European real world trans-catheter aortic valve implantation: systematic review and meta-analysis of European national registries
Krasopoulos et al. Journal of Cardiothoracic Surgery
European real world trans-catheter aortic valve implantation: systematic review and meta-analysis of European national registries
G. Krasopoulos 0
F. Falconieri 0
U. Benedetto 0
J. Newton 0
R. Sayeed 0
R. Kharbanda 0
A. Banning 0
0 Oxford Heart Centre, Oxford University Hospitals , Headley Way, Headington, Oxford OX3 9DU , UK
Objective: Transcatheter aortic valve implantation (TAVI) has been adopted rapidly in Europe. TAVI national registries can augment understanding of technologies and represent real-world experience, providing further clinical insights. We undertook a meta-analysis of published European national TAVI registries to assess current results following TAVI in Europe. Methods: Electronic databases were searched. The review focused on the comparison of the following TAVI strategies: transfemoral (TF) and transapical (TA) SAPIEN and CoreValve implantation. Individual event rates for outcomes of interest were pooled using a mixed effect model. Results: Seven European national TAVI registries (UK, Swiss, Belgium, Italy, Spain, France, Germany) were identified, including a total of 9786 patients who received TF-SAPIEN (n = 2885), TA-SAPIEN (n = 2252) and CoreValve (n = 4649) implantation. Pooled incidence of 30-day mortality was 0.08% [95% Confidence Interval (CI): 0.05-0.11], 0.12% [95% CI: 0.07-0.19] and 0.06% [95% CI: 0.03-0.11] for TF-SAPIEN, TA-SAPIEN and CoreValve respectively (test for subgroup difference P = 0.18); there was high heterogeneity across European countries. Pooled incidence of stroke was comparable among the TAVI strategies (test for subgroup difference P = 0.79); the incidence of post-procedural moderate paravalvular leak ≥ 2 (P = 0.9) was similar across groups. CoreValve implantation was associated with an increased risk of pacemaker implantation (0.22 [95% CI: 0.19-0.26]; test for subgroup difference P < 0.0001). The lowest 30-day mortality was associated with TAVI performed in Spain (b coefficient −4.3; P = 0.03), in Italy (b coefficient −2.1; P < 0.0001), in UK (b coefficient −1.95; P = 0.01) and in France (b coefficient −2.8; P = 0.03). The German registry has the highest mortality for every TAVI strategy amongst all other European registries and especially for the TA-SAPIEN group. Conclusions: Transarterial TAVI approaches were associated with a low early mortality regardless of the type of device used. There was marked heterogeneity among European countries for early mortality.
Transcatheter aortic valve implantation; TAVI; TAVR; Aortic stenosis; Registry; Metanalysis
Dr Alain Cribier reported the first transcatheter aortic
valve implantation (TAVI) procedure in 2002 . Following
the randomized trials Placement of Aortic Transcatheter
Valves (PARTNER) A and B [2, 3], TAVI is now considered
the standard of care for symptomatic patients with aortic
valve stenosis that are either high-risk or have been turned
down for conventional aortic valve replacement .
However, even within these groups, the patients enrolled into
the trials were highly selected, and therefore may not
reflect real-world patients requiring treatment.
In Europe patients who undergo TAVI are recorded
into national databases which capture the majority of
the high risk or inoperable cases, due to co-morbidities
and/or frailty patients. Their analysis can therefore
provide further insight and evidence into the effectiveness
of TAVI in the real-world clinical practice of
symptomatic patients with aortic stenosis who are not candidates
for conventional aortic valve replacement due to
comorbidities and/or frailty . Furthermore, mixed
national registries report country specific results that may
be affected by variations in national health policy and
local referral practice, device performance and
definitions thus accounting for otherwise inexplicable
differences in outcome and complications.
