Transcatheter aortic valve implantation for high-risk patients with severe aortic stenosis: A systematic review.

Abstract

The present systematic review objectively assessed the safety and clinical effectiveness of transcatheter aortic valve implantation for patients at high surgical risk with severe aortic stenosis.
Electronic searches were performed in 6 databases from January 2000 to March 2009. The end points included feasibility, safety, efficacy, and durability. Clinical effectiveness was synthesized through a narrative review with full tabulation of results of all included studies.
The current evidence on transcatheter aortic valve implantation for aortic stenosis is limited to short-term observational studies. The overall procedural success rates ranged from 74% to 100%. The incidence of major adverse events included 30-day mortality (0%-25%), major ventricular tachyarrhythmia (0%-4%), myocardial infarction (0%-15%), cardiac tamponade (2%-10%), stroke (0%-10%), conversion to surgery (0%-8%), moderate to major paravalvular leak (4%-35%), vascular complication (8%-17%), valve-in-valve procedure (2%-12%), and aortic dissection/perforation (0%-4%). The overall 30-day major adverse cardiovascular and cerebral events ranged from 3% to 35%. The mean aortic valve area ranged from 0.5 to 0.8 cm(2) before and 1.3 to 2.0 cm(2) after transcatheter aortic valve implantation. The mean pressure gradient ranged from 34 to 58 mm Hg before and 3 to 12 mm Hg after transcatheter aortic valve implantation. There was no significant deterioration in echocardiography measurements during the assessment period. Death rate at 6 months postprocedure ranged from 18% to 48%. No studies had adequate follow-up to reliably evaluate long-term outcomes.
The procedure has a potential for serious complications. Although short-term efficacy based on echocardiography measurements is good, there is little evidence on long-term outcomes. The use of transcatheter aortic valve implantation should be considered only within the boundaries of clinical trials.

Full text

Page 1

Transcatheter aortic valve implantation for high-risk patients with
severe aortic stenosis: A systematic review
Tristan D. Yan, BSc(Med), MBBS, PhD,a,bChristopher Cao, BSc(Med), MBBS,a
Julie Martens-Nielsen, MD,aRatnasari Padang, BSc(Med), MBBS,cMartin Ng, MBBS, PhD,c
Michael P. Vallely, MBBS, PhD, FRACS,a,band Paul G. Bannon, MBBS, PhD, FRACSa,b
Objectives: The present systematic review objectively assessed the safety and clinical effectiveness of trans-
catheter aortic valve implantation for patients at high surgical risk with severe aortic stenosis.
Methods: Electronic searches were performed in 6 databases from January 2000 to March 2009. The end points
included feasibility, safety, efficacy, and durability. Clinical effectiveness was synthesized through a narrative
review with full tabulation of results of all included studies.
Results: The current evidence on transcatheter aortic valve implantation for aortic stenosis is limited to short-
term observational studies. The overall procedural success rates ranged from 74% to 100%. The incidence of
major adverse events included 30-day mortality (0%–25%), major ventricular tachyarrhythmia (0%–4%),
myocardial infarction (0%–15%), cardiac tamponade (2%–10%), stroke (0%–10%), conversion to surgery
(0%–8%), moderate to major paravalvular leak (4%–35%), vascular complication (8%–17%), valve-in-valve
procedure (2%–12%), and aortic dissection/perforation (0%–4%). The overall 30-day major adverse cardio-
vascular and cerebral events ranged from 3% to 35%. The mean aortic valve area ranged from 0.5 to 0.8
cm2before and 1.3 to 2.0 cm2after transcatheter aortic valve implantation. The mean pressure gradient ranged
from 34 to 58 mm Hg before and 3 to 12 mm Hg after transcatheter aortic valve implantation. There was no
significant deterioration in echocardiography measurements during the assessment period. Death rate at 6 months
postprocedure ranged from 18% to 48%. No studies had adequate follow-up to reliably evaluate long-term
outcomes.
Conclusions: The procedure has a potential for serious complications. Although short-term efficacy based on
echocardiography measurements is good, there is little evidence on long-term outcomes. The use of transcatheter
aortic valve implantation should be considered only within the boundaries of clinical trials. (J Thorac Cardiovasc
Surg 2010;139:1519-28)
Aortic stenosis (AS) is the most common valvular heart dis-
ease in adults.1The disorder is becoming more frequent as
the age of the population increases, representing a growing
public health issue. Severe AS is universally fatal if left un-
treated, with three-quarters of patients dying within 3 years
of symptom onset.2No medical treatment improves survival
inchronicdisease,astheobstructiontooutflowtractrequires
mechanicalrelief.Mortalityratesaresignificantlyreducedin
symptomatic patients with AS by aortic valve replacement
(AVR).3Thus, AVR can be withheld in such patients only
when compelling contraindications exist. A recent prospec-
tivesurveyofpatientswithvalvularheartdiseasethroughout
Europe suggests that almost one-third of patients over the
age of 75 with severe AS do not undergo AVR, due to risks
arising from age and comorbidities.1These findings have
stimulated tremendous interest inreducing patient morbidity
and mortality and motivated the development of a less-inva-
sive transcatheter aortic valve (TAV) procedure.4-31
The analysis of The Society of Thoracic Surgeons
National Cardiac Database evidenced that, among 46,397
patients, mortality for surgical AVR ranges from 4.3% for
first isolated AVR to 25% for redo surgery or multiple valve
replacement plus coronary artery bypass grafting, with an
overall mortality rate of 6.4%.32Fish33states that surgical
results are excellent even in high-risk patients and that adop-
tion of a percutaneous approach must be justified and guar-
antee high performance. Many issues related to TAV
implantation remain to be clarified by clinical data. We per-
formed the present systematic review to objectively assess
the safety and clinical effectiveness of TAV implantation
in treatment of severe AS.
METHODS
Literature Search Strategy
Electronic searches were performed in 6 databases from January 2000 to
March 2009: MEDLINE, EMBASE, PubMed, Cochrane Central Register
FromDepartmentofCardiothoracic Surgery,aTheUniversity ofSydney, RoyalPrince
Alfred Hospital, Sydney, Australia; The Baird Institute for Applied Heart and Lung
Surgical,bSydney, Australia; and Department of Cardiology,cThe University of
Sydney, Royal Prince Alfred Hospital, Sydney, Australia.
Disclosures: None.
ReceivedforpublicationMay21,2009; revisionsreceivedJune28,2009;acceptedfor
publication Aug 9, 2009; available ahead of print Oct 21, 2009.
Address for reprints: Tristan D. Yan, BSc(Med), MBBS, PhD, The University of
Sydney, Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital,
Sydney 2050, Australia (E-mail: Tristan.Yan@unsw.edu.au).
0022-5223/$36.00
Copyright ? 2010 by The American Association for Thoracic Surgery
doi:10.1016/j.jtcvs.2009.08.037
The Journal of Thoracic and Cardiovascular SurgerycVolume 139, Number 61519
ACD
Yan et alAcquired Cardiovascular Disease

