Stroke During TAVI: An Unmet Clinical Need? - Paragon Conventions

Stroke During TAVI: An
Unmet Clinical Need?
Stephen J.D. Brecker

Disclosures
I have the following financial
relationships to disclose:
Proctor: Medtronic
(Moderate)
*Type of relation: Consultancy, employment, honoraria, other
compensation
*Level of remuneration: high (over $50,000 yearly), moderate (10-50,000),
modest (under 10,000)

Stroke prevention in TAVI: An unmet
clinical need?
• The impact of stroke on TAVI outcomes
• The mechanisms of stroke during TAVI
• Stroke prevention – what can we do?

Results of TAVI are improving
• Source
• Corevalve 18F
• UK registry
• Partner trial

Stroke is still a major source of co-
morbidity
• 2.9%–6.7% of patients undergoing
transfemoral TAVI (with both the Edwards
SAPIEN or CoreValve device) and 1.8%–5% of
patients undergoing transapical
TAVI (Edwards SAPIEN).

Stroke post TAVI – The registry data

The Source Registry

Source 30 day outcomes
No major difference between femoral and apical access

New Perspectives on Stroke
During TAVI
Ghanem et al., J Am Coll Cardiol 2010;55:1427–32.

Background
• TAVI-related stroke is an important complication (1-
10%). The risk of silent cerebral embolism is not
elucidated yet.
• Diffusion-weighted MRI allows detection and
localization of acute - apparent and silent - ischemic
cerebral lesions.
• DW-MRI studies are of potential interest for preinterventional
risk stratification, peri-interventional
anticoagulation management...
Grube et al., JACC (2007), Webb et al., Circulation (2008), Zajarias et al., JACC (2009)

Study design
Evaluation
Clinical and neurological assessment (NIHSS)
Lab - Tests (incl. Lactate, NSE)
MRI
TAVI
Clinical and neurological assessment (NIHSS)
Lab - Tests (incl. Lactate, NSE)
MRI
Clinical and neurological assessment (NIHSS)
Lab - Tests (incl. Lactate, NSE)
MRI
E1
E2
E3

E1
DW-MRI•
NIHSS (n=30) •
NSE•
TAVI
E2
DW-MRI (n=22) •
NIHSS•
NSE•
E3
DW-MRI (n=22) •
NIHSS•
NSE•
Protocol
Death (n=2)
New onset of claustrophobia (n=1)
Hemodynamic instability (n=1)
PM-Therapy (n=4)
•
•
•
•

DW - MRI

Lesion localisation and size
Vascular
territories
Anterior
cerebral artery
Middle
cerebral artery
Posterior
cerebral artery
Vertebrobasilary
arteries
DW-MRI lesion
volume range [cm³]
0.1 – 59.2
0.1 – 4.5
0.1 – 8.6
0.1 – 1.6

NIH-Stroke Score
20
18
16
4
2
0
NIH Stroke Scale
n=30
n=1
n=1
n=1
n=27
E1 E2 E3

Results
• DW-MRI, but not NSE, detects cerebral embolic
lesions.
• Silent cerebral embolism is frequent following
TAVI (73%)
• The incidence of apparent cerebral embolism is
low (3.6%).

What about Transfemoral vs
Transapical?

Study Design

DW-MRI Results Post TAVI

Larger Number of MRI Lesions in
TA group

Neurological and Cognitive Test
Results

Conclusions
• TAVI was associated with a high rate ( 68% ) of
new silent cerebral ischaemic lesions as
evaluated by DW-MRI, with no differences
between the TF ( 66%) and the TA (71%)
approaches
• The occurrence of new silent cerebral
ischaemic lesions was not associated with an
impairment of neurological or cognitive
functions

Significance of MRI lesions?
• No long term clinical significance or just
NIHSS/Cognitive function testing not sensitive
enough to pick them up?

