8 Zdrav Vestn | januar – februar 2017 | Letnik 86
Srce in ožiLje
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
1 University Medical 
Centre Maribor, Maribor, 
Slovenia
2 Department of 
Cardiology, Vivantes 
Klinikum im 
Friedrichshain und Am 
Urban, Berlin, Germany
3 Rostock University 
Medical Center, Rostock, 
Germany
4 Department of Cardiac 
Surgery, Deutsches 
Herzzentrum Berlin, 
Berlin, Germany
Korespondenca/
Correspondence:
Anže Djordjević MD,
e: anze.djordjevic@gmail.
com
Ključne besede:
TAVi; bikuspidna; aortna; 
zaklopka
Key words:
TAVi; bicuspid; aortic; 
valve
Citirajte kot/Cite as:
Zdrav Vestn. 2017;  
86(1–2):8–18
Srce in ožiljeizvirni znanstveni članek
Transcatheter aortic valve implantation 
for bicuspid aortic valve stenosis: Acute 
and intermediate-term outcomes in a high 
volume institution
Transkatetrska vstavitev aortne zaklopke pri bolnikih s 
stenozo bikuspidne aortne zaklopke: kratko- in srednjeročni 
rezultati v ustanovi z velikim obratom bolnikov
Anže Djordjević,1 Giuseppe D’Ancona,2,3 Axel Unbehaun,4 Stephan Kische,2,3  
Hüseyin ince,2,3 Miralem Pašić4
Izvleček
Izhodišče: Prikazujemo rezultate naše skupine bolnikov z bikuspidno aortno (BAV) stenozo, ki smo 
jim perkutano vstavili umetno aortno zaklopko.
Metode: Retrospektivno smo analizirali perioperativne podatke in podatke s kontrolnih pregledov. 
Vsi bolniki so bili zdravljeni z metodo transkatetrske vstavitve aortne zaklopke (angl. transcatheter 
aortic valve implantation, TAVI) v centru z velikim številom posegov.
Rezultati: 33 bolnikov z bikuspidno aortno zaklopko (55–87 let) smo zdravili z metodo transkatetr-
ske zamenjave aortne zaklopke. Srednji logistični EuroSCORE (angl. European System for Cardiac 
Operative Risk Evaluation) je bil 23,2 ± 19,3. Večini pacientov smo vstavili zaklopko Edwards Sapien® 
s transapikalnim pristopom (87,9 %). 9 bolnikom (27,3 %) smo morali dodatno balonsko razširiti 
zaklopko zaradi zmerne do hude paravalvularne regurgitacije, 3 bolnikom (9 %) smo morali vstaviti 
drugo zaklopko zaradi vztrajajoče hude paravalvularne regurgitacije, 2 bolnika (6 %) pa smo morali 
nato še klasično operirati s pristopom preko mediane sternotomije. Po posegu je bila blaga aortna 
regurgitacija prisotna pri 12 bolnikih (36,4%), zmerna AR pri 3 %, regurgitacije večje kot stopnja 2, 
pa nismo zabeležili. Uspešnost delovanja aortne zaklopke po perkutani metodi smo glede na merilo 
VARC (angl. Valve Academic Research Consortium) ocenili na 82 %. Med bolniki z in bolniki brez 
paravalvularne regurgitacije po posegu ni bilo pomembnih razlik v anatomiji BAV, razporeditvi kal-
cija in velikosti ter tipu vgrajene umetne zaklopke. 30-dnevno preživetje je bilo 100 %, 2-letno pa 
70 % (CI: 52.7–93.1), kar je podobno pri bolnikih s paravalvularno regurgitacijo po posegu ali brez 
nje.
Zaključki: Transkatetrska zamenjava aortne zaklopke je izvedljiva pri bolnikih s stenozo bikuspidne 
aortne zaklopke. Tudi v izkušenih centrih je tehnično zahteven poseg povezan z večjim številom do-
datnih balonskih dilatacij, vstavitvijo dodatne druge zaklopke ali potrebo po klasični kardiokirurški 
operaciji. Zanimivo bo videti, ali bodo rezultati podobni tudi pri novejši drugi generaciji perkutanih 
aortnih zaklopk.
