03:15 pm – 03:30 pm
Lecture: Bioresorbable vascular scaffolding (BVS) in clinical
practice: what can we expect after CE Mark?
Raul Moreno
University Hospital La Paz
Madrid, Spain
Bioresorbable vascular scaffolding (BVS)
START randomized study (n=452)
Long-term follow-up
8-June-2011
The benefit of BMS is
within the first months.
Is there any advantage of a
permanent scaffolding?
And any disadvantage?
Mechanical support is
needed to avoid negative
remodeling and vessel
shrinkage, that occur
during the first 6 mo.
JACC 1999;34;1498-1506.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Long-term safety problems of coronary stents
Two Patients with Extremely Late (8 and 12 Years) Bare-Metal Stent
Thrombosis: The Risk Never Completely Disappears!
J Invasive Cardiol 2008;20:E329-330.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
The problem of VLST is more evident with DES
Am J Med 2006;119:1056-1061.
J Am Coll Cardiol 2008;52:1134-1140.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Is there a need for bioabsorbable stents?
Potential advantages of bioasborbable stents
• Risk of stent thrombosis never completely dissapears.
• Need for indefinite anti-platelet therapy.
• Potential limitation for future CABG.
• Stent fracture.
• Prevent late stent malapposition & allow positive remodeling.
Stent in thrombus containing lesions.
• Side branch compromise in bifurcations.
• Bifurcations: Long-term safety issues of 2-stent techniques.
• Aorto-ostial lesions.
• Concerns about endothelial function.
• PCI in children.
• IRM & MSC imaging.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Previous bioabsorbable stents
REVA
1,2
Late loss
(mm)
AG 1.42; LL 1.08 mm
PROGRESS-AMS
Late loss (4 months):
• 42% vessel shrinkage
• 45% hyperplasia
Too quick absortion
1
AG 1.81; LL .1.89 mm
LL: NIH & loss of stent area
Net gain = 1
Mg
BMS
0,8
DREAMS
AG 1.44; LL 0.68 mm
BIOSOLVE-1
0,6
0,4
BA
PES
0,2
SES
EES
Acute gain
(mm)
0
1
1,1
1,2
Lancet 2007;369:1869
1,3
1,4
1,5
PCR 2011
1,6
1,7
1,8
1,9
TCT 2009 & TCT 2010
2
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Polylactic acid
L-LA
*Polymer: a large molecule
(macromolecule) composed of
repeating structural units.
D-LA
Meso L,D-LA
Lactic Acid
(C3H6O3)
Racemic D,L-LA
~LA~LA~LA~LA~LA~LA~
CO2
&
H2O
J Exp Biol 2005;208:4561
Poly-lactic acid
- Poly-L-LA (PLLA).
- Poly-D,L-LA (PDLLA).
- etc.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
REVA
1,2
Late loss
(mm)
Net gain = 1
Mg
1
BMS
0,8
DREAMS
Tamai
(PLLA)
AG 1.57; LL .75 mm
LL: neo-intimal hyperplasia
0,6
0,4
BA
PES
0,2
SES
EES
0
1
1,1
1,2
1,3
Circulation 2000;102:399
1,4
1,5
1,6
1,7
1,8
1,9
2
TCT 2009 & TCT 2010
Acute gain
(mm)
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Lessons:
• Acute gain should be optimal (radial strength).
• Absorption should not be too quick.
• Neo-intimal hyperplasia occurs: release anti-proliferative drugs.
BVS (Abbott vascular)
• Polymer backbone (PLLA) Semicrystalline
• Polymer (PDLLA) and everolimus matrix. Amorphous
Bioresorbable vascular scaffolding (BVS)
8-June-2011
ABSORB (Cohort A)
(30 patients treated with 3x12 or 3x18 mm BVS)
• Clinical FU (4 yr): 1 NQMI, 2 non-cardiac deaths, no ST.
