SHA24/084004

SHA 24 February 2013

“Neurologist”

“Patient”

Nothing ASA & Physio CEA Modify RF

CAS Lytic Stenting

POBA BMS DESs DEB Bioabsorbable

Endarterectomy

1954

1977

Volume

Complications

Carotid stenting

1995 2011

Source: William A. Gray MD, Presented at Oxford University, England

7

Trial

30-Day Outcome (Death/Stroke)

EVA-3S (30 days)

CEA: 3.9%

CAS: 9.6%

p=0.01

ICSS (120 days)

CEA: 4.7%

CAS: 8.5%

p=0.001

CREST (Symptomatic Only)

CEA: 5.4%

CAS: 6.7%

p=0.30

Source: William A. Gray MD, Presented at Oxford University, England

8

Operator Experience

Trial

EVA-3S

Poor

ICSS

Poor

CREST

Adequate for era

(12 lifetime CAS or 35 supra-aortics with 5 CAS)

(50 stents anywhere, 10 lifetime CAS)

Source: William A. Gray MD, Presented at Oxford University, England

9

Trial

MI Ascertainment and Rates

EVA-3S

Not a primary endpoint.

Ascertainment not described.

CAS: 0.4% CEA: 0.8%

SPACE

Not a primary or secondary endpoint.

No routine ascertainment.

No MI’s reported.

ICSS

Not a primary endpoint.

Not routine ascertainment.

CAS: 0.4% CEA: 0.5%

CREST

Part of the primary endpoint.

Routine surveillance.

CAS: 1.1% CEA: 2.3%

Source: William A. Gray MD, Presented at Oxford University, England

10

EPD Use

Trial

EVA-3S

Not mandated until after the first 80 patients treated; ~20% of all CAS strokes

SPACE

27%

CREST

>95%

Source: William A. Gray MD, Presented at Oxford University, England

11

Trial

EPD Use

MI Ascertainment

Operator Experience

EVA-3S

+

0

0

SPACE

½+

0

++

+

0

0

++

++

++

ICSS

CREST

Source: William A. Gray MD, Presented at Oxford University, England

12

AHA Standards Symptomatic carotid stenosis: <6% CEA stroke and death rate ď&#x201A;Ą

Asymptomatic carotid stenosis: <3% CEA stroke and death rate

ď&#x201A;Ą

Per Protocol

Accunet® EPS Used N = 1,073

EPS Not Used N = 24

Difference [95% CI]1

All Death, Stroke, and MI2

5.3%

20.8%

-15.5% [-31.8%, 0.8%]

Death2

0.4%

8.3%

-8.0%

ANM

All Stroke2

3.8%

8.3%

-4.5%

ANM

Major Stroke

0.7%

4.2%

-3.4%

ANM

Minor Stroke

3.1%

4.2%

-1.1%

ANM

1.9%

8.3%

-6.5%

ANM

MI2

Note: Only includes each subject’s first occurrence of the event.

1 By normal approximation.

2 Hierarchical event in first row, all other are non-hierarchical events.

3 ANM: Assumptions Not Met Source: http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM247780.pdf

14

Why Embolic Protection?

MCA (M1) embolic occlusion

Proximal vs Distal Proximal : Flow Reversal 1. Gore 2. Invatec/Medtronic Distal: Filter or occlusive balloon 1.Abbott 2.Cordis

Proximal devices •Occlusion balloons in the external & common carotid artery resulting in cessation of flow in the internal carotid artery.

•Proximal balloon occlusion linked to a venous return site, retrograde blood flow in the internal carotid artery occurs.

•Following stent insertion, the proximal internal carotid artery is suctioned to remove debris prior to deflating the occlusion balloon Disadvantages: •They are larger than distal devices >> bigger sheaths •Cerebral ischemia may occur during flow reversal.

•Injury to the common & external carotid arteries may occur with balloon inflation.

ECA Balloon Reversal of blood flow in ICA with aspiration of debris

CCA Balloon

Distal Devices •Triple coaxial catheter : distal occlusion balloon with proximal aspiration of blood & debris following inflation.

•Other devices: deploy distal filters instead of balloons.

Disadvantages : • They must cross the stenosis • Tight lesions may require predilatation before device placement • They may induce vasospasm that can severely narrow the outflow & cause stroke if prolonged • Difficulty with removal of the device itself