Transcatheter Mitral Valve Replacement in the Transcatheter Aortic Valve Replacement Era
2019; Wiley; Volume: 8; Issue: 22 Linguagem: Inglês
10.1161/jaha.119.013352
ISSN2047-9980
AutoresLuca Testa, Antonio Popolo Rubbio, Matteo Casenghi, Gaetano Pero, Azeem Latib, Francesco Bedogni,
Tópico(s)Coronary Interventions and Diagnostics
ResumoHomeJournal of the American Heart AssociationVol. 8, No. 22Transcatheter Mitral Valve Replacement in the Transcatheter Aortic Valve Replacement Era Open AccessReview ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citations ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toOpen AccessReview ArticlePDF/EPUBTranscatheter Mitral Valve Replacement in the Transcatheter Aortic Valve Replacement Era Luca Testa, MD, PhD, Antonio Popolo Rubbio, MD, Matteo Casenghi, MD, Gaetano Pero, MD, Azeem Latib, MD and Francesco Bedogni, MD Luca TestaLuca Testa *Correspondence to: Luca Testa, MD, PhD, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy. E‐mail: E-mail Address: [email protected] IRCCS Policlinico San Donato, , Milan, , Italy , Antonio Popolo RubbioAntonio Popolo Rubbio IRCCS Policlinico San Donato, , Milan, , Italy , Matteo CasenghiMatteo Casenghi IRCCS Policlinico San Donato, , Milan, , Italy , Gaetano PeroGaetano Pero IRCCS Policlinico San Donato, , Milan, , Italy , Azeem LatibAzeem Latib Department of Cardiology, , Montefiore Medical Center, , New York, , NY and Francesco BedogniFrancesco Bedogni IRCCS Policlinico San Donato, , Milan, , Italy Originally published7 Nov 2019https://doi.org/10.1161/JAHA.119.013352Journal of the American Heart Association. 2019;8:e013352IntroductionAfter the success and worldwide adoption of transcatheter aortic valve replacement (TAVR), the percutaneous replacement of a diseased mitral valve (MV) rapidly became a target for investigators and industry. The rejuvenated enthusiasm of industry in this field is also corroborated by the fact that, in 2015, ≈2.5 billion dollars were invested in MV technology development and engineering, making this topic extremely timely. However, although transcatheter aortic Valve replacement has already become the standard of care for the treatment of aortic stenosis (AS) in patients considered at increased risk for conventional surgery,1, 2, 3 transcatheter MV replacement (TMVR) has not yet achieved the same results.MV disease is more common than AS,4, 5 and the surgical approach still remains the gold standard treatment for degenerative mitral regurgitation (MR).3 For patients at high surgical risk who are denied surgery and for whom medical therapy is not sufficient,6 TMVR may mature as a promising therapeutic option.7As a matter of fact, MR is the most common valve disease, considering that in developed countries the prevalence of rheumatic heart disease and consequent mitral stenosis encountered a dramatic reduction in the past decades.4 Moreover, the increased life expectancy and the growing incidence of ischemic heart disease, combined with advanced medical and interventional therapies, have led ischemic functional secondary MR and degenerative primary MR to further increase.8 Consequently, this growing interest in the development of percutaneous treatment options for MV disease goes parallel with the much higher prevalence of this valvulopathy in the general population, combined with the increased group of high‐risk elderly patients who could not benefit from the standard surgical treatment.9Insights into the Technical Challenges Between TMVR Versus transcatheter aortic Valve replacementAnatomical and pathophysiological reasons1 traditionally led to a preference for an MV repair rather than a replacement,10, 11 thus contributing to the delay in the evolution of TMVR technology; only a relatively small number of cases of TMVR have been performed worldwide. Various trials studying different devices are still ongoing or in their early stage. TMVR can provide some advantages over percutaneous repair, in virtue of an extended use in difficult or complex MV anatomical features and with a theoretical more predictable result in terms of MR reduction. Nevertheless, different challenges have been influencing the development and growth of TMVR, especially if compared with transcatheter aortic Valve replacement.12, 13, 14All the features and