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Structural Heart Disease
Aortic Regurgitation and Left Ventricular Remodeling After
Transcatheter Aortic Valve Implantation
A Serial Cardiac Magnetic Resonance Imaging Study
Constanze Merten, MD; Hans-Wilko Beurich, MD; Dirk Zachow, MD; Ahmad E. Mostafa, MD;
Volker Geist, MD; Ralph Toelg, MD; Gert Richardt, MD; Mohamed Abdel-Wahab, MD
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Background—Aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) has been associated with poor
outcomes, but little is known about how it evolves over time. We evaluated left ventricular (LV) function, remodeling, and
the occurrence and evolution of AR after TAVI by using cardiac MRI.
Methods and Results—Forty-three patients treated with transfemoral TAVI underwent cardiac MRI 1 week and 6 months
after TAVI. LV volumes and function were assessed by using standard cine MRI sequences. Phase-contrast imaging
was performed to quantify the degree of AR. The mean age of the evaluated patients was 80 years, and 65% of patients
were women. At baseline MRI, the median LV ejection fraction was 58.1%, which improved significantly at follow-up
to 63.4% (P<0.0001). A significant reduction of LV end-diastolic volume (149.7±41.4–140.1±43.9 mL; P=0.014) and of
LV mass (156.3±32.8–142.7±39.3 g; P<0.001) was observed. Over time, aortic regurgitant fraction increased slightly but
significantly from 5.2% to 7.8% (P=0.04). Subgroup analysis revealed that significant changes of LV ejection fraction,
volumes, and mass only occurred in patients with no or mild AR at baseline MRI, whereas those parameters remained
unchanged in patients with AR more than or equal to grade II.
Conclusions—By using cardiac MRI in patients with TAVI, a significant improvement of LV function, volume, and mass
can be documented. Mild-to-moderate AR is commonly seen, and AR shows a small increase over time. More-than-mild
AR seems to prevent LV functional and structural recovery after TAVI. (Circ Cardiovasc Interv. 2013;6:00-00.)
Key Words: aortic valve insufficiency ◼ cardiac MRI ◼ TAVI ◼ ventricular function, left
T
ranscatheter aortic valve implantation (TAVI) has recently
emerged as an effective alternative therapy for patients
with severe symptomatic aortic stenosis considered to be at
high or prohibitive surgical risk.1,2 Mild paravalvular aortic
regurgitation (AR) is frequent after TAVI with an incidence
ranging from 40% to 94%3–8 probably because of the presence of the calcified native valve between the prosthesis and
the aortic annulus preventing complete sealing of the paravalvular space. More-than-mild AR occurs in 7% to 19%3–5,8,9
and has been recently associated with an increased early and
late mortality.8,10–12 Little is known about how AR after TAVI
evolves over time. In addition, limited data are available about
the impact of TAVI on left ventricular (LV) volumes, function,
and mass, and whether residual AR influences change in LV
structure and function.
Cine cardiac MRI is the gold standard method for the
assessment of LV function and can be combined with flow
measurements over the aortic valve or prosthesis for the
evaluation of AR.13–16 Compared with the evaluation of AR
by echocardiography, MRI is more sensitive in patients with
paravalvular, eccentric, or multiple jets like those frequently
observed after TAVI.17 We therefore sought to evaluate LV
function, LV remodeling, and the occurrence and evolution
of AR in the early and medium-term follow-up after TAVI by
using serial cardiac MRI.
Methods
Patient Population
Between October 2008 and January 2012, all patients treated with
TAVI at our institution were screened for inclusion into this prospective study (n=170; Figure 1). Indication for TAVI was in concordance
with the recent consensus statement.18 Data collection was approved
by the Institutional Review Board, and all patients signed an informed written consent. Patients with a contraindication to MRI (eg,
pre- or post-TAVI pacemakers or MRI incompatible implants) and
patients with claustrophobia, severe arrhythmias, or unstable clinical conditions were excluded from the study. Ultimately, a total of
55 consecutive patients treated with TAVI with the use of the 2 currently commercially available bioprostheses (Medtronic CoreValve,
Received October 12, 2012; accepted July 17, 2013.
From the Heart Center (C.M., H.-W.B., A.E.M., V.G., R.T., G.R., M.A.-W.), and Radiology Department (D.Z.), Segeberger Kliniken GmbH (Academic
Teaching Hospital of the Universities of Kiel and Hamburg), Bad Segeberg, Germany.