Abstract
Background: We report our experience with transcatheter aortic valve implantation (TAVI) in pa-
tients with bicuspid aortic valve (BAV) stenosis.
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Transcatheter aortic valve implantation for bicuspid aortic valve stenosis 9
iZVirni ZnAnSTVeni čLAneK
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Prispelo: 3. 9. 2016 
Sprejeto: 26. 12. 2016
Methods: Perioperative and intermediate-term follow-up data were retrospectively analysed. All 
procedures were performed within the premises of an experienced high-volume TAVI centre.
Results: Thirty-three consecutive BAV patients (age 55 to 87 years) underwent TAVI. Mean logistic 
European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 23,2 ± 19,3. Transapi-
cal Edwards Sapien® valve was implanted in the majority of patients (87.9 %). Nine patients (27.3 %) 
required post-ballooning of the implanted valve for moderate to severe paravalvular leak, 3 patients 
(9 %) required a second valve implantation for persistent severe paravalvular leak, and 2 (6 %) re-
quired conversion to conventional surgery. Post-operative mild aortic regurgitation (AR) was pre-
sented in 12 patients (36.4%) and AR = 2 in 3 %. No AR > 2 was observed. The device success rate ac-
cording to the valve academic research consortium (VARC) criteria was 82 %. Similar BAV anatomy, 
calcium distribution, type and size of implanted valve were noticed in patients with and without 
residual AR. There was no thirty-day mortality. Two-year estimated survival was 70 % (CI: 52.7–93.1) 
and was similar in patients with and without post-procedural residual paravalvular leak.
Conclusions: TAVI in BAV stenosis is feasible but, even in experienced centres, is technically more 
challenging and is associated with a higher rate of post-dilatation, re-valving, and conversion to 
conventional surgery. Results should be re-tested in light of the recent introduction of second-gen-
eration TAVI prostheses.
1. Introduction
Bicuspid aortic valve (BAV) has been 
considered a relative contraindication 
for transcatheter aortic valve implanta-
tion (TAVI) mainly because of the theo-
retical risk for uneven and incomplete 
prosthesis expansion and wall apposi-
tion, resulting from calcium asymmetric 
distribution in the annulus, commis-
sures, and aortic valve leaflets, which will 
eventually lead to consequent increased 
rate of prosthesis malfunction and para-
valvular regurgitation.
Although there are reports describing 
the feasibility of TAVI in patients with 
BAV, experience remains restricted, of-
ten referred to multicentre cohorts, and 
with limited mid-term follow-up infor-
mation (1-8). We present our experience 
focusing on preoperative BAV anatomi-
cal data, perioperative findings, and in-
termediate-term clinical results.
2. Methods
Perioperative and intermediate-term 
follow-up data of all patients with BAV 
treated consecutively with TAVI from 
May 2008 to April 2014 at the Deutsches 
Herzzentrum Berlin, Berlin, Germany, 
were retrospectively analysed. Type of 
BAV, annular geometry, calcium distri-
bution, and calcium amount were all re-
corded. All patients had signed consent 
to the procedure and to the processing 
of their data for medical and scientific 
purposes.
2.1 BAV Classification
Aortic valves were classified as bi-
cuspid according to preoperative multi-
slice computed tomography and trans-
oesophageal echocardiography and were 
arranged in 3 groups (9). Fusion of two 
of the three aortic leaflets was observed 
in all patients. If the fusion occurred 
between the right and the left coronary 
cusps, the BAV was classified as type 1. 
Similarly, type 2 BAV included fusion 
of the right- and non-coronary leaflets, 
whereas fusion of the left- and non-cor-
onary cusps was classified as type 3 BAV. 
Moreover, the presence or absence of a 
raphe was marked with a “+” or a “-“ , re-
spectively (placed next to the valve type).