technical challenges of TMVR versus transcatheter aortic Valve replacement are presented as follows, and as listed in Table 1.Table 1. Challenges Between TMVR vs TAVRVariable TMVRTAVRDemographic differencesYounger patientsOlder patientsPathophysiological aspects Nonrheumatic DMR or ischemic FMR Often associated with TR and/or AF Degenerative calcified AS Often isolatedGold standard treatment Surgical mitral valve repair preferred to replacement Percutaneous repair in high‐risk patients SAVR for aortic regurgitation and for bicuspid anatomy TAVR in high‐ or intermediate‐risk patientsDurability of bioprosthetic valvePoor in mitral positionSatisfactory in aortic positionAccess siteMostly transapical or transfemoral with transseptal punctureMostly transfemoralInherent technical risks LVOT obstruction Foreshortening in left atrium Anchoring PVLs Coronary obstruction during/after ViV procedure PVLsClinical studies Early stage of safety and feasibility trials Anecdotal case series Safety and feasibility trials 5‐y results available Assessed in high, intermediate, and low surgical risk patientsAF indicates atrial fibrillation; AS, aortic stenosis; DMR, degenerative mitral regurgitation; FMR, functional mitral regurgitation; LVOT, left ventricle outflow tract; PVL, paravalvular leak; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement; TMVR, transcatheter mitral valve replacement; TR, tricuspid regurgitation; ViV, valve in valve.Demographic VariablesDemographic differences for the age can be encountered between patients with degenerative aortic and MV disease in surgical case series. The age of patients becomes even more important considering that the life expectancy of the treated patients can exceed the long‐term durability of the valve itself. It has been estimated that a surgical bioprosthesis is prone to degenerate within 20 years.15 This observation is really more demanding for patients who undergo surgical MV replacement who are on average 10 years younger than patients who undergo aortic valve replacement.16 Indeed, it is well established that bioprosthetic valves have a higher tendency of structural degeneration in younger patients because of greater hemodynamic stress on the valve, differences in calcium metabolism, prosthesis‐patient mismatch, or immune response.17 As such, a structural bioprosthesis deterioration is more frequent in mitral than aortic valves, as the MV is exposed to higher mechanical stress caused by the systolic pressure gradient, with a consequent impact on durability of mitral bioprosthesis, if compared with aortic ones. Transposing these epidemiological surgical observations to percutaneous treatment allows a better understanding as to how life expectancy is still a critical issue in TMVR development and diffusion rather than in transcatheter aortic Valve replacement.Percutaneous Access Sitetranscatheter aortic Valve replacement is generally easily performed within a transfemoral access, after an accurate computed tomographic scan or angiographic evaluation. In the event that iliofemoral access is not available, also transsubclavian, transcarotid, transaxillary, transaortic, or transapical access can be used. Newer transcatheter aortic Valve replacement devices include smaller delivery sheaths if compared with the first generation and allow the possibility to reposition or recapture the device when in a suboptimal position. For TMVR, in light of the larger dimensions of the valves and delivery system currently used, transfemoral access with transseptal puncture is often demanding, in favor of a more invasive transapical or transatrial one. Indeed, transseptal access inevitably limits the maneuvers in the left atrium and valve positioning, increasing the difficulty of a high‐profile prosthesis to reach an angled mitral annular plane. Consequently, this situation often requires highly curved or steerable guide catheters, with limited possibility to transmit torque to the system. On the contrary, if the transapical access provides an easier way to deploy a mitral device, this technique is impaired by a higher degree of myocardial damage, especially in elderly/frail patients, as the transcatheter aortic Valve replacement experience clearly showed.18, 19Anatomical and Pathophysiological ReasonsAS often occurs as an isolated