The Nation's Health

CT coronary angiography is NOT a screening procedure

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.