Early clinical results with the Tendyne transcatheter mitral valve replacement system

Transcatheter Mitral Valve Therapies in Patients with Mitral Annular Calcification

Mitral annular calcification is a chronic process involving degeneration and calcium deposition within the fibrous skeleton of the mitral valve annulus, which can lead to mitral valve dysfunction. It can be asymptomatic, or it can have pathologic sequelae leading to cardiovascular morbidity and mortality. Mitral annular calcification is increasingly recognized with the advancement of diagnostic imaging modalities, especially in an era with a growing elderly population. Its presence poses considerable challenges in terms of surgical and transcatheter management. Multiple surgical and transcatheter techniques have been developed to overcome these challenges. New transcatheter technologies are under investigation to tackle this problem.

Contemporary experience of mitral transcatheter edge-to-edge repair technology in patients with mitral annular calcification

BACKGROUND

Mitral annular calcification (MAC) has been an exclusion for many of the earlier pivotal trials that were instrumental in gaining device approval and indications for mitral transcatheter edge-to-edge repair (M-TEER).

AIMS

To evaluate the impact of MAC on the procedural durability and success of newer generation MitraClip® systems (G3 and G4 systems).

METHODS

Data were collected from Northwell TEER registry. Patients that underwent M-TEER with third or fourth generation MitraClip device were included. Patients were divided into -MAC (none-mild) and +MAC (moderate-severe) groups. Procedural success was defined as ≤ grade 2 + mitral regurgitation (MR) postprocedure, and durability was defined as ≤ grade 2 + MR retention at 1 month and 1 year. Univariate analysis compared outcomes between groups.

RESULTS

Of 260 M-TEER patients, 160 were -MAC and 100 were +MAC. Procedural success was comparable; however, there were three patients who required conversion to cardiac surgery during the index hospitalization in the +MAC group versus none in the -MAC group (though this was not statistically significant). At 1-month follow-up, there were no significant differences in MR severity. At 1-year follow-up, +MAC had higher moderate-severe MR (22.1% vs. 7.5%; p = 0.002) and higher mean transmitral gradients (5.3 vs. 4.0 mmHg; p = 0.001) with no differences in mortality, New York Heart Association functional class or ejection fraction.

CONCLUSION

In selective patients with high burden of MAC, contemporary M-TEER is safe, and procedural success is similar to patients with none-mild MAC. However, a loss of procedural durability was seen in +MAC group at 1-year follow-up. Further studies with longer follow-ups are required to assess newer mTEER devices and their potential clinical implications in patients with a high burden of MAC.

Transcatheter mitral valve implantation using the Tendyne valve in a patient with prior transcatheter aortic valve implantation: a case report

Background

The presence of aortic and mitral disease in a patient who is not a suitable candidate for surgical correction poses significant challenges in the diagnostic workup as well as management plans. Percutaneous treatment can be staged to fix the aortic valve with transcatheter aortic valve implantation (TAVI) as a first step, followed by reassessment and percutaneous correction of mitral regurgitation (MR).

Case summary

A 65-year-old female with multiple co-morbidities presented with acute coronary syndrome and heart failure. She was diagnosed with three-vessel coronary artery disease and degenerative low-flow low-gradient severe aortic stenosis, along with severe degenerative MR with a left ventricular ejection fraction of 35%. Because of the high surgical risk, she underwent multi-vessel percutaneous coronary intervention with stenting. Transcatheter aortic valve implantation was done as a staged procedure, which partially improved her symptoms. Mitral regurgitation was not suitable for percutaneous mitral valve edge-to-edge repair. After a discussion by the heart team, she underwent transcatheter mitral valve implantation, for which the Tendyne mitral valve (Tendyne™; Abbott) was used through a transapical approach. There was no paravalvular leak, and the mean gradient across the valve was 2 mmHg. She was symptomatically better at follow-up and an echocardiogram showed a normally functioning aortic valve and Tendyne mitral valves.

