Health professionals

What is absolute cardiovascular disease risk?

“Cardiovascular absolute risk assessment is a simple tool that can enhance your clinical judgement, and improve your ability to educate and motivate patients. Single risk factors (like cholesterol level) provide a poor estimate of a patient’s cardiovascular disease risk. Absolute risk assessment provides a more accurate estimate of overall, individualised cardiovascular risk, thereby allowing the clinician to best tailor pharmaceutical and lifestyle management to the patient.”
– Professor Mark Harris, Royal Australian College of General Practitioners, University of New South Wales

The probability that an individual will develop cardiovascular disease within a given period of time depends on the combination and intensity of all their identified risk factors, rather than on the presence of any single risk factor. Using an absolute risk approach takes into account the cumulative and sometimes synergistic effects of these multiple risk factors. Clinical decisions based on absolute cardiovascular disease risk levels can lead to improved health outcomes, because they direct the right treatments to those who can benefit most. The absolute risk approach is emphasised by several Australian and international primary care guidelines, and supported by robust evidence.

Who should have their absolute risk assessed?*

Absolute cardiovascular risk assessment, using the Framingham Risk Equation to predict risk of a cardiovascular event over the next 5 years, should be performed for all adults aged 45 and older (or 35 years and older for Aboriginal and Torres Strait Islander peoples) without existing cardiovascular disease or not already known to be at increased risk of cardiovascular disease (see Box 1 below).

For specific population groups, additional recommendations include:

Commence assessment in Aboriginal and Torres Strait Islander adults at 35 years (rather than 45 years). Although the Framingham Risk Equation might underestimate risk in this population, available evidence suggests that this approach will provide an estimate of minimum cardiovascular risk.
Conduct assessments in adults with diabetes aged 45—60 years (rather than 45—74 years). Although the Framingham Risk Equation might underestimate risk in this population, available evidence suggests that this approach will provide an estimate of minimum cardiovascular risk.
In adults who are overweight or obese, the results of the assessment should be interpreted with the awareness that its predictive value has not been specifically assessed in this population.
In adults with atrial fibrillation (particularly those aged over 65 years), an increased risk of cardiovascular events and all-cause mortality, in addition to thromboembolic disease and stroke, should be taken into account. While cardiovascular disease risk is known to be elevated for this population, it is not possible to quantify the degree of additional cardiovascular disease risk in an individual. Clinical judgement is necessary when assessing overall cardiovascular risk.

Adults with any of the conditions in Box 1 are already known to be at increased absolute risk of cardiovascular disease and do not require further assessment using the Framingham Risk Equation.

Box 1. Adults already known to be at increased absolute risk of cardiovascular disease

Diabetes and age > 60 years
Diabetes with microalbuminuria (> 20 mcg/min or urinary albumin:creatinine ratio > 2.5 mg/mmol for males, > 3.5 mg/mmol for females)
Moderate or severe chronic kidney disease (persistent proteinuria or estimated glomerular filtration rate < 45 mL/min/1.73 m2)
A previous diagnosis of familial hypercholesterolaemia^**
Systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg
Serum total cholesterol > 7.5 mmol/L

What is included in a full absolute risk assessment?

To make a full assessment of your patient’s absolute cardiovascular risk, you will need to take into consideration the following factors:

Age^† and sex^†
Smoking status^†
Serum lipids^†
Blood pressure^†
Waist circumference and body mass index
Nutrition
Physical activity level
Alcohol intake^††
Family history of premature cardiovascular disease
Social history including cultural identity, ethnicity, socioeconomic status^‡ and mental health
Diabetes
Urine for microalbumin and protein
Familial hypercholesterolaemia**
Evidence of atrial fibrillation (history, examination, electrocardiogram)

Further information

For more detailed information, refer to the full NVDPA Guidelines for the assessment of absolute cardiovascular disease risk and the quick reference guide, which includes an assessment algorithm and coloured risk charts. You can find links to these resources and management guidelines on the Resources page.

Footnotes

* Some recommendations were derived from the systematic review, while others are consensus statements developed where the systematic literature review process was undertaken, but no evidence was found for or against the recommendation. For details see NVDPA’s Guidelines for the assessment of absolute cardiovascular disease risk.

** Refer to National Heart Foundation of Australia’s information sheet Familial hypercholesterolaemia: information for doctors.

† Risk parameters that are included in the absolute risk calculator, based on the Framingham Risk Equation.

†† Alcohol is a risk factor for elevated blood pressure (which is itself a major independent determinant of risk of atherosclerotic disease), stroke and cardiomyopathy. For a full discussion of this, please see the National Health and Medical Research Council’s (NHMRC) Australian guidelines to reduce health risks from drinking alcohol.

‡ Risk assessment requires consideration of socioeconomic deprivation as an independent risk factor for cardiovascular disease. Absolute cardiovascular risk calculated using the Framingham Risk Equation is likely to underestimate cardiovascular risk in socioeconomically deprived groups.

An initiative of the National Vascular Disease Prevention Alliance