Coronary Calcium Testing: Is it Safe?  – FORD BREWER MD MPH

Coronary Calcium Testing: Is it Safe? – FORD BREWER MD MPH


When John published his video on decreasing his coronary calcium score I
expected to get some criticism as his doc I didn’t tell him that beforehand in
fact I encouraged him to to do the video here’s why here’s why I encouraged him
obviously to get the kind of impact to it’s newsworthy to decrease the coronary
calcium score we’ll talk about that in a few minutes
very unusual I’ve seen it maybe twice in my career and it was very much
associated with the changes he made in his lifestyle 42 pound weight loss decreasing recorded blood sugars as high
as 300 down to keeping them routinely below a hundred so again people say you
don’t you don’t get a decrease in coronary calcium well he did and I’ve
seen it and again it was associated with what he accomplished from his lifestyle
but back to my first comment why did I expect to get criticized as his doc a
couple of things number one serial calcium scans I don’t know
anybody that recommends serial calcium scans although you can do them and you
saw in John’s case there was a significant significant correlation
usually you don’t see a correlation and that is a step wise increase in calcium
as you get a stepwise increase in imply but that wasn’t the reason well that was
one of the reasons I expected to get criticized and didn’t hear was another
reason maybe a bigger one and that is also the reason why a lot of people
don’t reckon recommend coronary calcium screening on a against screening basis
and that has to do with safety there’s a perception out there that there is
significant risk associated with radiation from
coronary calcium scores it’s a CT technology and there is
significant radiation but we’re gonna kind of cover a little bit more detail
on it and make the point that it’s not even in the same ballpark why am i
showing a picture of the Cincinnati Reds stadium garmi stadium again when we’re
talking about risk of coronary calcium radiation compared to risk of heart
attack and stroke if you have coronary calcium or if you have plaque and you
don’t know it no comparison they’re not in the same ballpark well I’m sure
they’re quite a few out there who are saying well Brewer wait a minute you
said there is some risk and it’s significant I want to know more okay
we’ll tell you a little bit more this article came from the Journal of MRI
magnetic resonance imaging and the excuse me
that’s the ramipril cough there the the title is self-explanatory imaging
strategies to reduce the risk of radiation in CT studies including
selective substitution and it mentions MRI in the title but I’m not gonna get
that deep in this article I will give those of you who have an interest as
usual I’ll give you the reference below the video in the some of the text
explanation but they also mentioned multiple times in this article
substitution with ultrasound and that is exactly what CIMT technology is I will
step away from the risk question for just a second
and compare the screening technologies the most common screening technology
you’ll see out there with standardized medicine is stress tests and I run away –
I get anaphylactic I get an allergic reaction to talking about ordering a
stress test I have ordered a few again three or four not that many stress test
that has way too many false negatives you remember Tim Russert he’s the one
that he was the news guy that had a normal stress test in March of when was
it 2008 and then had a fatal mi in June
so unfortunately stress negative stress tests give away too many people a false
sense of security so from that perspective I personally feel that
they’re dangerous you get far fewer false negatives with coronary artery
calcium score but again with coronary artery calcium score we’ve got this
radiation issue and you’ve got a major issue with with they don’t correlate so
well with increase in plaque you know the serial type of of correlation you
can’t judge on an ongoing basis so I’ve done a few of those and I do those in
cases like with John where you had you had very confusing CIMT picture and in
John’s case it was due to the increasing sensitivity of the CI MT creating a
false impression that there was an increase in plaque when we both doubted
that severely and Todd again Todd Eldredge came on and gave us some good
guidance in that area and agreed very strongly that there was not an increase
in plaque so that’s the digression and again those
of you who are interested in this question of just how much radiation how
much risk is associated with CT technology well
this article comes right out of the blocks giving you some good numbers
the FDA estimate for a CT dose of ten millisieverts let’s not get- try to
quantify that but let’s go to the next part associated with an increased chance
of developing fatal cancer for approximately one in 2,000 patients over
a lifetime. lifetime risk needs to be quantified and compared here as well
when you’re talking about lifetime risk in terms of radiation we’re talking
about infants five-year-olds all ages in the lifetime for an impotent and the
expected lifetime for an infant in five and ten year old twenty year old is
obviously much greater than the expected lifetime of a someone with heart attack
and stroke risk in fact we’ll talk about Cafes-Caves study a little bit later and
compare the risk and life expectancy for folks with with plaque and we’ll see we
don’t measure risk in terms of lifetime there we measure it over a 10-year
period and we’re also again I’ll bottom-line it here for those of you who
just want to hear it and move on to the next video we’re talking about risk of
like four and ten eight and ten that’s untreated if you don’t if you have
plaque and significant plak plak up to the area to the level of obstructing
flow is an 8 in 10 probability of having a heart attack or stroke over a 10 year
period again I’m going to the bottom line and giving a giving away the info
for later a spoiler again pardon the digression I’ll get back to
helping understand the the risk and putting risk associated with CT in
perspective again we’re talking about fatal cancer in one in 2000 lifetime
we’re not talking about immediate and we’re not talking about over a ten-year
