1. 018 门诊 CLINIC
东闻视野·国际瞭望 outlook
Bioresorbable Scaffolds are the Future!
Dr. William Wijns Cardiovascular Center Aalst, Belgium
With its development, several questions have been raised and more intensely discussed in regards to BRS,
such as the balance between degradation and scaffolding, the ideal material that will be used in the future,
inflammation during resorption, the best indications of BRS etc. And almost every academic conference on
cardiovascular field will address these questions. In the past 2015 CIT, the Director of EuroPCR, Dr. William
Wijns presented several speeches on the rising BRS technology, which covered the current development
and future possibility of BRS in depth. In answering the interview of Clinic, Dr. Wijns generously divulged
his perspectives over the hot focus on BRS and opened for us a wide scope to realize the future of this
technology, which will be seen over time.
“Future is the age of BRS… the question is when it will come up… personally, I say it will be
between 5-10 years.”
——Dr. William Wijns
Clinic: Has the current BRS achieved the balance
between its degradation and scaffolding? How does
patient accept to be implanted a resorbable scaffold
in real world?
Dr. William Wijns: We can discuss this from a theoretical
perspective based on polymer physics; but in fact, we have now
quite some experience with the BRS scaffold from Abbott.
Good data have been reported particularly through sequential
imagining up to five years now showing that the bio-resorption
time is about right in terms of maintaining the scaffolding
property for a sufficient amount of time, and yet allowing the
vessel to remain patent with nice property after that.
When I propose to use a bioresorbable vascular scaffold instead
of a metallic stent, patients like the idea. They like the strategy of
2. 019门诊 CLINIC
Physicians’Viewpoints 专家观点·东闻视野
being treated with an implant that will not be permanent. But the
next question is always: “When the scaffold is gone, will the stenosis
come again?” And the data available so far allow us to tell them that,
to the best of our current knowledge, “No, once the stenosis is been
resolved, the narrowing will not come back at that spot.”
Clinic: What will be the best material that is
capable to reach the balance between degradation
and scaffolding? Can BRS be extended to complex
lesions?
Dr. William Wijns: I think the balance between the
degradation through bioresorption and scaffolding properties
hinges more on the engineers and polymer scientists, for they
can probably design any time sequence, as you would like it be.
I don’t think it is the type of material itself that matters the most
but more the way you design and prepare it.
Currently, it takes two to three years for a BRS to disappear
completely. But it’s important to realize that the scaffolding
property is diminished as soon as the structure of the device
starts to dismantle, because we have to realize that the
scaffolding property only exists when the integrity of the device
is maintained. And the time when it starts to progressively loose
its scaffolding property is built in the devices by design, at least
that is what I remember from this very complex matter.
I think that your question was about the best material and you
asked this question from a perspective of bioresorption. But I
would turn it around and say that selection of the best material
is important for the late bioresorption for sure, but even more
so for the acute procedure. Can we improve on the scaffolding
properties of the bioresorbable devices to make them stronger
so that they can be used in more difficult lesions? We now have
over twenty years of device research; we now have very powerful
metallic thin struts, drug eluting stents. And our capacity to
deliver them in very complex lesions is amazing. For example,
we can treat bifurcation, CTO, small and large vessels. We
can overlap, combine and expand these metallic devices with
good results. Today, the properties of metallic devices have
not been completely taken over by the scaffolds. In a sense, the
current generation of scaffolds has not been as effective in its
deliverability, stenting capacity and plasticity to allow their use
in different anatomies as the extent metallic stents can be.
Although a metallic stent sounds very negative, it does a pretty
good job for us acutely and even in the longer term. So if you ask
a practitioner who has used lots of scaffolds ‘what is on the top
in his wish for improving scaffolds?’ I believe his answer will be
to improve on the acute properties of the device to make them as
effective as current drug-eluting metallic stents.
Clinic: Will it cause inflammation in the process of
degradation?
Dr. William Wijns: There had been a lot of work done on
bio-resorption of polymers in preclinical experiments, long
before clinical studies were performed. It was proven that if the
resorption was too fast early after the implantation, that would
cause inflammation.
Now the polymer science has become very sophisticated.
Progress in polymer science allows extension of the duration of
bio-resorption, but also improved blood- and tissue-compatibility
of the polymers being used. All these developments have led to
designing of devices that really do no longer seem to cause a lot
of concerns regarding excessive inflammation. And the present
anti-restenosis drugs not only prevent restenosis but also reduce
inflammation.
