5 Myths about the Coronary Calcium Score (CAC) | Tom Dayspring, MD
5 Myths about the Coronary Calcium Score (CAC) | Tom Dayspring, MD
The Coronary Calcium Score can be useful, but several myths surround it. We cover 5 misconceptions regarding the calcium score and how to interpret a calcium score to lower our heart disease risk.
Let’s talk calcium scan or calcium score. The calcium scan shows calcification in coronary arteries
myth: “CAC score of 0 means no plaque” a CAC score of 0 doesnt mean no plaque CAC doesnt measure plaque. Measures calcification. Calcification happens late in plaque formation process.
you can have a CAC of 0 and have soft plaque. Non calcified.
study: people with lots of plaque, 14% had CAC of zero. most young people with obstructive CAD had a CAC of zero
“diagnostic value of a CAC score of 0 small in the young”
advanced coronary disease: ~30% of heart attacks or death in people with CAC of zero
if CAC is zero odds are low you have obstructive CAD. but doesnt rule it out
even with a lot of plaque, calcification may not have developed CAC =0 is good news, it’s a marker of lower risk, but it doesn´t mean immunity
we can have plaque in other places besides coronaries CAC=0: 54% had plaque in the legs or the carotids
CAC of zero is desirable, but far from perfect
CAC=marker of advanced disease. CAC=0 may mean no plaque. or maybe there is. CAC doesnt rule that out
CAC=0 doesnt mean zero calcification. just detectable calcification scan picks up calcification above certain size, not small calcium spots. ~4% with CAC=0 had calcification
myth: CAC=0 means zero risk “LDLc or apoB is high but CAC=0 so I´m safe”
“score of zero does not imply risk is zero (heart attack, stroke etc) or zero atherosclerosis (plaque)”
“CAC of zero may provide false sense of security”
CAC of zero indicates low 5-10y risk value of CAC score depends on age
CAC=0 is the norm in young “CAC of zero in the young is normal, more power at older age. value of a CAC of zero increases with age”
myth: “if CAC goes up, i´ll make changes” calcification=advanced plaque real power is in preventing plaque
“Plaque calcification is a late event, not for pre-plaque detection (goal = prevent plaque)”
some methods measure soft plaque. angiography.
calcium not the cause of risk. marker of risk The more plaque, the more likely there’s calcification. calcification isn’t the problem. Calcification is part of the scarring of the artery, can make artery less likely to rupture
“plaque disruption and thrombosis not in calcified segments; calcium not the cause”
in general more calcium means higher risk, it´s a marker of more plaque and more advanced plaque, but something could increase calcium and not raise risk
statins can increase CAC but risk goes down. statins stabilize plaque, including calcification
CAC can refine risk. young with CAC that is NOT zero; older with a score of zero; borderline case with some risk factors but not clear if statin is appropriate, CAC can help decide
Disclaimer: The contents of this video are for informational purposes only and are not intended to be medical advice, diagnosis, or treatment, nor to replace medical care. The information presented herein is accurate and conforms to the available scientific evidence to the best of the author’s knowledge as of the time of posting. Always seek the advice of your physician or other qualified health provider with any questions regarding any medical condition. Never disregard professional medical advice or delay seeking it because of information contained in Nutrition Made Simple!.
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0:00 What is the calcium score? 0:53 Plaque with CAC=0 3:53 Calcification with CAC=0 4:32 CAC=0 and Risk 8:01 Calcium score and Age 9:33 Window of opportunity 10:47 More sensitive tests 12:17 Calcium is not the cause 13:32 Statins and Calcium 15:25 Take-aways and strategy 16:50 Additional Resources
Content
0 -> today we're talking about the calcium scan or
calcium score and we're going to cover five
5.28 -> super common myths about the calcium score. let
me know how many of these you find surprising,
10.08 -> I'm guessing for most people it's going to be most
of them. first of all, what is the calcium scan?
