Ghanem et al., J Am Coll Cardiol 2010;55:1427–32.

Background 

• Aortic valve replacement is recommended in patients with symptomatic severe valvular stenosis.

• Transfemoral aortic valve implantation (TAVI) offers a therapeutic option for high-risk patients with multiple comorbid conditions.

Vahanian et al., European Journal of Cardiothoracic Surgery 34 (2008)

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 pre-interventional risk stratification, peri-interventional anticoagulation management...

Grube et al., JACC (2007), Webb et al., Circulation (2008), Zajarias et al., JACC (2009)

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 pre-interventional risk stratification, peri-interventional anticoagulation management...

Grube et al., JACC (2007), Webb et al., Circulation (2008), Zajarias et al., JACC (2009)

Aim of the study:

Prospective investigation of peri-interventional

cerebral embolism (3rd generation

Corevalve™-Prosthesis) with DW-MRI and its

relationship with clinical (NIHSS) and

serological (NSE) parameters of brain injury.

Study designInclusion criteria:

– severe, symptomatic aortic stenosis with or without regurgitation and high peri-operative risk or

– explicit patient‘s request and– aortic valve annulus diameter >20 and <27 mm, and– diameter of the ascending aorta <45 mm at the sinotub.

junction.

Exclusion criteria:– Age < 18 years– Pregnancy / lactation period– Contraindications to MRI (PM, ICD, Claustrophobia …)

Study designEvaluation

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

ProtocolE1

E2

E3

• Death (n=2)

• New onset of claustrophobia (n=1)

• Hemodynamic instability (n=1)

• PM-Therapy (n=4)

TAVI

•DW-MRI•NIHSS (n=30)•NSE

•DW-MRI (n=22)•NIHSS•NSE

•DW-MRI (n=22)•NIHSS•NSE

Clinical data

Age, years ± SD 79.3 ± 4.8

Male, n (%) 8 (36.4)

Body-mass-index, kg/m² ± SD 26 ± 6.2

Log. EuroScore, % ± SD 19.4 ± 13.5

STS - score mortality, % ± SD 6.2 ± 4.2

STS - score permanent stroke, % ± SD 2.8 ± 1.3

NYHA ± SD 3 ± 0.5

Comorbidities

Hypertension, n (%) 21 (95)

Diabetes, n (%) 5 (23)

Dyslipidemia, n (%) 20 (91)

Prior stroke, n (%) // Prior TIA, n (%) 6 (27) // 3 (14)

Peripheral vascular disease, n (%) 15 (68)

Aortic atheroma ≥ 4 mm, n (%) 11 (50)

CHADS2 – score ± SD 3.1 ± 1.1

Baseline characteristics

Serology

0

1

2

3

4

Lac

tate

[m

mo

l/l]

0

10

20

30

40

80

85

90

NS

E [

µg

/l]

E1 E2 E3 E1 E2 E3

MRI

Lesion localisation and size

Vascular territories

DW-MRI lesion volume range

[cm³]

Anterior cerebral artery

0.1 – 59.2

Middle cerebral artery

0.1 – 4.5

Posterior cerebral artery

0.1 – 8.6

Vertebro-basilary

arteries

0.1 – 1.6

NIHSS

0

2

4

16

18

20N

IH-S

tro

ke S

core

n=30

n=1

n=1

n=1

n=27

E1 E2 E3

DW-MRI lesions

absent present

Clinical data n=6 n=16 P

Age, years ± SD 79.7 ± 5 79.2 ± 4.9 0.84

Male, n (%) 1 (17) 7 (44) 0.26

Body-mass-index, kg/m² ± SD 26.1 ± 8 25.9 ± 5.7 0.95

Log. EuroScore, % ± SD 19.0 ± 9.2 19.6 ± 15 0.62

STS - score mortality, % ± SD 6.5 ± 2.6 6.1 ± 4.7 0.81

STS - score permanent stroke, % ± SD

2.7 ± 0.8 2.9 ± 1.5 0.64

NYHA ± SD 3 ± 0.6 3 ± 0.5 1.0

Comorbidities

Hypertension, n (%) 5 (83) 16 (100) 0.27

Diabetes, n (%) 1 (17) 4 (25) 1.0

Dyslipidemia, n (%) 5 (83) 15 (94) 0.48

Prior stroke, n (%) // Prior TIA, n (%)

1 (17) // 0 (0) 5 (31) // 3 (19) 0.63

Peripheral vascular disease, n(%)

2 (33) 13 (81) 0.054

Cerebral vascular disease, n (%) 1 (17) 7 (44) 0.35

Aortic atheroma ≥ 4 mm, n (%) 2 (33) 9 (56) 0.63

Atrial fibrillation, n (%) // flutter, n (%)

2 (33) // 1 (17) 7 (44) // 1 (6) 1.0

CHADS2 – score ± SD 2.8 ± 0.8 3.2 ± 1.2 0.5

• DW-MRI, but not NSE, detects cerebral embolic lesions.

• Silent cerebral embolism is freuquent following TAVI (73%)

• The incidence of apparent cerebral embolism is low (3.6%).

Results

• Pilot study, small sample size, single site data collection, no multivariate analysis for risk factors.

• The incidence of silent and apparent embolism may differ with the Edwards-SAPIEN prosthesis.

• DW-MRI following transapical AVI could help elucidating the influence of retrograde passage of the aortic arch and valve as potential embolic sources.

Limitations

Conclusions

• The incidence of clinically silent peri-interventional cerebral embolic lesions is high.

• However, in this cohort of 30 patients, the incidence of persistent neurological impairment was low.

• Further studies are needed to evaluate independent risk factors for peri-interventional cerebral embolism.