Page 2

Abbreviations and Acronyms
AS
¼ aortic stenosis
AVR
¼ aortic valve replacement
MACCE ¼ major adverse cardiovascular and
cerebral events
NYHA
¼ New York Heart Association
SD
¼ standard deviation
TAV
¼ transcatheter aortic valve
of Controlled Trials, Cochrane Database of Systematic Reviews, and Data-
baseofAbstractsofReviewofEffectiveness.Toachievethemaximumsen-
sitivity of the search strategy and identify all studies, we used appropriate
free text and thesaurus terms: ‘‘percutaneous’’ OR ‘‘transcutaneous’’ OR
‘‘transcatheter’’ OR ‘‘transarterial’’ OR ‘‘transapical’’ AND ‘‘aortic
valve’’ OR ‘‘aortic valve stenosis.’’ The reference lists of all retrieved arti-
cles were reviewed for further identification of potentially relevant studies.
Study Population
The study population was defined as patients of high surgical risk with
AS or those deemed not suitable for surgical AVR, whereas TAV implan-
tation was considered. The criteria for patient selection for TAV implanta-
tion varied among institutions, and the definitions for nonsurgical
candidates were not uniform.
Interventions
The balloon-expandable TAV consists of 3 pericardial leaflets, initially
equine (Cribier-Edwards; Edwards Life Sciences Inc, Irving, Calif) and
currently bovine (Edwards-Sapien; Edwards Life Sciences), mounted within
a tubular, slotted, stainless steel balloon-expandable stent. Initial devices
were 14 mm in length and 23 mm in expanded diameter, with a larger device
available subsequently (length 16 mm, expanded diameter 26 mm). Current
devices require either a 22F or 24F (transfemoral) or 26F (transapical) sheath
for delivery. Three different insertion techniqueshavebeenusedforEdwards
TAV: the original antegrade approach where the TAV is delivered via the
venous route; the retrograde approach by which it is delivered via an arterial
route;andthetransapicalrouterequiringaminithoracotomyfordeliveryofthe
device via the apex of the left ventricle. The self-expandable percutaneous
aortic valve (CoreValve; CoreValve, Irving, Calif) consists of 3 pericardial
tissue leaflets, initially bovine and currently porcine, mounted and sutured
in a self-expandable nitinol stent. The available valve diameters are 22 and
26mm.Earlydevicesrequired25Fsheaths.Second-generationdevicesincor-
porated porcine pericardial tissue that allowed decrease in profile to 21F
sheaths. The current device was further redesigned in the fixing of the valve
tissue onto the stent, decreasing the profile to 18F sheaths.
Outcome Measures
The findings from initial scoping searches were used in deciding which
outcomes to include in the present review. The primary end points included
feasibility and safety (procedural success rate, 30-day mortality, major
tachyarrhythmia, bradyarrythmia requiring permanent pacemaker insertion,
myocardial infarction, cardiac tamponade, cerebrovascular accident, con-
version to surgery, conversion to valvuloplasty, vascular complication,
moderate to severe paravalvular leak, valve-in-valve procedure, emergency
percutaneous coronary intervention, endocarditis, aortic dissection/perfora-
tion, blood transfusion>2 U, procedure duration, and length of hospital
stay). The secondary outcomes included efficacy and durability based on
echocardiographic findings and clinical outcomes at 1, 6, and 12 months
(mean aortic valve area before and after TAV implantation, peak and
mean pressure gradient before and after TAV implantation, left ventricular
ejection fraction beforeandafter TAV implantation, NewYork HeartAsso-
ciation [NYHA] functional class improvement versus baseline, numbers of
patients at risk at 6-month and 12-month reviews, and number of patients
deceased at 6-month follow-up).
Study Design and Selection Criteria
Ameta-analysiswasnotappropriatebecausenocomparisonsamongdif-
ferent devices or techniques of insertion have been reported, and the poten-
tial differences in prostheses might exist. Experimental or observational
studies were included in the present review. Case reports, abstracts, edito-
rials, and expert opinionswere excluded. Studies eligiblefor this systematic
review included high-risk patients with AS who received TAV implanta-
tion. When centers had published duplicate trials with accumulating num-
bers of patients or increased lengths of follow-up, only the most complete
reports were included for qualitative appraisal and data extraction.
Data Extraction and Critical Appraisal
The 2 investigators (T.D.Y. and R.P.) independently appraised each in-
cluded article, using a critical review checklist as recommended by the Na-
tional Health Service Center for Reviews and Dissemination case series
quality assessment criteria (University of York).34This consisted of repre-
sentativenessofstudysample,explicitnessofinclusioncriteria,similarityof
disease progression at the time of treatment, adequacy of follow-up, objec-
tivity of outcome measures, and appropriateness of subseries analysis. The
criteriaforassessingthequalityofmorbidityandmortalitydataincludedthe
following 4 points: whether there was an adequate explanation of how ad-
verse effects were identified; whether a standardized or validated measure-
ment instrument was used; how the adverse effect(s) was attributed to the
intervention; and whether the terms were clearly explained.
All data were extracted from the relevant articles’ texts, tables, and fig-
ures. Clinical effectiveness was synthesized through a narrative review with
full tabulationof resultsof allincludedstudies.Discrepanciesbetweenthe 2
reviewerswere resolvedbydiscussion andconsensuswitha third investiga-
tor (J.M.-N.). The final results were reviewed by all 3 senior investigators
(M.N., M.P.V., and P.G.B.).
RESULTS
Quantity of Studies
The titles and abstracts of 571 peer-reviewed publications
were identified through searching the 6 electronic databases.
Initial evaluation of these abstracts identified 57 potentially
relevant publications. Manual search of the reference lists
identified 4 additional publications of interest. When the in-
clusion and exclusion criteria were applied to these 61 pub-
lications, 28 articles4-31remained for assessment (Table 1).
Serial publications reporting accumulating numbers of pa-
tients or increased length of follow-up were identified. The
publication with most complete data set from each center
was retained. In total, 17 studies were included for appraisal
and data extraction (Table 2).6,9,11-13,16,18-23,25,27,29-31All
studies evaluated the feasibility and safety of TAV implan-
tation.Allexcept1study23assessedtheefficacyanddurabil-
ity of TAV using hemodynamic measurements by use of
echocardiography.
Quality of Studies
No randomized controlled trials or matched comparative
studies were identified. All 17 included articles were experi-
mental studies without control groups.6,9,11-13,16,18-23,25,27,29-31
1520The Journal of Thoracic and Cardiovascular SurgerycJune 2010
ACD
Acquired Cardiovascular Disease Yan et al

