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.     

Aortic source of brain embolism

Opinion statement Aortic arch atheroma has more recently been identified as an independent risk factor for ischemic stroke. Initially, this was a result of careful autopsy observations, then followed by a series of in vivo studies in which aortic arch atheroma was identified by transesophageal echocardiography. The association of aortic arch atheroma with ischemic stroke is most likely causal, given that the stroke risk increases with increasing thickness of arch atheroma. There is quite a sharp increase in stroke risk for atheroma of 4 mm or greater compared with lesser thicknesses. The clinical diagnosis is suggested when transient ischemic attack or ischemic stroke has occurred in which no obvious cardiac or arterial source of embolism is found. The presence of aortic arch atheroma is usually detected by transesophageal echocardiography and sometimes by magnetic resonance imaging or computed tomography. There is uncertainty about clinical management, particularly for secondary prevention. Options include the use of antiplatelet agents, anticoagulants, thrombolysis, or surgery. The latter two options have only been described rarely in case reports. Of the less invasive approaches, combination antiplatelet therapy with aspirin and clopidogrel is favored, or the use of warfarin. The Aortic arch Related Cerebral Hazard (ARCH) trial is being conducted to determine which of these is more effective in minimizing a composite outcome cluster of ischemic stroke, intracranial hemorrhage, myocardial infarction, peripheral embolism, or vascular death. Other more general management strategies should include reasonably aggressive risk factor control with blood pressure and lipid-lowering therapies and, if indicated, careful diabetic control.     

亚急性期脑梗死患者全脑血管造影致脑栓塞的危险因素分析

目的探讨亚急性期脑梗死患者数字减影全脑血管造影(DSA)致脑栓塞的可能危险因素。方法 327例亚急性期脑梗死患者行全脑DSA,手术前后24h内行头颅MRI+弥散加权成像(DWI)检查,收集其临床和实验室资料。根据头颅MRI+DWI结果分为栓塞组65例和非栓塞组262例。比较2组差异筛选可能的危险因素,进一步行logistic回归分析致脑栓塞的独立危险因素。结果头颅MRI+DWI提示脑栓塞65例,其中有症状19例,无症状46例;logistic回归分析显示,年龄≥65岁、空腹血糖≥11.1mmol/L、纤维蛋白原≥5.0g/L、颈动脉斑块、Ⅲ型主动脉弓、手术操作时间≥30min是脑栓塞的独立危险因素(P<0.05)。结论高龄、高纤维蛋白原水平、颈动脉斑块和Ⅲ型主动脉弓、血糖控制不佳及手术时间操作过长的亚急性脑梗死患者行全脑DSA易发生脑栓塞,临床上对该类高危患者必须加以重视,慎重筛选造影患者。     

Transthoracic echocardiographic diagnosis of mobile aortic arch atherothrombosis associated with stroke

Aortic arch atherosclerosis is associated with an increased risk of stroke or TIA. Up to now, transesophageal echocardiography has been the standard method for diagnosing protruding and/or mobile aortic arch atherosclerosis. We report a case where a mobile aortic arch atheroma was diagnosed using transthoracic echo in a patient with a recent stroke.     

Protruding aortic atheromas predict stroke in elderly patients undergoing cardiopulmonary bypass: experience with intraoperative transesophageal echocardiography.

Protruding atheromas of the aortic arch identified by transesophageal echocardiography have been implicated as a cause of stroke in elderly patients. One hundred thirty patients greater than or equal to 65 years of age were studied with intraoperative transesophageal echocardiography to detect aortic arch protruding atheromas and determine if these patients were at higher risk for perioperative stroke. Protruding atheromas were identified in 23 (18%) of 130 patients. In 19 (83%) of these 23 patients, palpation of the aortic arch at operation did not identify significant abnormalities. Five patients (4%) had perioperative stroke. Logistic regression identified aortic arch atheroma as the only historical or procedural variable that was predictive of stroke (odds ratio 5.8, 95% confidence interval 1.2 to 27.9, p less than 0.03). A history of peripheral or cerebrovascular disease, presence of aortic calcification, cardiac risk factors, age and duration of cardiopulmonary bypass did not predict stroke. In contrast, patients with protruding atheromas with mobile components were at highest risk. There were 3 (25%) of 12 patients with a mobile atheroma who had a stroke versus 2 (2%) of 118 patients without a mobile atheroma (chi-square = 10.3, p = 0.001). Displacement and detachment of the frail, protruding atherosclerotic material by aortic arch cannulation or by the high pressure jet emanating from the cannula tip may play an important role in the creation of embolization and stroke.     

