Age and Ageing (1979), 8, 115
SYMPOSIUM ON HYPERTENSION IN THE ELDERLY*
SHOULD WE TREAT HYPERTENSION IN THE ELDERLY? BERNARD ISAACS
Department of Geriatric Medicine, University of Birmingham, Queen Elizabeth Hospital, Birmingham B15 2TH
Summary The argument for treating hypertension in old people is essentially that the treatment is beneficial in young people. Direct evidence of benefit in old people is limited. Further evidence is awaited from the European Cooperative Study. Critical examination of the indirect evidence gives limited support to treatment of certain sub-groups of the elderly only. Much present practice appears to be unsound. TREATMENT OF HYPERTENSION IN PATIENTS UNDER THE AGE OF 65
The treatment of essential hypertension in patients under the age of 65 is firmly established on the basis of: 1. evidence of an association between hypertension and risks to life and health; 2. evidence of reduction in these risks by effective treatment in controlled trials. There is however evidence that treatment in practice often falls far short of what is desirable. Definitions
In accordance with the modern view that the level of systolic and diastolic blood pressure represents a continuum, hypertension is not defined in this article. The evidence examined is confined to that relating the level of blood pressure with risk. The article deals only with so-called 'essential' hypertension and not with that secondary to specific causes; the latter are in any case extremely rare in old age. It is further assumed that hypertension is not in itself a cause of symptoms in the elderly: a discussion of this point is outside the scope of the present paper. The 'symptoms' of hypertension which may be referred to are stroke, hypertensive heart failure, and hypertensive retinopathy of grade III or IV. Renal disease secondary to hypertension is considered to be a contraindication to treatment. The case for treatment
The abundant evidence Unking the level of systolic and diastolic blood pressure with death from all causes, death from cardiovascular disease, incidence of stroke and incidence of coronary artery disease has been reviewed by Kannel (1976a). The stroke• Leicester, 20 October 1978.
116
Symposium on Hypertension in the Elderly
related risks are emphasized especially by Paul (1971) and by Kannel et al. (1970). The evidence Unking hypertension and myocardial infarction is suggestive rather than conclusive (Miall & Chinn 1974). Numerous well-controlled trials show that antihypertensive therapy reduces the risk of death (Breckenridge et al. 1970, Storm-Mathisen et al. 1973) and of stroke (Beevers et al. 1973a). These effects have been demonstrated in moderately and severely hypertensive men and women (Hamilton et al. 1964, Veterans Administration Co-operative Study Group 1967), in pregnant women (Leather et al. 1968) and in survivors of stroke (Carter 1970, Hypertensive-Stroke Co-operative Study Group 1974, Medical Research Council Working Party on Mild to Moderate Hypertension 1977). The reduction of the risk of stroke has been shown to be proportional to the effectiveness of treatment (Beevers et al. 19736). The effectiveness of treatment in reducing the risks of coronary heart disease was shown in one study (Berglund et al. 1978) but not in others (Breckenridge et al. 1970, M.R.C. 1977). Compliance with treatment was obtained in most patients in the special trials and sideeffects of treatment were infrequently prohibitive. However, compliance in the conditions of general practice in the United Kingdom, even in the younger age group, is much less satisfactory. TREATMENT OF HYPERTENSION IN PATIENTS AGED 65 AND OVER
The case for treating essential hypertension in patients aged 65 and over is less firmly based. Not only is the evidence conflicting and insufficient, but there are doubts about the case for treatment a priori. The argument a priori
Doubt has been cast on whether essential hypertension in those aged 65 and over is a disease; and if so whether it is the same disease as occurs in younger subjects. The argument runs that if hypertension is a lethal disease, then it might be expected that the average blood pressure of population groups will fall with increasing age, as a result of progressive elimination of those at highest risk (Smith 1957). In fact it has been known since before anti-hypertensive treatment was in wide use (Master et al. 1958, Society of Actuaries 1959, Anderson & Cowan 1959, 1972) that average blood pressure rises with age. Indeed in a group of healthy people aged 90 and over, half of the men and threequarters of the women had systolic blood pressure in excess of 160 mmHg (Danner et al. 1978). Does this mean, as suggested by Smith (1957), that for some people a high blood pressure in younger life confers survival value? Or does it mean that some people with a relatively low blood pressure in earlier life acquire a higher blood pressure as they grow older? In the former group antihypertensive therapy might be contra-indicated; while in the latter group, as Kannel (1976a) has shown, the rise in blood pressure is associated with increasing risk of damage and should presumably be treated. It is not always possible to distinguish, amongst elderly people with high blood pressure, those whose pressure has been rising; and to treat all hypertensives over the age of 65 without attempting to distinguish the two groups might mean exposing some to potential harm. THE RISKS OF HYPERTENSION IN THE ELDERLY
