients (66%) had a single infarct, and the remaining 264 patients (34%) had multiple infarcts. The percentage of multiple infarcts decreased with increasing quartiles of LAA-FV (p for trend <0.001). The adjusted odds ratio for multiple infarcts decreased with increasing quartiles of LAA-FV (adjusted odds ratio in the fourth quartile, 0.39; 95% confidence interval, 0.25-0.60; compared with the first quartile). LAA-FV as a continuous variable was negatively associated with multiple infarcts (adjusted odds ratio per 10 cm/s, 0.87; 95% confidence interval, 0.81-0.92).

CONCLUSIONS

Reduced LAA-FV on TEE was associated with multiple infarcts in patients with cryptogenic stroke. The present findings indicate that cryptogenic stroke with multiple infarcts includes embolic stroke due to LAA dysfunction.

Antispasmodic Effect of Blackcurrant (Ribes nigrum L.) Juice and Its Potential Use as Functional Food in Gastrointestinal Disorders

OBJECTIVE

The purpose of this study was to investigate the relaxative effects of blackcurrant juice on the gastrointestinal smooth muscle in vitro.

MATERIALS AND METHODS

Berries of the blackcurrant cultivar Ometa were used for the preparation of the juice used. The spasmolytic activity of blackcurrant juice was tested on rat ileum isolated from male Wistar rats by monitoring its influence on spontaneous contractions, as well as contractions induced by potassium chloride (KCl), barium chloride (BaCl2), calcium chloride (CaCl2), and acetylcholine (Ach). The results are expressed as the mean ± standard deviation obtained in 6 measurements and statistical significance was determined by the Student t test, with p < 0.05 taken as significant.

RESULTS

The blackcurrant cultivar Ometa significantly reduced the frequency and the amplitude of spontaneous contractions (57.94 ± 3.44%) and Ach-induced contractions (42.74 ± 5.36%; p < 0.05) of the isolated rat ileum. Cumulative concentrations (0.01-3 mg/mL) of the Ometa juice also reduced contractions of the isolated rat ileum stimulated by KCl (51.46 ± 6.87%), CaCl2 (57.54 ± 6.47%), and BaCl2 (58.54 ± 10.55%). The inhibitory effects of the juice were proportional to the applied concentration.

CONCLUSION

The antispasmodic effect of Ometa cultivar shows that common gastrointestinal disorders could be treated by the functional food.

A Novel Evaluation for Predicting Aortic Complicated Lesions Using Calcification on Chest X-ray

BACKGROUND

The aorta is a significant source of cerebral thromboembolisms. Aortic complicated lesions (ACLs) are key findings on transesophageal echocardiography (TEE) for assessing aortic sources of emboli to the brain. TEE is sometimes avoided due to its invasiveness. However, few reports have examined alternative methods for predicting ACLs. We investigated relationships between aortic arch calcification (AAC) on chest X-ray and ACLs.

METHODS

Participants comprised 300 patients with acute ischemic stroke or transient ischemic attack who underwent TEE for the evaluation of the aortic arch and heart. A postero-anterior plain chest X-ray in the recumbent position was evaluated on admission for each patient. AAC was evaluated using 4 grades (0-3) and "AAC thickness" defined as the distance from the inner margin of the most distant AAC to the outer margin of the aortic vessel wall. ACLs were defined by intima-media thickness (IMT) ≥4.0 mm or presence of ulcerated or mobile plaques. Carotid maximum IMT on ultrasonography was also evaluated. Comparison of the diagnostic ability to predict ACL was performed between AAC grades and AAC thickness or AAC thickness and carotid maximum IMT using the Delong method.

RESULTS

ACLs were identified in 71 patients (23.7%), including ACLs with ulcerated plaques in 24 (8.0%) and ACLs with mobile plaques in 9 (3.0%). Plaque thickness was greater in higher AAC grades or higher quartiles of AAC thickness (p for trend <0.001 each). The Cochran-Armitage test showed that both higher AAC grade and higher quartile of AAC thickness were significantly associated with the presence of ACLs, as well as the presence of ulcerated or mobile plaques (p for trend < 0.001 each). Receiver-operating characteristic (ROC) analysis showed optimal cut-off values for AAC thickness of 5.6 mm for ACLs and 6.0 mm for ulcerated or mobile plaques. Multivariate logistic regression revealed a higher grade of AAC (grades 2-3) and AAC thickness (≥6 mm) as significantly associated with ACLs and ulcerated or mobile plaques (p < 0.001 each). ROC curve comparisons showed that AAC thickness offered a better marker of ACLs than AAC grade (p = 0.019), although no significant difference was evident between AAC thickness and carotid maximum IMT (p = 0.567).