The online-only Data Supplement is available at http://circinterventions.ahajournals.org/lookup/suppl/doi:10.1161/CIRCINTERVENTIONS.
112.000115/-/DC1.
Correspondence to Mohamed Abdel-Wahab, MD, Herzzentrum, Segeberger Kliniken GmbH, Am Kurpark 1, 23795 Bad Segeberg, Germany. E-mail
[email protected]
© 2013 American Heart Association, Inc.
Circ Cardiovasc Interv is available at http://circinterventions.ahajournals.org
1
DOI: 10.1161/CIRCINTERVENTIONS.112.000115
2 Circ Cardiovasc Interv August 2013
WHAT IS KNOWN
• Paravalvular
aortic regurgitation after transcatheter
aortic valve implantation has been associated with
poor outcomes, but little is known about how it
evolves over time, and on its potential impact on left
ventricular remodeling.
• The assessment of aortic regurgitation after transcatheter aortic valve implantation by using echocardiography is complex and challenging.
WHAT THE STUDY ADDS
• By using cardiac MRI, significant positive left venDownloaded from http://circinterventions.ahajournals.org/ by guest on June 12, 2017
tricular remodeling occurs within 6 months after
transcatheter aortic valve implantation.
• Aortic regurgitation quantified by MRI does not
­decrease over time.
• In patients with more-than-mild AR, no positive left
ventricular remodeling is observed.
Medtronic Inc, Minneapolis, MN and Edwards SAPIEN XT, Edwards
Lifesciences, Irvine, CA) were included. Of these 55 patients, 43 patients with TAVI were included in the final analysis. The remaining 12
patients underwent baseline MRI examinations, but follow-up MRI
scans could not be performed because of the following: death during
the follow-up period (n=1), pacemaker implantation during the follow-up period (n=1), refusal of follow-up MRI (n=6), aborted followup MRI attributable to claustrophobia (n=2), and loss to follow-up
(n=2; Figure 1). All patients who refused to undergo follow-up MRI
were in good clinical condition and therefore refused the follow-up
in-hospital visit or specifically the MRI examination. All patients
who underwent only a baseline MRI study had grade 0 or I AR (Table
in the online-only Data Supplement).
TAVI Protocol
After informed consent, TAVI with either device was performed via
the transfemoral route. Description of both valves together with review of the implantation technique has been described elsewhere.3,19
Clinical and anatomic selection criteria and device size selection were
in line with previously published recommendations.3,19 Selection of
the prosthetic valve size was based on the measurements of the diameter of the aortic valve annulus obtained by transesophageal echocardiography. At the end of the TAVI procedure, a 5F pigtail catheter was
placed in the upper part of the implanted valve above the leaflets in the
ascending aorta, and an aortography in 30° right anterior oblique and
50° left anterior oblique projections was performed by using 35 mL of
contrast at a flow rate of 16 mL/s. Qualitative assessment of the severity of AR was performed by visual estimation of the concentration of
contrast medium in the left ventricle, with the method of Sellers et
al20 by 2 independent interventional cardiologists. Baseline clinical,
echocardiographic, and procedural characteristics were prospectively recorded for all enrolled patients and entered into an institutional
database. Thirty-day and 6-month clinical assessment together with
transthoracic echocardiography (TTE) and laboratory evaluation were
performed for all patients.
MRI Protocol
The baseline MRI scan was performed 1 to 2 weeks after TAVI, the
follow-up MRI 6 months later. Cardiac MRI was performed by using
a clinical 1.5 Tesla whole-body scanner (Magnetom Espree, Siemens
AG, Erlangen, Germany). All patients were investigated by ECG-gated
cardiac MRI in the supine position with a 5-element cardiac phasedarray coil. The stent carrying the Medtronic CoreValve prosthesis is
made up of nitinol, which is not ferromagnetic and can therefore be
safely examined by MRI (Figure 2). The stent frame of Edwards valve
is composed of cobalt chrome material; nonclinical testing revealed
that it can be safely scanned under routine MRI conditions.
