Transcript Is There Still a Controversy About Stent Type for TASC C&D Lesions? Insights From COBEST Randomized Trial Aravinda Nanjundappa, MD, FACC, FSCAI Associate Professor of Medicine.

Is There Still a Controversy
About Stent Type for TASC
C&D Lesions?
Insights From COBEST
Randomized Trial
Aravinda Nanjundappa, MD, FACC, FSCAI
Associate Professor of Medicine and Surgery
West Virginia University
Charleston, WV
Claudication treatment options
•Treatment
Exercise
Angioplasty
Surgery
Cilostazol
Benefit
QOL
100%
50-100%
150%
50%
↑↑
↑
↑↑
↑
Limitation
Not available
Distal lesions
2-5% risk
Not in CHF
Claudication treatment options
•Treatment
Exercise
Mechanism
TASC II
Metabolic,
Walking efficiency
Endothelial
A
Angioplasty
Hemodynamic
A
Cilostazol
Metabolic,
Hemodynamic
Vascular smooth muscle
A
Results of Iliac Angioplasty
Gruntzig (1979)
Two to Four Year Patency
Schwarten
(1984)
100
Kumpe (1982)
95
70
82%
4 Year
75
87%
3 Year
80
82%
2 Year
85
Gallino (1982)
89
%
2 Year
%
87
%
2 Year
90
Spence (1981)
Results of Iliac Angioplasty
Late Clinical Succes
64.9
70
60
59.7 56.7
53.4
10
0
5 Years
4 Years
30
3 Years
40
2 Years
50
20
Ann Surg 1987;206:403-13
75.2
1 Year
• 667 iliac
procedures
analyzed
• One month clinical
success 90.2%
%
80
Stenting of Iliac Arteries
Multicenter Experience
Effect on Clinical Stage
80
70
60
50
% 40
30
20
10
0
Before Treatment
Stage 0
Stage I
Stage II
Stage III
Stage IV
After Treatment
Cardiovasc Intervent Radiol 1992;15:29
Stenting of Iliac Arteries
Multicenter Experience
•
•
•
•
•
587 procedures in 486 patients.
1.9 ± 1.3 stents per patient (1 - 8).
405 patients - unilateral stents.
81 patients - bilateral stents.
Mean follow-up: 13.3 ± 11 months (1 48).
• 201 patients underwent angiographic
follow-up at 8.7 ± 5.7 months.
Cardiovasc Intervent Radiol 1992;15:29
Stenting of Iliac Arteries
Multicenter Experience
• Angiographic patency (defined as <
50% stenosis within stent): 92%
• Sustained clinical benefit:
– 90.9% at 1 year
– 84.1% at 2 years
– 68.6% at 43 months
• Diabetes and poor run off had a
negative influence on the clinical
outcome
Four Year Patency
Critical Limb Ischemia
80
70
60
50
40
30
20
10
0
67
53
53
44
PTA
Stenosis
Occlusion
STENT
Radiology 1997;204:87-96
Four Year Patency
Claudication
90
80
70
60
50
40
30
20
10
0
77
65
54
61
Stenosis
Occlusion
PTA
STENT
Radiology 1997;204:87-96
PTA vs. Stenting For Aortoiliac
Occlusive Disease
• Meta-analysis of 6 PTA studies (1,300
patients) and 8 stent studies (816
patients)
• Immediate technical success:
– PTA
– Stent
91%
96%
P < 0.05
• Risk of long-term failure reduced by 39%
after stenting
Radiology 1997;204:87-9
% Luminal Narrowing
Randomized Trial:
Mean Restenosis
60
50
40
30
14
20
10
19
12
27
23
15
14
Stent
PTA
6
0
Immediate
6 Months
12 Months
24 Months
G. Richter et al, 1992
Express® LD Iliac Premounted Stent
System, MELODIE Trial - Overview
• Trial Design:
A prospective, multi-center, single arm study to obtain additional
data on the safety and efficacy of the Express™ LD Stent
implantation in the treatment of stenosed or occlusive
atherosclerotic disease (de novo or restenotic) in iliac arteries
(common and/or external).