Clinic: In the experiences of your clinical
practices, what is the good patient eligible to be
implanted with a bioresorbable vascular scaffold?
Dr. William Wijns: The answer to this question will evolve
with time. At this moment, there may be situations of specific
lesions that you would like to treat with a scaffold, while the
current mechanical properties are not yet at a level where you
could use them with the same success as metallic stents. So as
better scaffolds become available, the answer to this question
will evolve.
Today let’s ask a hundred colleagues who have used BRS, “What
are the best indications?” Most often, young patients will be
3. 020 门诊 CLINIC
东闻视野·国际瞭望 outlook
Dr. William Wijns
Cardiovascular Center Aalst,
Belgium.
William Wijns, MD, PhD has been Co-
Director of the Cardiovascular Center
in Aalst, Belgium since 1994 and
active as an interventional cardiologist.
He has authored over 400 publications
in peer review journals and holds
several positions in national and
international professional and scientific
organizations, PCR in particular. His
research focused on the regulation
of coronary blood flow, cardiac
metabolism and imaging of ischemic
heart disease.
4. 021门诊 CLINIC
Physicians’Viewpoints 专家观点·东闻视野
listed first. We as cardiologists are not the only physicians to use
devices to a patient. The longer the patient life expectancy is,
the higher the likelihood is that this person will be treated with
permanent implants. Many of our elderly patients may have hip
prostheses, stents, a pacemaker, wires, and all sorts of permanent
implants. So if we can treat a coronary lesion with a nondurable
implant in a young patient, it may be of benefit in the long term.
Also, there are situations where the current metallic stents don’t
work well. And this is particularly the case when you have to
implant several stents over very long segments of the vessel. For
instance, what if we could open the CTO with a balloon, expand
the lumen and keep it patent with several scaffolds that would in
the end bioresorb. What about very long LAD lesions, we know
that if we implant two or three long metallic stents, we will be
closing the door for surgery or other interventions in the future,
especially if restenosis in the metallic stents occurs. And I could
go on with several conditions in which either you want to prevent
the patient from being implanted with a permanent device or you
want to improve the results of our current techniques.
Clinic: Can we anticipate the equivalent good
results in a bioresorbable scaffold with a metallic
stent, and what’s the prospective of BRS in future
with your eyesight?
Dr. William Wijns: It is quite relevant for the younger
generation of interventional cardiologists. I do not think that it is
unrealistic to state that bioresorbable scaffolds will be the stents
of the future.
However, I believe that the conversion process will take time.
And it is the same process that the metallic stent has gone
through. Today the use of a metallic stent in complex lesions is
rather simple, while it was not the case in the early days, at all.
The devices were bulky, difficult to deploy or placed on site.
At that time one needed to use covering sheaths, stiff wires or
double wire techniques, lesion preparation by balloon dilatation
or cutting balloons, etc. Does this sounds familiar?
My generation has gone through all these phases, so today we are
repeating the same cycle of the development through device iteration.
Now I think the younger generation of interventionists has to
learn the skills needed to bring the scaffolds on site safely. It does
take a learning phase in terms of preparing the lesions, using
the right guide catheter and wire combination, using the proper
inflation of deployment procedures, and using adequate post-
deployment scaffold expansion strategies. These techniques
are actually not too complicated, but are no longer routinely
needed with current metallic DES. It often requires more
time and use of more equipments to optimally deploy a BRS
scaffold than a BRS metallic stent.
I agree that the prospective of an equally good result after the
bioresorbable device disappears over time may justify the extra
effort. But the extra effort needs to be made in the first place if
we want the result to be equivalent.
The question is when will it happen? Is it today? Is it tomorrow,
or in five or ten years from now? I would like to guess it is
between five to ten years, simply because that will be the time
needed to develop scaffolds that perform as well in terms of
mechanical properties, as current metallic stents.
Today millions of patients worldwide have been implanted
and will continue to be treated with metallic drug eluting
stents. At the same time, the device industry will come up with
new iterations of existing devices, for instance thinner strut
BRS, or maybe totally different concepts. The magnesium
bioresorbable stents are under evaluation, and there is in China
very innovative research on the use of bioresorbable stents using
iron. With the current polymers or these different materials,
one day we may have an available scaffold that has very similar
mechanical properties to our best current metallic stent yet being
bioresorbable and will disappear over time.