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Figure 1: Percentage 
of different BAV 
morphological types as 
observed in our patient 
group.
2.2 Geometrical Annular Data
Geometrical annular information was 
analysed using multi-slice cardiac com-
puted tomography. Measures included: 
aortic valve (AV) annulus at the insertion 
of the aortic cusps (perimeter derived di-
ameter, major and minor axis), native AV 
area, LVOT, aortic root, sinotubular junc-
tion and ascending aorta maximal diame-
ters. The annular ellipticity index (EI) was 
calculated as the ratio between the semi-
minor and the semi-major aortic annulus 
axis (EI = b/a, where a is semi-major and 
b is semi-minor axis). We also calculated 
linear and numeric eccentricity, as previ-
ously described by our group (10).
2.3. Aortic Unit Calcification
Information about calcification score 
were obtained from multi-slice comput-
ed tomography and expressed as the AV 
and LVOT calcified volumes. Moreover, 
the calcification area and distribution 
on each of the cusps was also evaluated. 
Measurements were performed auto-
matically using the dedicated planning 
workflow from the software 3mensio 
Valves® (Pie Medical Imaging BV, Maas-
tricht, the Netherlands).
2.4 Implantation Technique
Two different prostheses were im-
planted: transapical Edwards SAPIEN® 
valve (Edwards Lifesciences, Inc., Irvine, 
California) and transfemoral Medtronic 
CoreValve® (Medtronic, Inc., Minne-
apolis, Minnesota). All procedures were 
performed under general anaesthesia 
and following previously described and 
established protocols  (11-13). Rules for 
prostheses sizing did not differ from 
those normally applied for TAVI in tri-
cuspid AV stenosis (14).
2.5 Perioperative and 
Follow-up Evaluation
Perioperative results were collected 
and procedural success/complications 
were classified following the Valve Aca-
demic Research Consortium (VARC) 
recommendations. Intraoperative 
trans-oesaphageal and pre-discharge 
trans-thoracic echocardiography were 
performed. Paravalvular and valvular 
regurgitation was calculated and classi-
fied as mild (I), moderate (II), and severe 
(III) according to semiquantitative and 
quantitative parameters (15).
Trans-prosthetic gradients were cal-
culated together with indexed effective 
orifice areas (EOAi) and eventual patient 
prosthesis mismatch (PPM) (16).
Clinical follow-up through outpatient 
visits (one month after discharge) and 
telephone contacts (after rehabilitation 
and one year after the procedure) was 
performed.
2.5 Statistical Analysis
Data are presented as absolute num-
bers, percentages, and mean ± standard 
deviation.
Patients without and with residual 
paravalvular leak ≥ 1 at the end of TAVI 
were compared.
Comparisons were also performed 
with patients that required prosthesis 
re-ballooning, second valve implanta-
Bicuspid Valve Type
LC + RC, raphe +
LC + RC, raphe -
RC + NC, raphe +
RC + NC, raphe -
LC + NC, raphe +
LC + NC, raphe -
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Transcatheter aortic valve implantation for bicuspid aortic valve stenosis 11
iZVirni ZnAnSTVeni čLAneK
tion, and conversion to conventional 
surgery.
Differences between continuous vari-
ables were tested by means of unpaired 
Student t-test, Mann-Withney test, chi-
square and Fischer exact test whenever 
appropriate. Kaplan-Meier survival 
curves were built and the equality of sur-
vival distribution between patients with 
and without paravalvular leak was tested 
(Mantel-Cox, Breslow, Tarone-Ware).
3. Results
3.1 Perioperative
A total of 33 patients (13 females 
and 20 males) were treated. Preopera-
tive patients and AVs data are reported 
in Table 1 and Figures 1–2. Moreover, 
Table 2 summarizes intraoperative data. 