period either is I just clarified cancer risk in and of itself one in a thousand
lifetime risk so again these rick CT radiation is not not in totally
innocuous not and totally say not totally safe like CIMT and ultrasound
technology is for those of you who’d like to get a little bit deeper
comparison they start out in terms of comparison comparisons with atomic bomb
survivors atomic bomb testing folks that were in the same area I think it was
Solomon Islands whatever Islands it was there was a large health cohort where
they studied these folks I mean these folks had skin burns they had cataracts
they had immediate surface body surface problems you don’t see that these days
and that’s not really associated with CT scanning now as many of you may know
that has been associated with radiation therapy so again when you start getting
into radiation therapy you’re getting back into a whole new area of risk we’re
not talking about those levels of risk with CT we’re talking about again one in
a thousand one and two thousand lifetime increased risk of cancer I’m going to
jump over to another comparison point and that has to do with chest x-ray
people get very concerned about chest x-rays and say well you know I don’t
want to have a chest x-ray I don’t recommend I
don’t use chest x-rays very often either gosh maybe ten or twenty one of my major
associations with chest x-rays was that as an epidemiologist public health
prevention guy one of my major jobs was getting rid of
the old habit of routine screening chest x-rays so I had his chest x-ray compared
to CT about a hundred to a thousand chest x-rays is equivalent to the
radiation in one CT so again see T’s not innocuous it’s not a totally risk-free technology I say all of that and I think
the people are hearing this and they’re never going to get a CT I would ask you
please watch the the the movie Widowmaker it’s very good it’s actually
encouraging the use of coronary calcium I would say look if it’s going to take a
coronary calcium score to get you focused on your heart attack and stroke
risk you’re better off doing a coronary calcium score as I’ve shown multiple
times and we’ll continue to talk about during discussions of science and a
mini-series on screening programs for heart attack and stroke risk you’ll see
that I clearly recommend CI MT I had a great discussion with Todd Eldredge
who’s an epidemiologist that got very passionate about CIMT screening for
heart attack and stroke that’s in another one of our videos we go into
depth on the problems and frustrations associated with getting CIMT out there this study is the Café’s -Cave study and
again it helps us begin to put or continue to put risk
in perspective this is an old video I mean an old image from Brad Bale and Amy
Doneen – they they taught me a lot of the focus that we’re talking about with
CIMT some of the other technologies that that we’re looking at and they have
a great training program for docs dentists and a lot of non-medical people
nutritionists a lot of other folks who have gone to their courses very very
good course and a very good book they’ve written beat the heart attack gene now
this is the Café’s – Cave study as you see in the title up here this was like maybe
the definitive study in helping us understand the value of CIMt this was
using CIMt carotid femoral ultrasound screening and cardiovascular events in
low risk subjects now here we’ve got this term this word risk again in this
title of what did risk mean did it mean that had a coronary calcium score and it
was low no that did not mean that did it mean that they’d already seen low risk
own ultrasound see IMT screening know this they had they had low risk is
defined by Framingham Framingham is all demographic and history type stuff are
you a smoker what is your age what is your gender what is your BMI again BMI hopefully
will be replaced by relative fat mass soon but again at that time we were
looking at BMI they took people ten thousand adults they actually had 13,000
subjects but ten thousand adult subjects went a full 10 year period they did
CIMT screening on these folks and all ten thousand people were people like me five
ten years ago who you would say you’re an adult you’ve had
you’ve got some association with being a male and age but really know no other
significant risk factors well they did find significant risk using CIMT
screening now let me give you some of the numbers at ten years there were ten
events for people with class one that was none that was again a a fairly low
number that was the folks that they would agree yes they’re low risk anyone
events in class two for nine hundred and thirty subjects but here’s where you got
folks like me I had a plaque if you look at arterial age 72 years old even though
I was 57 and everybody would have said you’re a low risk individual I would
have fit in the Café’s Cave study I would have gotten let into it I would
have been in this class 3 – there were 611 subjects out of the 10,000 and there
were thirty two hundred and thirty nine events in ten years in other words about
40 percent these individuals had a heart attack or stroke within a ten year
period so you begin to see there those of us who are out there who would have
been labeled very low risk and said you know I don’t have a problem they also
added that low risk pool they found there were what four hundred and seventy
subjects who had plaque to the extent that it obstructed blood flow if you had
that much plaque even though by Framingham you had very low risk
you had an 81% probability of having a heart attack or stroke over the next ten
years so again this cafes cave study is a critical it’s a landmark study and it makes it very very clear we’ve got an a very safe
technology with CIMT I’m not saying it doesn’t have problems it does but it’s a
safe technology which is extremely effective and taking people that thought
they had low risk and finding a significant population what was it what
up to 40 percent of them had risk that they just did not know about so again we
talked a lot about risk we talked a lot about screening technologies for heart
attack and stroke I if you’ve made it this far in the video I appreciate your
interest

