Coronary calcium score test and risk of heart attack (when to use and how to interpret)
Coronary calcium score test and risk of heart attack (when to use and how to interpret)
Coronary artery calcium score (CAC score) has emerged as an invaluable tool for predicting the future risk of a heart attack. There is mounting evidence that if your calcium score is high, the risk is high, and a calcium score of zero can be quite reassuring in the right person.
There are many caveats regarding this test. It can work as a double sword and, if not interpreted or ordered accurately, can cause harm.
When to order coronary calcium score?
How to interpret a positive result?
When should you repeat coronary calcium score, or should you ever repeat coronary calcium score?
Should you have a coronary angiogram if your coronary calcium score is high?
These are some typical questions that I have tried to answer in this video by presenting a real case. #coronaryarterydisease
Content
1.2 -> Today i'm presenting a case of a 60-year-old
man who presented with chest pain.
7.76 -> He presented in 2016 with quite a
non-cardiac sounding chest pain. He
17.68 -> is a non-smoker with no diabetes
he has well-controlled hypertension
22.4 -> his father had a myocardial infarction at 65 and
he was a non-smoker so this was quite a big shock
29.76 -> for the fam, for the family and he has been quite
concerned about this part of the family history.
35.68 -> He has a BMI of 26, blood pressure 130/70
mmHg, his exam was on remarkable
43.68 -> cholesterol 4.6 and LDL 3.4 which is 131 mg/dl. He is on telmisartan 40 mg daily.
57.2 -> To investigate his chest pain he
does an stress echocardiogram,
61.36 -> he exercises for nine and a
half minutes achieving 11 METs
65.6 -> this is a very good exercise tolerance, very
reassuring, there was absolutely no chest pain
72.96 -> or limiting dyspnea, there was no ischemic
features there were no ischemic features on
77.92 -> ECG or Echocardiogram. So based on these results we
could tell him your pain is not cardiac in origin.
86.16 -> He asks a question: he says "I don't want to end
up like my father having a heart attack at the
93.76 -> age of 65. Is this test enough to tell me my risk
is low or high or where I stand?". And of course the
102.96 -> answer is "NO". We tell him stress echocardiogram
here was only done, was only done to tell you your
110.56 -> "pain is from your heart or not" and that's it. To
calculate your risk we can use a risk calculator.
122.96 -> We plug his numbers into a calculator,
as you can see age, blood pressure, and
129.76 -> all the other elements and the calculator
comes up with 11% risk which is intermediately
137.28 -> elevated and optimal risk for this
person would have been 5.7 %
142.64 -> but we know that we have got another very
important test, which is calcium score
150.16 -> which can modify this risk quite significantly.
So he is sent to do a coronary calcium score
160.64 -> His coronary calcium score comes back
at 595 which is significantly elevated.
170.64 -> Now we recalculate his risk, incorporating
the calcium score we use a different
176.48 -> calculator, MESA calculator, which has a
coronary artery calcification as part of it.
182.16 -> Now we can see that his risk is 20% and not 11%
He is now "high risk". We have reclassified him
192.4 -> based on the results of coronary calcium score.
So now he knows that his risk is high he starts
200.08 -> Aspirin, he accepts statin, he changes his diet
and start a very vigorous regular exercise program.
211.68 -> One year later he presented to emergency
department with a very atypical chest
217.28 -> pain again. He ended up having a ct coronary
angiogram which surely counts him a score of 650
223.92 -> and moderate middle mid LAD and RCA disease, of
course his troponin and ECG were negative. He
230.24 -> had another stress test. he did exercise for
10 minutes on bruce protocol no ECG or Echo
237.12 -> evidence of ischemia. His LDL is 1.5 mmol/L. Again he was reassured that his pain is not
244.96 -> cardiac in origin and encouraged to continue
his medications and diet as well as exercise.
255.28 -> One year later in 2018, he returns for
review at this time his LDL is excellent at
262.4 -> 1.4 mmol/L, his blood pressure
excellent, he walks about 15 thousand
267.92 -> steps per day with no chest, pain he has lost about
8 kg by diet and exercise in two years
275.04 -> and basically he's doing very well but he
asks another question; he says "can I repeat
282.08 -> my calcium score to see what's happening and
where I stand?". Evidence is provided to him that
289.12 -> he really doesn't need to repeat the calcium
score we know he is high risk and he should just
294.56 -> take his medications and continue the good work.
Regardless he wants to do scan and he pays for
302.48 -> it and he does another calcium score which comes
back at 760. We see that initially it was 590.
314.72 -> He comes back quite anxious and stressed
with few questions; first he wants to know
320.8 -> more about coronary calcium score, what is
coronary calcium score and why we did it
328.24 -> calcium score only stratifies or reclassify
someone's future risk of CAD and "that
338.16 -> someone", this is the most important part "that
someone", should have low to intermediate risk
344.88 -> like our patient which had a risk of 11% which
is intermediate risk. So this person with low to
353.28 -> intermediate risk if they have high calcium
score they are reclassified to high risk
361.2 -> and by being reclassified to high risk their
medical therapy should be intensified, they
368 -> accept medication much easier and they
become more determined to change their
376.32 -> diet and start physical activity basically
"patient awareness" rises and that awareness
383.76 -> will make accepting change quite easier. So
here the most important part is that you do
391.92 -> not do a calcium score in a high-risk patient, the
patients should be low to intermediate risk. I will
400.08 -> try to explain with a different case as why you
don't do a calcium score in a high-risk patient.