The evidence that high blood pressure in the elderly is harmful is fragmentary and conflicting. The evidence is very much stronger for patients aged 65-74 than it is for
Symposium on Hypertension in the Elderly
117
those aged 75 and over. The main source of our information on the former group is the Framingham Study; and, as has frequently been pointed out, there are genetic and environmental differences between the population of Framingham and that of the United Kingdom. The Framingham Study shows that for men and women aged 65-74 the risks of death from all causes and death from cardiovascular disease are twice as high for persons with systolic pressures of 160 and over as they are for those with systolic pressures of 130 and less (Kannel 1976a). There are also increased risks in those with high blood pressure in this age group of sudden death, myocardial infarction, congestive cardiac failure and coronary heart disease (Kannel 1976A). The Veterans Administration Study (1972) likewise found a high incidence of stroke, congestive cardiac failure and coronary artery disease in men aged 60 and over with diastolic blood pressure of 90114 mmHg. Data from the Rutherglen Clinic in Scotland showed that in men and women aged 70 and over there was an inverse relationship between the level of systolic blood pressure and survival, but this effect was weak. In women, but not in men, the diastolic blood pressure was directly related to survival; i.e. the higher the pressure the less was the risk to life (Anderson & Cowan 1976). In a London general practice the observed mortality rate amongst old people with elevated blood pressure was equal to or less than the rate predicted from life tables (Fry 1974). THE EFFECTIVENESS OF ANTI-HYPERTENSIVE TREATMENT IN THE ELDERLY
Despite the large number of elderly patients treated with antihypertensive drugs little acceptable evidence of effectiveness is yet available. In the Veterans Administration Cooperative Study (1972) of men aged 60 and over with diastolic blood pressure of 90-114 mmHg the incidence of strokes, congestive cardiac failure and coronary artery disease was halved in treated patients compared with controls. Waldek (1977) showed some improvement in a few elderly patients with left ventricular failure and retinopathy. Jackson et al. (1976), in an uncontrolled report, described serious symptoms occurring in elderly patients injudiciously treated with large and inappropriate doses of drug. A European Working Party on high blood pressure in the elderly has been established and has shown the feasibility of a large-scale clinical trial (Amery & de Schaepdryver 1973, Amery et al. 1977). This trial will supply some answers to our questions, but it will be some years before its results are available. TOLERANCE OF ELDERLY PATIENTS TO ANTIHYPERTENSIVE TREATMENT
Doctors who are reluctant to use antihypertensive therapy in elderly hypertensive patients are concerned about the effects of lowering blood pressure on cerebral blood flow. In normal people the autoregulatory mechanism maintains cerebral blood flow constant, despite fluctuations in blood pressure, until mean arterial pressure falls to about 60 mmHg (Taylor 1976). In hypertensive subjects the lower limit of autoregulation rises, and sharp falls in blood pressure may be associated with reduced cerebral perfusion (Strangaard et al. 1973). This mechanism is thought to be responsible for dizzy turns, light-headedness, falls, and even transient ischaemic attacks and strokes in elderly patients on antihypertensive therapy (Graham 1975, Jackson et al. 1976). Elderly
118
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hypertensive patients may be particularly sensitive to this mechanism, and even quite small reductions in blood pressure may significantly affect cerebral blood flow. Indeed small reductions in blood pressure induced by postural change have been shown to reduce cerebral blood flow in patients who developed symptoms of postural hypotension, but not in those who experienced a postural fall in blood pressure without symptoms (Wollner & McCarthy 1978). Studies of falls in old people living at home showed that those who fell took only slightly more anti-hypertensive drug compared with an agematched control group (Reinhold & Isaacs, unpublished). PRESCRIBING HABITS