23 thoughts on “Coronary Calcium Testing: Is it Safe? – FORD BREWER MD MPH”

  1. A Coronary Calcium score CT Scan is equivalent to 1000 chests x-rays or more AT ONE TIME, which makes it more dangerous. Ionizing radiation is like whiskey, you can have one shot a day for months with no effect but if you drink a half gallon in 1 minute you will die.

    50 chest x-rays equal 1mS. Coronary Calcium CT Scans are generally 20-40 mS depending on the scanner, the software, the size of the patient, the technologist performing the scan and the factors (MaS/KVP) that is used on the scan.

    I used to do those scans beginning in 2006 with Siemens 64 slice scanner. I am a registered X-Ray, CT Scan/MRI technologist. I've been retired for a few years. The incidence of getting cancer from just one scan is 1 in 1000. It is a LOT of ionizing radiation AND limited to the lower chest upper abdominal area which is the hardest to penetrate because of the fluid in the upper abdomen. Heavier people can get 2-4 times more than the average patient because the fluid raises the diaphrams higher while lying supine for the scan.

    I wouldn't have Coronary Calcium CT Scan today. I'd prefer a CIMT. Live like your Calcium Score is 1000.

  2. http://www.xrayrisk.com/calculator/calculator-normal-studies.php?id=20 You can estimate the mSv or ask the technician for the DLP number and that will give you an accurate idea about the amount of radiation used. My additional cancer risk was 1 in 8039 or .012440%. My lifetime cancer risk is 44.9% without the scan. I'm 36 and my CAC score was 123. Getting the scan was the best decision I've made for my health.

  3. CIMT is better in many ways than the CAC. CIMT is safer from the standpoint of having no ionizing radiation.

    CAC or CIMT then a stress test and nuclear imaging…. at 70, not too worried about the radiation. I'm worried about the coronary artery disease progressing and sending me to the cath lab. Avoid the radiation by all means.

  4. My wife had CIMT and was negative for any plagues. We work out together and eat the same diet. Her family history is negative for stokes or heart attack. Mine is positive, including a paternal grandfather who died at 53 of a heart attack. My wife had three CT scans for incidental reasons. Her Abdominal and chest CTs were also negative for any calcifications in the coronary arteries. She went over these findings with her cardiologist.

    My CAC was bad but I did well on the stress test. In the left anterior descending coronary artery, I have about 50 percent occlusion. I have no plans for interval tests. My cardiologist said regression of plaques as measured by angiograms is in the eye of the beholder. He does not believe Dean Ornish really proved anything, although they know each other.

