The following
interview was conducted with Gregg
W. Stone, MD, Director of Cardiovascular
Research and Education, New York-Presbyterian
Hospital / Columbia University Medical Center. Dr. Stone is one
of the world's leading interventional cardiologists and was principal
investigator for
the TAXUS IV drug-eluting stent clinical trial.
Dr. Stone is also Vice Chairman of the Cardiovascular Research
Foundation (www.crf.org)
which sponsors the annual TCT meeting, the largest interventional
cardiology symposium in the world. |
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Q: Drug eluting stents have been called “revolutionary”.
Would you characterize these new devices this way?
Dr. Stone:
Drug eluting stents are a true revolution in the way we are
taking care of
patients with coronary artery disease because they,
one, obviously reduce the risk of restenosis, both angiographic and clinical,
in the patient by approximately 75% compared to a bare metal stent. Therefore
it’s much more likely that patients will be symptom-free for an
extended period of time after stent implantation, not require repeat
procedures, will have a better quality of life and will ultimately avoid
the need for bypass surgery. Number two, it’s a true revolution
because it’s allowing us to treat more complex patients than we
would otherwise in cases previously where we were sure
restenosis would occur. So now we’re able to treat much more complex
types of patients and those patients are also able to avoid the need
for bypass surgery.
Q: What kind of patients do you mean by “more complex"?
Dr. Stone:
Well, they’re more complex in that they’re, one, higher
risk, such as patients with advanced diabetes, and they’re more
complex in that the amount of atherosclerosis, or the amount of plaque
in the coronary arteries that we’re treating, is more extensive.
So the patients have more lesions, more blockages. They’ve got
a greater number of arteries involved than the three main coronary arteries.
In the past we might have treated one or two lesions in one artery. Now
we may treat three or four. Or sometimes five or six lesions in two or
three arteries. And be much more confident that we’re going to
be able to get a durable result. In addition, we tend to be treating
more complex lesions, such as bifurcation lesions, left main stenoses,
types of lesions that before had a very high risk of restenosis that
made us less likely to want to treat them.
Q: How were these types of patients treated previously?
Dr. Stone: They would be treated either with stenting with bare metal
stents and with a much higher risk of restenosis or by referral in
most
cases to bypass surgery.
Q: So with these new devices, do you see the bypass surgery
option probably shrinking even more than it has?
Dr. Stone: Yes. It certainly is a very
important, and remains an important viable option for patients with extremely
extensive coronary artery disease,
or those who continue to restenose after drug-eluting stents, although
that’s becoming less and less common. However I think 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.
Q: Is there any reason not to use a drug-eluting stent, if you
are going to stent a patient?
Dr. Stone: We certainly have proven the safety
of drug-eluting stents, and their efficacy in certain types of lesions
that have been studied in
the randomized trials, and there’s two such stents that have proven
to be very efficacious and very safe in these, what I would call, moderately
complex lesions, and that’s the Cypher stent which elutes a drug
called sirolimus, made by Cordis, and there’s the Boston Scientific
Taxus stent, which elutes a drug called paclitaxel. There are many types
of lesions though that have not yet been adequately studied with these
stents, such as lesions with thrombus or blood clot, acute heart attack
or myocardial infarction, bifurcation or left main lesions, saphenous
vein graft, in-stent restenosis – so for those types of lesions,
it’s hard to recommend drug-eluting stents because we still don’t
know that they’re entirely safe or effective. Our anticipation
is that they will be proven such in those types of lesions, but those
studies are just under way and may take another couple years before we
have all the answers.
Q: Angioplasty is the recommended therapy for people presenting
with acute MI in emergency rooms. What would happen
to a patient like that?
Dr. Stone: Right now the recommended treatment
for most of those patients is to put a bare metal stent in. We just don’t have the data yet to
know that it’s safe to put a drug-eluting stent in.
Q: In your practice, what percentage of balloon angioplasty
cases wind up with stents, and what percentage of stents do you see
being drug-eluting
stents?