LV volumes and function were determined by cine images using a
standard steady-state free precession sequence in continuous shortaxis planes covering the whole left ventricle from base to apex. For
flow measurements, a breath-hold velocity-encoded phase-contrast
MR sequence was used (through plane, segmented fast low-angle
shot 2-dimensional sequence, repetition time/echo time 46/2.7 ms,
velocity encoding 150–300 cm·s−1, scan in expiration, scan duration
≈10 s). The slice was positioned perpendicular to the long axis of the
ascending aorta closely beneath the upper margin of the stent holding
the CoreValve prosthesis or at the corresponding distance from the
aortic annulus for the Edwards valve, respectively. This position was
chosen because it had proved to be less susceptible to artifacts caused
by the valves and stent compared with a lower position, and a perpendicular cut through the ascending aorta could be achieved more accurately. In fact, no visible artifacts of valves and stents were present on
the analyzed images. Contrast administration was not necessary for
both cine imaging and flow measurements. Consequently, no patients
were excluded because of impaired renal function.
Figure 1. Study population. A detailed description of the study population as part of the overall
transcatheter aortic valve implantation (TAVI) cohort
treated during the study period. ICU indicates intensive care unit; PM, pacemaker; and SAVR, surgical
aortic valve replacement.
Merten et al MRI After TAVI 3
RF was calculated (Figure 3). An RF of ≤15% was graded I (mild),
16% to 30% was graded II (moderate), 31% to 50% was graded III
(moderate to severe), and >50% was graded IV (severe) AR according to the standard grading criteria.13,21 A calculated RF<1% was classified as no AR (grade 0).
Natriuretic Peptides Assay
Blood samples were drawn preprocedurally, at baseline MRI and
the MRI follow-up visit. N-terminal pro-brain natriuretic peptide
(NT-proBNP) was analyzed by using a commercially available kit
(The Elecsys proBNP, Roche Diagnostics, Mannheim, Germany).
Statistical Analysis
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Figure 2. Medtronic CoreValve prosthesis visualized with cardiac
MRI. The Medtronic CoreValve prosthesis visualized in a 3-chamber view with a flow artifact caused by the jet of aortic regurgitation (arrow).
MRI Analysis
MRI data were analyzed by 2 independent and experienced observers.
No formal blinding was performed, but observers had no access to the
results of the baseline scan at the moment of evaluation of followup MRI. Global LV function was assessed by manually contouring
the endocardial borders of end-diastolic and end-systolic images. For
the computation of LV mass, the epicardial borders were additionally
contoured at end diastole. LV volumes, mass, and ejection fraction
were then automatically calculated by the software (Argus WIP 2.3,
Siemens AG, Erlangen, Germany). An LV ejection fraction (LVEF)
>55% was considered normal.
For the assessment of the aortic regurgitant fraction (RF), the
cross-sectional area of the ascending aorta was defined and manually
corrected for motion artifacts that occurred during the breath-hold
scan. By using the standard software (see above), the forward and reverse volumes within this region of interest were determined, and the
For statistical analysis, MedCalc version 10.3.0 (MedCalc Software,
Mariakerke, Belgium) was used. Descriptive results are expressed as
numbers and percentages, and continuous variables are expressed as
mean±SD or median and range. For comparison of initial and follow-up MRI parameters, paired Student t test or Wilcoxon signedrank test was used, based on the distribution of the change in value.
Additionally, Pearson correlation coefficients were calculated to evaluate the relation of LV parameters and aortic regurgitation. A P value
<0.05 was deemed significant.
Results
Baseline Characteristics
Overall patient characteristics are summarized in Table 1. The
mean age of the study patients was 79.9±5.5 years, and 65%
of patients were women. Baseline New York Heart Association (NYHA) functional class was IV in 5 patients and III in 33
patients, and 5 patients had NYHA class II symptoms at baseline. The median logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 17% (range, 7%–82%).
Thirty-five patients had a concomitant diagnosis of coronary
artery disease; in 13 patients, a percutaneous coronary intervention was performed within 1 week before TAVI. Thirty-two
patients (74%) were treated with the Medtronic CoreValve prosthesis, and 11 patients received the Edwards Sapien XT valve.
Figure 3. Flow measurements. For flow measurements, the region of interest was placed along the vessel wall of the ascending aorta.
Flow curves of a patient with no aortic regurgitation (upper curve) and moderate aortic regurgitation (lower curve) are shown.