Aortic atheroma. An unknown source of ischemic stroke

Cerebrovascular mortality represents 25% of all cardiovascular mortality. Defining the pathological mechanism of an episode of ischemic stroke is important for epidemiological, prognostic and overall therapeutic purposes. About 1/4 of ischemic strokes are defined as being of unknown cause. The use of transesophageal echocardiography for studying the aortic arch and thoracic aorta, revealed that aortic atheroma can be considered as an embolic source. Retrospective studies documented a significant prevalence of atheroma >4 mm in the aortic arch in patients with previous stroke (15%); while prospective studies documented an increased risk for cardiovascular events in patients with plaque of =/> 4 mm in thickness at the level of the thoracic aorta compared with controls without these lesions: in particular, the incidence of recurrent stroke is 12%/year, while the incidence of cardiovascular events is 26%. Plaques defined unstable and at risk of embolic event are protrudent, >4 mm in thickness, without calcification and have on their surface mobile thrombus. Embolization from a protrudent atheroma can have a iatrogenic cause, that is cardiac catheterization or placement of an intra-aortic balloon- pump or during cardiopulmonary bypass. The management of the subject with aortic atheroma is not well defined. Encouraging dates with the use of statins are from a recent meta-analysis also anticoagulant treatment versus antiplatelet treatment, reduced incidence of stroke in a significant manner. The surgical therapy of aortic endoarterectomy, has, at this moment, a limited indication, because is not without risk. Transesophageal ecocardiography is a method of choice for the study of the aortic atheroma and it should be done in every patient with stroke by unknown cause.     

主动脉弓粥样硬化斑块与卒中

主动脉弓粥样硬化斑块是栓塞性卒中的原因之一.随着对主动脉弓斑块研究的深入.其与卒中的关系也越来越清楚,尤其是主动脉弓斑块厚度≥4 mm与原因不明性卒中、卒中复发以及其他血管事件有关.虽然对主动脉弓斑块与卒中的临床特点有了进一步的了解,但仍然存在许多疑问.     

Atheromatous disease of the thoracic aorta and systemic embolism. Clinical picture and therapeutic challenge

Systemic embolism is a frequent cause of stroke. At the beginning of the last decade by introduction of transesophageal echocardiography and other imaging techniques atheromatosis of the aortic arch has been recognized as an important source of embolism. Formerly in the pre-TEE era, this entity was included into cryptogenic strokes. Aortic atheromas are found in about one quarter of patients presenting with embolic events. The severity of atherosclerosis graded by TEE correlates with the risk for future embolism, especially if mobile lesions or superimposed thrombi are present. Independent of plaque extension, patients with unstable plaques characterized by echo-lucency, inhomogenity, lacking of calcifications, ulceration, mobile parts and concomitant spontaneous echo contrast within the aorta have a higher risk for embolic events. However, the diagnosis of aortic atheromatosis is mostly established if an embolic event has already occurred. Therefore, it is important to identify patients at risk, especially before they undergo interventions with manipulation at the aorta like coronary bypass surgery. Risk factors are age above 70, diabetes mellitus, hyperlipidemia, arterial hypertension, aortic calcifications on standard chest X-ray, elevated serum levels of C-reactive protein, other inflammatory markers, and an activated coagulation. Randomized studies for treatment of patients with severe aortic atheromatosis are not yet existing. Warfarin has been shown to prevent stroke in patients with mobile atheromas and superimposed thrombi, but there are case reports about aggravation of cholesterol embolism under warfarin treatment. It is concluded from other atherosclerotic manifestations that plaque stabilizing treatment with statins and ACE inhibitors is also beneficial.     

