Hypertension In The Elderly

Hypertension In The Elderly
Prof. Dr. Hussien H.rizk, MD
Prof. of Cardiology School of Medicine Cairo University
Hypertension is common in old age (>65), prevalence reaches 60-80% .
Framingham Heart Study showed that systolic BP falls after age 60 in both normotensive and untreated hypertensivs, and that isolated systolic hypertension accounts for 60% of cases of hypertension in the elderly .
Elevations in systolic and pulse pressures in this setting are due primarily to arterial stiffness .
OVERVIEW OF TREATMENT
The benefits of treating hypertension in thte elderly are well documented.
Many more elderly hypertensives should be actively treated to prevent serious morbidity , including stroke, heart failure and dementia.
Only a minority of the elderly with systolic hypertension are adequately treated .
Regardless of age, as long as the patient appears to have a reasonable life expectancy, active therapy is appropriate if the systolic. pressure is >160mmHg, with or without an elevated diastolic pressure.
Those at high risk for a cardiovascular event, such as diabetics or smokers, should be started on therapy at lower levels,probably>140 mmHg systolic. Factors in the elderly that may complicate therapy are decreased baroreceptor and sympathetic sensitivity and impaired cerebral autoregulation. Therapy should be gradual, avoiding drugs that may cause postural hypotension
LIFESTYLE MODIFICATIONS
Before initiating drug therapy, non-drug therapies may provide significant benefits. The ability of lifestyle changes to lower BP in the elderly is well documented.
Dietary sodium should be moderately restricted, since the pressor effect of sodium excess increases with age . The elderly may ingest more sodium to compensate for a decrease in taste sensitivity. They may depend more on processed, foods that are high in sodium rather than fresh foods that are low in sodium.
DRUG TREATMENT
If lifestyle changes are not enough, drug therapy should be
started following general principles Since postural and postprandial hypotension are found in as many as 30% of elderly patients with systolic hypertension when seated or supine, careful assessment and management of these problems must be provided before treatment of the hypertension.
RECOMMENDATIONS
Two principal issues must be considered in the medical treatment of these patients :
(1) which antihypertensive drugs should be used?; and
(2) what is the goal blood pressure?
In addition, several additional issues need to be emphasized:
● Lower initial doses (approximately one—half that in younger patients) should be used to minimize the risk of side effects.
● The reduction in BP should be gradual to minimize the risk of
ischemic symptoms, particularly in patients with postural hypotension.
● Studies showing benefit from the treatment of hypertension in the elderly were performed in relatively fit patients.
Greater caution should be applied to the therapy of more sick patients, and treatment may be stopped if postural hypotension is a problem.
CHOICE OF antihyperTENSIVE THERAPY
Old people are commonly living alone on a low fixed income, co-morbidity, polypharmacy and drug interactions and adverse effects are more common, particularly in ‘ view of border-line renal and hepatic function.
The preferred first-line drug in most elderly hyputensive patients is a thiazide diuretic.
Diuretics reduce the incidence of coronary and cerebrovascular disease and lower cardiovascular mortality . Treatment should begin with 12. 5 mg/day of hydrochlorothiazide.
The dose may be increased to a maximum of 25 mg/ day to minimize the risk of metabolic complications such as hypokalemia; a potassiumsparing diuretic such as amiloride can be added if the plasma potassium falls.
Two advantages of thiazide diuretics in older patients are low cost and the tendency to reduce urinary calcium excretion, leading to positive calcium balance and possibly decreased rates of bone loss and hip fracture. Data from the STOP-Hyperternsion-2
trial suggest that other antihypertensive drugs provide the same cardiovascular protection as thiazide diuretics.
In this study, 6614 elderly patients with a systolic pressure≥180mmHg and / or a diastolic pressure≥105mmHg were randomly assigned to one of three treatment groups: conventional therapy with beta blocker or diuretic; an ACE inhibitor (enalapril or lisinopril), or a dihydropyridine calcium channel blocker (felodipine or isradipine).
The degree of blood pressure control and the combined end point of fatal and nonfatal stroke or myocardial infarction and other cardiovascular mortality were the same in the three groups.
These observations tend to disprove previous concerns that beta blocker therapy in elderly hypertensive subjects may not provide as much cardiovascular protection as diuretics .
Thus, although low-dose thiazide therapy is generally preferred as initial therapy for hypertension in the elderly, other agents that lower the blood pressure can be added or substituted if necessary .
These general recommendations may be changed in special situalions. As examples :
● A diuretic should be used for heart failure or edema .
● A beta blocker should used in patients with coronary heart disease, tachyarrhytlhmias, and some patients with heart failure.
● An ACE inhibitor should be used in patients with heart failure due to systolic dysfunction, mild to moderate chronic renal disease, particularly diabetic nephropathy, or cardiovascular disease.
● A calcium channel blocker can be used in patients with angina pectoris,heart failure due to diastolic dysfunction, and peripheral vascular disease;in addition, verapamil can be given for tachyarrhythmias.
● The findings from the ALLHAT study that an alpha-blocker enhance the risk of heart failure (compared to therapy with a diuretic) should not preclude their
use in patients with hypertension and symptomatic prostatic enlargement or as an adjunct to diuretics.
With all drugs, orthostatic hypotension should be avoided because of the increased risk of falling in older patients. Sitting and 2 minute standing BP readings.
should be obtained in every visit.
Goal blood pressure : Recommended goals for the treatment are:
● A diastolic pressure of 85 to 90 mmHg in patients with diastolic hypertension.
● Ideally, a systolic pressure of 140 mmHg.
However, the question of how much BP should be reduced with antihypertensive therapy in elderly patients with systolic hypertension is uncertain in view of evidence that adverse outcomes are seen with low diastolic blood pressures.
● In the Rotterdam Study involving 2351 elderly hypertensives, the risk of stroke was significantly in treated patients whose diastolic pressure was > 65 mmHg compared with
those with a diastolic pressure between 65 and 74mm 74mmHg .
● In a reanalysis of data from the Systolic Hypertension in the Elderly program (SHEP), those who experienced a cardiovascular event while on antihypertensive drug therapy had slightly lower diastolic levels than those who did not have an event (65 versus 68mmHg).
Overall, a decrease of 5 mmHg in diastolic blood pressure (which initially averaged 77mmHg) in treated patients was associated with statistically significant increases in all cardiovascular events and in stroke. As a result, caution is advised when treating elderly patients with isolated systolic hypertension, who start with lower diastolic pressures. The diastolic blood pressure should not be reduced to less than 65 mmHg inelderly patients to attain the target systolic pressure . ln many cases, the level of systolic BP that is reached with two or three antihypertensive agents (even if greater than 140mmHg ) may be a reasonable goal in such individuals