The current prescribing scene, as reviewed by Hart (1975) and by Kannel (1976&), must cause dismay to those who would wish to see medical treatment practised rationally. The benefits of antihypertensive treatment in younger patients are very well attested: those in older patients are dubious. The risks of hypertension are greater in the male and less in the female. Nonetheless those most likely to be receiving antihypertensive medication are females over the age of 65 (Miall & Chinn 1974, Heller & Rose 1977). Older patients are more likely to have their blood pressure recorded than are younger ones (Hodes et al. 1975); and this may have something to do with the fact that older people are more likely to have older doctors. More than five million prescriptions for antihypertensive treatment are written each year in the United Kingdom (Hart 1977) and we really do not know how much good or how much harm they may be doing. It is perhaps reassuring that the amount of harm that they might do is limited by the fact that only a fraction of these drugs are actually consumed by the people for whom they are prescribed (Law & Chalmers 1976, Shaw & Opit 1976, Atkinson et al. 1977). GUIDANCE
The following guidance to prescribers is based partly on such evidence as there is, and partly on the author's prejudices. 1. Men aged 65-74 with systolic blood pressure in excess of 160 mmHg or diastolic blood pressure in excess of 90 mmHg, with or without a history of stroke or symptoms of hypertensive heart disease or progressive hypertensive retinal disease should receive antihypertensive therapy provided that: a. compliance with treatment is assured; b. blood pressure is lowered gently, preferably by a thiazide; c. disturbing side-effects do not occur. Treatment and compliance should be carefully monitored. If the patient survives to the age of 75 treatment should probably be discontinued then. 2. Women aged 65-74 with similar levels of blood pressure and with symptoms of hypertensive heart disease or retinal disease should receive treatment with similar provisos. Those without symptoms should not be treated, unless there is evidence of rapidly rising blood pressure. 3. For men and women aged 75 and over antihypertensive treatment should be prescribed only for the control of hypertensive heart failure; and for the very rare case
Symposium on Hypertension in the Elderly
119
of progressive hypertensive retinal damage. Symptomless patients should not be treated, no matter how high the level of the blood pressure. These guidelines will doubtless be revised as further facts become available. CONCLUSION
The prescribing of potent antihypertensive drugs to every elderly person with a high blood pressure will benefit a few, will harm many, and will be wholly irrelevant to the medical needs of most, especially of those in whom the high blood pressure is an incidental finding and is not the cause of the symptoms for which the patient has sought medical help. We still do not know in which elderly patients hypertension is a disease and in which it is, like old age itself, an achievement. Doctors are advised to curtail antihypertensive therapy in the elderly until much more is known about its effects. May I conclude by quoting Sir Francis Bacon: 'This subject of man's body is of all other things in nature most susceptible of remedy; but then that remedy is most susceptible of error. For the same subtlety of the subject doth cause large positivity and easy failing; and therefore the inquiry ought to be the more exact.' REFERENCES AMERY, A., BERTHAUX, P., BIRKENHAGER, W., BULPITT, C, CLEMENT, D., DE SCHAEPDRYVER, A., DOLLERY, C, ERROULD, H., FAGARD, R., FORETTE, F., HELLEMANS, J., KHO, T., LUNDJOHANSEN, P., MEURICE, J. & PIERQUIN, L. (1977) Antihypertensive therapy in elderly patients:
pilot trial of the European Working Party on High Blood Pressure in the Elderly. Gerontology 23, 426-37. AMERY, A. & DE SCHAEPDRYVER, A. (1973) Organisation of a double-blind multicentre trial on antihypertensive therapy in elderly patients. European Working Party on High Blood Pressure in Elderly. Clin. Sci. Mol. Med. 45, 71-3S. ANDERSON, W. F. & COWAN, N. R. (1959) Arterial pressure in healthy older people. Clin. Sci. 18, 103-18. ANDERSON, W. F. & COWAN, N. R. (1972) Arterial blood pressure in healthy older people. Gerontol. Clin., 14, 129-36. ANDERSON, W. F. & COWAN, N. R. (1976) Survival of healthy older people. Br. J. Prev. Soc. Med. 30, 231-2. ATKINSON, L., GIBSON, I. I. J. M. & ANDREWS, J. (1977) The difficulties of old people taking drugs. Age & Ageing 6, 144-50. BEEVERS, D. G., FAIRMAN, M. J., HAMILTON, M. & HARPUR, J. E. (1973a) The influence of antihypertensive treatment on the incidence of cerebrovascular disease. Postgrad. Med. J. 49, 905-7. BEEVERS, D. G., FAIRMAN, M. J., HAMILTON, M. & HARPUR, J. E. (19736) Antihypertensive treatment and the course of established cerebrovascular disease. Lancet i, 1407-9. BERGLUND, G., WILHELMSEN, L., SANNERSTEDT, R., HANSSON, L., ANDERSSON, O., SILVERTSSON, R., WEDEL, H. & WIKSTRAND, J. (1978) Coronary heart disease after treatment of hypertension.
Lancet i, 1-5. A., DOLLERY, C. T. & PARRY, E. N. O. (1970) Prognosis of treated hypertension, changes in life expectancy and causes of death between 1952 and 1967. Q.J. Med. 39, 411-29. CARTER, A. B. (1970) Hypertensive therapy in stroke survivors. Lancet i, 485-9. DANNER, S. A., DE BEAUMONT, M-J. & DUNNING, A. J. (1978) Cardiovascular health in the tenth decade. Br. Med. J. 2, 663. FRY, J. (1974) Natural history of hypertension: a case for selective non-treatment. Lancet ii, 431-3.
