CT coronary angiography is NOT a screening procedure

28. November 2008 William Davis (3)
I've recently had several hospital employees tell me that their hospitals offered CT coronary angiograms without charge to their employees.

Among these hospital employees were several women in their 30s and 40s.

Why would young, asymptomatic, pre-menopausal women be subjected to the equivalent of 100 chest x-rays or 25 mammograms? Is there an imminent, life-threatening, symptomatic problem here?

All of these women were without symptoms, some were serious exercisers.

There is NO rational justification for performing CT coronary angiography, free or not.

What they really want is some low-risk, yet confident means of identifying risk for heart disease. Cholesterol, of course, is a miserable failure in this arena. Framingham risk scoring? Don't make me laugh.

Step in CT coronary angiography. But does CT coronary angiography provide the answers they are looking for?

Well, it provides some of the answers. It does serve to tell each woman whether she "needs" a heart procedure like heart catheterization, stent, or bypass surgery, since the intent of CT angiography is to identify "severe" blockages, sufficient to justify heart procedures.

Pitfalls: Because of the radiation exposure, CT angiography is not a procedure that can be repeated periodically to reassess the status of any abnormal findings. A CT angiogram every year? After just four years, the equivalent of 400 chest x-rays will have been performed, or 100 mammograms. Cancer becomes a very real risk at this point.

CT angiography is also not quantitative. Sure, it can provide a crude estimation of the percent blockage--the value your cardiologist seeks to "justify" a stent. But it does NOT provide a longitudinal (lengthwise) quantification of plaque volume, a measure of total plaque volume that can be tracked over time.

What's a woman to do? Simple: Get the test that, at least in 2008, provides the only means of gauging total lengthwise coronary plaque volume: a simple CT heart scan, a test performed with an equivalent of 4 - 10 chest x-rays, or 1 - 2.5 mammograms.

Perhaps, in future, software and engineering improvements will be made with CT coronary angiography that reduce radiation to tolerable levels and allows the lengthwise volume measurement of plaque. But that's not how it's done today.
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Comments (3) -

  • Diana Hsieh

    11/29/2008 9:55:00 PM |

    I'm confused by your post.  From what I understand, the CT angiogram provides a superset of the data provided calcium scoring CT.  So when I got a CT angiogram this summer, I got a calcium score with it.  (Is that not standard?)

    Also, I worry that you're overstaing the radiation dose of the CT angiogram.  In a prior blog post, you wrote:

    "CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 chest x-rays or 20 mammograms. Now that's a problem.

    "The exposure is about the same for a pelvic or abdominal CT. The problem is that some centers are using CT coronary angiograms as screening procedures and even advocating their use annually. This is where the alarm needs to be sounded. These tests, as wonderful as the information and image quality can be, are not screening tests. Just like a pelvic CT, they are diagnostic tests done for legimate medical questions. They are not screening tests to be applied broadly and used year after year."

    I agree with your analysis that the CT angiogram delivers too much radiation to be used as a yearly screening test, but your radiation comparison numbers are way different in the two posts by a factor of four.  While such numbers may not be precise, that seems like a bit much.

    Full disclosure: My husband is a radiologist.  (He's msk not a body guy, so heart scans aren't his thing.)  His group performs both kinds of tests.  I'm definitely not promoting CT angiograms over CT calcium scoring.

  • Diana Hsieh

    11/29/2008 10:38:00 PM |

    OH OH!  I misread your post.  You said that "after four years" -- hence the four-fold increase in radiation.  Duh.  

    My question about the calcium scoring as part of the angiogram remains, however.  (I could repost that as its own comment if you prefer, however.)

  • Amna

    8/3/2011 11:41:22 AM |

    This is done with the help of a device called the catheter which is a thin, narrow, tube-like structure. Now, the images are studied to understand corrective measures needed to re-instill proper functioning of the heart.   Angiography hospital in Thailand

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Track Your Plaque and non-commercialism

Track Your Plaque and non-commercialism

29. April 2007 William Davis (6)
If you're a Track Your Plaque Member or viewer, you may know that we have resisted outside commercial involvement. We do not run advertising on the site, we do not allow drug companies to post ads, we do not covertly sponsor supplements. We do this to main the unbiased content of the site.

We've seen too many sites be tempted by the money offered by a drug company only to see content gradually drift towards providing nothing more than cleverly concealed drug advertising. I personally find this deceptive and disgusting. Ads are ads and everyone knows it. But when you subvert content, secretly driven by a commercial agenda, that I find abhorrent.

That said, however, I do wonder if we need the participation of some outside commercial interests to help our members. In other words, many (over half) of the questions and conversations we have with people is about what supplement to take, or what medication to take. While we cannot offer direct medical advice online (nor should we) because of legal and ethical restrictions, I wonder if could facilitate access to products.