CONCLUSIONS

AAC on chest X-ray, evaluated by both AAC grade and AAC thickness to the outer aortic vessel wall, was significantly associated with ACLs on TEE. AAC thickness was suggested as more useful than AAC grade and equivalent to carotid IMT in predicting ACLs.

Risk Factors of Aortic Plaque Progression Evaluated by Long-Term Follow-Up Data With Transesophageal Echocardiography

There are few longitudinal data regarding aortic plaque. This study aimed to examine chronological changes in aortic plaques with transesophageal echocardiography (TEE), and to clarify the risk factors of aortic plaque progression. Among 2,675 consecutive patients who underwent TEE, we retrospectively investigated 252 patients who underwent follow-up TEE with an interval >3 years. The thickness and morphology of aortic plaques were examined. Chronological changes in aortic plaques were investigated by comparing baseline and follow-up TEE. Clinical factors, laboratory data, and medications were evaluated. Among 252 study patients, the grade of aortic plaques was unchanged in 213 (group U), but progression was observed in 32 (group P) and regression in 7 patients (group R). Patients in group P were older; they had a higher prevalence of coronary artery disease, hypertension, smoking habit, and moderate or severe plaque at baseline TEE; more patients were using statins and no warfarin; and they had higher creatinine levels than those in group U. In multivariate analysis, moderate or severe plaques at baseline TEE were the strongest predictor of plaque progression. Among 50 patients who showed moderate or severe plaque at baseline TEE, smoking habit and no anticoagulation therapy were predictors of plaque progression. In conclusion, aortic plaques should be followed up using TEE in patients with moderate or severe plaque at baseline TEE.

Embolic Strokes of Unknown Source and Cryptogenic Stroke: Implications in Clinical Practice

Up to a third of strokes are rendered cryptogenic or of undetermined etiology. This number is specifically higher in younger patients. At times, inadequate diagnostic workups, multiple causes, or an under-recognized etiology contributes to this statistic. Embolic stroke of undetermined source, a new clinical entity particularly refers to patients with embolic stroke for whom the etiology of embolism remains unidentified despite through investigations ruling out established cardiac and vascular sources. In this article, we review current classification and discuss important clinical considerations in these patients; highlighting cardiac arrhythmias and structural abnormalities, patent foramen ovale, paradoxical sources, and potentially under-recognized, vascular, inflammatory, autoimmune, and hematologic sources in relation to clinical practice.

Extract from Ribes nigrum leaves in vitro activates nitric oxide synthase (eNOS) and increases CD39 expression in human endothelial cells

The aim of the present study was to evaluate whether blackcurrant leaf extract (BLE) modulates endothelium antithrombotic function, namely increases the expression/activity of ADPase (CD39) and augments the production of nitric oxide in human umbilical vein endothelial cells (HUVEC). It was found that BLE with proanthocyanidins (60 % of the total polyphenol content) increased the CD39-positive endothelial cell fraction (up to 10 % for 2.5 μg/ml, and up to 33 % for 15 μg/ml, p < 0.05 or less) in a concentration-dependent manner, and enhanced endothelial nitric oxide synthase (eNOS) activation (T495 phosphorylation decreased by 31 ± 6 % for 2.5 μg/ml and 48 ± 6 % for 15 μg/ml; S1177 phosphorylation increased by 13 ± 3 % for 2.5 μg/ml and 18 ± 7 % for 15 μg/ml, compared to untreated cells, p < 0.05 or less). Additionally, incubation for 24 or 48 h with BLE at a lower range of polyphenol concentrations, significantly increased cell viability with a maximal effect at 2.5 μg/ml (viability increased by 24.8 ± 1.0 % for 24 h and by 32.5 ± 2.7 % for 48-h time incubation, p < 0.0001). The increased CD39 expression and the increased eNOS activation in HUVEC can be regarded as the beneficial markers of the improvement of antiplatelet action of endothelial cells. Unexpectedly, these assumptions were not confirmed in the experimental model of platelet-endothelial cell interactions. These observations lead to the conclusion that BLE may improve endothelial cell viability at low physiological concentrations without affecting the antiplatelet action of endothelium.

