Hypertension in the elderly: Some practical considerations
ABSTRACTData from randomized controlled trials suggest that treating hypertension in the elderly, including octogenarians, may substantially reduce the risk of cardiovascular disease and death. However, treatment remains challenging because of comorbidities and aging-related changes. We present common case scenarios encountered while managing elderly patients with hypertension, including secondary hypertension, adverse effects of drugs, labile hypertension, orthostatic hypotension, and dementia.
KEY POINTS
- Therapy should be considered in all aging hypertensive patients, even the very elderly (> 80 years old).
- Most antihypertensive drugs can be used as first-line treatment in the absence of a compelling indication for a specific class, with the possible exception of alpha-blockers and beta-blockers.
- An initial goal of less than 140/90 mm Hg is reasonable in elderly patients, and an achieved systolic blood pressure of 140 to 145 mm Hg is acceptable in octogenarians.
- Start with low doses; titrate upward slowly; and monitor closely for adverse effects.
- Thiazide diuretics should be used with caution in the elderly because of the risk of hyponatremia.
The management of hypertension has advanced significantly in the last few decades. But the race for more effective means to control this epidemic and its associated complications is far from won. A high percentage of patients in the United States have hypertension that is uncontrolled. Most of these belong to the most rapidly growing demographic group in the United States, ie, the elderly.
It is estimated that more than 70% of medical practice will be directed to geriatric needs in the coming years. It is therefore very important for clinicians to be comfortable with managing hypertension in the elderly.
A GROWING PROBLEM IN AN AGING POPULATION
Between 1980 and 2009, the US population age 65 and older increased from 25.6 million to 39.6 million, of which 42% are men and 58% women.1 This number is expected to reach 75 million by the year 2040. People over 85 years of age are the fastest growing subset of the US population.2 As many as 50% of people who were born recently in countries such as the United States, the United Kingdom, France, Denmark, and Japan will live to celebrate their 100th birthday.3
According to the Framingham Heart Study, by age 60 approximately 60% of the population develops hypertension, and by 70 years about 65% of men and about 75% of women have the disease. In the same study, 90% of those who were normotensive at age 55 went on to develop hypertension. The elderly also are more likely to suffer from the complications of hypertension and are more likely to have uncontrolled disease.
Compared with younger patients with similar blood pressure, elderly hypertensive patients have lower cardiac output, higher peripheral resistance, wider pulse pressure, lower intravascular volume, and lower renal blood flow.4 These age-related pathophysiologic differences must be considered when treating antihypertension in the elderly.
IS TREATING THE ELDERLY BENEFICIAL?
Most elderly hypertensive patients have multiple comorbidities, which tremendously affect the management of their hypertension. They are also more likely than younger patients to have resistant hypertension and to need multiple drugs to control their blood pressure. In the process, these frail patients are exposed to a host of drug-related adverse effects. Thus, it is relevant to question the net benefit of treatment in this age group.
Many studies have indeed shown that treating hypertension reduces the risk of stroke and other adverse cardiovascular events. A decade ago, Staessen et al,5 in a meta-analysis of more than 15,000 patients between ages 62 and 76, showed that treating isolated systolic hypertension substantially reduced morbidity and mortality rates. Moreover, a 2011 meta-analysis of randomized controlled trials in hypertensive patients age 75 and over also concluded that treatment reduced cardiovascular morbidity and mortality rates and the incidence of heart failure, even though the total mortality rate was not affected.6
Opinion on treating the very elderly (≥ 80 years of age) was divided until the results of the Hypertension in the Very Elderly trial (HYVET)7 came out in 2008. This study documented major benefits of treatment in the very elderly age group as well.
The consensus, therefore, is that it is appropriate, even imperative, to treat elderly hypertensive patients (with some cautions—see the sections that follow).
GOAL OF TREATMENT IN THE ELDERLY
Targets for blood pressure management have been based primarily on observational data in middle-aged patients. There is no such thing as an ideal blood pressure that has been derived from randomized controlled trials for any population, let alone the elderly. The generally recommended blood pressure goal of 140/90 mm Hg for elderly hypertensive patients is based on expert opinion.
Moreover, it is unclear if the same target should apply to octogenarians. According to a 2011 American College of Cardiology/American Heart Association (ACC/AHA) expert consensus report,8 an achieved systolic blood pressure of 140 to 145 mm Hg, if tolerated, can be acceptable in this age group.
An orthostatic decline in blood pressure accompanies advanced age and is an inevitable adverse effect of some antihypertensive drugs. Accordingly, systolic blood pressure lower than 130 and diastolic blood pressure lower than 70 mm Hg are best avoided in octogenarians.8 Therefore, when hypertension is complicated by coexisting conditions that require a specific blood pressure goal, it would seem reasonable to not pursue the lower target as aggressively in octogenarians as in elderly patients under age 80.
Having stated the limitations in the quality of data at hand—largely observational—it is relevant to mention the Systolic Blood Pressure Intervention trial (SPRINT).9 This ongoing randomized, multicenter trial, launched by the National Institutes of Health, is assessing whether maintaining blood pressure levels lower than current recommendations further reduces the risk of cardiovascular and kidney diseases or, in the SPRINT-MIND substudy, of age-related cognitive decline, regardless of the type of antihypertensive drug taken. Initially planning to enroll close to 10,000 participants over the age of 55 without specifying any agegroup ranges, the investigators later decided to conduct a substudy called SPRINT Senior that will enroll about 1,750 participants over the age of 75 to determine whether a lower blood pressure range will have the same beneficial effects in older adults.
Given the limitations in the quality and applicability of published data (coming from small, nonrandomized studies with no long-term follow-up), SPRINT is expected to provide the evidence needed to support standard vs aggressive hypertension control among the elderly. The trial is projected to run until late 2018.
