Patches of atheroma are like small fatty lumps that develop within the
inside lining of arteries (blood vessels). Atheroma is also known as
'atherosclerosis' and 'hardening of the arteries'. Patches of atheroma
are often called 'plaques' of atheroma.
A patch of atheroma
makes an artery narrower. This can reduce the blood flow through the
artery. In time, patches of atheroma can become larger and thicker.
Sometimes,
a patch of atheroma may develop a tiny 'crack' on the inside surface of
the blood vessel. This may trigger a blood clot (thrombosis) to form
over the patch of atheroma which may completely block the blood flow.
Depending on the artery affected, a blood clot that forms on a patch of
atheroma can cause a heart attack, a stroke, or other serious problems.
What are the cardiovascular diseases caused by atheroma?
Heart disease
The term 'heart disease', or
'coronary heart disease', is used for conditions caused by narrowing of
one or more of the coronary (heart) arteries by atheroma. The problems
this can cause include angina, heart attack, and heart failure. Heart
disease is common in the UK in people over 50.
Note: it can be
confusing as there are other heart conditions such as heart valve
problems, congenital heart problems, etc. However, these are not
usually included when we talk about 'heart disease'.
Cerebrovascular disease - stroke and TIA
Cerebrovascular
disease means a disease of the arteries in the brain (cerebrum). The
problems this can cause include a stroke and a TIA (transient ischaemic
attack). A stroke means that part of the brain is suddenly damaged. The
common cause of a stroke is due to an artery in the brain which becomes
blocked by a blood clot (thrombus). The blood clot usually forms over
some atheroma. A TIA is a disorder caused by temporary lack of blood
supply to a part of the brain.
Peripheral vascular disease
Peripheral
vascular disease is narrowing due to atheroma that affects arteries
other than arteries in the heart or brain. The arteries that take blood
to the legs are the most commonly affected.
If you can prevent
a build up of atheroma in the arteries, you are less likely to develop
the above diseases. If you already have one of the above diseases, you
may prevent or delay it from getting worse if you prevent further
build-up of atheroma.
Risk factors
Everybody has some risk of developing atheroma. However, certain 'risk factors' increase the risk. Risk factors include:
- Lifestyle risk factors that can be prevented or changed:
- Smoking.
- Lack of physical activity (a sedentary lifestyle).
- Obesity.
- An unhealthy diet and eating too much salt.
- Excess alcohol.
- Treatable or partly treatable risk factors:
- Hypertension (high blood pressure).
- High cholesterol blood level.
- High triglyceride (fat) blood level.
- Diabetes.
- Kidney diseases causing diminished kidney function.
- Fixed risk factors - ones that you cannot alter:
- A
strong family history. This means if you have a father or brother who
developed heart disease or a stroke before they were 55, or in a mother
or sister before they were 65.
- Being male.
- An early menopause in women.
- Age. The older you become, the more likely you are to develop atheroma.
- Ethnic group. For example, people who live in the UK with ancestry
from India, Pakistan, Bangladesh, or Sri Lanka have an increased risk.
However, if you have a fixed risk factor, you may want to make
extra effort to tackle any lifestyle risk factors that can be changed.
Note: some risk factors are more 'risky' than others. For
example, smoking probably causes a greater risk to health than obesity.
Also, risk factors interact. So, if you have two or more risk factors,
your health risk is much more increased than if you just have one. For
example, a middle aged male smoker who does little physical activity
and has a strong family history of heart disease has quite a high risk
of developing a cardiovascular disease such as a heart attack or stroke
before the age of 60.
Research is looking at some other factors
that may be risk factors. For example, high blood levels of fibrinogen,
C reactive protein, apolipoprotein B, and homocysteine are being
investigated as possible risk factors.
Known risk factors that can be prevented, changed or treated are now discussed further.
Lifestyle risk factors that can be prevented and/or changed
Smoking
Lifetime smoking roughly doubles
your risk of developing heart disease. The chemicals in tobacco get
into the bloodstream from the lungs and damage the arteries and other
parts of the body. Your risk of having a stroke, and developing other
diseases such as lung cancer are also increased. Stopping smoking is
often the single most effective thing that a person can do to reduce
their health risk. The increased risk falls rapidly after stopping
smoking (although it takes a few years before the excess risk reduces
completely). If you smoke and are having difficulty in stopping, then
see your practice nurse for help and advice.
Lack of physical activity - a sedentary lifestyle
People
who are physically active have a lower risk of developing
cardiovascular diseases compared to inactive people. To gain health
benefits you should do at least 30 minutes of moderate physical
activity, on most days (at least five days per week).
-
30 minutes in a day
is probably the minimum to gain health benefits. However, you do not
have to do this all at once. For example, cycling to work and back 15
minutes each way adds up to the total of 30 minutes.