cardiac condition in patients with preserved left ventricle (LV) ejection fraction or in patients with impaired LV contractility, which may recover once the outflow obstruction is removed. transcatheter aortic Valve replacement allows the deployment of an aortic device in a tubular, rigid, calcified annular structure, providing a stability similar to the surgical intervention.20On the other hand, the MV is a functional apparatus rather than a "valve,"21 and 2 completely different causes (primary or secondary) can be identified with various degrees of coexistence, particularly in elderly people. Alterations of both the valve and the subvalvular structures should be assessed to define the underlying mechanism of the pathological condition (annular dilation, leaflet alterations, chordal rupture, tissue calcifications, and so on) and consequently to decide the most appropriate approach for repair or replacement. Given the variability of anchoring and delivery of available prostheses, a detailed assessment of the MV anatomical features will be required for TMVR.The characteristics of the annulus, in terms of shape, sizing, and calcification, and the dimensions of the LV, which are critical to avoid any impairment of the outflow, should be carefully taken into account.22The mitral annulus is larger than the aortic one and requires larger prostheses and, thus, larger delivery systems. At the same time, it provides less support than the aortic annulus, as a result of not being a complete fibrous ring and the lack of calcification.23 It is well‐known that annular and aortic root calcification load is important in the setting of transcatheter aortic Valve replacement, as it offers an increased grip and better seating of the prosthesis, although it may increase the risk of paravalvular leaks (PVLs) after the implant. Mitral annular calcifications are less common, and their presence may obviously condition the implant of a transcatheter mitral prosthesis too. For this purpose, the role of TMVR in presence of considerable annular calcification is less clear, as shown in the MAC (mitral annular calcification) Global Registry, which studied 116 patients who underwent TMVR with balloon‐expandable aortic prosthesis, in presence of severe mitral annular calcification. This study showed the TMVR in this condition is feasible, but associated with high early and midterm mortality at 1 year, although patients who survived at 1‐year follow‐up present sustained improvement of symptoms.24The mitral annulus can be defined as a junction of left atrium, LV, and mitral leaflets and represents a dynamic structure that can afford some degree of distortion itself as well as that of the surrounding structures; however, when a transcatheter valve is implanted, there is always a risk of migration of the prosthesis because of the phasic systolic contraction.The D‐shape configuration of the mitral annulus represents another major issue, as this asymmetrical conformation does not consent to achieve uniformly radial force, increasing the risk of PVLs or prosthesis migration. On the other hand, the rigid, often symmetrical, elliptical shape of the aortic valve permits a more correct device sizing and consequent sealing in transcatheter aortic Valve replacement. Likewise, the acquired experience and the success of transcatheter aortic Valve replacement have led, over time, to an expanded use of this procedure also in challenging anatomical features, such as bicuspid aortic valves, or different mechanisms of disease, such as aortic regurgitation.25Differently from AS, MR is often coexistent with other valvular disease, such as tricuspid regurgitation, severe pulmonary hypertension, and atrial fibrillation, with significant and independent morbidity and mortality rates.26, 27 Indeed, in patients undergoing MV surgery, a concomitant tricuspid repair is often performed to prevent the recurrence of heart failure symptoms.28 Moreover, atrial fibrillation in these patients tends to be chronic or recurrent because of atrial enlargement, with a low likelihood that sinus rhythm will be reestablished after surgery. In this case, adjunctive antiarrhythmia surgery as well as left atrial appendage excision can be performed.The presence of tricuspid regurgitation and/or atrial fibrillation