Download What causes a heart attack?

What causes a heart attack?
A blockage starts to develop on the artery wall.
It becomes harder for blood to flow through the
artery.
Growing blockage
Blood flow
blocked
Smokers with version A of the gene have more
sticky cholesterol and so get blockages in their
arteries faster. This increases their chances of
getting heart disease.
If you’d like more
information, your
GP will be happy
to
discuss
this
leaflet with you
What’s the
link between
smoking, genes
and heart
disease?
Heart is
starved
of blood
Blood flow
completely
blocked
Blood clot
Heart attacks occur when the artery is
completely blocked. This is usually caused by a
blood clot forming at the site of the narrowing
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However, if you quit smoking, you will stop
damaging the walls of the arteries in your heart.
You’ll no longer have sticky cholesterol due to
the chemicals in smoke.
Your risk of getting heart disease will decrease
to that of a non-smoker over time
Information from your GP
Will you get heart
disease?
How does this gene work?
Chemicals from smoke damage the walls of blood
vessels in your heart called arteries.
A new test will let smokers know if they’ve
got a particularly high risk of getting heart
disease. The test is for different versions of
a gene called HD1.
The gene has two versions. A person can
have either version A or version B.
artery
Blood Flow
People who have version A have less protection
from smoke damage and so have more sticky
cholesterol
Chemical made
by version A
S
M
O
K
E
What’s this got to do with heart disease?
Researchers at the University of London
tracked the health of 3052 people over
eight years.
Meanwhile, smoking also damages cholesterol in
the blood, making it stickier.
People who have version B have a little more
protection from smoke damage and so less
sticky cholesterol.
In general, smokers were roughly twice as
likely to get heart disease as non-smokers.
Chemical made
by version B
However, smokers’ risk of getting heart
disease depended on which version of the
HD1 gene they had
• Smokers who had version A of the gene
were three times more likely to get heart
disease than non-smokers
• Smokers who had version B of the HD1
gene were twice as likely to get heart
disease as non-smokers
No matter which version of the gene they
had, over the course of the study, smokers
who quit smoking reduced their risk of
getting heart disease to roughly that of nonsmokers.
Ordinary
cholesterol
Sticky
cholesterol
The HD1 gene makes a chemical which helps stop
cigarette smoke damaging cholesterol.
The chemical made by version A of the gene isn’t
very good at its job.
The chemical made by version B of the gene is
better at its job
S
M
O
K
E
This sticky cholesterol enters the hole on the
artery wall caused by smoking.