-
Moderate physical activity means that you get warm, mildly
out of breath, and mildly sweaty. For example: brisk walking, jogging,
swimming, cycling, etc. However, research studies do suggest that the
more vigorous the exercise, the better for health - particularly for
preventing heart disease.
-
On most days. You cannot 'store up' the benefits of physical activity. You need to do it regularly.
Obesity and overweight
On average, if you
are obese and reduce your weight by 10%, your chance of dying at any
given age is reduced by about 20%. This is mainly because you are less
likely to develop cardiovascular diseases, diabetes, or certain
cancers. The increased health risk of obesity is most marked when the
excess fat is mainly in the abdomen rather than on the hips and thighs.
As a rule, a waist measurement of 102 cm or above for men (92 cm for
Asian men) and 88 cm or above for women (78 cm for Asian women) is a
significant health risk.
Diet
Eating healthily helps to control
obesity, and lower your cholesterol level. Both of these help to reduce
your health risk. Also, there is some evidence that eating oily fish
(herring, sardines, mackerel, salmon, kippers, pilchards, fresh
tuna, etc) helps to protect against heart disease. It is probably the
'omega-3 fatty acids' in the fish oil that helps to reduce the build-up
of atheroma. Also, fruit and vegetables, as well as being low in fat,
also contain 'antioxidants' and vitamins which may help to prevent
atheroma building up. Briefly, a healthy diet means:
- AT LEAST five portions, ideally more, of a variety of fruit and vegetables per day.
- THE BULK OF MOST MEALS should be starch-based foods (such as
cereals, wholegrain bread, potatoes, rice, pasta), plus fruit and
vegetables.
- NOT MUCH fatty food such as fatty meats, cheeses, full-cream milk,
fried food, butter, etc. Use low fat, mono-, or poly-unsaturated
spreads.
- INCLUDE 2-3 portions of fish per week. At least one of which should
be 'oily' (such as herring, mackerel, sardines, kippers, salmon, or fresh tuna).
- LIMIT SALT to no more than 6 g a day (and less for children). See below for details.
- If you eat meat it is best to eat lean meat, or poultry such as chicken.
- If you do fry, choose a vegetable oil such as sunflower, rapeseed or olive oil.
Salt
Adults should eat no more than 6 g salt
a day. This is about a teaspoon of salt. A research study followed up
people for several years and looked at their salt intake. Those who cut
back from about 10 g per day to about 7 g per day or less, on average,
reduced their risk of developing a cardiovascular disease by about a
quarter. So, even a modest reduction in intake can make quite a big
difference. The current average daily intake of salt in the UK is 9 g
per day. About three quarters of the salt we eat is already in the
foods we buy. By simply checking food labels and choosing foods with
lower salt options, it can make a big difference. A tip: sodium is
usually listed on the food label. Multiplying the sodium content by 2.5
will give the salt content. Also, try not to add salt to food at the
table.
Alcohol
Drinking a small or moderate amount
of alcohol probably reduces the risk of developing cardiovascular
diseases. That is, 1-2 units per day - which is up to 14 units per
week. Drinking more than 15 units per week does not reduce the risk,
and drinking more than the recommended upper limits can be harmful.
That is, men should drink no more than 21 units per week (and no more
than four units in any one day). Women should drink no more than 14
units per week (and no more than three units in any one day). One unit
is in about half a pint of normal strength beer, or two thirds of a
small glass of wine, or one small pub measure of spirits.
Other treatable or partially treatable risk factors
A 'risk factor calculator' is commonly used by
doctors and nurses. This can assess your cardiovascular health risk. A
score is calculated which takes into account all your risk factors such
as age, sex, smoking status, blood pressure, cholesterol level, etc.
The calculator has been devised after a lot of research that monitored
thousands of people over a number of years. The score gives a fairly
accurate indication of your risk of developing a cardiovascular disease
over the next 10 years. If you want to know your 'score', see your
practice nurse or GP.
Who should have their cardiovascular health risk assessed?
Current UK guidelines advise that the following people should be assessed to find their cardiovascular health risk:
- All adults aged 40 or more.
- Adults of any age who have:
- A strong family history of early
cardiovascular disease. This means if you have a father or brother who
developed heart disease or a stroke before they were 55, or in a mother
or sister before they were 65.
- A first degree relative (parent, brother, sister, child) with a
serious hereditary lipid disorder. For example, familial
hypercholesterolaemia or familial combined hyperlipidaemia. These
diseases are uncommon.
If you already have a cardiovascular disease or diabetes then
your risk does not need to be assessed. This is because you are already
known to be in the high risk group.
What does the assessment involve?
A doctor or nurse will:
- Do a blood test to check your cholesterol and glucose (sugar) level.
