Final Report
868 Cordis ARTS Deliverability Research
Study: Formative Ethnography Study
Date:
December 23, 2010
Originator: Sean Hägen, Mary Beth Privitera
Overview
Contents
Overview
Methodology
Objectives
Terms
Insights
Requirements
The following report summarizes an analysis of the Arterial Revascularization Therapies
Study (ARTS) ethnographic deliverability study. The study captured user preference
input in a double-blind, qualitative design research project to better understand
physicians’ current and ideal definition of stent “deliverability” and it’s associated system
attributes for percutaneous coronary intervention (PCI) stent delivery devices. The study
benchmarked user requirements to support the Cordis ARTS by visually mapping the
procedure in a static diagram poster and an interactive asset. The study methodology
included ethnographic research (contextual observation) of PCI procedures and brief
face-to-face interviews. The current respondent sample is summarized in Figure 1:
Personas
Interventions
Conclusions
#
Appendix
Total Case observed
Persona
Exp
Sites
Interview
PCI
Transrad
Femoral
Cases
Transrad
Femoral
1
Veteran
15
1
1
2
0
2
5
0
5
2
Common
2
1
1
1
0
1
2
0
2
3
Veteran
10
1
1
0
0
0
2
0
2
4
Common
6
1
1
2
2
0
2
2
0
5
Expert
19
2
1
2
2
0
3
3
0
6
Expert
17
2
1
0
0
0
2
2
0
7
Educator
30
3
1
1
0
1
4
1
3
8
Common
8
4
0
1
0
1
1
0
1
9
Veteran
8
4
1
0
0
0
1
1
0
10
Educator
9
4
1
0
0
0
3
1
2
11
Common
4
4
1
0
0
0
2
1
1
12
Veteran
19
5
1
0
0
0
1
1
0
13
Common
10
5
1
1
0
1
1
0
1
14
Expert
15
5
1
0
0
0
0
0
0
15
Veteran
31
5
1
0
0
0
0
0
0
16
Educator
17
6
1
1
0
1
3
0
3
17
Educator
20
7
1
1
0
1
1
0
1
#
Persona
Exp
Sites
Interview
PCI
Transrad
Femoral
Cases
Transrad
Femoral
7
16
12
4
8
33
12
21
17
Figure 1
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Methodology
The research methodology included contextual observation (ethnography) followed by
interviews utilizing a projective mapping exercise that captured the emotional
perspective of the primary users. The projective mapping exercise enables the
respondent to communicate visually by choosing from provided metaphoric images to
represent their experiences relative to a particular moment in time (step) during the
usage scenario. The respondent then explains why they chose the particular
photographic metaphor image which results in a story-telling opportunity in the interview.
The ethnographic observations serve as a source of questions for the subsequent
interview as well as providing unbiased contextual behavior as opposed to verbal
opinion. The protocol for the study may be referenced in the appendix.
The study included seven (7) sites, sixteen (16) interviews, thirty-three (33) diagnostic
procedures (12 transradial and 21 femoral approaches) of which 12 resulted in
interventions (4 transradial and 8 femoral – see Figure 1). During each site visit, a multichannel video approach was employed which simultaneously captured activity at both
the proximal and distal ends of the devices in use. The videos were synchronized during
post-production. Observations of the user’s focus of attention were also noted and
captured with still images. The site visits were concluded by interviewing users that were
digitally recorded. All data was documented (transcribed) for analysis and archiving.
Note that data (video, still photography, audio, etc.) excludes any patient specific
(identity) data in order to conform to HIPAA compliance requirements.
Objectives
► Map the PCI Usage Characteristics during the DES Delivery Steps
Characterize and codify the optimal stent delivery experience from the user’s
perspective, key current facilitators and barriers, and identify target design
criteria for successful delivery system development from device removal from
package to device disposal. Visualize the characteristics in a Procedure Map.
► Characterize User Sample
Identify and rank User Personas in order to augment the User Preference Inputs.
► Document User Preference Rationale
Capture how physicians define deliverability, what procedural factors influence it,
how it is measured, and ultimately, what are the attributes of a PCI-system that
enables optimal deliverability.
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Terms
Interviewer:
“During the selection
of devices are there
certain risk states or
anatomy situations
where you wish you
could use a stent, but
there’s just not one
that’s maneuverable
enough?”
Interviewee:
“Yeah. Mostly, that’s
the heavily calcified
lesions or the highly
tortuous vessels.
