in 2005 on a weekend day as I was
driving to work there was a fun run in
progress I noticed there was an
ambulance and a commotion being a doctor
in fact on the cardiologist I thought
I'd stop and see if I could offer
assistance it turns out a man one of the
participants of the Fun Run had dropped
dead from a heart attack I was by the
roadside there was another doctor and a
nurse who are participants of the Fun
Run they'd also stopped to give
assistance and with the two ambulance
officers we worked on this man we got
his heart beating again we got him in
the back of the ambulance into the local
hospital where he received the
life-saving stent to the artery again
the front of his heart his story was so
good in fact that it made the front page
of the local newspaper just a couple of
days later and he can't see it clearly
but there is a reference there to the
cardiologist who offered assistance now
modesty prevents one from indulging too
much but opportunities like this rarely
come up so I bought a copy of the paper
and took it to work and it only took a
moment for one of my secretaries to
point out I'd seen the very same man
some eighteen months earlier as a
patient well what I want to tell you is
who dr. Sauer laughing slap my leg and
said well what a coincidence because
everything I've heard about TED talks
tells me they should be humor but that's
not true
actually I didn't laugh I didn't laugh
at all I was immediately struck by the
gravity of the situation I had not seen
that event coming I was shocked I went
back and looked at my notes to see what
had happened and it turned out I'd done
everything right for this man according
to local and international guidelines I
put him through a treadmill test and
he'd passed with flying colors I put him
through a risk calculator and found that
his risk was low in fact you've got a
green thermometer and I reassured him
and sent him on his merry way
I only be standing over his dead body
some eighteen months later
clearly something is wrong here and what
I'd like to do for the remainder of my
talk is share with you how my assessment
in 2003 just didn't provide what this
man needed and how we can do better well
let's start with stress testing the
premise is really straightforward if we
take a piece of artery that goes to a
piece of heart muscle blood goes down
that artery if we restrict that blood
flow for some reason the muscle doesn't
get enough blood it's under stress and
strain and we pick that up on the dots
that we monitor people with so
straightforward when we think about what
goes on in arteries plaque can build up
in arteries and when it's early on
plaque doesn't limit flow at all so the
blood goes down freely no restriction
these people would be completely
asymptomatic so they can work hard blood
flows down no symptom but as plot
progresses it can get to a point where
its flow limiting and these people when
they increase the workload of the heart
need more blood not enough blood gets
there they may get chest pain and
shortness of breath we also picked that
up on our ECG on our stress test if we
stopped to look at what that plaque is
made up of both then non-flow limiting
and flow limiting clock it turns out
they're actually cut from the same cloth
no surprise and the concept is a bunch
of cholesterol sitting in the artery
wall covered by a fibrous cap that
separates that from the contents of the
blood so when a heart attack occurs that
fibrous cap is disrupted for some reason
and that allows mixing of the contents
of the lumen with the cholesterol plaque
and that's not meant to happen in a clot
forms that clot can form suddenly and
block the artery completely and you have
a heart attack well the interesting
thing about all this is when we look in
more detail at heart attacks it turns
out about 60% of all heart attacks occur
on flow limiting Clark these are people
who would have had some clue beforehand
maybe shortness of breath or chest pain
on exertion
but here's the scary thing 40% of all
heart attacks occur on plaque that has
non flow limiting up until the moment
that the plaque ruptures think of our
fun runner he put his sand shoes on that
morning expecting to run ten kilometers
because he felt fine so now that we
understand heart attack because we're
all we've just gone through second-year
medicine and we're right across it what
we're going to do is think about how
good our stress test is for predicting
heart attacks so let's start with our
patients who have got narrowed arteries
their flow limiting like a flow limiting
clock and they should be symptomatic so
we put them on a treadmill test it turns
out the treadmill tests are not perfect
tests that we don't have very few
perfect tests a treadmill test will pick
up about 85% of what's actually there
it's a make sense so if we pick up 85
percent of the 60 percent of heart
attacks on can do the math to check me
but it's 51 percent now we could toss a
coin and get a 50 percent pick up right
are we impressed with stress testing for
predicting heart attack I don't think so
okay well let's look at our asymptomatic
patients our people who have non flow
limiting plug we put them through a
treadmill test there's no limitation to
flow how many heart attacks could we
potentially pick up or predict zero
correct so what I really want to get
across to you guys is that narrowed
arteries don't kill you