Role of complex aortic atheroma plaques in the recurrence of unexplained cerebral infarction

INTRODUCTION AND OBJECTIVES: In a subgroup of patients with cerebral infarction, noninvasive diagnostic explorations fail to disclose the etiology. We studied the clinical course and the usefulness of transesophageal echocardiography to diagnose complex aortic atheroma plaques in patients with cerebral infarction of uncertain cause with recurrence of ischemia. PATIENTS AND METHOD: In a study population of 1840 consecutive patients with a first cerebral infarction evaluated with a screening protocol for transesophageal echocardiography, the etiology remained uncertain in 248 cases. These patients were followed during 1 year of treatment with antiplatelet agents, and transesophageal echocardiography was done if cerebral ischemia recurred. We compared the prevalence of complex aortic atheroma plaques in patients with recurrence and in patients with cerebral infarction of unknown etiology in the French Study of Aortic Plaques in Stroke, in whom there was no recurrence of cerebral infarction. RESULTS: Recurrent cerebral infarction was documented in 17 of our 248 patients with infarction of unknown etiology (6.9%). Transesophageal echocardiography established the etiology in 15 of these patients (88.2%) with complex aortic atheroma plaques being identified in 14 cases (82.4%). In contrast, in patients with cerebral infarction of unknown etiology in the French study without recurrent cerebral infarction during the first year of follow-up, the prevalence of complex plaques was 21.1% (P<.0001). CONCLUSIONS: During the first year of treatment with antiplatelet agents, most patients with cerebral infarction of unknown etiology had no recurrences. In the small subgroup with short-term recurrence, transesophageal echocardiography yielded the etiologic diagnosis in 88.2% of cases: the pathology most frequently involved was complex atherosclerotic disease of the aortic arch.     

Protruding atheromas in the thoracic aorta: a newly recognized source of cerebral and systemic embolization

Up to 40% of stroke patients do not have an obvious etiology for their illness. Because transthoracic echocardiography is often negative in these patients, there has been increasing enthusiasm for transesophageal echocardiography (TEE) as a newer tool for evaluating patients with embolic disease. In a study of patients referred because of unexplained stroke or transient ischemic attacks, the most common finding was protruding atheroma in the aortic arch. In a case control study, protruding aortic atheromas were found in 33 of the 122 patients with emboli (27%). Mobile components to the atheromas were found in 11 case patients, and there were no mobile components found in any control patients. It is also possible that protruding aortic atheromas may play a role in patients with other sources of emboli (e.g., carotid disease). Atheromas may also cause emboli during catheterization, balloon pump placement, and cardiopulmonary bypass. The pathological composition of the lesions seen on TEE has been atheroma with superimposed thrombus. The correct treatment for patients with embolization due to protruding aortic atheromas has not yet been determined, although anticoagulation may play a role, since the mobile components to these lesions appear to be thrombus. We have recommended surgery for several patients. However, the operation is a major one with major potential complications, including aortic dissection. TEE should be done in patients with unexplained emboli, and it may also play a role in patients with other sources of embolization. TEE should be considered in elderly patients or those with extensive vascular disease before cardiac catheterization or heart surgery. In addition, cannulation techniques during bypass can be modified to avoid atheromas. The ideal medical and/or surgical approaches to patients with protruding atheromas remain to be clarified.     

The improved yield of transesophageal echocardiography over transthoracic echocardiography in patients with neurological events is largely due to the detection of aortic protruding atheromas

It is important to determine what, if any, the added contribution of transesophageal echocardiography is to the evaluation of patients with unexplained strokes and transient ischemic attacks. Transesophageal echocardiography was performed in 283 consecutive patients over an 8-month period. The reason for referral in 63 of these patients was unexplained stroke or transient ischemic attack. These 63 studies were evaluated for the presence of lesions that could be etiologic in these patients, including protruding aortic atheromas, spontaneous echo contrast, atrial septal aneurysms, and atrial clots. The transesophageal and transthoracic techniques were compared. The main finding was that there were 23 abnormal findings that might have been responsible for stroke or transient ischemic attacks seen on transesophageal echocardiography, which were not visualized on transthoracic echocardiography. Transthoracic echocardiography was false negative in 19 (30%) of 63 patients. None of the protruding aortic arch atheromas seen on transesophageal echocardiography were diagnosed with transthoracic echocardiography. Transesophageal echocardiography is indicated in the evaluation of patients with unexplained strokes and transient ischemic attacks, and the added yield of this technique is largely due to the finding of protruding aortic arch atheromas.     