The majority of patients were treated by 
means of transapical Edwards SAPIEN® 
valve. Nine patients (27.3 %) required 
post- ballooning of an implanted valve 
for moderate to severe paravalvular leak 
occurrence. Three patients required 
a second valve implantation (9 %) for 
persistent severe paravalvular leak that 
became mild after re-valving. Two con-
versions (6 %) to conventional surgery 
were necessary. One patient had mal-
positioning of a self-expandable valve 
with structural damage of the prosthesis 
during implantation. The second patient 
experienced annular rupture during im-
plantation of a balloon expandable valve.
Table 3 includes the intraoperative 
echocardiography together with the 
clinical outcome data. At the end of the 
procedure, mild paravalvular leak was 
noticed in 12 patients (36.4 %) and mod-
erate paravalvular leak in one patient 
(3 %). Central AV regurgitation was re-
ported in one patient (3 %). PPM was 
moderate in 5 patients (15 %) and no pa-
tient developed severe PPM. The device 
Table 1: Patients Baseline Data.
BAV (n = 33)
Age (yrs) 73.0 ± 7.3
Men 20 (60.6 %)
Body surface area (m2) 1.97 ± 0.24
Aortic annulus size (mm) 24.99 ± 3.01
Aortic valve area (cm2) 0.50 ± 0.11
ellipticity index 0.84 ± 0.10
Linear eccentricity 7.04 ± 2.71
numeric eccentricity 0.51 ± 0.18
Max. diameter (mm)
LVoT 40.47 ± 7.02
aortic root 36.64 ± 3.93
sinotubular junction 32.12 ± 4.36
ascending aorta 38.48 ± 5.78
Bicuspid valve type
Lc + rc, raphe + 20 (60.6 %)
Lc + rc, raphe - 4 (12.1 %)
rc + nc, raphe + 7 (21.2 %)
rc + nc, raphe - 2 (6.1 %)
Lc + nc, raphe + 0
Lc + nc, raphe - 0
Calcium score (mm3)
total 5716.34 ± 4989.95
LVoT 1636.94 ± 2275.24
valve 4061.22 ± 3027.96
non-coronary leaflet 1303.30 ± 1026.77
right-coronary leaflet 1446.72 ± 1077.01
left-coronary leaflet 1311.18 ± 1081.87
calcium mass total (g) 8.87 ± 7.71
Logistic euroScore 23.2 ± 19.3
euroScore ii 10.3 ± 11.6
STS score 8.0 ± 9.2
LVeF 48.61 ± 15.33
Data presented as n (%) or mean ± standard deviation. LVOT, left ventricular 
outflow tract; LC, left-coronary; RC, right-coronary; NC, non-coronary; 
EuroSCORE, European System for Cardiac Operative Risk Evaluation; STS, 
Society of Thoracic Surgeons; LVEF, left ventricular ejection fraction.
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
12 Zdrav Vestn | januar – februar 2017 | Letnik 86
Srce in ožiLje
success rate according to VARC criteria 
was 82 %.
No patient died in the first 30 days 
after the procedure. Two patients (6 %) 
died in a different institution because of 
pneumonia and sepsis during the post-
surgical rehabilitation, both 6 weeks af-
ter discharge.
When comparing anatomical vari-
ables of patients without and with ≥ 1 re-
sidual paravalvular leak at the end of the 
procedure, there was a trend for larger 
aortic annular diameter and valve area 
in patients that developed paravalvu-
lar leak (Table 4). Moreover, a trend for 
higher valve calcium volume with higher 
distribution in the right and left coro-
nary leaflets was noticed in patients that 
developed paravalvular leak. Operative 
time was significantly longer in patients 
that developed paravalvular leak. Pros-
thesis performance, in terms of trans-
valvular gradient, effective orifice area 
and eventual PPM, was similar in both 
groups (Table 4).
Moreover, a sub-analysis of patients 
that required re-ballooning (9 patients), 
re-valving  (3 patients), and conversion 
to conventional surgery  (2 patients) 
was performed. Although there were no 
significant differences in terms of valve 
anatomy, ellipticity, calcium distribution, 
and calcium content, these patients had 
significantly larger native annular area, 
perimeter, and perimeter derived diam-
eter when compared to the remaining 
patients (27.6 ± 2.1 mm vs. 24.8 ± 3.0 mm; 
p = 0.01).
