1) The document discusses the history and development of interventional cardiology and drug-eluting stents. It provides details on the indications for use of different stent types as well as outcomes data comparing on-label and off-label use. 2) Bioresorbable vascular scaffolds (BRS) are described and compared to first generation drug-eluting stents. Limitations of BRS for treating STEMI patients are discussed. 3) Studies evaluating outcomes of overlapping BRS versus overlapping drug-eluting stents in stable angina patients and assessing strut coverage of overlapping devices at 28 and 90 days in pigs are summarized.

2. History of Interventional Cardiology
Brian Kaebnick
Bill D Gogas
Spencer B King III
1
Textbook: Interventional Cardiology, 2nd Edition 2016
On-label indications: symptomatic ischemic heart disease by de novo lesions ≤ 30 mm long in native coronaryarteries
of reference vessel diameter (RVD) of ≥ 2.5 to ≤ 3.5 mm (Cypher), lesions ≤ 28 mm long in arteries of RVD ≥ 2.5 to ≤ 3.75
mm (Taxus), and lesions ≤ 35 mm long in arteries of RVD ≥ 2.25 to ≤ 4.2 mm, including those with diabetes mellitus (RES)

3. 929 patients underwent PCI with DESs & were divided in 2 groups: on-label (n =
449) vs. off-label (n = 480) use. Off-label use: MI (<48 hours), small vessels (<2.5
mm), long lesions (>30mm), CTOs, bif. lesions, ostial lesions (<5mm from orifice),
LM & MV disease, SVG lesions.
Korean J Intern Med. 2016 Jul;31(4):678-84
MACE: 17.5% vs. 9.4%, (p < 0.001)MACE: 8.2% vs. 3.7%, (p = 0.005)

4. Modulus of Elasticity (GPa) Tensile strength (MPa) Elongation at break (%)
Poly-L-lactic acid 3.1-3.7 60-70 6
Poly-D,L-Lactide 3.1-3.7 45-55 6
Poly (glycolide) 6.5-7.0 90-110 2
Cobalt Chromium 210-235 1449 40
Stainless Steel 316L 193 668 40+
Nitilol 45 700-1100 20
Mg alloy 40-45 220-330 20
Modulus of elasticity:
Material’s resistance to applied force until it is elastically deformed (transient deformation)
Tensile strength:
Measures the force required to the point where the material breaks (permanent deformation)
Circulation. 2011; 123:779-797

5. 1st gen DES: Cypher 2nd gen DES: Xience V 1st gen BRS: Absorb BVS
Strut Thickness (μm) 152.6 81.3 157
Strut Width (link)
(μm) 60 81.3 140
Strut Width (hoop) 130μm 81.3μm 2.5, 3.00-mm: 190.5 μm
3.5-mm: 215.9 μm
Hiroyoshi Kawamoto, Richard J. Jabbour, Akihito Tanaka, Azeem Latib, Antonio Colombo
J Am Coll Cardiol Intv. 2016;9(3):299-300

6. Neth Heart J (2015) 23:161–165
Lesion level selection for BRS deployment
Yes No
Lesion: De novo Bifurcations: w/ SB RVD>2-mm
RVD: >2.5-mm & <3.8-mm Left Main Disease
Lesion length: 28-mm CTO
Overlap: 1 BRS scaffold In-stent Restenosis
Clinical status: Stable/Unstable/ Silent Ischemia Grafts: SVG
Tortuosity: Significant
Clinical status: STEMI or NSTEMI
RVD: < 2.5-mm
Calcification: Excessive
Patient level selection for BRS deployment
Yes No
Life expectancy> 5 years Age>80yo
Renal failure: Advanced
Dialysis
Cardiogenic shock
May be
DM, LVEF<40%, CVD, PAD, COPD, BMI>40

8. BRS are not recommended for lesions with >0.5-mm discrepancy between the prox. and distal MB RVD
Provisional Single-Stent Strategy is the Default Strategy
Prox
RVD
Distal
RVD
1
2 3
4

9. Provisional Single-Stenting Strategy - Sustained SB compromise
J Am Coll Cardiol Intv 2016;9:989–1000
JACC Cardiovasc Interv. 2011 Oct;4(10):1149-50
Snuggle kissing