    I have given up on regression of my plaques. But the CIMT might show regression. I would not repeat the CAC just to try to document coronary artery plaque regression. My wife had a lifetime of ionizing radiation because of incidental findings on the lungs and kidney. Ultrasound is harmless, however. I also note what John said but I have not done the math. I threw out my Biophysics for Dummies. He is probably correct that a CAC is not even close to a regular abdominal of chest CT.

  5. I had a CIMT test (they call it carotid triplex here in Greece) about a year ago and the results I got were not clear as to the condition of my arteries. As you explain in a recent video the way thickness is measured is not that consistent and replicable which adds to the difficulty in assessing risk based on this test. This led me to follow it with a calcium score test which gave me a much clearer picture of the condition of my coronary arteries and led me to a series of major lifestyle changes similar to those that John describes. I am not sure that I would have gone so far along this path were not for my Calcium score of 409. These changes have led to dramatic decreases in all the inflammatory markers suggested in your videos to what Bredesen considers optimal (with the exception of homocysteine at 10 from 15) which are also n presented in Bale and Doneen's book and your videos. I consider the drop in my fasting insulin to levels below 5 the most significant accomplishment of this effort. What surprised me the most was the negative reaction to the point of ridicule I encountered when I consulted with cardiologists over my having had the Calcium Test. They told me that it was very common for men my age (60 at the time) who had smoked in the past to have calcium in their artery walls and that it was just a sign of aging. It can be tricky to find the right doctors without falling into the trap of finding one who will only tell you what you want to hear as to confirm your biases. I wondered why you had not breached the subject of calcium scoring till this day since it seems such a powerful tool for a diagnostician. I am debating how to retest (speaking of imaging tests) as the 1 year mark since my lifestlyle changes is fast approaching: other than the cost I see no reason not to repeat my CIMT even though I am not sure what conclusions I may reach from the results. What you mentioned about John's CIMT results has only increased my skepticism. As far as calcium scoring is concerned I highly appreciate your exposition of the risks from radiation yet my curiosity will play a significant role in my decision when to remeasure my calcium score if at all. Your approach to present the data without explicitly advocating a course of action is highly responsible and commendable and in keeping with the physician's role as a consultant on health matters to the patient who seeks to make the best-informed decisions.

  6. Heart disease runs in my family. 9 months ago I had my first CAC scan. In my mid-40s I got a result of over 1000. Stress test showed abnormal flow. I had two arteries both blocked 95%. Was the plaque stable? I couldn’t really go on with that hanging over my head. I ended up getting angioplasty.

  7. I don't remember hearing that you had a CAC score done as your initial CIMT test was the wake-up call to make some changes. Do you use an initial CAC score evaluation as part of your practice for those over a certain age or those with high risk factors? I have heard recommendations of getting one CAC score done at age 40-50, make lifestyle adjustments and then wait five years for another one.

    I hope that CIMT tests become more common. I had to push my ex-doctor to get a CAC score done because I was a low-risk patient (until he saw the score). I next found out about the value of a CIMT test. When I went in to ask my ex-doctor about a CIMT test, his head nurse didn't know what a CIMT test was as I had to explain it to her. I eventually found a place to get a CIMT test and spent time trying to understand the nuances of what it meant.

    I am going to wait three years or more for a second CIMT test as I am not sure that it will be meaningful to have a lot done. I think in the end I either make the necessary changes in my lifestyle or I don't. I think standard blood tests can provide an interim clue as to what is going on once a person gets a good baseline (e.g. advanced lipid test, CAC score and CIMT test).

  8. Thanks for the interesting vid Dr. Brewer! The vid clearly triggered a couple of questions to me: 
    – You mentioned John realised a regression of his plaque through lifestyle changes, i.e. loosing 42 pound and keeping his insuline-level low (largely accomplished through a HFLC-diet as I believe). If one has no insuline issue at all and a body fat% of less than 16%, do you still believe a HFLC-diet can be effective in potentially reducing plaque or would in this case other changes potentially be more effective (e.g taking Statin)?
    – Is there somewhere information available on how the CAC-score relates to the percentage of occlusion within an artery (e.g a CAC-score of 200 in one artery means 25% occlusion and a CAC-score of 400 in one artery means 50% occlusion, etc? Thanks a lot!