The aim of this study is to obtain an insight into the
role of TAVI in the treatment of high-risk patients with
aortic stenosis in Europe by conducting a meta-analysis
of European national registries, focusing on the three
most commonly used TAVI procedures : the
transfemoral and transapical balloon-expandable Edwards
SAPIEN transcatheter heart valve (Edwards Lifesciences,
Irvine, CA, USA) and the self-expanding Medtronic
CoreValve (Medtronic, Minneapolis, MN, USA).
Inclusion criteria for this meta-analysis were (1) All
European national registries reporting outcomes of
patients undergoing TAVI; (2) TAVI procedures should
have been performed using transfemoral (TF SAPIEN)
and/or transapical (TA SAPIEN) balloon-expandable
Edwards SAPIEN transcatheter heart valve and/or
self-expanding Medtronic CoreValve.
Care was taken to ensure that studies selected did not
result in duplication of data. Non-English language,
review articles, and editorials were excluded. Studies that
did not separate results for TF SAPIEN, TA SAPIEN
and CoreValve were also excluded.
A literature search was done on the 1st of September 2014
using MEDLINE, EMBASE, and Web of Science to
identify relevant articles. Search terms used the controlled
vocabularies of MEDLINE and EMBASE alone or in
combination with text words including “transcatheter aortic
valve implantation”, “TAVI”, “registry”, “Europe”.
References from the selected studies were manually searched to
identify any other potentially suitable publications.
Two reviewers independently screened all studies for
inclusion. Disagreements were resolved by consensus.
Agreement between reviewers regarding study inclusion
was assessed using the Cohen k statistic.
All included studies were interrogated for the following
endpoints: 30-day and one year mortality, incidence of
stroke, incidence of pacemaker implantation and
presence of post deployment moderate paravalvular leak (≥2,
according to authors definition).
Mixed effects meta-analysis was performed pooling all
single registry proportions using the
DerSimonianLaird estimate for all outcomes according to the TAVI
strategy used. The I2 statistic was used to assess the
heterogeneity across the reported results. I2 values of
25 to 49%, 50 to 74%, and 75% or greater were used
to indicative low, moderate, and high levels of
heterogeneity . Cochrane Q statistic was used as test for
subgroup differences (random effects model). The
multivariate meta-regression (mixed model) used was
used to adjust the effect of different TAVI strategies
for the following risk factors: patients risk profile
according to mean Logistic Euroscore , the reporting
European country, the total number of centres
involved and the sponsorship of the registry by a TAVI
valve manufacturer. R2 was used to estimate the
amount of heterogeneity accounted for in the
multivariate model. Publication bias was assessed using
Begg & Mazumdar test. Trim-and-fill method was
used for estimating and adjusting for the number and
outcomes of missing studies. A p < 0.05 was used as
the level of significance and 95% confidence intervals
(95% CI) have been reported where appropriate.
R version 3.1.0 (R Core Team (2014
http://www.R-project.org/.) and meta package (Guido Schwarzer (2014)
http://CRAN.R-project.org/package=meta) were used for
all statistical analyses.
our eligibility criteria and were selected for the systematic
review and meta-analysis [8–15]. The studies are
summarized in Table 1 and depicted in Fig. 1. A Cohen k statistic
of 90% was obtained for the final selection process.
