Advancing Transcatheter Valve Replacement for Severe Aortic
Regurgitation: Innovations in Devices and Multi-Modality Imaging
Julien Dreyfus, MD, PhD1; David Messika-Zeitoun, MD,
PhD2
1: Cardiology Department, Centre Cardiologique du
Nord, 32-36 rue des moulins gémeaux, 93200 Saint-Denis, France
2: Division of Cardiology, University of Ottawa Heart
Institute, 40 Ruskin Street, Ottawa, Ontario, Canada
Word Count : 912 words
Address for correspondence :
Julien Dreyfus, Department of Cardiology, Centre Cardiologique du Nord,
Saint-Denis, France. Tel: +33149334803, Fax: +33149334143, E-mail:
dreyfusjulien@yahoo.fr
For patients with severe symptomatic aortic regurgitation (AR) who are
deemed at high surgical risk, off-label use of transcatheter aortic
valve replacement (TAVR) is increasingly performed. However, the rate of
complications is high in this subset, including migration, paravalvular
regurgitation, pacemaker implantation, stroke, bleeding, vascular
complication, acute renal failure, surgical conversion and mortality.(1)
In this issue of Echocardiography , Hu et al (ref) present their
findings on 70 patients (56% of males, mean age=74±8 years) with severe
symptomatic AR (all in NYHA functional class III or IV) on native or
bioprosthetic valves who underwent a TAVR using the Vita-Flow valves
(Microport), a novel self-expanding valve (Figure). The population was
divided into two groups: group A consisted of 40 patients with aortic
root dilatation or valve prolapse and no valvular calcifications, while
group B comprised 30 patients with aortic valve degeneration and/or mild
senile calcifications (Agatston score ranging from 0 to 100). All
interventions were performed under general anesthesia, with procedural
guidance provided by both fluoroscopy and real-time three-dimensional
echocardiography. A comprehensive pre-procedural assessment of the
anatomy was conducted using both transesophageal echocardiography (TEE)
and computed tomography (MSCT) and dedicated software. The study focuses
on the utility of echocardiography in the pre-procedural screening,
intra-procedural monitoring, and 30-day post-procedural follow-up, while
also identifying potential predictors for post-procedural complications.
The main results from the study can be summarized as follow:
- Multimodality imaging analysis demonstrated significant concordance
between TEE and MSCT especially in the assessment of the annulus and
aorta dimensions, as well as left and right coronary artery height,
enabling accurate device sizing.
- The procedural success rate was high (96%) and there were no deaths
at 30 days.
- Multiple underlying mechanisms of AR were successfully treated.
- Mild peri-valvular leakage was observed in 16% of cases but no
moderate or greater peri-valvular leakage was reported.
- Incidence of significant complications was low, with 3% experiencing
iliac artery dissection, 4% encountering stroke, and 3% developing
acute renal insufficiency within 30 days post-procedure. No migration
was reported.
- A noteworthy 22% of patients required new pacemaker implantation due
to complete atrioventricular block, with a median implantation time of
6 days with right bundle branch block as the only independent
predictor.
- Procedural success correlated with a positive left ventricular and
atrial remodeling at 30 days (reductions in left atrial and left
ventricular diameters, and improvement of the left ventricular
ejection fraction).
The main limitations of this study include its retrospective
single-center design, small sample size (although relatively large for a
single center), mix of TAVR on native valves and valve-in-valve
procedures, and a short follow-up period.
A significant proportion of patients with surgical indications for
severe AR are not referred, often due to high surgical risk or
comorbidities(2,3). Transcatheter treatment of AR is currently on the
rise but is much more challenging than for aortic stenosis, notably due
to the absence of calcifications.
TAVR is currently mostly performed using prostheses developed for aortic
stenosis. A recent multicenter registry (PANTHEON) including 201
patients treated with commercially available devices (self-expandable
and balloon expendable valves developed for AS) showed that with
improvements in TAVR devices, in experienced centers and in selected
patients, satisfactory outcomes can be achieved in a majority of
patients, but that complications rates remained high (12% of
embolization or migration at 1 month and 10% of moderate or greater
residual leakage), regardless of prosthesis type. Critically, these
complications were associated with high mortality or hospitalization for
heart failure rates at 1 year (approximately 25%). Rates of permanent
pacemaker implantation were also high (approximately 22%), often
associated with device oversizing.(1)
Several devices designed for the management of AR are currently
available or under evaluation. Presently, the JenaValve Trilogy system
(JenaValve Technology) is the only dedicated device to have received
Conformité Européenne (CE) mark approval for the transcatheter treatment
of patients with AR. A recent multicenter registry, comprising 58
consecutive patients from 6 centers across Germany, demonstrated
excellent outcomes with a 98% implantation success rate, the absence of
moderate or severe paravalvular regurgitation, a 30-day mortality rate
of 1.7%, and a 19.6% rate of new permanent pacemaker implantation.(4)
The Jena-Valve ALIGN-AR Pivotal Trial (NCT04415047) included 177
patients with 91% of procedures performed under general anesthesia. The
trial yielded a procedural success rate of 95%, with 3% of patients
necessitating subsequent surgery. Only 0.6% experienced moderate or
severe paravalvular regurgitation, and 30-day mortality rate was 2.2%.
Additionally, 24% of patients received new pacemaker implantation, a
rate that tended to decrease with experience, particularly with refined
strategies for device sizing and positioning.
The J-Valve (JC Medical), specifically designed for the treatment of
patients with AR, is another alternative. A recent study including 27
patients for compassionate use found a procedural success rate of 81%
overall and 100% in the last 15 cases, with no patient having residual
AR of moderate or greater degree at 30 days and a 13% rate of new
pacemaker implantation.(5)
In conclusion, there is a genuine enthusiasm for transcatheter AR
management, driven by both industry innovation and clinical demand.
Dedicated devices seem to perform better than devices commercially used
for aortic stenosis, but pacemaker implantation rate remains high.
Multimodal imaging plays a pivotal role in patient and device selection,
procedural guidance, and follow-up. Although echocardiography seems
accurate, as for aortic stenosis, MSCT will remain the method of choice
for pre-intervention procedural planning. As the landscape rapidly
evolves, refining patient selection, procedural techniques, and
postprocedural care will be paramount to ensuring optimal outcomes in
this challenging patient population.