Preventing Coronary Heart Disease

Prospects, Policies, and Politics

Michael Calnan

• Publisher: Routledge
• Year: 2002
• Print ISBN: 9780415044905
• eBook ISBN: 9781134949373
• Edition: 1
• Topic: Medicine
• Subtopic: Health Care Delivery

Coronary Heart Disease is the major cause of death in the UK, being responsible for thirty-one percent of male deaths and for twenty-four percent of female deaths in 1987 in England and Wales. Preventing Coronary Heart Disease examines these statistics and focuses specifically on policies for its prevention by the Government, general practitioners, and concerned groups. Michael Calnan looks at the feasibility and effectiveness of these health policies and the obstacles in the way of their adoption. Drawing mainly on the discipline of politics, sociology, and epidemiology the author begins by examining the epidemiological case for prevention, and then analyses what the UK Government is doing and can do. The Government's policy is based on the role of primary care in prevention and the author discusses how this can be taken on board by GPs, concerned groups and the general public. Coronary heart disease is of major concern to all those working in health and related industries, as well as to individuals. This book is the first study of the policies of prevention of the disease and will be invaluable reading for students of health studies, and social policy as well as professionals working in health care.

1
Prospects for prevention

The broad aim of this book is to examine policies for the prevention of coronary heart disease. More specifically, the book focuses on recent policy proposals which highlight the central role that general practitioners and their primary health care teams should play in the prevention of coronary heart disease. The following chapters focus on coronary heart disease prevention policies in general and how policies emphasising the role of general practitioners emerged. This is followed by a detailed examination of these policies and the assumptions that underlie them. Then, the empirical evidence is analysed particularly focusing on the feasibility of the proposals, the views of the general practitioners themselves and the barriers to involvement. The final chapter focuses on lay health beliefs and health practices and the factors which shape them. From the general practitioners’ point of view an understanding of the lay perspective is crucial if their interventions are to be effective.

In this introductory chapter, however, the emphasis will be placed on setting the scene. Thus, this chapter will begin by providing some background information about the nature of CHD (coronary heart disease), the size of the problem and the prospects for prevention.

What is CHD?

Coronary heart disease is a condition where the heart muscle (myocardium) receives insufficient oxygen because the coronary arteries fail to maintain a sufficient supply of blood. (For full details see Open University (1985a).) There are two reasons why arteries cannot maintain an adequate supply of blood. One of these is coronary artery spasm (Bray and Ward, 1986) although this is usually a common accompaniment of coronary obstruction which is the major reason. Coronary obstruction develops when the arteries become more rigid and narrow due to the accumulation of fatty deposits (plaque). These fatty deposits are made up mainly of cholesterol and fibrin and when these deposits are prevalent the condition is called atherosclerosis (Open University, 1985b).

There is still some uncertainty about how these fatty deposits arise. Narrowing of the arteries is, in some respects, a natural product of ageing. However, there are more specific theories and two are popular at the moment (Open University, 1985b). The first suggests that fats move into the arterial wall from the blood where they help produce large amounts of scar tissue. The second suggests that blood clots that form the arterial wall are integrated into the wall where they degenerate into the fat and fibrin found in the deposits. The plaques themselves become the focal point for the formation of more blood clots which can sometimes completely block off an artery. In addition, a piece of plaque may break off and move down the artery until it blocks it. However, the main effect of atherosclerosis is to cause narrowing of the arteries and the severity of the condition is dependent on the location of these deposits.

How then does CHD affect people? It tends to affect people in three main ways by producing (Open University, 1985b):

• (i) angina (chest pain) which can cause considerable debilitation. This occurs when cardiac activity is increased such as when an individual is exercising and the partial blockage in the arteries does not allow sufficient oxygen to reach the heart. This can cause cramp in the heart muscle which can be felt as pain in the chest or arm. The pain recedes once the exercise is stopped and the heart rate returns to normal.
• (ii) myocardial infarction (heart attack) is where a part of the heart muscle is permanently damaged. This is where the coronary artery becomes completely blocked off and the deprivation of blood will lead to death of cells in the heart muscle. The effect of a dead patch of muscle in the heart depends on its extent and location. Sometimes it can lead to death although usually the person recovers. The pain of myocardial infarction is of a similar type to angina but it is usually more prolonged and severe and tends to be of quite sudden onset.
• (iii) sudden death which is the result of the heart muscle suddenly stopping. This is usually due to thrombosis (blood clot) on a plaque.

