Early Experience With a Novel Transfemoral Mitral Valve Implantation System in Complex Degenerative Mitral Regurgitation

Outcomes Following Transcatheter Mitral Valve Replacement Using Dedicated Devices in Patients With Mitral Annular Calcification

BACKGROUND

Patients with mitral regurgitation (MR) and morphologic presence of relevant mitral annular calcification (MAC) represent a challenging phenotypic subset with limited treatment options.

OBJECTIVES

The aim of this study was to assess the feasibility of transcatheter mitral valve replacement (TMVR) using dedicated devices for the treatment of MAC patients.

METHODS

Consecutive patients with symptomatic MR receiving TMVR and with available computed tomography data from the CHOICE-MI (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency) multicenter registry were stratified by the presence of none or mild mitral annular calcification (MACnone/mild) vs moderate or severe mitral annular calcification (MACmod/sev).

RESULTS

Among 279 eligible patients (median age = 76.0 years [Q1-Q3: 71.0-81.0 years], EuroSCORE II = 6.2% [Q1-Q3: 3.9%-12.1%]), 222 (79.6%) presented with MACnone/mild and 57 (20.4%) with MACmod/sev. Patients with MACmod/sev had a higher prevalence of extracardiac arteriopathy (P = 0.011) and primary MR (P < 0.001). Although the technical success rate and the extent of MR elimination did not differ, TMVR treatment in MACmod/sev patients was associated with higher rates of postprocedural bleeding complications (P = 0.02) and renal failure (P < 0.001). Functional improvement at the 1- and 2-year follow-up did not differ between groups. At the 2-year follow-up, there were no differences between patients with MACmod/sev and MACnone/mild regarding all-cause mortality (38.5% vs 37.7%; P = 0.76), cardiovascular mortality (21.3% vs 24.9%; P = 0.97), and all-cause mortality or heart failure hospitalization (52.4% vs 46.7%; P = 0.28) CONCLUSIONS: TMVR in patients with MACmod/sev is associated with higher rates of postprocedural complications but similar rates of survival, MR resolution, and functional improvement compared to MACnone/mild. Further studies are necessary to define the role of dedicated TMVR devices in this population. (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency Registry [CHOICE-MI]; NCT04688190).

Transcatheter Therapy for Mitral Valve Stenosis

Mitral valve stenosis remains highly prevalent among the US population although with dramatically shifting demographics. The significance of rheumatic mitral disease in developing nations persists, despite improvements in preventative measures and early detection, and its presence in developed countries is still evident as observed through international migration. In addition, the substantial growth in the aging population with a heightened occurrence of concurrent cardiovascular risk factors is leading to an increased prevalence of chronic calcific degeneration and degeneration of previously repaired or replaced valves. This article aims to review various transcatheter therapies in the treatment of mitral valve stenosis.

Transcatheter Therapy for Mitral Valve Stenosis

Mitral valve stenosis remains highly prevalent among the US population although with dramatically shifting demographics. The significance of rheumatic mitral disease in developing nations persists, despite improvements in preventative measures and early detection, and its presence in developed countries is still evident as observed through international migration. In addition, the substantial growth in the aging population with a heightened occurrence of concurrent cardiovascular risk factors is leading to an increased prevalence of chronic calcific degeneration and degeneration of previously repaired or replaced valves. This article aims to review various transcatheter therapies in the treatment of mitral valve stenosis.

1-Year Outcomes Following Transfemoral Transseptal Transcatheter Mitral Valve Replacement: The HighLife TSMVR Feasibility Study

BACKGROUND

A significant number of patients with severe mitral regurgitation (MR) are not suitable for either surgical or transcatheter edge-to-edge repair because of high surgical risk or inappropriate mitral valve anatomy.

OBJECTIVES

The aim of this study was to evaluate the HighLife Trans-Septal Mitral Valve Replacement (TSMVR) system in patients with symptomatic MR and high surgical risk.

METHODS

This prospective, multicenter, nonrandomized feasibility study evaluated the safety and performance of the HighLife TSMVR system in patients with moderate to severe or severe symptomatic MR during 1-year follow-up. Echocardiographic data were assessed at an independent core laboratory.