Page 3

TABLE 1. Summary of outcomes presented in relevant publications on transcatheter aortic valve implantation for high-risk patients with aortic stenosis
Treatment
center Reference Yearn
Success
rate
Post-TAV
mortality
Post-TAV
morbidity
Myocardial
infarction
Emergency
cardiac
surgery
Cerebrovascular
accident
Blood
transfusion
Length of
hospital
stay
Echocardiography
findings
NYHA
functional
class
Learning
curve Survival
Antegrade Edwards valve
Rouen, France4
5
6
7
2004
2004
2006
2007
6
8
C
C
C
C
CCC
C
C
C
36
36
C
C
C
C
CCCC
C
Retrograde Edwards valve
Vancouver, Canada8
9
2006
2007
2008
2008
2008
2008
18
50
40
12
12
24
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
CC
10
11
12
13
C
Paris, France
Athens, Greece
Quebec, Canada
Transapical Edwards valve
Vancouver, Canada
CC
C
C
C
C
C
C
CCC
14
15
16
17
18
19
20
21
2006
2007
2009
2007
2008
2008
2007
2008
7
7
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
26
30
50
26
59
40
C
C
C
C
C
C
C
C
Leipzig, Germany
C
C
C
C
C
CC
Frankfurt, Germany
Multicenter
Bicenter
CoreValve retrograde valve
Siegburg, Germany
Brighton, UK
Montreal, Canada
C
C
CCCC
22
23
24
25
26
27
2006
2008
2007
2007
2008
2008
25
12
10
13
13
33
CC
C
C
C
C
C
C
C
C
C
C
CCCCC
C
C
C
C
C
C
C
CC
C
C
C
C
C
C
C
C
C
C
CC
C
Rotterdam,
Netherlands
28
29
30
31
2008
2009
2007
2008 646
39
30
86
C
C
C
C
C
C
Catania, Italy
Multicenter
Multicenter
C
C
C
C
C
C
C
C
C
CC
C
C
C
C
C
C
C
C
TAV, Transcatheter aortic valve.
The Journal of Thoracic and Cardiovascular SurgerycVolume 139, Number 6
1521
ACD
Yan et al
Acquired Cardiovascular Disease

Page 4

TABLE 2. Summary of the 17 trials included in the present systematic review
Study
Referred
(n)
Attempted
(n)Study period
Age
(mean ± SD)
Logistic
EuroSCORE
(mean ± SD) Procedure
Procedural success,
n (%)
Antegrade Edwards valve
Rouen, France6
36332003–2005 80 ? 712 ? 2LA/sedation,
antegrade (26);
retrograde (7); rapid
ventricular pacing;
no CPB
27 (82)
Retrograde Edwards valve
Vancouver, Canada9
—502005–2006 82 ? 728 GA; retrograde;
rapid ventricular
pacing; no CPB
GA; retrograde, rapid
ventricular pacing
GA; retrograde (8);
transapical (4);
rapid ventricular
pacing; by
cardiologists and
cardiac surgeons
GA; retrograde (11);
apical (11); rapid
ventricular pacing;
by cardiologists
and cardiac surgeons
43 (86)
Paris, France11
3912 2006–200785 ? 6 31 ? 14 10 (83)
Athens, Greece12
— 122007–200881 ? 5 34 ? 15
12 (100)
Quebec, Canada13
2922 2007–2008 84 ? 7 26 ? 16 20 (91)
Transapical Edwards valve
Vancouver, Canada16
Leipzig, Germany18
Frankfurt, Germany19
Multicenter20
Bicenter21
Retrograde CoreValve valve
Siegburg, Germany22
—
83
—
—
163
26
50
26
59
40
2005–2007
2006–2007
2006–2008
2006
2006–2008
80 ? 9
82 ? 5
84 ? 7
81 ? 6
83 ? 8
37 ? 20
28 ? 12
37 ? 6
27 ? 14
36 ? 15
GA; minithoracotomy;
transapical; rapid
ventricular
pacing; by cardiac
surgeons
26 (100)
47 (94)
26 (100)
55 (93)
35 (88)
2525200580 ? 5 11*GA; retrograde; 24 and
21F sheaths;
fem-fem CPB
GA (3); LA/sedation
(9); retrograde; 18F
sheaths; rapid
ventricular pacing
GA; retrograde; CPB
Retrograde; rapid
ventricular pacing;
21 and 18F sheaths;
? CPB
LA/sedation or GA,
retrograde; 18F; rapid
ventricular pacing
GA or LA/sedation;
retrograde; 21F and
18F sheaths; ?
fem-fem CPB
LA/sedation or GA,
retrograde; 18F; rapid
ventricular pacing
21 (84)
Brighton, UK23
— 122007–200880* 22*12 (100)
Montreal, Canada25
Rotterdam, Netherlands27
29
—
11
33
2005–2006
2005–2007
82 ? 7
81 ? 7
36* 11 (100)
33 (100)
20 ? 12
Catania, Italy29
69 302007–2008 82 ? 525 ? 828 (93)
Multicenter30
— 862005–2007 82 ? 622 ? 13 64 (74)
Multicenter31
— 646 2007–200881 ? 723 ? 14628 (97)
CPB, Cardiopulmonary bypass; GA, general anesthetic; LA, local anesthetic; fem, femeral. *Median.
1522 The Journal of Thoracic and Cardiovascular SurgerycJune 2010
ACD
Acquired Cardiovascular Disease Yan et al