arteries that suddenly block do so when
we think about our stress test it's good
for correlating symptoms of chest pain
and shortness of breath was strain on
the heart so it's a diagnostic tool it's
good for that it's good for telling us
if you're fit so lots of patients want
to know how far they went is that good
compared to the guy you just had through
but it's not very good for telling us
the health of the arteries and it's just
no good for predicting heart attack
let's look at risk calculators
this is a standard sort of risk
calculator when I saw the fun runner
back in 2003 I said something like well
given your male 50-something blood
pressures well controlled on blood
pressure tablets etc etc cholesterol is
okay nonsmoker
your risk of a heart attack is only 6%
the next five years you'll be fine but
I've misrepresented that data and what I
should have said to this man is fun
runner based on your characteristics
what this risk calculator is telling me
is if I take 100 men with the same
characteristics and follow those 100 men
for five years six of them will have a
heart attack or stroke I just don't know
if you're one of the six or one of the
94 because back in 2003 I really didn't
have a good grasp of the difference
between population based probability
which is the rate of event in the
population which is given to us by the
risk calculator this individual
actuality because the individual is
either going to have an event 100
percent think fun run or not have us an
event zero percent let me introduce you
to the 50 year old mile 100 voice choir
and on embarassed to say that the choir
master had has a better handle on this
concept than I did back in 2003 he says
okay guys I've spoken to the doc and he
says about six of you I'll have a heart
attack in the next five years could I
just ask that it's not all the tenors
but what if we could be more precise
what if we could take a 50 year old male
100 voice choir and do something put
them through a scan or a screen or
figure out who in that group is actually
at high risk well it turns out that
pluck leaves a footprint in the artery
it leaves calcium so where cholesterol
building up in arteries we see the
footprint of the tiger and as fate would
have it we have a machine that allows us
to scan for that calcium it's a CT
scanner
and it means that we can then look at
people's individual hearts we can look
inside on the left-hand side a
healthy-looking heart on the right-hand
side clearly a problem once we've got
this information we can start to really
break down a hundred Voice Choir into
the true high-risk people the true
lowest people and those in between and
why is that important because if we can
find the true high risk people before
they have a heart attack we can put in
place treatment that can actually
prevent the heart attack anyone think
that's a good idea
hear me - so the reason I'm up here is
that even though this technology is
broadly available it's broadly
underutilized and many many of my
colleagues still are happy to treadmill
test and put people through risk
calculators to evaluate their risk of a
heart attack and that's in spite of
heart disease being the number one
killer of men and women in the Western
world accounting for over 9 million
people globally in America six hundred
and forty thousand people per annum it's
one in every four deaths and since I
started talking 10 to 15 people who have
had a heart attack no one in this room
I'm pleased to say but the statistic
that is most staggering for me is this
one two in ten of those heart attacks
20% are occurring in people 65 years of
age or under these are not people ready
to die piece of people who still had
plenty of life to live plenty of life to
give I can think of no embedded to offer
some comments at this stage hi my name
is Gary in 2005 during the city to
casino fan
I had a heart attack remarkably I was
resuscitated and and survived my three
children were almost orphaned that day I
had no idea before the event that I was
at high risk fortunately I'm still alive
but I know others who are really so
lucky there was no way to predict what
happened to me
but times have changed do you know your
real risk of heart attack so most
remarkably Gary still talks to me even
though I killed him once but more
important than that that day he may have
ended up as a statistic a number on a
piece of paper nothing more but what I
want you to get is here's a man with
three children heart attack destroys
families
it takes away loved ones it devastates
communities and we can prevent it it is
time for us to stop crystal balling it
is time for us to look to a better idea
in the future we can be more precise
about cardiovascular risk we can
identify people we can find people's
real risk of heart attack find those at
high risk and make a difference my hope
today is to educate inform and hopefully
even empower the people here so that you
ask the right questions so you get the
best health care so you don't die from a
heart attack if you've got someone you
know or love and you think this
information is valuable for them share
it please if by chance you see this on a
video I would flatter myself if you did
please share it this is so important
because we can prevent heart attack and
we should I appreciate your attention I
genuinely wish you all good health and
please don't die from a heart attack
[Applause]