Aortic atherosclerosis and stroke.

Methods: Studies using transesophageal echocardiography (TEE) suggest aortic atherosclerosis may be a risk factor for stroke, particularly stroke of undetermined mechanism, but controls in prior studies were not balanced for vascular risk factors. We used TEE to evaluate aortic atherosclerosis in 60 patients with stroke compared with a high-risk control population of 46 subjects. We also examined the possible association of plasma viscosity and fibrinogen levels to aortic atherosclerosis.

Results: The mean maximal plaque thickness (MMPT) was similar for the control (2.8 +/- 3.6 mm) and the stroke group (3.3 +/- 3.5 mm), but varied with stroke mechanism. The MMPT was similar in stroke of undetermined and atherosclerotic mechanism [3.5 +/- 4 mm (n = 25) and 4.2 +/- 4.3 mm (n = 16), respectively], significantly greater than in stroke of other mechanisms (1.7 +/- 1.2 mm, P < .05, n = 19). Patients with stroke of undetermined mechanism were four times more likely (95% confidence interval [CI] 1.2-12) to have plaques >/=5 mm compared with controls. Ulcerated plaque was associated with plaque thickness (P < .001) and plasma viscosity (P < .001).

Conclusions: Aortic atherosclerosis is associated with stroke of undetermined cause suggesting atherosclerosis is a cause of stroke of undetermined etiology. Plaque ulceration was associated with the thickness of aortic plaque and plasma viscosity.