RESULTS

A total of 30 patients (mean age 75.6 years, 27% women, median Society of Thoracic Surgeons score 5.5%) with severe MR (90% with secondary MR, median left ventricular ejection fraction 43%) were treated at 13 sites. In 27 of the 30 patients, the HighLife TSMVR system was implanted successfully (technical success rate 90%). Device success at 30 days was 83%. After 1 year, 5 patients (17%) had died. None of the patients who underwent implantation required mitral valve reintervention. All patients who underwent implantation had no or trace (78%) or mild (22%) MR, the mean gradient of the HighLife valve was 5.1 mm Hg, and there were no signs of left ventricular outflow tract obstruction (mean gradient 2.0 mm Hg).

CONCLUSIONS

The 1-year results from the HighLife TSMVR feasibility study demonstrate a high technical success rate, excellent valve function, no left ventricular outflow tract obstruction, and no need for mitral valve reintervention. Additional patient outcomes and longer follow-up are needed to confirm these findings. (Expanded Study of the HighLife 28mm Trans-Septal Trans-Catheter Mitral Valve in Patients With Moderate-Severe or Severe Mitral Regurgitation and at High Surgical Risk; NCT04029363).

Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valve or Dedicated Devices: Current Evidence and Future Prospects

Transcatheter mitral valve replacement (TMVR) is a novel and evolving field dedicated to addressing the therapeutic challenges posed by patients at high surgical risk with mitral valve disease. TMVR can be categorized into two distinct fields based on the type of device and its specific indications: TMVR with transcatheter aortic valves (TAV) and TMVR with dedicated devices. Similar to aortic stenosis, TMVR with TAV requires a rigid support structure to secure the valve in place. As a result, it is indicated for patients with failing bioprothesis or surgical rings or mitral valve disease associated with severe mitral annular calcification (MAC), which furnishes the necessary foundation for valve anchoring. While TMVR with TAV has shown promising outcomes in valve-in-valve procedures, its effectiveness remains more contentious in valve-in-ring or valve-in-MAC procedures. Conversely, TMVR with dedicated devices seeks to address native mitral regurgitation, whether accompanied by MAC or not, providing an alternative to Transcatheter Edge-to-Edge Repair (TEER) when TEER is not feasible or expected to yield unsatisfactory results. This emerging field is gradually surmounting technical challenges, including anchoring a valve in a non-calcified annulus and transitioning from the transapical route to the transeptal approach. Numerous devices are presently undergoing clinical trials. This review aims to furnish an overview of the supporting evidence for TMVR using TAV in each specific indication (valve-in-valve, valve-in-ring, valve-in-MAC). Subsequently, we will discuss the anticipated benefits of TMVR with dedicated devices over TEER, summarize the characteristics and clinical results of TMVR systems currently under investigation, and outline future prospects in this field.

Update on Transcatheter Treatment of Mitral and Tricuspid Valve Regurgitation

PURPOSE OF REVIEW

Mitral and tricuspid regurgitation represents a clinical challenge. They are associated with a poor prognosis, and many patients are not eligible for conventional surgery. Transcatheter therapies have been the focus of numerous studies and devices over the past decade. Here, we provide a summary of current options for transcatheter treatment of these 2 entities.

RECENT FINDINGS

Recent studies have demonstrated the benefits of edge-to-edge repair for increasing numbers of patients. Encouraging early results with transcatheter valve replacement are also becoming available. To date, transcatheter edge-to-edge repair is currently the first-line transcatheter treatment for both mitral and tricuspid regurgitation for many patients who are not candidates for surgery. A number of transcatheter replacement devices are under development and clinical investigation but, for the most part, their current use is limited to compassionate cases or clinical trials.

Transfemoral Transcatheter Mitral Valve Implantation With a Dedicated Device in a Rheumatic Mitral Stenosis Patient

A 65-year-old obese woman with rheumatic heart disease and restrictive lung disease presented with decompensated heart failure. Evaluation demonstrated severely thickened mitral valve leaflets, severe mitral stenosis, and moderate mitral regurgitation. She underwent successful transfemoral transseptal transcatheter mitral valve replacement with a dedicated valve resulting in improved functional status. (Level of Difficulty: Advanced.).

