Coronary Stenting

1
Coronary Stenting

• Anjan Gupta, MD
• Milwaukee Heart
• Institute
• Milwaukee,Wisconsin

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Stents

• Coronary stents have
• revolutionized the field
• of coronary angioplasty
• due to their ability to
• prevent abrupt closure of
• the artery after
• angioplasty and also by
• reducing restenosis

3
Incidence of major clinical end-points -
Benestent Trial
NEJM 1994331489 - 495
4
Survival for Major Cardiac events (Death, MI,
CABG and Repeat angioplasty) - STRESS trial
NEJM 1994 331 496 - 501
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Changes in luminal dimension over time after
coronary intervention
Reference artery Post procedure
Late loss
Follow-up
Acute gain
Net gain
Baseline
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Predictors of restenosis in calcified and complex
lesions
Lesions
Restenosis (18) No Restenosis (62) P-value
Preprocedure Proximal Reference diameter
2.99 ? 0.41 3.22 ? 0.56
0.13 Lesion Length, mm
13.5 ? 9.1 8.3 ? 5.5
0.004 Lesion Type C
39 11
0.007 Procedural Elective stenting
77
76 0.57 Stents per
lesion 2.1 ? 1
1.6 ? 1
0.13 Rotablation
22 3
0.02 Postprocedure Angiographic stent
MLD, mm 2.86 ? 0.4 3.26 ? 0.56
0.006 IVUS stent MLD, mm
2.54 ? 0.34 2.8 ? 0.53
0.05 IVUS stent CSA, mm2
6.37 ? 1.71 7.42 ? 2.27
0.085
Moussa et al, Circulation 199796128
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Probability of restenosis after coronary
intervention
Hypothetical 3.5 mm artery
2.45mm (30)
3.15mm (10)
3.5 mm (0)
3.85mm (-10)
Kuntz et al, Circulation 1992861827 - 1835
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Minimal lumen diameter 6 months after the
intervention as a function of reference vessel
size
plt0.05 plt0.01 plt0.05
Savage et al, JACC 199831307 - 11
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Small stent size and intimal hyperplasia
contribute to restenosis
No Restenosis Restenosis p - value
Quantitative Angiography Reference (mm)
3.38 ? 0.51 3.14 ?
0.43 0.076 MLD (mm)
2.53 ? 0.52 0.90 ?
0.57 lt0.0001 Diameter stenosis ()
24.8 ? 11.9 73 ? 17
lt0.0001 Intravascular ultrasound Reference
lumen CSA(mm2) 11.7 ? 4.2
9.7 ? 2.3 lt0.05 Minimal lumen CSA(mm2)
5.9 ? 2.48 1.79 ? 0.89
lt0.0001 Minimal stent CSA (mm2) 8.97
? 3.01 7.3 ? 3.29
lt0.05 Stent volume (mm3) 147
? 43 120 ? 41
0.016 Lumen volume (mm3) 118 ?
42 62 ? 28
lt0.0001 Intimal hyperplasia (mm3) 29
? 18 58 ? 36 lt0.001
Dussaillant et al, JACC 199526720
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Subacute stent thrombosis in the era of IVUS
guided coronary stenting without anticoagulation
Moussa et al, JACC 1997296 - 12
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Randomized comparison of antiplatelet and
anticoagulant therapy after coronary stenting
Cardiac events
Non-cardiac events
Schomig et al, NEJM 19963341084-9
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Cumulative event rate for Death, MI or Urgent
Revascularization - EPISTENT Trial
10.8
6.9
Patients ()
5.3
Days from randomization
Lancet 199835287-92
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Stenting in small vessels
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In-stent Restenosis in small vessels treated with
rotational atherectomy
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Restenosis rates after balloon angioplasty and
coronary stentingin small arteries
Savage et al, JACC 199831307 - 11
16