Transoesophageal echocardiography of aortic atherosclerosis: the additive value of three-dimensional over two-dimensional imaging

AIMS

Complex aortic atherosclerotic plaques (AAPs) carry a significant risk of embolism. Currently, two-dimensional (2D) transoesophageal echocardiography (TOE) is the principal diagnostic tool of AAPs. However, we hypothesized that the data obtained from three-dimensional (3D) imaging may improve AAPs' spatial assessment.

METHODS AND RESULTS

The study included 67 patients (aged 70 ± 15 years, 35 men), who had routine TEE studies. The thoracic aorta was studied from arch to distal descending aorta, using the x-plane mode (simultaneous short- and long-axis views). If focal intimal thickening (suggestive of AAP) was detected, the 3D zoom algorithm was exercised on the specific site with further post-processing on a Q-lab workstation to measure its thickness in the X, Y, and Z dimensions. The AAP contour was defined qualitatively as regular or irregular in each mode. A total of 100 AAPs were investigated. The AAP thickness estimation was significantly greater in the 3D mode than in the 2D mode (0.51 ± 0.33 vs. 0.28 ± 0.20 cm, P < 0.001). The rate of complex AAPs (defined by AAP thickness of ≥4 mm) was two-fold higher with 3D imaging than with 2D imaging (27% with 2D imaging alone vs. 53% with the addition of 3D imaging). The rate of irregular AAPs increased from 29 to 65% when assessed with 3D imaging compared with 2D imaging.

CONCLUSION

This study has shown a significant difference in the estimation of AAPs between 2D and 3D TEE. The significant shift to a more complex AAPs profile may suggest that 3D imaging is preferable for the assessment of aortic atherosclerosis burden.

Aortic arch atheroma and the risk of stroke: a meta-analysis

BACKGROUNDS AND OBJECTIVES

Epidemiological studies have suggested that aortic atheroma may play a role in cerebral embolization; however, no meta-analysis was conducted to evaluate the relationship between aortic atheroma and risk of stroke. The aim of this study was to investigate the association between the presence of aortic atheroma and risk of stroke.

METHODS

We performed a comprehensive search of observational studies reporting the relationship between the presence of aortic atheroma and stroke using the PubMed, EMbase, the China National Knowledge Infrastructure database (CNKI), Chinese Technical Periodicals (VIP), and WanFang Data databases. Two reviewers independently assessed the eligibility and extracted data from the included studies. We performed the meta-analysis to estimate the strength of the association according to Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline and assessed the study quality by the Newcastle-Ottawa Scale (NOS).

RESULTS

We identified 12 eligible studies with 3918 participants. The scores of the NOS of the included studies ranged from 5 to 9. The pooled estimate of strength of the association between the presence of aortic atheroma and stroke was statistical significant (OR = 3.93, 95%CI 2.86 to 5.40). In subgroup analysis according to plaques' morphology, complex aortic atheroma had significantly higher (OR = 5.90, 95%CI 4.14 to 8.41) risk of stroke than protruding atheroma (OR = 3.75, 95%CI 3.05 to 4.61).

CONCLUSIONS

This study indicated that aortic atheroma significantly increased the risk of stroke by about four times. Patients with complex aortic atheroma have a higher risk of stroke than protruding atheroma.

Aortic arch atherosclerosis in ischaemic stroke of unknown origin affects prognosis

Background

Cerebral infarction of unknown origin at admission accounts for half of all cerebral infarction cases in some institutions. However, the factors associated with cerebral infarction prognosis have not been sufficiently examined. Here, we investigated whether aortic arch plaques (AAPs) on transoesophageal echocardiography (TOE) were associated with the prognosis of cerebral infarction of unknown origin at admission.

Methods

Of 571 patients who were hospitalised between June 2009 and September 2011, 149 (age: 67 ± 14 years; 95 men) with cerebral infarctions of unknown origin at admission underwent TOE and were enrolled in this study. We examined their clinical characteristics, the incidence of intermittent atrial fibrillation detected on 24-hour electrocardiography, and the echographic findings of the carotid artery in the hospital. A poor prognostic outcome was defined as a modified Rankin Scale score of ≥3 after 90 days.

Results

In all, 110 patients (74%) showed good prognoses and 39 patients (26%) showed poor outcomes. A National Institutes of Health Stroke Scale score of >6 on admission [odds ratio (OR) = 6.77; 95% confidence interval (CI): 2.59-18.8; p < 0.001] and AAPs of ≥4 mm (OR = 2.75; 95% CI: 1.19-6.91; p = 0.024) showed significant associations with a poor prognosis of cerebral infarction of unknown origin at admission.

