Systolic hypertension in the elderly

Abstract

Historically diastolic blood pressure (BP) rather than systolic BP has been regarded clinically as the more important component related to subsequent hypertensive morbidity and mortality, and treatment has thus been directed towards lowering the diastolic BP. Observational studies across many different populations have related cerebrovascular disease and death more to the systolic BP, which appears selectively to increase as the population ages. Isolated systolic hypertension (ISH), therefore, may be more prevalent as westernized societies become older. Those affected with ISH suffer a two- to fivefold increase in rates of stroke and ischemic heart disease compared to normotensives. Currently no clinical trials data exist for ISH showing the efficacy of antihypertensive therapy upon final morbidity and mortality, but a large-scale multicenter clinical trial, the Systolic Hypertension in the Elderly Program (SHEP), is currently underway in the United States. Results are expected in the early 1990s. If the results of this trial confirm the efficacy of treating ISH, the therapeutic challenge of ISH will be to selectively decrease systolic BP without undue side effects.

Correlates of blood pressure in community-dwelling older adults. The Cardiovascular Health Study. Cardiovascular Health Study (CHS) Collaborative Research Group.

“…These associations may seem contradictory to known associa- tions between BP and cardiovascular disease. There are several likely explanations: myocardial damage or dysfunction associated with CHD and CHF causes reduced cardiac output and lowered BP; hypertension would likely be aggressively treated in these individuals, resulting in lower BP; many medications given for these conditions, such as /3-blockers and vasodilators, lower BP; and although the results of the Systolic Hypertension in the Elderly Program indicate that systolic hypertension is causally related to stroke and CHD in the elderly, 17 perhaps DBP does not have the same risk as in younger populations, given the fact that older people tend to have lower DBP. Another possibility is that people with higher DBP die before reaching old age.…”

“…Much of the systolic hypertension seen in elderly subjects probably results from degenerative changes in the large arterial blood vessels. 17 In youth, the elasticity of these vessels allows them to become distended during systole, but aging is usually accompanied by calcification and decreased elasticity. A given stroke volume therefore results in a greater increase in SBP in old age than in youth.…”