Cardiovascular Risk Factors Promote Brain Hypoperfusion Leading to Cognitive Decline and Dementia
Figure 1
Cardiovascular risk factors reported to promote progressive cognitive decline leading to dementia in the elderly population. Reduced cardiac output (<3.4 ± 0.5 L/min) in the absence of clinically identified stroke can promote hypotension, heart failure, hypoxia, and increased (↑) vascular resistance associated with cognitive decline [39, 42, 63, 64] and ostensibly, Alzheimer’s disease [173]. Aortic and mitral valve regurgitation (regurg) and/or valvular thickening can impair normal cardiac output. Aortic stiffening is associated with aging, hypertension, and atherosclerosis and is believed to result in brain microvascular damage, leading to cerebral hypoperfusion and cognitive decline [35, 118]. Left ventricular wall motion abnormalities mainly result from myocardial ischemia. Atrial fibrillation is a risk factor for cardioembolic events, especially stroke and for Alzheimer’s disease [71]; it is the most common arrhythmia in the elderly population. Epidemiologic and clinical evidence indicates that coronary artery disease, the leading cause of mortality in the United States, is a potential risk factor for Alzheimer’s disease [78, 109]. Left ventricular hypertrophy may be asymptomatic, mild, moderate, or severe and is a reported risk factor to cognitive decline in middle age but loses its predictive value in advanced age [174]. Presence of the ApoE4 allele, a genetic risk factor to Alzheimer’s dementia, increases the risk of coronary heart disease by about 40% [114]. Presence of two or more cardiovascular risk factors may significantly accelerate the onset of cognitive deficits [161].