3.2 Follow-up
Clinical follow-up was complete in 
all patients and average duration was 
20 ± 15 months (1–70 months). Overall 
two-year estimated survival was 70 % 
(CI: 52.7–93.1) (Figure 3). There were no 
reported cardiac deaths. No patient re-
0
1000
2000
3000
4000
5000
6000
total LVOT valve
no
n-
co
ro
na
ry 
lea
fle
t
lef
t-c
or
on
ar
y 
lea
fle
t
rig
ht
-co
ro
na
ry 
lea
fle
t
Calcium Score
Follow-up Months
0,2
0,4
0,6
0,8
1
2412 36 48 60 72
33, 31, 27, 23, 20, 17,   11   N. at risk
Figure 2: respective calcium scores for different parts of the aortic valve 
apparatus as observed in our patient group.
Figure 3: K-M survival curve in patients undergoing TAVi for bicuspid aortic 
valve stenosis. estimated survivals: at 6 months 90.1% (ci: 80.0-100.0); at 1 
year 82.0% (ci: 68.5-97.8); at 2 years 70.0% (ci: 52.7-93.1).
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Transcatheter aortic valve implantation for bicuspid aortic valve stenosis 13
iZVirni ZnAnSTVeni čLAneK
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
quired reoperation for AV dysfunction 
and/or degeneration or any sort of ad-
ditional cardiac surgery. No significant 
difference (p = 0.5) in terms of estimated 
survival was noticed between patients 
without (66.2 %; CI: 42.4–100.0) and 
with (68.6 %; CI: 45.0–100.0) residual 
paravalvular leak ≥ 1 after TAVI.
Discussion
The occurrence of BAV in patients 
with severe AV stenosis may represent 
a theoretical challenge for TAVI. In fact, 
this anatomic variation that is present 
in at least 50 % of patients submitted to 
conventional AV replacement  (17) has 
been considered, per se, an exclusion cri-
terion for TAVI (18).
In patients with BAV, a potential risk 
of TAVI is mainly in an uneven expan-
sion of the prosthesis, resulting from the 
heterogeneous pliability of the native 
valve and the particular stiffness of the 
leaflet where a raphe is present.
Zegdi et al.  (19) have proven these 
important theoretical drawbacks of 
TAVI in a group of 16 BAV patients 
where a self-expandable stent, specifi-
cally designed for stented valves, was de-
ployed intraoperatively inside the aortic 
valve before undergoing AV resection 
for conventional surgical aortic valve 
replacement. Elliptic stent deployment 
and under-deployment were the rule 
in BAV. In a second phase, the authors 
performed an ex vivo study of a “home-
made” stented valve to confirm that the 
regularity of the coaptation line was de-
pendent on the quality of stent deploy-
ment (20).
Zegdi report, although of seminal im-
portance, presents some differences from 
the daily TAVI practice. First, it does not 
include a phase of balloon valvuloplasty 
before stent deployment within the na-
tive AV annulus. Secondly, it is focused 
on the anatomical adaptation of a self-
expandable stent and does not take into 
consideration the dynamics of balloon 
expandable stents. Finally, it considers 
the ex vivo behavior of a “homemade” 
stented AV prosthesis that may differ 
greatly from the in vivo performance of 
the TAVI prostheses currently available 
on the market.
Table 2: Procedural Data.
Variable BAV (n = 33)
Valve type
edwards 29 (87.9 %)
coreValve 4 (12.1 %)
Access
Edwards
Transfemoral 0
Transapical 29 (100 %)
Transaxillary 0
Transaortic 0
CoreValve
Transfemoral 3 (75 %)
Transapical 0
Transaxillary 1 (25 %)
Transaortic 0
Valve size (mm)
Edwards
23 5 (17.2 %)
26 9 (31 %)
29 15 (51.7 %)
CoreValve
23 1 (25 %)
26 1 (25 %)
29 2 (50 %)
Procedure duration (min) 97.89 ± 36.40
Amount of contrast dye used 
(mL)
133.81 ± 73.27
Data presented as n (%) or mean ± standard 
deviation.