4 Circ Cardiovasc Interv August 2013
Table 1. Baseline Patient Characteristics Before TAVI
Age, y
79.9±5.5
Females (%)
28/43 (65)
Diabetes mellitus (%)
11/43 (26)
Hypertension (%)
37/43 (86)
Hyperlipidemia (%)
28/43 (65)
Obesity (%)
6/43 (14)
BMI, kg/m
26.0 (17.3–57.2)
2
Logistic EuroSCORE (%)
NT-proBNP, pg/mL
16.6 (7.8–82.0)
2842 (201–49 344)
NYHA class II (%)
5/43 (12)
NYHA class III (%)
33/43 (77)
NYHA class IV (%)
5/43 (12)
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Coronary artery disease (%)
35/43 (81)
PCI during admission (%)
13/43 (30)
Previous PCI (%)
16/43 (37)
Previous CABG (%)
9/43 (21)
Previous myocardial infarction (%)
8/43 (19)
Data presented as mean±SD, median and range, or number and percentage.
Obesity defined as BMI>30 kg/m2. BMI indicates body mass index; CABG,
coronary artery bypass graft; EuroSCORE, European System for Cardiac
Operative Risk Evaluation; NT-proBNP, N-terminal pro-brain natriuretic peptide;
NYHA, New York Heart Association; PCI, percutaneous coronary intervention;
and TAVI, transcatheter aortic valve implantation.
Prosthetic Valve Function After TAVI
The mean transvalvular pressure gradient decreased from
48.2±16.7 mm Hg before intervention to 9.1±4.7 mm Hg
after TAVI (P<0.0001). Angiographic assessment of AR was
performed immediately after the procedure. No AR was seen
in 13 (30%) of the 43 patients. AR was mild (grade I) in 24
patients (56%), whereas in 6 patients (14%), a moderate AR
(grade II) was observed.
Baseline MRI
Baseline MRI was performed at a median of 11 days after
TAVI. At baseline examination, any AR (RF>1%) was present in 37 of the 43 patients (86%); in 6 patients (14%), no
AR was observed. While mild AR was present in 29 patients
(68%), moderate AR was observed in 7 patients (16%) and,
in 1 patient (2%), moderate-to-severe AR was detected. The
median RF of the entire cohort was 5.18% (range, 0.11%–
38.9%). The mean heart rate during flow measurements was
64.1±11.3 bpm.
Baseline MRI showed a median LVEF of 58.1% (range,
22.1%–71.6%). A normal ejection fraction was seen in 23
patients, and another 10 patients had only slightly reduced
systolic LV function with an LVEF of 50% to 55%; in 10
patients, the LVEF was more severely impaired. The mean
end-diastolic volume (EDV) was 149.7±41.4 mL, the
median end-systolic volume was 63.4 mL (range, 22.8–
203.0 mL). Early after TAVI, the mean myocardial mass
was 156.3±32.8 g.
Follow-up MRI
Follow-up MRI was performed at a median of 6 months after
TAVI (range, 5–12 months). AR of any grade was present in
39 of the 43 patients (91%). We observed grade I AR in 31
patients (72%), grade II AR in 5 patients (12%), and grade
III AR in 3 patients (7%; Figure 4). Over time, the mediancalculated aortic RF increased slightly but significantly from
5.2% to 7.8% (P=0.04; Table 2; Figure 4). The mean heart
rate during flow measurement at follow-up did not differ from
baseline MRI (64.1±11.3 versus 64.0±11.7 bpm; P=0.94).
On the contrary, we observed a significant increase of
the median LVEF at follow-up MRI (58.1% versus 63.4%;
P<0.0001). There was also a significant decrease of the EDV
(149.7±41.4 versus 140.1±43.9 mL; P=0.014) and of the LV
myocardial mass (156.3±32.8 versus 142.7±39.3 g; P<0.001;
Table 2; Figure 5). The increase of LVEF was not affected by preTAVI revascularization with percutaneous coronary intervention.
Impact of AR on LV Recovery
No significant correlation was observed between RF and
LV ejection fraction at baseline MRI (P=0.28), whereas a
modest, but significant, correlation was seen between RF
and LVEF at follow-up MRI (r=−0.37; P=0.017). There
was no significant correlation between the RF at baseline
and changes in LVEF (r=−0.18; P=0.24), but we observed
a strong trend toward a correlation between baseline RF
and changes in LV mass (r=0.30; P=0.053), and a significant correlation between RF at baseline and changes in EDV
(r=0.40; P=0.008; Figure I in the online-only Data Supplement). Subgroup analysis revealed that significant changes
of LVEF, EDV, and LV mass only occurred in patients with
Figure 4. Aortic regurgitation at baseline and follow-up MRI. Bar diagrams showing the number of
patients with different grades of aortic regurgitation
(AR) at baseline and follow-up MRI.
