The Ultimate Guide To The Coronary Artery Calcium Scan (Score) Circa 2019

The skeptical cardiologist’s first post on coronary artery calcium (CAC) scan was posted in 2014 and had the wordy title “Searching for Subclinical Atherosclerosis: Coronary Calcium Score-How Old Is My Heart?”

This post still serves as a good introduction to the test (rationale, procedure, risks) but in the 5 years since it was published there has been a substantial body of data published on CAC and in 2018 it was embraced by major organizations.

Overall, I’ve written 20 posts in which CAC plays a predominant role since then and I feels it’s time to put the most important changes and concepts  in one spot.


Detection Of Subclinical Atherosclerosis: What’s Your Risk of Dropping Dead?

First, the rationale for using CAC (also known as a coronary calcium score or heart scan) is detection of “subclinical atherosclerosis”, a non-catchy but hugely important process which I describe in an early post on who should take aspirin to prevent heart attack or stroke:

We have the tools available to look for atherosclerotic plaques before they rupture and cause heart attacks or stroke. Ultrasound screening of the carotid artery, as I discussed here, is one such tool: vascular screening is an accurate, harmless and painless way to assess for subclinical atherosclerosis.

In my practice, the answer to the question of who should or should not take aspirin is based on whether my patient has or does not have significant atherosclerosis. If they have had a clinical event due to atherosclerotic cardiovascular disease (stroke, heart attack, coronary stent, coronary bypass surgery, documented blocked arteries to the legs) I recommend they take one 81 milligram (baby) uncoated aspirin daily. If they have not had a clinical event but I have documented by either

  • vascular screening (significant carotid plaque)
  • coronary calcium score (high score (cut-off is debatable, more on this in a subsequent post)
  • Incidentally discovered plaque in the aorta or peripheral arteries (found by CT or ultrasound done for other reasons)

then I recommend a daily baby aspirin (assuming no high risk of bleeding).


Help In Deciding Who Needs Aggressive Treatment

Second, CAC is an outstanding tool for further refining risk of heart attack and stroke and helping better determine who needs to take statins or undergo aggressive lifestyle reduction, something I described in detail in my post “Should All Men Over Sixty Take a Statin Drug”.

The updated AHA/ACC Cardiovascular Prevention Guidelines came out in 2013.

After working with them for 9 months and using the iPhone app to calculate my patients’ 10 year risk of atherosclerotic cardiovascular disease (ASCVD, primarily heart attacks and strokes) it has become clear to me that the new guidelines will recommend statin therapy to almost all males over the age of 60 and females over the age of 70.

As critics have pointed out, this immediately adds about 10 million individuals to the 40 million or so who are currently taking statins.

By identifying subclinical atherosclerosis, CAC scoring identifies those who do or don’t need statins.


This is particularly important for patients who have many reservations about statins or who are “on the fence” about taking them when standard risk factor calculations suggest they would benefit.


The Widowmaker

In 2015 I wrote about a documentary entitled “The Widowmaker” (see here and here) which is about the treatment and prevention  of coronary artery disease and what we can do about the large number of people who drop dead from heart attacks, some 4 million in the last 30 years:

The documentary, as all medical documentaries tend to do, simplifies, dumbs down and hyperbolizes a very important medical condition. Despite that it makes some really important points and I’m going to recommend it to all my patients.

At the very least it gets people thinking about their risk of dying from heart disease which remains the #1 killer of men and women in the United States.

Perhaps it will have more patients question the value of stents outside the setting of an acute heart attack. This is a good thing.

Perhaps it will stimulate individuals to be more proactive about their risk of heart attack. This is a good thing.

Although CAC has some similarities to mammography (both utilize low dose radiation, 0.5 mSV) I concluded that CAC was not “the mammography of the heart” as the documentary proclaims.

What We Can Learn From Donald Trump’s CAC?

In 2018 I noted that “Donald Trump Has Moderate Coronary Plaque: This Is Normal For His Age And We Already Knew It.”

