Aortic Source of Brain Embolism

Population-based study of the relationship between atherosclerotic aortic debris and cerebrovascular ischemic events

OBJECTIVE

To assess the validity of the suggestion that protruding atheromatous material in the thoracic aorta is an important cause of cerebrovascular ischemic events (CIEs) (ie, transient ischemic attack or ischemic stroke).

METHODS

This case-control study of Olmsted County, Minnesota, residents who underwent transesophageal echocardiography (TEE) from 1993 to 1997 included controls without CIE randomly selected from the population, controls without CIE referred for TEE because of cardiac disease, cases with incident CIE of obvious cause (noncryptogenic), and cases with incident CIE of uncertain cause (cryptogenic).

RESULTS

Of the 1135 subjects, 520 were randomly selected controls without CIE, 329 were controls without CIE referred for TEE, 159 were noncryptogenic CIE cases, and 127 were cryptogenic CIE cases. Complex atherosclerotic aortic debris in ascending and transverse segments of the arch was detected in 8 randomly selected controls (1.5%), 13 referred controls (4.0%), and 15 noncryptogenic (9.4%) and 4 cryptogenic (3.1%) CIE cases. After adjusting for age, sex, hypertension, smoking, atrial fibrillation, valvular heart disease, congestive heart failure, and atherosclerosis other than in the thoracic aorta, complex atherosclerotic aortic debris was not significantly associated with group status. With randomly selected controls as the referent group, odds ratios (95% confidence intervals) were 1.72 (0.61-4.87) for referred controls, 3.16 (1.18-8.51) for noncryptogenic CIE cases, and 1.39 (0.39-4.88) for cryptogenic CIE cases.

CONCLUSIONS

Complex atherosclerotic aortic debris is not a risk factor for cryptogenic ischemic stroke or transient ischemic attack but is a marker for generalized atherosclerosis and well-established atherosclerotic and cardioembolic mechanisms of cerebral ischemia. Embolization from the aorta is not a common mechanism of ischemic stroke or transient ischemic attack.

Heart diseases and stroke

A heterogeneous group of heart diseases, varying by cardiac anatomy and physiology, are responsible for a variety of embolic materials that result in cerebral and systemic embolism. Atrial fibrillation accounts for nearly half of all cardioembolic stroke, particularly in the elderly, but in the young congenital septal abnormalities such as patent foramen ovale play a more important role. Therapeutic strategies include stabilization or treatment of the underlying heart disease and prevention of embolism. Oral anticoagulant therapy is indicated for many but decision making on balancing the benefits versus risks can be difficult. New endovascular therapies and devices have become available and await clinical trials that allow them to be compared with existing medical therapies.

Embolic Cerebral Infarction Caused by Intraluminal Thrombus in the Carotid Siphon Successfully Treated With Combination of Anticoagulant and Antiplatelet Drugs

A 54-year-old-man experienced serial ischemic embolic strokes and retinal artery embolism in the left carotid territory. In the acute phase, intraluminal thrombus in the left carotid siphon and frequent microembolic signals (MES) in the left middle cerebral artery were detected with magnetic resonance angiography (MRA) and transcranial Doppler (TCD). The patient was initially treated with only heparin for 3 days; however, more than 30 MES per 30 min were still detected. After adding ticlopidine as an antiplatelet therapy, MES were suppressed completely. After starting combination therapy of heparin (later warfarin) and ticlopidine, repeated MRA confirmed resolution of carotid thrombus and ischemic stroke did not recur. For management of intraluminal thrombus in the carotid artery, MES with TCD was useful in evaluating the risk of distal embolism. Combination treatment with anticoagulants and ticlopidine can both resolve the thrombus and prevent distal embolism.