Those are the two
biggest areas where
you really have to try
to…”
- Veteran
The following terms highlight basic definitions derived from user interviews and
discussions in order to provide additional perspective and meaning towards inherent
product design implications and actionable product requirements.
Deliverability: A general term related to the use-scenario for advancing the stent
catheter along the guidewire to the target lesion and how readily this is accomplished
through to stent deployment. The term is interrelated with the definition of Tracking.
Trackability: A specific term used to describe the qualities of friction for either the
balloon or stent traversing the guidewire. The term is interrelated with Pushability.
Pushability: A specific term used to describe the firmness and/or device response from
the user’s manual input on the catheter and the device response at the distal end. The
term is counter to Flexibility.
Flexibility: A general term related to the ability of both wires and catheters to bend
around highly contoured and tortuous vasculature. The term is interrelated to
Deliverability and counter to Pushability.
Crossability: The amount of effort required for a guidewire and/or catheter to reach the
distal most portion of an artery beyond a target. The target may either be an untreated
lesion or a previously placed stent. The term is interrelated with Deliverability.
Insights
The following insights that drove the recommendations, conclusions and details
articulated in this report as well as the Procedure Map (both the static poster and the
interactive asset):
Set-up
1. There are three queuing areas for instruments and devices: non-sterile device
staging table (unopened packages), sterile instrument table, sterile draped patient
(legs and torso).
2. Devices are pulled from decentralized storage located within each cath lab suite
as well as centralized areas throughout the catheter lab ward on an “as needed”
basis throughout the procedure.
3. The non-sterile device staging table is intentionally visible by the Interventionist,
Assistant and Control Room Technician so that the unopened packages can be
ascertained if the Circulating Nurse is not in the room.
4. Other than introducing sheaths and preferred diagnostic catheter/guidewire for
initial assessment, not many other devices are prepared.
5. Physician and assistant (if used) are always on the patient’s right side. This does
not vary between user personas or sites visited. See figure below.
6. Typical set-up includes either a rotating hemostatic valve or 3-port mandrel for
Heparin/flush-Nitro access/contrast (see Figure 2).
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Insights continued
Figure 2
Stent Selection
1. Users may not vary stent brand within the same artery if an artery has a previously
placed stent (Physicians 1, 5, and 7).
2. Users base their decision on: initial training, previous stents, literature, use
experience, stents in which they haven't used in awhile (spread usage around due
to sales rep relationships).
“So, there’s
a. All stents are specifically picked for anatomical size and location (tortuosity
tortuosity, there’s
in access) requirements.
length, there’s a lot
b. Tortuosity and size are equal in importance in stent selection
of different criteria. A
c. The BMW wire is the most common initial selection
bifurcation lesion can
3. Time for decision varies dependent upon clinician: Decision not to stent is almost
be very complex
immediate for some e.g. some physicians determined the patient was not a good
because you might
stent candidate within seconds of diagnostic angiogram.
end up having the
4. Once they determine to “fix” (intervene), determining size requirements/stent
bifurcation stenting
characteristics for patient is at minimum 2-3x longer than initial diagnostic
or ejective stenting,
angiogram review.
things like that.”
5. The use of an IVUS system is more common with inexperienced users and/or is of
- Educator
routine practice for others during pre-dilation.
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Insights continued
Figure 3
Navigation & Deployment
1. The left hand typically stabilizes and guides the catheter into the sheath while the
right hand typically provides control/manipulation/pushing force (see Figure 3).
Interviewer:
a. This is true regardless of experience level and/or assistant vs. physician.
“Is that your preferred
b. The forefinger, middle finger and thumb are the primary digits used for
drug-eluting stent
the detailed motor control manipulation.
(Cypher) for
c. The user discerns subtle haptic feedback to understand torque, plaque
deliverability?
structure, tortuosity, disengagement from deployed stent, etc. through a
Interviewee:
pair of wet surgical gloves.
“No, it’s actually less
d. Significant coordination between the primary user and the assistant is
deliverable. That’s why
required to maintain sterility of the devices during preparation, insertion
I am saying that there
and withdrawal (see Figure 2).
might be some give
2. Puff injections (small amounts of contrast) are routinely used to re-inform the
and take in radial
user of the vascular road map.
strength and flexibility
a. A referential image is commonly used on one screen while advancement
and less deliverable.”
is observed on another.
- Educator
b. It is common that physicians have to adjust to different imaging systems
from suite to suite within a single cath lab.
