Management of high blood pressure in the elderly

The elderly population is arbitrarily defined as individuals aged 65 years or above. The incidence of high Blood Pressure and its complications increase dramatically with age.
Human prospective research indicates that high Blood Pressure and ageing, both cause similar patterns of altered Cardiovascular structure, function and gene expression.
The interaction of mechanisms that underlie cardiac and vascular ageing with those that cause high Blood Pressure substantially modifies the high Blood Pressure expression as the organism age.
The population over age 65-years is increasing; the care of the elderly is becoming more important and rewarding.
Cardiovascular disease remains the leading cause of death and disability in this population group, and cardiovascular risk would continue to increase with age in the foreseeable future.
Traditionally, old age has been associated with sickness, dependence and lack of productivity.
This outdated notion does not reflect the reality. Indeed, most people adopt to change with age and remain independent well into old age.
In all countries of the world, older people make an important contribution to the society. It is very important, that the community should perceive ageing not as a problem but as a natural process.
Optimal management of these persons require a general understanding of the effects of ageing on the entire human organism and a specific understanding of the development of new treatments for cardiovascular disease in this population. Advanced age should never preclude appropriate therapy.
Aggressive medical and surgical approaches should be considered for select individuals.
High Blood Pressure affect up-to 50% of individuals 65 years of age or older. High Blood Pressure in the elderly usually confers 3 to 4-fold increased risk of Heart attacks and paralysis attacks, as compared to younger subjects.
A unified interpretation of cardiac changes that accompany advancing age in otherwise healthy person without clinically high Blood Pressure, suggests that the observed changes are adaptations to age-related cardiac and arterial changes.
In older individuals, specific patho-physiological mechanisms that underlie high Blood Pressure become superimposed on heart and vascular substrates, that are modified by an ageing process, per se.
Thus, an understanding of how ageing modifies cardiovascular structure and function is critical to an understanding of high Blood Pressure in the elderly.
The major age-related changes affecting the vessels are large arterial stiffening, which leads to increased systolic Blood Pressure.
There is usually a mild increase in resistance in small arteries. There is also increased left ventricular wall thickness and left ventricular cavity size. Modest focal increase in stiffer collagen fibres also occur.
These changes lead to impaired left ventricular ejection of Blood and reserve capacity which in turn leads to increased load on the heart and reduce myocardial contractility.
Chronic high Blood Pressure mimics accelerated ageing. There are parallel structural and functional changes in large arteries ie stiffness, cardiac mass ie hypertrophy and myocardial relaxation and filling ie diastolic left ventricular dysfunction, which occur in normotensive ageing and hypertensive people at any age.
In this regard, the traditional clinical distinction between normal Blood Pressure and high Blood Pressure is quite arbitrary, although it may be useful with regard to cardiovascular risk stratification.
In fact, the similarities between ageing and high Blood Pressure are so striking that ageing can be considered to be "Muted High Blood Pressure," while high Blood Pressure can be likened to "Accelerated Aging."
Some differences exist, however between high Blood Pressure and ageing. For example:
-- In contrast to a modest increase in resistance in normotensive ageing, in patients with high Blood Pressure, small vascular resistance increases more substantially. Increased peripheral vascular resistance plays a greater role in vascular loading of the left ventricle in patients with high Blood Press than in patients with normal Blood Pressure.
-- In older patients with high Blood Pressure resting stroke volume and cardiac output are not maintained at levels seen in younger patients with high Blood Pressure.
Isolated systolic high Blood Pressure represents the most common form of hypertension in the elderly. It is defined as, a systolic Blood Pressure above l60mmHg and Diastolic Blood Pressure below 95 or 90mmHg.
Its prevalence increases with advancing age, about two-thirds of individuals age 65 years or above have isolated systolic high Blood Pressure.
Typical of Isolated Systolic high Blood Pressure is a marked reduction in arterial compliance which has recently been shown to involve both elastic - muscle conduit arteries.
Age-related changes in aortic stiffness explain the frequent development of Isolated Systolic high Blood Pressure.
Arterial stiffening and loss of distensibility in large arteries and aorta leads to a progressive elevation in Systolic Blood Pressure, whereas Diastolic Blood Pressure elevation is caused by constriction of small arteries and arterioles.