Conclusions

Thick AAPs could be a factor in the prediction of a poor prognosis of cerebral infarction of unknown origin at admission. The establishment of international standards for aortogenic brain embolisms is required. Future prospective studies should examine cerebral infarctions of unknown origin.

Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification

INTRODUCTION

To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group.

METHODS

We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries.

RESULTS

125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques ( p = 0.283) or intracranial arterial stenosis ( p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% ( p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% ( p = 0.00).

DISCUSSION

Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention.

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Ischemic lesion burden and characteristics of aortic atheroma

BACKGROUND

To investigate whether ischemic lesion burden including lesion pattern, number, and volume would vary depending on risk stratification of aortic atheroma (AA).

METHODS

Acute stroke patients were enrolled if they had (1) acute ischemic lesions on diffusion-weighted imaging within 5 days of symptom onset, (2) cardioembolic stroke established through extensive workup, and (3) only ascending or arch AA detected by transesophageal echocardiography as an embolic source. AA was classified as complex (protruding ≥4 mm into the aortic lumen or any mobile or ulcerative component) or simple (<4 mm).

RESULTS

Eighty-one patients (male: 65.4% and age: 66.7 ± 11.0 years) were included in the study. Thirty-four patients (41.9%) had complex atheroma. These patients had a greater number of ischemic lesions (median: 2 lesions [range: 1-42] versus one lesion [range: 1-27], P = .017) and a larger infarct size (9.01 cc [range: 3.58-49.14] versus 4.6 cc [range: 2.3-13.28), P = .056) than the simple atheroma group. Multivariable logistic regression analysis showed that ischemic lesion volume was independently associated with complex atheroma (odds ratio: 1.03, 95% confidence interval: 1.002-2.148, P = .035), while multiple lesions were related (odds ratio: 3.03, 95% confidence interval: .88-10.42, P = .079).

CONCLUSIONS

Ischemic lesion burden in patients with AA differed according to AA characteristics, suggesting that the morphological features of AA could reflect an embolic potential of AA.

Simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) imaging for carotid atherosclerotic disease evaluation

A simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) MR imaging technique is proposed to detect both luminal stenosis and hemorrhage in atherosclerosis patients in a single scan. Thirteen patients with diagnosed carotid atherosclerotic plaque were admitted after informed consent. All scans were performed on a 3T MR imaging system with SNAP, 2D time-of-flight and magnetization-prepared 3D rapid acquisition gradient echo sequences. The SNAP sequence utilized a phase sensitive acquisition, and was designed to provide positive signals corresponding to intraplaque hemorrhage and negative signals corresponding to lumen. SNAP images were compared to time-of-flight images to evaluate lumen size measurements using linear mixed models and the intraclass correlation coefficient. Intraplaque hemorrhage identification accuracy was evaluated by comparing to magnetization-prepared 3D rapid acquisition gradient echo images using Cohen's Kappa. Diagnostic quality SNAP images were generated from all subjects. Quantitatively, the lumen size measurements by SNAP were strongly correlated (intraclass correlation coefficient = 0.96, P < 0.001) with those measured by time-of-flight. For intraplaque hemorrhage detection, strong agreement (κ = 0.82, P < 0.001) was also identified between SNAP and magnetization-prepared 3D rapid acquisition gradient echo images. In conclusion, a SNAP imaging technique was proposed and shows great promise for imaging both lumen size and carotid intraplaque hemorrhage with a single scan.

Interactions between cardiovascular and cerebrovascular disease

OPININION STATEMENT: All patients with ischemic stroke should undergo a comprehensive assessment of cardiovascular risk. Patients with carotid artery disease, symptoms of cerebral ischemia and high cardiovascular risk profiles should be considered for noninvasive testing for coronary artery disease (CAD). Routine testing for CAD before carotid endarterctomy is not recommended. Patients with coexisting coronary and carotid artery disease should be more aggressively treated for reducing their "very high" risk of cardiovascular events. In patients candidates to carotid revascularization, a preoperative coronary angiography and coronary revascularization are not recommended. Warfarin is recommended in all patients with moderate to high risk of stroke. Novel oral anticoagulants represent an attractive alternative to warfarin. However, their place in therapy in clinical practice is not yet established. Percutaneous closure of the left atrial appendage for stroke prophylaxis may be considered in selected patients with atrial fibrillation and contraindications for oral anticoagulant therapy. Warfarin is not indicated in patients with heart failure who are in sinus rhythm. Percutaneous closure of patent foramen does not seem to be superior to medical therapy for the prevention of recurrences in patients with cryptogenic stroke.

