The Nation's Health + [Heart scans]

Heart scans: 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.