Seven European national TAVI registries (Belgium,
France, Germany, Italy, Spain, Swiss, UK) were
identified including 9786 patients which have received TF
SAPIEN (n = 2885), TA SAPIEN (n = 2252) and CoreValve
(n = 4649) implantation. All but Italian and Swiss registries
reported on all three strategies. Two different and
independent Italian TAVI registries reported on TA SAPIEN
and CoreValve implantation separately. The Swiss registry
reported on TF SAPIEN and CoreValve only. Mean
logistic EuroSCORE ranged from 16% (Spain registry,
CoreValve group) to 33% (Belgian registry, TA SAPIEN
The pooled estimate for 30-day mortality (Fig. 2) was
0.08 [95% CI: 0.05–0.11], 0.12 [95% CI: 0.07–0.19] and
0.06 [95% CI: 0.03–0.11] for TF SAPIEN™, TA SAPIEN
and CoreValve respectively (test for subgroup difference
P = 0.18). High heterogeneity was present among
registries for all three strategies: TF SAPIEN (I2 = 86.6%), TA
SAPIEN (I2 = 93.3%) and CoreValve (I2 = 97%). In
multivariate meta-regression the increased risk for 30-day
mortality was independently associated with TA SAPIEN
Table 1 European registries overview
FRANCE 2 TAVI Registry 
German TAVI Registry 
Italian Registry TA TAVI 
Italian Multicenter CoreValve Registry 
Spain TAVI Registry 
SWISS TAVI Registry 
UK TAVI Registry 
TAVI transcatheter aortic valve implantation, TF transfemoral, TA transapical, UK United Kingdom
strategy (b coefficient 0.60; P = 0.001). A higher 30-day
mortality was reported from registries with higher number
of centres involved into the national TAVI program (b
coefficient 0.14; P = 0.03). The lowest 30-day mortality was
associated with TAVI performed in Spain (b coefficient
−4.3; P = 0.03), in Italy (b coefficient −2.1; P < 0.0001), in
UK (b coefficient −1.95; P = 0.01) and in France (b
coefficient −2.8; P = 0.03). The German registry has the highest
mortality for every TAVI strategy amongst all other
European registries and especially for the TA SAPIEN group.
Patients risk profile assessed by the mean Logistic
EuroSCORE was not associated with observed 30-day mortality
(P = 0.9, Fig. 3, left). Moderators included in the
multivariate model accounted for 98% amount of heterogeneity
with no significant residual heterogeneity (P = 0.25). No
publication bias was detected (P = 0.31).
Pooled estimate for the incidence of stroke (Fig. 4) was
0.03 [95% CI: 0.03–0.04], 0.03 [95% CI: 0.02–0.05] and
0.03 [0.02–0.04] for TF SAPIEN™, TA SAPIEN and
CoreValve respectively (test for subgroup difference P = 0.79).
High heterogeneity was found among registries for TA
SAPIEN (I2 = 81.2%) whilst TF SAPIEN and CoreValve
were associate with low heterogeneity for stroke incidence
(I2 = 0% and I2 = 32.6% respectively). The lowest incidence
of stroke was associated with TAVIs performed in Italy (b
coefficient −1.5; P = 0.02). Patients risk profile assessed by
Fig. 1 Outline of the systematic review process
the mean Logistic EuroSCORE was not associated with
the incidence of stroke (P = 0.74). Moderators included in
the multivariate model accounted for 82.4% amount of
heterogeneity with no significant residual heterogeneity
(P = 0.32). No publication bias were detected (P = 0.27).
Need for pacemaker implantation
Pooled estimate for incidence of pacemaker
implantation (Fig. 5) was 0.08 [95% CI: 0.05–0.11], 0.07 [95%
CI: 0.04–0.11] and 0.22 [95% CI: 0.19–0.26] for TF
SAPIEN™, TA SAPIEN and CoreValve respectively
(test for subgroup difference P < 0.0001). High
heterogeneity was found among registries for TF SAPIEN
(I2 = 80.9%), TA SAPIEN (I2 = 88.8%) and CoreValve
(I2 = 83%) technologies. TF SAPIEN (b coefficient
−1.2; P < 0.0001) and TA SAPIEN (b coefficient −1.08;
P = 0.001) were independently associated with the
lowest risk of pacemaker implantation. Patients risk
profile assessed by the mean Logistic EuroSCORE was
not associated with the rate of pacemaker
implantation (P = 0.78). Moderators included in the multivariate
model accounted for 90.5% amount of heterogeneity but
significant residual heterogeneity was found (P = 0.02). No
publication bias was detected (P = 0.08).