represents another important issue in the setting of TMVR; indeed, any tricuspid regurgitation is an exclusion criterion for clinical trials studying TMVR, and the results in this setting are therefore not well‐known.Device‐Related and Technical FeaturesBoth the surgical and percutaneous replacement of MV affects the overall performance of the LV, as a consequence of the impairment of the subvalvular structures.29 In the earliest experience, percutaneous heart valves originally designed for the aortic valve, such as the Edwards SAPIEN XT, were generally adapted for TMVR.30 As we learned from transcatheter aortic Valve replacement, calcifications are important to ensure adequate valve anchoring and deployment of an aortic prosthesis,31 especially in the mitral position. As such, this technique is limited as severely calcified leaflets are uncommon in the MV.Differences between surgical aortic and MV replacement are also maintained in the setting of valve‐in‐valve (ViV) procedures. ViV procedures comprise a second valve implanted within the first degenerated valve.32, 33 In case of aortic ViV, one of the main issues is the possible risk of coronary occlusion, whereas for mitral ViV, one of the main issues is the encumbrance caused by the second valve that may interfere with the LV outflow tract (LVOT).34 The foreshortening of the valve in the left atrium may be unpredictable as well. However, the risk of LVOT obstruction remains the most important challenge in TMVR, independently from ViV and especially when nondedicated devices are used. The current reported incidence of LVOT obstruction in TMVR is on average ≈9.3%.1 Potential predictors of LVOT obstruction are the angle of the MV in relation to the LVOT long axis, especially if they are perpendicular or in the presence of small LV cavity, bulging or severe hypertrophy of the basal interventricular septum, long anterior MV leaflets, and dynamic alterations as the pushing of the native anterior leaflet toward the LVOT. Also, prosthesis protrusion and device flaring could be potential risk factors for LVOT occlusion. This device protrusion leads to the creation of a "neo‐LVOT," included among the device, the native anterior mitral leaflet, and the interventricular septum. Understanding individual valve geometry is detrimental to predict a potential feared and fatal condition, such as LVOT obstruction. To avoid this, a computed tomographic scan can predict the new LVOT geometry after a virtual implant, by embedding a cylindrical contour into the computed tomographic data set or the actual valve. Other techniques, such as TMVR septal ablation or laceration of the anterior mitral leaflet, can be used to avoid LVOT obstruction.35, 36, 37, 38PVL represents another important issue to focus on. In the transcatheter aortic Valve replacement experience, the occurrence of PVL has been reduced with the new‐generation prostheses that have skirts in the inflow portion of the frame and are usually recapturable and/or repositionable.39 On the contrary, TMVR can be associated with a higher incidence of PVL because of reduced anatomical support, the asymmetrical shape of the annulus, or asymmetric leaflets. Balloon postdilation of mitral prostheses could be more difficult, considering the proximity to the circumflex artery, the aortic valve, and the conduction system. Future improvement of the design of TMVR should surely address this fundamental point.Finally, MV repair is generally the treatment of choice. Over 60% of patients who are candidates for MV surgery undergo valve repair rather than replacement.11 MV repair is associated with lower mortality and morbidity than replacement, although replacement could offer some advantages by giving a more complete and reproducible reduction in MR. Current guidelines widely emphasize that surgical repair, especially annuloplasty, is the preferred approach over replacement in primary MR.3 This result is mostly driven by the possibility of conserving the subvalvular apparatus, particularly chordal structures, with the purpose of preserving LV function. On the other hand, while considering secondary MR, the most appropriate approach of treatment still remains controversial as the underlying LV dysfunction and the progressive annular dilation can impact outcome, durability, and