- Measure your blood pressure and your weight.
- Ask you if you smoke.
- Ask if there is a history of cardiovascular diseases in your family
(your blood relations). If so, at what age the diseases started in the
affected family members.
A score is calculated based on these factors plus your age and
your sex. An adjustment to the score is made for certain other factors
such as strong family history and ethnic origin.
What does the assessment score mean?
You are
given a score as a % chance. So, for example, if your score is 30% this
means that you have a 30% chance of developing a cardiovascular disease
within the next 10 years. This is the same as saying a 30 in 100 chance
(or a 3 in 10 chance). In other words, in this example, 3 in 10 people
with the same score that you have will develop a cardiovascular disease
within the next 10 years. Note: the score cannot say if you will be one
of the three. It cannot predict what will happen to each individual
person. It just gives you the odds.
You are said to have a:
- High
risk - if your score is 20% or more. That is, a 2 in 10 chance or more
of developing a cardiovascular disease within the next 10 years.
- Moderate risk - if your score is 10-20%. That is, between a 1 in 10 and 2 in 10 chance.
- Low risk - if your score is less than 10%. That is, less than a 1 in 10 chance.
Who should be treated to reduce their cardiovascular health risk?
Treatment to reduce the risk of developing a cardiovascular disease is usually offered to people with a high risk. That is:
- People
with a risk assessment score of 20% or more. That is, if you have a 2
in 10 chance or more of developing a cardiovascular disease within the
next 10 years.
- People with an existing cardiovascular disease. This is to lower
the chance of it getting worse, or of developing a further disease.
- People with diabetes. If you have diabetes, the time that treatment
is started to reduce cardiovascular risk depends on factors such as:
your age, how long you have had diabetes, your blood pressure, and and
if you have any complications of diabetes.
- People with certain kidney disorders.
What treatments are available to reduce the risk?
If you are at high risk
If you are at high
risk of developing a cardiovascular disease then drug treatment is
usually advised along with advice to tackle any lifestyle issues. This
usually means:
- Drug treatment, usually with a statin drug,
to lower your cholesterol level. No matter what your current
cholesterol level, drug treatment is advised. The aim is to reduce the
level by 25% or to get the level under 4 mmol/l - whichever is the
biggest reduction. See leaflet called 'Cholesterol' for details.
- Drug treatment to lower blood pressure if it is high. This is even
if your blood pressure is just mildly high. See leaflet called 'High Blood Pressure' for details.
- A daily low dose of aspirin (75 mg daily) - depending on your age
and other factors. Aspirin helps to prevent blood clots from forming on
patches of atheroma. See leaflet called 'Aspirin to Prevent Blood Clots' for details.
- Where relevant, to encourage you even more to tackle lifestyle risk factors. This means to:
- stop smoking if you smoke
- eat a healthy diet - including keeping your salt intake to under 6 g a day
- keep your weight and waist in check
- take regular physical activity
- cut back if you drink a lot of alcohol
If available, and if required, you may be offered a referral to a
specialist service. For example, to a dietician to help you to lose
weight and eat a healthy diet, to a specialist 'stop smoking clinic',
or to a supervised exercise programme.
For details on exactly how much risk is reduced by lowering and
treating risk factors, see the guidance produced by the Clincal
Knowledge Services called 'Cardiovascular Risk' - www.cks.library.nhs.uk/cardiovascular_risk
What if I am at moderate or low risk?
If you
are not in the high risk category, it does not mean you have no risk -
just a lesser risk. Drug treatment is not usually prescribed. However,
you may be able to reduce whatever risk you do have even further by any
relevant changes in lifestyle (as described above).
Some people
with a moderate risk buy a low dose statin drug from a pharmacy to
lower their cholesterol level. (Statin drugs are available on
prescription and funded by the NHS if your risk is high. However, you
need to buy them if your risk is not in the high category. But, if you
do buy a statin and take it regularly, it is best to let you doctor
know so that it can be put on your medical record.)
Further help and information
British Heart Foundation
14 Fitzhardinge Street, London, W1H 6DH
Tel (Heart Help Line): 08450 70 80 70 Web: www.bhf.org.uk
Heart UK
7 North Road, Maidenhead, Berkshire, SL6 1PE
Helpline: 0845 450 5988 Web: www.heartuk.org.uk
Provides information on heart disease and its management by lifestyle
and drugs. Aims to help anyone at high risk of heart disease especially
families with inherited high cholesterol.
British Nutrition Foundation
Web: www.nutrition.org.uk
Their website provides healthy eating information
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Cardiovascular risk - assessment and management, Clinical Knowledge Summaries (2006)
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Risk estimation and the prevention of cardiovascular disease, SIGN (2007)
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© EMIS and PiP 2008 Updated: 20 Nov 2007
