Coronary heart disease

What is coronary heart disease?

Coronary heart disease (CHD), also known as ischaemic heart disease, is the most common cardiovascular disease. There are 2 main clinical forms—heart attack and angina.

Heart attack—or acute myocardial infarction (AMI)—is a life-threatening event that occurs when a blood vessel supplying the heart is suddenly blocked, threatening to damage the heart muscle and its functions. STEMI (ST segment elevation myocardial infarction) is the most serious type of heart attack. It is almost always caused by a complete blockage of a major coronary artery, leading to a long interruption of blood supply. NSTEMI (Non-ST segment elevation myocardial infarction) is characterised by a partially blocked artery, which severely reduces blood flow.

Angina is chest pain caused by reduced blood flow to the heart. With stable angina, periodic episodes of chest pain occur when the heart has a temporary deficiency in blood supply. Unstable angina is an accelerating pattern of chest discomfort, and is the more dangerous form due to a changing severity in partial coronary artery blockages. It is treated in a similar manner to heart attack.

Both heart attack and unstable angina are sudden, severe life-threatening events. They are part of a continuum of acute coronary heart diseases, and are together described as acute coronary syndrome (ACS).

How many Australians have coronary heart disease?

An estimated 580,000 Australians aged 18 and over (3.1% of the adult population) had CHD at some time in their lives, based on self-reported data from the ABS 2017–18 National Health Survey (AIHW analysis of ABS 2019).

Of those with CHD, 227,000 had experienced angina while 430,000 had a heart attack or another form of CHD, noting that a person may report more than 1 disease.

Age and sex

  • After adjusting for age, a higher percentage of men (3.8%) than women (1.9%) were estimated to have CHD in 2017–18.
  • CHD occurred more commonly in older age groups, increasing from 1.1% in those aged 45–54 to 14% among those aged 75 and over.
  • At age 75 and over, there is a marked difference between men (21%) and women (8.1%) reporting having CHD (Figure 1).

Figure 1: Prevalence of self-reported coronary heart disease among persons aged 18 and over, by age and sex, 2017–18

The bar chart shows the prevalence of self-reported coronary heart disease by age group in 2017–18. Rates were highest among men and women aged 75 and over (21% and 8.1%).

Variation among population groups

Aboriginal and Torres Strait Islander people

  • An estimated 27,400 Aboriginal and Torres Strait Islander adults had CHD, based on self-reported data from the ABS 2018–19 Australian Aboriginal and Torres Strait Islander Health Survey (AIHW analysis of ABS 2019b).
  • After adjusting for age, the rate of CHD among Indigenous adults was more than twice that of non-Indigenous adults (7.4% and 2.7%).
  • Indigenous men were 2.5 times as likely to report having CHD as non-Indigenous men (9.1% and 3.6%), and Indigenous women 3.3 times as likely as non-Indigenous women (5.9% and 1.8%) (Figure 2).

Socioeconomic group

  • In 2017–18, the percentage of adults who reported having CHD was higher among those living in the most socioeconomically disadvantaged areas compared with those in the least disadvantaged areas (age-standardised rates of 3.2% and 2.0%) (Figure 2).
  • Rates were significantly higher for men than women across most socioeconomic groups.

Remoteness area

In 2017–18, the prevalence of CHD among adults, based on self-reported data, did not vary significantly by remoteness area (age-standardised rates of 2.7% in Major cities, 3.3% in Inner regional, 2.4% in Outer regional and remote) (Figure 2).

Figure 2: Prevalence of self-reported coronary heart disease, among persons aged 18 and over, by population group and sex, 2017–18

The horizontal bar chart shows that the prevalence of self-reported coronary heart disease in 2017–18 was higher among Indigenous Australians and people living in socioeconomically disadvantaged areas, but did not vary significantly by remoteness areas.


Acute coronary events

There are no national data sources on the number of new cases (incidence) of CHD each year. However, a related measure can be used as an estimate—the number of acute coronary events (including heart attack and unstable angina)—developed by the AIHW using unlinked hospital and deaths data (AIHW 2014).

In 2018, there were an estimated 58,700 acute coronary events among people aged 25 and over—equivalent to around 161 events every day. Around 13% of these events (7,700 cases) were fatal.

Age and sex

In 2018, an estimated two-thirds (65%) of acute coronary events among persons aged 25 and over occurred in men.

Rates of acute coronary events:

  • were more than twice as high in men than women (age-standardised rates of 424 and 190 per 100,000 population)
  • increased with age, with the rate among the 85 and over age group (2,100 per 100,000 population) more than 3 times the rate of the 65–74 age group (639 per 100,000 population) and 5 times the rate for the 55–64 year old age group (408 per 100,000 population) (Figure 3).

