Heart scan tomfoolery

Heart Scan Blog reader, Steve, sent these interesting questions about his heart scan experience. (I sometimes forget that this blog is called "The Heart Scan Blog" and was originally--several years ago--meant to discuss heart scans. It has evolved to become a much broader conversation.)

The answers are a bit lengthy, so I'll tackle Steve's questions in two parts, the second in another blog post.

Dr. Davis,

I had a heart scan last year. The score was 96. While not a horrible score, it
was a wake up call, and I changed my lifestyle.

I had another scan this year and the heart scan score went up to 105, but the
volume score went down from 141 to 136.

The report I received said this:

'The calcium volume score is less in the current study as compared with the
original or reference study. This is an excellent coronary result and indicates
that there has been a net decrease in coronary plaque burden. The current
prevention program is very effective and should be continued.'

This is all well and good, but I have two questions:

1. Am I really going in the right direction even though the heart scan score
went up 9%?

2. Here are results that make no sense to me:
- Left Main volume went up from 22.4 to 35.6
- LAD went down from 95.2 to 91.3
- LCX volume went down from 23.2 to 0
- RCA volume went up from 0 to 9.3

Why would there be so much variation from year to year, and why would the plaque
move from site to site?


Questions like Steve's come up with some frequency, so I thought it would be worthwhile to discuss in a blog post.

First of all, the conventional heart scan score, or "calcium score" or "Agatston score" (after Dr. Arthur Agatston, developer of the simple algorithm for calcium scoring, as well as South Beach Diet fame), is the product of the area of the plaque in a single CT "slice" image
multiplied by a density coefficient, i.e., a number ranging from 1 to 4 that grades the x-ray density of the plaque. (1 is least dense; 4 is most dense.) A density coefficient of 1 therefore signifies some calcium within plaque, with higher density coefficients signifying increasing calcium content and density. Incidentally, "soft" plaque, i.e., non-calcified, would fall in the less than 1 range, even the negative range (fatty tissue within plaque).

The volume, or "volumetric," score is the brainchild of Drs. Paulo Raggi and Traci Callister, who expressed concern that, if we cause plaque to shrink in volume, the density coefficient used to calculate the calcium score would increase (since they believed that calcium could not be reduced, contrary to our Track Your Plaque experience, thereby leading to misleading results. They therefore developed an algorithm that did not rely on density coefficients, but used the same two-dimensional area obtained in the standard heart scan score, but replaced the density coefficient with a (mathematically interpolated) vertical axis (z-axis) measure of plaque "height." This 3-dimensional volumetric value therefore provided a method to generate a measure of calcium volume. In their original publication, the volume score proved more reproducible than the standard calcium score. This way, any reduction in plaque volume would not be influenced by the misleading effects of calcium density, but reflect a real reduction in volume.

Callister and Raggi's study also highlighted that calcium scoring in any form is subject to variability. Back in 1998 (when their study was published), there was a bit more variation than today due to the image acquisition methods used. But, even today, there is about 9% variation in scoring even if performed repeatedly (with less percentage variation the higher the score).

Unfortunately, volume scoring never caught on and the calcium score has been the most commonly used value by most heart scan centers and in most clinical studies. And, in all practicality, the two values nearly always track together: When calcium score increases, volume score increases in tandem; when calcium score decreases, volume score decreases in tandem.

Steve is therefore an exception to the general observation that calcium score and volume score travel together. Steve's calcium score increased, while his volume score decreased. From the above discussion, you can surmise a few things about Steve's experience:"

1) In all likelihood, the changes in both calcium score and volume score could simply be due to variability, i.e., variation in the placement of his body on the scan table, variation in position of the heart, variation in data acquisition, etc. There is a high likelihood that neither value changed; both are essentially unchanged.

2) If the changes are not due to scan variability, but are real, then it could be that the calcified plaque is reduced in volume but increased in density. If true, this is probably still a favorable phenomenon, since plaque volume is a powerful predictor of coronary "events" and an increase in plaque density is likely a benign phenomenon. It would also raise questions about the adequacy of vitamin D and vitamin K2 status, both major control factors over calcium deposition and metabolism.

So, in all likelihood, Steve's apparent discrepant results are modest good news, especially since calcium scores can ordinarily be expected to increase at the rate of 30% per year if no action is taken. Experiencing no change in score, calcium or volumetric, carries a very excellent prognosis, with risk for heart attack approaching zero. (I'm impressed that Steve accomplished this on his own, something the majority of my colleagues haven't the least bit of interest doing.)

Part 2 of Steve's question will be tackled in a separate post.

Comments (12) -

  • Ed Terry

    11/4/2010 4:27:46 PM |

    After two years my volumetric score decreased 14% annually, but my Agatston score increased by 33%.  For the Agatston score, a pulsation artifact was noted.  My cardiologist could not explain to me what that was.  Unfortunately, each scan was performed using a multi-slice detector CT instead of an EBCT.

    Could the increased Agatston score be due to the pulsation artifact?

  • Anonymous

    11/4/2010 10:32:18 PM |

    Can a person have a high calcium score yet "ideal" lipids -- low tris, high hdl and low ldl, very low crp?

