Aortic, Cardiovascular Disease and Silent Brain Infarcts

Columbia University Health Sciences, New York NY

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Abstract

DESCRIPTION (provided by applicant): Subclinical brain infarcts, detected by MRI, are highly prevalent in the elderly population. Their significance as predictors of symptomatic stroke or other vascular events is controversial. The risk factors for silent brain infarcts are poorly understood, and very little is known on the relationship between silent infarcts and aortic, cardiac or 24-hour blood pressure abnormalities, which are known to be strongly associated with symptomatic stroke. In the first cycle, we demonstrated the role of large aortic plaques as independent stroke risk factors in the elderly, and the role of coagulation and lipid abnormalities as co-factors in increasing the stroke risk. The competing continuation will focus on subclinical brain infarcts and their relationship with aortic, subclinical cardiac abnormalities and 24-hour blood pressure abnormalities, in an attempt to identify subjects at increased risk of symptomatic stroke, myocardial infarction and vascular death. A cross-sectional study with prospective follow-up is proposed on 900 stroke-free volunteers over the age of 60 with the following aims: 1) To determine if aortic abnormalities are independently associated with silent brain infarcts in the elderly after adjusting for conventional vascular risk factors. 2) To determine if cardiac abnormalities are independently associated with silent brain infarcts in the elderly after adjusting for conventional vascular risk factors. 3) To determine if 24-hour blood pressure abnormalities are associated with silent brain infarcts in the elderly after adjusting for conventional vascular risk factors. 4) To determine if aortic, cardiac and 24-hour blood pressure abnormalities are independently associated with future risk of vascular events and death. All subjects will undergo head MRI for subclinical brain disease detection as part of the Northern Manhattan Study (NOMAS), an arrangement that will guarantee enrollment and greatly increase the efficiency of the present application. Proximal aortic abnormalities and cardiac abnormalities will be assessed by transthoracic echocardiography with a novel 3-dimensional transthoracic imaging. 24-hour ambulatory blood pressure monitoring will also be performed. Odds ratio for aortic/cardiac/24-hour blood pressure abnormalities and silent brain infarcts will be calculated by logistic regression analysis in the overall population and in race-ethnic subgroups, adjusting for other stroke risk factors. Subjects will be followed by annual telephone interviews to ascertain stroke, myocardial infarction, and death. The present application will help fill gaps in knowledge on silent brain infarcts and their risk factors in the elderly, and identify subjects at higher risk before a symptomatic stroke or other vascular event occurs.