BRECKENRIDGE,
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D. I. (1975) Ischaemic brain damage of central perfusion type after treatment of severe hypertension. Br. Med. J. 4, 739. HAMILTON, M., THOMPSON, E. N. & WISNIEWSKI, T. K. M. (1964) The role of blood pressure control in preventing complications of hypertension. Lancet i, 235-8. HART, J. T. (1975) The management of high blood pressure in general practice. J. R. Coll. Gen. Pract. 25, 160-92. HART, J. T. (1977) Pressure on people. Br. Med.J. 1, 1462-3. HELLER, R. F. & ROSE, G. (1977) Current management of hypertension in general practice. Br. Med.J. 7,1442-4. HODES, C , ROGERS, P. A. & EVERITT, M. G. (1975) High blood pressure: detection and treatment by general practitioners. Br. Med. J. 2, 674-7. Hypertensive-Stroke Co-operative Study Group (1974) Effect of antihypertensive treatment on stroke recurrence. J. Am. Med. Assoc. 229, 409-18. JACKSON, G., PIERSCIANOWSKI, T. A., MAHON, W. & LONDON, J. (1976) Inappropriate antihypertensive therapy in the elderly. Lancet it, 1317-8. KANNEL, W. B., WOLF, P. A., VERTER, J. & MCNAMARA, P. M. (1970) Epidemiologic assessment of the role of blood pressure in stroke: the Framingham study. J. Am. Med. Assoc. 214, 301—10. KANNEL, W. B. (1976a) Blood pressure and the development of cardiovascular disease in the aged. pp. 143-75. In: Cardiology in Old Age Ed.: F. I. Caird, J. L. C. Dall & R. D. Kennedy. New York and London: Plenum Press. KANNEL, W. B. (19766) The Framingham Study. Br. Med. J. 2, 1255. LAW, R. & CHALMERS, C. (1976) Medicines and elderly people: a general practice survey. Br. Med.J. 1, 565-8. LEATHER, H. M., HUMPHREYS, D. M., BAKER, P. & CHADD, M. A. (1968) A controlled trial of antihypertensive agents in hypertension in pregnancy. Lancet ii, 488-90. MASTER, A. M., LASSER, R. P. & JAFFE, H. L. (1958) Blood pressure in white people over 65 years of age. Am. Intern. Med. 48, 284-99. Medical Research Council Working Party on Mild to Moderate Hypertension (1977) Randomised controlled trial of treatment for mild hypertension: design and pilot trial. Br. Med. J. 1, 1437-40. MIALL, W. E. & CHFNN, S. (1974) Screening for hypertension: some epidemiological observations. Br. Med. J. 3, 595-600. PAUL, O. (1971) Risks of mild hypertension: a ten-year report. Br. Health J. (Suppl.) 33, 116-21. SHAW, S. M. & OPIT, L. J. (1976) Need for supervision in the elderly receiving long-term prescribed medication. Br. Med. J. 1, 505-7. SMITH, J. M. (1957) Genetic variations in ageing, pp. 115-122. In: The Biology of Ageing Ed.: W. B. Yapp & G. H. Bourne. London: Institute of Biology. Society of Actuaries (1959) Build and Blood Pressure Study Vol. 1. Chicago: Society of Actuaries. STORM-MATHISEN, H., LOKEN, H. & RIAN, V. (1973) Complications in treated hypertension. Clin. Sci. Mol. Med. 45, 205-8S. STRANDGAARD, S., OLESEN, J., SKINHOJ, E. & LASSEN, V. A. (1973) Autoregulation of brain circulation in severe arterial hypertension. Br. Med. J. 1, 507-10. TAYLOR, D. E. M. (1976) Factors affecting cerebral blood flow. pp. 128-41. In: Stroke Ed.: F. J. Gillingham, C. Mawdsley & A. E. Williams. Edinburgh: Churchill Livingstone. Veterans Administration Co-operative Study Group on Antihypertensive Agents (1967). Effect of treatment on morbidity in hypertension: results in patients with diastolic blood pressures averaging 115 through 129 mmHgJ. Am. Med. Assoc. 202, 1028-34. Veterans Administration Co-operative Study Group on Antihypertensive Agents (1972) Effects of treatment on morbidity in hypertension: III. Influence of age, diastolic pressure, and prior cardiovascular disease: further analysis of side effects. Circulation 45, 991-1004. WALDEK, S. (1977) Hypertension in the elderly. Lancet i, 1055. WOLLNER, L. & MCCARTHY, S. T. (1978) Failure of autoregulation as a cause of brain dysfunction in the elderly. Paper read at meeting of British Geriatrics Society, London. GRAHAM,
SYMPOSIUM ON HYPERTENSION IN THE ELDERLY*
SHOULD WE TREAT HYPERTENSION IN THE ELDERLY? BERNARD ISAACS
Department of Geriatric Medicine, University of Birmingham, Queen Elizabeth Hospital, Birmingham B15 2TH
Summary The argument for treating hypertension in old people is essentially that the treatment is beneficial in young people. Direct evidence of benefit in old people is limited. Further evidence is awaited from the European Cooperative Study. Critical examination of the indirect evidence gives limited support to treatment of certain sub-groups of the elderly only. Much present practice appears to be unsound. TREATMENT OF HYPERTENSION IN PATIENTS UNDER THE AGE OF 65
The treatment of essential hypertension in patients under the age of 65 is firmly established on the basis of: 1. evidence of an association between hypertension and risks to life and health; 2. evidence of reduction in these risks by effective treatment in controlled trials. There is however evidence that treatment in practice often falls far short of what is desirable. Definitions