Discussion

Transapical transcatheter mitral valve implantation using the Tendyne valve is a feasible option for patients with prior TAVI. This can be considered an alternative treatment for MR in patients who are not suitable for edge-to-edge mitral repair.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

First-in-man concomitant mitral valve replacement and coronary artery bypass grafting using a single minimally invasive access

We present the case of a 78-year old woman suffering from coronary artery disease (CAD) and secondary severe mitral valve regurgitation (MR) due to left ventricular and annular distention. The interdisciplinary heart-team recommended a simultaneous hybrid procedure consisting of a minimally invasive direct coronary artery bypass grafting (MIDCABG) with subsequent transapical mitral valve replacement (TMVR) using the TendyneTM (Abbott Vascular, Santa Clara, CA, USA) prosthesis via the same small anterolateral thoracotomy. Surgery was performed in a heart team approach with close collaboration between heart surgeons and cardiologists in the hybrid theatre. Intra- and postoperative course was uneventful. Pre-discharge transthoracic echocardiography on postoperative day 8 revealed an immaculate function of the implanted valve without para- or transvalvular insufficiency, a mean gradient of 2 mmHg, no left ventricular outflow tract (LVOT) obstruction and a stable ejection fraction of 50%. The combination of MIDCABG revascularization with concomitant transapical TMVR is feasible and enables a further step towards minimally invasive therapy in even complex situations. It shows, that the modern heart-team approach exceeds mere decision-making but expands towards a hybrid patient treatment.

Design Variation, Implantation, and Outcome of Transcatheter Mitral Valve Prosthesis: A Comprehensive Review

The transcatheter mitral valve prosthesis is ideally suited for patients with inoperable mitral etiology. The transcatheter mitral valve implantation (TMVI) procedure has closely followed the evolution of transcatheter aortic procedures. There are considerable design variations amongst the limited TMVI prostheses currently available, and the implantation profiles of the devices are notably different. This comprehensive review will provide an overview of the current clinically tried TMVI devices with a focused outcome analysis. In addition, we have discussed the various design characteristics of TMVI and its associated failure mode, implantation technology, delivery methods, first-in-man trials, and pivotal trial summary for the synthesis of recent evidence.

Transcatheter mitral valve interventions

While there are dozens of novel transcatheter mitral devices in various stages of development, they remain years away from FDA approval. The existing approved transcatheter mitral interventions-transcatheter edge to edge repair for primary and secondary mitral regurgitations and transcatheter mitral valve-in-valve and valve-in-ring procedures for failing surgical prostheses-have seen a marked increase in both use and published data over the past several years. Transcatheter edge to edge repair with MitraClip has revolutionized the management of functional mitral regurgitation in heart failure with demonstrated reductions in mortality and heart failure hospitalization and is an appropriate option for patients with primary mitral regurgitation at high or prohibitive surgical risk. In patients with failing surgical mitral prostheses transcatheter mitral valve-in-valve and valve-in-ring procedures are an appealing alternative to repeat mitral valve surgery. Existing data and relevant concerns for these procedures are discussed herein.

Current devices and interventions in mitral regurgitation

Mitral regurgitation (MR) is the most common valvular disease. With a rising incidence in older age, the prevalence of relevant comorbidities inevitably increases. Considering the constantly aging population with high surgical risk, transcatheter therapy of MR is gaining increasing importance. Interventional therapy of either primary or secondary MR represents an alternative to pure drug or surgical therapy. With mitral valve transcatheter edge-to-edge repair, a well-established treatment has evolved in the past two decades. In addition, direct or indirect annuloplasty and ultimately transcatheter mitral valve implantation further expand the armamentarium. The current broad spectrum of interventional therapy options allows for patient-oriented therapy individually targeting different MR pathologies. This review discusses the current landscape of transcatheter therapies for relevant MR.

Transcatheter Heart Valves: A Biomaterials Perspective

Heart valve disease is prevalent throughout the world, and the number of heart valve replacements is expected to increase rapidly in the coming years. Transcatheter heart valve replacement (THVR) provides a safe and minimally invasive means for heart valve replacement in high-risk patients. The latest clinical data demonstrates that THVR is a practical solution for low-risk patients. Despite these promising results, there is no long-term (>20 years) durability data on transcatheter heart valves (THVs), raising concerns about material degeneration and long-term performance. This review presents a detailed account of the materials development for THVRs. It provides a brief overview of THVR, the native valve properties, the criteria for an ideal THV, and how these devices are tested. A comprehensive review of materials and their applications in THVR, including how these materials are fabricated, prepared, and assembled into THVs is presented, followed by a discussion of current and future THVR biomaterial trends. The field of THVR is proliferating, and this review serves as a guide for understanding the development of THVs from a materials science and engineering perspective.

