1. Renu Virmani, MD. CVPath Institute, Inc. Gaithersburg, MD, USA.
Does Neoatherosclerosis Contribute to Very Late Stent Thrombosis of BMS and DES
Renu Virmani, MD.
CVPath Institute, Inc.
Gaithersburg, MD, USA.

2. Disclosure Speaker's name: Renu Virmani, MD
 I have the following potential conflicts of interest to report:
Consultant: 480 Biomedical, Abbott Vascular, Medtronic, and W.L. Gore.
Employment in industry: No
Honorarium: 480 Biomedical, Abbott Vascular, Boston Scientific, Cordis J&J, Lutonix, Medtronic, Merck, Terumo Corporation, and W.L. Gore.
Institutional grant/research support: 480 Biomedical, Abbott Vascular, Atrium, BioSensors International, Biotronik, Boston Scientific, Cordis J&J, GSK, Kona, Medtronic, MicroPort Medical, CeloNova, OrbusNeich Medical, ReCore, SINO Medical Technology, Terumo Corporation, and W.L. Gore.
Owner of a healthcare company: No
Stockholder of a healthcare company: No

3. Problems Encountered with Drug-Eluting Stents
1st-generation DES
2nd-generation DES
Thick struts
Uneven polymer distribution with poor integrity, and thick coating of durable polymers
High drug dose
Thinner struts
More biocompatible polymer (Durable)
Reduced drug dose
Uncovered struts
Hypersensitivity
Malapposition from fibrin deposition
Stent fracture
Neoatherosclerosis
Uncovered struts
Hypersensitivity
Malapposition from fibrin deposition
Stent fracture
Neoatherosclerosis
Clinical Late Catch-up
Late Stent Thrombosis / Restenosis Th Th Th Th
Malapposition from excessive fibrin deposition
Hypersensitivity
reaction
Late catch-up
Uncovered struts
Neoatherosclerosis

4. Representative Images of Neoatherosclerosis
Foamy macrophage clusters
Fibroatheroma
NC formation close to the luminal surface
Early NC with microcalcification  NC    
Late Fibroatheroma
Late Fibroatheroma with hemorrhage
Late NC with hemorrhage and calcification NC NC Ca  
This slide shows representative images of neoatherosclerosis.
Neoatherosclerosis was defined as the presence of foamy macrophages within the neointima with or without necrotic core and/or calcification.
Thin-cap Fibroatheroma
In-stent plaque rupture Th Th NC 
Neoatherosclerosis was defined as the presence of foamy macrophages within the neointima with or without necrotic core and/or calcification.

5. Prevalence of Various Features of Neoatherosclerosis
BMS vs. 1st-gen DES
Foamy Macrophage Clusters
Fibroatheromas
Thin-cap fibroatheroma / Plaque rupture
Duration of Implant
(%)
(%)
(%)
(days)
p<0.001
p=0.145
p=0.169
p<0.001
Median: 721 days
15%
14%
10%
Median: 361 days 4% 3% 1%
n=7
n=3
BMS
(n=197)
DES
(n=209)
BMS
(n=197)
DES
(n=209)
BMS
(n=197)
DES
(n=209)
BMS
(n=197)
DES
(n=209)
Foamy Macrophages
Fibroatheroma
TCFA
Plaque Rupture
(SES, 13 months)
(SES, 17 months)
(BMS, 61 months)
(BMS, 61 months)
Nakazawa G, Otsuka F, et al. J Am Coll Cardiol 2011;57:

6. In-stent Plaque Rupture (Neoatherosclerosis)
43M, BMS (ML Zeta), 61 months
43M, BMS (Mini-Crown) 84 months
Thr
47M, BMS (GR II), 96 months Th Th *
61M
DES (SES) 37 months * * * *
Thr * * * *
In-stent plaque rupture secondary to neoatherosclerosis was another etiology of late stent thrombosis.
In these cases, thin-cap fibroatheroma with fibrous cap disruption were observed within the in-stent segment.
You can see the significant different duration of implant between the groups.
In-stent plaque rupture within BMS occurred beyond 5 years, whereas for DES, it was identified with duration of implant less than 2 years. *
59M, DES (SES), 23 months Th 
Nakazawa G, Otsuka F, et al. J Am Coll Cardiol 2011;57: Otsuka F, et al. Nat Rev Cardiol; 2012:

7. Erosion of the Neointima
With Restenosis
Without Severe Restenosis
45F, BMS (Crown stent) implanted in LCX for 4 months, died suddenly.
52M, DES (SES) implanted in LAD for 2 years, died suddenly.
This slide shows representative images of erosion of the neointima.
The left panel shows a case of erosion of the neointima with restenosis, from a 45-year-old woman with a BMS implanted in LCX 4 months antemortem, who died suddenly. You can see the adherent thrombus to the neointima.
Similar finding was observed in case without restenosis as shown in the right panel. This case is a 52-year-old man with SES implanted in LAD 2 years antemortem, who died suddenly. Again, the adherent thrombus to the neointima was observed.

