Subclinical Cardiovascular Disease and Death, Dementia, and CHD

Study Questions:

What is the relationship of subclinical coronary and other peripheral atherosclerosis to risk of death, dementia, and coronary heart disease (CHD) in the very elderly?

Methods:

The authors investigated the relationship between measures of subclinical cardiovascular disease (coronary artery calcium [CAC] score, carotid intimal medial thickness, stenosis, and ankle brachial index) and risk of dementia, CHD, and total mortality in 532 participants of the Cardiovascular Health Study-Cognition Study from 1998/1999 (mean age, 80 years) to 2012/2013 (mean age, 93 years).

Results:

At baseline, 36% of participants had CAC scores >400. Women and African-Americans had lower CAC scores and few men had low CAC scores. CAC score and number of coronary calcifications were directly related to age-adjusted total mortality and CHD. The age-specific incidence of dementia was higher than for CHD. Only about 25% of deaths were caused by CHD, 6% by stroke, and 16% by dementia. Approximately 64% of those who died had a prior diagnosis of dementia. In a Cox regression model, CAC scores >400 versus <10 were an independent significant predictor of total mortality for the entire sample (hazard ratio, 1.73; 95% confidence interval, 1.18-2.54). White women with low CAC scores had a significant delay in onset and decreased incidence of dementia. There was no signal of a relationship between CAC and risk of dementia in men. Traditional risk factors and measures of physical activity were not independent predictors of mortality.

Conclusions:

In participants ≥80 years of age, there is a greater incidence of dementia than of CHD. CAC, as a marker of atherosclerosis, is a determinant of mortality, and risk of CHD and myocardial infarction. White women with low CAC scores had a significantly decreased risk of dementia.

Perspective:

Dementia is more common in women than men, which may be related to longevity. Considering that two thirds of the very elderly had dementia and only one fourth died of CHD, as the authors suggest, a very important unanswered question is whether prevention of atherosclerosis and its complications is associated with less Alzheimer disease pathology and dementia.

Keywords: Alzheimer Disease, Ankle Brachial Index, Atherosclerosis, Cognition, Coronary Artery Disease, Coronary Stenosis, Dementia, Geriatrics, Mortality, Myocardial Infarction, Primary Prevention, Risk Factors, Stroke


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