Aortic Atheroma Morphology and the Risk of Ischemic Stroke in a Multiethnic Population

Marco R. Di Tullio, MD, Ralph L. Sacco, MD, Maria Teresa Savoia, MD, Robert R. Sciacca, EngScD, Shunichi Homma, MD, Departments of Medicine, Neurology, and Public Health (Epidemiology), Sergievsky Center, Columbia-Presbyterian Medical Center, New York, NY.

Am Heart J. 2000;139(2) 

In This Article

Abstract and Introduction

Background: Protruding atheromas in the aortic arch are an independent risk factor for ischemic stroke in the elderly. However, the role of atheroma morphologic characteristics (ulceration and mobility) has been less well characterized. Moreover, data have been obtained in predominantly white populations, and little is known about the association between atheromas and stroke in minorities.
Methods and Results: We performed transesophageal echocardiography in 152 elderly patients with stroke (58 white, 45 black, 49 Hispanic) and in 152 age- and race/ethnicity-matched control patients. Atheromas were classified as small (<4 mm in thickness), large noncomplex (>=4 mm, no ulceration or mobility), and complex (ulcerated or mobile). Logistic regression analysis was performed to assess the risk of stroke associated with different definitions of atheroma in the overall group and in the race-ethnic strata after adjusting for the presence of other stroke risk factors. Complex atheromas were strongly associated with stroke in the overall group (22.4% in cases, 2.6% in control patients; adjusted odds ratio [OR] 17.1, 95% confidence intervals [CI] 5.1 to 57.3), whereas large noncomplex atheromas conferred a mildly increased stroke risk (22.4% vs 16.5%; adjusted OR 2.4, 95% CI 1.1 to 5.1). Complex atheromas also were strongly associated with stroke in whites (adjusted OR 24.3, 95% CI 3.9 to 150.6) and Hispanics (adjusted OR 13.9, 95% CI 1.4 to 136). In blacks, complex atheromas were significantly more frequent in cases (15.6% vs 0%; P = .006), but their absence in control patients precluded the calculation of the OR. Complex atheromas were twice as frequent in white patients with stroke (32.3%) than in black or Hispanic patients (15.6% and 16.3%, respectively; P = .05).
Conclusions: Aortic atheroma complexity rather than size is strongly associated with ischemic stroke in the elderly. Complex atheromas are significantly associated with stroke in all 3 race-ethnic subgroups.

In recent years, the presence of protruding atheromas in the aortic arch has been recognized as a potential cause of cerebral or peripheral embolization in the elderly.[1,2,3,4,5,6,7,8] Several case-control studies with either autopsy findings[9] or transesophageal echocardiography[10,11,12] have identified large atheromas (ie, >4 mm in thickness) as one of the most powerful independent risk factors for ischemic stroke in patients >60 years of age. Prospective data also have been published on the high recurrence rate of cerebral or peripheral emboli in patients with protruding atheromas of the aortic arch identified by transesophageal echocardiography.[13,14,15] The risk of ischemic stroke mainly has been related to the thickness of the atheroma, with 4 mm[4,10,14,15] or 5 mm[11,12] most commonly used in the literature as a threshold of increased risk. The complexity of the atheroma (the presence of ulcerations on its luminal surface or of mobile components) has been considered as a potential cofactor in further enhancing stroke risk,[11,12] but its separate impact on stroke risk has begun to be recognized only recently.[15] Moreover, the data regarding aortic atheromas and stroke have been derived almost exclusively from white populations, and little is known about the frequency of aortic atheromas in other race-ethnic subgroups.[16] Therefore the impact of aortic arch atheromas on the risk of stroke in minorities remains largely unknown.

The current study is aimed at assessing the risk of stroke associated with complex atheromas as opposed to large but noncomplex lesions and the relative importance of aortic arch atheromas as a risk factor for ischemic stroke in elderly patients of various race-ethnicities after adjusting for the presence of other established stroke risk factors.