Transcatheter Mitral Valve Replacement: Current Evidence and Concepts

Over the past decade, several transcatheter devices have been developed to address the treatment of severe mitral regurgitation (MR) in patients at high surgical risk, mainly aimed at repairing the native mitral valve (MV). MV repair devices have recently been shown to have high efficacy and safety. However, to replicate promising trial results, specific anatomical and pathophysiological criteria have to be met and operators need a high level of experience. As yet, the longer-term durability of transcatheter MV repair remains unknown. Transcatheter MV replacement (TMVR) might be a treatment option able to target various anatomies, reliably abolish MR, and foster ease of use with a standardised implantation protocol. This review presents upcoming TMVR devices and available data and discusses how TMVR might further advance the field of transcatheter treatment of MR.

Mitral Regurgitation in Patients With Coexisting Chronic Aortic Regurgitation: An Evidence-Based Narrative Review

Chronic aortic regurgitation (AR) frequently leads to significant downstream changes to the left ventricle and pulmonary vasculature; these structural and physiologic changes result in lower- than expected patient survival. Progressive, uncorrected AR can lead to left ventricle dilation and subsequent mitral valve leaflet tethering, as well as mitral annular dilation, resulting in secondary mitral regurgitation (MR) in up to 45% of patients. Surgical aortic valve replacement (AVR) improves secondary MR in most patients, but survival is significantly lower in those patients who do not show improvement in MR after AVR. Thus, there is considerable debate on whether the mitral valve should be intervened upon at the time of the AVR. In this review, the authors address the long-term outlook for patients with chronic AR and concurrent MR. The authors also review the available evidence on concomitant mitral valve surgery in patients undergoing AVR for AR. Lastly, this narrative review examines the recent advances in transcatheter mitral valve repair and replacement, and explores the potential role of transcatheter mitral therapies in patients with secondary MR due to AR.

Surgical versus transcatheter mitral valve replacement in functional mitral valve regurgitation

Surgical mitral valve intervention for severe functional, or secondary mitral regurgitation is a viable option for patients deemed to be operative candidates and can be performed via traditional sternotomy or by minimally invasive techniques with similar outcomes. Transcatheter mitral valve replacement is an emerging technology with a potential role in the treatment of functional mitral valve regurgitation. A plethora of devices are currently in development and in various stages of clinical investigation. Operative approach to transcatheter mitral valve replacement varies from a percutaneous transseptal approach to a hybrid percutaneous/surgical apical approach. The Tendyne, Intrepid and Evoque systems show promising results from their early feasibility studies in treatment of patients with mitral regurgitation that were too high risk for surgery. In this review, we describe considerations for surgical and transcatheter mitral valve replacement for functional mitral valve regurgitation.

Cross-linking method using pentaepoxide for improving bovine and porcine bioprosthetic pericardia: A multiparametric assessment study

Bioprosthetic heart valves made from bovine pericardium (BP) and porcine pericardium (PP) preserved with glutaraldehyde (GA) are commonly used in valve surgeries but prone to calcification in many patients. In this study, we compared BP and PP preserved with GA, ethylene glycol diglycidyl ether (DE), and 1,2,3,4,6-penta-O-{1-[2-(glycidyloxy)ethoxy]ethyl}-d-glucopyranose (PE). We studied the stabilities of DE and PE in preservation media along with the amino acid (AA) compositions, Fourier-transform infrared spectra, mechanical properties, surface morphologies, thermal stability, calcification, and the cytocompatibility of BP and PP treated with 0.625% GA, 5% DE, 2% PE, and alternating 5% DE and 2% PE for 3 + 11 d and 10 + 10 d, respectively. Both epoxides were stable in the water-buffer solutions (pH 7.4). DE provided high linkage densities in BP and PP owing to reactions with Hyl, Lys, His, Arg, Ser, and Tyr. PE reacted weakly with these AAs but strongly with Met. High cross-linking density obtained using the 10 d + 10 d method provided satisfactory thermal stability of biomaterials. The epoxy preservations improved cytocompatibility and resistance to calcification. PE enhanced the stress/strain properties of the xenogeneic pericardia, perhaps by forming nanostructures that were clearly visualised in BP using scanning electron microscopy. The DE + PE combination, in an alternating cross-linking manner, thus constitutes a promising option for developing bioprosthetic pericardia.