long‐term results. As such, high‐risk patients with functional secondary MR may become the most likely recipients in which TMVR, if damage to subvalvular structures is avoided, could prove beneficial and successful.TAVR Clinical StudyThe treatment of AS in high‐ or intermediate‐risk patients with transcatheter aortic Valve replacement is nowadays a consolidated therapy. Although initial experience of transcatheter aortic Valve replacement was conditioned by a limited number of early‐generation prostheses, the widespread diffusion of this procedure has led over time to a growing interest to improve existing devices or develop newer ones, resulting in a wide selection being currently available (Figure 1). Comparisons among different transcatheter aortic Valve replacement devices are still limited, and the choice of a specific prosthesis depends on various reasons, such as annulus dimension, distribution of calcium, coronary ostium height, peripheral vasculature, and single operator preferences or center expertise.Download figureDownload PowerPointFigure 1. Current transcatheter aortic valve replacement devices. A, Edwards SAPIEN XT (Edwards Lifesciences Inc). B, Edwards SAPIEN 3 (Edwards Lifesciences Inc). C, CoreValve Evolut R (Medtronic Inc). D, CoreValve Evolut PRO (Medtronic Inc). E, Acurate NEO (Boston, Marlborough). F, Acurate TA (Boston, Marlborough). G, Portico (Abbott). H, Biovalve (Biotronik). I, Centera (Edwards Lifesciences Inc). J, Direct Flow (Direct Flow Medical Inc), not commercially available. K, Lotus (Boston), not commercially available. There was recent US Food and Drug Administration approval for the new Lotus Edge.The current lines of evidence for transcatheter aortic Valve replacement are supported by various clinical trials that evaluated the safety, the efficacy, and the satisfactory hemodynamic results of this procedure.2, 40, 41, 42, 43The results of these studies, which confirmed the noninferiority of transcatheter aortic Valve replacement against conventional surgical therapy, are valid for both balloon‐expandable and self‐expanding valves. Over time, these randomized clinical trials have also been accompanied by experiences coming from different multicenter or single‐center registries that have enriched the wealth of information that we have today on this procedure. The adequate hemodynamic profile of transcatheter aortic Valve replacement at 5‐year follow‐up has been recently reported by the PARTNER‐1 (Placement of Aortic Transcatheter Valves) trial, which confirmed that the occurrence of structural valve deterioration in transcatheter aortic Valve replacement was low.44 In a subanalysis, the PARTNER‐1A trial showed similar valve performance between transcatheter aortic Valve replacement and surgical replacement, although the incidence of PVLs was superior in the transcatheter aortic Valve replacement group.45 Attention to durability of transcatheter aortic Valve replacement is also confirmed by the FRANCE‐2study that reported a low incidence of severe deterioration (2.5%) in transcatheter aortic Valve replacement at 5‐year follow‐up.46 The growing success of transcatheter aortic Valve replacement has led to an expansion of the indication for the procedure to patients at low surgical risk. Two recent clinical trials, such as the PARTNER 3 (NCT02675114) and EVOLUT (NCT02701283) trials, confirmed that transcatheter aortic Valve replacement with the latest‐generation balloon‐expandable SAPIEN 3 and the self‐expanding Corevalve, Evolut R, or Evolut PRO are superior or at least as good, respectively, as surgical replacement in low‐risk patients.47, 48 Given these data, it looks reasonable to expect an extended use of transcatheter aortic Valve replacement in low‐risk patients, with an equal indication for transcatheter aortic Valve replacement and surgery in guidelines. Considering that surgical bioprosthetic valves present a tendency to deterioration arising from 10 to 20 years, only the longest follow‐up on transcatheter aortic Valve replacement series could confirm the real durability of the latest generation of valves used for transcatheter aortic Valve replacement and permit the formulation of real comparisons about durability between transcatheter aortic Valve replacement and surgery, particularly in patients