Secondary stroke prevention: patent foramen ovale, aortic plaque, and carotid stenosis

Stroke is the most debilitating cardiovascular event. It has a variety of causes that may be present simultaneously. In young or otherwise healthy people, the search for a patent foramen ovale (PFO) has become standard. In stroke of the elderly, atherosclerosis and atrial fibrillation are in the foreground but the PFO should not be ignored. The risk of a PFO-related stroke over time is controversial and so is its prevention by device closure. The association of proximal aortic plaques in arteries subtending the brain and stroke is considered strong, ignoring that it is as putative as that of the PFO. Statins can prevent progression of such plaques. Antiplatelet agents in asymptomatic and surgical endarterectomy in symptomatic patients or highly ulcerated lesions are the treatment of choice. Stenting with protection devices was shown competitive in selected patients.

CT angiography of the aorta is superior to transesophageal echocardiography for determining stroke subtypes in patients with cryptogenic ischemic stroke

BACKGROUND

The etiology of ischemic strokes remains cryptogenic in about one third of patients, even after extensive workup in specialized centers. Atherosclerotic plaques in the aorta can cause thromboembolic events but are often overlooked. They can elude standard identification by transesophageal echocardiography (TEE), which is invasive or at best uncomfortable for many patients. CT angiography (CTA) can be used as an alternative or in addition to TEE if this technique fails to visualize every part of the aorta and in particular the aortic arch.

METHODS

We prospectively studied 64 patients (47 men, age 60 ± 13 years) classified as having cryptogenic stroke after standard and full workup [including brain MRI and 24-hour electrocardiogram (ECG)] with ECG-triggered CTA of the aorta in search of plaques and compared the results with those of TEE. Investigators were blinded to the results of both techniques. Plaques were graded on CTA according to their presence (0 = not present; 1 = mild; 2 = severe) and degree of calcification (1a or 2a = noncalcified; 1b or 2b = calcified). Associations with risk factors and infarct localization were also assessed.

RESULTS

Only 21 of 64 patients (32.8%) had aortic plaques identified by TEE, compared to 43 of 64 (67.2%) with CTA (p < 0.05). The plaque localization was as follows (TEE vs. CTA): ascending aorta, 10 vs. 20 (p < 0.05); aortic arch, 10 vs. 40 (p < 0.05), and descending aorta, 20 vs. 34 (p < 0.05). Grade 1 plaques were most commonly found in the aortic arch (25; 39%), while grade 2 plaques were most often detected in the aortic arch (15; 23.4%) and the descending aorta (14; 21.9%). There was no significant correlation between plaque location, infarct territory or vascular risk profile, except for hypertension (p = 0.003), which was significantly associated with the presence of plaques.

CONCLUSIONS

CTA identifies more plaques throughout the aortic arch and around the origins of the major cerebral arteries in particular compared to TEE. These may represent potential embolic sources of acute ischemic stroke. Better plaque detection may have an impact on the best available secondary prevention regimen in individual patients if proximal embolic sources are suspected.

Comparison of frequencies of patent foramen ovale and thoracic aortic atherosclerosis in patients with cryptogenic ischemic stroke undergoing transesophageal echocardiography

Studies have shown an association between the presence of a patent foramen ovale (PFO) and cryptogenic stroke (CS) in patients aged <55 years. In addition, protruding atheromatous plaques in the ascending aorta and aortic arch are an independent risk factor for ischemic stroke in patients aged ≥55 years. The aim of this study was to determine the association of CS in the 2 age groups with PFO and with atheromatous plaques in the ascending aorta and in the aortic arch. Transesophageal echocardiograms in 229 patients evaluated for CS were compared to those in 314 patients evaluated for cardiac disease other than PFO with no histories of stroke (the control group). The prevalence of PFO and the presence of complex atheromatous plaques in the ascending aorta and aortic arch were determined in all patients and compared between the CS and control patients in the 2 age groups. The prevalence of PFO was significantly higher in patients with CS than in control patients among those aged <55 years (31 of 114 [27%] vs 24 of 171 [14%], p = 0.006) and those aged ≥55 years (28 of 115 [24%] vs 21 of 143 [15%], p = 0.049). The incidence of atrial septal aneurysm was similar in the 2 groups irrespective of patient age, as was the prevalence of complex atheromatous plaques. Multivariate analysis showed that PFO was independently associated with CS, irrespective of patient age (<55 years: odds ratio 2.4, 95% confidence interval 1.3 to 4.5, p = 0.01; ≥55 years: odds ratio 1.9, 95% confidence interval 1.1 to 3.5, p = 0.03). In conclusion, PFO was significantly associated with CS in younger (aged <55 years) and older (aged ≥55 years) patients. Atrial septal aneurysm and complex atheromas in the ascending aorta and aortic arch do not appear to be associated with CS.

