Aus CVD risk: the Australian cardiovascular disease risk calculator

Case scenario

Naama, a 53-year-old female, presents at the pharmacy with some new prescriptions which include a blood pressure (BP) medicine and nicotine patches. She is ready to start her quit smoking journey but is unsure about lowering her blood pressure if it means taking pills. She recalls the doctor performing a heart health check and showing her a website which illustrated her risk of having a heart attack in the next 5 years, which she is very concerned about. She has a follow-up appointment with her GP in 3 months.

Other information you gather: Systolic BP 150, total cholesterol 3.9 mmol/L, high-density lipoprotein (HDL) 1.1 mmol/L, postcode 5670, Sri Lankan heritage. She is not on any medicines currently.

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Introduction

A person’s risk of developing cardiovascular disease (CVD) depends on the combined effect of multiple risk factors. Risk assessment remains fundamental to the primary prevention of CVD.

Several risk factors contribute to an individual’s chances of developing CVD. These include¹:

• lifestyle factors (e.g. smoking, lack of physical activity, poor diet)
• biomedical factors (e.g. hypertension, abnormal blood lipid levels)
• non-modifiable factors (e.g. age and sex).

Pharmacists can encourage modification of early CVD risk factors, inform targeted pharmacotherapy and support clinical decision-making.

Impact of cardiovascular disease

CVD is a significant cause of morbidity and mortality in Australia, with ischaemic heart disease remaining the leading cause of death over the past decade.^1,2

In 2020–21, CVD was responsible for an estimated 9.5% of total healthcare expenditure in Australia, or $14.3 billion.¹ In 2022, 6.7% of adults had one or more cardiovascular conditions, and CVD was responsible for taking one Australian life every 12 minutes (24% of all deaths).^1,3

Despite remaining the leading cause of death, in 2023 the Australian Institute of Health and Welfare reported a reduction in age-adjusted ischaemic heart disease mortality rates to the lowest since official cause of death statistics began in 1968.¹ This may be attributed to research, improved knowledge of risk factors, improved interventions and increased public knowledge of CVD.^3,4

Background of the Aus CVD Risk calculator

CVD assessment and treatment using a validated risk equation is considered international best practice and guides CVD management in primary care, so the risk equations must quantify the risk as accurately as possible.⁵ The Aus CVD Risk calculator is based on an equation developed from a large New Zealand cohort study and has been modified statistically to match the CVD rates for the Australian population through a process called recalibration.⁵ It is intended for use by GPs, nurses, Aboriginal health workers and practitioners, allied health professionals and other professionals who support the primary prevention of CVD.⁵

The Aus CVD Risk calculator was developed in conjunction with its overarching clinical guideline, the Australian Guideline for Assessing and Managing Cardiovascular Disease Risk,⁶ and replaces the previous 2012 CVD risk calculator and guideline.⁷ The 2023 guideline and calculator provide updated evidence-based recommendations for identifying, assessing, communicating and managing CVD risk in a primary prevention setting.⁵

Using the Aus CVD Risk calculator

The calculator is openly accessible at cvdcheck.org.au.⁵ It guides the user through the five-step process of:

1. Identifying people for CVD risk assessment
2. Calculating CVD risk
3. Identifying the CVD risk category
4. Reclassification factors (e.g. ethnicity, family history of premature CVD, chronic kidney disease, severe mental illness, coronary artery calcium score)
5. Communicating CVD risk
6. Managing CVD risk.

1. Identifying people for assessment

Risk calculation is recommended for people without known CVD. Those who have previously experienced a major event should be managed under secondary care arrangements (refer to Therapeutic Guidelines for further information). People with moderate-to-severe chronic kidney disease or familial hypercholesterolaemia should be automatically managed as having high CVD risk.⁶

The recommended age ranges for estimating CVD risk using Aus CVD Risk are⁶:

• all people aged 45–79 years
• people with diabetes aged 35–79 years
• First Nations people aged 30–79 years (assessing individual risk factors for those aged 18–29 years).

2. Calculating risk

The Aus CVD Risk calculator estimates the overall risk of a person by considering multiple risk factors, rather than individual risk factors in isolation. Risk factors added to the calculator include, but are not limited to age, sex at birth, smoking status, diabetes, blood pressure and lipid profile.⁶ History of taking CVD medicines, medical history of atrial fibrillation, with additional diabetes-specific variables, assist in calculating more accurate assessment in individuals.

The Aus CVD Risk calculator also utilises the patient’s postcode to incorporate Socio-Economic Indexes for Areas (SEIFA) quintiles. SEIFA is a population-level summary measure that reflects determinants such as education, housing, employment and income, and provides a way to incorporate socioeconomic status into CVD risk assessment.⁶

Variables are inputted into the Aus CVD Risk calculator and presented as a percentage, representing an individual’s probability of a major cardiovascular event (such as myocardial infarction, angina, other coronary heart disease, stroke, transient ischaemic attack, peripheral vascular disease, congestive heart failure or other ischaemic CVD-related condition) in the next 5 years.^5,6

3. Identifying risk category

The calculator stratifies people into one of three risk categories, estimating the chance of experiencing a major cardiovascular event in the next 5 years⁶:

• high (≥10% risk over 5 years)
• intermediate (5 to <10% risk over 5 years)
• low (<5% risk over 5 years).

The risk category informs CVD management, including encouraging and supporting healthy lifestyle and behaviours, and targeting pharmacotherapy to those who will benefit most.