15.72 -> it's basically a CT scan, works by x-rays, you
lie down, they slide you into the scanner and it
22.14 -> basically takes an x-ray image of your chest and
it can show the calcification in your coronary
27.9 -> arteries, so the arteries feeding blood into your
heart muscle. in the end you get a calcium score,
33.54 -> which is basically a quantification of the amount
of calcification in your coronaries. it's a quick
39.42 -> test, takes about 10-15 minutes and it costs about
100 bucks ballpark, depending where you go. and
45.42 -> the calcium score can be useful, it can give us an
idea of how advanced the plaque in your arteries,
51.36 -> in your coronary arteries is. so the first myth
about the calcium scan is "I have a calcium score
58.26 -> of zero so that means I have no plaque". I see
even medical doctors sometimes saying this on
64.44 -> social media. that's a big misconception. a
calcium score of zero doesn't mean no plaque
70.32 -> because the calcium score doesn't measure
plaque per se, it measures calcification, and
76.2 -> calcification happens pretty late in the disease
process, in the plaque formation process, so it's
82.86 -> possible for me to have a calcium score of zero
and have what's called soft plaque, non-calcified
88.74 -> plaque, and actually in some cases you can have
plenty of it. here's a striking example, this
93.9 -> study looked at people who had lots of plaque, the
diameter of the coronary artery was reduced by 50
99.72 -> percent or more so they call that obstructive
coronary artery disease. out of those people,
105.36 -> 14 percent had a calcium score of zero but it
varied a lot depending on age, for older people,
113.34 -> 70 years old or above, only five percent of people
with that level of obstruction had a calcium score
120.36 -> of zero, but for young people, under 40, it was
58 percent, so most young people with obstructive
128.4 -> coronary artery disease, with a lot of plaque,
had a calcium score of zero. They concluded
133.98 -> that the diagnostic value of a calcium score of
zero was small in younger patients and greater
140.34 -> in older patients. they also followed 24 000 of
these people with a lot of plaque for four years
147.36 -> and about 30 percent of the heart attacks
or death that happened in that group
152.82 -> happened in people with a calcium score of zero.
don't get me wrong, if you have a calcium score
158.1 -> of zero the odds that you have obstructive
CAD, obstructive coronary artery disease,
163.38 -> that you have that much plaque, are very low,
it's in the single digits, it just doesn't rule
167.94 -> it out because in people who do have substantial
amounts of plaque, especially if they're younger,
172.56 -> calcification may not have had time to develop.
so a calcium score of zero is good news all
178.2 -> else held equal, it's a marker of lower risk in
most cases, it just doesn't guarantee immunity,
184.2 -> doesn't guarantee safety. that's the take-home
message. hope that makes sense. also, good to
190.14 -> remember we can have plaque in many other places
besides the coronaries. in this study they found
195.84 -> that out of people with a calcium score of zero,
54% had plaque in the legs or in the carotids
203.1 -> leading up to the brain. to put it succinctly,
a calcium score of zero is desirable but far
209.7 -> from perfect. so think of calcium as the tip of
the iceberg, it's a marker of advanced disease,
215.52 -> if you can see it it's a signal that there is a
lot more under the water, if it's not there, if
221.34 -> you can't see it, maybe there's nothing, but there
could be, there could even be a substantial amount
226.2 -> and it could even be growing fast, the calcium
score can't rule that out, especially at an early
232.74 -> stage. okay, second myth or misconception, a
calcium score of zero doesn't even mean that
238.92 -> there's zero calcification, it means no detectable
calcification. the scan picks up calcification
244.98 -> above a certain size but not smaller calcium
spots. in this study for example they found that
251.46 -> about four percent of people with a calcium score
of zero had some calcification that they could see
257.28 -> with more sensitive methods. okay but this is a
little academic, is there calcification or not,
261.72 -> even is there plaque or not, at the end of the
day what we care about is risk, what's my risk of
266.7 -> having a heart attack or a stroke, etc, right? the
rest is kind of details. so let's talk risk. the
273.42 -> third myth is that a calcium score of zero means
no risk. I see people saying this all the time,
278.52 -> "I have sky-high LDL-cholesterol or ApoB but my
calcium score is zero so I'm completely safe".