In October, 2016 the skeptical cardiologist predicted that Donald Trump’s coronary calcium score, if remeasured, would be >100 .  At that time I pointed out that this score is consistent with moderate coronary plaque build up and implies a moderate risk of heart attack and stroke.

Trumps’ score gave him a seven-fold increase risk of a cardiovascular event in comparison to Hilary Clinton (who had a zero coronary calcium score) .

Yesterday it was revealed by the White House doctor , Ronny Jackson, that Trump’s repeat score  was 133.

I was able to predict this score because we knew that Trump’s coronary calcium was 98 in 2013 and that on average calcium scores increase by about 10% per year.

What is most notable about the Trump CAC incident is that Trump, like all recent presidents and all astronauts underwent the screening. If the test is routine for presidents why is it not routine for Mr and Mrs Joe Q Public?

At a mininum we should consider what is recommended for aircrew to the general public:

A three-phased approach to coronary artery disease (CAD) risk assessment is recommended, beginning with initial risk-stratification using a population-appropriate risk calculator and resting ECG. For aircrew identified as being at increased risk, enhanced screening is recommended by means of Coronary Artery Calcium Score alone or combined with a CT coronary angiography investigation.

The 2018 guidelines Take A Giant Step Forward

In late 2018 I noted that CAC had been embraced by major guidelines:

I was very pleased to read that the newly updated AHA/ACC lipid guidelines (full PDF available here) emphasize the use of CAC for decision-making in intermediate risk patients.

 

 

 

For those patients aged 40-75 without known ASCVD whose 10 year risk of stroke and heart attack is between 7.5% and 20% (intermediate, see here on using risk estimator) the guidelines recommend “consider measuring CAC”.

If the score is zero, for most consider no statin. If score >100 and/or >75th percentile, statin therapy should be started.

A Few Final Points On CAC

First, it’s never too early to start thinking about your risk of cardiovascular disease. I have been using CAC more frequently in the last few years in  individuals <40 years with a strong family of early sudden death or heart attack and often we find very abnormal values (see here for my discussion on CAC in the youngish.)

coronary calcium scan with post-processing on a 45 year old white male with very strong history of premature heart attacks in mother and father. The pink indicates the bony structures of the spine (bottom) and the sternum (top). Extensive calcium in the LAD coronary artery is highlighted in yellow and in the circumflex coronary artery in ?teal. His score was 201, higher than 99% of white male his age.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

If heart disease runs in your family or you have any of the “risk-enhancing” factors listed above, consider a CAC, nontraditional lipid/biomarkers, or vascular screening to better determine were you stand and what you can do about it.

Included in my discussions with my patients with premature ASCVD is a strong recommendation to encourage their brothers, sisters and children to undergo a thoughtful assessment for ASCVD risk. With these new studies and the new ACC/AHA guideline recommendations if they are age 40-75 years there is ample support for making CAC a part of such assessment.

Hopefully very soon, CMS and the health insurance companies will begin reimbursement for CAC. As it currently stands, however, the 125$ you will spend for the test at my hospital is money well spent.

The Importance of Proactivity

In “The MESA App-Estimating Your Risk of Cardiovascular Disease With And Without Coronary Calcium Score” I recently wrote that:

If you want to be proactive about the cardiovascular health of yourself or a loved one, download the MESA app and evaluate your risk.  Ask your doctor if a CACS will help refine that risk further.

There are many other questions to answer with regard to CAC-should they be repeated?, how do statins influence the score?, is there information in the scan beyond just the score that is important? Is a scan helpful after a normal stress test?

I’ve touched on some of these in the past, including the really tough  question “Should All Patients With A High Coronary Calcium Score Undergo Stress Testing?

Like most things in cardiology we have a lot to learn about CAC. There are many more studies to perform. Many questions yet to be answered.

A study showing improved outcomes using CAC guided therapy versus non CAC guided therapy would be nice. However, due to the long time and thousands of patients necessary it is unlikely we will have results within a decade.

I don’t want to wait a decade to start aggressively identifying who of my patients is at high risk for sudden death. You only get one chance to stop a death.