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Insights continued
“Oh it's night and day. I
mean that Cypher is not
a really trackable device.
Um...it's -- it's much
more metal. And
uh...and it's -- and it's a
less flexible type of
metal. So I think it's -- it's
definitely hard to get
Cypher in places. That
was why Taxus became
the big stent.” – Veteran
“You need the compliant
3. In order to prevent the guidewire from moving, users will bring the stent catheter
down (towards patient’s leg) and subtly oscillate catheter during withdrawal.
a. In detail: “shake” to get catheter started in reverse then gently pull back
with fingers of their dominant hand keeping tension between hands. With
left hand maintaining control of the catheter at the entrance of the sheath.
Pull down slowly till balloon is in sight (outside patient) grab guidewire
with left hand while right hand continues to remove stent catheter.
b. Users want to preserve guidewire placement although stent has been
deployed.
4. Tracking along the guidewire, or lack thereof, can result in an exchange of
devices (e.g. the guidewire may be changed out, the buddy wire system
employed) and/or the stent catheter may be removed unused if tracking
becomes a formidable issue.
5. The initial Deployment: Atmospheric pressures and length of time vary widely
between patients and physicians; ranging between 10-15 atmospheres held for
15-30 seconds.
6. The performance characteristics (compliancy) for the stent deployment balloon
are not the same as those for post-dilation. It would be ideal if it were possible to
combine or change those characteristics (by the user) without having to
introduce an entirely new device.
7. The balloon and catheter getting caught on the stent during removal is a concern
(specific events noted from interviews were associated with the Taxus system).
balloon for the structure
and the non-compliant
balloon for the
deliverability.”
– Educator
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The following table is a compilation of brand preferences and associated comments by
the respondents:
Stent
Brand
Taxus
Boston
Scientific
 Trackability is good but less then
Xience (Veteran)
 Pretty good overall (Educator)
 Does not have a specific strength that
sets it better from any other stents
(Educator)
 Drug is too strong (Educator)
Promus
Boston
Scientific





No data
Cypher
Cordis
Nevo
Cordis
Endeavor
Medtronic
Driver
(bare metal)
Medtronic
Xience V
Abbott
Vacular
Pro Comments
Struts and thinner (Common)
Best delivery (Common)
Best pushability by far (Common)
Flexibility is good (Common)
Trackability is good (Veteran)
 Best data according to patient
outcomes, especially patients with
diabetes. (Common)
 Best radial Strength overall (Veteran)
 Higher radial strength than other
stents (Educator)
 Tracking is just as good as the Driver
(Educator)
 Flexibility is good (Educator)
 Unique design (Educator)
 Able to go through tortuous anatomy
(Educator)
 Drug delivery is good, polymer is
different than other stents because
after 90 days stent is a bare metal
(Educator - see transcript example
below) Note: usage not observed
 Flexibility and delivery is best
(Expert)
 Same stent platform as Driver but
has DES (Educator)
 Deliverable because of profile and
metal (Common)
 Crossability is best (Expert)
 Low profile makes it the best
(Veteran)
 Tracking is good (Educator)
 Flexibility and takes bends better
(Educator)
 Struts are thinner (Common)
 Maneuvers the best because of struts
(Educator)
 Drug Data and trackability is good
(Veteran)
 Overall restenosis rate is best
(Educator)
 Crossing profile is good (Educator)
 Good Data (Veteran)
 Profile is good (Common)
 Goes where you want it to go due to
low profile (Educator)
 Best data and good "work horse wire"
(Educator)
 Good Data and well develop
(Educator)
Con Comments
 Platform is the worst (Common)
 Not the best mechanically (Common)
 Stiffer stent and is not as easy to go
through calcium into tortuous vessels
(Common)
 Stiffer Stent causes difficulties for acute
bends(Expert)
 Not very good at trackability (Veteran)
 Stent has more metal and less flexible
(Veteran)
 Less flexible, less deliverable
(Educator)
No data
 Data says the stent is
more prone to restenosis (Educator)
No data
 Low Radial Strength (Educator)
 Issues traveling through highly
tortuous calcified arteries
when delivering (Educator)
Figure 4
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Insights continued
The following is an example of an interview transcript from Physician 7 commenting on
his preferred stent in Figure 4. Physician 7 is an Educator with 30 years of experience
preferring the transradial approach yet teaching the femoral approach as an entry level
practice (note, English is not the first language of Physician 7).