Editor: Rahab Jin
7. 024 门诊 CLINIC
东闻视野·国际瞭望 outlook
Gregg W. Stone
M D, FAC C , F S C AI i s P ro fe s s o r
o f M e d i c i n e a t t h e C o l u m b i a
University Medical Center, Director of
Cardiovascular Research and Education
at the Center for Interventional Vascular
Therapy at New York-Presbyterian
Hospital, and Co-Director of Medical
R e se a rch a nd Ed u c ati o n at t h e
Cardiovascular Research Foundation in
New York, NY. Dr. Stone has authored
more than 2 0 0 0 bo ok chapters,
manuscripts and abstracts published
in the peer-reviewed literature, and
has delivered thousands of invited
lectures around the world. Dr. Stone,
along with Dr. Martin B. Leon, is the
director of Transcatheter Cardiovascular
Therapeutics (TCT), the world's largest
symposium devoted to interventional
cardiology and vascular medicine,
directs the annual National Interventional
Cardiology Fellow's Course, and co-
directs multiple other annual courses.
8. 025门诊 CLINIC
Physicians’Viewpoints 专家观点·东闻视野
What does a Brs Age Bring to Us?
Columbia University Medical Center Dr. Gregg W. Stone
There are many concepts on the future scaffold age of BRS. BRS will eventually take the whole place of DES
nowadays as the dominant strategy in clinical application of cardiovascular interventional therapy. And also, the
Co-Director of TCT, Dr. Gregg W. Stone from the Columbia University Medical Center, New York gave his
presentation of “BRS, the forth scaffold revolution” on the past 2015 CIT, completely disclosing the development
BRS has achieved thus far. While, BRS has proved its non-inferiority to DES in all existing clinical evidences
instead of attaining to benefits on a certain definite outcome. However, DES has definitely reduced and even
eliminated stent restenosis significantly in this scaffold age. Thus for the advent of a BRS age, what is the land-
mark of the clinical outcome benefit that BRS should arrive at to show its victory?
We were grateful to hold an exclusive interview with Dr. Gregg W. Stone in which he addressed this question
‘What does a BRS age bring to us? ’Additionally, we discussed the technical thresholds that the next generation
of BRS must overcome to enter the new scaffold age
clinic: what will be the best material for brs to
take the place of plla in the future?
Dr. Gregg W. Stone: There are two kinds of materials
that are being used for BRS, either polymers or metals, such as
magnesium and iron. And among the polymers, PLLA is very
safe since there has been a long history of using it. But it has
some limitations in terms of expansion, visibility, etc. And it is
also relatively soft, so it needs to be relatively thick, so it resists
recoil. That’s why there is interest in corrodible metals which
inherently are stronger than polymers, that being said there are
ways to modify PLLA to make it stronger and more flexible and
to allow it to expand further. And there are other polymers which
are visible, which is an advantage.
So I can’t say there is a single ideal material. PLLA will continue
to improve. Other companies will introduce new polymers, and
there will be certainly a lot of interest in corrodible metallic
stents especially magnesium, and possibly iron.
Clinic: Is it that ‘the thinner struts the
better’? How much thin minimally could it be?
Dr. Gregg W. Stone: Generally speaking, the thinner the
better in terms of more rapid endothelialization, and less likely
to compromise side branches. But as you got thinner, you also
lose mechanical strength. So we need to address the polymer and
/ or the design of the scaffold, thus we can maintain its radial
strength.
Regarding the minimum thickness of a strut, ~80 microns is
probably close to the limit.
Clinic: After the scaffolding property of a BRS is
completely vanished, do you agree to speed up its
resorption by medication?
Dr. Gregg W. Stone: There is a minimum duration of
scaffold that we need. And that’s probably between 9 to 12
9. 026 门诊 CLINIC
东闻视野·国际瞭望 outlook
months. Thereafter the scaffolding is less important, and we will
be happy if the scaffold goes away quickly. However, the faster
the scaffold resorbs, the more inflammation that might occur.
So there is a trade off the speed of the scaffold resorption with
safety. I don’t agree we will use medical therapy to speed it up.
My answer is no.
Clinic: Do we need to redo the DES studies with a
BRS?