Apothanasically Yours,

-ACP


 

18 thoughts on “The Ultimate Guide To The Coronary Artery Calcium Scan (Score) Circa 2019”

  1. I am not sure how many times I have to keep posting this….

    I had a CAC test and my score was zero
    I had a PLAC test and my score was in the top 2% in other words very very high risk
    I had a stroke

    The above three were all in May/June 2018

    The CAC test is meaningless without a PLAC test and can give a totally false sense of security

    1. Chris,
      I don’t recommend the PLAC test. I agree with this Harvard Health assessment. “A repair enzyme that rides around the bloodstream attached to LDL (bad) cholesterol particles has been identified as a possible marker of atherosclerosis. This enzyme, called lipoprotein-associated phospholipase A2 (Lp-PLA2) appears to be involved in the release of substances from LDL that promote inflammation. Some (but not all) studies show a connection between high levels of the enzyme and heart disease.

      An FDA-approved test for the enzyme, called the PLAC test, is commercially available. It costs $150–$175, or about three times more than a test for C-reactive protein. Whether it adds important information remains to be seen.”

  2. Under what circumstances would CT coronary angiography be indicated in addition to, or in lieu of, a CAC? What are the pros and cons of the former compared to the later test?

    1. PMV,
      This is a great question, worthy of a scholarly review article (or skepcard post).
      CCTA (CT coronary angio) requires a venous injection of contrast, more radiation and is more expensive than CAC so it has generally not been considered a screening tool for coronary disease.
      CCTA precisely outlines the coronary anatomy, soft plaques, calcified plaques, lumen diameter as good or better than invasive coronary angiography whereas CAC just shows us very crudely where calcium is in the coronaries.
      The reference that Jeff Patten provided in his comment on this post (https://academic.oup.com/eurheartj/article/40/24/1906/5521840) has a fantastic figure which nicely demonstrates the differenc graphically.

    1. Jeff,
      Three fascinating articles!
      I was aware of the first which I think yields some insight into the process of calcification in arteries. Of course, the calcium is not the primary problem but more a marker of a repair process.
      The second I find absolutely fascinating. The lab that provided that false 2013 score should be investigated!
      The third I’ve touched on with at least one reader. My take right now- long duration exercise may lead to more calcium deposition in the coronary arteries but the overall benefits confer a benefit to CV risk. More studies needed.

      1. Fascinating. I wonder if aortic calcium could be an artifact of someone’s decade of marathon training?

  3. How does CAC compare to stress testing? If a stress test is negative (after say 12 min) but CAC is high, what should we think?

  4. I had my calcium test done after going to er several times with chest pain and having a stress testing done(witch I told them I would pass). My score came back saying that 90% of me my age were in better shape than me. I went several more times to er no one took me serious. I was 40ish 5′ 5″ 135lb. People looked at me as healthy. This last December I went back to er with bad pain. They put me in the waiting room. When the blood work came back I had a heart attach. The Dr that night was going to do a stress test again and I just started crying. Well he listened to me and did a heart catheterization. It was not long before they were telling me I needed cabg x 5. I’m still having problems and don’t think anyone is listening. They tried sending me home after surgery and I told them something was wrong. No one would listen. They did x-ray couple of times with nothing. The last one they did a nurse looked and said I have been doing this a long time and something is there. She got things done. They took a litter of fluid out of my chest. I think it’s same thing now and who ever is reading it just can’t see it. I don’t want something else to go wrong. I did not show normal signs with any of this. I have a high tolerance for pain. Just wanted to share with you. Having the heart scan done is something every one should do and it should be taken seriously. I really appreciate what you have wrote and what you are doing. You are making a big difference. If I can help in any way. Thank you!

  5. So does a cac scan of 0 coupled with aortic calcium denote an increased risk of heart attack needing an intervention of some sort or is the CAC of 0 reassuring at all?