Page 5

All reports originated from specialized tertiary referral centers.
Fiveserieshad?50patients(range,50–646),9,18,20,30,31andthe
remaining 12 series had <50 patients (range, 11–40).6,11-
13,16,19,21-23,25,27,29The definitions of high-risk patients with
ASnotsuitableforsurgicalAVRvariedamongtheinstitutions.
For example, age>70,11,21>75,18-20,31>8025,30; NYHA func-
tionalclassIII/IV6,11,12;
cm2,12,19<0.7 cm2,6,11<0.6 cm2,21,25; logistic EuroSCORE
>20%,11,12,19,25,30additive EuroSCORE ?9,18,20Society of
Thoracic Surgeons score>15%,21and Parsonnet’s ?30.6
In 16 studies,6,9,11-13,16,18-23,25,27,29,30the number of pa-
tients evaluated was relatively small and the patients were
highly selected. The study sample in these 16 series was un-
likely to be fully representative of the study population and
was not large enough to provide definitive estimates of inci-
dence of all adverse events. It is acknowledged that the lack
of evidence of a rare adverse effect is not proof that such an
adverseeffectisnotassociatedwiththeprocedure.Onemul-
ticenter study assessed the procedural and 30-day outcomes
of 18F CoreValve in 646 patients.31Thirteen studies re-
ported explicit priori inclusion criteria,6,11,12,18-22,25,27,29-31
and 4 studies did not.9,13,16,23All studies reported proce-
dure-related or 30-day morbidity and mortality.6,9,11-13,
16,18-23,25,27,29-31Ten studies reported follow-up data at 6
months.6,9,11,13,16,18,20,22,25,29Eight studies reported fol-
low-up data at 12 months.6,9,16,18,20,22,25,29Two studies
had follow-up data on 2 and 3 patients beyond 2 years, re-
spectively.2,16No studies provided adequate long-term fol-
low-up data. All but 1 study23evaluated hemodynamic
measurements by echocardiography. Blinding was not re-
ported.Threestudiesperformedsubgroupanalysisassessing
procedural learning curve.9,18,30Morbidity, mortality, he-
modynamic measurements, and survival rates were objec-
tive outcome measures.
All studies clearly defined the techniques of TAV inter-
vention,andtherewasreasonableconsistencyinthedescrip-
tion of the techniques used for each approach. Clinical
adverse events were adjudicated by an independent clinical
committee in 3 studies,22,29,30not in 3 other studies,9,16,31
and not reported in the remaining 11 studies.6,11,12,16,18-21,
23,25,27The duration of follow-up was reported in 14
studies6,9,11-13,16,18-22,25,29,30and not in 3 studies.23,27,31
Six studies reported data according to periprocedural
majoradverse cardiovascular
(MACCE).6,21,22,29-31
In 11 studies, no standardized
measurement instrument was used for reporting adverse
events.9,11-13,16,18-20,23,25,27
The definitions of adverse
events were clearly explained in 8 studies6,9,16,21,22,29-31
and not in 9 studies.11-13,18-20,23,25,27
AVA
<1cm2,22,29-31<0.8
and cerebralevents
Assessment of Feasibility
The overall procedural success rates ranged from 74% to
100% (Table 2).6,9,11-13,16,18-23,25,27,29-31Cribier and associ-
ates6reported that 22 of the 26 antegrade implantations
(85%) of Edwards TAV were performed successfully with
4 technical failures. Two of these patients did not hemody-
namically tolerate the guide wire across the mitral valve.
In the other 2 patients, valve migration occurred immedi-
ately after implantation.
With the retrograde implantation of the Edwards prosthe-
sis, Webb and colleagues9achieved successful implantation
in 43 patients (86%). Reasons for failure included inability
to pass through the iliac artery (n ¼ 1) and cross the aortic
valve (n ¼ 3), a defective prototype delivery catheter (n ¼
1), and malpositioning (n ¼ 2). Descoutures and co-
workers11reported procedural success in 10 of 12 patients
(83%). Reasons for failure included inability to pass though
the iliac artery (n ¼ 1) and intraprocedural death from
hemopericardium, because of perforation of the left ventricle
by the wire (n ¼ 1). Rodes-Cabau and colleagues13reported
that procedural success was obtained in all but 2 patients
(91%). One transfemoral procedure was aborted due to
severely calcified femoral arteries, and the other patient died
during the procedure, presumably from ischemic heart
disease.
With the transapical approach, 2 single-institutional
studies reported 100% success rate.16,19Walther and as-
sociates18reported that 47 of 50 patients (94%) had
successful implantation, with 3 patients requiring early
conversion to open AVR. One multicenter study from
Leipzig, Vienna, Frankfurt, and Dallas20reported suc-
cessful transapical valve positioning in 55 patients
(93%) with the remaining 4 patients requiring conversion
to sternotomy, as the valves were incorrectly positioned.
In a bicenter study from Dallas and Cleveland,2135 of
the 40 TAVs (88%) were successfully seated. Two valves
embolized and required open AVR, and 1 case of severe
regurgitation later required AVR. Two additional patients
required cardiopulmonary support: 1 valve later embol-
ized and 1 migrated.
With the CoreValve prosthesis, 3 studies reported
100% success rate.23,25,27Grube and colleagues22reported
acute procedural success achieved in 21 of 25 patients
(84%). In 2 patients, significant paravalvular leakage
occurred, requiring open AVR. In 1 patient, the device
could not cross the heavily calcified native valve and the
patient died suddenly 12 hours after the balloon valvulo-
plasty. One additional patient died on the second postpro-
cedural day after successful device implantation as a result
of delayed pericardial tamponade secondary to wire perfo-
ration of the left ventricle. Tamburino and coworkers29
achieved procedural success in 28 of 30 patients (93%),
with1malpositioning of
a valve-in-valve procedure, and another patient sustained
a nonfatal pericardial tamponade. In the multicenter study
from Siegburg, Leipzig, and Montreal, acute device suc-
cess was achieved in 76 of 86 patients (88%), but the pro-
cedural success was 74%.30In 6 patients, misplacement of
the prosthesisrequiring
The Journal of Thoracic and Cardiovascular SurgerycVolume 139, Number 61523
ACD
Yan et al Acquired Cardiovascular Disease