In accordance with the modern view that the level of systolic and diastolic blood pressure represents a continuum, hypertension is not defined in this article. The evidence examined is confined to that relating the level of blood pressure with risk. The article deals only with so-called 'essential' hypertension and not with that secondary to specific causes; the latter are in any case extremely rare in old age. It is further assumed that hypertension is not in itself a cause of symptoms in the elderly: a discussion of this point is outside the scope of the present paper. The 'symptoms' of hypertension which may be referred to are stroke, hypertensive heart failure, and hypertensive retinopathy of grade III or IV. Renal disease secondary to hypertension is considered to be a contraindication to treatment. The case for treatment
The abundant evidence Unking the level of systolic and diastolic blood pressure with death from all causes, death from cardiovascular disease, incidence of stroke and incidence of coronary artery disease has been reviewed by Kannel (1976a). The stroke• Leicester, 20 October 1978.
116
Symposium on Hypertension in the Elderly
related risks are emphasized especially by Paul (1971) and by Kannel et al. (1970). The evidence Unking hypertension and myocardial infarction is suggestive rather than conclusive (Miall & Chinn 1974). Numerous well-controlled trials show that antihypertensive therapy reduces the risk of death (Breckenridge et al. 1970, Storm-Mathisen et al. 1973) and of stroke (Beevers et al. 1973a). These effects have been demonstrated in moderately and severely hypertensive men and women (Hamilton et al. 1964, Veterans Administration Co-operative Study Group 1967), in pregnant women (Leather et al. 1968) and in survivors of stroke (Carter 1970, Hypertensive-Stroke Co-operative Study Group 1974, Medical Research Council Working Party on Mild to Moderate Hypertension 1977). The reduction of the risk of stroke has been shown to be proportional to the effectiveness of treatment (Beevers et al. 19736). The effectiveness of treatment in reducing the risks of coronary heart disease was shown in one study (Berglund et al. 1978) but not in others (Breckenridge et al. 1970, M.R.C. 1977). Compliance with treatment was obtained in most patients in the special trials and sideeffects of treatment were infrequently prohibitive. However, compliance in the conditions of general practice in the United Kingdom, even in the younger age group, is much less satisfactory. TREATMENT OF HYPERTENSION IN PATIENTS AGED 65 AND OVER
The case for treating essential hypertension in patients aged 65 and over is less firmly based. Not only is the evidence conflicting and insufficient, but there are doubts about the case for treatment a priori. The argument a priori
Doubt has been cast on whether essential hypertension in those aged 65 and over is a disease; and if so whether it is the same disease as occurs in younger subjects. The argument runs that if hypertension is a lethal disease, then it might be expected that the average blood pressure of population groups will fall with increasing age, as a result of progressive elimination of those at highest risk (Smith 1957). In fact it has been known since before anti-hypertensive treatment was in wide use (Master et al. 1958, Society of Actuaries 1959, Anderson & Cowan 1959, 1972) that average blood pressure rises with age. Indeed in a group of healthy people aged 90 and over, half of the men and threequarters of the women had systolic blood pressure in excess of 160 mmHg (Danner et al. 1978). Does this mean, as suggested by Smith (1957), that for some people a high blood pressure in younger life confers survival value? Or does it mean that some people with a relatively low blood pressure in earlier life acquire a higher blood pressure as they grow older? In the former group antihypertensive therapy might be contra-indicated; while in the latter group, as Kannel (1976a) has shown, the rise in blood pressure is associated with increasing risk of damage and should presumably be treated. It is not always possible to distinguish, amongst elderly people with high blood pressure, those whose pressure has been rising; and to treat all hypertensives over the age of 65 without attempting to distinguish the two groups might mean exposing some to potential harm. THE RISKS OF HYPERTENSION IN THE ELDERLY
The evidence that high blood pressure in the elderly is harmful is fragmentary and conflicting. The evidence is very much stronger for patients aged 65-74 than it is for
Symposium on Hypertension in the Elderly
117
