Notes

• **In the original Anderson paper¹, the CVD group was a very mixed bag of conditions, consisting of MI and CHD death (plus angina pectoris and coronary insufficiency), stroke (including transient ischemia) plus congestive heart failure and peripheral vascular disease. This is not a good match to the CVD end-point in statin and hypertension trials and should not be used.² The BHF/CVRA calculator³ calculates CVD risk as the sum of CHD risk and stroke risk (JBS Risk option in calculator above) as this is in better agreement with the original New Zealand CVD risk charts - so can be used as an alternative to the printed CVD risk charts.
• The following patients should not have their risk calculated - as they are considered already to be at high enough risk to justify lifestyle and other interventions (antithrombotic, antihypertensive and lipid lowering therapies).⁴
  • Patients with atherosclerotic cardiovascular disease
  • Hypertension (≥160/100 mmHg) with target organ damage
  • TC to HDL-C ratio ≥6
  • Patients with type 1 or 2 diabetes mellitus
  • Renal dysfunction (including diabetic nephropathy)
  • Familial hypercholesterolaemia, familial combined hyperlipidaemia or other inherited dyslipidaemia
• The following patients have higher risks:
  • Significant family history (Men <55 and women <65 years) increases risk by a factor of 1.5; as does impaired fasting glucose and South Asian origin.⁵
  • Obesity (BMI ≥30 kg/m² (especially central obesity men with waists ≥102 in white caucasians (≥90 cm in asians). Corresponding waist values for women are ≥88cm and ≥80 cm). Obesity increases risk by a factor of 1.3.
  • Serum triglyceride of 1.7mmol/l or more increases CVD risk by 1.3 times (this calculator treats it the same as obesity). A low HDL cholesterol (< 1.0 mmol/l in men and <1.2 mmol/l in women) also increases risk.
  • 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. In this calculator, none of them increases the risk further when left ventricular hypertrophy is present - as left ventricular hypertrophy increases risk so much that further multiplying risk to take into account other factors is likely to be inaccurate.⁴
    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.
• New ideal targets for total cholesterol reduction are <4.0 mmol or a 25% reduction (or LDL to <2.0 or a 30% reduction), whichever is the greater.⁴
• Use pre-treatment values where available - using or substituting values on treatment are only a guide to risk trends and probably under-estimate actual risk. If pre treatment values not available JBS 2 suggests using BP of 160/90, and a total cholesterol/HDL ratio of at least 6.⁴
• LVH = definite LVH on ECG.
• Patients should be considered smoker = if they currently smoke or in first few years of stopping. Actual increased risk of ex smokers will depend on lifetime exposure to cigarettes, and will lie between the never smoked and still smoking values.