10. Provisional Single-Stenting Strategy - Sustained SB compromise
J Am Coll Cardiol Intv 2016;9:989–1000
JACC Cardiovasc Interv. 2011 Oct;4(10):1149-50
Snuggle kissing

11. Provisional Single-Stenting Strategy - Sustained SB compromise
J Am Coll Cardiol Intv 2016;9:989–1000
JACC Cardiovasc Interv. 2011 Oct;4(10):1149-50

13. Limitations of BRS in the setting of STEMI:
1. Vessel Sizing: The large thrombotic burden and the associated adrenergic
stimulation obscure the accurate estimation of the reference vessel diameter
inducing scaffold: artery size mismatch.
2. Optimal Lesion Preparation: The aggressive lesion preparation in a large
thrombotic substrate increases the risk of distal embolization and no reflow.
3. Prolonged Inflation Time: The stepwise inflation of 2-Atm every 5-sec up to the
nominal pressure and the 30-sec sustained balloon inflation may increase the risk
of ischemia in vulnerable myocardial territories
49 eligible patients presented with STEMI were evaluated with quantitative coronary
angiography and optical coherence tomography during AbsorbTM BVS Implantation
Eur Heart J. 2014 Mar;35(12):777-86

14. 49 eligible patients presented with STEMI were evaluated with quantitative coronary angiography and
optical coherence tomography during AbsorbTM BVS Implantation
Prox/mid LAD lesions Thrombectomy 2 Absorb BVS
The procedural success was 97.9%. Pre-procedure TIMI-flow was 0
in 50.0% of the patients; after the BVS implantation,a TIMI- flow III
was achieved in 91.7% of patients
Excellent acute performance
Excellent clinical outcomes @ 30 days

15. The primary endpoint was a device-oriented endpoint (DOCE), including cardiac death, target vesselMI and TLR @ 1-year
290 STEMI patients treatedby Absorb BVS, comparedwith either 290 STEMI patients treatedwith EES or 290 STEMI
patients treated with BMS from the EXAMINATION trial, by applying propensity score matching
J Am Coll CardiolIntv 2015;8:189–97

17. 51 overlapping Absorb BVS and Xience V (XV) devices were implanted in the main coronary arteries of 17 nonatherosclerotic pigs.
Implanted coronary arteries were evaluated by OCT at 28 days and 90 days.
1. At 28 days 80.1% vs. 99.4%, (p=0.0001) of Absorb BVS vs. XV struts were covered
2. Uncovered struts were almost exclusively related to the presence of “stacked” Absorb struts, that is, with a direct overlay configuration.
3. At 90 days, overlapping Absorb and overlapping XV struts demonstrated 99% strut coverage by OCT and histology.
Absorb BVS 28 days Xience V
Absorb BVS 90 days Xience V

18. 70 stable angina patients treated with overlapping bioresorbable scaffolds and 70 patients treated with overlapping new generation
everolimus stents. The primary outcome was the 1-year MACE rate.
MACE free survival @ 1Y
Minimize Overlap
Rev Esp Cardiol. 2016;69(12):1135–1143
1. DES Distal: 2.75 × 28 mm DES Xience Prime
2. BVS Proximal: 3.0 ×18 mm Absorb BVS
Int J Cardiol. 2015;186:74-6
DES
BRS

19. BVS for CTO recanalization demonstrates excellent feasibility and safety as well as midterm efficacy.
Appropriate lesion preparation is key to aiding adequate expansion of these scaffolds in this setting.

20. Neth Heart J (2015) 23:161–165
Lesion level selection for BRS deployment
Yes No
Lesion: De novo Bifurcations: w/ SB RVD>2-mm - yes, w/ restrictions
RVD: >2.5-mm & <3.8-mm Left Main Disease: (-)
Lesion length: 28-mm
Clinical status: STEMI, encouraging results, further evidence is
needed
Overlap: 1 BRS scaffold In-stent Restenosis: (-)
Clinical status: Stable/Unstable/ Silent Ischemia Grafts: SVG (-)
Tortuosity: Significant (-)
CTO: - encouraging results, further evidence is needed
RVD: < 2.5-mm (-)
Calcification: Excessive (-)
Patient level selection for BRS deployment
Yes No
Life expectancy> 5 years Age>80yo
Renal failure: Advanced
Dialysis
Cardiogenic shock
May be
DM, LVEF<40%, CVD, PAD, COPD, BMI>40