Dr Donald Baim

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Distal protection devices

• Dr Donald Baim
• Director, Center for Innovative Minimally
  Invasive Therapy
• Brigham Womens Hospital
• Boston, MA

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Distal protection devices
Origins

• Original PCI studies did not show any significant
  embolic debris, resulting in a mindset against
  the idea of distal embolization.
• But results in saphenous vein grafts where
  perfect anatomic results still resulted in slowed
  antegrade flow.

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Distal protection devices
Competing explanations

• 1) Platelets releasing serotonin, provoking
  microvascular spasm and causing slow flow.
• 2) Platelet aggregates causing blockage.
• 3) Distal embolization of plaque debris.
• (now the leading explanation)

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Distal protection devices
Devices

• Balloon PercuSurge GuardWire
• (A low-pressure elastic balloon put distal to the
  lesion and then inflated to seal the vessel.
  After PCI, debris is aspirated.)
• Filter Cordis Angioguard, MedNova Filter,
  Microvena TrapÔ VFS, etc
• (Filter is deployed distally. Liberated debris is
  captured, the filter is then collapsed and
  withdrawn from the body.)

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Distal protection devices
Debris capture
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Distal protection devices
Clinical use

• Many devices are already CE marked for Europe.
• PercuSurge GuardWire registries
• SAFE
• (Saphenous Vein Graft Angioplasty Free of Emboli)
  
• CAFE
• (Carotid Angioplasty Free of Emboli)

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Distal protection devices
Clinical trials

• Only one randomized trial has been completed.
• SAFER
• (Saphenous Vein Graft Angioplasty Free of Emboli
  Randomized)
• 750 patients randomized to PCI treatment either
  with or without the PercuSurge GuardWire.

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SAFER Primary endpoints
p-value 0.001
Baim DS, et.al., Transcatheter Cardiovascular
Therapeutics 2000
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Distal protection devices
Canadian registry

• Set the stage for the randomized trials.
• Showed that using the capture devices, embolic
  debris was found with every SVG, and that the
  rate of MACE in the registry was lower than the
  historical norm.
• Showed the material can be recovered and that
  recovery seemed to lower the number of clinical
  events.

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CAFE registry
122 patients receiving carotid stenting and
protected by PercuSurge GuardWire
Mehran R, et.al., American Heart Association
Scientific Sessions 2000
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The embolic material

• What is being captured?
• Shattered version of the plaques that one sees in
  cross section of the arteries before treatment.
• The plaques that liberate the most debris seem to
  have the biggest pools of lipids, the unstable
  plaques.

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Native coronaries

• Perception is that there is less embolization
  than in SVG.
• Analyses from Europe suggests that distal
  embolization may prevent people with acute
  infarction from restablishing normal myocardial
  perfusion post PCI.

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Restenosis risk

• The two devices have advantages and
  disadvantages.
• Either has the potential to injure the distal
  vessel.
• Balloon is a complete barrier, but interrupts
  flow for a few minutes.
• Filter leaves flow, but could allow the smaller
  particles through.

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When will you use it?

• Because this no-reflow event is so unpredictable
  and because it has such devastating consequences,
  people are not going to want to play Russian
  roulette, and use of a distal protection device
  will become the standard of care for all
  saphenous vein graft interventions.
• Dr Donald Baim
• Director, Center for Innovative Minimally
  Invasive Therapy
• Brigham Womens Hospital
• Boston, MA

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GP IIb/IIA interaction

• GPIIb/IIIa receptor inhibitors were used in 60
  of patients in both arms of the SAFER trial,
  mostly started before intervention, chosen
  non-randomly by the operators.
• SAFER found that use GP IIb/IIIa made no
  appreciable difference in the significant
  reduction of events with distal protection.

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Learning curve

• Successful use of device requires close
  coordination of the stent operator and the distal
  capture device operator.
• The average operator did 5-7 cases with the
  device before beginning the randomized trial.

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Cost

• No-reflow SVG patients have a very high
  in-hospital mortality when no-reflow. Probably is
  cost-effective there.
• Cost-efficacy data is being collected.

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FDA approval

• First device of its type.
• The trial was stopped early because of apparent
  efficacy and safety.
• Company has asked for expedited review.
• Perhaps sometime in January 2001.