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Scotti et al. Vessel Plus 2021;5:6 I http://dx.doi.org/10.20517/2574-1209.2020.68 Page 9 of 10

Similar to aortic bioprosthetic valves, TMVRpl devices need an assessment of the rates of structural
degeneration, prosthesis-related endocarditis, and thromboembolic/hemorrhagic events. Studies on long-
term clinical outcomes and trials on optimal antithrombotic therapy will provide these data.

While evidence on the use of TMVR for advanced HF is being published [13,14] , whether TMVRpl may play a
role in this setting has yet to be proved. Complete and more reproducible reductions in MR may allow for
an uptitration of heart failure medical therapies, and this gain could lead to even greater clinical benefits.

Studies on TMVRpl available thus far are promising in terms of feasibility and efficacy, but they report
high rates of peri-procedural complications and all-cause mortality (technical success 91.7%, stroke 2.9%,
[19]
unplanned mitral valve surgery 4%, and 30-day mortality 13.6%) . For this reason, the clinical applicability
of these procedures is limited and finds room when TMVR is contraindicated. These data are influenced by
two critical factors:

(1) The patients enrolled in TMVRpl studies are elderly, have a relevant comorbidity burden and very high
[19]
operative risks, or are considered inoperable (compassionate use) .
(2) A quite selective process limits the anatomical eligibility to TMVRpl and consequently the enrollment
rate; screening failure is reported as up to 70% [23,24] .

The great potential of these procedures and their theoretical applicability will be proved in the coming years
when more scientific data become available.

CONCLUSION
Technical and more so technological advances have forged a vast armamentarium of transcatheter mitral
valve therapies. While some TMVR devices (e.g., MitraClip) have large supporting studies, TMVRpl
devices need more evidence. Clinical investigations, in the form of randomized trials, will define the
specific role and the ideal target population of TMVRpl. At the moment, for patients with severe MR,
a repair-first strategy is the preferable choice, and a replacement technique finds applicability in highly
selected cases. As soon as TMVRpl obtains the necessary confirmations to be considered a complementary
strategy to TMVR, a substantial number of transcatheter options will be available to handle mitral
valve disease. A one-device-for-all paradigm is not realistic; having a complete mitral toolbox will be
fundamental to address all the different pathologies, mechanisms, and patients to allow specific patient-
tailored approaches.

DECLARATIONS
Authors’ contributions
Conceived and designed the study, performed data interpretation, and were involved in all the phases of
the writing process: Scotti A, Galasso M, Margonato A, Godino C

Availability of data and materials
Not applicable.

Financial support and sponsorship
None.

Conflicts of interest
All authors declared that there are no conflicts of interest.