8. Pathologic Etiologies and Time Distribution of LST / VLST
BMS vs. 1st-gen DES
Uncovered struts
(DES; n=40) vs. (BMS; n=0)
Uncovered strut is the primary pathologic substrate responsible for LST/VLST in 1st-gen DES.
SES (n=19/120)
DES (n=45/245)
Penetration of the necrotic core
PES (n=26/125)
Bifurcation stenting
(available in <6 years)
BMS (n=6/237)
Long / overlapping stents
Underexpansion
Isolated uncovered struts
Hypersensitivity reaction
Malapposition from excessive fibrin
Erosion
(DES; n=2) vs. (BMS; n=2)
BMS shows biphasic late thrombotic events; LST from erosion and VLST (≥5 years) from in-stent plaque rupture.
with severe in-stent restenosis
without severe in-stent restenosis
In-stent plaque rupture from neoatherosclerosis
(DES; n=3) vs. (BMS; n=4)
with severe in-stent restenosis
In-stent plaque rupture occurs earlier in DES than in BMS.
without severe in-stent restenosis 1 2 3 4 5 6 7 8 9 10
Duration of implant
(years)

9. Independent Risk Factors for Neoatherosclerosis (Multiple Logistic Generalized Estimating Equations Modeling)
Variables
Odds Ratio
95% CI
P value
Age (per year)
0.963
0.942 – 0.983
<0.001
Duration of implant (per month)
1.028
1.017 – 1.041
SES usage
6.534
PES usage
3.200
0.001
Underlying unstable lesion*
2.387
0.004
In order to determine independent risk factors for neoatherosclerosis, we performed multiple logistic regression analysis.
Younger age, longer duration of implant, SES usage, PES usage, and underlying unstable lesion were identified as independent determinant of neoatherosclerosis.
* “Underlying unstable lesion” includes ruptured plaque and thin-cap fibroatheroma.
Nakazawa G, Otsuka F, et al. J Am Coll Cardiol 2011;57:

10. Prevalence and Characteristics of Neoatherosclerosis:
CoCr-EES vs. SES/PES (duration of implant >30 days, ≤3 years)
Overall Prevalence of Neoatherosclerosis
Prevalence of Various Features of Neoatherosclerosis
(%)
(%)
p=0.91
p=0.19
p=0.15
p=0.32
35%
SES (n=72, median duration=270 days)
p=0.69
p=0.13
PES (n=78, median duration=211 days)
29%
21%
20%
CoCr-EES (n=41, median duration=180 days)
17%
19%
11%
10%
p=0.52
N/A 3% 2% 0% 0%
SES
(n=72)
PES
(n=78)
EES
(n=41)
SES
PES
EES
SES
PES
EES
SES
PES
EES
Foamy macrophage clusters
TCFA / in-stent plaque rupture
Fibroatheroma
All statistical analyses were corrected for duration of implant.
Otsuka F, et al. Circulation Jan 14;129(2):211-23

11. Neoatherosclerosis in the 2nd-generation DES
Foamy macrophage clusters
R-ZES 12M 
CD68
Foamy macrophage clusters  
CoCr-EES 24M  
Neoatherosclerosis is observed even in the 2nd-generation DES; both in CoCr-EES and Resolute-ZES.
CD68
Fibroatheroma
CoCr-EES 36M NC NC NC  
CD68
Images for CoCr-EES are published in: Otsuka F, et al. Circulation 2014;129:

12. Prevalence of Neoatherosclerosis:
Overall, with Stent Thrombosis, and with Restenosis
Neoatherosclerosis (overall)
Neoatherosclerosis with stent thrombosis
Neoatherosclerosis with in-stent restenosis
Prevalence (%)
65%
51%
52%
48%
38%
Neoatherosclerosis develops more frequently and at earlier time point in 1st- and 2nd-generation DES as compared with BMS.
Involvement of neoatherosclerosis in stent thrombosis and restenosis increases with time.
In BMS, neoatherosclerosis with restenosis or stent thrombosis was observed only after 3 years, whereas in 1st-generation DES, those occurs at earlier time point.
2nd-generation DES are available for only earlier time point.
17%
13%
15.4% 6%
9.7%
4.8%
3.6%
6.5% 0%
4.3% 6% 0%
0.9% 0% NA 0% 0%
0.9% 0% 0% 0%
Duration of implant
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>3 y
(n=17)
>3 y
>3 y
(n=64)
(n=85)
(n=117)
(n=111)
(n=112)
(n=62)
(n=42)
(n=21)
BMS
1st-gen DES
2nd-gen DES