Interviewee:
Because one, this Nevo is unique, because it's built on Conor
technology, they make it extremely flexible.
Interviewer:
So, flexibility is...
Interviewee:
Deliverability, They make the stent very, very smooth...
Interviewer:
So, the flexibility comes into play when you are maneuvering through
torturous anatomy?
Interviewee:
reservoir
Torturous anatomy, right. And not only that, the Nevo they have a
Interviewer:
Oh, the way the drugs are in the stents?
Interviewee:
Yeah. They have reservoirs and this is typically the polymer and it
washes out in ninety days. After ninety days, you don’t have any more polymer left. So,
the polymer is the major offender now. What happens is you get the stent thrombosis,
that polymer is blamed for it. Because what happens, if this is your stent and this is the
vessel wall like that, this is at the beginning of the deployment, after two years the
anatomy changes. This is the stent and this is the vessel wall – you will get a big
aneurysm and separation of the medial – this is the medial – you get separation of the
medial from the stent and basically this is free floating area and blood flows here and the
patient starts Plavix and they get central thrombosis, but the polymer is gone in ninety
days and that’s big advantage that you don’t have polymer anymore. So, this is going to
be a winner here; it's 1) flexible, 2) is deliverable, and 3) has a polymer which is gone in
ninety days. After ninety days the stent is bare metal stent…
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Requirements
“Because, in my
opinion they have the
best data according
to patient outcomes,
especially in patients
The following usability requirements (per the Cypher PD) address the entire user
experience from unpacking the system to withdraw after deployment (detailed in the
Procedure Map). The original requirement copy is in italics. An evaluation of each
requirement is provided discussing observed behavior and compiled opinion. Finally a
recommendation is provided to indicate where, if appropriate, the users experience may
be enhanced with further design considerations.
with diabetes.”
– Common
Interventionist
“If it’s something that
I think will be
demanding of radial
strength, I'll tend to
still use the Cypher
or something. I think
Cypher probably has
the most radial
strength”
– Veteran
1. It should be easily removed from its packaging without significant risk of damage to
the product.
a. Current packaging design meets this need, however, when the sterile bag is
opened the contents are often dropped on the instrument table and therefore
if the packaging is round it has the risk of rolling off the table.
b. Recommend: Inner packaging tray geometry shall not be capable of rolling.
2. It should be easy to prepare and flush prior to use.
a. Preparation and flushing of the stent catheter is primarily completed by an
assistant (tech or fellow) during this task the attending will coach them on
technique for insuring sterility (e.g. monitoring both ends of the device, how to
coil it for immersion in the saline bath, etc).
b. Observed challenges include threading stent catheter on guidewire in the
inconsistently illuminated alignment conditions.
c. Recommend: consider packaging tray that also functions as a “bird bath” for
use in the flushing process
3. The user requires product that is easy to handle and will not easily damage,
beginning with removal from packaging through actual use with dim lighting and
readily accessible preparation equipment (syringes, stopcocks, etc).
a. This requirement is redundant to requirement #1; in both instances the
definition of damage is not defined.
b. Damage is commonly communicated by users as those actions/manipulations
that results in inadvertent kinks in the guidewire and/or guide catheter. Kinks
in these tools may require a device exchange resulting in increased overall
procedure time as well as an increase in expense to patient.
c. Recommend: Focus a unique requirement on potential damage for each
phase of use: preparation, advancing-deployment, and withdrawal.
4. During use, it should be designed such that it is easy to maneuver: advance and
retract through the guiding catheter and over the guide wire.
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a. Ease of maneuver, advancement and retraction can be broken into 4 distinct
phases or steps: threading/loading onto guidewire, navigate stent catheter
towards target lesion, deployment and removal/withdrawal.
b. Users interact with the stent catheter differently for each phase:
i. Threading: fine motor control with precise hand-eye coordination
which can be accomplished as a team (physician and assistant) or
independently to insure the entire device does not inadvertently exit
the sterile field.
ii. Navigation towards/through lesion: intermittent pushing motions
whereby non-dominant hand serves as a stabilizer guiding the stent
catheter within the guide catheter while the dominant hand completes
the majority of pushing motion. These motions are generally swift and
confident through the aorta to the distal edge of the guide catheter.