Page 6

the valve led to emergency conversion to open AVR. In 2
patients, the device did not cross heavily calcified native
valves despite balloon predilatation. In 2 patients, subopti-
mal placement of the prosthesis resulted in aortic regurgi-
tation, requiring implantation of a second CoreValve
prosthesis. Finally, the largest collaborative study on 646
patients who had 18F CoreValve implantation demon-
strated a procedural success in 97% of the patients, and
the details of failure were not provided.31
Assessment of Safety
Table 3 demonstrates 30-day major cardiovascular and
cerebral adverse events following TAV across all stud-
ies.6,9,11-13,16,18-23,25,27,29-31The range of these adverse
events was as following: 30-day mortality (0%–25%); ma-
jor ventricular tachyarrhythmia (0%–4%); supraventricular
tachyarrhythmia (5%–31%); bradyarrhythmia requiring
permanent pace maker insertion (0%–36%); myocardial
infarction (0%–15%); cardiac tamponade (2%–10%);
cerebrovascular accident (0%–10%); conversion to sur-
gery (0%–8%); conversion to valvuloplasty (0%–4%);
vascular complication (8%–17%); moderate to major
paravalvular leak (4%–35%); valve-in-valve procedure
(2%–12%); emergency percutaneous coronary interven-
tion (0%–8%); endocarditis (0%); aortic dissection/rup-
ture (0%–4%); and blood transfusion >2 U (3%–24%).
The mean procedure duration varied from 2.5 to 2.9 hours.
The mean length of hospital stay ranged from 7 to 17 days.
The overall 30-day MACCE ranged from 3% to
35%.6,21,22,29-31
Assessment of Efficacy
The efficacy of TAV implantation was assessed based on
echocardiographicfindings(Table4).6,9,11-13,16,18-23,25,27,29-31
One study23did not report echocardiographic measure-
ments. The remaining 16 studies6,9,11-13,16,18-22,25,27,29-31
all demonstrated significant improvement in hemodynamic
performance (P < .05) when comparing preprocedural
with postprocedural (in-hospital) echocardiography mea-
surements. Left ventricular ejection fraction ranged from
41% to 56% before and 46% to 63% after TAV implan-
tation.
Assessment of Durability
Fifty percent to 100% of patients had improved NYHA
functional class at least by 1 grade at 1-month follow-
up.6,9,12,13,16,21,22,30As stated before, no studies had ade-
quate follow-up to reliably evaluate long-term outcomes.
Follow-up echocardiographic findings were available in 9
studies at 1 month,6,9,13,16,21,22,25,27,305 studies at 6
months,6,9,13,16,21and 3 studies at 12 months.6,9,16Accord-
ing to this information, there was no significant deterioration
in echocardiographic measurements during the assessment
period. Death rate at 6 months postprocedure ranged from
18%to48%.6,9,11,16,18,20,21,25OnestudybyCribierandcol-
leagues6reported that at 6 months, 16 of 27 patients (60%)
TABLE 3. Procedural and 30-d clinical outcomes following transcatheter aortic valve implantation
Studyn
Death at
30 d, n (%)
Major
tachyarrhythmia,
n (%)
Pacemaker
insertion,
n (%)
Myocardial
infarction,
n (%)
Cardiac
tamponade,
n (%)
Cerebrovascular
accident, n (%)
Conversion
to surgery,
n (%)
Antegrade Edwards valve
Rouen6
Retrograde Edwards valve
Vancouver9
Paris11
Athens12
Quebec13
Transapical Edwards valve
Vancouver16
Leipzig18
Frankfurt19
Multicenter20
Bicenter21
Retrograde CoreValve valve
Siegburg22
Brighton23
Montreal25
Rotterdam27
Catania29
Multicenter30
Multicenter31
336 (18)1 (3) 1 (3)0 2 (6)1 (3)0
50
12
12
22
6 (12)
3 (25)
0
2 (9)
2 (4)
—
—
1 (5)*
2 (4)
1 (8)
—
0
1 (2)
0
—
0
1 (2)
1 (8)
—
1 (5)
2 (4)
0
—
0
0
0
—
1 (5)
26
50
26
59
40
6 (23)
4 (8)
4 (15)
8 (14)
7 (18)
0
—
3 (12)
—
—
—
—
1 (4)
—
—
—
6 (15)
—
—
—
—
—
1 (4)
—
0
2 (3)
2 (5)
0
3 (6)
2 (8)
4 (7)
2 (5)
5 (19)*
18 (31)*
—
25
12
11
33
30
86
646
5 (20)
1 (8)
2 (18)
2 (6)
2 (7)
10 (12)
52 (8)
0
-
-
-
0
-
-
—
3 (25)
4 (36)
—
—
—
60 (9)
01 (4)
—
—
1 (3)
1 (3)
9 (10)
9 (1)
1 (4)
—
1 (9)
—
0
9 (10)
12 (2)
2 (8)
—
0
—
0
6 (7)
3 (1)
—
—
—
0
1 (1)
4 (1)
SD, Standard deviation. *Supraventricular arrhythmia. yMean.
1524The Journal of Thoracic and Cardiovascular SurgerycJune 2010
ACD
Acquired Cardiovascular DiseaseYan et al

Page 7

with successful implantation were dead. Further follow-up
of their patients was reported in a subsequent paper.7One
patient died at 10 months (reason unknown) and another at
30 months (renal failure). Ten patients were followed for
at least 1 year, 4 of them for 2 years, and 2 of them for 3
years.
Svensson and associates21reported on a Food and Drug
Administration–approved feasibility study incorporating
40 patients treated with a transapical inserted the Edwards
equine or bovine valve. This is the only published study re-
porting on quality-of-life data. Quality-of-life scores im-
proved from preoperatively (SF-12 Physical 28.7, standard
deviation 6.1; Mental 48.1, standard deviation 11.5) to post-
operatively at 6 months (SF-12 Physical35.2, standard devi-
ation 7.4; Mental 50.4, standard deviation 11.7). The
physical improvement was significant (P ¼ .002).
DISCUSSION
With the population aging, AS is becoming a more prev-
alentpublichealthissue.Medicaltherapyisunlikelytomod-
ify the course of the disease, especially once symptoms or
left ventricular dysfunction become manifest. Percutaneous
balloon aortic valvuloplasty has only a limited role in the
treatment of AS, as the results are not durable. Surgical
AVR remains the mainstay of definitive treatment.3Al-
though surgical therapy is effective, it entails the risks and
morbidity associated with cardiopulmonary bypass and
median sternotomy. When a frail and elderly patient with
significant comorbidities presents with severe AS, he or
she may be precluded from surgical AVR due to potentially
highoperativerisks.TAV implantation with its less invasive
nature is believed to offer a safer treatment solution for these
patients.35
In the current literature, no randomized controlled trials
have compared TAV implantation with conservative medi-
cal treatment, balloon valvuloplasty, or standard AVR.
The clinical experience with TAV is substantiated mainly
by short-term results. There is an ongoing randomized trial
(Placement of AoRTic TraNscathetER Valve trial in the
U.S.[PARTNERUS]; ClinicalTrials.gov
NCT00530894) using this valve comparing TAV implanta-
tion versus surgical AVR in patients at high surgical risk and
TAV implantation versus medical treatment or balloon aor-
tic valvuloplasty in patients at extreme surgical risk. The
present systematic review based on the available observa-
tional series demonstrated the following key points. First,
in view of the feasibility and safety results of TAV implan-
tation,theproceduresuccessraterangedfrom74%to100%
but there is a potential for serious complications. The 30-day
mortality (0%–25%), 30-day MACCE (range 3%–35%),
and 6-month mortality (18%–48%) were high, especially
in the initial reports.6,21,22,30Without randomized trials, it
is not clear whether the high interventional mortality risk as-
sociated with TAV insertion is lower than the risk associated
with conventional surgery. The procedural and short-term
outcomes appeared to be improving in more recent studies
identifier
Conversion to
valvuloplasty,
n (%)
Vascular
complications,
n (%)
Paravalvular
leak>2þ,
n (%)
Valve-in-valve
procedure,
n (%)
Aortic dissection/
perforation,
n (%)
Transfusion>2 U,
n (%)
Procedural
duration,
hours ± SD
Length
of stay,
days ± SD
—— 5 (15)—————
—
—
—
—
6 (12)
2 (17)
1 (8)
0
3 (6)
4 (33)
1 (8)
4 (18)
—
—
1 (8)
1 (5)
1 (2)
—
—
—
9 (18)
2 (17)
—
1 (5)
—5y
2.9 ? 1.2
—
—
17 ? 8
8 ? 2
7 ? 3
0
—
—
—
—
—
—
2 (8)
—
—
1 (4)
—
6 (23)
3 (5)
14 (35)
1 (4)
—
—
—
—
—
1 (2)
1 (4)
—
—
3 (12)
—
—
—
1 (3)
—
—
9 ? 5
—
—
—
—
2.5 ? 1.5
2.5 ? 1.5
—
1 (4)
—
—
—
0
2 (2)
—
—
1 (8)
—
—
5 (17)
—
12 (2)
2 (8)
—
—
—
2 (7)
—
—
—
—
—
4 (12)
1 (3)
2 (2)
17 (3)
0 6 (24)
—
2 (18)
—
—
—
—
——
3–5y
13.5y
—
—
—
—
—
—
—
0
0
4 (1)
1.8–2.3y
.5y
—
1.0 ? 0.3
2.9 ? 1.1
2y
TABLE 3. Continued
The Journal of Thoracic and Cardiovascular SurgerycVolume 139, Number 61525
ACD
Yan et al Acquired Cardiovascular Disease