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In fact, despite the described impor-
tant theoretical drawbacks, TAVI has 
been applied, although in limited num-
bers, in BAV patients at prohibitive risk 
for conventional surgery. Published ex-
periences have mainly described acute 
and mid-term results with both balloon 
expandable and self-expandable TAVI 
prostheses. In these patients, occurrence 
of more than moderate aortic regurgi-
tation ranges from 0 to 32 % with mean 
trans-valve pressure gradients always 
below 15 mmHg (1-8).
Mylotte et al. have reported the mul-
ticenter results of TAVI in BAV. In a to-
tal of 139 patients procedural mortality 
was 3.6 %, with valve embolization in 
2.2 % and conversion to surgery in 2.2 %. 
Post-implantation aortic regurgitation 
grade ≥ 2 occurred in 28.4 % but was 
prevalent in only 17.4 % when CT-based 
TAVI sizing was performed. One-year 
mortality was 17.5 % (7).
Bauer et al. evaluated 38 patients with 
BAV within the German TAVI registry, 
and have compared them with a cohort 
group of 1357 tricuspid aortic valve pa-
tients. Although TAVI outcomes were 
satisfactory in both groups, the occur-
rence of ≥ grade 2 AR was significantly 
more common in BAV (25 % vs. 15 %). 
Thirty-day mortality rate was similar 
in both cohorts and BAV was not as-
sociated with higher 1-year mortality 
rate (6). In a case-match study, Kochman 
et al. compared 28 BAV with 84 tricus-
pid valve patients (1:3 ratio), implanted 
with both balloon expandable and self-
expandable prostheses. There was a sta-
tistically insignificant trend for higher 
post-procedural mean pressure gradient 
(11.5 ± 6.4 vs. 10.4 ± 4.5 mm Hg) and aor-
tic regurgitation grade ≥ 2 (32 % vs. 23 %) 
in the BAV patients that did not result in 
an increased 30-day and 1-year all-cause 
mortality (5).
More recently Costopoulos et al. have 
shown more concerning results in a mul-
ticenter experience. When comparing 
TAVI in 21 BAV versus 447 tricuspid AV 
patients, the authors noticed a trend to-
ward a lower device success rate (85.7 % 
vs. 94.4 %) and significantly higher 30-
day mortality rate (14.2 % vs. 3.6 %) in 
the BAV group (4).
Finally, in the most recent multi-
center evaluation proposed by Yousef 
et al.  (8), the authors present results in 
108 patients with BAV treated by TAVI 
within the premises of 21 centres. The 
Table 3: Postprocedural Data.
Variable BAV (n = 33)
effective orifice area (cm2) 2.25 ± 0.55
indexed effective orifice area (cm2/m2) 1.13 ± 0.29
Max. aortic valve gradient (mm Hg) 7.95 ± 4.09
Mean aortic valve gradient (mm Hg) 3.99 ± 2.09
Paravalvular Leak
= 1 12 (36.4 %)
= 2 1 (3 %)
> 2 0
30-Day mortality 0
Complications
conversion To conventional Surgery 2 (6 %)
re-Valving 3 (9 %)
Bleeding 3 (9 %) (1 annular rupture and 2 
apical bleeding)
AKin 0 27 (81.8 %)
AKin 1 2 (6 %)
AKin 2 0
AKin 3 1 (3 %)
TiA 1 (3 %)
Stroke 0
Myocardial infarction 0
Pacemaker implantation 1 (3 %)
Data presented as n (%) or mean ± standard deviation. AKIN, acute kidney 
injury; TIA, transient ischemic attack.
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Transcatheter aortic valve implantation for bicuspid aortic valve stenosis 15
iZVirni ZnAnSTVeni čLAneK
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Table 4: comparison of patients with Ar versus patients without Ar after TAVi.