Once advancement to the target lesion has been grossly achieved,
users complete more subtle small micro-motions with the forefinger,
middle finger and thumb of their dominant hand to finesse stent
device into final placement. Two disparate forms of feedback guide
the clinician: haptic (sense of touch specific to the resistance of the
devices within the anatomy) and visual (much of the visual feedback
is not in real-time and requires cognitive mapping due to the nature of
fluoroscopy, i.e., maximum dosage of contrast agent).
c. Deployment: Adherence to the IFU regarding inflation pressure/duration are
subject to context and technique.
d. Removal/Withdrawal: Rate and oscillation varies depending on users and
phase of the procedure (e.g. exchange catheter vs. closure).
i. The haptic perception that the balloon/catheter is catching on the stent
during removal is a constant concern.
ii. Guidewire position preservation for exchanges during the procedure is
critical. Observed techniques to maintain position include pulling the
catheter down (towards patient bed) at a steep angle then using quick
fine oscillating motions as the catheter is removed.
iii. Removing the guide catheter too quickly upon final withdrawal may
result in a “whipping” effect that can compromise wound closure.
e. Recommend: Focus a unique requirement on ease-of-use for each phase of
use: preparation, advancing/navigation, deployment, and withdrawal.
Consider haptic biomechanical capabilities of the user (wearing surgical
gloves) when developing and testing delivery systems (e.g., ungloved finger
sensitivity is capable of discerning micron level texture changes)
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5. The stent will be visible such that accurate placement will be possible (e.g., crossing,
sizing, dilation, overlapping, confirmation).
a. For accurate placement of the stent users can readily see the stent but rely
heavily on a mental map of the vessel roadmap to navigate positioning.
b. IVUS is typically used for accurate sizing and prediction of dilation response
either as routine practice or to inform decisions.
c. Recommend: no change to this requirement, however, IVUS compatibility
should be accommodated and may require a modification and/or additional
requirement.
6. The stent and delivery system will be designed such that delivery through distal and
tortuous vessels will be possible.
a. Delivering to distal vessels remains a challenge as verbalized in interviews.
Users refer to the definition of distal vessels as the delivery of a stent at the
farthest most point reachable along the guidewire as well as the ability to
deliver a stent distal from a previously placed stent.
b. Tortuosity also remains a challenge. Users define tortuosity as the natural
three dimensional curvature course of the anatomy. In extreme cases this is
observed as a corkscrew formation traversing considerable vasculature
length. Users note the change in natural shape as a result of accessplacement e.g. anatomy straightens when stent is deployed. While this is not
necessarily problematic, clinically, users perceive this as a considerable
change. Considering the Hippocratic creed of “do no harm”, this represents
an opportunity for stents to better conform to the natural anatomic geometry.
c. This requirement does not address the additional challenge of the users to
cross heavily calcified regions.
d. Recommendation: Requirement should consider individual elements within
each condition – distal vessel, tortuosity and calcification and revise
accordingly.
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Personas
The following stereotypes generalize the personalities of the typical user population
observed during the study. The intention of these generalizations is to codify user types
so that performance expectations can be prioritized by user group.
Expert
 A key opinion leader; a Veteran that has performed over 200 PCI procedures a
year, upwards to 400 per year
 Extremely self-confident; highly involved in the interventional cardiac community
 Enjoys a challenging case (minor complications or torturous anatomy)
 Works with a consistent team
 Has a very strong ego, respected by staff and colleagues
 Advocates his optimized procedural techniques and has strong opinions
 Less interested in minor advancements to devices/procedure
 Leads research to develop devices/techniques to match his protocols
 Has seen it all and claims to not be challenged or anxious
 Is easily frustrated by device deficiency and impatient with new technology
Educator
 A Veteran or Expert who has additional academic responsibilities such as
fellowship training and/or clinical research
 Level of case volume varies due to teaching responsibilities but typically performs
over 200 PCI procedures per year
 Highly enthusiastic, contributes to the greater good of healthcare
 Enjoys discussing the benefits and techniques of the procedure
 Open to experimenting with new devices and techniques
 A good listener who enjoys problem-solving and helping others
 A team player, but has an inconsistent team; typically has a fellow as an assistant
 Open to try new technologies and is patient with minor device iterations
Veteran
 Performs over 200 PCI cases per year
 Enjoys telling others about the benefits and techniques of the procedure
 Very confident in his technique, yet often modest and open to optimization
 Loves a challenging case (minor complications)
 Comfortable with current procedure; willing to try new protocols that promise to
advance patient outcome/business case