Page 8

with accumulating number of patients. In the earlier reports,
Cribier and colleagues6reported a procedural success rate of
82% in 33 patients received Cribier-Edwards prosthesis.6
Grube and collaborators22obtained a procedural success
rate of 84% using the first- and second-generation Core-
Valve devices. Webb and colleagues9demonstrated proce-
dural success increased from 76% in the first 25 patients
to 96% in the subsequent 25 patients and an associated de-
crease in30-day mortality from 16% to8%, respectively.In
a recent multicenter study on 646 patients receiving the
third-generation CoreValve, the overall procedural success
rate was 97%, and the 30-day all-cause mortality was
8%.31Main aspects of the learning curve for TAV interven-
tion are device technology, procedural skills, and decision
making involving case selection, intraprocedural strategic
plans, and alterations as well as decision making in manage-
ment of complications. At this stage, the number of patients
required to regard a specialized center well trained is not cer-
tain.Thisprocedurerequiresahighleveloftraining,expertise,
andinfrastructuretooptimizesafetyforbothstaffandpatients.
Therefore, concentration of the services at centers with expe-
rience is likely to increase quality of care for these patients.
Second, the short-term efficacy based on echocardiogra-
phy measurements and NYHA functional class for patients
who had successful TAV, irrespective of the procedural ap-
proach used, seems to be encouraging. Based on the limited
data available, echocardiography measurements at 1-, 6-,
and 12-month follow-up did not demonstrate significant
functional deterioration. However, long-term follow-up
data are not available and the durability of the prostheses
is uncertain. Assessment of the long-term durability will
require at least 5 years of follow-up. Given the limited life
expectancy of patients currently considered for TAV, this
may not be practical. It is also noted that although there
are significant improvements in valve hemodynamic perfor-
mance and echocardiography findings, impact on patients’
quality of life is less clear.
Currently, TAV is restricted to elderly patients who are
considered at very high risk for conventional surgery. In
a joint position statement published in 2005, the Society
of Thoracic Surgeons, the American Association for Tho-
racic Surgery, and the Society for Cardiovascular Angiog-
raphy and Interventions cautioned against the widespread
use of these technologies without proper evaluation.36In
the absence of published guidelines, the selection of cases
must be multidisciplinary. All studies evaluated aimed to
recruit patients at ‘‘high surgical risk’’ or ‘‘nonsurgical’’
candidates with AS. The eligibility of patients for TAV
is poorly defined or not reported in 4 studies,9,13,16,23
and in the other studies, the operability is mostly based
on assessment by clinicians, supplemented with informa-
tion obtained from an operative risk score, mostly the
EuroSCORE, which provides an estimation of the opera-
tive mortality risk.
However, the validity of this risk tool for estimating the
surgical risk incurred by high-risk patients has been
TABLE 4. Echocardiography measurements and clinical data following transcatheter aortic valve implantation
Studyn
Mean aortic
valve area before
TAV (cm2) ± SD
Mean aortic
valve area after
TAV (cm2) ± SD
Peak pressure gradient
before TAV
(mm Hg) ± SD
Peak pressure gradient
after TAV
(mm Hg) ± SD
Mean pressure gradient
before TAV
(mm Hg) ± SD
Antegrade Edwards valve
Rouen6
Retrograde Edwards valve
Vancouver9
Paris11
Athens12
Quebec13
Transapical Edwards valve
Vancouver16
Leipzig18
Frankfurt19
Multicenter20
Bicenter21
Retrograde CoreValve valve
Siegburg22
Brighton23
Montreal25
Rotterdam27
Catania29
Multicenter30
Multicenter31
330.6 ? 0.11.7 ? 0.1—— 37 ? 13
50
12
12
22
0.6 ? 0.2
0.5 ? 0.1
0.6 ? 0.1
0.6 ? 0.2
1.7 ? 0.4
1.7 ? 0.5
1.8 ? 0.1
1.5 ? 0.3
—
—
—
—
46 ? 17
50 ? 19
57 ? 23
34 ? 10
91 ? 33
56 ? 15
22 ? 7
17 ? 5
26
50
26
59
40
0.5 ? 0.1
—
0.6 ? 0.1
0.5 ? 0.2
0.6 ? 0.1
1.7 ? 0.5
—
—
—
1.6 ? 0.4
—
—
—
—
—45 ? 14
—
—
—
40 ? 10
15 ? 7
—
18 ? 11
15 ? 565 ? 15
25
12
11
33
30
86
646
0.7 ? 0.1
—
0.6 ? 0.2
0.8 ? 0.2
0.6 ? 0.2
0.6 ? 0.2
0.6 ? 0.2
—
—
70 ? 14
—
—
77 ? 28
86 ? 22
71 ? 23
78 ? 26
21 ? 5
—
—
20 ? 12
—
—
—
44 ? 11
—
51 ? 19
46 ? 16
58 ? 18
44 ? 15
49 ? 14
1.3 ? 0.4
2.0 ? 0.9
1.5 ? 0.4
—
—
TAV, Transcatheter aortic valve; NYHA, New York Heart Association; SD, standard deviation.
1526The Journal of Thoracic and Cardiovascular SurgerycJune 2010
ACD
Acquired Cardiovascular DiseaseYan et al