Echocardiographic risk stratification for ischemic stroke in non‐rheumatic atrial fibrillation: Importance of aortic plaques detected by transesophageal echocardiography*

Background: The aim of the present paper was to assess the prevalence of atherosclerotic aortic plaques in non‐rheumatic atrial fibrillation and their relation to ischemic stroke. Although aortic plaques are frequently seen in the elderly, their significance remains unclear in relation to ischemic stroke in patients with atrial fibrillation. Methods: Transesophageal echocardiography was performed on 56 patients (age 61 ± 10 years) with atrial fibrillation. The aorta was divided into two segments (i.e. the proximal aorta that includes the ascending aorta and the aortic arch proximal to the ostium of the left subclavian artery, and the distal aorta that is the descending aorta distal to the left subclavian artery). Thickened intima = 3 mm in thickness was defined as aortic plaques. Results: Ischemic stroke was found in 14 of the 56 patients. Aortic plaques were detected in 25 of the 56 patients. All of these 25 patients had aortic plaques in the proximal aorta, and 17 of them also had aortic plaques in the distal aorta. Ischemic stroke was found in 11 of the 25 patients (44%) with aortic plaques, and three of the 31 patients (10%) without aortic plaques (P < 0.01). Conversely, aortic plaques were detected in 11 of the 14 patients (79%) with ischemic stroke, and in 14 of the 42 patients (33%) without (P < 0.01). The patients with ischemic stroke had a larger left atrium (47 ± 5 vs 43 ± 6 mm; P < 0.05) than those without. Aortic plaques were a correlate only of previous ischemic stroke (P < 0.05) by multiple logistic regression analysis. Conclusions: Atherosclerotic aortic plaques detected by transesophageal echocardio‐graphy are a correlate of previous ischemic stroke in patients with non‐rheumatic atrial fibrillation.     

Cardioembolic stroke

Cardiac sources of emboli account for over one quarter of all ischemic strokes. Strokes due to cardioembolism are in general severe and prone to early and long-term recurrence. Nonvalvular atrial fibrillation remains the most common cause of cardioembolic stroke. Despite the proven efficacy of oral anticoagulation, it is prescribed for less than half of the patients with risk factors for embolism and no contraindications for anticoagulation. The embolic risk of patent foramen ovale is low except when combined with an atrial septal aneurysm. Aortic arch atheroma as an independent risk factor for ischemic stroke is the subject of ongoing debate. As the risk of embolism is heterogeneous for the various potential cardioembolic conditions, accurate definition of stroke mechanism is very important to guide the most effective therapy.     

Carotid and cerebral angiography performed by cardiologists: cerebrovascular complications.

The management of extracranial carotid artery disease is primarily concerned with the prevention of acute stroke. In order to understand the current risks of carotid angiography performed by interventional cardiologists, we undertook a retrospective study to determine the neurologic complications in patients who underwent selective cerebral angiography. All patients undergoing studies that were limited to diagnostic aortic arch angiography and selective four-vessel cerebral angiography in the cardiac catheterization laboratories during the past 6 years were included in this study. Hospital records were reviewed to determine any in-hospital cerebrovascular complications following carotid angiography, ranging from transient ischemic attack to major disabling stroke or death. A total of 189 consecutive patients underwent 191 diagnostic studies limited to aortic arch and four-vessel cerebral angiography in the cardiac catheterization laboratories between 1 January 1995 and 31 December 2000. Only one (0.52%) neurological complication, a minor stroke, occurred in our study population. There were no transient ischemic attacks, major strokes, or death. We have shown that experienced interventional cardiologists can perform diagnostic aortic arch and selective carotid and vertebral angiography in a cardiac catheterization laboratory with a very low complication rate. Because the risks of angiography add to those of revascularization of the carotid artery, the most highly skilled angiographer, regardless of primary specialty, should perform these studies.     

Retrograde embolism from the descending thoracic aorta causing stroke: An underappreciated clinical condition

The mechanism of retrograde aortic blood flow is a complex and underreported clinical phenomenon. Complex plaques of the aortic arch are considered high-risk sources of cerebral emboli.¹ Aortic plaques situated in the descending thoracic aorta are however often overlooked and in fact can be more frequent potential sources of cerebral embolism through the mechanism of retrograde aortic blood flow. We present the case of an elderly Caucasian female who experienced recurrent posterior circulation embolic strokes where the only possible underlying etiology was found to be an atheroma in the descending thoracic aorta, possibly showering retrograde emboli.     