The calculator also allows reclassification of an individual’s risk, particularly when the calculated risk is close to a risk category threshold. Reclassification can be upward or downward according to ethnicity or coronary artery calcium score, or upward with substantiated premature CVD family history, chronic kidney disease or personal severe mental illness.

There are also other clinical conditions, investigations and blood biomarkers that are associated with increased CVD risk in some people. For some, the accuracy of CVD risk prediction is not improved by incorporating additional risk weighting beyond what is currently measured. For others, evidence is still emerging. Healthcare professionals are encouraged to explain to people within these groups the elevated risk and the need for monitoring, and the importance of leading a healthy lifestyle⁶:

• chronic inflammatory conditions
  (e.g. rheumatoid arthritis)
• history of pregnancy complications (e.g. hypertensive disorders of pregnancy (pre-eclampsia) and gestational diabetes)
• premature or early menopause
• other lipid fractions not captured by the calculator
• polygenic risk scores
• COVID-19.

For further information please refer to Australian Guideline for Assessing and Managing Cardiovascular Disease Risk.⁶

4. Communicating risk

The calculator uses evidence-based decision aids to support effective communication and enable shared decision-making to reduce CVD risk. Communicating risk is essential for informed consent, and the guideline recommends communicating risk in a variety of formats depending on the health literacy needs and learning styles of the patient. These may include communicating risk as a percentage or using the interactive visual tools embedded in the calculator.⁶

Cultural safety is a key consideration when communicating risk.⁶ The guideline advises to also consider and communicate the need for referral to other healthcare professionals, when required, to help the patient address cardiovascular risk.⁶

5. Managing risk

Managing CVD risk should always involve a collaborative approach and should be encouraging, supportive, and include advice on appropriate healthy lifestyle and behaviours, with or without BP-lowering and/or lipid-modifying pharmacotherapy.

Approaches to addressing lifestyle factors include smoking cessation, adopting healthy eating patterns, regular physical activity, achieving and maintaining a healthy weight, and limiting intake of alcohol.

See the Australian Guideline for Assessing and Managing Cardiovascular Disease Risk⁶ for management recommendations according to risk category.

Knowledge to practice

Pharmacists can play a significant role in supporting primary prevention of CVD by identifying and assessing at-risk patients, and referring on to a GP for further assessment where necessary. The Aus CVD Risk calculator is a helpful tool to support healthcare professionals, including pharmacists, assess potential risk of a major cardiovascular event in the next 5 years.

Pharmacists can also actively support CVD risk education in their day-to-day practice and support people to help maintain or improve their cardiovascular health through lifestyle approaches, in particular smoking cessation, and use of medicines when prescribed.

Conclusion

Pharmacists are a reliable source of health information and can help people understand their risk of CVD to facilitate informed decisions about management options. Pharmacists are a regular connection, particularly for those on pharmacotherapy, and can check in with people to support, encourage and advise them with management options whether pharmacological or lifestyle.

If you do get an enrolment error, please click here

Key points

• The 2023 Aus CVD Risk calculator and guideline provide updated evidence-based recommendations for identifying, assessing, communicating and managing CVD risk in a primary prevention setting.
• The calculator includes decision aids that can support effective communication about CVD risk and enable informed decisions about reducing CVD risk.
• Managing CVD risk should always include advice on appropriate healthy lifestyle and behaviours.

References 

1. Australian Institute of Health and Welfare. Heart, stroke and vascular disease: Australian facts. 2024. At: www.aihw.gov.au/reports/heart-stroke-vascular-diseases/hsvd-facts/contents/impacts/expenditure-cvd
2. Australian Bureau of Statistics. Causes of Death, Australia. 2024. At: www.abs.gov.au/statistics/health/causes-death/causes-death-australia/latest-release
3. Heart Foundation. Key statistics: cardiovascular disease.  At: www.heartfoundation.org.au/your-heart/evidence-and-statistics/key-stats-cardiovascular-disease
4. Australian Bureau of Statistics. Fifty years of reductions in cardiovascular deaths. 2020. At: www.abs.gov.au/articles/fifty-years-reductions-cardiovascular-deaths
5. Commonwealth of Australia as represented by the Department of Health and Aged Care. Aus CVD Risk. 2024. At: www.cvdcheck.org.au
6. Commonwealth of Australia as represented by the Department of Health and Aged Care. Australian Guideline for assessing and managing cardiovascular disease risk. 2023. At: https://d35rj4ptypp2hd.cloudfront.net/pdf/Guideline-for-assessing-and-managing-CVD-risk_20230522.pdf
7. Heart Foundation. The guideline and calculator help healthcare professionals assess, communicate and manage a person’s risk of developing cardiovascular disease. 2023. At: www.heartfoundation.org.au/for-professionals/guideline-for-managing-cvd

Our author

Lisa Kalman BPharm is a pharmacist who works in digital health technology. She led the project to develop the Aus CVD Risk calculator and its associated clinical guideline, the Australian Guideline for Assessing and Managing Cardiovascular Disease Risk. She is currently leading the work to integrate the calculator into primary care software, aligning with the federal government’s roadmap towards interoperability for the Australian health system.

Our reviewer

Julie Briggs (she/her) BPharm, MPS, AcSHP

Conflict of interest declaration

Lisa Kalman works for the National Heart Foundation of Australia, a not-for-profit organisation, which received federal government funding for the development of Aus CVD Risk. There were no, and are no, commercial interests in the development of this tool.