1. University Hospital La Paz
03:15 pm – 03:30 pm
Lecture: Bioresorbable vascular scaffolding (BVS) in clinical practice: what can we expect after CE Mark?
Good afternoon. I would like to thank the organization committee for having invited me to participate in this congress. It is a great honour for me to be here in this meeting.
The issue we are going to address in the following minuts is what can we expect after CE Mark of BVS in clinical practice.
Raul Moreno
University Hospital La Paz
Madrid, Spain

2. START randomized study (n=452) Long-term follow-up
8-June-2011
Bioresorbable vascular scaffolding (BVS)
START randomized study (n=452)
Long-term follow-up
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.
The benefit of CS over balloon alone angioplasty was shown in several randomized trials 2 decades ago. And this benefit was confined to the first 6 months, because the benefit of CS is a reduction in the rate of restenosis and the need for TVR. Beyong the 1st year, however, it is not clear whether there is any advantage or disadvantage or having a permanent vascular scaffolding in the coronary wall. What seems to be clear it is that mechanical support is …
JACC 1999;34;

3. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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!
Late stent thrombosis after BMS implantation is very infrequent, However, the risk of stent thrombosis even with BMS never completely dissapears. This is ilustrated by these 2 cases that occurred in our center, with ST demonstrated by angiography in patients 8 years and 12 years after a BMS implantation.
J Invasive Cardiol 2008;20:E

4. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
The problem of VLST is more evident with DES
But now DES are used in a very high proportion of patients undergoing PCI. And late and very late ST, although also infrequent, are more frequent with these devices in comparison with BMS. Because of that, the interest of having a coronary stent that dissapear after having fulfilled its scaffolding function has grown during the last years, and there are several companies that are trying to develop a temporal vascular scaffolding with efficacy and safety.
Am J Med 2006;119:
J Am Coll Cardiol 2008;52:

5. Is there a need for bioabsorbable stents?
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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.
Bioa

6. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
Previous bioabsorbable stents
REVA
AG 1.81; LL mm
LL: NIH & loss of stent area Mg
AG 1.42; LL 1.08 mm
PROGRESS-AMS
Late loss (4 months):
42% vessel shrinkage
45% hyperplasia
Too quick absortion
Late loss
(mm)
Net gain = 1
BMS
DREAMS
AG 1.44; LL 0.68 mm
BIOSOLVE-1
This is also represented in this figure…
This figure represents wich may be the ideal mechanical properties of a new coronary stent. BMS have … BA has … DES have ..., and these devices are in the ideal area of the figure.
The problem of Mg stent from Biotronic is that it has a too high late loss. BA
PES
SES
EES
Acute gain
(mm)
Lancet 2007;369:1869 PCR 2011
TCT 2009 & TCT 2010

7. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
Polylactic acid
*Polymer: a large molecule (macromolecule) composed of repeating structural units.
L-LA
D-LA
Lactic Acid
(C3H6O3)
Meso L,D-LA
CO2
&
H2O
Krebs Cycle
Racemic D,L-LA
Poly-lactic acid
Poly-L-LA (PLLA).
Poly-D,L-LA (PDLLA).
etc.
~LA~LA~LA~LA~LA~LA~
Polylactic acid is also a polymer. As every polymers, polylactic acid is a large molecule composed of repeating… The structural unit of polylactic acid is lactic acid, that may adopt different forms such as LLA, DLA, etc, and therefore there may be different types of polylactid acid.
Anyway, poly-lactic acid, in the organism, is again transformed into lactic acid, that through the Krebs cycle is degradated into C02 and water, thus allowing a complete degradation and absorption of the polymer.
Polilactid acyd is a polymer that may be fully bioabsorbed and has been used in medicine for very different purposes. This polymer is made from lactic acid, and is a very good candidate for developing BVS.
J Exp Biol 2005;208:4561

8. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
REVA
Late loss
(mm) Mg
Net gain = 1
BMS
Tamai
(PLLA)
AG 1.57; LL .75 mm
LL: neo-intimal hyperplasia
DREAMS BA
PES
SES
EES
Acute gain
(mm)
Circulation 2000;102: TCT 2009 & TCT 2010

9. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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

10. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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.
0.30
0.50
1.98
NIH area (mm2)
-16.6
-7.2
-29.4
Ʌ Lumen area (%)
-11.2
-0.3
-2.0
Ʌ Stent area (%)
0.44
0.10
0.87
Late loss (mm)
BVS
EES
BMS
*EES and BMS provided by SPIRIT-I
6 mo. IVUS: reasons for late loss
Shrinkage (“late recoil”)
… that does not continue
from 6 mo. to 2 yr (!!)
Eurointervention 2005;1:58-65 Lancet 2008;371:
NCT

11. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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:
BVS 1.1
Cypher Select
Profile
1.40
1.23
Strut thickness (µm)
158 ( polymer)
164 ( polymer)

12. 8-June-2011
Bioresorbable vascular scaffolding (BVS)
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 NCT PCR 2011

13. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
REVA Mg
Late loss
(mm)
Net gain = 1
BMS
Tamai
(PLLA)
DREAMS
BVS-1
AG 1.24; LL .44 mm
Lancet 2008;371:899 BA
BVS-2
AG 1.26; LL .19 mm
TCT 2010
PES
SES
EES
Acute gain
(mm)

14. Preliminary data No episodes of stent thrombosis
8-June-2011
Bioresorbable vascular scaffolding (BVS)
ONGOING & FUTURE TRIALS:
■ ABSORB Extend: ~ 1,000 patients, 100 centers. Single arm.
No angio. follow-up (clinical end-points).
■ ABSORB Randomized study: ~ 500 patients. RCT vs Xience.
Angio follow-up.
Preliminary data
months
No episodes of stent thrombosis

15. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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.

16. Bioresorbable vascular scaffolding (BVS)
8-June-2011
Bioresorbable vascular scaffolding (BVS)
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).