Epidemiology of coronary heart disease

Incidence and prevalence¹

Healthcare costs relating to cardiovascular diseases (CVD) are estimated at £9 billion each year. CVD's cost to the UK economy (including premature death, disability and informal costs) is estimated to be £19 billion each year.

There are 2.3 million people in the UK living with CHD (about 1.5 million men and 830,000 women).

It is estimated that around 1.4 million people alive in the UK today have survived a myocardial infarction (about 1 million men and 380,000 women).

Mortality rates

• Coronary heart disease (CHD) is the most common cause of death (and premature death) in the UK.

• Coronary heart disease (CHD) is the one of the UK’s leading causes of death and the most common cause of premature death. CHD is responsible for about 66,000 deaths in the UK each year.

• In 2019, CHD caused 13% of male and 8% of female deaths. It was the leading cause of death worldwide in 2019. In the UK, one in eight men and one in 14 women die from coronary heart disease.

• About 25,000 people under the age of 75 in the UK die from CHD each year.

• CHD kills more than twice as many women in the UK as breast cancer, and kills more women prematurely (before their 75th birthday).

• CHD death rates are highest in Scotland and the north of England.

• In the UK as many as 100,000 hospital admissions each year are due to myocardial infarctions.

• In the 1960s more than 7 out of 10 myocardial infarctions in the UK were fatal. Today at least 7 out of 10 people survive.

• Although mortality from CHD is falling, morbidity appears to be rising.

• Despite the decline in death rates from cardiovascular disease (CVD) in the UK, rates are still relatively high compared to other Western European countries.² In Western Europe, only Ireland, Germany, Sweden and Luxembourg had a higher death rate than the UK in the same year.

Morbidity rates¹

• The British Heart Foundation estimates that in 2016, 2.3 million people in the UK were living with a diagnosis of coronary heart disease and around 1 million people had survived a myocardial infarction.

• Data from the UK Clinical Practice Research Datalink in 2012 estimated that 3.05% of men and 1.79% of women experience angina, with incidence rising with increasing age in both sexes.³

Coronary heart disease causes (aetiology)¹

The aetiology of CHD is multifactorial. It is the result of interaction between genetic, lifestyle and environmental factors. Poor diet and other lifestyle factors are estimated to account for about one-third of all deaths from CVD in England.⁴

Age

CHD increases with age.¹

Gender

• Traditionally, CHD has been considered a disease of men. However, CHD is the leading cause of death both in men and women.⁵

• It is responsible for a third of all deaths in women worldwide and half of all deaths in women over the age of 50 years in developing countries.⁶

Social deprivation

• In England and Wales there is a positive correlation between deaths from circulatory diseases and levels of deprivation.⁷

• There is a marked difference in prevalence of CHD between and within communities.

• Men and women living in the West of Scotland are nearly six times more likely to die prematurely from CHD than men and women living in the South West of England.

• Within London, people living in Tower Hamlets have a three times increased risk of dying prematurely from CHD compared with those in Kensington and Chelsea.

• The difference in CHD rates in different socio-economic groups is related to many factors, including diet, smoking, exercise, and alcohol.

Smoking

• Mortality from CHD is 60% higher in smokers.⁸

• Regular exposure to passive smoking increases CHD risk by up to 25-30%.⁹

• World Health Organization (WHO) research estimates that over 20% of CVD is due to smoking.¹⁰

Poor nutrition

There are national, regional, socio-economic and ethnic differences in nutrition.

• A WHO report in 2003 stated that a diet high in fat (particularly saturated fat), sodium and sugar and low in complex carbohydrates, fruit and vegetables increases the risk of CVD.¹¹

• It has been recommended that the percentage food energy derived from fat should be 35%, with 11% from saturated fat. However, there is currently some debate regarding the validity of current advice regarding a low-fat diet.

• Trans fatty acids reduce high-density lipoprotein (HDL) and increase low-density lipoprotein (LDL) cholesterol and can increase CHD risk. A meta-analysis showed that a 2% increase in the energy intake from trans fatty acids increased CHD incidence by 23%.¹²

• Eating oily fish rich in omega-3 fatty acids has been shown to reduce CHD mortality.¹³

• Increased intake in dietary fibre also appears to reduce risk.