with a long life expectancy.TMVR Devices Under Clinical StudyDifferent transcatheter devices have been designed for the treatment of MR (and, in some cases, for off‐label treatment of mitral stenosis).19 Differently from transcatheter aortic Valve replacement, most of the TMVR technologies are still under clinical investigation or in their early experience in safety and feasibility trials (Table 2). Therefore, information about their durability, structural deterioration, or comparison with surgery is still far. The principal devices on study are presented below (Figure 2).Table 2. TMVR Device Characteristics, Primary Outcomes, and StudiesDevice NameDescriptionPrimary OutcomesStatusCardiAQ‐EVOQUE (Edwards Lifesciences Inc)Nitinol self‐expanding trileaflet valve, composed of bovine pericardial tissueTransapical/transseptalEVOQUE valve: new redesigned version of the valveCompassionate use (n=13)Technical success, 92%Mortality at 30 d, 45%Early Feasibility Study of the CardiAQ TMVI System (Transfemoral and Transapical DS) (NCT02515539M); withdrawnA Clinical Study of the CardiAQ TMVI System (Transapical DS) (NCT02478008); early terminationRELIEF (CardiAQ‐Edwards TMVR Study) (NCT02722551); withdrawnEdwards EVOQUE TMVR Early Feasibility Study (NCT02718001); still recruitingTiara (Neovasc Inc, Canada)Nitinol self‐expanding trileaflet valve of bovine pericardial tissueTransapicalInitial results (n=30)Technical success, 90%Mortality at 30 d, 10%TIARA‐I (Early Feasibility Study of the Neovasc Tiara: Mitral Valve System) (NCT02276547); still recruitingTIARA‐II (Tiara Transcatheter Mitral Valve Replacement Study) (NCT03039855); still recruitingFORTIS (Edwards Lifesciences Inc)Nitinol self‐expanding trileaflet valve of bovine pericardial tissueTransapicalCompassionate use (n=13)Technical success, 76.9%Mortality at 30 d, 38.5%High rate of valve thrombosis; the company put the studies on holdTendyne (Abbott Inc)Self‐expanding trileaflet valve of porcine pericardial tissue, mounted on nitinol double‐frame stentTransapicalInitial results (n=100)Technical success, 96%Mortality at 30 d, 6%Expanded Clinical Study of the Tendyne Mitral Valve System—Global Feasibility Study (NCT02321514); still recruitingSUMMIT (Clinical Trial to Evaluate the Safety and Effectiveness of Using the Tendyne Mitral Valve System for the Treatment of Symptomatic Mitral Regurgitation) (NCT03433274); still recruitingFeasibility Study of the Tendyne Mitral Valve System for Use in Subjects With Mitral Annular Calcification (NCT03539458); still recruitingIntrepid (Medtronic Inc)Nitinol self‐expanding trileaflet valve of bovine pericardial tissueTransapical (transseptal approach under development)Initial results (n=50)Technical success, 96%Mortality at 30 d, 14%APOLLO (Transcatheter Mitral Valve Replacement With the Medtronic Intrepid TMVR System in Patients With Severe Symptomatic Mitral Regurgitation) (NCT03242642); still recruitingCaisson (LivaNova, UK)Nitinol self‐expanding trileaflet valve of porcine pericardial tissue, with a D‐shaped anchorTransseptalStill not knownPRELUDE (Caisson TMVR System Early Feasibility Study) (NCT02768402); active, not recruitingINTERLUDE (Caisson TMVR) (NCT03661398); active, not recruitingHighLife (HighLife SAS, France)Two separate components: nitinol alloy‐based self‐expanding frame with a trileaflet valve of bovine pericardium tissue and a subannular implantTransapical/transatrial (transseptal approach under development)Anecdotal casesAnecdotal casesHighLife Transcatheter Mitral Valve Replacement System Study (NCT02974881); still recruitingSAPIEN M3 (Edwards Lifesciences Inc)Nitinol docking system and a modified SAPIEN 3 valveTransseptalInitial results (n=15)Technical success, 86.7%Mortality at 30 d, 0%Early feasibility study (NCT03230747); recruitment not knownCardiovalve (Cardiovalve, Israel)Dual nitinol frame with a trileaflet bovine pericardium valveTransseptalInitial results (n=5)Technical success, 100%Mortality at 30 d, 60%AHEAD (European Feasibility Study of the Cardiovalve Transfemoral Mitral Valve System) (NCT03339115); still recruitingFeasibility Study of Patients With Severe MR Treated With the Cardiovalve TMVR System (NCT03714412); withdrawn (amended and merged with AHEAD‐EU [European Union] study)AHEAD (Cardiovalve Transfemoral Mitral Valve