Dr. Stone: In our practice I would say approximately 99% of all
cases are getting stents, as opposed to just balloon angioplasty alone.
The outcomes clearly
are better with bare metal stents compared to balloon angioplasty for
most patients and lesions, [if we have] an appropriate size stent. We
are kind of atypical at Lenox Hill Hospital.
We’re
probably implanting drug-eluting stents in more than 95% of lesions in
which we’re putting stents. But we’re doing that under a
very carefully controlled research setting to collect the outcomes data
in those patients. I would say that most hospitals are probably more
approximately 65%, although it probably ranges anywhere from still 40%
to again we are probably the upper end with 95% or more.
Q: What are the top issues that patients who
may be getting an intervention should be concerned about and questions
that they may
want to ask their physician?
Dr. Stone: I think that for patients,
they need to be informed completely about the risks and benefits about
drug-eluting stents -- one, in general,
and two, for their particular situation. So if, for example, a patient
has the type of lesion that drug-eluting stents have been proven safe
and effective for, then one, regardless of the cost, they should insist
on getting a drug-eluting stent for those types of lesions. Now, on the
flip side of things, they also should want to know whether the kind of
blockages they have are the type that haven’t been proven yet safe
or effective for drug-eluting stents. And for those types of lesions,
depending on the risk-benefit ratio, and that’s a discussion that
would be very individualized, that the patient would have to have with
the doctor. In that case the patient may decide that he or she either
should or should not desire a drug-eluting stent. So it’s not a
black-and-white issue, and the patient also needs to be informed about
the risk and benefits still of surgery as an alternative, and of medical
therapy as an alternative. The patient should be informed of what is
known about the safety and efficacy of drug-eluting stents, for his or
her particular clinical and anatomic situation and what isn’t known
about drug-eluting stents for that situation.
Q: When there were negative headlines back in October 2003
about thrombosis with the Cypher stent, worried patients were
calling their doctors
and hospitals.
What do you think is the role
of patient education in these situations?
Dr. Stone: I think patient education
is tremendously important. An informed patient is a patient who
not only understands what is being done
to him or her, but is one who can and should participate in the decision-making
process. I mean not everything we do as physicians is cut and dried.
There are risks and benefits in many of the decisions we make and I think
most physicians relish the opportunity to have an informed patient participate
in that decision-making process.
Regarding stent thrombosis in particular,
I think that whole issue was raised because of the rate that events were
occurring were deemed initially to be excessive, but then when cooler
heads prevailed, and actually scientifically tried to collect the data
and numbers to see whether or not they were similar to what was occurring
before the introduction of drug-eluting stents, we did in fact find that
the rates were very similar to the bare metal stent thrombosis experience.
Stent thrombosis has been with us since the initial days of balloon angioplasty,
let alone the initial days of stenting, and in fact in the past it was
much higher than it is now, either with bare metal stents or drug-eluting
stents. And it seems that people kind of forgot that fact when they were
getting so upset. People do die from stent thrombosis. [Stent thrombosis]
occurs in about 1% of patients and approximately
10-20% of those may actually die. So coronary artery disease is a dangerous
condition that develops in most people over a 50 or 60 year period, and
even with
our advanced interventional cardiology techniques today, there are still
risks of all the procedures we do. And patients need to understand the
risks and the benefits. In general the risks are significantly less than
if the patient does nothing, and goes along, given the natural history
of coronary artery disease in terms of plaques progressing to develop
a total occlusion which results in either myocardial infarction or death.
And, of course, we know for a long time now that stenting compared to
medical therapy alone significantly improves quality of life in terms
of reducing angina, reducing hospitalization, improving exercise tolerance,
etc.
Q: There have been reports of allergies with stents. Is
this a major problem?
Dr. Stone: I think that it’s exceedingly difficult to sort out
an allergy to a drug-eluting stent given that these patients are on multiple
medications, all of which I think are much more likely to cause hypersensitivity
and allergic reactions than the small amounts of the drug on the stents.