those aged 75 and over. The main source of our information on the former group is the Framingham Study; and, as has frequently been pointed out, there are genetic and environmental differences between the population of Framingham and that of the United Kingdom. The Framingham Study shows that for men and women aged 65-74 the risks of death from all causes and death from cardiovascular disease are twice as high for persons with systolic pressures of 160 and over as they are for those with systolic pressures of 130 and less (Kannel 1976a). There are also increased risks in those with high blood pressure in this age group of sudden death, myocardial infarction, congestive cardiac failure and coronary heart disease (Kannel 1976A). The Veterans Administration Study (1972) likewise found a high incidence of stroke, congestive cardiac failure and coronary artery disease in men aged 60 and over with diastolic blood pressure of 90114 mmHg. Data from the Rutherglen Clinic in Scotland showed that in men and women aged 70 and over there was an inverse relationship between the level of systolic blood pressure and survival, but this effect was weak. In women, but not in men, the diastolic blood pressure was directly related to survival; i.e. the higher the pressure the less was the risk to life (Anderson & Cowan 1976). In a London general practice the observed mortality rate amongst old people with elevated blood pressure was equal to or less than the rate predicted from life tables (Fry 1974). THE EFFECTIVENESS OF ANTI-HYPERTENSIVE TREATMENT IN THE ELDERLY
Despite the large number of elderly patients treated with antihypertensive drugs little acceptable evidence of effectiveness is yet available. In the Veterans Administration Cooperative Study (1972) of men aged 60 and over with diastolic blood pressure of 90-114 mmHg the incidence of strokes, congestive cardiac failure and coronary artery disease was halved in treated patients compared with controls. Waldek (1977) showed some improvement in a few elderly patients with left ventricular failure and retinopathy. Jackson et al. (1976), in an uncontrolled report, described serious symptoms occurring in elderly patients injudiciously treated with large and inappropriate doses of drug. A European Working Party on high blood pressure in the elderly has been established and has shown the feasibility of a large-scale clinical trial (Amery & de Schaepdryver 1973, Amery et al. 1977). This trial will supply some answers to our questions, but it will be some years before its results are available. TOLERANCE OF ELDERLY PATIENTS TO ANTIHYPERTENSIVE TREATMENT
Doctors who are reluctant to use antihypertensive therapy in elderly hypertensive patients are concerned about the effects of lowering blood pressure on cerebral blood flow. In normal people the autoregulatory mechanism maintains cerebral blood flow constant, despite fluctuations in blood pressure, until mean arterial pressure falls to about 60 mmHg (Taylor 1976). In hypertensive subjects the lower limit of autoregulation rises, and sharp falls in blood pressure may be associated with reduced cerebral perfusion (Strangaard et al. 1973). This mechanism is thought to be responsible for dizzy turns, light-headedness, falls, and even transient ischaemic attacks and strokes in elderly patients on antihypertensive therapy (Graham 1975, Jackson et al. 1976). Elderly
118
Symposium on Hypertension in the Elderly
hypertensive patients may be particularly sensitive to this mechanism, and even quite small reductions in blood pressure may significantly affect cerebral blood flow. Indeed small reductions in blood pressure induced by postural change have been shown to reduce cerebral blood flow in patients who developed symptoms of postural hypotension, but not in those who experienced a postural fall in blood pressure without symptoms (Wollner & McCarthy 1978). Studies of falls in old people living at home showed that those who fell took only slightly more anti-hypertensive drug compared with an agematched control group (Reinhold & Isaacs, unpublished). PRESCRIBING HABITS
The current prescribing scene, as reviewed by Hart (1975) and by Kannel (1976&), must cause dismay to those who would wish to see medical treatment practised rationally. The benefits of antihypertensive treatment in younger patients are very well attested: those in older patients are dubious. The risks of hypertension are greater in the male and less in the female. Nonetheless those most likely to be receiving antihypertensive medication are females over the age of 65 (Miall & Chinn 1974, Heller & Rose 1977). Older patients are more likely to have their blood pressure recorded than are younger ones (Hodes et al. 1975); and this may have something to do with the fact that older people are more likely to have older doctors. More than five million prescriptions for antihypertensive treatment are written each year in the United Kingdom (Hart 1977) and we really do not know how much good or how much harm they may be doing. It is perhaps reassuring that the amount of harm that they might do is limited by the fact that only a fraction of these drugs are actually consumed by the people for whom they are prescribed (Law & Chalmers 1976, Shaw & Opit 1976, Atkinson et al. 1977). GUIDANCE