The changes in arterial wall are due both to increase in Blood Pressure itself and to the active response of arterial wall to this increase in pressure.
The elevated systolic Blood Pressure increases left ventricular workload and may cause left ventricular hypertrophy, whereas decreased Diastolic Blood Pressure may compromise coronary Blood flow.
Thus, the increase in Systolic Blood Pressure and decrease in diastolic Blood Pressure lead to a dual phenomenon: a hypertrophied heart and inadequately perfuse coronary arteries, increasing the likelihood of myocardial infarction, stroke and cause mortality.
At this stage the left ventricular ejection occurs against a much stiffer and thicker aorta, thereby increasing systolic Blood Pressure.
Aged Heart has difficulty in maintaining cardiac output against a high after-load in the face of impaired contractility. At about the age of 50 years, blood flow during diastole is increased due to stiff arteries and hence leads to an abnormal decrease in Diastolic Blood Pressure.
After the age of 65 years the diastolic Blood Pressure tends to decrease markedly and results in a pure isolated systolic hypertension.
Blood Pressure is more variable in the older patients and Blood Pressure measurements confer special problems in the elderly.
Pseudo hypertension occurs in an atherosclerotic artery that is compressible, and therefore gives a false high Blood Pressure reading, in these people very rigid and calcified arteries cannot collapse under the cuff bladder giving rise to falsely high readings, it is an over estimation of actual intra-arterial Blood Pressure.
Recently an International organisation named "Global Embrace 2002" has been launched with the slogan "Active Aging: Moving Hearts For Health." Global Embrace is the annual advocacy event, which consists of a chain of locally organised walks and other activities in member countries involving elderly population.
WHO has also launched a new policy frame-work on active ageing defined as "the process of optimising opportunities for health, participation and security in order to enhance peoples' quality of life as they age.
Clinically it has been established that the reduction of systolic Blood Pressure in the elderly is accompanied by a reduction of cardiovascular mortality and morbidity as follows:
DECREASE RATE OF STROKE EVENTS: 32 percent.
DECREASE RATE OF HEART ATTACKS: 16 percent.
DECREASE PROGRESSION TO CONGESTIVE CARDIAC FAILURE: 54 percent.
Systolic Blood Pressure is the major target for improving outcomes in the elderly patients.
It has been suggested that alterations in cardio vascular function that exceeds the identified limits for age-related changes for healthy elderly individuals are most likely manifestations of activation of ageing with age associated with changes of physical de-conditioning.
Specific cardiovascular changes that occur during ageing in health perhaps should not truly be considered to reflect a normal process, because they are so similar to those seen in Hypertension and other risk factors that merit intervention.
However, systolic Blood Pressure over 200mmHg and diastolic Blood Pressure over 95mmHg are always abnormal.
No matter what the age. Arteriosclerosis, serum cholesterol and cigarette smoking play their roles in determining the extent of atherosclerosis.
Evidence based benefits of therapy in the elderly must include life style modifications.
Reducing Sodium intake and weight reduction are particularly beneficial for control of Blood Pressure and often reduce the need for pharmacological therapy.
Elderly should be encouraged for life cycle changes not only to control Blood Pressure but also to improve quality of life.
In a clinical research trial, restricting salt to 2gms/day favourably reduced systolic and diastolic Blood Pressure and also 40% of these patients were able to discontinue their medication.
Weight reduction and salt restriction, when used together decreased the need for anti-hypertensive therapy in almost half of the participants.
Regular moderate exercise have been shown to be effective in improving left ventricular ejection capacity, reduction in cardiac after load via reduced arterial stiffness and weight reduction.
They should be encouraged to stop alcohol and smoking and avoid psychosocial stress. Result orientated dietary changes would be very important, which include:
-- Try to maintain total cholesterol <200mg/dl.
-- LDL - cholesterol < 100mg/dl.
-- HDL - cholesterol> 39mg/dl.
-- TG < 150mg/dl.
-- Fasting Blood Sugar < 110mg/dl.
As hypertension is "a state of altered haemodynamics," drug selection should be appropriate for the underlying haemodynamic abnormality such as arterial stiffening.