Moderate Atheroma of the Aortic Arch and the Risk of Stroke

BACKGROUND AND PURPOSE: Severe atheroma >or=4 or 5 mm of the aortic arch is a risk factor for stroke. We investigated the most predictive characteristics of arch atheroma, including maximal plaque thickness, for subsequent cardiovascular events, and also examined whether moderate atheroma<4 mm is a risk of cerebral emboli. METHODS: The maximal plaque thickness (MPT) and plaque morphologies of the aortic arch were evaluated by transesophageal echocardiography in 236 patients with ischemic stroke. We assessed the relationship between the incidence of cardiovascular events, recurrent stroke or myocardial infarction, and the characteristics of the atheroma. We also investigated the thickness of atheroma in patients with known causes of stroke (n=148) and in patients with undetermined causes (n=19). RESULTS: Cardiovascular events occurred in 47 patients in the follow-up period with a mean of 3.5 years. MPT was a significant risk factor of the cardiovascular events, although plaque morphologies were not. For the receiver operator characteristics curve analysis, the suitable cutoff point of MPT associated with the cardiovascular events was 3.5 mm. Patients with MPT >or=3.5 mm had a higher risk of cardiovascular events than did those with MPT<3.5 mm. In addition, aortic atheroma with MPT >or=3.5 mm was more frequently observed in patients with undetermined causes of stroke than those with known causes at 68 vs. 39% (p=0.024). CONCLUSIONS: MPT >or=3.5 mm is the best predictor of subsequent cardiovascular events and a possible cause of embolic stroke.