Figure 3: Acute coronary events among persons aged 25 and over, by age and sex, 2018

The bar chart shows rates of acute coronary events by age group in 2017–18. These were highest among men and women aged 85 and over (2,500 and 1,800 per 100,000 population).

Trends

The age-standardised rate of acute coronary events fell by more than half (55%) between 2001 and 2018 (675 to 302 per 100,000 population). The decline was slightly higher for women (59%) than men (54%) (Figure 4).

The decline in rates of acute coronary events has been attributed to a number of factors, including improvements in medical and surgical treatment, and the increased use of antithrombotic drugs as well as drugs to lower blood pressure and cholesterol. Reductions in risk factor levels—including tobacco smoking, high blood cholesterol and high blood pressure—have also contributed to these declines (Taylor et al. 2006).

Figure 4: Acute coronary events among persons aged 25 and over, by sex, 2001–2018

The line chart shows declines in age-standardised rates of acute coronary events between 2001 and 2018, from 912 to 424 per 100,000 population for men aged 25 and over, and from 462 to 190 for women.

Aboriginal and Torres Strait Islander people

Indigenous Australians have considerably higher rates of acute coronary events than non-Indigenous Australians—2.6 times as high in 2018 (age-standardised rates of 757 and 293 per 100,000 population).

The rate of acute coronary events among younger Indigenous people is many times that of younger non-Indigenous people (AIHW 2015).


Hospitalisations

In 2018–19 there were 161,000 hospitalisations where CHD was recorded as the principal diagnosis, equivalent to 1.4% of all hospitalisations, and 27% of all CVD hospitalisations in Australia.

Of these, angina accounted for 23% (37,600 hospitalisations) and acute myocardial infarction (AMI) for 36% (57,300 hospitalisations).

Age and sex

In 2018–19, CHD hospitalisation rates as the principal diagnosis:

  • were overall 2.5 times as high for males as females (784 and 313 per 100,000 population) after adjusting for age. Age-specific rates were higher among males than females across all age groups (Figure 5)
  • increased to age 75–84, with two-thirds (65%) of CHD hospitalisations occurring in those aged 65 and over. CHD hospitalisation rates for males were highest in the 75–84 age group (4,500 per 100,000 population) and for females in the 85 and over age group (2,300 per 100,000 population).

Figure 5: Coronary heart disease hospitalisation rates, principal diagnosis, by age and sex, 2018–19

The bar chart shows coronary heart disease hospitalisation rates by age group in 2018–19. Rates were highest among males aged 75–84 (4,520 per 100,000 population) and females aged 85 and over (2,346 per 100,000 population).

Trends

After adjusting for different population age structures over time, there was a 35% reduction in the rate of hospitalisations with a principal diagnosis of CHD between 2000–01 and 2018–19, from 833 to 539 per 100,000 population.

The number of CHD hospitalisations increased by 7.6% for males and fell by 9.9% for females, while the rate of CHD hospitalisation fell by 41% for females (from 532 to 313 per 100,000 population) and 33% for males (from 1,165 to 784) (Figure 6).

Figure 6: Coronary heart disease hospitalisation rates, principal diagnosis, by sex, 2000–01 to 2018–19

The line chart shows the decline in age-standardised rates of coronary heart disease hospitalisations between 2000–01 and 2018–19, from 1,165 to 784 per 100,000 population for males, and from 532 to 313 for females.

Variation among population groups

Aboriginal and Torres Strait Islander people

In 2018–19, there were around 5,400 hospitalisations with a principal diagnosis of CHD among Aboriginal and Torres Strait Islander people.

After adjusting for differences in the age structure of the populations:

  • the rate among Indigenous Australians was 2.1 times as high as the non-Indigenous rate (1,103 and 516 per 100,000 population)
  • the disparity between Indigenous and non-Indigenous Australians was greater for females than males—3.1 times as high for females (920 and 295 per 100,000 population) and 1.7 times as high for males (1,312 and 756 per 100,000 population) (Figure 7).

Socioeconomic group

In 2018–19, CHD hospitalisation rates were almost 30% higher for people living in the lowest socioeconomic areas compared with those in the highest socioeconomic areas—age-standardised rates of 609 and 475 per 100,000 population.

The disparity was greater for females (382 and 246 per 100,000 population) than males (853 and 727 per 100,000 population) (Figure 7).