  • David

    11/6/2010 8:35:57 PM |


    Yes. Lipids show you a snapshot of a single point in time, and are not a guarantee of anything. Think of it this way: Say you've been eating garbage all your life. Cookies, candy, pizza every night, etc. On top of this, you started smoking when you were 15. Now fast forward. You're 50 years old, you've been putting garbage in your body for almost your whole life, and it hits you: I need to cut this out. So you clean up your diet and give up the candy, cookies, pizza, and cigarettes. You get serious about getting in shape, and start exercising regularly. A couple years go by and you stay consistent with your new lifestyle. You get your lipids checked, and wow! HDL is nice and high, LDL is low, trigs are low, etc. This is great, but it doesn't tell you anything about the damage that's already been done over the last 50 years of bad habits. You could have developed a lot of plaque over your lifetime regardless of what your lipids say now. Lipids are sensitive to changes in diet, and change rapidly regardless of plaque burden.

  • pierogi

    11/6/2010 11:54:02 PM |

    Good questin..Good answer.
    However do good lipids stop,slow or reverse calcium score?

  • David

    11/7/2010 5:05:18 AM |


    Regardless of the exact mechanism that is truly behind the arrestment of plaque growth, there are definitely certain lipoprotein patterns that are associated with low-risk and plaque regression, so those are the types of patterns we shoot for. The direction of the causal relationship and all the players involved is not completely clear in my mind, though certain lipoproteins, such as HDL2, seem to play an active causal role in such tasks as reverse cholesterol transport, reduction in inflammation, etc.

  • Sara

    11/7/2010 6:09:42 AM |

    the 4-60's is a great target for reversing cad:
    hdl, ldl, trigs, vit.d

  • Dr. William Davis

    11/8/2010 1:40:30 AM |

    Wow, David.

    Excellent description of how this works. Thanks for listening!

  • Samual

    11/9/2010 4:20:20 AM |

    Its fantastic Blog.The Infrastructure and technology are the reasons for India being touted as one of the favourite destinations as India medical tourism.

  • buy generic viagra

    11/9/2010 5:45:43 AM |

    Calcium are very essential for human bones..It improves the growth of bones.

  • pammi

    11/9/2010 10:34:21 AM |

    Heart  disease is one of the most  dangerous disease which takes thousands of life every years all over the world. If we know its symptoms and Treatment for heart disease. We can prevent is to large extent.

  • Anonymous

    11/9/2010 5:52:54 PM |

    David -- thank you for your response.  Very helpful.  My problem is a doctor who is clueless about real risk factors.  She dismisses my concerns about heart health because she says I have "spectacularly high" hdl. At least she does not push statins on me.  Total cholesterol is high by  conventional standards and bounces around from 220 to 295, but the ratio between HDL and LDL and Triglycerides ("Tris") are always consistent and have been so for over a decade -- I keep my medical records.  Tris are generally under 50.  HDL is virtually always over 100.  C-reactive protein is always very low.  I do take small amount of thyroid meds -- 60 mg Armour plus 2.5mcg of cytomel.  I tried to explain that at my age -- I need to know what kind of hdl.  I also told her I am concerned about having ferritin at high end of normal (with no periods -- that may soon be even higher) and she laughed it off saying most women are worried about anemia. She had no idea about the different kinds of hdl.  I just turned 47 -- menstrual cylcles seemed to be stopping.  I am 5'2.5" and weigh 103.  I have not eaten wheat for around a decade and have been a low carber for much longer. I don't eat grains of any kind and vascillate between a paleo style low carb and one that includes some dairy. My family history is full of type 2 diabetes -- both parents and brother.  I have a meter and check my glucose fasting and post prandial etc.  Doc says I'm crazy.  I'm a stress eater and during binges -- I overeat nuts and nut butters or very dark chocolate -- 85% cocoa content.  I am never tempted by or crave baked goods or grains at all.  I was eating very small amounts of low carb fruit but find that it destabilizes my blood sugar and isn't worth it. Fasting is mid-80s but AIC has been edging up and doc does not understand that is why I am now testing after meals etc. Lately I've had extreme exhaustion and doc laughs it off as menopause symptom but I am concerned about my heart health.  I eat copious amounts of fat -- just love it -- not a carb craver.  Wondering if that could be insulin resistance? Any advice?

  • David

    11/10/2010 4:39:20 AM |


    If you're not happy with your doctor, I would suggest looking for a new one. Also, if you want an advanced lipoprotein analysis and your doctor won't do it, you can always do this yourself. Go to www.privatemdlabs.com and order an NMR LipoProfile. It's fairly inexpensive and super easy. You pay online, go get your blood drawn at a local lab, and then get the results emailed to you in a couple days.

    Wow, your HDL is really up there, and triglycerides are nice and low. Has it been this way all your life? Some people have a genetic deficiency of CETP (cholesteryl-ester transfer protein), which makes it so that the transfer of cholesterol between lipoprotein particles (like HDL to VLDL) is impaired. Of course, this means that HDL will go UP while trigs will stay pretty low. This also often leads to lower amounts of small LDL particles. Have you ever had your LDL size checked?

    I don't know what is causing your fatigue, but suggest that you keep pressing your doctor until you figure it out. Again, if your doctor just laughs off all your concerns, maybe it's time to look for a new doctor. Personally, I would reassess your hormone situation, including thyroid, and aim for optimal correction of all pertinent parameters.

    Have you had a heart scan? What better way to put your mind at ease and/or determine the true nature of your risk? There is a wealth of information here on Dr. Davis' blog as to why this could be a good idea to discuss with your doctor (hopefully she won't laugh it off!).