I don't care about hard plaque!

I ran into a cardiology colleague this weekend. He was aware of my interest in CT heart scanning and plaque reversal.

Out of the blue, he declared "I don't care about hard plaque! I only care about soft plaque." He then proceeded to describe to me how everyone--EVERYONE--needs a CT coronary angiogram to identify "soft plaque".

Is there any truth to this view? Are we only identifying "hard plaques" by focusing on calcium and calcium scores on simple CT heart scans?

Several issues deserve clarification. First of all, CT heart scans don't identify hard plaque. They identify total plaque. Because calcium is a component of the majority of atherosclerotic plaque, comprising approximately 20% of its volume, a calcium "score" can be used to indirectly quantify total plaque, both "hard" and "soft".

Anyone cardiologist who performs a lot of the procedure, intracoronary ultrasound, knows that most human plaque is also not purely soft or hard, it is mixture of both. (I've been performing this procedure since 1995.) Quantifying only soft or only hard plaque is therefore only possible in theory, not in practice.

I believe my colleague does have a valid point in one regard, however. There is indeed a small percentage of people, probably around 5% of all people who have CT heart scans, who have scores of zero yet have a modest quantity of pure "soft" plaque. These people may be misled by having a zero score. How can these people benefit from better information?

Several ways. First, people like this tend to have very high LDL cholesterols, generally 180 mg/dl or greater. They may have a very worrisome family history, e.g., father with heart attack in his 30s or 40s. This small proportion of people with zero heart scan scores may benefit from receiving X-ray dye with their heart scan, i.e., a CT coronary angiogram. Keep in mind that we're assuming everyone is without symptoms, also. If symptoms are part of the picture, everything changes.

But should everybody get a CT coronary angiogram? I don't believe so. A CT coronary angiogram involves far more radiation exposure, greater expense (usually $1800 to $4000), and, with present day technology, does not yield quantitative (measurable) information that is useful for longitudinal use for repeated scans. You don't want to undergo yearly CT coronary angiograms, for instance.

Stay tuned for more on this issue. In the meantime, I continue to try and inform my colleagues about what is right, what is wrong, what is preferable for patient safety and yields truly empowering information, and try to impress on them that the practice of cardiology is not just about enriching their retirement accounts.

Comments (10) -

  • Dave K

    11/18/2007 3:48:00 PM |

    Hello Dr Davis,

    Interesting post about hard and soft plaque.  I recently had a discussion with my GP regarding my serious increase in scan score (Jan 2006 = 235, Nov 2007 = 419).  

    After the first scan we started aggressively going after my LDL, HDL and Trig.. 196,59,221

    And have them down to 103, 65, 92 - we still have a way to go to 60/60/60 -

    So the increase is a suprise, but my doctor said that the increase could in part be cause some of the soft plaque had been converted to hard plaque and the scan would show that conversion.

    Does hard plaque register more than soft?

    Thanks for what you  are doing.

  • Dr. Davis

    11/18/2007 4:12:00 PM |

    Hi, Dave--

    I'm glad your doctor is working with you on gaining better control over your plaque growth.

    However, there is no such thing as soft plaque converting to hard plaque to increase calcium scores.

    Think of it this way: Calcium is a surrogate measure of TOTAL plaque, both soft and hard. In the majority of settings, there is little advantage to characterizing soft vs. hard.

    To seize better control, don't neglect: 1) hidden lipoprotein patterns, 2) vitamin D. Also see  our report "10 steps to take if your heart scan score increases more than 10% per year" at http://trackyourplaque.com/library/fl_02-006tensteps-2.asp.

    Good luck!

  • Dave K

    11/19/2007 4:50:00 PM |

    Dr Davis,

    Thanks for the response.

      I wonder if you are seeing any trends that indicate a "flywheel" or momentum in the creation of plaque.  I notice you have some patients that take two years or more to stop the growth.  

    Starting point Jan 06 - score=236
    Quit smoking - Jan 06
    Vitamin D - taking 1200
    Lost 20 #'s (5'11)=195
    Exercise 40min 4x
    Fish Oil = 1600 DHA+EHA
    Crestor = 10mg
    baby aspirin
    Basic good diet - no processed foods
    Oatmeal and blueberries/raisins everyday.

    This month = score=419

    After last scan
    just added Zetia
    Just quit all wheat products
    Considering quiting redwine - I tend to have 3-4 glasses versus the recommended 2
    Doctor is still saying no to L-arginine (not enough studies)
    Considering Niaspan

    Any comments?

    Thanks again - Dave K

    P.S. One more question... maybe this should be a separate post.  Do we know the exact connection between smoking and plaque?  Does it lower LDL size, lower HDL - iritate the lining of the vessels? Is it just elevated blood pressure?  What did my thirty years of smoking do to my heart (versus lungs)?

  • Dr. Davis

    11/19/2007 11:48:00 PM |

    Hi, Dave--

    I'm afraid there's too much to cover in this Blog. You will need lipoprotein testing and almost certainly require more than a baby-dose of vitamin D to gain better control over plaque growth. This rate of growth, however, is very concerning.  

    I would invite you to look at the hundreds of pages of discussion on the www.trackyourplaque.com website devote to just this question.

  • Anonymous

    11/20/2007 3:13:00 AM |

    Thanks Again Dr Davis,

    I have poured over your website and I'm still reading.  I plan to make your list of turn around "stars".

    BTW - here is the comment from my GP - sounds exactly like the cardiologist you mentioned in the original post.

    "Remember that although your coronary calcium score has gone up, this does not mean that you are at greater risk than you were a year ago.  Remember that the most dangerous plaque is the not-yet calcified soft plaque, which will not show up on an EBT.  It is only the safe, calcified plaque that can be measured with the EBT.   For your score to go up like it did, while your lipids came down so much, what had to happen was that lots of dangerous unstable plaque was converted to stable, calcified plaque.    There are no accepted guidelines for interpreting changes in calcium scores over time, because the scores tend to go up as treatment converts dangerous plaque to safer plaque.    We do know that aggressively lowering LDL reduces both unstable and stable plaque, and we know that risk can be further lowered by adjuvant therapy such as I listed above. "

  • Dr. Davis

    11/20/2007 3:44:00 AM |

    Sigh . . .

    It's amazing what a simple reading of the literature by your doctor would reveal to him/her.

    In near future, I will be posting some blogs that summarize crucial studies in the heart scan literature in an effort to provide better weapons in your fight.

  • Dave K

    11/20/2007 5:53:00 AM |

    Dr Davis,

    Thanks again for all you are doing and I look forward to whatever you can post.  I plan to challenge some of my GPs positions.  Your data certainly is of enormous value.

    Dave K

  • Dave K

    11/20/2007 5:57:00 AM |

    P.S. I going to 2000 vit "D" tomorrow.

    Also - have you thought about a "track-your-plaque" certification.  Something to indicate that our Drs are at least up to speed on the latest in *preventative* proceedures...?  I would switch.....

  • Dr. Davis

    11/20/2007 11:49:00 AM |

    Hi, Dave--

    Yes, excellent thought.

    It is something we'd like to aim for, but over the long term, since right now there are too few to make a difference. One by one, they are declaring themselves and separating from the "pack."

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    11/3/2010 8:48:59 PM |

    Stay tuned for more on this issue. In the meantime, I continue to try and inform my colleagues about what is right, what is wrong, what is preferable for patient safety and yields truly empowering information, and try to impress on them that the practice of cardiology is not just about enriching their retirement accounts.