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June
29,
2008 -- 1:45pm EDT
Misleading Report on CT Heart Scans
For those in the cardiac imaging field who felt a sense of relief in March
when Medicare decided
against eliminating coverage for most CT angiograms, don't spoil your
summer weekend by glancing at this morning's New York Times.
The headline is a point-of-view give-away: those money-grubbing
docs, needlessly exposing their patients to dangerous radiation
just to
make a buck!
(Odd that
this article would appear in the midst of a giant
political battle on Capitol Hill over big Medicare cuts for physicians.)
It's a lengthy
article and includes quotes from many sources. The authors, Alex
Berenson and Reed Abelson clearly did a lot of legwork, but they
vaulted over significant
pieces of information that would definitely muddy up their thesis.
Evidence-Based Medicine
The article states that
CT Angiograms (CTA) have not been studied in a randomized clinical
trial to show that they positively affect patient outcomes; therefore
their benefits remain unproven. But this benchmark has never
been applied to any of the currently-used imaging technologies, ever
--
(see Dr.
Harvey
Hecht's editorial in a recent American Journal of Cardiology,
"The
Deadly Double Standard").
Radiation Risk
The authors discuss the radiation exposure from CTA a number of times,
yet fail to note that the radiation dose from the widely-used nuclear
stress test is the same, if not higher. Moreover, this past
year has seen numerous advances to significantly
cut the dose for CTA.
CTA Will Lead to More Testing
Actually, the opposite effect is cited by many imaging
specialists who point to the fact that more than a third of
the million invasive cardiac catheterizations currently performed
annually in the U.S. are negative: the arteries are clear, the patient
has no disease.
So how do these patients with no disease wind up
on the cath lab
table? Very often because of
false positives from nuclear stress tests, often in women. Multislice
CT Angiograms are 99% accurate in identifying patients
with no
coronary disease (see the CorE
64 study) so in many of these cases, both a nuclear stress test and
invasive catheterization could have been avoided by using a single
non-invasive less-risky test: the CT angiogram.
Use of CTA is Indiscriminate
A big section
of the article, cutely titled "Impatient Patients", is devoted to
the patient in the front page photo, Mr. Robert Franks, who had a
strong family
history of
fatal heart disease (a
father and two uncles). We are told he is basically healthy and
on statins which helped
get his LDL to 60, he had a clean nuclear stress test, but a somewhat-elevated
calcium score. The patient wanted a CT Angiogram, and Dr. Hecht of
Lenox Hill Hospital agreed. The "appropriateness" of this
decision becomes the subject of a "debate" between
Dr. Hecht and Dr. Ralph Brindis, head of cardiology for Kaiser in
Northern California. Brindis reportedly states that Hecht had erred
in
prescribing an unnecessary test, and is quoted as saying, "...the
concept of doing serial CT testing on asymptomatic patients, I think,
is
abhorrent. I cannot justify that. "
But here's what we are not told. The
patient was experiencing chest pain which, according to Dr. Hecht
(I contacted him), was one of the major reasons for the CT scan,
especially in light of the clear stress test. The New
York Times never mentions this critical symptom -- not to its readers,
and perhaps not to Dr. Brindis. One would have to wonder why?!
Did not the authors' colleague, Tim Russert, who also
had an elevated calcium score, pass his stress test with flying colors
just a month
before his fatal heart attack? His doctor told NBC that
the autopsy showed "significant coronary artery disease in the
Left Anterior Descending coronary artery." 15 minutes in a CT
scanner would have revealed this -- the scan wouldn't have prevented
the tragedy, but the elevated risk it indicated perhaps could
have been treated more aggressively.
Industry is Pushing CT Inappropriately
I'll only point out here that the authors cite "evidence" that
industry is behind
the CT push by painting a picture. They write, "As
more than 13,000 heart doctors gathered in Chicago in late March for
the annual American College of Cardiology conference, the biggest and
best-located booths belonged to General Electric, Philips Electronics,
Siemens
and
Toshiba, the leading makers of the machines used for CT angiograms."
I
might point out that these four companies also manufacture and
display every imaging device and modality used by all cardiologists,
from full-blown catheterization labs (which take up the majority
of their exhibit space) to X-ray
units, MRI systems, ultrasound devices and yes, even nuclear
stress units. They have very large booths, because all
this equipment is...well...very large!
Cowboys
Finally, a personal peeve is that the article implies that Dr. Hecht
and other CT enthusiasts are opportunists
or cowboys, hitching to a
new and untried technology, when the fact is that many
of these imaging specialists have been in practice for several
decades, and their opinions about CT are founded in their experiences
with other imaging technologies.
Of course any new technology can be overused, abused,
applied incorrectly, etc. That's not what we're talking about here.
We're talking about an important imaging technology that has been
studied, discussed, compared, complete with Appropriateness
Criteria guidelines issued jointly two years ago (!!) by all the professional
cardiology and radiology societies. The leaders in this field, including
the founding members of the Society
of Cardiovascular Computed Tomography (SCCT), are very concerned that
this technology is used appropriately and their concerns are reflected
in the series of interviews we publish in the "Imaging
and Diagnosis"
section on Angioplasty.Org
Dr. Hecht, in particular, was involved in
the pioneering stages of coronary angioplasty,
when he was assessing the results of balloon dilatation with
nuclear scans. As
he states at the
close
of his
interview on Angioplasty.Org, "I
have a huge background in both nuclear and stress echocardiography,
and CTA is simply a better test. It's time to move to the better
test."
And now, back to my weekend....
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