• Objective:
The objective was to demonstrate non-inferiority of the Express™ LD
Stent for the treatment of atherosclerotic iliac artery lesions as
compared to an objective performance criterion* (OPC), with a primary
endpoint of mean percent luminal diameter loss at 6 months.
• Enrollment:
151 patients (163 lesions) with de novo or restenotic
atherosclerotic lesions <100mm long in vessels between 5 and
10 mm in diameter with stenosis > 50%.
*Objective Performance Criterion An objective performance criterion (OPC) is a benchmark used to compare a trial’s results against a literature derived control
group. For the MELODIE study the objective performance criterion was constructed from the Palmaz® Balloon Expandable Stent iliac study, Cardiovasc
Intervent Radiol 15: 291-297, 1992, and was defined as 15% mean percent luminal diameter loss at 6 months.
Palmaz is a trademark of Johnson and Johnson.
90541175
Express® LD Iliac Premounted Stent System
MELODIE Trial – TLR
12
10.2
9.0
10
8
6.3
6
TLR%
4
2
0
6 Months
1 Year
2 Years
90541175
Role of covered stents
• Several studies have demonstrated that
PTFE covered stents may provide better
results as compared to bare metal stents,
particularly in TASC C and D lesions.
• Chang, et al demonstrated that covered
stents show a significantly higher patency
rate long term (at 5 years) as compared to
bare metal stents when used to treat TASC
C & D iliac lesions (87% vs. 53% p≤.01)6.
Covered stents
• Of note, the covered stent lesion
characteristics were statistically more
advanced than those in the bare metal
group (38% of covered stent group had
type C & D lesions versus 7% for BMS
p=0.034).
• The covered stent group had superior
outcomes, regardless of the type of
lesions treated
TASC II aorto-iliac lesions
Type C and Type D
Atrium’s Bx Covered Stents
Advanta™ V12 and iCAST™
iCAST is FDA approved for the treatment of tracheobronchial strictures. Advanta V12 is CE approved for
restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only)
Atrium’s FilmCast™
Encapsulation Technology
Stent type
Length
Uncoated corrugated ring (28 day)
72±23
ePTFE+corrugated ring (28 day)
18±03*
Uncoated slotted tube (28 day)
93±16
ePTFE+slotted tube (28 day)
17±04***
Neointimal (µm)
ePTFE+slotted tube (56 day)
13±02
BMS
at 28
days
* P<0.007 compared to uncoated corrugated ring
**P<0.0001 compared to uncoated slotted tube
Rogers, C & E. Edelman. A Non-GLP Study of Biologic Responses to Uncoated
and PTFE Coated Steel Stents in Rabbit Iliac Arteries. (1997)
Covered
Stent
at 28 days
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
COBEST Trial
What is COBEST: (Covered Balloon Expandable Stent Trial)
• A prospective, randomized, controlled, multi-center (12 sites) clinical trial
comparing Atrium’s balloon expandable covered stent to bare metal stents
for use in iliac occlusive disease.
Inclusion criteria:
• Type B, C, or D lesions.
• Dissection after angioplasty.
• Recurrent stenosis after angioplasty.
Follow up:
• Patients were followed clinically (with ABI and symptom relief) and by
duplex US scan at 6, 12, and 18 months.
Primary Objective:
• Binary restenosis (<50% stenosis on DU/Angiogram)=primary
patency at 6, 12 and 18 months.
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
COBEST Trial-18 Month Results
Atrium’s covered stent technology is superior to bare metal stents for iliac
occlusive disease.
• V12 showed lower binary restenosis rates (p=0.037).