13. VLST Attributed to Neoatherosclerosis (In-Stent Plaque Rupture)
Stent thrombosis (overall)
Stent thrombosis from neoatherosclerosis (in-stent plaque rupture)
Prevalence (%)
100% of VLST
33% of VLST
5% of VLST
6.5%
4.3%
The involvement of neoatherosclerosis in VLST increased with time.
For BMS, neoatherosclerosis accounts for 100% of VLST (>3 years), whereas in 1st- generation DES, only 33% have VLST from neoatherosclerosis after 3 years (other causes include hypersensitivity, malapposition and uncovered struts).
0.9% 0% 0% 0% 0% 0% 0%
Duration of implant
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>3 y
(n=17)
>3 y
>3 y
(n=64)
(n=85)
(n=117)
(n=111)
(n=112)
(n=62)
(n=42)
(n=21)
BMS
1st-gen DES
2nd-gen DES
The involvement of neoatherosclerosis in VLST increased with time.
For BMS, neoatherosclerosis accounts for 100% of VLST (>3 years), whereas in 1st-generation DES, only 33% have VLST from neoatherosclerosis after 3 years.

14. In-Stent Restenosis with Underlying Neoatherosclerosis
Restenosis (overall)
Restenosis with underlying neoatherosclerosis
Prevalence (%)
67% of Reste-nosis
31% of Reste-
nosis
6% of Reste-
38% of Reste-
25% of Reste-nosis
15.4%
9.7% 6% 0%
4.8% 0%
3.6%
The involvement of neoatherosclerosis in restenosis increased with time.
In stents that have restenosis after 3 years, 1st-generation DES showed a higher percentage of neoatherosclerosis (67%) as compared with BMS (38%).
0.9%
Duration of implant
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>30 d, 1 y
>1 y,
3 y
>3 y
(n=17)
>3 y
>3 y
(n=64)
(n=85)
(n=117)
(n=111)
(n=112)
(n=62)
(n=42)
(n=21)
BMS
1st-gen DES
2nd-gen DES
The involvement of neoatherosclerosis in restenosis increased with time.
For restenosis after 3 years, 1st-generation DES showed a higher percentage of neoatherosclerosis (67%) as compared with BMS (38%).

15. Why neoatherosclerosis is accelerated in DES as compared to BMS?

16. Consequences of Low Shear Stress
In regions of disturbed flow and low shear stress, there is endothelial dysfunction with impaired NO-dependent atheroprotection
Inflammation
MCP-1
Thrombosis
VCAM
vWF
ICAM
Blood Flow & Pressure:
 Shear Stress
IL-1
PAI-1
Endothelium
DisturbedFlow
Smooth Muscle
VEGF
This cartoon illustration shows the effect of disturbed flow dynamics and low shear stress on endothelial dysfunction, resulting in the release of signals that are pro-thrombotic, pro-inflammatory, and promote disease progression.
Angiotensin II
PDGF
ET-1
Disease Progression
TXA2
Vasoconstriction
Adapted from I. Meredith, TCT 2009
 Atherosclerosis and thrombosis

17. Poorly Formed Cell Junctions
71-year-old woman who died of stroke
BMS Implanted in RCA 2 y antemortem
SES Implanted in LAD 16 m antemortem
Rabbit iliac arteries 14 d post implant
Pavement-shaped endothelial cells with endothelial cell-to-cell contact, a small area exhibits poorly formed cell junctions
Poorly formed endothelial cell junctions
Guagliumi G, et al. Circulation 2003;107:
Otsuka F, et al. Nat Rev Cardiol; 2012:

18. Incompetent Endothelium Following Stent Implantation
Regenerated endothelium following intravascular injury is incompetent, which is characterized by:
Poorly formed intercellular junctions
Reduced expression of antithrombotic molecules
Decreased nitric oxide production
Flow disturbances following stenting may change the endothelium phenotype from quiescent to inflammatory, and increase its thrombogenicity.
Dual immunofluorescence for PECAM-1 and thrombomodulin (TM) in stented segment of rabbit iliac arteries at 14 days. (Joner M, et al. JACC 2008)
PECAM-1
SES
PES
ZES
EES
BMS TM
Merged

19. Chronic total occlusion (CTO) Non-occlusive restenosis
Representative Images of In-Stent Restenosis with Underlying Neoatherosclerosis
Chronic total occlusion (CTO)
Non-occlusive restenosis
Representative Images of In-Stent Restenosis with Underlying Neoatherosclerosis
Non-occlusive restenosis and chronic total occlusion (CTO)