Dr. Gregg W. Stone: Many of the studies we will need to
redo. BRS are very different than drug eluting stents. They offer
potential benefits for patients, but also they are somewhat more
difficult to use, and may have more procedural complications. So
most applications for drug eluting stents should be re-evaluated
in studies with BRS.
Clinic: DES age brings us the reducing of the stent
restenosis; what then does a BRS age mean to us?
Dr. Gregg W. Stone: Yes, DES have done very well at
reducing restenosis within the first year. But after the first year,
an ongoing number of events keep arising from the stent side for
many years. That’s either due to late polymer reactions or late
drug toxicity, or late strut fracture, or neoatherosclerosis. We
hope that BRS will reduce many of these late events.
BRS时代将为我们带来什么？
许多专家一致认同，未来是完全可降解支架（BRS）的时代——BRS终将全面取代药物洗脱支架（DES），
成为临床使用的主流支架。TCT联合主席、美国纽约哥伦比亚大学医学中心Gregg W. Stone教授在2015年CIT会
议上发表了“BRS，第四次支架革命”的演讲，全面介绍了目前BRS领域的进展。然而有一个未解的问题始终促
使我们思考，目前BRS获得相比DES具有非劣效性的试验结果，但还没有证实带来显著的临床终点获益。而相比
之下，DES确实降低甚至消除了支架内再狭窄的发生。因此，未来BRS胜过DES从而进入下一个支架时代，是否
同样需要取得标志性的终点获益？
带着这一疑问，《门诊》杂志邀约Gregg W. Stone教授接受专访，请他围绕“BRS时代对于临床究竟意味着什
么？”发表个人观点，并前瞻BRS技术未来的突破点。
美国哥伦比亚大学医学中心 Gregg W. Stone教授
《门诊》：未来是否会有一种材料比PLLA更适用于
BRS？这种材料可能是什么？
Gregg W. Stone教授：基本上，有两种材料适用于
BRS，聚合物和金属。金属主要是镁和铁。在聚合物中，长
期的临床实践已经验证，PLLA具有可靠的安全性，但其在
膨胀性能、可视性等方面存在局限。同时，聚合物材质相对
过于柔软，因此需要略微更厚，以防止支架回缩。
聚合物的不足使可降解医用金属材料在这一领域获得空
间。金属材料从本质上比聚合物更坚固，因此相比聚合物更
具有支撑力、灵活性，及可膨胀性。目前已经有一些可视的
聚合物，同样是具有优势的材料。
我无法断言会有某一种最为理想的材料。对PLLA的改
进不会止步。一些企业将会研发新一代的聚合物。同时可降
解金属首先是镁，其次可能是铁，将具有很大的可研发性。
Editor: Rahab Jin
11. 028 门诊 CLINIC
东闻视野·国际瞭望 outlook
Brs for the Future:
Not a Stent Generated, But a Coming Scaffold Age
Firstly, we must question what BRS is. Is it a name? A technology? Yes and no. Yes, it is either a name of a sort
of stent or a technology of interventional device. Yet it is much more than both of these.
And in 2015 CIT, the Director of EuroPCR, Dr. William Wijns (Cardiovascular Center Aalst, Belgium)
responded to Clinic interview, “I’m not taking a big risk saying that, bioresorbable scaffold will be the stent in
the future.” And it’s fair to say that over time drug eluting metallic scaffolds will be replaced by BRS, perhaps
in five or ten years, Dr. Wijns clarified in the end.
So now, editorialist tries filling the answer to the question surrounding BRS —— It is not a novel stent and
technology only used in future; it is the next age of scaffold before the next generation of cardiovascular
interventionists.
12. 029门诊 CLINIC
editorial 述评·东闻视野
Ⅰ. Endeavor in Breaking Barriers Step by Step
To predict what the future will hold, we need stands on today——
We realize that BRS still has a long way to come to achieve the
popularity of the pre-dominating stent——“And extra efforts must
be paid first if we want to see good results. Let us move forward
step by step.” Wijns concluded.
That’s true. We must go step by step to overcome all the technical
barriers that impeded the resorbable scaffold technology from
opening a totally new situation of interventional cardiovascular
practice. It is a pivotal hour to contribute to a speculation in the
field and in the BRS industry. BRS must make a real breakthrough
over time to usher into the highly anticipated BRS age.
