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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.
This interview was conducted by Burt Cohen
of Angioplasty.Org on February 10, 2004.
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