Donít overrate electron beam CT
Guest opinion by Dan Fairman
Dr. Dan Fairman is a physician in the
Wood River Valley.
I love to read medical articles in
non-medical sources, such as newspapers and magazines. At times, I learn
something that is being acutely released in the press, sometimes before it has
had a chance to get to physicians. Late breaking news from the New England
Journal of Medicine is an example: sometimes results from trials are released to
the general press before the article has been printed in the Journal.
Other times Iíll read of new drugs or
treatments or trends in medical care that donít exactly make it to the
mainstream medical press. Some of these do have some validity, and some need to
be taken with a grain (or a pound) of salt.
So imagine my surprise at reading an
article by none other than Warren Miller on the benefits of electron beam
computed tomography, or EBCT, in the detection of heart disease! Warren Miller,
noted skier and filmmaker: I didnít know heíd also received a medical degree
along the way!
First, letís give some background. EBCT is
a fascinating application of technology. The ability to image the beating heart
is truly an advancement in radiology, and with this advancement, calcification
has been seen in arteries surrounding the heart. Calcification occurs when
atherosclerosis occurs over time, and reflects areas of plaque that have
hardened. Interestingly and importantly, this is not the kind of plaque that
will cause a heart attack. These areas that have calcified are not the type of
soft plaque that will rupture and cause heart damage or death. Soft plaque is
not visible on the EBCT.
So, what is the value of the EBCT, and
what is the value of coronary artery calcification? Simply put, no one is truly
sure. Daily physicians here and across the nation have patients request a "heart
scan", or will present to our offices with an EBCT that they had done "because
they should". Suppose you do have a heart scan, and it shows calcifications. The
physicianís first question is whether these are significant or not, that is,
whether there is limitation of blood flow to the heart. To find that out youíll
be scheduled for a different test, which is going to be a functional test, such
as a treadmill, sestamibi treadmill, or stress echocardiogram.
Suppose you donít have heart artery
calcification. Unfortunately, this doesnít mean you donít have heart disease: it
only means that any plaque you do have hasnít calcified yet. You still could be
at risk for a heart attack.
The American College of Cardiology, which
is the national organization of cardiologists, is also still unsure of the value
of the EBCT test. As one cardiologist put it, ĎItís a technology in search of an
As is true with a number of new devices
and technologies, there are people who will claim that this test saved their
life. There are cases that are really true; I have several patients who had the
test done, were found to have calcifications, and subsequent tests indicated a
need for stent placement or even bypass surgery, and you could claim the test
saved their life. Alternately, they could have gone to their doctor, had their
cholesterol and blood pressure measured, had a treadmill, and gotten the same
result. I also have other people who have had abnormal EBCT tests with normal
follow-up testing; for those people I recommend the same things as if they
didnít have an abnormal EBCT: change in diets, increased exercise, and control
of risk factors like cholesterol, smoking, and blood pressure.
So, is Warren Miller right? Maybe. Heís
sure a good skier, and I love his films. Your insurance company wonít pay for
the EBCT because itís still not a proven technology (besides the fact they donít
want to pay for anything, anyway). For now, most physicians think that EBCT is
interesting, and fascinating, but itís not the perfect answer to the question.