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Introduction 

The Joint British Societies Cardiovascular Risk Assessor calculates your percentage likelihood of developing CVD, cardiovascular disease (CHD and stroke added together) over a 10 year period e.g. a risk of 15% means that there is a 15 in 100 chance of a CVD event in the next 10 years.

Diseases of the heart and circulatory system (cardiovascular disease or CVD) are the main cause of death in the UK and account for over 208,000 deaths each year.  More than one in three people (36%) die from CVD each year.  The main forms of CVD are coronary heart disease (CHD) and stroke.

Guidelines

The programme is for estimating cardiovascular disease (CVD) risk (non-fatal myocardial infarction, stroke and TIA, coronary and stroke death and new angina pectoris) for individuals who have not already developed coronary heart disease or other major atherosclerotic disease.  It is an aid to making clinical decisions about how intensively to intervene on lifestyle and whether to use antihypertensive, lipid lowering and anti-platelet medication, but should not replace clinical judgment.

The programme is primarily to assist in directing intervention for those who typically stand to benefit most, but there may be others who in the view of the clinician should also be considered for intervention. The use of the programme is not appropriate for people who have existing diseases or are at higher risk for other medical reasons.

 Examples are:

•     Coronary heart disease or other major atherosclerotic disease
•     Familial hypercholesterolemia or other inherited dyslipidaemias
•     Renal dysfunction
•     Type 1 and 2 diabetes mellitus

The programme should not be used to decide whether to introduce antihypertensive medication when blood pressure is persistently at or above 160/100 or when target organ damage due to hypertension is present. In both cases antihypertensive medication is recommended regardless of CVD risk. Similarly the programme should not be used to decide whether to introduce lipid-lowering medication when the ratio of serum total to HDL cholesterol exceeds 6. Such medication is generally then indicated regardless of estimated CVD risk.

Factors affecting JBS Cardiac Risk

Gender, age, Systolic Blood Pressure, Diastolic Blood Pressure, smoking status, total serum cholesterol, HDL cholesterol and left ventricular hypertrophy are used to calculate absolute CVD risk exactly according to the equations of Anderson and colleagues.  Diabetes or a fasting blood glucose of 7mmol/l or more are exclusions.

• Impaired fasting glucose (in the range 6.1 - 6.9mmol/l) increases CVD risk by 1.5 times.
• South Asian origin increases CVD risk by 1.5 times.
• Adverse family history increases CVD risk by 1.5 times. 
• Serum triglyceride of 1.7mmol/l or more increases CVD risk by 1.3 times.

If any combination of impaired fasting glucose, South Asian origin, adverse family history or raised serum triglyceride occurs, risk is only increased by whichever of these factors in the combination gives the highest risk. None of them increase risk further in the programme when left ventricular hypertrophy is present.

Left ventricular hypertrophy increases risk so much that further multiplying risk to take into account other factors is likely to be inaccurate. Also although, for example it can be shown that raised serum triglyceride increases risk by about 1.3 times, including triglyceride in a multivariate equation will reduce the variation in risk explained by the other risk factors.

Successively multiplying risk for factors not included in the original equations of Anderson and colleagues will thus lead to gross overestimations of risk. On the other hand, the clinician should be aware in making clinical decisions that combinations of risk factors such as family history, high triglyceride, South Asian origin, impaired fasting glucose are likely to increase risk above that shown by the programme.