System) (NCT03813524); still recruitingCardiovalve Transfemoral System—FIM Study (NCT03958773); still recruitingCephea (Cephea Valve Technologies)Self‐expanding double‐disk and trileaflet bovine pericardium tissueTransseptal/transatrialPreclinical modelsFirst‐in‐human cases recently startedCephea Transseptal Mitral Valve System FIH (NCT03988946); still recruitingAltaValve (4C Medical Technologies Inc)Self‐expanding supra‐annular device, with a bovine tissue valve mounted into a spherical nitinol frameTransapicalPreclinical modelsAnecdotal first‐in‐human case (n=1)No trials ongoing; feasibility study plannedNaviGate (NaviGate Cardiac Structures Inc)Nitinol self‐expandable system with several annular wingletsTransapicalFirst‐in‐human case (n=1)No trials ongoing; use in tricuspid regurgitation rather than mitral diseaseMValve (MValve Ltd, Israel)Docking system combined with Lotus heart valveTransapicalFirst‐in‐human case (n=1)DOCK 1 (Mitral Valve Replacement With MValve Dock and Lotus) (NCT02719912); not yet recruiting, status unknownDE indicates device; FIH: first in human; FIM: first in man; TMVI: transcatheter mitral valve implantation; TMVR, transcatheter mitral valve replacement.Download figureDownload PowerPointFigure 2. Current transcatheter mitral valve replacement devices. A, CardiAQ/EVOQUE (Edwards Lifesciences Inc). B, Tiara (Neovasc Inc, Canada). C, FORTIS (Edwards Lifesciences Inc). D, Tendyne (Abbott Inc). E, Intrepid (Medtronic Inc). F, Caisson (LivaNova, UK). G, HighLife Bioprosthesis and Subannular Implant (HighLife SAS, France). H, SAPIEN M3 (Edwards Lifesciences Inc). I, Cardiovalve (Cardiovalve, Israel). J, NaviGate (NaviGate Cardiac Structures, Inc, CA).The CardiAQ (Edwards Lifesciences Inc) valve is a nitinol self‐expanding trileaflet valve, composed of bovine pericardial tissue, which was the first dedicated device for TMVR in 2012 in high‐risk patients with severe MR. The second generation of the device was used for the first time in 2014. It is the only device that offers both a transapical and transfemoral‐transseptal approach. The previous generation of CardiAQ valve was then completely abandoned, and the new redesigned version was renamed the EVOQUE valve. The EVOQUE valve offered an innovated system with 2 valve sizes and lower profile, to guarantee a transfemoral approach with enhanced maneuverability and depth control, and lower ventricular projection, to avoid LVOT obstruction. The first 2 trials in 2015 were rapidly withdrawn for commercial reasons. Currently, the Edwards EVOQUE TMVR Early Feasibility Study (NCT02718001) is recruiting: it will assess feasibility at 30 days. Recently, the RELIEF (Reduction or Elimination of Mitral Regurgitation in Degenerative or Functional Mitral Regurgitation With the CardiAQ‐Edwards™ Transcatheter Mitral Valve)=CardiAQ‐Edwards TMVR Study (NCT02722551) was stopped by the Edwards Company for further design validation. This stop could delay the Conformité Européene (CE) marker in Europe approval that was initially expected for 2018. From the first results presented, 13 patients have been treated under compassionate use, with a technical success (defined as successful valve delivery, valve deployment, and delivery system retrieval) of 92% and a high rate (45%) of mortality at 30 days.49, 50The Tiara (Neovasc Inc, Canada) valve is a self‐expanding trileaflet bioprosthesis of bovine pericardial tissue leaflets, mounted inside a nitinol alloy frame. This valve fits the asymmetric D‐shaped mitral annulus and has a large atrial skirt aimed at preventing PVLs. The first implant was performed in Vancouver in 2014. The TIARA‐I (Early Feasibility Study of the Neovasc Tiara Mitral Valve System) (NCT02276547) is still enrolling patients, as well as the latest TIARA‐II (Tiara Transcatheter Mitral Valve Replacement Study). Preliminary results in 71 patients, mostly in functional MR (61%), showed 94% technical success, with a mortality rate of 11.3% at 30 days.51, 52The FORTIS (Edwards Lifesciences Inc) valve is a self‐expanding bioprosthesis of bovine pericardial tissue. The first implant was performed in 2014, and results on 13 patients showed procedural success in 76.9%.53 In the early experience, valve thrombosis was often documented. For t
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