Characteristic BAV with AR ≥ 1 
(n = 12)
BAV without AR 
(n = 21)
p Value
Age (yrs) 70.5 ± 8.32 74.38 ± 5.96 0.1
Gender
male 10 (83.3 %) 10 (47.6 %) 0.04*
Body surface area (m2) 1.97 ± 0.24 1.97 ± 0.25 0.9
Aortic annulus size (mm) 26.34 ± 2.38 24.28 ± 3.07 0.07
Aortic valve area (cm2) 0.55 ± 0.09 0.47 ± 0.11 0.07
ellipticity index 0.82 ± 0.09 0.84 ± 0.11 0.6
Linear eccentricity 7.92 ± 2.2 6.53 ± 2.94 0.3
numeric eccentricity 0.55 ± 0.13 0.49 ± 0.2 0.6
Max. diameter (mm)
LVoT 39.94 ± 6.72 40.77 ± 6.99 0.8
aortic root 37.38 ± 3.48 36.22 ± 4.01 0.4
sinotubular junction 32.76 ± 4.66 31.76 ± 4.03 0.8
ascending aorta 37.71 ± 4.82 38.91 ± 6.09 0.5
Bicuspid valve type
Lc + rc, raphe + 8 (66.7 %) 12 (57.1 %) nS
Lc + rc, raphe - 2 (16.7 %) 2 (9.5 %) nS
rc + nc, raphe + 1 (8.3 %) 6 (28.6 %) nS
rc + nc, raphe - 1 (8.3 %) 1 (4.8 %) nS
Valve type
edwards 10 (83.3 %) 19 (90.5 %) nS
coreValve 2 (16.7 %) 2 (9.5 %) nS
Calcium score (mm3)
total 5571.83 ± 3313.14 5798.92 ± 5625.93 0.5
LVoT 1289.29 ± 1229.66 1835.60 ± 2629.79 0.6
valve 4232.53 ± 2349.76 3963.33 ± 3284.77 0.6
non-coronary leaflet 1121.73 ± 750.40 1407.06 ± 1120.32 0.8
right-coronary leaflet 1587.04 ± 953.81 1366.54 ± 1109.05 0.7
left-coronary leaflet 1523.71 ± 840.33 1189.73 ± 1157.35 0.2
calcium mass total (g) 8.73 ± 5.06 8.96 ± 8.72 0.5
Procedure duration (min) 124.22 ± 37.75 86.05 ± 26.03 0.01*
Amount of contrast dye used (mL) 141.42 ± 40.83 131.43 ± 83.75 0.08
effective orifice area (cm2) 2.48 ± 0.54 2.17 ± 0.51 0.3
16 Zdrav Vestn | januar – februar 2017 | Letnik 86
Srce in ožiLje
composite primary outcome, according 
to VARC criteria, occurred in one quar-
ter of patients (26.9 %) and was mainly 
driven by re-intervention for valve mal-
position (9.3 %).
Although the topic TAVI in BAV has 
been already analyzed in details, the 
present manuscript presents the largest 
single center experience with an extend-
ed follow-up. All cases were performed 
within the premises of a facility that has 
had a consistent exposure to TAVI since 
its very early introduction. Our results 
confirm what has been previously shown 
by others and clearly demonstrate that, 
although TAVI for BAV has become a 
standard procedure, challenges should 
be expected, even in most experienced 
centres.
We have recently reported our 5-year 
experience with trans-apical TAVI, in-
cluding over 700 patients. In our global 
experience, conversion to surgical aortic 
valve implantation due to rupture of the 
device landing zone or coronary artery 
obstruction was reported in 1.1 % of the 
cases (6 % in the BAV series), prosthesis 
re-dilatation for more than mild para-
valvular leak in 7.5 % (27 % in the BAV 
series), and re-valving in 2.2 % (9 % in 
the BAV series) (13).