Event-free survival after angioplasty and
stenting in small coronary arteries
Savage et al, JACC199831307 - 311
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Restenosis rate in patients with follow-up
angiography
P0.0001 P0.0012
P NS
Akiyama et al, JACC 1998321610-1618
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Restenosis in Intravascular ultrasound guided
stent group
Akiyama et al, JACC 1998321610-1618
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Quantitative angiographic measurements of lesions
with follow-up angiography
Large vessels Small vessels P-value
Baseline measurements Reference diameter
3.45 0.39 2.64 0.28
0.0001 MLD (mm) 0.95
0.53 0.79 0.38
0.0001 Diameter stenosis () 71
14.9 70 14.5
NS Postproc. Measurements MLD (mm)
3.37 0.54 2.85 0.44
0.0001 Diameter stenosis ()
1.61 12.2 -2.63 14.9
0.0001 Follow-up Measurements MLD(mm)
2.33 0.99 1.73 0.87
0.0001 Diameter stenosis ()
28.2 27.9 37.5 29.8
0.0001 Acute gain
2.42 0.69 2.06 0.58
0.0001 Late loss
1.05 0.91 1.11 0.85 NS Loss
index 0.45 0.45
0.56 0.47 0.0006
Akiyama et al, JACC 1998321610-1618
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Restenosis rate with different stent designs
Slotted tubular stents
Coil stents
P 0.0012
Akiyama et al, JACC 1998321610-1618
21
Survival curves for the combined end-point of
Death, MI, CABG or TLR during follow-up after
stenting
Akiyama et al, JACC 1998321610-1618
22
Univariate predictors of restenosis in patients
with IVUS guided stenting
No Restenosis Restenosis P-value
Clinical factors Age (years)
57.1 9.2 58.6 9.9
0.09 Procedural factors Balloon/Vessel ratio
1.18 0.17 1.21 0.20
0.25 Final pressure (atm)
16 3.2 16.3 3.1
0.26 Stents/Lesion 1.5
0.9 1.8 1.2
0.003 Quant. Angio. Meas. Reference diam (mm)
3.14 0.52 2.89 0.45
0.001 Lesion length (mm) 10.6
6.7 12.4 7.7 0.008 Final
MLD (mm) 3.25 0.56
2.96 0.48 0.001 Final stenosis
-2.9 13.1 -0.3 14.1
0.04 Acute gain
2.36 0.66 2.17 0.61
0.001
Akiyama et al, JACC 1998321610-1618
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Univariate predictors of restenosis in patients
with IVUS guided stenting
No Restenosis Restenosis p-value
Quantitative IVUS measurements Average vessel
CSA(mm2) 13.8 4.2 11.9 3.4
0.001 In-stent minimum LD(mm)
3.2 0.6 3.0 0.5
0.001 In-stent minimum CSA (mm2) 8.1 2.5
6.9 2.1 0.001 Optimal result
in IVUS 82
64 0.006
Akiyama et al, JACC 1998321610-1618
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Multivariate predictors of freedom from
restenosis in patients with IVUS guided stenting
Standardized p Coefficient value
Total Cohort Odds Ratio CI
Angiographic 2.03
1.22 - 3.38 0.2
0.006 reference diameter Final in-stent CSA
1.19 1.07 - 1.33
0.24 0.0001 Lesion length
1.04 1.01 - 1.07
-0.14 0.01
Akiyama et al, JACC 1998321610-1618
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SUMMARY

• Patients who undergo stenting in small coronary
  vessels have similar short-term outcome as
  patients who have stenting in large vessels
• Small vessel stenting is associated with a higher
  restenosis rate compared to stenting in larger
  vessels

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SUMMARY

• The achievement of a larger final CSA inside the
  stent is a major variable associated with a lower
  restenosis rate in both small and large vessels
• Slotted tubular stents perform better in larger
  vessels compared to coil stents
• Both stents perform suboptimally in preventing
  restenosis in small vessels