• A healthy diet is essential, irrespective of the individual risk of CVD.¹⁴

Infrequent exercise

• Physical activity reduces the risk of CHD.¹⁵

• The 2002 World Health Report estimated that over 20% of CHD in developed countries was due to physical inactivity.

• Recommended physical activity levels are 30 minutes of moderate physical activity on five or more days per week.

• Over one third of UK adults are estimated to be inactive (exercising for less than one occasion of 30 minutes per week).

Alcohol

• 1 to 2 units of alcohol per day reduce the risk of CHD. Alcohol increases HDL cholesterol and reduces thrombotic risk. Higher levels of consumption increase risks from other causes.

• The World Health Report in 2002 estimated that 2% of CHD in men in developed countries is due to excessive alcohol consumption.

• Men should drink no more than 3 to 4 units on any one day and women no more than 2 to 3 units.

Psychosocial wellbeing

• Work stress, lack of social support, depression, anxiety and personality (particularly hostility) can all increase CHD risk.

Blood pressure

• For adults aged 40 to 69 years, each 20 mm Hg rise in usual systolic blood pressure or 10 mm Hg rise in diastolic blood pressure doubles the risk of death from CHD.

• The INTERHEART study showed that 22% of myocardial infarctions in Western Europe were due to a history of high blood pressure and those with hypertension had almost twice the risk of a myocardial infarction.¹⁶

Cholesterol

• CHD risk is related to cholesterol levels.

• The INTERHEART study suggested that 45% of myocardial infarctions in Western Europe are due to abnormal blood lipids.¹⁶

• People with low levels of HDL cholesterol have an increased risk of CHD and a worse prognosis after a myocardial infarction.

• In the UK, it is suggested that the target cholesterol is <4 mmol/L for people with diabetes or established CVD or for people at high risk of developing CVD. People with HDL cholesterol <1 mmol/L should also be considered for treatment.

Overweight and obesity

• Obesity is an independent risk factor for CHD. It is also a risk factor for hypertension, hyperlipidaemia, diabetes and impaired glucose tolerance.

• Central or abdominal obesity is most significant. Those with central obesity have over twice the risk of myocardial infarction.¹⁶

Diabetes

• Men with type 2 diabetes have a 2 to 4 times greater annual risk of CHD; women have a 3 to 5 times greater risk.

• Around 6% of men and 5% of women in England have diagnosed diabetes. The prevalence is increasing.

Ethnicity

• South Asian people living in the UK (people from India, Pakistan, Bangladesh and Sri Lanka) have a higher premature death rate from CHD (46% higher for men; 51% higher for women).¹

• Hypotheses for this include migration, disadvantaged socio-economic status, 'proatherogenic diet', lack of exercise, high levels of homocysteine and lipoprotein(a) (Lp(a)), endothelial dysfunction and enhanced plaque and systemic inflammation.¹⁷

• The premature death rate from CHD in West African people and people from the Caribbean is much lower (half the rate compared with the general population for men and two thirds of the rate for women).

Family history¹⁸

• First-degree relatives of patients with premature myocardial infarction have double the risk themselves.

• Premature CHD is that before age 55 years in men and 60 years in women.

• More than one third of admissions for premature myocardial infarction could be prevented by screening and treating first-degree relatives.

• Genetic predisposition and shared lifestyle are likely to contribute.

• Several regions of the human genome have been shown to be associated with either CHD or hypertension.

Serum homocysteine

• It has been considered that elevated levels of homocysteine are an independent risk factor for CHD, likely due to oxidative damage to the endothelium, platelet activation and thrombus formation.

• However, there is no evidence to suggest that homocysteine-lowering interventions in the form of supplements of vitamins B6, B9 or B12 given alone or in combination should be used for preventing cardiovascular events.¹⁹

Economic cost¹

Healthcare costs relating to cardiovascular diseases (CVD) are estimated at £9 billion each year. CVD's cost to the UK economy (including premature death, disability and informal costs) is estimated to be £19 billion each year.