Post implantation paravalvular leak
There was no significant difference in the incidence
of moderate paravalvular leak (≥2): 0.07 [95% CI:
0.05–0.11], 0.06 [95% CI: 0.05–0.08] and 0.07 [95%
CI: 0.04–0.12] for TF SAPIEN™, TA SAPIEN and
CoreValve respectively (Fig. 6). (P = 0.9). High
heterogeneity was found among registries for TF SAPIEN (I2 =
84.7%) and CoreValve (I2 = 94.4%) but not for TA
SAPIEN (I2 = 29.1%). However, there was a significant
publication bias (P = 0.002) and trim and fill method
suggested an overall prevalence of aortic paravalvular
leak of 0.10 [95% CI: 0.0767–0.131].
1 year mortality
Pooled estimate for incidence of 1 year mortality (Fig. 7)
was 0.15 [95% CI: 0.14–0.16], 0.23 [95% CI: 0.19–0.28]
and 0.17 [95% CI: 0.15–0.19] for TF SAPIEN™, TA
Fig. 2 Meta-analysis for proportions of 30-day mortality
SAPIEN and CoreValve respectively (test for subgroup
difference P = 0.0008). High heterogeneity was found
among registries for TA SAPIEN (I2 = 81.9%) and
CoreValve (I2 = 59.3%) but not for TF SAPIEN (I2 =
0%). At multivariate meta-regression, mean Logistic
EuroSCORE was moderately associated with all-cause
mortality at one year (b coefficient 0.07; P = 0.06,
Fig. 3 right). Different TAVI strategies did not impact
on the 1-year mortality (TF SAPIEN versus
CoreValve: b coefficient −0.1428; P = 0.07) and TA SAPIEN
versus CoreValve: b coefficient 0.1515; P = 0.3).
Moderators included in the multivariate model accounted
for 100% amount of heterogeneity and no significant
residual heterogeneity was found (P = 0.48). No
publication bias was detected (P = 0.25).
This meta-analysis of all published European
TAVIregistries provides an insight to the real world practice
of TAVI in the western world. The results support the
superiority of the transarterial approach, regardless of
the type of implantation device used. CoreValve was
associated with > 2 fold increased risk for pacemaker
implantation. There was a marked heterogeneity among
European countries for all short-term outcomes
investigated. Logistic EuroSCORE, which is widely adopted in
Europe to select patients at high-risk for surgical AVR,
failed to predict 30-day mortality but it was moderately
associated with 1-year mortality.
The present meta-analysis found that the overall
European TAVI clinical practice has a 30-day mortality of 8%
Fig. 3 Bubble plot. Display the adjusted association between logistic EuroSCORE, 30-day mortality (left) and 1-year mortality (right)
which is higher than the mortality reported by the
randomized trials (PARTNER trial A: 3.4% for TF-TAVI,
PARTNER trial B: 5% for TF-TAVI and STACCATO
trial : 5.8% in TA-TAVI). The inclusion of unselected
patients with higher risk profile (mainly severe
peripheral disease) in the TA SAPIEN group might partially
explain the inferior outcomes and the higher 30-day
mortality (12%) for this group.
Particularly with regards to the German registry, there
is a substantial difference in mortality across all TAVI
strategies and in particular in relation to the TA SAPIEN
group, which is difficult to explain in isolation. This may
Fig. 4 Meta-analysis for proportions of stroke
Fig. 5 Meta-analysis for proportions of pacemaker requirement
be due to the fact that the German registry is reporting
the initial period of introduction of the technique which
may not be a true representation of the current status.
Isolated published series have independently reported
lower mortality for TA-TAVI [17, 18].
It was also evident that, the more concentrated the
program was to a limited number of centres, the lower
the reported 30-day mortality was for the corresponded
country, suggesting that TAVI should be offered by a
restricted and highly specialised centres.