Transcatheter Mitral Valve Replacement: Procedural Planning, Utility, and Applicability

Since the first native transcatheter mitral valve implantation in 2012, transcatheter mitral valve replacement (TMVR) has expanded its use to degenerated bioprostheses, failed annuloplasty ring repair, and mitral annular calcification. However, high-screen failure rates in trials have persisted due to predicted left ventricular outflow tract obstruction and unfavorable anatomy. Preprocedural planning in this patient population with multidetector computed tomography and transesophageal echocardiography is paramount to intraprocedural success. In patients with favorable left ventricular outflow tract anatomy who are not surgical candidates, the transseptal approach is preferred. In those who are surgical candidates, TMVR can be performed via a transapical or transatrial approach. Currently, a plethora of TMVR devices targeting the native mitral pathologies are undergoing clinical trials. Data have consistently shown the greatest benefit of this procedure in native mitral regurgitation and failed bioprostheses rather than failed annuloplasty rings or mitral annular calcification. With technological advancement and careful patient selection, this therapy will serve as a complement to surgical and TMV repair and will continue to expand to address MV diseases in a broader patient population.

Percutaneous Interventions for Secondary Mitral Regurgitation

Mitral regurgitation is frequently associated with ventricular dysfunction and carries a high mortality. Guideline-directed medical therapy, surgical mitral valve repair or replacement, and, in the setting of advanced heart failure, heart transplant and left ventricular assist devices have been the mainstay of treatment. However, rapid advancement in the field has resulted in approval of edge-to-edge mitral valve repair with the MitraClip, and there are several novel catheter-based percutaneous options in clinical trials. Percutaneous options, while promising, must be deployed in patients who are most likely to benefit, and thus, understanding the pathophysiology of specific subgroups of patients with functional mitral regurgitation (eg, disproportionate versus proportionate mitral regurgitation) is key to the success of new devices. We review the pathophysiology, percutaneous therapeutic treatment options, and ongoing clinical trials for functional mitral regurgitation.

Fusion imaging for transcatheter mitral and tricuspid interventions

Image guidance for transcatheter mitral and tricuspid valve intervention commonly utilizes the unique advantages of both fluoroscopy and live echocardiography. In some cases, pre-procedural computed tomography is also needed. Classically, they are displayed separately even if modalities are in simultaneous use. This requires procedural operators to watch separate images displaying complementary information and mentally combine these data sources. New hybrid, or fusion, imaging systems allow for multiple imaging modalities to be overlaid on one another to provide the most relevant information on a single screen. While this technological advancement may have some advantages in certain procedures, more data is needed to understand if these systems will improve procedural or clinical outcomes.

Minimally invasive mitral valve surgery is associated with a low rate of complications

Minimally invasive mitral valve surgery is generally performed through a right minithoracotomy, in contrast to the traditional full median sternotomy approach. Minimally invasive mitral valve surgery is performed with increasing frequency, and by reducing surgical trauma, several observational studies suggest potential benefits with decreased bleeding and postoperative pain, reduced incidence of sternal wound infections, reduced length of hospital stay and shortened recovery period after surgery. In this review, we present an overview of mitral valve surgery, summarize the available evidence regarding the minimally invasive approach and report our experiences from introducing a minimally invasive mitral valve surgery programme at the Karolinska University Hospital in Stockholm, Sweden.

Functional Mitral Regurgitation in Heart Failure

Functional mitral regurgitation (FMR) in the setting of left ventricular (LV) dysfunction and heart failure portends a poor prognosis. Guideline-directed medical therapy remains the cornerstone of initial treatment, with emphasis placed on treatment of the underlying LV dysfunction, as FMR is a secondary phenomenon and a disease due to LV remodeling. Surgical correction of FMR is controversial because it typically does not address the underlying mechanism and etiology of the condition. However, new, minimally invasive transcatheter therapies, in particular the MitraClip system, have shown promise in the treatment of FMR in selected patients. This review will summarize the pathophysiology underlying FMR, the prognosis of patients with heart failure and FMR, and the various medical and procedural treatment options currently available and under investigation.

The Year in Perioperative Echocardiography: Selected Highlights from 2018

This article is the third of an annual series reviewing the research highlights of the year pertaining to the subspecialty of perioperative echocardiography for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series. In most cases, these will be research articles targeted at the perioperative echocardiography diagnosis and treatment of patients after cardiothoracic surgery; but in some cases, these articles will target the use of perioperative echocardiography in general.