Mitral Interventions in Heart Failure

Patients with heart failure with reduced ejection fraction who have secondary mitral regurgitation (SMR) have poorer outcomes and quality of life than those without SMR. Guideline-directed medical therapy is the cornerstone of SMR treatment. Careful evaluation of landmark trials using mitral transcatheter edge-to-edge repair in SMR has led to an improved understanding of who will benefit from percutaneous interventions with emphasis on a multidisciplinary approach. The success with mitral transcatheter edge-to-edge repair in SMR has also spurred the evaluation of its role in populations that were not initially studied, such as end-stage heart failure and cardiogenic shock. A spectrum of transcatheter devices in development and clinical trials promise to further provide a growing array of management options for heart failure with reduced ejection fraction patients with symptomatic SMR.

Current status of transcatheter mitral valve replacement: systematic review and meta-analysis

Introduction

Mitral Regurgitation (MR) has a strong impact on quality of life and on mid-term survival. Transcatheter mitral valve replacement (TMVR) is rapidly expanding and a growing number of studies have been published recently.

Methods

A systematic review of studies reporting on clinical data for patients with symptomatic severe MR undergoing TMVR was performed. Early- and mid-term outcomes (clinical and echocardiographic) were evaluated. Overall weighted means and rates were calculated. Risk ratios or mean differences were calculated for pre- and post-procedural comparisons.

Results

A total of 12 studies and 347 patients who underwent TMVR with devices clinically available or under clinical evaluation were included. Thirty-day mortality, stroke and major bleeding rates were 8.4%, 2.6%, and 15.6%, respectively. Pooled random-effects demonstrated a significant reduction of ≥ grade 3+ MR (RR: 0.05; 95% CI: 0.02-0.11; p < 0.001) and in the rates of patients in NYHA class 3-4 after the intervention (RR: 0.27; 95% CI: 0.22-0.34; p < 0.001). Additionally, the pooled fixed-effect mean difference for quality of life based on the KCCQ score yielded an improvement in 12.9 points (95% CI:7.4-18.4, p < 0.001), and exercise capacity improved by a pooled fixed-effect mean difference of 56.8 meters in the 6-minute walk test (95% CI 32.2-81.3, p < 0.001).

Conclusions

Among 12 studies and 347 patients comprising the updated evidence with current TMVR systems there was a statistically significant reduction in ≥ grade 3+ MR and in the number of patients exhibiting poor functional class (NYHA 3 or 4) after the intervention. Overall rate of major bleeding was the main shortcoming of this technique.

Transcatheter Mitral Valve Replacement with Dedicated Devices

Mitral regurgitation is the most common form of valvular heart disease. The anatomy and pathophysiology of mitral valve regurgitation are very complex, and dedicated devices are required for transcatheter mitral valve replacement in patients with a high or prohibitive surgical risk. In the United States, all transcatheter mitral valve replacement devices are still being studied and are not yet approved for commercial use. Early feasibility studies have demonstrated good technical success and short-term outcomes, but larger samples and longer-term outcomes still need to be assessed. Furthermore, significant advances in device technology, delivery systems, and implantation techniques are essential to avoid left ventricular outflow tract obstruction, and valvular and paravalvular regurgitation as well as ensuring good anchoring of the prosthesis.

Transcatheter Treatment of Mitral Regurgitation

Mitral valve disease, and in particular mitral regurgitation, is a common clinical entity. Until recently, surgical repair and replacement were the only therapeutic options available, leaving many patients untreated mostly due to excessive surgical risk. Over the last number of years, huge strides have been made regarding percutaneous, catheter-based solutions for mitral valve disease. Transcatheter repair procedures have most commonly been used, and in recent years there has been exponential growth in the number of devices available for transcatheter mitral valve replacement. Furthermore, the evolution of these devices has resulted in both smaller delivery systems and a shift towards transeptal access, negating the need for surgical incisions. In line with these advancements, and clinical trials demonstrating promising outcomes in carefully selected cases, recent guidelines have strengthened their recommendations for these devices. It is appropriate, therefore, to now review the current transcatheter repair and replacement devices available and the evidence for their use.

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.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021255241, identifier: CRD42021255241.

Latest Advances in Transcatheter Mitral Valve Replacement

Mitral regurgitation (MR) is the most prevalent valvular heart disease globally. Mitral valve surgery is the gold-standard treatment for MR. However, a significant portion of patients with mitral valve disease are at high or prohibitive surgical risk. Transcatheter mitral valve replacement (TMVR) has emerged as a potential treatment option for this vulnerable population. Numerous TMVR devices are currently being investigated, with early data demonstrating feasibility and efficacy of TMVR. In this article, we explore the unique challenges of designing a TMVR system and describe the TMVR systems under clinical evaluation.