• OCT: resorption begins at 6 mo, almost complete at 2 yr.
6 mo. IVUS: reasons for late loss
BMS
EES
BVS
Late loss (mm)
0.87
0.10
0.44
Ʌ Stent area (%)
-2.0
-0.3
-11.2
Ʌ Lumen area (%)
-29.4
-7.2
-16.6
NIH area (mm2)
1.98
0.50
0.30
Shrinkage (“late recoil”)
… that does not continue
from 6 mo. to 2 yr (!!)
*EES and BMS provided by SPIRIT-I
NCT00300131
Eurointervention 2005;1:58-65
Lancet 2008;371:899-907
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Second generation BVS
• Same composition, dose of everolimus & resorption time.
• Same strut thickness (150 µm).
• Modified platform designed with a reduced maximal circular
unsupported scaffold area (MCUSA) and a different manufacturing
process of the polymer.
• More uniform strut distribution.
• Similar profile to a 1st-generation DES:
Profile
Strut thickness (µm)
BVS 1.1
Cypher Select
1.40
1.23
158 (150 + 6-8 polymer)
164 (140 + 24 polymer)
Bioresorbable vascular scaffolding (BVS)
8-June-2011
ABSORB (Cohort B)
n = 101 (3x18 mm stents)
Current data: up to 1 year no deaths, no QMI, no stent thrombosis
BMS
EES
BVS
BVS 1.1
Late loss (mm)
0.87
0.10
0.44
0.19
Ʌ Stent area (%)
-2.0
-0.3
-11.2
-2.0
Ʌ Lumen area (%)
-29.4
-7.2
-16.6
-5.4
NIH area (mm2)
1.98
0.50
0.30
0.08
*EES and BMS provided by SPIRIT-I
TCT 2010
NCT00856856
PCR 2011
Bioresorbable vascular scaffolding (BVS)
8-June-2011
REVA
1,2
Late loss
(mm) 1
Net gain = 1
Mg
BMS
0,8
DREAMS
Tamai
(PLLA)
0,6
BVS-1
0,4
AG 1.24; LL .44 mm
Lancet 2008;371:899
BA
PES
0,2
BVS-2
AG 1.26; LL .19 mm
TCT 2010
SES
EES
Acute gain
(mm)
0
1
1,1
1,2
1,3
1,4
1,5
1,6
1,7
1,8
1,9
2
Bioresorbable vascular scaffolding (BVS)
ONGOING & FUTURE TRIALS:
■ ABSORB Extend: ~ 1,000 patients, 100 centers. Single arm.
No angio. follow-up (clinical end-points).
Preliminary data
No episodes of stent thrombosis
months
■ ABSORB Randomized study: ~ 500 patients. RCT vs Xience.
Angio follow-up.
8-June-2011
Bioresorbable vascular scaffolding (BVS)
8-June-2011
Abbott Receives CE Mark Approval for World's
First Drug Eluting Bioresorbable Vascular Scaffold for
Treatment of Coronary Artery Disease
What
when I
had BVS
in my cath.
Lab?
• STRENGTH: No permanent device.
• WEAKNESS: Mechanical concerns.
• Consider in patients with soft plaques in whom VLST may be
more frequent...
• What about complex lesions? I need studies.
Bioresorbable vascular scaffolding (BVS)
8-June-2011
CONCLUSIONS
• Fully bioabsorbable stents (BVS) are already here !
• Absorption and vessel wall integration are real
phenomena.
• We do not have to worry about acute recoil.
• Neo-intimal hyperplasia inhibited by everolimus.
• Vessel shrinkage (late recoil) solutioned with BVS 1.1.
• No early, late or very late ST observed in ABSORB
A&B (n=131) or the interim data of ABSORB-EXTEND.
• Concerns about acute gain (immediate result) in
some subsets. Thus, lesions not included in ABSORB
may be considered “off-label” (studies with complex
lesions needed).