The following guidance to prescribers is based partly on such evidence as there is, and partly on the author's prejudices. 1. Men aged 65-74 with systolic blood pressure in excess of 160 mmHg or diastolic blood pressure in excess of 90 mmHg, with or without a history of stroke or symptoms of hypertensive heart disease or progressive hypertensive retinal disease should receive antihypertensive therapy provided that: a. compliance with treatment is assured; b. blood pressure is lowered gently, preferably by a thiazide; c. disturbing side-effects do not occur. Treatment and compliance should be carefully monitored. If the patient survives to the age of 75 treatment should probably be discontinued then. 2. Women aged 65-74 with similar levels of blood pressure and with symptoms of hypertensive heart disease or retinal disease should receive treatment with similar provisos. Those without symptoms should not be treated, unless there is evidence of rapidly rising blood pressure. 3. For men and women aged 75 and over antihypertensive treatment should be prescribed only for the control of hypertensive heart failure; and for the very rare case
Symposium on Hypertension in the Elderly
119
of progressive hypertensive retinal damage. Symptomless patients should not be treated, no matter how high the level of the blood pressure. These guidelines will doubtless be revised as further facts become available. CONCLUSION
The prescribing of potent antihypertensive drugs to every elderly person with a high blood pressure will benefit a few, will harm many, and will be wholly irrelevant to the medical needs of most, especially of those in whom the high blood pressure is an incidental finding and is not the cause of the symptoms for which the patient has sought medical help. We still do not know in which elderly patients hypertension is a disease and in which it is, like old age itself, an achievement. Doctors are advised to curtail antihypertensive therapy in the elderly until much more is known about its effects. May I conclude by quoting Sir Francis Bacon: 'This subject of man's body is of all other things in nature most susceptible of remedy; but then that remedy is most susceptible of error. For the same subtlety of the subject doth cause large positivity and easy failing; and therefore the inquiry ought to be the more exact.' REFERENCES AMERY, A., BERTHAUX, P., BIRKENHAGER, W., BULPITT, C, CLEMENT, D., DE SCHAEPDRYVER, A., DOLLERY, C, ERROULD, H., FAGARD, R., FORETTE, F., HELLEMANS, J., KHO, T., LUNDJOHANSEN, P., MEURICE, J. & PIERQUIN, L. (1977) Antihypertensive therapy in elderly patients:
pilot trial of the European Working Party on High Blood Pressure in the Elderly. Gerontology 23, 426-37. AMERY, A. & DE SCHAEPDRYVER, A. (1973) Organisation of a double-blind multicentre trial on antihypertensive therapy in elderly patients. European Working Party on High Blood Pressure in Elderly. Clin. Sci. Mol. Med. 45, 71-3S. ANDERSON, W. F. & COWAN, N. R. (1959) Arterial pressure in healthy older people. Clin. Sci. 18, 103-18. ANDERSON, W. F. & COWAN, N. R. (1972) Arterial blood pressure in healthy older people. Gerontol. Clin., 14, 129-36. ANDERSON, W. F. & COWAN, N. R. (1976) Survival of healthy older people. Br. J. Prev. Soc. Med. 30, 231-2. ATKINSON, L., GIBSON, I. I. J. M. & ANDREWS, J. (1977) The difficulties of old people taking drugs. Age & Ageing 6, 144-50. BEEVERS, D. G., FAIRMAN, M. J., HAMILTON, M. & HARPUR, J. E. (1973a) The influence of antihypertensive treatment on the incidence of cerebrovascular disease. Postgrad. Med. J. 49, 905-7. BEEVERS, D. G., FAIRMAN, M. J., HAMILTON, M. & HARPUR, J. E. (19736) Antihypertensive treatment and the course of established cerebrovascular disease. Lancet i, 1407-9. BERGLUND, G., WILHELMSEN, L., SANNERSTEDT, R., HANSSON, L., ANDERSSON, O., SILVERTSSON, R., WEDEL, H. & WIKSTRAND, J. (1978) Coronary heart disease after treatment of hypertension.
Lancet i, 1-5. A., DOLLERY, C. T. & PARRY, E. N. O. (1970) Prognosis of treated hypertension, changes in life expectancy and causes of death between 1952 and 1967. Q.J. Med. 39, 411-29. CARTER, A. B. (1970) Hypertensive therapy in stroke survivors. Lancet i, 485-9. DANNER, S. A., DE BEAUMONT, M-J. & DUNNING, A. J. (1978) Cardiovascular health in the tenth decade. Br. Med. J. 2, 663. FRY, J. (1974) Natural history of hypertension: a case for selective non-treatment. Lancet ii, 431-3.
