Contemporary Reviews in Cardiovascular Medicine Cellular Senescence, Vascular Disease, and Aging Part 2 of a 2-Part Review: Clinical Vascular Disease in the Elderly

The increasing prevalence of older-age people in our society represents the culmination of centuries of medical, scientific, and social endeavors. At least in Western society, now relatively freed from pestilence, abject poverty, gross malnutrition, and polluted water and food sources, an increasing proportion of the population can expect to make it to old age. However, although US age-adjusted death rates from cardiovascular disease, coronary heart disease, and stroke continue to fall, a disproportionate number of people who reach old age (80% of people aged 80 years) suffer from these diseases.1a In this 2-part review, we consider important pathobiological changes that occur with aging in the cardiovascular system, exploring promising areas of recent scientific progress and novel insights that may be translatable into targeted clinical strategies to help to alleviate the excess morbidity and mortality imposed by cardiovascular disease in the elderly. In this second installment, we focus specifically on vascular disease states of the elderly, including systolic hypertension, vascular calcification, and dementia, and we review relevant basic and clinical discoveries that further elucidate these conditions. Hardening of the Arteries: Calcification, Glycosylation, and the Vasculature in Old Age The Elderly Vascular Phenotype Aging is associated with various changes in the vascular system at differing structural and functional levels. At the macroscopic level, an increase in arterial lumen size and arterial wall thickening, mainly of the intima, are observed. 2 In addition, increased vascular calcification and a generalized stiffening of the arterial tree lead to increased arterial wave reflectance, increased systolic blood pressure, decreased diastolic blood pressure, and a widened pulse pressure. An interesting aspect of vascular biology in which significant inroads have been made is our understanding of pulse wave velocity, which is partly a consequence and partly a cause of the elderly vascular phenotype. In the healthy human arterial tree, the arterial pulse wave is reflected back toward the heart from branch points and other structures in the peripheral circulation, with the reflected wave arriving back at the aortic root during diastole. In older people, the stiffening of the vasculature results in higher forward and reflected pulse wave velocities, with the reflected wave arriving back at the aortic root in late systole, leading to an augmentation of the late systolic pressure (Figure 1). 3 This