Atherosclerotic disease of the aortic arch as a risk factor for recurrent ischemic stroke.

BACKGROUND: Atherosclerotic disease of the aortic arch is found in 60 percent of patients 60 years of age or older who have had brain infarction. The aim of this study was to determine whether atherosclerotic plaques in the aortic arch are a risk factor for recurrent brain infarction and for vascular events in general (i.e., brain infarction, myocardial infarction, peripheral embolism, and death from vascular causes).

METHODS: For a period of two to four years, we followed a cohort of 331 patients 60 years of age or older who were consecutively admitted to the hospital with brain infarction (a total of 788 person-years of follow up). All patients underwent transesophageal echocardiography to determine whether atherosclerotic plaques were present in the aortic arch proximal to the ostium of the left subclavian artery. The patients were divided into three groups according to the thickness of the wall of the aortic arch ( < 1 mm, 1 to 3.9 mm, and > or = 4 mm).

RESULTS: The incidence of recurrent brain infarction was 11.9 per 100 person-years in patients with an aortic-wall thickness of > or = 4 mm, as compared with 3.5 per 100 person-years in patients with a wall thickness of 1 to 3.9 mm and 2.8 per 100 person-years in patients with a wall thickness of < 1 mm (P < 0.001). The overall incidence of vascular events was 26.0, 9.1, and 5.9 per 100 person-years of follow-up in the respective groups (P < 0.001). After adjustment for the presence of carotid stenosis, atrial fibrillation, peripheral arterial disease, and other risk factors, aortic plaques > or = 4 mm thick (including the thickness of the aortic wall) were found to be independent predictors of recurrent brain infarction (relative risk, 3.8; 95 percent confidence interval, 1.8 to 7.8; P = 0.0012) and of all vascular events (relative risk, 3.5; 95 percent confidence interval, 2.1 to 5.9; P < 0.001).

CONCLUSIONS: Atherosclerotic plaques > or = 4 mm thick in the aortic arch are significant predictors of recurrent brain infarction and other vascular events.