Differences in diffusion-weighted image and transesophageal echocardiographical findings in cardiogenic, paradoxical and aortogenic brain embolism

BACKGROUND AND PURPOSE

The purpose of the present study was to clarify the difference in the infarct topography on diffusion-weighted image (DWI) and cardiac and aortic findings on transesophageal echocardiography (TEE) in stroke patients with different embolic sources.

METHODS

We studied 270 consecutive patients with acute ischemic stroke who had DWI-documented cortical or subcortical infarcts without significant stenosis of the cerebral arteries. As embolic sources, cardiac diseases, right-to-left shunt diseases and an aortic arch atheroma ≥4.0 mm in thickness were identified using various diagnostic tools including TEE.

RESULTS

Seventy-eight (29%) patients had multiple embolic sources. Large infarcts were common in patients in whom cardiac disease was the only embolic source and uncommon in patients in whom aortic atheroma was the only embolic source (p < 0.0001). Vertebrobasilar infarcts were relatively common in patients only having aortic atheromas. Atrial septal aneurysms were more common in patients with a right-to-left shunt than in those with a shunt plus other embolic sources (p = 0.0036). Unique characteristics of the arch atheroma (mobile plaque, extension to branches, or ulcer formation; p < 0.0001) as well as small or moderate-sized infarcts (p = 0.0004) were more common in patients with arch atheromas as the only embolic source than in those with atheromas plus other embolic sources.

CONCLUSIONS

Embolic stroke patients often have multiple embolic sources. The present study suggests the possibility that embolic stroke has unique clinical features depending on its source. DWI and TEE findings might be helpful in characterizing cardiogenic, paradoxical and aortogenic brain embolism.

Aortic atheroma and adverse cerebral outcome: risk, diagnosis, and management options

Aortic atheromatous disease is a common finding in the patient presenting for cardiac surgery. Adverse neurologic outcome has been closely linked to the extent of aortic atherosclerosis. In order to optimize perioperative outcomes, the location and severity of disease needs accurate characterization using multimodal techniques. Although various preoperative radiographic techniques have variably identified patients with significant atheroma, intraoperative echocardiographic imaging has proven most useful in localizing and characterizing the degree of aortic atheroma. Epiaortic assessment of the ascending aorta has been utilized in guiding surgical modifications and interventions aimed at reducing the risk of neurologic injury. Although no particular technique has been definitely studied, avoidance of the identifiable atheromatous aortic region has been a main feature of the various modifications employed to optimize neurologic outcome after cardiac surgery.

Complex atheromatosis of the aortic arch in cerebral infarction

In many stroke patients it is not possible to establish the etiology of stroke. However, in the last two decades, the use of transesophageal echocardiography in patients with stroke of uncertain etiology reveals atherosclerotic plaques in the aortic arch, which often protrude into the lumen and have mobile components in a high percentage of cases. Several autopsy series and retrospective studies of cases and controls have shown an association between aortic arch atheroma and arterial embolism, which was later confirmed by prospectively designed studies. The association with ischemic stroke was particularly strong when atheromas were located proximal to the ostium of the left subclavian artery, when the plaque was ≥ 4 mm thick and particularly when mobile components are present. In these cases, aspirin might not prevent adequately new arterial ischemic events especially stroke. Here we review the evidence of aortic arch atheroma as an independent risk factor for stroke and arterial embolism, including clinical and pathological data on atherosclerosis of the thoracic aorta as an embolic source. In addition, the impact of complex plaques (≥ 4 mm thick, or with mobile components) on increasing the risk of stroke is also reviewed. In non-randomized retrospective studies anticoagulation was superior to antiplatelet therapy in patients with stroke and aortic arch plaques with mobile components. In a retrospective case-control study, statins significantly reduced the relative risk of new vascular events. However, given the limited data available and its retrospective nature, randomized prospective studies are needed to establish the optimal secondary prevention therapeutic regimens in these high risk patients.