Now that being said and done, it probably does rarely occur, but again
it’s very difficult to sort out, but it’s not a problem that
I would tell patients to worry about.
Q: There currently are two drug-eluting stents available
on the United States. How does a cardiologist go about choosing which
one
to use?
Patients
often come in, having read newspaper articles, asking for a specific
product.
Dr. Stone: We often have that experience and it’s a combination
of factors that will go into the decision. There are going to be two
excellent drug-eluting stents on the market, again the Cordis Cypher
stent and the Boston Scientific Taxus stent. There are some potential
differences in those products in terms of the way, for example, diabetics
behave. Preliminary data suggest that diabetics may have a more favorable
long term response with the Taxus stent, for example. There may also
be differences in terms of flexibility, and deliverability of these stents.
A drug-eluting stent can only work if you can actually get it to the
lesion site. And for most patients we can get both stents to either area,
but for very complex patients, the newer Taxus stent is a more flexible
and deliverable stent, and so that may be preferable. And so again I
think that both stents are excellent, both stents are markedly better
than any bare metal stent that’s on the market, for the types of
lesions that they’ve been studied for and approved for, and the
exact decision between one versus the other, is probably less critical
than the decision to use a drug-eluting stent. The physician and the
patient, you know, should discuss in detail for her particular case,
which of the two stents would be more appropriate.
Q: What are patients’ responsibilities after the procedure?
Dr.
Stone: I think patients have a very important responsibility. Number
one, they’ve got to be compliant with the medications that are
prescribed for them. And, it’s aspirin for life; a
drug called thienopyridine, most commonly Plavix, or the generic name
is clopidogrel, which is very important to take for at least 3 months
with the Cypher stent, for at least 6 months with the Taxus stent, although
we’re in general prescribing that medication for at least a year
in all our patients, based on other studies that suggest they have favorable
effects, not stent-related, in terms of reducing death and myocardial
infarction. It’s possible that future studies will show that this
medication should be used long-term, for the life of the patient, but
we don’t know that yet. So we think somewhere between 6 months
and a year is appropriate.
In addition patients will be put on other
medications and asked to undergo lifestyle changes to significantly reduce
their cardiac risk factors for future events. And that’s critically
important that patients are very compliant with all efforts to get their
cholesterol, especially their LDL level, as low as possible, to quit
smoking, to lose weight to obtain more of an ideal body weight, to exercise
appropriately, control diabetes and high blood pressure to the extent
possible, and all of these makes a difference in the long term progression
of coronary artery disease.
Q: In other words, coming into the cath lab is not just going
to "fix it".
Dr. Stone:
Coronary artery disease is a process that develops in the
teens in most people and it’s a life-long illness. I kind of
make the analogy that it’s similar to when rust develops on a vintage
automobile. You can treat one area of rust that develops, and then you’ve
got to worry about two things: one, will the rust recur in the
place where you treated it, and two, will rust develop in other places
on the
body.
And once you get a vintage automobile it tends to be prone to rust and
so you’ve got to take excellent care of it or else that problem’s
going to continue. And the human body, especially atherosclerosis and
coronary artery disease is no different. This is a life-long illness,
and both angioplasty and bypass surgery are only palliative. They only
address the problem in a focal area, potentially for a short period of
time.
Q:
Sometimes when patients get the diagnosis they just think I’m sick
and I’m
going to stay sick. And while some of the risk factors are not modifiable,
some
are.
Do you think these new advances can give patients
hope?
Dr. Stone: Absolutely. I think there are a whole
series of avenues in which there’ll be advances, and certainly
genetics is going to play a central role in identifying patients at risk.
We may be able to identify which type of patient is going to respond
best to certain types of therapy, and that will be from genetic profiling. There’s going to be two stents for probably
the next several years; there are several other drug-eluting stents that
are undergoing clinical investigation and there will be iterations and
improvements in the existing and future ones. We’ll have new better-performing
stents, we’ll have multiple drug combinations on these stents,
we’ll have stents that are safer, that resist thrombosis, so the
future is very bright.
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