Size of the Problem of CHD

Coronary heart disease was the major cause of death in England and Wales in 1987 for males and one of the major causes for females (OPCS, 1988). Thirty-one per cent of the total of 280,177 male deaths in that year and 24 per cent of the total of 286,817 female deaths were due to CHD. CHD also appears to be a major cause of premature death particularly in men. For example, CHD was the major cause of male death (34 per cent) in the age group 35–54 and in the age group 55–64 where it made up 39 per cent of all male deaths. For women the pattern was slightly different in that it was only the major cause of death in the age group 55 and above (OPCS, 1988).

There are also social class variations in the rates of mortality from CHD. For example, evidence from the Whitehall study (Marmot et al., 1984) of 17,350 civil servants showed that compared with the highest grade (administrators), men in the lowest grade had 3 times the mortality rate from CHD. More recent figures for mortality in Great Britain also illustrate these variations by social class. For example, in between 1979 and 1983 for men aged 20 to 64 the rate of deaths from CHD per 1,000 population was 1.2 in professional occupations compared with 2.2 in semi-skilled occupations and 3.5 in skilled occupations (OPCS, 1986a). A similar pattern was found for women in that during the same period the proportional mortality rates from diseases of the circulatory system for women teachers was 76 compared with 111 for women cleaners and 114 for female assembly workers (OPCS, 1986a). Also, evidence from the British Regional Heart Study (Pocock et al., 1987) showed that the prevalence rates of CHD at screening were higher in manual workers and the attack rate of major CHD events during follow-up was 44 per cent higher in manual workers.

The estimates for the incidence of CHD by age and sex for England and Wales, 1981–82, (Coronary Prevention Group (CPG), 1989) clearly illustrate how the incidence rises markedly in middle age for both men and women. For example for men aged 25–44 the incidence of myocardial infarction was 0.8 compared with 7.4 in the age group 45–64 and 12.8 in the age group 65–74. For women a similar trend was found in that the incidence of myocardial infarction was from 0.2 in the age groups 25–44, to 2.5 in the age groups 45–64 to 6.8 in the age groups 65–74. Data on incidence and prevalence of CHD for the male population rather than those who consult a general practitioner are available from the British Regional Heart Study (Shaper et al., 1984a) which is a prospective study primarily investigating the geographical variations in the incidence of CHD. The study includes 7,765 men aged 40–59 years who were randomly selected from the age–sex registers of group general practices in 24 towns in England, Wales and Scotland. The prevalence of CHD was determined by an administered questionnaire and electrocardiography (ECG) to the 7,765 men in the sample. The data were collected at the beginning of the study between 1978 and 1980.

Data collected through the questionnaire showed eight per cent to have angina, nine per cent to have possible myocardial infarction and 14 per cent to have some kind of CHD which was angina or possible myocardial infarction or both. Evidence from the ECG showed around three per cent with major abnormalities and another 11 per cent with other abnormalities. There was some overlap between the reports in the questionnaire and the evidence from the ECG although over half of those with possible myocardial infarction combined with angina had no evidence on the ECG of CHD, and half of those with definite myocardial infarction on the ECG had no history of chest pain at any time. Overall, around one-quarter of the sample had some evidence of CHD on a questionnaire on chest pain or on ECG. This group was divided up into four per cent where there was evidence from the ECG and the questionnaire, ten per cent from the questionnaire only, and 11 per cent from the ECG only.

This evidence from the British Regional Heart Study suggests that CHD is common in middle-aged men in Great Britain. Further analysis of data from this study (Shaper et al., 1984b) suggests that although CHD is common amongst this age group there is a low level of awareness amongst both doctors and patients. For example, only one-third of the men with possible myocardial infarction and half of those with a definite myocardial infarction on ECG could recall a diagnosis of CHD. Even in severe angina 40 per cent could not recall being told that they had heart disease. Overall, only one in five of those regarded as having CHD was able to recall such a diagnosis having been made by a doctor, and these were likely to be those most severely affected. This high level of unawareness amongst men about their own problems combined with similar unawareness by doctors of the true prevalence of disease and caution over applying the diagnostic label, is, according to the authors, one of the major reasons behind the lack of concerted action in this country to control CHD.

