How to know your heart attack risk
In medicine, we talk about something called ‘‘cardiovascular risk’’ (CVR) – in lay terms, this is simply a way of assessing an individual’s risk profile for cardiovascular disease, and combining the different factors to come up with a score.
This score reflects the chance that someone will suffer from either a heart attack or a stroke – so if the score is 10 per cent, it means that 1 in 10 people with the same combination of risk factors will have one of those medical issues in the next five years.
Obviously it isn’t perfect, but this is a surprisingly accurate tool, and a really good way of assessing your whole picture of risk, rather than just identifying and addressing the individual factors.
Cardiovascular disease is our biggest killer – in fact heart attacks and strokes make up 40 per cent of all deaths in New Zealand.
Many of these deaths are actually preventable, so understanding where your risk sits, and intervening if needed to reduce the likelihood of dying from one of these conditions, is important.
An ongoing study called PREDICT based on New Zealand data, has prompted some changes to the system we use here, and how we interpret it, so it seems timely to ensure that we all understand not only how our CVR is assessed, but at what age or stage of life we should go and get this checked. The new way of assessing CVR will take into account the following:
Your age
Your gender
Your family history – if you have had a first degree relative (that is, parent or sibling) who has been hospitalised or died from a heart attack or stroke under the age of 50, or has had type 2 diabetes, this counts as a positive risk factor
Your own medical history – if you have had a previous stroke, heart attack, angina, heart failure, diabetes, peripheral vascular disease (very poor circulation to your hands and feet), or have inherited high cholesterol levels (a condition known as familial hypercholesterolaemia), then your risk of having a subsequent event is increased. Your risk is also increased if you have had severe mental illness and required treatment with antipsychotic medication
Smoking
Blood pressure
Your ‘‘lipid profile’’ – this is a blood test that checks a range of types of lipid, including cholesterol. It takes into account that some lipids are actually protective, while others are a true risk factor
HBA1C – a test for diabetes
EGFR or creatinine – a test of your kidney function
Your body mass index or BMI
Previous medication you have been on, specifically medication to lower blood pressure, cholesterol levels, or clotting risk (such as aspirin).
Whatever your risk level is, adopting a healthy lifestyle, addressing smoking, diet, exercises and weight, is the best way to ensure you stay healthy.
All of these variables can then be put into a system that calculates your risk, and the discussion with your doctor is then what, if anything, you should do to modify it.
It should be noted that this is a way of predicting risk for people who haven’t had heart disease or a stroke before (this is called primary prevention) – if you have, you are considered automatically to be high risk, and will require secondary prevention, with more intensive interventions to lower your future risk.
So when should you get your CVR checked? With the new data we have from PREDICT, CVR screening is recommended for all men from 45 years old and all women from 55. However, if you fall into one of the following groups, you should be screened earlier:
Maori, Pacifica or South Asian people – men should go at 30, and women at 40
People with other known risk factors, or at high risk of developing diabetes (that is, a strong family history, or blood tests showing ‘‘pre-diabetes’’) – men should go at 35, women at 45
People with existing type 2 diabetes – CVR should be done each year with their annual review from the time of diagnosis
People with severe mental illness on antipsychotic medication, CVR screening should be from 25 years old.
Your GP surgery may well have you on their ‘‘recall’’ system, so will automatically let you know when you reach the recommended age – but if you haven’t heard, and should be due to get your screening done, it is worth booking an appointment.
Sometimes, these visits can be subsidised, but check before you book as that isn’t always the case.
How often you should get your CVR checked depends on your risk level.
If you are very high risk, 15 per cent or over, then you will be encouraged to get your screening
done annually, as part of your general health management. However, if you fall into the lowest risk category, 3 per cent or less, you don’t need to do anything further for another 10 years.
If your risk does turn out to be higher than expected, don’t panic – there are plenty of things you can do to reduce it.
Your doctor’s role is to ensure you understand your risk, and then discuss the different options for managing it, with their pros and cons, so you can make an informed choice.
And whatever your risk level is, adopting a healthy lifestyle, addressing smoking, diet, exercises and weight, is the best way to ensure you stay healthy for as long as possible.