Cardiovascular disease (CVD) remains the leading cause of mortality in the UK, with the latest statistics documenting that almost one-third of all deaths are currently attributed to the condition.1 Current UK government guidelines implemented through the National Institute for Health and Care Excellence (NICE) advocate risk assessment of individuals aged 40–74 years to identify those at ‘high risk’ (≥20% 10-year risk of developing CVD).2 Early identification of individuals at elevated risk is essential so that lifestyle modification or pharmacological interventions can be prescribed to alleviate the risk of disease.3 It is recommended that validated equations should be used to assess CVD risk and up until February 2010, the Framingham Risk Equation4 was the ‘equation of choice’ before this endorsement was withdrawn.2 The amended NICE guidelines now encourage healthcare professionals to use the cardiovascular risk equation that they feel most appropriate.2,5
Previous research has highlighted differences in false-positive rates (at a 20% threshold) between six widely cited CVD risk algorithms,6 despite these differences the screening performance of the six was similar. It was concluded that age remains the most dominant predictor in CVD events despite individual risk factors being present.6 This observation is somewhat surprising, especially as 80% of all premature coronary heart disease in males can be attributed to the combination of smoking, hypertension, and high levels of total cholesterol (>5.2 mmol/l).7 In further terms of CVD risk factors, there is evidence that a multifactorial strategy treating glycaemic control, lipid profiles, and blood pressure together through either medication or behavioural therapy has been shown to be highly effective in reducing cardiovascular mortality compared with conventional treatment.8
Statin therapy is recommended as part of the management strategy for primary prevention of CVD for adults at high risk of developing CVD.2,9 Treatment should be initiated with simvastatin (40 mg) in those adults who have a ≥20% 10-year risk of developing CVD.2 Therefore, any differences between predicted risk equations could have a number of implications for the correct treatment of individuals (such as either over- or underprescribing statins as a primary treatment) and the associated costs of medications.
How this fits in
Up until February 2010 the ‘equation of choice’ of NICE to determine cardiovascular disease (CVD) risk was the Framingham Risk Equation, with the guidance now encouraging healthcare professionals to adopt the equation that they deem ‘most appropriate’. This research compares four commonly-used CVD risk equations in the UK and examines the number of individuals predicted at ‘high risk’. The JBS2 and Framingham BMI equations predicted a higher proportion of individuals at ‘high risk’ of CVD than the Framingham Lipids or QRISK2 algorithms. Furthermore, despite changes in absolute risk prediction after age stratification in all of the equations, there are few differences between isolated risk factors.
This study primarily compared four commonly-used CVD risk equations when the same individual dataset was applied, and examined if isolated risk factors translated to ‘high risk’ of CVD.