Remoteness area

In 2018–19, CHD hospitalisation rates were around 45% higher among those living in Remote and very remote areas compared with those in Major cities (age-standardised rates of 742 and 510 hospitalisations per 100,000 population).

This largely reflects disparities in female rates, which were twice as high in Remote and very remote areas as in Major cities (566 and 287 per 100,000 population)—while males rates were 1.2 times as high (895 and 759 per 100,000 population) (Figure 7).

Figure 7: Coronary heart disease hospitalisation rates, principal diagnosis, by population group and sex, 2018–19

The horizontal bar chart shows that male and female coronary heart disease hospitalisation rates in 2018–19 were higher among Indigenous Australians, people living in the lowest socioeconomic areas, and people living in remote and very remote areas.


Deaths

In 2019, coronary heart disease (CHD) was the underlying cause of 17,700 deaths (11% of all deaths and 42% of all CVD deaths).

Almost 2 in 5 (39%) CHD deaths in 2019 (7,000) resulted from acute myocardial infarction (AMI, or heart attack).

Age and sex

In 2019:

  • CHD death rates were twice as high for males as for females (age-standardised rates of 73 and 37 per 100,000 population)
  • CHD death rates increased with age, with around half of all CHD deaths (48%) occurring in persons aged 85 and over. CHD death rates for males and females were highest in the 85 and over age group (1,900 and 1,500 per 100,000 population)—4 times as high for males and 6 times as high for females aged 75–84 (473 and 238 per 100,000 population) (Figure 8)
  • CHD was responsible for a large proportion of premature deaths before age 75, especially in the male population—37% of males dying from CHD were aged less than 75 years, compared with 15% of females.

Figure 8: Coronary heart disease death rates, by age and sex, 2019

The bar chart shows coronary heart disease death rates by age groups in 2019. Rates were highest among men and women aged 85 and over (1,926 and 1,462 per 100,000 population).

Trends

CHD death rates have been declining in Australia since the late 1960s. Between 1980 and 2019:

  • the number of CHD deaths declined by 42%, from 30,700 to 17,700
  • age-standardised CHD death rates declined substantially, by around 80%—falling from 414 to 73 per 100,000 population for males, and 209 to 37 per 100,000 population for females (Figure 9).

Much of the decline in CHD mortality in Australia over recent decades can be attributed to reductions in levels of population risk factors, including tobacco smoking, abnormal blood lipids and high blood pressure.

Declines in CHD mortality can also be attributed to improvements in medical and surgical treatment. Better emergency care, the use of statins and agents to lower blood pressure and anti-platelet drugs, along with revascularisation procedures, have each contributed to better CHD outcomes, both in and out of hospital.

Evidence from a number of countries attributes lower CHD death rates to improvements in risk factors levels and to better treatment in about equal proportion (AIHW 2017).

Figure 9: Coronary heart disease death rates, by sex, 1980–2019

The line chart shows the decline in age-standardised coronary heart disease death rates between 1980 and 2019, from 414 to 73 per 100,000 population for males and from 209 to 37 for females.

Variation among population groups

Aboriginal and Torres Strait Islander people

CHD is the leading cause of death in the Aboriginal and Torres Strait Islander population.

In 2017–2019:

  • CHD was the underlying cause of death for 1,143 Indigenous people in jurisdictions with adequate Indigenous identification.
  • After adjusting for differences in the age structure of the populations, the CHD death rate for Indigenous Australians was twice as high as for non-Indigenous Australians (118 and 55 deaths per 100,000 population).
  • CHD death rates for Indigenous males and females were 2.1 and 2.3 times as high as for non-Indigenous males and females (Figure 10).

Socioeconomic group

  • In 2017–2019, the CHD death rate was 1.6 times as high for people living in the lowest socioeconomic areas compared with those living in the highest socioeconomic areas (age-standardised rates of 70 and 43 per 100,000 population).
  • The difference was greater for males (1.7 times as high) than females (1.5 times as high (Figure 10).

Remoteness area

  • In 2017–2019, the CHD death rate was 1.6 times as high in Remote and very remote areas compared with Major cities (age standardised rates of 82 and 53 per 100,000 population).
  • The male CHD death rate in Remote and very remote areas was 1.5 times as high as in Major cities (108 and 71 deaths per 100,000 population), and the female rate 1.4 times as high (53 and 37 per 100,000 population) (Figure 10).

Figure 10: Coronary heart disease rates, by population group and sex, 2017–2019

The horizontal bar chart shows that coronary heart disease death rates in 2017–2019 were higher among Indigenous Australians, people living in the lowest socioeconomic areas, and people living in remote and very remote areas.