Page 9

criticized. Recent observational data indicate that the Euro-
SCORE severely overestimates operative risk in high-risk
patients having isolated surgical AVR.37,38In surgical series
from the Mayo Clinic, an estimated 30-day mortality of
23.6% was significantly higher than an observed mortality
of only 5.8%.37By comparison, Cribier and associates6
enrolled patients with a mean predicted operative risk of
12 ? 2 for TAV implantation and experienced a 30-day
mortality of 18%.6Grube and colleagues30conducted
a multi-institutional study using the CoreValve percutane-
ous aortic valve on 86 patients with a EuroSCORE of 22
? 13 and achieved 30-day mortality of 12%. This implies
that patients with AS who are considered at high risk for
conventional AVR may actually present lower mortality
rates if treated surgically than if treated by means of TAV
insertion. Clinicians must be cautious in estimating opera-
tive risk from models that were not intended for this specific
use. The definition of ‘‘high surgical risk’’ is difficult, as
evidenced by the conversion of such patients to open
AVR after failure of TAV implantation. In the multicenter
study by Grube and colleagues,306 patients required emer-
gency conversion to open procedure to retrieve the devices
and successfully implanted aortic prostheses with only 1
operative death.
We attempted to evaluate the durability of TAV, but there
is a lack of comparative studies and the data on long-term ef-
ficacy and durability of TAV in the current literature. The
relatively unproven nature and inherent risks of this new
therapy mandate a formal team approach to patient selection
and outcome analysis. The inclusion and exclusion criteria
of the PARTNER trial provide some indication of the limits
of this new technology. Before further convincing evidence
becomes available, the use of TAV implantation should be
considered only within the boundaries of clinical trials
with special arrangements for clinical governance, consent,
and audit or research. Decision on eligibility must be indi-
vidualized and assessed by a multidisciplinary team of car-
diologists, cardiac surgeons, and cardiac anesthesiologists.
It is likely that progressive development of technology, fa-
miliarity withtechniques,andbetterunderstandingofappro-
priate criteria for patient selection will continue to refine the
indications for TAV procedures.
References
1. IungB,BaronG,ButchartEG,DelahayeF,Gohlke-Ba ¨rwolfC,LevangOW,etal.
A prospective survey of patients with valvular heart disease in Europe: The Euro
Heart Survey on Valvular Heart Disease. Eur Heart J. 2003;24:1231-43.
2. Carabello BA, Paulus W. Aortic stenosis. Lancet. 2009;372:956-66.
3. Schwarz F, Baumann P, Manthey J, Hoffmann M, Schuler G, Mehmel HC, et al.
Theeffect of aortic valve replacement on survival. Circulation. 1982;66:1105-10.
4. Cribier A, Eltchaninoff H, Tron C, Bauer F, Agatiello C, Sebagh L, et al. Early
experience with percutaneous transcatheter implantation of heart valve prosthesis
for the treatment of end-stage inoperable patients with calcific aortic stenosis.
J Am Coll Cardiol. 2004;43:698-703.
5. Bauer F, Eltchaninoff H, Tron C, Lesault PF, Agatiello C, Nercolini D, et al.
Acute improvement in global and regional left ventricular systolic function after
percutaneous heart valve implantation in patients with symptomatic aortic steno-
sis. Circulation. 2004;110:1473-6.
6. Cribier A, Eltchaninoff H, Tron C, Bauer F, Agatiello C, Nercolini D, et al. Treat-
ment of calcific aortic stenosis with the percutaneous heart valve: mid-term fol-
low-up from the initial feasibility studies: the French experience. J Am Coll
Cardiol. 2006;47:1214-23.
Mean pressure gradient
after TAV
(mm Hg) ± SD
LVejection
fraction before
TAV (%) ± SD
LVejection
fraction after
TAV (%) ± SD
NYHA functional
class improved
vs baseline, n (%)
Patients at risk at
6-mo follow-up,
n (%)
Patients at risk at
12-mo follow-up,
n (%)
Death at
6 mo, n (%)
9 ? 2 45 ? 1853 ? 1421 (64)11 (33) 5 (15)16 (48)
11 ? 5
11 ? 3
10 ? 3
9 ? 3
53 ? 15
47 ? 16
—
51 ? 16
57 ? 13
—
—
54 ? 11
25 (50)
7 (58)
12 (100)
17 (77)
35 (70)
9 (75)
—
10 (45)
17 (34)
—
—
—
9 (18)
3 (25)
—
—
9 ? 5
7 ? 4
6 ? 2
9 ? 6
8 ? 3
56 ? 13
53 ? 14
—
47 ? 16
52 ? 15
63 ? 9
—
—
—
55 ? 19
Most
—
—
—
—
17 (65)
37 (74)
—
15 (25)
—
17 (65)
36 (72)
—
5 (8)
—
9 (35)
13 (26)
—
13 (22)
13 (33)
12 ? 3
—
9 ? 4
12 ? 7
9 ? 4
9
3 ? 2
54 ? 16
—
49 ? 17
41 ? 12
53 ? 8
54 ? 16
52 ? 14
—
—
18 (72)
—
11 (100)
—
—
—
—
7 (28)
—
1 (9)
—
13 (43)
—
—
2 (8)
—
1 (9)
—
5 (17)
—
—
—
—
5 (45)
—
—
—
—
56 ? 11
46 ? 15
—
—
—
TABLE 4. Continued
The Journal of Thoracic and Cardiovascular SurgerycVolume 139, Number 61527
ACD
Yan et al Acquired Cardiovascular Disease