285.42 -> that's like saying my glucose is sky-high, I have
raging diabetes, but my toes aren't tingling yet,
291.6 -> I still have all 10 toes. that's good to know
but it's a very low bar and it doesn't guarantee
297.36 -> long-term health. these authors spell it out:
"clinicians should clearly communicate that a
303.48 -> score of zero does not imply that risk of an event
is zero (event means heart attack, stroke, etc) or
310.56 -> that the patient has zero atherosclerosis (so zero
plaque) and a calcium score of zero may provide a
318.6 -> false sense of security". the key mindset here is
time frame. short term versus long term. a calcium
326.04 -> score of zero indicates very low five to ten year
risk of an event like a heart attack. about one
332.82 -> percent chance over the next 10 years According to
some studies. okay, one percent chance of having
337.98 -> an event like a heart attack over the next 10
years, how relevant is that? depends. if I'm 80
344.46 -> or 90 years old and I have a low risk of a heart
attack in the next 10 years, that's good stuff,
351.18 -> but for example, I'm 45, if somebody tells me
that my risk over the next 10 years of having a
357.24 -> heart attack is very low, okay... um that's good
to know but I wasn't counting on it. I sure hope
365.28 -> not. what I really want to know is the next 30
or 40 years. it's explained here really clearly:
372.12 -> "preventive Cardiology has begun looking ahead
to Lifetime risk rather than 10 years for
379.02 -> calcium score and most risk calculators". now,
I recently discussed exactly this issue with Dr
385.62 -> Tom Dayspring. Tom is an internal medicine and
lipidology specialist and here's what he had to
391.86 -> say: so I think once calcium is there that's one
of these big indicators to me you are the person
398.64 -> I'm gonna blow ApoB and try and make it 40. but if
you come to me and your ApoB is whatever and you
405.72 -> say but I did a coronary calcium and it's normal
I would say okay, so here's the decision to make,
413.22 -> are you worried about what's going to happen
to you in the next 10 years or are you worried
417.12 -> what's going to happen to you at ages 70 80 90?
because if you are then we're going to start
423.42 -> maybe trying to lower your apob regardless of
your calcium score. but if you're just saying,
429.54 -> am I gonna have a heart attack in the next 10
years? and your CAC is zero, I would say no, and
435.3 -> therefore do I want to lower your ApoB? it only
depends if you're worried about longer term events
442.2 -> of atherosclerosis, then you're always going
to lower ApoB. so you get into that question,
447.3 -> so you know these people go on their ketotic diets
and send ApoB through the stratosphere, they go
453.48 -> get a coronary calcium and it's zero and they
say God thank God I don't have to do anything,
459.06 -> and you're playing that game again. at what point
is that ApoB going to harm you, or is your wishful
465.72 -> thinking gonna come true and it's never going to
harm you. and you can play that game in yourself,
470.16 -> you're the only one who can make that decision,
no matter what Tom Dayspring tells you or some
475.86 -> other advocate of ApoB is meaningless tells
you, you can decide yourself. so the key
481.68 -> takeaway here is that the value of the calcium
score hinges heavily on the age of the person.
