Statins Reduce Vascular Injury in a Preclinical and Clinical Model of Arteriosclerosis

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Statins Reduce Vascular Injury in a Preclinical
and Clinical Model of Arteriosclerosis
G. M. Biasi MD A. Froio MD M. Busnelli, PhD
G. Deleo, MD R. Giovannoni, PhD M.G. Cerrito,
PhD V. Camesasca, MD A. Liloia, MD C. Benatti,
MD R. Palermo, MD B.E. Leone, MD M. Lavitrano,
PhD University of Milano-Bicocca, Milan
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Statins Vascular Diseases

• Statins reduce the risk of stroke and myocardial
  infarction.
• A meta-analysis showed that the relative risk
  reduction was 60 for myocardial infarction and
  17 for stroke.
• Law, BMJ 2003 326 1423.

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Statins Protective effect

• 2 issues
• How can statins reduce vascular damage?
• Has the protective effect any clinical impact in
  the indication to treatment for patients with
  carotid plaques?

Animal Model
Clinical Setting
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Aim of the Preclinical Study Animal Model

• To investigate the effect of statins
• in the pathogenesis of vascular damage
• (molecular mechanism)
• in the prevention of vascular damage
• Carotid balloon injury model in healthy and
  hypercholesterolemic pigs.

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Animal model Methods 1

• 21 pigs (general anesthesia)
• left carotid artery
• vascular injury balloon oversizing (4F Fogarty
  catheter)
• Intimal Hyperplasia and Stenosis

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Animal model Methods 2

• Blood analysis blood cell count,
  cholesterolemia, cytokines.
• Carotid samples (after 60 days) morphometric and
  immuno-histochemical analysis
• Animal care and experimental procedures met
  local, national, and European Union Guidelines

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Animal model Methods 3
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Results Cholesterolemia
Result 1. High-cholesterol diet significantly
increases total cholesterolemia. Total
cholesterolemia is not reduced by statin treatment
Result 2. HDL-cholesterol fraction is
significantly increased by statin treatment
Result 3. LDL-cholesterol fraction is
significantly decreased by statin treatment
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Results Vascular Damage
STANDARD DIET
HIGH-CHOL. DIET
Result 4. Atorvastatin significantly reduces
vascular damage and degree of stenosis (plt0.05)
HIGH-CHOL DIET STATIN
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Results PBMCs analysis
Result 5. High-cholesterol diet significantly
increased the number of total WBCs and monocytes
(vs standard diet). Result 6. Treatment with
atorvastatin reduced WBCs and monocytes to
standard levels.
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Results Stenosis Inflammation
a
a
a
Result 7. Increase of stenosis correlated with
increase in the number of neutrophils, total WBCs
and platelets plt0.05 (independently by diet and
treatment received)
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Results Cytokines
Result 8. Atorvastatin treatment significantly
reduces pro-inflammatory cytokines TNF-alpha
(plt0.05)
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Results Molecular Mechanism Statins Protective
Gene expression
Inducible Nitric Oxide Synthase (iNOS) and Heme
Oxygenase-1 (HO-1) are essential for vascular
homeostasis
HIGH-CHOL DIET
NORMAL DIET
HIGH-CHOL DIET STATIN
HIGH-CHOL DIET
NORMAL DIET
HIGH-CHOL DIET STATIN
iNOS
HO-1
Result 9. iNOS and HO-1 are expressed following
vascular damage to trigger the protective effect.
Result 10. Atorvastatin treatment further
increases both iNOS and HO-1 expression.
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Results Molecular Mechanism Statins Protective
Gene expression
iNOS and HO-1 protective genes
Result 11. Reducing smooth muscle cell
proliferation (evaluated by Ki67
immuno-assay) Result 12. Increasing smooth muscle
cell apoptosis (evaluated by Caspase-3
immuno-assay)
Result 13. Reduction of vascular stenosis
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Conclusions 1

• Statins reduce vascular damage in a preclinical
  model of arteriosclerotic disease.
• Statin protective effect is mediated by iNOS and
  HO-1 with a decrease in the inflammatory response.

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Aim of the Clinical Study

• To investigate the effect of statins in the
  stabilization of carotid plaques
• in atherosclerotic patients with carotid stenoses
• evaluated by ultrasound.

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Clinical Study Methods

• Carotid ultrasound before statin treatment
• GSM evaluation
• Blood sampling
• Statin therapy
• Carotid ultrasound and GSM 90 days later

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Results 1

• Less-vulnerable plaque
• Lower embolic risk

Result 14. Mean GSM before therapy 42
Mean GSM after therapy 73
Result 15. Statin treatment increased carotid
plaque echogenicity, promoting plaque
stabilization and decreasing plaque vulnerability

• Vulnerable plaque
• High embolic risk

Carotid plaque echogenicity
73
Mean GSM value
42
Without therapy
After 90 days
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Results 2
Patient 23
GSM47
Enrollment
GSM69
90 days later
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Conclusions 2

• Statins stabilize carotid atherosclerotic
  plaques, reducing the vulnerability and the risk
  to embolize to the brain.

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Perspective

• Endarterectomy and endovascular treatment should
  be compared to statin treatment in a randomized
  trial in the prevention of stroke in patients
  with carotid atherosclerosis.
• -- TACIT trial --