What are the mechanisms of
• Crossing the aortic valve
• Arch atheroma
• Balloon valvuloplasty
• Pigtail catheter thrombosis
• Valve deployment
Stroke during TAVI
• Post dilatation balloon/valvuloplasty

Mechanisms of Stroke during TAVI
– Crossing the aortic valve

Mechanisms of Stroke during TAVI –
Crossing the aortic valve
• Silent and apparent cerebral embolism after
retrograde catheterisation of the aortic valve
in valvular stenosis : a prospective,randomised
study Omran H Lancet 2003 12;361(9365):1241-6
• 22% (22/101) patients had focal diffusion
imaging abnormalities on MRI
• 3% clinically apparent neurological defects
• All 51 patients with AS who did not have the
valve crossed had no abnormalities on MRI

Mechanisms of Stroke during TAVI –
Arch Atheroma

Aortic Atheroma And AS

Mechanisms of Stroke during TAVI –
Balloon valvuloplasty

Mechanisms of Stroke during TAVI –
Balloon valvuloplasty
• Stroke rates in literature range from 1-5%
Cribier A,Percutaneous transluminal valvuloplasty of acquired aortic stenosis in elderly patients:
an alternative to valve replacement? Lancet. 1986;1:63-67.
Safian RD, Balloon aortic valvuloplasty in 170 consecutive patients. N Engl J Med. 1988;319:125-
130.
Otto CM, Mickel MC, Kennedy JW, et al. Three year outcome after balloon aortic valvuloplasty:
insights into prognosis of valvular aortic stenosis. Circulation. 1994;89:642-650.
Eltchaninoff H, Cribier A, Tron C, et al. Balloon aortic valvuloplasty in elderly patients at high risk
for surgery or inoperable. Immediate and mid-term results. Eur Heart J. 1995;16:1079-1084.
Pedersen WR, Klaassen PJ, Boisjolie CR, et al. Feasibility of transcatheter intervention for severe
aortic stenosis in patients > 90 years of age: aortic valvuloplasty revisited. Cathet Cardiovasc
Interv. 2007;70:149-154.

Mechanisms of Stroke during TAVI –
Catheter Thrombosis
• Long periods of valve repositioning in difficult
cases
• Pigtail catheter thrombosis
• Trade off in anticoagulation between stroke
risk and vascular complications from closure
device failure
• Ideal ACT for procedure?

Mechanisms of Stroke during TAVI –
Valve Deployment

What can we do stop the shower?

The Future of Stroke Prevention in TAVI?
Umbrella/deflector devices
3 currently available devices:
The Claret Dual Filter device•
The Embrella device•
The Aortic Embolic Protection Device (AEPD )
•

Brachiocephalic trunk
Cerebral Filter Protection
Claret Device
Left
Common
carotid

Claret Dual Filter

Embolic Material

Embolic Material

Embrella Embolic Deflector
• Porous membrane
designed to deflect
embolic debris
• Nitinol frame and shaft
• Polyurethane Porous
membrane
• Heparin coating
• 3 radiopaque markers
• Suture, Monofilament
Nylon

Concept Embrella
Separate access site from main •
procedure, Radial or brachial
artery
Fits through a 6F sheath•
Minimal orientation•
Ease of use, no new techniques•
Low profile•
One size fits all•
Deflect debris•

Embrella Case Example

Embrella Case Example

Embrella Case Example

Embrella Case Example – No
difficulty crossing device

Embrella Clinical Experience

11 fold decrease in MRI lesion
volume

Average number of Lesions/Subject

55% decrease in TCD Hits

Aortic Embolic Protection Device
( AEPD)
SMT Research and Development, Ltd.,
Herzliya, Israel

What about post TAVI?

Post TAVI Antiplatelet Therapy
• No randomised trials as yet.
• Initial experiences with TAVI and no DAP –
thrombus noted on the valves.
• Elderly patients on DAP have a significant
incidence of bleeding
• Needs evaluation

Thank you for your attention