20. Summary
Neoatherosclerosis develops rapidly and more frequently in 1st- and 2nd-generation DES as compared to BMS.
The involvement of neoatherosclerosis in late stent failure increases with time in both BMS and 1st-generation DES.
For BMS, neoatherosclerosis accounts for 100% of VLST (>3 years), whereas in 1st-generation DES, only 33% have VLST from neoatherosclerosis after 3 years (other causes include hypersensitivity, malapposition and uncovered struts).
In all stents that have restenosis after 3 years, 1st-generation DES show a higher % of neoatherosclerosis (67%) as compared to BMS (38%).
In-stent plaque rupture can occur from lesions with non-significant luminal narrowing, especially in DES.
Neoatherosclerosis as a cause of thrombosis for 2nd-generation DES remains unknown but is observed as part of restenosis.
Neoatherosclerosis develops rapidly and more frequently in 1st- and 2nd-generation DES as compared with BMS.
The involvement of neoatherosclerosis in late stent failure increases with time in both BMS and 1st-generation DES.
For BMS, neoatherosclerosis accounts for 100% of VLST (>3 years), whereas in 1st- generation DES, only 33% have VLST from neoatherosclerosis after 3 years (other causes include hypersensitivity, malapposition and uncovered struts).
In all stents that have restenosis after 3 years, 1st-generation DES show a higher % of neoatherosclerosis (67%) as compared to BMS (38%).
In-stent plaque rupture can occur from lesions with non-significant luminal narrowing, especially in DES.
Neoatherosclerosis as a cause of thrombosis for 2nd-generation DES remains unknown but is observed as part of restenosis.

21. Acknowledgments Funding CVPath Institute CVPath Institute Inc.
Fumiyuki Otsuka, MD, PhD
Kenichi Sakakura, MD
Kazuyuki Yahagi, MD
Robert Kutys, MS
Oscar Sanchez, MD
Ed Acampado, DVM
Youhui Liang, MD
Abebe Atiso, HT
Jinky Beyer
Hedwig Avallone, HT
Lila Adams, HT
Hengying Ouyang, MD
Erica Pacheco, MS
Frank D Kolodgie, PhD
Michael Joner, MD
Renu Virmani, MD
Washington DC

22. VLST from in-stent plaque rupture (n=10) Duration of implant (years)
Time Distribution of VLST From In-Stent Plaque Rupture With or Without Restenosis
Rupture with restenosis
VLST from in-stent plaque rupture (n=10)
SES
PES
BMS
With restenosis
(n=4)
Rupture without restenosis
Without restenosis
(n=6) 1 2 3 4 5 6 7 8 9
Thr
Duration of implant (years)
This slide shows time distribution of VLST from in-stent plaque rupture with or without restenosis.
VLST from in-stent rupture occurs earlier in 1st-generation DES as compared with BMS.
Of the 10 lesions with in-stent plaque rupture, only 4 (3 in BMS and 1 in 1st-gen DES) had in-stent restenosis.
In-stent plaque rupture can occur from lesions with non-significant narrowing, especially in DES.
VLST from in-stent rupture occurs earlier in 1st-generation DES as compared with BMS.
Of the 10 lesions with in-stent plaque rupture, only 4 (3 in BMS and 1 in 1st-gen DES) had in-stent restenosis.
In-stent plaque rupture can occur from lesions with non-significant luminal narrowing, especially in DES.

23. TCFA and Rupture cases in DES1 59 M
DES
(SES) 23
months 2 61 36 3 78 F 46 4 43 72 5
(PES) 60
Case
Age, Sex
Stent type
Duration of implant, months
Representative images
Thin-cap fibroatheroma 1 40 F
DES
(SES) 17
months 2 67 M 13 3 49 36 4 60
(PES)
Nakazawa G, Otsuka F, et al. J Am Coll Cardiol 2011;57:

24. CVPath Registry BMS 1st-generation DES 2nd-generation DES
614 stented native coronary lesions (384 patients) with duration of implant >30 days
Bypass graft lesions were excluded.
BMS
1st-generation DES
2nd-generation DES
266 lesions
(195 patients)
285 lesions (192 patients);
143 SES and 142 PES
63 lesions (46 patients);
7 E-ZES, 3 R-ZES, and 53 EES
All available material with duration of implant >30 days (mean, 913±989 days) from our autopsy stent registry to include a total of 384 cases (mean age=61±13 years, 287 male) with 614 stented lesions in native coronary arteries (BMS=266, 1st-generation DES=285 [143 SES and 142 PES], and 2nd-generation DES=63 [7 E-ZES, 3 R-ZES, and 53 EES]) were examined by light microscopically following dehydration and embedding in methyl methacrylate and cut at 3 mm intervals.
>30 days, 1 year
>1 year, 3 years
>3 years
217 lesions
BMS = 64
1st-gen DES = 111
2nd-gen DES = 42
218 lesions
BMS = 85
1st-gen DES = 112
2nd-gen DES = 21
179 lesions
BMS = 117
1st-gen DES = 62
2nd-gen DES = N/A