Late onset of cholesterol crystal embolism after thrombolysis for cerebral infarction

A 73-year-old man was admitted to our hospital because of bilateral foot pain. He was treated with thrombolysis for cerebral infarction about 5 months ago. Anticoagulants had not been used because of hemorrhagic infarction. The pulses of bilateral pedal arteries were palpable, but cyanosis was present in the bilateral toes. Laboratory data indicated azotemia and eosinophilia. Magnetic resonance imaging revealed multiple plaques of the thoracic and abdominal aorta, one of which was ulcerated. Skin biopsy proved the diagnosis of cholesterol crystal embolism (CCE). Because no invasive vascular procedure was performed, we assumed that CCE in this patient was related to thrombolysis. We should be cautious for late onset of CCE after thrombolysis.

Aortic arch plaques and risk of recurrent stroke and death

BACKGROUND

Aortic arch plaques are a risk factor for ischemic stroke. Although the stroke mechanism is conceivably thromboembolic, no randomized studies have evaluated the efficacy of antithrombotic therapies in preventing recurrent events.

METHODS AND RESULTS

The relationship between arch plaques and recurrent events was studied in 516 patients with ischemic stroke who were double-blindly randomized to treatment with warfarin or aspirin as part of the Patent Foramen Ovale in Cryptogenic Stroke Study (PICSS), based on the Warfarin-Aspirin Recurrent Stroke Study (WARSS). Plaque thickness and morphology were evaluated by transesophageal echocardiography. End points were recurrent ischemic stroke or death over a 2-year follow-up. Large plaques (> or =4 mm) were present in 19.6% of patients; large complex plaques (those with ulcerations or mobile components) were seen in 8.5%. During follow-up, large plaques were associated with a significantly increased risk of events (adjusted hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.04 to 4.32), especially those with complex morphology (HR, 2.55; 95 CI, 1.10 to 5.89). The risk was highest among cryptogenic stroke patients, both for large plaques (HR, 6.42; 95% CI, 1.62 to 25.46) and large complex plaques (HR, 9.50; 95% CI, 1.92 to 47.10). Event rates were similar in the warfarin and aspirin groups in the overall study population (16.4% versus 15.8%; P=0.43).

CONCLUSIONS

In patients with stroke, especially cryptogenic stroke, large aortic plaques remain associated with an increased risk of recurrent stroke and death at 2 years despite treatment with warfarin or aspirin. Complex plaque morphology confers a slight additional increase in risk.

Atherosclerotic Burden Findings in Young Cryptogenic Stroke Patients With and Without a Patent Foramen Ovale

Background and Purpose— To further determine the mechanisms of cryptogenic stroke or transient ischemic attack in young patients, we evaluated indices of atherosclerosis in patients ≤55 years old diagnosed with cryptogenic cerebrovascular event comparing those with patent foramen ovale (PFO) with those without PFO.

Methods— This was a prospective study including 100 consecutive patients ≤55 years old (mean age, 45±8 years; 56 males) diagnosed with cryptogenic stroke/transient ischemic attack. PFO was identified in 59 of these patients with the use of transesophageal echocardiography with contrast study. The following surrogate markers of atherosclerosis were evaluated in all patients: carotid intima media thickness as measured by carotid ultrasonography and endothelial function as determined by brachial flow-mediated vasodilation. The same measurements were obtained in a control group of 50 age- and sex-matched control subjects.

Results— Patients without PFO were more likely to be current smokers and obese and more frequently had a history of hypertension and dyslipidemia. Carotid intima media thickness measurements were higher ( P <0.0001) in patients without PFO (1.03±0.31 mm) compared with those with PFO (0.75±0.20 mm) and control subjects (0.79±0.17 mm). The absence of PFO was also associated with lower brachial flow-mediated vasodilation (without PFO: 5.04±3.39%; with PFO: 7.16±4.09%; control subjects: 7.33±4.07%; P =0.02). There were no differences in carotid intima media thickness and flow-mediated vasodilation between patients with stroke/transient ischemic attack with PFO and control subjects. The presence of PFO was independently associated with reduced carotid intima media thickness ( P <0.0001) and increased flow-mediated vasodilation ( P =0.019).

Conclusions— In patients ≤55 years old diagnosed with cryptogenic stroke/transient ischemic attack, the presence of PFO was associated with a lower atherosclerotic burden as measured by carotid intima media thickness and endothelial function with no differences compared with a control group without cerebrovascular event. These results suggest that an atherosclerotic-mediated mechanism may be involved in cryptogenic stroke/transient ischemic attack in patients without PFO, whereas a nonatherosclerotic mechanism may mediate the cerebrovascular event in the presence of PFO.