488.46 -> oftentimes when I see someone on social media
saying my cholesterol is Sky High but I have
495.66 -> this calcium score of zero so I'm totally
relaxed, and by the way I'm 33 years old,
501.66 -> there's a misunderstanding there in terms of this
temporality and the long term. a calcium score of
506.64 -> zero is the norm in young to middle aged people.
for example in the cardia study among people 36 to
514.26 -> 42 years old, 90 percent had a calcium score of
zero and in the Mesa cohort for people a little
521.88 -> older, 45 to 54 years old, 73 percent had a
score of zero. so even up to mid 40s mid 50s,
529.5 -> most people have a calcium score of zero. and
that's for Western populations, right? where
536.28 -> cardiovascular disease is the number one cause
of death and it's incredibly common so it really
541.62 -> drives home this idea that a calcium score of
zero is what's expected, it's not a high bar
548.76 -> unless you're significantly older, if you're 70
or 80 or something like that then it starts to be
553.5 -> more reassuring. put in simple terms, a calcium
score of zero in a younger individual is normal
560.34 -> and expected but it has a lot more power at an
older age. just like fine wine, the value of a
568.26 -> calcium score of zero increases with age. I love
a good analogy and that's a pretty good one. okay,
573.72 -> fourth myth or misconception is "I'll just keep an
eye on my calcium score and if it shoots up then
581.88 -> I'll make some changes". remember, calcification
is a pretty late manifestation, it's a marker of
587.16 -> a pretty Advanced stage of the plaque, so it's
not a warning that the disease might progress,
593.1 -> It's a diagnosis that it already has. by
then you're basically doing damage control.
598.5 -> yes, there are still several tools to manage risk,
to reduce it, to prevent it from rising further,
605.28 -> pharmacological and lifestyle, but the real
bang for our buck is in preventing the plaque
611.1 -> from forming in the first place. in other words,
plaque calcification is a late event so it does
617.16 -> not accomplish early pre-plaque detection,
the goal being to prevent any plaque from
623.4 -> forming in the first place. now, of course the
amount of risk that I'm willing to tolerate
628.5 -> is a personal decision, it's for us to decide,
for each one of us to decide with our doctors,
634.02 -> just be aware that waiting for the score to go up
to then address risk factors is largely missing
640.14 -> the boat, the window of opportunity, so as long as
it's an educated decision and people are aware of
646.98 -> all the factors. there are more sensitive Imaging
methods that measure soft plaque as well, like
652.74 -> angiography for example, but it is more expensive
and more invasive, here's Tom going over it. you
659.88 -> also know Gil, that there is a much more intensive
Imaging procedure of the coronary arteries where
667.92 -> you just take a needle and you inject a dye, you
don't stick a catheter up in somebody's heart but
673.26 -> you inject a Dye that can show up in an x-ray,
and it's called CT angiography and that can show
681.42 -> plaque that is not yet calcified, it might show,
God, you got plaque, you got an 80% lesion there
687.96 -> but it's not calcified, maybe you got a lot of
smaller lesions that are not calcified but how do
693.72 -> you know they're not going to rupture tomorrow and
cause the thrombus that will occlude your artery?