Many people struggle, for instance, with trusted sources for l-arginine, vitamin D, fish oil. Other people struggle with finding a heart scan center because of the changing landscape of the CT scanning industry. Could we somehow provide a clear-cut segment of the website that clearly demarcates what is commercial and non-Track Your Plaque-originated, yet at least provides a starting place for more info?

Ideally, we would have personally tried and investigated everything there is out there applicable to the program. But that's simply impossible at this stage.

I feel strongly that we will never run conventional ads on the site. Nor will we ever permit any outside commercial interest to dictate what and how we say something. The internet world is full of places like that. Look at WebMD. I find the site embarassing in the degree of commercial bias there. We will NEVER sell out like that, regardless of the temptation. People with heart disease are all conducting a war with the commercial forces working to profit from them--hospitals, cardiologists, drug companies, medical device companies (yes, even they advertise to the public, e.g., implantable defibrillators--no kidding). Genuine, honest, unbiased information is sorely needed and not from some kook who either knows nothing about real people with real disease, or has a hidden agenda like selling you chelation.

I'd welcome any feedback either through this Blog or through the contact@cureality.com.
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Comments (6) -

  • Warren

    4/29/2007 6:02:00 PM |

    I agree with the need for some sort of unbiased but brand/manufacturer-oriented guidance.  I guess my question would be, if this content is not based on your specific experience, what criteria would you apply to determine how to assure some level of credibility?  With advertising, the criteria is generally willingness to pay the price of the advertising.  If you want to maintain higher standards than that, won't it require someone with either understanding or technical expertise or direct experience to assess whether the producer is credible and trustworthy?

    As it stands, I am looking for someone whose opinion I can trust regarding which supplement suppliers to turn to.  I have been impressed and surprised by the degree of your willingness to tell it the way you see it, including naming names of product manufacturers that you have found to supply products that seem to work for your patient population.  I hope you'll keep that up no matter what.  And I'm interested in how this idea develops.

  • Dr. Davis

    4/29/2007 8:31:00 PM |

    Thanks for the helpful thoughts.

    I wonder if a user comment method would work. In other words, say a product manufacturer makes a claim and sells their product to you (Track Your Plaque would not sell it), there will be comments from people who have tried the product and their supplier before.

    Such a system would not be as certain as providing our own stamp of endorsement (which we could still do, of course), but it would encourage an open conversation. Hopefully, any undesirable products would be rapidly identified as such.

    My concern is that, with hundreds or thousands of products out there, we end up saying "We've never tried it" all too often.

  • Eugene

    5/1/2007 3:38:00 AM |

    Dr. Davis for as much time and effort that is put in the TYP program, why not i'am sure the snake oil salesman would not want his product under the gun like people on this progran would do, frank discussions on supplements is not a bad thing as a example i'am the person who asked you about PGX fiber, its called WellBeX and is marketed by Natural Factors, one more example would be i use a insulin mimetic R-alpha lipoic acid with biotin (also a very good antioxidant) i can buy the brand name Insulow or i can use a different brand (Glucophase),for less money that does the same thing, being a type 2 i test all of the time and sometimes go days eating the same thing at the same time i know that i can get between 10 and 12 points with either one.  i know their are a lot of supplements but we only talk about a few, and like i said before why not, my biggest concern on buying supplements are they selling what they say they are selling or is it different item that will not work, or is made up with a different material than is is advertized. why not get some add revenue, their are good products out their, Upsher-Smith Slo Niacin, Endurance's Endur-acin SR both are good nicotinic Acid products, Insulow makes a good product, one more example would be the Vitamin Shoppe sells a  good Vitamin D softgel under their store brand this is a good product, but they also sell under their store brand a no flush Niacin in their heart supplement area , this product is worthless for the TYP program, I would say start with the products, that we know, and expand a little at a time, also how about Direct access testing for blood work, i use Lab Corp to get my NMR lipoprofile i'am sure that their are others full speed ahead, I think increased revenue could have some good outcomes
    Eugene

  • Dr. Davis

    5/1/2007 11:54:00 AM |

    Great thoughts.

    I think, if and when we proceed with such a process, that we:

    1) Have some sort of checklist for approval of quality, price, availability, purity, etc. and provide our stamp of approval.

    2) Convey our comments in addition to info provided by the manufacturer or distributor.

    3) Permit all the Track Your Plaque participants to leave their own comments, much like Amazon does with books.

  • Anonymous

    5/4/2007 3:42:00 AM |

    A record holder in plaque reduction has now been acheived.  What brand of supplements was the member using? What brand of fish oil? This is when a recommendation would be welcomed!!

  • Dr. Davis

    5/4/2007 11:36:00 PM |

    Nothing magical: He used Sam's Club fish oil.

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