 Is focused on throughput and volume of procedures per year
 Techniques are optimized – systematic/repeatable work flow
 Frustrated when issues during procedure cause delays
 Impatient with technology unless an early adopter (function of demographic)
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Personas continued
Common Interventionist
 Performs fewer than 200, PCI procedures per year
 Frustrated with most complications
 Very cautious about device selection and protocol to prevent complications
 Eager to learn new ideas, techniques, and devices, but follows the lead of a
mentor – highly influenced by opinion leaders
 Is familiar with the entire procedure and performs the procedure in the same
manner following same steps and approach each time – has not developed
techniques beyond original training
 Little variance in procedural practice unless confronted with complications
Conclusions
“It’s planning based
on risk of the lesion
in the sense of
sometimes, if you got
a heavily calcified
lesion, there’s the
risk in the sense of it
being a very difficult
and is it likely to be a
successful
intervention. But
then also a risk, in
the sense that if it’s a
bifurcation lesion, is it
high risk ’cause
you’re gonna close
In the past stent delivery systems were expected to enable interventionists to treat
lesions in vessels that were readily accessible. As technology improved and the design
of the systems was optimized within the constraints of currently utilized materials and
processes, the systems have become commoditized. This is evident in the fact that no
one manufacturer “owns” the entire procedure (providing a kit that includes all the
primary devices need for stent delivery) from one lab to the next. Developing a system
of devices that would enable Cordis to be the primary brand for PCI procedures within
an institution is a strategic opportunity.
The physicians’ skills and techniques have also evolved to optimize the current product
offerings. The result is a changing definition of what a “readily accessible lesion” means
according to the physicians. The really challenging cases where deliverability is
significantly tested (e.g., bifurcations, crossing an existing stent, smaller vasculature,
etc) are becoming more common and place more demand on the performance
requirements of future stent delivery system development. Utilizing this insight to drive
an intervention system that starts at the sheath introducer and ends with a post dilation
device could change the paradigm.
down a side branch
that you’re crossing.”
- Veteran
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Conclusions continued
The following list summarizes the trends identified so far during this study:

“The compliance of the
balloon that a system is

Pre-dilation occurs 75% of cases (N=12).

Preferred approach (radial vs. femoral) has no influence on stent choice.

The domestic occurrence of the transradial approach is becoming significantly
more common than previous study 5 years ago (from 15% to 30%; N=12 of Rx
cases; 36%; N=33 of Dx).

Xience is the preferred brand of stent based on deliverability.
I have to, once I have to
that what I prefer over a
to be a bit stiffer about
getting around bends. Of
course, will be knowing
the data or restenosis.”
- Expert
Navigating a wire through the struts of an existing stent into a bifurcation
is a difficult challenge.
A means to visualize the extent to which two over-lapping stents are engaged
would be useful.
going to be bigger. So if
compliant, you’re going
o

need a 3.0, I think it’s
stent that is non-
Bifurcations and existing stent location are also challenges requiring
higher performance of the stent delivery system.
Use of marker wire varies and is experience/preference/imaging equipment
driven; commonly used but less often by the more experienced (current marker
spacing is sufficient; those that use a variety of imaging equipment use them
more often due to inconsistence magnification).
talked earlier about.
non compliant balloon. A
o

compliant balloon, we
it into to go up higher so
Selecting the appropriate guidewire to provide adequate support
traversing the lesion is directly correlates to procedural success.
The interventionist has to be able to discern subtle haptic feedback to
understand torque, plaque structure, tortuosity, disengagement from stent, etc.
with the forefinger, middle finger and thumb through a pair of wet surgical gloves.
These criteria should be accounted for during bench-top testing (new device
design and development).
like a little bit more
see it and dilate and look
o

on, I tend to personally
Sometimes thinking I will
Tortuosity and calcification are the most difficult challenges.
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o
Preference is based upon deliverability specifically communicated as thin
struts/low profile as well as complimentary available data (demonstrated
success in published literature).
o
Cypher is used because of the data available for the pharmaceutical
outcome despite an acknowledged deficiency in the deliverability relative
to the Xience system (5 comments in 14 interviews; Figure 2).
o
Radial strength is perceived to be better in the Cypher than the Xience by
those that use the Xience yet they choose to sacrifice that attribute in
exchange for better deliverability.
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Appendix
ARTS Protocol
868_ARTS Protocol_082610.doc
Discussion Guide
868_Discussion Guide_071410.doc
Interview Data
868_Interview Data_120810_r1.xls
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