A. Respect One: The Material
There are concerns raised in regards to the material of BRS. For
the future, the answer to the conflict between scaffolding and
degradation is mainly tied to the material of BRS. The first point
of concern is the optimized starting time for the dismantling to
start. Some have shared if the resorption could take place after the
first 3 to 6 months of the scaffolding after PCI, which leads to the
possible ideal issue of balance in between.
Furthermore, PLLA alone is for certain not adequate enough
to make up that material. Some extra explored elements for
example rare earth elements (REEs) which could be added to
enhance the scaffolding property of the stent. And there have
been some studies on the applicability of a metallic bioresorbable
scaffold, which is conducted by some device industrial enterprise
such as Biotronik. And a near reported issue will be brought
forth in 2015 from EuroPCR, which could be a breakthrough in
BRS material.
Last but not least, the material related conformability of a
resorbable scaffold is expected to be significantly more prioritized
over a metallic one. Thus, what is the best material that is
capable to meet all the above requirements? The interventional
cardiologists will continue their ongoing attempt to find out and
we will wait in anticipation..
B. Respect Two: The Profile
Although the material was first discussed, the profile of BRS is the
true matter at hand because the design of the profile will in some
sense directly determine the procedural complications and long-
term prognosis.
The biggest threshold we should conquer is commonly
acknowledged as the thickness of the struts. A thinner strut brings
higher feasibility, meaning it is appropriated to more complex
lesions in different situations. Also the Director of EuroPCR, Dr.
Jeans Fajadet (Clinique Pasteur, Toulouse, France) told Clinic
that 'The thinner the better”, he added, “we have to maintain
the good scaffolding capacity to stent the vessel during the first
three months.” So in future the topic for polymer chemist is
consequentially to target inventing thinner struts with the equally
strong scaffolding capacity. We will undoubtedly make it thinner,
but how much thinner minimally could it be designed? This open
question is highlighted here to all engineers to explore the correct
answer.
As resorbable scaffold can be completely dismantled in 2 or 3
years, it will not cause concerns of inflammation later. So the
next important threshold is accessing the engineering technique
of how to achieve the degradation time that enables a BRS to
dissolve in that designed period. Additionally, deliverability of
the scaffolds, and platforms etc. even the finest change in a small
aspect in profile design extends to procedural and post-procedural
application outcomes.
C. Respect Three: The Research
a. Future Directions
Medical science is laid on evidence. Research is the unique way in
which we arrive at the next landmark. For BRS to “move forward
step by step” to become the future dominant strategy in PCI,
it requires a vast array of researches and studies to make clear
what is currently unknown and realize what is known. It also is
deserving of discussion in regards to future directions for further
research, i.e. ,
to improve patient oriented outcome and vascular remodeling
/ regression after the procedure, to expand indications eligible
for BRS strategy Esp. category of complex lesions, to develop
the alternative material comprising new elements potentially
more satisfying than PLLA, and many more things. We are
commissioned to do this at this juncture as a privileged generation
13. 030 门诊 CLINIC
东闻视野·国际瞭望 outlook
who turn the ‘metallic permanent’ age to the ‘biological
resorbable’ age.
b. Extended Questions
Furthermore, two extended questions are raised and brought forth
to the rising generation of the cardiovascular world:
·When the age of BRS, whether the current results out from the
studies of DES observed today all have to be re-verified in studies
with a BRS?
·If we can affirm the scaffolding property of a BRS is completely
vanished via the imaging technology, is it a necessity to speed up
its resorption by some extra approaches such as medication?——
Since BRS is the future, namely, the dominant scaffold in PCI
strategy with permanent DES as second line therapy used by the
next younger generation of PCI interventional cardiologist.
Ⅱ. What does a BRS age mean?
A. A Meaningful DES Age
Tracing the story and history back of DES, when it was emerged,
it was the same under different attitudes. At the beginning, every
interventional cardiologist explored the indications and tried their
best to extend a DES unto every kind and the most difficult lesion
of the procedure. While, despite the first drug eluting stent being
approved in Europe with a CE Mark in 2002, DES already turns
the universally deployed stents in the hands of interventional
cardiologists worldwide. And in China, the rate of being implanted
a DES in patients undergoing PCI is up to 99.67% in 2014. This
story makes clear the undeniably remarkable DES age. What has
fundamentally led to its overwhelming BMS turning into a new
scaffold age was that DES significantly reduced stent restenosis.