Thirty-Day Outcomes Following Transfemoral Transseptal Transcatheter Mitral Valve Replacement: Intrepid TMVR Early Feasibility Study Results

OBJECTIVES

To evaluate outcomes of transcatheter mitral valve replacement (TMVR) with transfemoral access in patients at prohibitive or high surgical risk.

BACKGROUND

Prohibitive surgical risk may preclude MVR surgery in some patients. The investigational Intrepid TMVR system (Medtronic, Minneapolis, MN) has previously been evaluated using transapical access for delivery of a self-expanding bioprosthetic valve.

METHODS

This prospective, multi-center, non-randomized early feasibility study (EFS) evaluated safety and performance of the Intrepid valve using transfemoral/transseptal access in patients with moderate-severe/severe, symptomatic mitral regurgitation (MR) at high surgical risk. Candidacy was determined by heart teams with approval by a central screening committee. Echocardiographic data were evaluated by an independent core laboratory. Clinical events were adjudicated by a clinical events committee.

RESULTS

Fifteen patients were enrolled at 6 sites from Feb 2020-May 2021. Median age was 80 years and STS-PROM was 4.7%; 87% were male and 53% had prior sternotomy. Fourteen implants were successful. One patient converted to surgery during the index procedure. Patients stayed a median 5 days post-procedure. There were 6 (40%) access site bleeds and 11 (73%) iatrogenic ASD closures. At 30 days, there were no deaths, strokes, or reinterventions. All implanted patients had trace/no valvar or paravalvar MR and mean gradient was 4.7±1.8 mmHg.

CONCLUSIONS

Thirty-day results from the Intrepid transfemoral TMVR EFS demonstrate excellent valve function and no mortality or stroke. Additional patients and longer follow-up are needed to confirm these findings.

Device Therapy in Chronic Heart Failure: JACC State-of-the-Art Review

The regulatory landscape for device-based heart failure (HF) therapies has seen a major shift in the last 7 years. In 2013, the U.S. Food and Drug Administration released guidance for early feasibility and first-in-human studies, thereby encouraging device innovation, and in 2016 the U.S. Congress authorized the Breakthrough Devices Program to expedite access for Americans to innovative devices indicated for diagnosis and treatment of serious illnesses, such as HF. Since December 2016, there has been an increase in the number of HF devices for which manufacturers are seeking approval through the breakthrough designation pathway. This has led to a rapid uptake in the development and evaluation of device-based HF therapies. This article reviews the current and future landscape of device therapies for chronic HF and associated comorbidities and the regulatory environment that is driving current and future innovation.

Transcatheter mitral valve replacement: an update

PURPOSE OF REVIEW

A significant number of patients with mitral valve disease are at high to prohibitive risk for surgical repair or replacement. Transcatheter mitral valve interventions have evolved over the last few years. We review the recent growing evidence on transcatheter mitral valve replacement (TMVR).

RECENT FINDINGS

Tendyne is the first TMVR device commercially approved in Europe. All TMVR systems remain under investigation in the United States. Several early studies have reported the feasibility and safety outcomes for TMVR implanted via transapical or transseptal approach. TMVR using balloon expandable valve for degenerated bioprosthetic valves, surgical rings and mitral annular calcification appears feasible in selected patients.

SUMMARY

Early experience with TMVR systems is promising. Larger ongoing studies will help understand longer term outcomes and offer insights into patient selection.

Current Status and Future Prospects of Transcatheter Mitral Valve Replacement: JACC State-of-the-Art Review

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, it confers a poorer prognosis. Catheter-based repair therapies face some limitations like their applicability on challenging anatomies and the potential recurrence of significant MR over time. Transcatheter mitral valve replacement (TMVR) has emerged as a less invasive approach potentially overcoming some of the current limitations associated with transcatheter mitral valve repair. Several devices are under clinical investigation, and a growing number of systems allow for a fully percutaneous transfemoral approach. In this review, the authors aimed to delineate the main challenges faced by the TMVR field, to highlight the key aspects for procedural planning, and to describe the clinical results of the TMVR systems under clinical investigation. Finally, they also discuss what the future perspectives are for this emerging field.

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.