Trends in National and International Mortality

High rates of mortality from CHD are seen as a specific characteristic of the twentieth century and a product of the social and economic changes brought about by industrial development. However, it is difficult, given the lack of detailed historical evidence (Bartley, 1985) to know how far the increase in prevalence is a real one and how far it is an artefact of changes in doctors’ recognition or discovery of the disease. This debate remains unresolved although it does not so much apply to more recent changes in mortality where data are more reliable.

Deaths from CHD rose slowly both for men and women during the 1960s, and then in 1978 it started a steady decline up until 1987. Thus, in 1968 the death rates for men aged 35–74 was 583, by 1978 it had reached 615 and had decreased to 512 by 1987. This decline appears to have occurred in all age groups. The recent steady decline in mortality appears to be more marked for men than women. In 1968 the death rates for women aged 35–74 was 201, it rose to 207 by 1978 but had declined to 186 by 1987.

Internationally, the mortality rate for CHD (Shaper, 1986) in England and Wales has been described as being at a ‘moderate’ level. For example, in 1986 the death from CHD for men in England and Wales aged 35–74 was 439 compared with 701 in Northern Ireland, 623 in Scotland, 617 in Finland, 592 in Czechoslovakia, 590 in Ireland and 442 in Sweden. However, these figures are slightly misleading in that in Japan the death rate for that year and that age group was 67, it was 163 in France, 351 in Germany, 375 in the USA and 305 in Australia. Thus, England and Wales, while not at the top, are still quite high up the league table for deaths from CHD.

The recent steady decline in CHD mortality rates in England and Wales stands in marked contrast to countries like the United States and Finland, which between 1968 and 1986 have experienced a significant decline in mortality rates. However, it must be remembered that these two countries both had very high mortality rates originally, e.g. in 1968 both had male death rates from CHD of over 800. Perhaps the most dramatic decline has occurred in the United States. For example, during the period immediately after the war the USA experienced a progressive increase in mortality from CHD (Shaper, 1986). Since then, however, there has been a marked reversal in this upward trend (Epstein, 1984). Between 1968 and 1978 the mortality from CHD in terms of age-adjusted rates declined by 25 per cent for white men, 27 per cent for white women, 24 per cent for non-white men and 38 per cent for non-white women. The declines in each of these four groups have been markedly greater in younger rather than older age groups. In 1968 the CHD mortality rate in England and Wales was almost three-quarters of that in the USA. However, by 1985 the position had almost reversed and the mortality rates in the USA were around three-quarters of those in the UK.

This marked decline in the United States is claimed by some (Epstein, 1984) to be due in large part to the successful efforts of primary prevention, attributable in turn to improved eating habits, better control of blood pressure and a reduction in smoking. However, it is also accepted (Epstein, 1984) that another part of the decline will probably be explained by an improvement in prognosis and treatment. One explanation which has been neglected is what Pearson (1988) refers to as point source exposure and the decline in rates may involve the removal of this exposure. These exposures could be illnesses or social events such as depression or war.

In contrast, other countries’ CHD mortality rates during the period 1968–78 (Pisa and Uemura, 1982; Thom et al., 1985) have increased. The most notable increases have been in the Eastern European countries such as Poland, Yugoslavia and Rumania which have witnessed at least a 45 per cent increase during this period. Shaper (1986) suggests that increases reflect the increasing consumer demands for a ‘Western diet’ combined with an already high prevalence of obesity, hypertension and cigarette smoking.

In summary, CHD mortality rates in England and Wales are by current international standards at moderate levels whereas in Scotland and Northern Ireland they are high. Both countries have only very recently experienced a decline in mortality although this is only slight compared with the dramatic declines found in countries such as the USA and Finland.

There are also marked regional variations in death rates from CHD within England and Wales. For example, variations in rates in 1987 for men by Regional Health Authority (OPCS, 1988) suggest that the black spots for CHD are in Wales (422 per 100,000 pop.) and the North (446), particularly the North West region (441). Lower rates tend to be found in the Southern regions, particularly around the home counties (354 in the South East), in East Anglia (350) and in the West Country (359).