Logistic EuroSCORE was not associated with 30-day
mortality in the present analysis. It is widely recognized
that the logistic EuroSCORE is not an ideal tool for
measuring the pre-procedural risk of TAVI as the
predicted mortality is grossly overestimated . The
present analysis found that early mortality after TAVI
varied significantly across European countries, regardless
of the type of strategy used. These discrepancies might
be partially explained by national differences in patient
selection, not accounted for by the logistic EuroSCORE
Fig. 7 Meta-analysis for proportions of 1-year mortality
but also by other factors like team integration and
learning curve, use of general versus local anaesthesia and
level of postoperative care. The presence of
heterogeneity in early mortality across European countries
highlights the urgent need for standardization of patient
selection criteria for TAVI.
The incidence of stroke after TAVI in PARTENR A & B
and the STACCATO trials was 5.5, 6.7 and 8.8%
respectively. Our meta-analysis has revealed the European
incidence of stroke after TAVI is 3.0%, regardless of the TAVI
strategy used. This result is encouraging considering the
risk of peri-operative stroke following surgical AVR in
elderly patients, which is ranging from 3 to 7% .
This analysis has also confirmed that CoreValve is
associated with an increased rate of pacemaker
implantation when compared to the SAPIEN valve (8%).
However, the rate of pacemaker implantation in patients
receiving SAPIEN valve was higher than those reported
in the PARTNER A (3.8%) and B (3.4%) trials. This
could be a reflection of the increased anatomic
complexity for TAVI in the real-world practice.
This meta-analysis has reported an overall 7%
incidence of moderate paravalvular leak (≥2) is better than
that the one reported in PARTNER A (12.2%) and B
(11.8%) trials. The standardisation of techniques and the
increasing familiarity with the procedures with better
understanding of deployment strategies may have
influence the reduction in the incidence of moderate
paravalvular leak, which is the most important complication
that negatively influences the long term outcome after
TAVI . However, there is an absence of standardized
in definition and quantification of paravalvular leak after
TAVI (i.e. angiography versus echocardiography,
qualitative or semi-quantitative) which needs to be addressed.
Finally, the logistic EuroSCORE was the only
moderator marginally associated with 1-year mortality,
suggesting that mid-term outcome after TAVI is more
“patient-related” rather than “procedure-related”.
This manuscript has a number of limitations; there is
a marked heterogeneity in the reported data, which
reflect differences in practice, data collection and data
analysis. Patient level data were not disclosed and as such,
any attempt to analyse further the observed differences
is not possible. We understand and acknowledge that
meta-analysis of data from different registries remains
inferior to RCT. Finally; there is an inherited lack of
surgical comparator that makes it difficult for the reader to
formulate clear opinion on the subject.
In conclusion, this meta-analysis of European TAVI
registries is reporting higher 30-day mortality than that
reported by the published randomized trials, in
particular after transapical TAVIs. This result may reflect the
inclusion of patients with a higher risk profile. The
evidence suggests that transarterial TAVI should be the
preferred valve implantation strategy, whenever possible.
The significant heterogeneity in early mortality across
European countries suggests that there in an urgent
need for standardization of patient selection process and
procedural aspects in order to optimise outcomes and
guarantee high standards of care, across European
countries. Despite the fact that in Europe patients are
currently selected for TAVI on the basis of their surgical
risk measured by the logistic EuroSCORE (≥20%), such a
risk stratification system is ineffective in predicting early
mortality after TAVI. European registries of TAVI and
surgical AVR (with clear differentiation amongst
conventional, minimally invasive and suture-less
minimally invasive surgical AVR) may be used to generate a
well-powered TAVI-weighted risk score.
Availability of data and materials
Please contact author for data requests.
All authors contributed equally to the writing of this manuscript. GK and UB
were additionally responsible for the data collection and the statistical
analysis. All authors read and approved the final manuscript.
G. Krasopoulos, F. Falconieri, U. Benedetto, R. Sayeed, J. Newton and R.
Kharbanda declare that they have no competing interests. A. Banning: has
received institutional funding for a fellowship from Boston Scientific Corp.
Consent for publication
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