• Binary restenosis defined as vessel patency <50%
• This proves the V12 offers higher patency than bare metal stents
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
COBEST Trial-18 Month Results
•
V12 group experienced the greatest improvement in Type C & D lesions
• These findings are highly statistically significant (p<.002)
• V12 outperforms bare metal stents with more challenging C & D lesions
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
COBEST Trial-18 Month Results
V12 showed significantly lower target lesion revascularization Rates (TLR)
•If the patient received a bare metal stent, they were 5X more likely to need a reintervention
•This is a huge burden on a patients quality of life and an enormous economic impact on
the overall health system
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
Outcomes of Kissing Covered Stents Compared to Non-Covered Stents
for Aortic Bifurcation Lesions
Objective:
•
•
•
Retrospective review
Kissing Stents for aorto-iliac lesions
Compared bare metal stents to covered stents
Methods:
•
•
26 patients received Atrium covered stents
28 patients received bare metal stents
–
•
•
17 patients with Palmaz Genesis (Cordis) and 11 patients with Express LD (BS)
Median follow up was 21 months
– 25 months for the non covered stent group
– 20 months for the covered stent group
Indications for stent placement included claudication and limb-threatening
ischemia.
iCAST is FDA approved for the Sabri SS, Angle JF, Choudrhi AF, Dake MD
Journal of Vascular and Interventional Radiology July 2010 treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
Outcomes of Kissing Covered Stents Compared to Non-Covered
Stents for Aortic Bifurcation Lesions
Results:
• Treated lesion characteristics were statistically more advanced in
the patients with covered stents:
– 38% of Atrium covered stent patients had type C & D lesions
(p=0.034)
– 7% of BMS patients had type C lesions
– 0% of BMS patients had type D lesions
– 92% of BMS patients had simple type A & B lesions
• Technical success was achieved in 100% in both groups.
• Primary patency rates at 1 & 2 years:
– Bare Metal Stents = 78% and 62%
– iCAST covered stents = 92% and 92% (p value = 0.023)
• ABI’s at follow up:
– Covered stent group- increased from 0.74/0.61 (right/left) to
0.80/0.88
– Bare metal stent group-decreased from 0.77/0.070 (right/left) to
0.74/0.79
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
Outcomes of Kissing Covered Stents Compared to Non-Covered
Stents for Aortic Bifurcation Lesions
Results Continued:
•
•
Sustained clinical improvement at follow up:
– 85% of Atrium covered stent patients had sustained clinical
symptom improvement during follow up period.
– 54% of BMS patients had sustained clinical symptom improvement
TVR at 2 years:
– Atrium Covered Stent = 8%
– BMS = 38 %
Conclusion:
– There is a clinically and statistically significant difference in the
patency rates of balloon expandable covered versus bare metal
balloon expandable stents employed in the treatment of
atherosclerotic occlusive disease of the aortic bifurcation and
proximal CIA’s.
iCAST is FDA approved for the treatment of tracheobronchial strictures.
Advanta V12 is CE approved for restoring the patency of iliac and renal arteries (renal approval is for 5-7mm sizes only).
iCARUS Trial
What is iCARUS?
• Atrium iCAST Iliac Stent Trial
• IDE trial to support a PMA application
Objective:
• To evaluate the iCAST covered stent for treating iliac
artery stenosis (as compared to other FDA approved iliac
stents) in patients with de novo or restenotic lesions in the
common and/or external iliac arteries.
iCARUS Trial
Study design:
• Prospective, multi-center, non-randomized, single arm
registry
Primary endpoint:
• A composite endpoint defined as:
• Occurrence of death with 30 days,
• Target site revascularization or
• Restenois within 9 months post-procedure
iCARUS Trial
Secondary Endpoints:
• MAVE
• MAE
• Device Success
• Acute Procedural Success
• Clinical Success
• Patency
• Composite rate of 30 day death, 9-month target site
revascularization and 9 month restenosis in subjects without
total occlusions of the iliac
iCARUS Trial
• Clinical sites:
• 25 sites in the US
• 1 international site
• 165 Patients enrolled
• Enrollment:
• Completed in October 2010
• 9 month follow up
• Last patient scheduled for 9 month
• follow up in July 2011
• PMA submission by end of 2011
Conclusions
• Covered stents are safe, less TVR and
less re stenosis for patients with TASC
C and D lesions
• Results of iCARUS are awaited
• Cost benefit ratio of covered stent
versus BMS: Less TVR and less
readmissions
•