Merten et al MRI After TAVI 5
Table 2. Cardiac MRI and NT-proBNP Measurements Shortly After TAVI and at Follow-up
LV ejection fraction, %
Baseline MRI
Follow-up MRI
Sample Change
P Value
<0.0001
58.1 (22.1 to 71.6)
63.4 (24.0 to 74.2)
4.88 (−6.3 to 18.7)
LV EDV, mL
149.7±41.4
140.1±43.9
−9.6±24.5
0.014
LV mass, g
156.3±32.8
142.7±39.3
−13.6±21.2
<0.001
Aortic RF, %
5.2 (0.1 to 38.9)
7.8 (0.0 to 41.9)
1.3 (−7.8 to 14.7)
0.04
2019 (328 to 23 529)
1336 (132 to 30 764)
−579 (−8373 to 7235)
0.025
NT-proBNP, pg/mL
Data presented as mean±SD or median and range. P value obtained by using either the paired Student t test or the Wilcoxon signed-rank test according to the
distribution of the change in value. EDV indicates end-diastolic volume; LV, left ventricular; NT-proBNP, N-terminal pro-brain natriuretic peptide; RF, regurgitant fraction;
and TAVI, transcatheter aortic valve implantation.
no or mild AR at baseline MRI, whereas those parameters
remained unchanged in patients with AR more than or equal
to grade II (Table 3).
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Plasma Concentrations of NT-proBNP
Preinterventionally, NT-proBNP levels were considerably elevated with a median value of 2842 pg/mL (range, 201–49 344
pg/mL). In the early postinterventional period, we observed a
significant reduction of NT-proBNP levels (2842 versus 2019
pg/mL; P=0.025). During a longer follow-up period, we found
a further decrease of NT-proBNP serum levels compared with
pre-TAVI levels (2842 versus 1336 pg/mL; P=0.0001) as
well as a significant reduction between baseline and followup MRI (2019 versus 1336 pg/mL; P=0.017). Additionally, a
moderate, but significant, correlation between the RF and NTproBNP levels was observed at baseline (r=0.33; P=0.046)
and at follow-up (r=0.32; P=0.045; Figure II in the onlineonly Data Supplement).
Discussion
In recent years, TAVI has emerged as an alternative treatment
to surgical aortic valve replacement for patients with severe
symptomatic aortic stenosis and high or prohibitive surgical
risk. Clinical short- and medium-term outcomes compare
favorably with the outcome of surgical aortic valve replacement.1,2,12 Yet, most published series observed a high incidence
of paravalvular AR after TAVI, which occurs in up to 94% of
patients3–8 and is at least moderate in up to one fifth of them.
The present study is the first to use cardiac MRI for the evaluation of the incidence and evolution of AR after TAVI and its
impact on LV functional and structural recovery.
By using cardiac MRI, we found AR of any grade in 86% of
patients early after TAVI, and moderate or severe AR in 19%,
which is concordant with previous studies. Similar to the surgical experience,22 postprocedural AR after TAVI has been recently
associated with increased short- and intermediate-term mortality.8,12 Nevertheless, the few follow-up data available suggested a
stable course or even a decrease in the incidence and severity of
AR after TAVI.6,10,23 In contrast, we observed a small increase in
the incidence and severity of paravalvular AR at follow-up, with
any grade of AR present in most examined patients.
There are several possible reasons for this discrepancy.
First, in previous studies, patients were examined by using
echocardiography. Compared with TTE, MRI has a lower
intraobserver and interobserver variability in the assessment
of regurgitant volumes and might therefore be more reliable
for serial measurements.24 In addition, we demonstrated in
a previous study that conventional TTE has its limitations
in detecting and quantifying post-TAVI AR compared with
MRI.17 The limitations of TTE have been recently highlighted
in the European Association of Echocardiography/American
Society of Echocardiography recommendations for the use of
Figure 5. Left ventricular (LV) function
and aortic regurgitant fraction at baseline
and follow-up MRI. Dot-and-line diagrams of parameters of LV function and
mass and aortic regurgitant fraction at
baseline and follow-up MRI demonstrating an increase of LV ejection fraction, a
decrease of end-diastolic volumes and
myocardial mass, as well as an increase
of the aortic regurgitant fraction. EDV
indicates end-diastolic volume; EF, ejection fraction; and RF, regurgitant fraction.