Economic and Social Costs

Elkan (1988) and Wells (1987) have estimated the economic costs imposed by CHD in England and Wales. Costs are divided into those which are the direct result of medical care and the indirect costs such as those stemming from absence due to sickness.

CHD in England and Wales in 1985 is estimated to have cost the National Health Service £389.9 million (Wells, 1987). The treatment absorbed one pound in every fifty spent by the NHS. The major part of the medical care costs are taken up with hospital inpatient care (£204 million) and primary care (£176.6 million). The remainder went on outpatient care (£9.3 million). Elkan (1988) in a similar analysis estimated the total direct costs of the impact of CHD as £431 million.

Wells (1982) also considered future trends in medical care costs and argued that because no dramatic changes in CHD mortality rates are expected in England and Wales at least in the short-term the shifts in the economic burden of CHD will depend upon the adoption of new forms of treatments. For example, it is estimated (Wells, 1982) that an increase in the operation rate from coronary bypass surgery to half the rate prevailing in the USA would cost an extra £26 million. This cost might be offset by savings on social security payments and increased tax contributions. For example, Wasfie and Brown (1981) have calculated that on average NHS costs per case of CABG are recovered within six years ten months as a result of reduced social security payments and the restoration of taxation contributions.

The indirect costs from CHD are more difficult to measure and to estimate. Certainly, the social and psychological consequences of CHD both for sufferers and their relatives are high. Levels of sickness absence are more easy to quantify and Elkan (1988) estimates that 34 million working days are lost per year because of CHD resulting in sickness benefit payments totalling £215 million. This excludes other social benefits that the sick may also be receiving. In addition, Wells (see Elkan, 1988) assessed the value of foregone production, due to absence from work, at £1,431 million at 1986 incomes. He also assessed the loss of production due to CHD deaths in 1985 at £2,412 million.

Controlling Coronary Heart Disease: Treatment

The evidence presented so far clearly shows that CHD is a major health problem in Great Britain. But what are the best ways of controlling it? This book focuses primarily on prevention although in this section treatment will be briefly considered.

The treatment of CHD is claimed (Open University, 1985a) to have three main objectives which are:

• (i) The prevention of death immediately after a myocardial infarction
• (ii) Prevention of disablement by severe angina
• (iii) Prevention of further myocardial infarctions

It is clear from the above that these different objectives of treatment do not represent a ‘cure’ for CHD but are ways of relieving symptoms, improving quality of life and increasing survival.

Intensive care treatment (drugs and life-support systems) is used to prevent death immediately after a myocardial infarction although there is some doubt about its effectiveness. Rose (1975) suggested that only five per cent of patients benefit from being admitted to intensive care units as opposed to being cared for at home. There is the additional problem that most deaths occur within the first two hours after a myocardial infarction before it is usually possible to get someone into hospital. For example, it might be predicted that of 100 patients who had a heart attack (see Figure 1.1) 45 would die within a year and 25 of these deaths would be immediate.

The improvements in the treatment of CHD have mainly occurred in relation to the management of angina. Diagnosis of angina and decisions about the most appropriate form of treatment have been assisted by the development of a range of investigative techniques such as exercise testing and invasive investigations such as coronary angiography (Bray and Ward, 1986). One common method of treating angina is through drug therapy where the aim is to increase the blood flow to the heart or to decrease the work of the heart. There are three groups of drug which are currently used, sometimes in combination, for healing angina and they are (1) nitrates, (2) beta-blockers, (3) calcium antagonists (Bray and Ward, 1986). Surgery is the alternative method of treating angina. The form of treatment which has been the recent focus of a lot of interest and debate is...

Table of contents

• Cover
• Title
• Copyright
• Contents
• List of figures and tables
• Acknowledgements
• 1 Prospects for prevention
• 2 Policies for the prevention of CHD: the approach of government
• 3 General practice and prevention: policy analysis
• 4 The perspective of the general practitioner
• 5 Explaining patterns of health-related behaviour
• 6 A conclusion
• References
• Name index
• Subject index