Valve hemodynamics in BAV patients 
were also quite different, when compared 
to those reported in our overall experi-
ence. At the end of the procedure, mild 
regurgitation was present in 19.2 %, and 
moderate regurgitation in 0.8 % of the 
patients included in our overall experi-
ence (13). In our sub-group of BAV pa-
tients, mild and moderate paravalvular 
leaks occurred in a slightly higher rate 
(36 % and 3 % respectively).
Although the presence of residual 
paravalvular leak ≥ 1 did not impact 
upon acute and intermediate-term (2-
year) survival, these findings may be 
biased by the very limited sample size. 
In fact, there is emerging and consistent 
evidence that even the presence of mild 
prosthetic regurgitation after TAVI may 
impact significantly upon long-term 
clinical outcomes (21).
From an inferential standpoint, we 
were not able to identify any specific 
anatomical reason that could have in-
creased the risk of TAVI failure in BAV 
patients. In particular, calcification dis-
tribution and calcification amount did 
not seem to differ significantly in pa-
tients that had residual paravalvular 
leak and/or required further interven-
tion. Furthermore, although “ellipticity” 
was not found to be a predictor of out-
come, the sample size and the contained 
number of valves that were truly elliptic 
should be considered as a major limita-
tion of the present study.
Interestingly, we have noticed a trend 
for larger annular anatomy in patients 
developing mild paravalvular leak. 
Moreover, we have reported significantly 
larger native annuli in patients requiring 
further intervention (re-ballooning, re-
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
Characteristic BAV with AR ≥ 1 
(n = 12)
BAV without AR 
(n = 21)
p Value
indexed effective orifice area (cm2/m2) 1.23 ± 0.39 1.10 ± 0.22 0.6
Max. aortic valve gradient (mm Hg) 8.76 ± 3.60 7.59 ± 4.13 0.4
Mean aortic valve gradient (mm Hg) 4.91 ± 2.70 3.81 ± 1.84 0.3
Data presented as n (%) or mean ± standard deviation. LVOT, left ventricular outflow tract; LC, left-
coronary; RC, right-coronary; NC, non-coronary.
Transcatheter aortic valve implantation for bicuspid aortic valve stenosis 17
iZVirni ZnAnSTVeni čLAneK
Transcatheter aortic 
valve implantation 
for bicuspid aortic 
valve stenosis
valving, and conversion) for persistent 
moderate to severe paravalvular leak.
Finally, some comments should be 
given concerning the risk of inappro-
priate prosthesis expansion with conse-
quent valve malfunction in patients with 
BAV undergoing TAVI.
In this context, some authors have 
described a PPM rate after TAVI for tri-
cuspid AV stenosis ranging from 40 to 
60 % (22,23). In our experience, moder-
ate and severe PPMs occurred respec-
tively in approximately 27 % and 8 % of 
patients undergoing TAVI for severe 
stenosis of a tricuspid AV  (24). In the 
present series of BAV patients moderate 
PPM was present in only 15 % of patients 
and no patient experienced severe PPM.
One should take into account also 
the limitations of our article: this was a 
single-centre retrospective analysis of a 
relatively small cohort of patients whose 
BAV have had different, morphological 
types. Prospective studies are needed 
and cooperation between institutions 
with large numbers would be required to 
enlarge the study population numbers.
In conclusion, although TAVI in BAV 
is feasible, it is associated with an in-
creased rate of implantation failures and 
caution should be advised when treat-
ing these patients, even in the premises 
of very experienced centres. The pres-
ent manuscript presents results achieved 
with balloon expandable and self-ex-
pandable prostheses belonging to an 
earlier generation of devices. Outcomes 
may be different once new generation 
TAVI prostheses, including those that 
are fully retrievable and repositionable, 
are tested consistently in this challeng-
ing aortic anatomical scenario.
Disclosure
Mr. Anze Djordjevic has been a fellow 
funded by the ERASMUS PLACEMENT 
PROGRAMME 2013/14 of the European 
Union.
The authors have no other conflicts of 
interest to declare.
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