by Dr. Victor Ng - Web Editor
The HeART Calculator provides an estimation of the 10 Year CHD (coronary heart disease) Risk Score. The formula for deriving the score is based on the Framingham-based NCEP ATP III 10 Year Risk Score Tables which have been modified taking into account the Singapore cardiovascular epidemiological data. The modification is carried out as part of a collaboration between investigators at the Singapore Ministry of Health, Singapore General Hospital, National University of Singapore and Prof. Ralph B D’Agostino from the Framingham Heart Study, USA.
The principal of use is to provide a guideline for risk reduction therapy and how it should be adjusted to a person’s risk of developing future coronary events; this is the basic principle in the prevention of CHD. The data and subsequent risk score tables as formularized took into account obvious ethnic differences inferred from epidemiological studies. The HeART Calculator simplifies the mathematical process. For ethnic minorities (other than Chinese, Malay and Indians), it is recommended that the 10 year CHD Risk Score be calculated based on that for the lowest risk group (ie. Chinese).
In the accompanying article titled ‘Sudden Death and Atherosclerosis’, the importance and steps required have already been documented. To summarize:
The first step is to assess an individual’s risk status.
The 3 risk group categories are:
- High Risk (10 year CHD risk >20%)
- Intermediate Risk (10 year CHD risk 10-20%)
- Low Risk (10 year CHD risk <10%)
For the purpose of risk assessment, the 10 year CHD risk refers to the risk of having myocardial infarction (heart attack) or coronary death in the next 10 years.
Step 1
The following automatically fall into the High Risk Group:
1) Individuals with established CHD
2) Individuals with CHD Risk Equivalents. Eg. Diabetes Mellitus, atherosclerotic cerebrovascular disease, peripheral artery disease or abdominal aortic aneurysms.
Estimation of the 10 year CHD risk score in these individuals is not necessary.
Step 2
For all other individuals, count how many risk factors using the following:
- Total cholesterol = or > 240 mg/dl (6.2 mmol/L) or
LDL cholesterol = or > 160 mg/dl (4.1 mmol/L)
- Cigarette smoking
- Hypertension (BP = or > 140/90 mmHg or on anti-hypertensive treatment)
- Low HDL cholesterol (< 40 mg/dl [< 1.0 mmol/L])
- Family history of premature CHD (CHD in male first degree relative < 55 years; CHD in female first degree relative < 65 years)
- Age (men = or > 45 years; women = or > 55 years)
- Indian ethnicity
If the individual has 0-1 risk factor, this person automatically falls into the Low Risk Group. Estimation of the 10 year CHD risk score is not necessary.
Step 3
If the individual has = 2 risk factors, estimation of the 10 year CHD Risk Score using the HeART Calculator is recommended. To input the data required, you will need to have baseline measurements for your Blood Pressure, Total Cholesterol Level and HDL Cholesterol Level.
When you have input the data required, the risk status will be classified as:
1) > 20% = high risk
2) 10 to 20% = intermediate risk
3) < 10% = low risk
To reduce the risk of CHD, priority is given to optimize the LDL Cholesterol level and for now, the following guidelines are recommended:
LDL-C HDL-C Triglyceride
mmol/L (mg/dL) mmol/L (mg/dL) mmol/L (mg/dL)
High Risk Group <2.6 (100) =1.0 (40) <2.3 (200)
Intermediate Risk <3.4 (130) =1.0 (40) <2.3 (200)
Low Risk Group <4.1 (160) =1.0 (40) <2.3 (200)
Lifestyle changes including but not limited to the following are also recommended:
- Cessation of cigarette smoking
- Weight reduction if you are overweight (check your BMI)
- Regular exercise
- Proper diet
- Reduce stress; rest and recreation
Data and information used above and those applied to the HeART calculator are provided by The Ministry of Health, Singapore. Clinical Practice Guidelines 2/2006. Lipids. May 2006.
Available from: http://www.moh.gov.sg/corp/publications/list.do?id=pub_guide_clinics