April 2005 Archives:
April 27, 2005
BEACH at the Jazz
Breaking news about new therapies from the 14th
Annual Peripheral Angioplasty and All That Jazz meeting in
New Orleans, namely the BEACH trial, or the Boston Scientific EPI: A Carotid
Stenting Trial for High-Risk Surgical Patients. (Does anyone
think we may need more letters in our alphabet to accomodate these
clinical trials?)
A revolution in the treatment of vascular disease
has been happening and in the past six months there have been several
big developments in the treatment of stroke. Angioplasty and stenting,
usually thought of as a treatment for heart disease, is now being
used throughout the body and last year, the FDA approved the first
device for use in the carotids. There had been much talk in earlier
days that carotid stenting was not as good as its surgical counterpart,
called cartoid endartarectomy (CEA). However, the SAPPHIRE
Trial, published in NEJM in October, not only showed the two
treatments similar in outcomes, but in the patients studied, who
were at high risk for surgery, there was almost 40% lower risk of
death, stroke or heart attack with stents (20.1% for surgery; 12.2%
with stent).
Today, the one-year
BEACH trial data were presented by Dr. Christopher White of
the Ochsner Clinic in New Orleans and these major complications
for high-risk patients are now at 9.1% -- this was with Boston
Scientific's WALLSTENT and FilterWire system, not yet approved
for use in the U.S. (the only carotid stent currently approved
is Guidant's AccuLink -- and that was just
approved last August).
I'll be discussing the implications of this new
technology, and its meaning for patients, in an upcoming report on
carotid stenting. Also in an interview, to be posted later today,
with Dr. White.
April 12, 2005
The SYNTAX of the "Big Q"
Today Boston Scientific launched the SYNTAX
clinical trial, to assess the current state-of-the-art comparison
between surgery and catheter-based intervention. Recent clinical
trials (discussed here) have focused on competing devices, Taxus
vs. Cypher, Endeavor vs. bare metal stents, and so forth. But SYNTAX
is going for the "big question".
Since its beginnings almost three decades
ago, the "big question" for interventional cardiology
(and interventional or "endovascular" therapy in general)
has been whether or not it is durable enough to replace standard "open" surgical
procedures. A wish of Andreas
Gruentzig (inventor of coronary angioplasty) was to see a randomized
trial comparing angioplasty (in his time that meant POBA, or Plain
Old Balloon Angioplasty) to CABG, or Coronary Artery Bypass Grafting.
Many cardiac surgeons scoffed at his technique and thought at most
it would apply to 5% of patients.
Such a trial never occurred in his lifetime, but
several have been concluded since (BARI, EAST, etc.) and the general
findings are that for many patients there is little difference
in the outcomes between PCI (Percutaneous Coronary Intervention)
and CABG, so the less-invasive angioplasty seems the winner (about
a third of PCI patients have needed a repeat procedure, but this
no longer may be the case). PCI is also indicated if you are not
a candidate for surgery, due to age or other health problems, or
if you factor in some of the central
nervous system function disturbance reported with bypass surgery,
or if you like lying on a table in a cool room, listening to whatever
CD the cath lab is playing that morning, while a cardiologist threads
devices into your coronary arteries -- then angioplasty is best --
especially because it takes about an hour or so, usually only an
overnight in hospital and a short recovery at home -- no zipper scar,
etc.
These same studies showed, however, that for the
most complex patients, diabetics or those with left main or significant
multivessel disease, bypass surgery was the way to go because the
PCI results were just not as "durable" -- there was too
high a rate of revascularization or complications.
Enter the drug-eluting stent, called a revolution
by some, and many of the less-than-perfect outcomes of PCI have been
waved away -- recent studies with both currently approved DES (Cypher and Taxus)
have shown great efficacy across the board in diabetic patients,
and the Taxus V study showed great advances over bare metal stents
in patients with multivessel, small vessel and wide vessel disease
(implications for successful treatment of the left main, a wide vessel).
Conditions that previously had been considered extremely high chance
for restenosis, and therefore not worth doing, are now in play.
So with today's SYNTAX trial, current angioplasty/stenting
(not the technology from 5 or 10 years ago) will be going head-to-head,
okay...heart-to-heart with bypass surgery. Some doctors have been
signaling a sea-change. Recently, Gregg W. Stone of Columbia University
Medical Center in New York told
Angioplasty.Org that:
"...for general referral, most patients
now, we think well over 90% with coronary artery disease can
be managed with angioplasty and implantation of a stent like
the Taxus stent."
Now a randomized clinical trial of over 4,000 patients
is going to test that hypothesis. If the outcomes for patients with
advanced and complex disease show PCI/angioplasty with drug-eluting
stents (a procedure involving a small puncture and an hour or so
of time with an awake patient) is comparable to open surgery (which
involves opening the chest, several hours of surgery under general
anesthesia and a considerable recovery time) then, as Dr. Marie-Claude
Morice (who announced the first SYNTAX patient) stated:
"The results of this study may profoundly
change the practice of medicine."
You may call this "hype". But check out
this quote, regarding surgery:
"This last part...namely operations...is
a tacit acknowledgement of the insufficiency of surgery. It is
like an armed savage who attempts to get that by force which
a civilized man would get by stratagem."
Says who? Says John
Hunter, considered the founder of Scientific Surgery, as
he wrote over two hundred years ago in The True Principles
of Surgery (1777). More on the stratagem to follow.
April 11, 2005
MRI & Stents
There have been questions for years whether it is safe to perform Magnetic
Resonance Imaging (MRI) on patients who have been stented (MRI safety was
one of the earliest
queries to Angioplasty.Org's discussion forum). The concern has been
whether the magnetic field produced would move a metal stent that had been
implanted in a vessel. The recommendations have been to wait a month or
two. However, last
week the FDA said that it was okay to conduct an MRI immediately post-procedure,
if the stent was Boston Scientific's Taxus Paclitaxel-Eluting Stent, that
is -- the first time a stent has been approved for immediate MRI -- important
for a couple reasons.
First, there has always been increased concern
about MRI and drug-eluting stents (DES) in particular, since the
concept of DES is to slow down or reduce the growth of the endothelial
layer over the metal stent and thus reduce the chance of restenosis
or reclogging of the vessel -- but not so much as to prevent a
thin layer of endothelial cells from covering the stent's surface,
which embeds the artificial structure in the arterial wall. The
question's been, does this increase the stent's "movability",
for a time anyway.
The second point is that, while some cardiologists
believe there isn't a problem and have been sending recently-stented
patients to MRI for a while now (see comments by Dr. Thomas Gerber
of the Mayo Clinic on members only theheart.org)
last week's ruling should relieve any physician/patient anxiety,
at least where the Taxus is concerned. Johnson & Johnson's
Cypher DES has not gotten an approval for immediate MRI yet (although
they are working on it) and they
recommend an eight week wait post-stenting with the Cypher.
And again, my mantra -- developments in this
field change so rapidly -- even the American Heart Association's
web site still recommends
against an MRI for at least four weeks after stent implantation,
without a cardiologist's approval -- which is still a lot better
than some major heart web sites that have just "discovered" that
drug-eluting stents "may reduce restenosis".
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