Aortic arch atheroma

Severe atheroma of the aortic arch has now been established as an important risk factor and mechanism for stroke and peripheral embolism. The odds ratio for stroke or peripheral embolism in patients with severe arch atheroma is greater than four, and for mobile atheroma it is greater than 12. The prevalence of severe arch atheroma among patients presenting with acute ischaemic stroke, at over 20%, is in the same order as that of atrial fibrillation and carotid atherosclerosis. In patients with ischaemic stroke for which no cause has been identified, it is reasonable to determine as to whether they have severe arch atheroma by performing a transoesophageal echocardiogram. Recurrent stroke is common in patients with aortic arch atheroma that are thicker than 4 mm or with mobile components, particularly in the elderly, cigarette smokers, and those with hypertension or diabetes. Patients found to have severe atheroma are at high risk of recurrent events (14.2% per year) and may, therefore, need an aggressive secondary prevention strategy. Currently, there is uncertainty as to what this should be, but either combination antiplatelet therapy (aspirin plus clopidogrel) or anticoagulation with warfarin (target INR 2.0-3.0) are commonly used. Which of these is most effective will be evident after the completion of the aortic arch related cerebral hazard trial.

Aortic atherosclerosis, hypercoagulability, and stroke the APRIS (Aortic Plaque and Risk of Ischemic Stroke) study

OBJECTIVES

Our goal was to assess the effect of hypercoagulability on the risk of stroke in patients with aortic plaques.

BACKGROUND

Atherosclerotic plaques in the aortic arch are a risk factor for ischemic stroke. Their relationship with blood hypercoagulability, which might enhance their embolic potential and affect treatment and prevention, is not known.

METHODS

We performed transesophageal echocardiography in 255 patients with first acute ischemic stroke and in 209 control subjects matched by age, gender, and race/ethnicity. The association between arch plaques and hypercoagulability, and its effect on the stroke risk, was assessed with a case-control design. Stroke patients were then followed prospectively to assess recurrent stroke and death.

RESULTS

Large (> or =4 mm) arch plaques were associated with increased stroke risk (adjusted odds ratio [OR]: 2.4, 95% confidence interval [CI]: 1.3 to 4.6), especially when ulcerations or superimposed thrombus were present (adjusted OR: 3.3, 95% CI: 1.4 to 8.2). Prothrombin fragment F 1.2, an indicator of thrombin generation, was associated with large plaques in stroke patients (p = 0.02), but not in control subjects. Over a mean follow-up of 55.1 +/- 37.2 months, stroke patients with large plaques and F 1.2 over the median value had a significantly higher risk of recurrent stroke and death than those with large plaques but lower F 1.2 levels (230 events per 1,000 person-years vs. 85 events per 1,000 person-years; p = 0.05).

CONCLUSIONS

In patients presenting with acute ischemic stroke, large aortic plaques are associated with blood hypercoagulability, suggesting a role for coagulation activation in the stroke mechanism. Coexistence of large aortic plaques and blood hypercoagulability is associated with an increased risk of recurrent stroke and death.

Mitral annular calcification as a marker of complex aortic atheroma in patients with stroke of uncertain etiology

The aim of this study was to evaluate the presence of dense mitral annular calcification as a marker of complex aortic atherosclerosis in patients with stroke of uncertain etiology. One hundred twenty-one patients with stroke of uncertain etiology were evaluated for complex aortic atherosclerotic plaques; their presence and severity were correlated with transthoracic echocardiographic findings, demographic data, and cardiovascular risk factors. Complex plaques in the ascending aorta or aortic arch were found in 72 of the 121 patients (59.5%). The only difference seen in patients with or without plaques was the presence of dense mitral annular calcification (58.3 vs 16.3%; P < 0.001). Dense mitral annular calcification (n = 50) was associated with higher prevalence of complex aortic plaques (84.0% vs 42.3%; P < 0.001), mobile components (28.0% vs 9.9%; P < 0.01), and protruding (80.0% vs 36.6%; P < 0.001), ulcerated (16.0% vs 1.4%; P < 0.01), and multisite complex plaques (46.0% vs 9.0%; P < 0.001). Therefore, in patients with stroke of uncertain etiology dense mitral annular calcification is an important marker of aortic atherosclerosis with high risk of embolism, and this association may explain in part the high prevalence of stroke and peripheral embolism in patients with mitral annular calcification.