B. Should BRS Have Its Merit?
By contrast, no matter porcine coronary models or human
clinical trials with a BRS until today stopped at proving its non-
inferiority compared to a DES. Hence, is it justified to enable
an epoch-making replacement with DES if BRS barely brings
the relief psychologically that the patient is not implanted with
a permanent cage? Or to say, it is also supposed to lead to the
clinical benefit in a certain definite outcome convincingly based
on adequate evidences, which substantially avails and contributes
to an ultimate consummation of a new victorious scaffold era. The
question arises then: ‘What may be this definite outcome in future
over time that appears a BRS benefits to clinic?’
Here we end with this prospective question——if today, a DES
age is a time we triumphantly drop the stent restenosis, what then
does the beginning of the BRS era mean to us.
Ⅲ. Home BRS Industry: ‘Created in China’
Dr. Gregg Stone in his interview has answered the questions
discussed in this editorial. Certainly, the topic of BRS is
constantly evolving. Its relation to China is specifically worthy of
our concern beyond the technologies category.
Thus far, with respect to our home industry, China maintains
the same pace as Western countries in terms of research work
in developing BRS technology. We look forward that to the
exploration China will see in the field and its contributions
to the world in BRS technologies by developing a countable
BRS device. We are confident in seeing the statement “Created
in China” as a very prideful addition in the cardiovascular
industry.
Clinic Editorialist: Rahab Jin
17. 034 门诊 CLINIC
东闻视野·国际瞭望 outlook
Commented by MD. yaojun Zhang：
In 1977, Andreas Grüntzig first introduced coronary angioplasty
as a treatment of obstructive coronary lesions and gave birth to
the speciality of interventional cardiology. Since then, the field of
interventional cardiology has developed very fast, with innovative
devices and technologies for coronary artery disease.
Bioresorbable scaffold (BRS) heralded as the fourth revolution
in interventional cardiology, offers the possibility of transient
scaffolding of the vessel to prevent acute closure and recoil. For
a BRS to be as effective as the currently available DES, it should
have an increased radial strength that should be maintained for
at least 6 months post device implantation and incorporate an
anti-proliferative drug that would control neointimal formation
and prevent restenosis. Eventually, there are no limitations
of permanent metallic implants in the coronary artery. Due to
attractive prospective, this new technology has been widely and
rapidly disseminated in the world.
To date, several BRSs were approved by CE, such as BVS
manufactured by Abbott Vascular, DESolve by Elixir Medical.
In China, 2 BRSs (NeoVas by Lepu Medical, Xinsorb by Huaan
biotechnology) has been developed and investigated clinically. I
do believe that more and more new BRS with special designs will
come, with improved radial strength, thinner strut thickness, etc.
Personally, I much expect to see some BRS with bioresorbable
metallic materials that provide a higher radial support and can be
used in more complex lesions.
For sure, the advent of BRS has also dramatically changed
coronary interventional practice. Recently, an expert consensus
endorsed by well experienced European interventionists has
been released. The invasive imaging modalities, such as optical
coherence tomography, have been recommended for guiding
scaffold implantation. Undoubtedly, special attentions should be
paid during the procedure. For example, the lesions must be well
prepared even with non-compliant balloon. Maximum scaffold
expansion limit is of 0.5 mm above its nominal diameter. Thus, do
not over-dilate the scaffold too much, which may result in scaffold
rupture and subsequently increase risk of stent thrombosis.
In terms of current regulatory requirements, I personally advocate
that some modifications should be taken. For example, setting up
an acceptable basic criteria on late lumen loss angiographically
instead of pursuing non-inferiority compared with metallic drug-
eluting stent (DES). Exact indications for special types of patients
and lesions should be added for approving a new scaffold at
least in this early stage. Also, critical evaluation of a new BRS is
essential, the preclinical and clinical studies not only investigate
safety and efficacy of the device, but also the evidence of
bioresorption of BRS with invasive imaging.
Finally, I have seen many of our Chinese manufactures go broad
recently, with their innovative technologies, such as Nano plus
polymer-free DES made by Lepu Medical, Firehawk groove-
filled biodegradable polymer DES made by MicroPort. Thus,
I also advocate our Chinese manufactures to invest this novel
BRS technology as soon as possible, and expect to see more safe
and effective BRS made in China which better improve clinical
outcomes in worldwide patients with coronary artery disease.
Editor: Rahab Jin