697.74 -> so CTA would be a much better test to do except
it's 10 times more expensive, radiation exposure
706.44 -> in the wrong hands can be way more, in the right
hands it's not very much at all, so... but it's
712.8 -> super expensive, your insurance company might
not even cover a $100, $200 coronary calcium,
719.46 -> they're not going to cover a $1,500 CTA, so there
are other issues. if everybody in the world could
726.96 -> go to CTA at a certain age, fine, but that's never
going to happen of course. most of the time CTA is
734.64 -> done investigating people with chest pain. okay,
Fifth and last myth is that the calcification in
741.6 -> the artery is the cause of risk. calcifications
don't cause risk, they're a marker of risk,
746.88 -> they're an indicator of how advanced the disease
is. the more plaque someone has and the longer
752.04 -> they've had it the more likely that there's
calcification but the calcification itself is
756.48 -> not the problem, in fact it can sometimes be a
benefit, calcification is part of the scarring
763.02 -> process of the artery and it can actually make
it less likely to rupture and cause an event. in
768.6 -> fact plaque disruption and thrombosis tends not to
happen in calcified segments but in adjacent areas
776.58 -> so calcium is not actually the causal mediator,
it's not what causes the problem itself. I hope
784.44 -> this isn't too confusing, in general more
calcium is a signal of higher risk because
790.2 -> it's a marker of more plaque and more advanced
plaque underneath, just like the iceberg image,
797.04 -> but you could have something that raises calcium
and doesn't raise risk or even that lowers it,
803.34 -> right? a little odd, a little counterintuitive
maybe, but hopefully it makes sense now that we
808.5 -> understand the calcium is just a marker of disease
progression. the most poignant example of this are
814.62 -> statins, patients on a Statin sometimes see
an increase in their calcium score yet their
820.2 -> risk of an event is going down, that's because
statins have a plaque stabilization effect that
825.06 -> can involve calcification. here's Tom Dayspring
again explaining this much better than I ever
830.04 -> could. another thing pertaining to calcification
that confuses a lot of people is that statins can
835.68 -> increase calcification a little bit, right? indeed
there are studies showing that but in all trials
841.8 -> what do statins do? they reduce the incidence of
heart attacks. so statins you can make the case
846.84 -> are stabilizing existing plaque, they're scarring
it off so calcium appears but that is unlikely to
855.18 -> be a plaque that's going to rupture and induce a
clot that's going to send you to the CCU, so never
861.48 -> would you stop a Statin because a coronary calcium
score is increasing, you judge Statin efficacy not
868.86 -> by follow-up Imaging but by ApoB, that's what
tells you, is the Statin working or not? when
874.86 -> they first came out I had people who would run
and get them every year, I didn't advise it, but
878.82 -> cardiologists at that time did. it's a waste of
money and time because we know the Statin trials
884.94 -> show especially if your apoB is going down you're
going to have less heart attacks regardless of
889.44 -> your calcium score so right now I see people are
sort of recommending, well if you get a calcium
894.6 -> score, maybe you should repeat it in anywhere
from four to six years because you can maybe,
901.98 -> especially if it was zero to begin with, it's now
positive, but even say it was positive but it goes
908.58 -> up astronomically high, is that a worry? maybe
that would lead you then to a CTA or other better
915.84 -> evaluation of your coronary tree, but you don't
make Statin decisions per se only because of what
923.22 -> might be happening to a coronary calcium score. so
bottom line, a calcium score has prognostic value,
929.7 -> it can help to determine what someone's risk
level is, and it's especially relevant in three
935.64 -> situations: a young person with a score that is
not zero, that's a red flag. an older person with
942.42 -> a score of zero, that's reassuring. and the third
case is in borderline situations, maybe someone
949.26 -> who has some risk factors but it's not clear if
starting medication is the right move, or the
954.84 -> person would rather not, in those cases a calcium
scan can help tip the scales one way or another,
960 -> it could be a decent tiebreaker. here's Tom
Dayspring again: the guidelines currently suggest
965.58 -> if your LDL-cholesterol is above a certain level
or your ApoB is above a certain level you are in
972.66 -> a group that should consider Statin therapy, but
if you are totally anti-drug therapy, things that
979.92 -> would twist your arm and say, you better go on
a Statin, would be a positive coronary calcium
985.8 -> or the presence of lp(a) or the presence of
diabetes, then you always go on a Statin,
992.1 -> so that's how coronary calcium tests can be
used. any tests are great tests if you know
999.66 -> how to interpret them and use them and then
explain it to the patient what exactly, how
1004.94 -> it helps us solve maybe part of the problem, but
atherosclerosis is a long-term problem. a great
1011 -> resource that just came out recently is a one-page
primer on the calcium scan, it's Illustrated,
1016.4 -> written in a way that anybody can understand and
it covers all the basic ideas you need and it's
1020.9 -> completely free access so I'll link that in the
description below. hope this information helps,
1025.82 -> let me know your questions in the comments,
take care, I'll catch you next week, bye