410.08 -> Just for a moment forget about the original
patient, i'm just showing and presenting a very
415.92 -> quick case as why we do not do calcium score in
high-risk patients. So this is a 52 year old 56
425.04 -> year-old man with well-controlled type 2 diabetes
for about 20 years. He does not smoke nor has
431.92 -> hypertension but he has got a very significant
family history: one brother at 52 with bypass
438 -> one brother fatal myocardial infarction at 58
and father fatal myocardial infarction at 67,
445.2 -> all of them were non-smokers. He is not on
statin and why? Someone actually told him that
452.64 -> hey your cholesterol is borderline let's do
a calcium score and if it is zero you don't
458.08 -> really need a statin and that's why he's not
on statin. For some reason he ended up having
464.48 -> a ct coronary angiogram the reason that's beside
the point that why he has ct coronary angiogram
469.76 -> but let's have a look at his coronary arteries.
These are his coronary arteries: RCA, Lcx and LAD.
479.92 -> we can see that there is absolutely no calcium
in this artery so his calcium score is zero but
486.8 -> let's concentrate on his LAD for a moment. Let's
concentrate here on LAD. If i zoom on this section
497.12 -> we can see that we have got two big Plaques on
this side of the artery wall. These areas these
505.76 -> are soft plaques means there is no calcium in
them, they have got a lipid core so it is full of
512.4 -> lipid and foam cells, these are high risk
plaques they are angry and they have got a thin
520.24 -> fibrous cap which is vulnerable to rupture, causing
acute myocardial infarction and blockage of the
528.64 -> artery. So you can see that there is no calcium
in them so the calcium score comes back at zero
536 -> and this is quite misleading and a calcium score
of zero deprives this person from a life-saving
544.08 -> therapy which is a statin which is plaque
modifying agent. Let's go back to our original case
552.72 -> which was the 60-year-old man with intermediate-risk and high calcium score. His first question was
557.84 -> that he wanted to know about calcium score and why
it was done his next question is that do i need an
565.12 -> invasive coronary angiogram? At the end of the day
my calcium score is high. It's very important to
572.96 -> know that calcium score should not be used as
a guide to decide about coronary intervention.
581.36 -> Basically when calcium score testing was
started about 20 years ago, many many cases
588.8 -> were sent for coronary intervention or
angioplasty based on high calcium scores
594.56 -> and that's why after a while, for many years
this test was not being used till around 2010.
603.2 -> The reason is that we do coronary calcium
score in people who have "no symptoms" or
610.64 -> someone who we have proved, based on the
functional test, that their test that the
616.08 -> chest pain is not cardiac in origin and if
you are that person you don't need coronary
621.6 -> angiogram or angioplasty, so no matter what
your calcium score is, a calcium score should
628.96 -> not be used as a guide for coronary angiogram or
angioplasty. it just means that the risk is high.
639.92 -> And his next question and last one is that
"should I stop my statin? it seems that it's it's
646.56 -> not working and my calcium score is rising", and
let's see why. It is proven that statins promote
654.4 -> vascular calcification in one study in 2015
they reported an annual calcium score increase
664 -> of about 30%at the age of 50 and 21% at
the age of 70, when they started statin therapy
675.76 -> again another study in 2015 showed two
mechanisms as how their statins work.
683.76 -> they showed that number one, statins reduce the
plaque volume, so basically they shrink the plaque
690.24 -> they make it a bit smaller and denser and, number
two, which is the more important one they change
697.52 -> the composition of the plaque, so they suck the
lipid core out and replace it by fibrous tissue
707.84 -> plus calcium, hence the calcium score goes up
after a starting statin therapy so imagine you
716.08 -> have got an artery in this artery you have got
a plaque, this plaque has got a lipid core
725.04 -> which is soft and a thin fibrous cap, this
is a soft plaque and very vulnerable to
733.6 -> rupture, causing myocardial infarction. When
you start statin therapy what happens
740.32 -> so number one the plaque becomes a bit
smaller you can see there so "volume reduction",
747.76 -> and number two the composition has changed, now
the lipid core is nearly gone and you have got
754.8 -> fibrous tissue and calcium, this is a calcified
and "stable plaque", that's why statins are called
766.48 -> "plaque-modifying treatments", plaque modifying
treatments so from a plaque which looked like this
775.92 -> soft and angry with a lipid core, we change
we change it to a plaque which look which looks
782.64 -> like this you have got calcium and is stable and
this plaque can stay there for many years without
790.48 -> causing any problem. So although calcium score is
a very good test, repeating calcium score after
800.72 -> starting statin therapy, can only cause anxiety,
confusion without adding any useful information
809.76 -> and "it is not recommended". To recap the main points
of the presentation, calcium score is done only and
820.48 -> only to "stratify" someone's future risk if they
are low to intermediate risk and not high risk.
830.24 -> Calcium scores should not be used to decide
about coronary intervention or angiogram.
839.6 -> Calcium does not equal plaque. Plaques
can either be calcified or non-calcified
846 -> and like in other example if
you have non-calcified plaques
850.16 -> your calcium score can be zero
but you can be very high risk.
855.44 -> and the last point repeating a positive calcium
score, is not recommended and it can cause anxiety,
863.12 -> confusion without adding any useful information. Thank
you very much for your attention. I hope you have
870.4 -> enjoyed the presentation please like and subscribe
and hope to see you for the next presentation.
Source: https://www.youtube.com/watch?v=q-hOevyERfc