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D. I. (1975) Ischaemic brain damage of central perfusion type after treatment of severe hypertension. Br. Med. J. 4, 739. HAMILTON, M., THOMPSON, E. N. & WISNIEWSKI, T. K. M. (1964) The role of blood pressure control in preventing complications of hypertension. Lancet i, 235-8. HART, J. T. (1975) The management of high blood pressure in general practice. J. R. Coll. Gen. Pract. 25, 160-92. HART, J. T. (1977) Pressure on people. Br. Med.J. 1, 1462-3. HELLER, R. F. & ROSE, G. (1977) Current management of hypertension in general practice. Br. Med.J. 7,1442-4. HODES, C , ROGERS, P. A. & EVERITT, M. G. (1975) High blood pressure: detection and treatment by general practitioners. Br. Med. J. 2, 674-7. Hypertensive-Stroke Co-operative Study Group (1974) Effect of antihypertensive treatment on stroke recurrence. J. Am. Med. Assoc. 229, 409-18. JACKSON, G., PIERSCIANOWSKI, T. A., MAHON, W. & LONDON, J. (1976) Inappropriate antihypertensive therapy in the elderly. Lancet it, 1317-8. KANNEL, W. B., WOLF, P. A., VERTER, J. & MCNAMARA, P. M. (1970) Epidemiologic assessment of the role of blood pressure in stroke: the Framingham study. J. Am. Med. Assoc. 214, 301—10. KANNEL, W. B. (1976a) Blood pressure and the development of cardiovascular disease in the aged. pp. 143-75. In: Cardiology in Old Age Ed.: F. I. Caird, J. L. C. Dall & R. D. Kennedy. New York and London: Plenum Press. KANNEL, W. B. (19766) The Framingham Study. Br. Med. J. 2, 1255. LAW, R. & CHALMERS, C. (1976) Medicines and elderly people: a general practice survey. Br. Med.J. 1, 565-8. LEATHER, H. M., HUMPHREYS, D. M., BAKER, P. & CHADD, M. A. (1968) A controlled trial of antihypertensive agents in hypertension in pregnancy. Lancet ii, 488-90. MASTER, A. M., LASSER, R. P. & JAFFE, H. L. (1958) Blood pressure in white people over 65 years of age. Am. Intern. Med. 48, 284-99. Medical Research Council Working Party on Mild to Moderate Hypertension (1977) Randomised controlled trial of treatment for mild hypertension: design and pilot trial. Br. Med. J. 1, 1437-40. MIALL, W. E. & CHFNN, S. (1974) Screening for hypertension: some epidemiological observations. Br. Med. J. 3, 595-600. PAUL, O. (1971) Risks of mild hypertension: a ten-year report. Br. Health J. (Suppl.) 33, 116-21. SHAW, S. M. & OPIT, L. J. (1976) Need for supervision in the elderly receiving long-term prescribed medication. Br. Med. J. 1, 505-7. SMITH, J. M. (1957) Genetic variations in ageing, pp. 115-122. In: The Biology of Ageing Ed.: W. B. Yapp & G. H. Bourne. London: Institute of Biology. Society of Actuaries (1959) Build and Blood Pressure Study Vol. 1. Chicago: Society of Actuaries. STORM-MATHISEN, H., LOKEN, H. & RIAN, V. (1973) Complications in treated hypertension. Clin. Sci. Mol. Med. 45, 205-8S. STRANDGAARD, S., OLESEN, J., SKINHOJ, E. & LASSEN, V. A. (1973) Autoregulation of brain circulation in severe arterial hypertension. Br. Med. J. 1, 507-10. TAYLOR, D. E. M. (1976) Factors affecting cerebral blood flow. pp. 128-41. In: Stroke Ed.: F. J. Gillingham, C. Mawdsley & A. E. Williams. Edinburgh: Churchill Livingstone. Veterans Administration Co-operative Study Group on Antihypertensive Agents (1967). Effect of treatment on morbidity in hypertension: results in patients with diastolic blood pressures averaging 115 through 129 mmHgJ. Am. Med. Assoc. 202, 1028-34. Veterans Administration Co-operative Study Group on Antihypertensive Agents (1972) Effects of treatment on morbidity in hypertension: III. Influence of age, diastolic pressure, and prior cardiovascular disease: further analysis of side effects. Circulation 45, 991-1004. WALDEK, S. (1977) Hypertension in the elderly. Lancet i, 1055. WOLLNER, L. & MCCARTHY, S. T. (1978) Failure of autoregulation as a cause of brain dysfunction in the elderly. Paper read at meeting of British Geriatrics Society, London. GRAHAM,