Systemic embolism in aortic arch atheromatosis

The role of aortic atheromatosis as a risk factor for systemicembolism and its relationship to other potential sources ofembolism was examined in 335 patients undergoing transoesophagealechocardiography for various clinical reasons. Multiple logisticregression analysis revealed a significant correlation betweenembolism and moderate (atheroma protruding less than 5 mm intothe aortic lumen, grade 2) to complex (atheroma protruding atleast 5 mm into the vessel humen with or without mobile components,grade 3) atherosclerosis of the aortic arch. Odds ratios were4.0 for grade 2 atheromatosis (95% CI 1.1–14.4; P<0.05)and 9.7 for grade 3 atheromatosis (95% CI 1.5–61.0; P<0.05).Other significant associations were found with cardiac thrombi(odds ratio 4.0, 95% CI 1.7–9.3; P<0.005) and hypertension(odds ratio 1.8, 95% CI 1.0-3.3; P<0.05). In a subset of163 patients in whom results of an ultrasound examination wereavailable, atherosclerosis of the carotid arteries was anothersignificant marker of embolism (odds ratio 2.0, 95% CI 1.2-3.3;V<0.01). In conclusion, aortic arch atheromatosis, which was predominantlyrecognized in patients with cerebrovascular events of undeterminedcause, seems to carry a risk of embolism that is comparableto cardiac and carotid atherosclerosis.     

Ischemic Stroke Patients with Non-Valvular Atrial Fibrillation have a Risk for Aortogenic Embolizations

We have a great interest in the article in Journal of Atherosclerosis and Thrombosis by Suzuki et al. titled Complex Aortic Arch Atherosclerosis in Acute Ischemic Stroke Patients with Non-Valvular Atrial Fibrillation. The authors demonstrated that 38.7% transesophageal echocardiography-derived complex aortic arch plaques (CAPs) among 106 patients with acute ischemic strokes with atrial fibrillation (AF), suggesting that patients with acute ischemic stroke and AF often had CAPs. The atheromatous lesions at the aortic arch are one of the causes of ischemic strokes. The cause of acute ischemic strokes in patients with AF could not only be cardiogenic embolisms due to AF but also aortogenic embolisms due to CAPs. The possibility of concomitant CAPs should be considered for stroke patients with AF. Non-obstructive general angioscopy has the possibility to detect aortic plaques in the aortic arch more accurately than TEE and might help to diagnose atheromatous plaques and embolic materials in the aortic arch. Further studies are needed to elucidate the causes of ischemic strokes and are expected to improve the outcomes for acute ischemic strokes in patients with AF.     

Aortic Tumor or Mobile Thrombus?

Isolated large mobile mass in the thoracic aorta can be due to thrombus or, rarely, aortic tumor. We report the case of a 61‐year‐old man with no history of medical problems presenting with neurologic deficits and in whom a large mobile echogenic mass in the distal aortic arch was found with transesophageal echocardiography. Given his few cardiovascular risk factors and absence of other systemic symptoms, he received anticoagulant therapy. Subsequent resolution of the aortic mass suggested a diagnosis of thrombus. This case illustrates an unusual manifestation of aortic arch atherosclerosis and underscores the utility of transesophogeal echocardiography for patients with ischemic stroke. (Echocardiography 2010;27:E21‐E22)     

Mobile atheromatous plaque of the aortic arch diagnosed by transthoracic echocardiography prior to coronary artery bypass surgery

A routine pre-operative chest X-ray of a patient admitted to our institution for an elective coronary artery bypass operation revealed a mildly dilated mediastinal silhouette, which led the cardiovascular surgery resident to schedule emergency transthoracic echocardiography (TTE), with a special note asking for detailed evaluation of the ascending aorta and aortic arch. TTE revealed a mobile atheroma at the aortic arch, which obliged the cardiac surgery team to modify their strategy to combined hemi-arcus aortae replacement and coronary artery bypass grafting (CABG). Although with transoesophageal echocardiography (TEE) a small portion of the ascending aorta may be obscured by the trachea, TEE provides higher resolution images than TTE. Therefore one can conclude that TEE is the imaging modality of choice for detecting aortic atheromatous plaques but in patients with low risk for stroke and aortic atheromas, a detailed TTE may be sufficient for the pre-operative assessment.     

Aortic arch atheroma and the risk of stroke

Brain infarction of unknown cause, known as cryptogenic stroke, represents 30% to 40% of all ischemic strokes, or approximately 400,000 cases each year in western Europe. In this category of patients new potential causes, such as aortic arch atheroma in the elderly, have been investigated in the past two decades.