6 Circ Cardiovasc Interv August 2013
Table 3. Changes in LV Function and Structure Stratified by
the Degree of Post-TAVI Aortic Regurgitation
Baseline MRI
Follow-up MRI
Sample Change
P Value
AR grade 0 or I (n=35)
LVEF, %
57.0±9.4
62.3±7.9
5.3±5.7
<0.001
EDV, mL
141.2±32.8
128.3±29.0
−12.9±18.8
<0.001
LV mass, g
150.8±31.6
135.0±33.4
−15.8±14.8
<0.001
AR grade ≥ II (n=8)
LVEF, %
43.2±17.0
47.2±16.1
4.0±8.1
0.20
EDV, mL
186.7±55.9
191.7±61.1
4.9±39.8
0.74
LV mass, g
180.4±28.3
176.4±47.4
−4.0±38.8
0.78
Data presented as mean±SD. P value obtained by using the paired Student
t test. AR indicates aortic regurgitation; EDV, end-diastolic volume; EF, ejection
fraction; LV, left ventricular; and TAVI, transcatheter aortic valve implantation.
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echocardiography in transcatheter valve interventions.25 TTE
allows only semiquantitative estimation, and eccentric or multiple jets are possibly underestimated. In contrast, by using
flow measurements by cardiac MRI, a quantitative assessment of AR is possible, which is independent of the number or eccentricity of the regurgitant jets.17 Another possible
explanation for the increasing AR might be a higher compliance of the left ventricle attributable to the dwindling of LV
mass after TAVI. This could also explain why this increase
of AR was not observed after shorter periods of follow-up.
A recently published study using standardized core echocardiography laboratory analysis revealed similar findings with a
small, but significant, increase in AR during a 3-year observation period.26 However, on an individual basis, AR was stable
in most patients with changes of only a few percentage of RF.
Because of the grading of AR according to the absolute RF,
very small changes of RF could nevertheless result in a different AR grade between baseline and follow-up MRI. The
clinical value of these minor however statistically significant
changes remains to be determined.
Previously published data analyzing changes in LV systolic function after TAVI are conflicting. Several studies
found unchanged LVEF during follow-up of up to 1 year after
TAVI,27,28 whereas in others, a highly significant increase of
LVEF was observed.29–33 In all of these studies, LV function
was assessed by echocardiography. We herewith present the
first analysis of temporal changes in LV function after TAVI
by using MRI, which is considered the reference method for
the evaluation of LV function, and we observed a significant
increase of LVEF from 58% at baseline to 63% at followup. We also observed a decrease of LV EDV from baseline
MRI to follow-up. Earlier echocardiography studies equally
revealed inconsistent results on this topic with a reduction of
LV diameters29,30 in some publications, whereas in others, no
significant changes were found.27,28 Interestingly, this reduction of EDV could be observed despite a significant increase
of AR in the entire cohort. This might be attributable to a
statistical rather than a physiological effect because there
was no decrease in EDV in the subgroup of patients with AR
more than or equal to grade II; in the larger group of patients
with AR less than or equal to grade I, however, the decrease
was significant. This is also underscored by the significant
correlation we observed between aortic RF and changes in
EDV between baseline and follow-up MRI and the correlation between RF and NT-proBNP levels, both reflecting an
increased volume overload associated with higher baseline
RF. The lack of significant change in LV volumes in these
patients may signal an important effect on LV structure during the long term; however, larger studies are needed to assess
whether this would negatively impact the changes observed
in LV function.
Finally, our finding of a significant reduction of LV mass is
in line with the results of previous echocardiography studies
that gave homogeneous evidence of LV mass regression after
TAVI.23,27–29 The rapid LV mass regression that is generally
observed after TAVI, and much less after surgical aortic valve
replacement, may be partly explained by the fact that both
TAVI prostheses correspond to stentless surgical valves and
have larger valve areas and lower transvalvular gradients.29
Previous work demonstrated the association of LV fibrosis in
patients with severe aortic stenosis and functional recovery
after surgical aortic valve replacement.34 In the elderly population receiving TAVI, a higher degree of myocardial fibrosis
might be assumed, so that the findings of early improvement of systolic LV function and mass regression are even
more interesting. But again, these positive changes were not
observed in patients with more-than-mild AR.