Page 10

7. Eltchaninoff H, Tron C, Bauer F, Brunet D, Baala B, Drogoul L, et al. Aortic bio-
prosthesis implanted percutaneously: three year follow up. Arch des Maladies du
Coeur et des Vaisseaux. 2007;100:901.
8. Webb JG, Chandavimol M, Thompson CR, Ricci DR, Carere RG, Munt BI, et al.
Percutaneous aortic valve implantation retrograde from the femoral artery. Circu-
lation. 2006;113:842-50.
9. Webb JG, Pasupati S, Humphries K, Thompson C, Altwegg L, Moss R, et al. Per-
cutaneous transarterial aortic valve replacementinselected high-riskpatientswith
aortic stenosis. Circulation. 2007;116:755-63.
10. Ree RM, Bowering JB, Schwarz SKW. Case series: anesthesia for retrograde per-
cutaneous aortic valve replacement—experience with the first 40 patients. Can J
Anesth. 2008;55:761-8.
11. Descoutures F, Himbert D, Lepage L, Iung B, Detaint D, Tchetche D, et al. Con-
temporary surgical or percutaneous management of severe aortic stenosis in the
elderly. Eur Heart J. 2008;29:1410-7.
12. Spargias K, Manginas A, Pavlides G, Khoury M, Stavridis G, Rellia P, et al.
Transcatheter aortic valve implantation: first Greek experience. Hellenic J Car-
diol. 2008;49:397-407.
13. Rodes-CabauJ,DumontE,DeLaRochelliereR,DoyleD,LemieuxJ,BergeronS,
et al. Feasibility and initial results of percutaneous aortic valve implantation in-
cluding selection of the transfemoral or transapical approach in patients with se-
vere aortic stenosis. Am J Cardiol. 2008;102:1240-6.
14. Lichtenstein SV, Cheung A, Ye J, Thompson CR, Carere RG, Pasupati S, et al.
Transapical transcatheter aortic valve implantation in humans: initial clinical ex-
perience. Circulation. 2006;114:591-6.
15. Ye J, Cheung A, Lichtenstein SV, Pasupati S, Carere RG, Thompson CR, et al.
Six-month outcome of transapical transcatheter aortic valve implantation in the
initial seven patients. Eur J Cardiothorac Surg. 2007;31:16-21.
16. Ye J, Cheung A, Lichtenstein SV, Altwegg LA, Wong DR, Carere RG, et al.
Transapical transcatheter aortic valveimplantation:1-year outcomein26patients.
J Thorac Cardiovasc Surg. 2009;137:167-73.
17. Walther T, Falk V, Borger MA, Dewey T, Wimmer-Greinecker G, Schuler G,
et al. Minimally invasive transapical beating heart aortic valve implantation—
proof of concept. Eur J Cardiothorac Surg. 2007;31:9-15.
18. Walther T, Falk V, Kempfert J, Borger MA, Fassl J, Chu MWA, et al. Transapical
minimally invasive aortic valve implantation; the initial 50 patients. Eur J Cardi-
othorac Surg. 2008;33:983-8.
19. Zierer A, Wimmer-Greinecker G, Martens S, Moritz A, Doss M. The transapical
approach for aortic valve implantation. J Thorac Cardiovasc Surg. 2008;136:
948-53.
20. Walther T,SimonP,DeweyT,Wimmer-GreineckerG,FalkV,Kasimir MT,etal.
Transapical minimallyinvasive aortic valve implantation: multicenter experience.
Circulation. 2007;116(11 Suppl 1):I240-5.
21. Svensson LG, Dewey T, Kapadia S, Roselli EE, Stewart A, Williams M, et al.
United States feasibility study of transcatheter insertion of a stented aortic valve
by the left ventricular apex. Ann Thorac Surg. 2008;86:46-55.
22. Grube E, Laborde JC, Gerckens U, Felderhoff T, Sauren B, Buellesfeld L, et al.
Percutaneous implantation of the CoreValve self-expanding valve prosthesis in
high-risk patients with aortic valve disease: the Siegburg first-in-man study. Cir-
culation. 2006;114:1616-24.
23. Behan M, Haworth P, Hutchinson N, Trivedi U, Laborde JC, Hildick-Smith D.
Percutaneous aortic valve implants under sedation: our initial experience. Cathe-
ter Cardiovasc Interv. 2008;72:1012-5.
24. Marcheix B, Lamarche Y, Berry C, Asgar A, Laborde JC, Basmadjian A, et al.
Surgical aspects of endovascular retrograde implantation of the aortic CoreValve
bioprosthesisinhigh-riskolderpatientswithseveresymptomaticaortic stenosis.J
Thorac Cardiovasc Surg. 2007;134:1150-6.
25. Berry C, Asgar A, Lamarche Y, Marcheix B, Couture P, Basmadjian A, et al.
Novel therapeutic aspects of percutaneous aortic valve replacement with the
21F CoreValve Revalving system. Catheter Cardiovasc Interv. 2007;70:610-6.
26. Berry C, Oukerraj L, Asgar A, Lamarche Y, Marcheix B, Denault AY, et al. Role
of transesophageal echocardiography in percutaneous aortic valve replacement
with the CoreValve revalving system. Echocardiography. 2008;25:840-8.
27. De JaegerePP,Piazza N,Galema TW, Otten A,SolimanOI,VanDalen BM,etal.
Early echocardiographic evaluation following percutaneous implantation with the
self-expanding CoreValve Revalving System aortic valve bioprosthesis. Euroin-
tervention. 2008;4:351-7.
28. Otten AM, van Domburg RT, van Gameren M, Kappetein AP, Takkenberg JJ,
Bogers AJ, et al. Population characteristics, treatment assignment and survival
of patients with aortic stenosis referred for percutaneous valve replacement. Euro-
intervention. 2008;4:250-5.
29. Tamburino C, Capodanno D, Mul EM, Scarabelli M, Cammalleri V, Barbanti M,
et al. Procedural success and 30-day clinical outcomes after percutaneous aortic
valve replacement using current third-generation self-expanding CoreValve pros-
thesis. J Invasive Cardiol. 2009;21:99-100.
30. Grube E, Schuler G, Buellesfeld L, Gerckens U, Linke A, Wenaweser P, et al. Per-
cutaneous aortic valve replacement for severe aortic stenosis in high-risk patients
usingthesecond-andcurrentthird-generationself-expandingCoreValveprosthesis.
Device success and 30-day clinical outcome. J Am Coll Cardiol. 2007;50:69-76.
31. Piazza N, Grube E, Gerckens U, den Heijer P, Linke A, Luha O, et al. Procedural
and 30-day outcomes following transcatheter aortic valve implantation using the
third generation (18Fr) CoreValve revalvingsystem: results from themulticentre,
expanded evaluation registry 1-year following CE mark approval. Eurointerven-
tion. 2008;4:242-9.
32. Astor BC, Kaczmarek RG, Hefflin B, Daley WR. Mortality after aortic valve re-
placement: results from a nationally representative database. Ann Thorac Surg.
2000;70:1939-45.
33. Fish DR. Percutaneous heart valve replacement. Enthusiasm tempered. Circula-
tion. 2004;110:1876-78.
34. NHS Centre for Reviews and Dissemination. Undertaking systemic reviews of re-
search on effectiveness: CRD’s guidance for those carrying out or commissioning
reviews. CRD Report 4. 2nd ed. York: NHS Centre for Reviews and Dissemina-
tion; 2001.
35. Cribier A, Eltchaninoff H, Bash A, Borenstein N, Tron C, Bauer F, et al. Percu-
taneous transcatheter implantation of an aortic valve prosthesis for calcific aortic
stenosis: first human case description. Circulation. 2002;106:3006-8.
36. Vassiliades TA Jr, Block PC, Cohn LH, Adams DH, Borer JS, Feldman T, et al.
The clinical development of percutaneous heart valve technology. J Thorac Car-
diovasc Surg. 2005;129:970-6.
37. Brown ML, Schaff HV, Sarano ME, Li Z, Sundt TM, Dearani JA, et al. Is the Eu-
ropean System for Cardiac Operative Risk Evaluation model valid for estimating
the operative risk of patients considered for percutaneous aortic valve replace-
ment? J Thorac Cardiovasc Surg. 2008;136:566-71.
38. Grossi EA, Schwartz CF, Yu P, Jorde UP, Crooke GA, Grau JB, et al. High-risk
aortic valve replacement: are the outcomes as bad as predicted? Ann Thorac Surg.
2008;85:102-7.
1528The Journal of Thoracic and Cardiovascular SurgerycJune 2010
ACD
Acquired Cardiovascular DiseaseYan et al