  9. Good informative video..I believe John L gave a very good analysis and explanation around Radiation dose. To me knowing the disease and moving forward to combat is more important. The scary part is that plaque calcium progression is 30& YOY.. 1st order of business is to decelerate then stop progression. I’m more concerned with unstable hot plaque rupture than stable calcified plaque.. I see value in a follow up CT heart scan to see status of progression… Based on stress test, no indication of impaired blood flow in heart… hopefully my plan is reducing the root cause, inflammation. Great videos

  10. Radiation exposure gets tricky. While this may not harm you on its own another medically needed exposure in a short period of time becomes the issue. We never know when we will be injured in a car accident. I used to work with industrial radiation and cannot recall all the rules or levels of exposure. I am curious what the recomended frequency is for this procedure ?

    It seems K2 & Magnesium control calcium levels in not good places of our bodies. It seems we traditionally made our K2 by having a healthy gut. Both of these nutrients come from eating Green Vegetables and having a healthy gut or via supplementation.   I can eat a pound of green vegetables each day with the addition of fat & salt. Eating fermenting cabbage, vinegar, etc. so my gut makes K2 and other happy things is also easy.  

    We as humans have been fed a growing amount of 'Purina Human Chow' for 100 years because of a successful government lobby and watched heart disease increase.

  11. My 2 cents (as a patient) – I believe the CT risk stats are based on the linear no-threshold model for radiation risk, which assumes there is no dose without risk, and not on actual data. On the other hand there is data to suggest that low doses may be hormetic (provide benefit) in the way that reactive oxygen species bursts and other low level transient insults are. https://scholar.google.com/scholar?q=radiation+hormesis&hl=en&as_sdt=0%2C10&as_ylo=2010&as_yhi= From my reading of the literature doses for any CT procedure can vary alot from one facility to another, sometimes by a factor of 10. You should be able to a calcium scan with a total dose that is less than what you would get from natural background radiation (for a year) but you might have to pull teeth to get accurate exposure information from your facility. And don't use a hospital – it will cost 5 to 10 as much as a stand-alone imaging center. It's risk vs reward – if you're a typical middle-aged north american you probably have undiagnosed vascular disease of some sort and it is likely far more life-threatening and shortening than a little radiation.

  12. I strongly agree with the futility of stress testing. I have recently had a second heart attack which revealed plaque blockages not detected by a recent stress test (2 months) nor by an ecg conducted by a cardiologue.

  13. I am a dentist in the Cincinnati area, and have noticed on patients that we take panoramic radiographs on, that, in our patient population about 10 to 15 percent have what appear to be calcifications in their carotid arteries. I always ask that the patient let their physician know that we have found this, and offer to forward the radiograph to their physician. In the 8 years I have had digital radiographs and started being able to see this, I have had very few physicians interested in these findings, and have had only one ever ask for a copy of the radiograph. In some patients it is just a few spots, in others you can actually see the shape of the carotid because there is so much calcification. Is this an insignificant finding, or does this merit follow up?
    Terry Lowitz, D.D.S.

    PS Really like you channel!

  14. I had read that a CT scan of this magnitude had the equivalent of being exposed to radiation in nature for seven years. Sources may or may not have been reliable, but like you say, Dr. Brewer, that is low compared to the risks of heart attacks and etc. Hopefully most people don't have very much radiation in "nature" around them. I agree with you on that when I have lost so many, particularly men, in my family too too early from heart disease.

  15. Wow, your channel is not visible on my list even though it shows me as subbed for whatever reason. Taken off notifications as well. Had to look you up.

  16. Will be getting a CIMT test next week. My Podiatrist found a degree of atherosclerosis in my peripheral artery above my ankle. I am needing foot surgery (Morton's neuroma) and he said I needed to make sure this was ok by getting a CIMT, and a Cardiologist to examine things before surgery.

  17. In the Los Angeles area, do you know of a reliable CIMT screening provider? I do not think that Kaiser offers it. (Where I have my medical coverage) Thanks for any information you can provide.

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