        1. It’s not clear if this question is referring to aortic valve calcification versus calcification of the aorta. A little calcification on the aortic valve is common in the echocardiograms of older individuals, especially if they have hypertension. All of the factors that influence that aren’t clear but high Lp(a) should be considered.
          I recently had a patient who had a marked area of calcification in the proximal aortic root. Further evaluation revealed a markedly elevated CAC.
          I would consider significant calcification in the aorta as a marker of atherosclerosis.

          1. Thank you Dr. The actual comment on CAC scan was “a few punctate calcifications noted in ascending aorta just above level of the sinuses of Valsalva. Otherwise no significant vascular abnormalities”.

  6. this is a fascinating thread – obviously to those of us with Heart Disease. My question: as an asymptomatic 60YO with a CAC > 90th percentile there is not much information or guidance online. After a year of research + a good cardiologist I have the exact same prescription as someome with a total score of 100+. Seems like something is missing.

  7. Interesting. Here’s an observation regarding statins for the skeptic. I am not on statins. After my doctor suggested I go on a low dose of simvastatin about 7 years ago I got horrible inflammatory side effects. My upper body was frozen. I stopped taking them. I also took an angiogram that showed zero plaque which followed two CACs taken 5 and 10 years prior that showed zero plaque. By the way the angiogram at Cedars Sinai in LA cost $500. I paid for it out of pocket and thought it quite cheap relative to the cost of taking statins for the rest of my life. At that point, I did more research on statins and realized that far too much of the research going back to the Framingham study was sophomoric, scientifically dubious at best and was incapable of ascertaining long term ancillary impacts to the body. I became a huge skeptic. When the FDA finally said in 2015 that dietary cholesterol had no material impact on serum cholesterol there was some vindication and an admission of a point that cholesterol skeptics had been saying for years. I also note that the FDA announcement got little coverage.

    One of the things I came across in my research was the chart below in the US National Institute of Health Chart Book for 2012. Here’s what jumped out at me from Chart 3-9. This is a linear chart, not logarithmic, so the data are pretty simple to visualize. (not able to post)

    While the data begin in 1979 it indicates a linear decline in age-adjusted CVD deaths from1979 through 1987) when statins first came on the market (I believe it was Lovastatin on 9/1/87). Readings suggest that this decline (I do not have prior data) is attributable to prior anti-smoking campaigns begun as far back as the 1960s and ongoing improved medical procedures. Once statins hit the market in late 1987 and their use grew to what I would call epidemic proportions, the rate of decrease did not change. There was no significant “bending of the curve” and there is no indication of millions or even tens of thousands of lives saved. THe decrease isvirtually a straight line. If statins were the panacea that they have been cracked up to be, the curve should have plunged to the lower right between 1988 and 2008. It doesn’t. I have looked for updated numbers and can’t find any. In fact, I can’t find this chart in more recent National Institute of Health publications.

    While there can be many interpretations of this chart i.e. someone taking statins in 1987 doesn’t die of CVD until 2000 or they live long enough to die of something else or be classified as something else at death, there is no clear demarcation that suggests that statins have anything to do with CVD deaths.

    I have one other observation. When I started taking simvastatin I got a bad case of trigger finger in my right index finger…very annoying but not life threatening. Almost as soon as I stopped taking Simvastatin the trigger finger went away completely and has not returned. The connection was obvious and immediate. That made me look into statins even more and convinced me that these mystery drugs had side effects that were totally unknown probably at least some related to inflammation. The other thing that came to mind was dementia which may or amy not be inflammation related– most bad things are. I am just recently starting to see suggestion that there may be a connection. I had learned that 25 percent (I have seen higher numbers) of the body’s cholesterol was in the structure of brain cells, and as the FDA admits serum cholesterol, is not materially influenced by dietary cholesterol (i.e., natural cholesterol). My ake is that cholesterol levels are probably not something you want to mess without a damn good reason. While there is nothing scientific about that is, IF I saw, data suggesting that cases of dementia started increasing in the western world beginning in the late 1980s I would not be shocked. That may be somewhat Ancel Keyesian but let’s just say it wouldn’t come as a surprise.

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