Study Limitations
There are several limitations to our study. First, we could not
obtain follow-up data for all initially examined patients, and
only 20% of those examined showed more-than-mild AR.
Therefore, the exact influence of significant AR after TAVI on
temporal changes of LV function, volumes, and mass cannot
be determined because the study population was too small for
robust subgroup analyses. Second, because the presence of cardiac devices such as pacemakers is a contraindication for cardiac MRI, all patients with such devices had to be excluded from
the study. This lowered the number of eligible patients because
atrioventricular block or bundle–branch block is a common complication of TAVI. Additionally, only clinically stable patients
participated in this MRI study, so that patients with severe AR or
severely impaired LV function might have been excluded. The
slightly different hemodynamics of the CoreValve prosthesis
compared with the Edwards Sapien XT valve might impact AR
and functional recovery. However, because of the small number of patients receiving the Edwards valve (n=11), no subgroup
analysis was performed to compare both prostheses.
Conclusions
By using cardiac MRI in patients with TAVI, a significant
improvement of LV function, volume, and mass can be documented 6 months after valve implantation. Mild-to-moderate
AR is commonly seen after TAVI, and AR shows a small
increase over time. More-than-mild AR seems to prevent LV
functional and structural recovery after TAVI.
Acknowledgments
We thank Dr Derek R. Robinson (senior lecturer of statistics,
University of Sussex, Brighton, England) for his professional statistical support. We are grateful to Dr Judith Hummerjohann and Kathrin
Merten et al MRI After TAVI 7
Lehmann (Radiology Department, Segeberger Kliniken GmbH)
for their professional support during the performance of this work.
Likewise, we thank the clinical research group at the Heart Center,
Segeberger Kliniken GmbH, especially Susanne Sachse and Daniela
Schuermann-Kuchenbrandt.
Disclosures
Drs Richardt and Abdel-Wahab report receiving a research grant from
Medtronic. The other authors report no conflict.
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Downloaded from http://circinterventions.ahajournals.org/ by guest on June 12, 2017
Aortic Regurgitation and Left Ventricular Remodeling After Transcatheter Aortic Valve
Implantation: A Serial Cardiac Magnetic Resonance Imaging Study
Constanze Merten, Hans-Wilko Beurich, Dirk Zachow, Ahmad E. Mostafa, Volker Geist, Ralph
Toelg, Gert Richardt and Mohamed Abdel-Wahab
Downloaded from http://circinterventions.ahajournals.org/ by guest on June 12, 2017
Circ Cardiovasc Interv. published online August 13, 2013;
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SUPPLEMENTAL MATERIAL
Supplemental table
Baseline demographics and cardiac MRI measurements of the study cohort compared to
patients who only underwent baseline MRI
Age (years)
Females (%)
Logistic EuroSCORE (%)
Study cohort
(n=43)
79.9 ± 5.5
28/43 (65)
16.6 (7.8 – 82.0)
Baseline MRI only
(n=12)
83.7 ± 5.3
8/12 (67)
22.3 (11.4 – 54.4)
p
0.04
0.60
0.12
LV ejection fraction (%)
LV EDV (ml)
LV mass (g)
Aortic RF (%)
58.1 (22.1 – 71.6)
149.7 ± 41.9
156.3 ± 32.8
5.2 (0.1 – 38.9)
53.0 (32.1 – 65.8)
146.4 ± 39.6
133.5 ± 16.7
5.5 (1.0 – 13.3)
0.35
0.80
0.02
0.53
Data presented as mean ± SD, median and range, or number and percent
MRI = magnetic resonance imaging; LV = left ventricular; EDV = enddiastolic volume; RF =
regurgitant fraction
1
Supplemental figures and figure legends
Supplemental figure 1: Correlation between regurgitant fraction at baseline MRI and
changes in enddiastolic volume.
EDV = enddiastolic volume, RF1 = regurgitant fraction at baseline MRI
2
Supplemental figure 2: Correlation between regurgitant fraction and NT-proBNP levels
at baseline and follow-up MRI
RF 1 = regurgitant fraction at baseline MRI; RF 2 = regurgitant fraction at follow-up MRI
3