Percutaneous Transcatheter Mitral Valve Replacement: First-in-Human Experience With a New Transseptal System

Etiologies and Impact of Exclusion Rates for Transcatheter Mitral and Tricuspid Valve Structural Heart Clinical Trials at a High-Volume Quaternary Care Hospital

There are various devices under clinical investigation for transcatheter mitral valve intervention and transcatheter tricuspid valve intervention (TTVI); however, the exclusion rates remain high. We aimed to investigate the exclusion rates for transcatheter mitral valve repair (TMVr), transcatheter mitral valve replacement (TMVR), transcatheter tricuspid valve repair (TTVr), and transcatheter tricuspid valve replacement (TTVR). There were 129 patients who were referred to St. Francis Hospital & Heart Center valve clinic and completed screening between January 2021 and July 2022. The causes for exclusion were classified into 4 categories: patient withdrawal, anatomic unsuitability, clinical criteria, and medical futility. In 129 patients, the exclusion rates for TMVr, TMVR, TTVr, and TTVR were 81%, 85%, 91%, and 87%, respectively. Patient withdrawal and medical futility were leading etiologies for exclusion, followed by anatomic unsuitability. TMVr had the highest rate of patient withdrawal (64%) and the lowest anatomic unsuitability (5%) because of short posterior leaflet length. Replacement interventions have a higher anatomic unsuitability (33%) than repair interventions (17%) (p = 0.04). Most exclusions of anatomic unsuitability were because of mitral stenosis or small annulus size for TMVR and large annulus size for TTVR. A total of 50% of exclusions from TTVr were because of the presence of pacemaker/defibrillator leads. In patients excluded from their respective trials, patients being referred for TMVr had the highest recurrent hospitalization and repair group had a higher mortality (p <0.01 and p = 0.01, respectively). In conclusion, the exclusion rates for transcatheter mitral valve intervention and TTVI trials remain high because of various reasons, limiting patient enrollment and treatment. This supports the need for further device improvement or exploring alternative means of therapy.

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.

Orthotopic Transcatheter Mitral Valve Replacement

Mitral valve dysfunction is prevalent amongst older patients. Of those not suitable for surgical therapy, mitral transcatheter edge-to-edge repair (TEER) can treat as large proportion of patients, many are not suitable TEER candidates. As such, orthotopic transcatheter mitral valve replacement (TMVR) is an important innovation but it faces significant challenges. Orthotopic TMVR requires a prosthesis with stable anchoring, adequate sealing, minimal footprint in the left ventricle and long term durability. Multidisciplinary expertise in advanced imaging, surgery, heart failure are needed for success.

Transcatheter mitral valve replacement with Mi-thos system: First-in-human experience

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has become an alternative for high-risk patients with severe mitral regurgitation (MR). The aim of this study was to evaluate the safety and feasibility of the Mi-thos TMVR system (NewMed Medical) for high-risk patients with severe MR.

METHODS

This was a prospective, two-center, single-arm early feasibility study. Baseline characteristics, procedural data and 30-day follow-up outcomes were collected and analyzed. The primary endpoint was intraoperative success rate of device implantation. The second endpoints were all-cause mortality and major post-procedural complications. Echocardiographic data were evaluated by an independent core laboratory. Clinical events were adjudicated by a clinical events committee.

RESULTS

Ten high-risk patients with severe MR were enrolled at two sites from August 2021 to November 2022. The median age was 70.5 years, and 60% of patients were female. The median Society of Thoracic Surgeons Predicted Risk of Mortality was 9.5%. The Mi-thos TMVR system was successfully implanted via transapical access in all patients. There was no pericedural mortality or major postpericedural complications during the 30-day follow-up. All implanted prosthetic valves had no or trace valvular or paravalvular MR, and the median mitral valve gradient at 30 days was 2.0 mmHg (IQR: 2.0-3.0 mmHg). There was one mild left ventricular outflow tract obstruction.

CONCLUSIONS

The favorable short-term outcomes of the Mi-thos TMVR system demonstrated that it might be a feasible and safe therapeutic alternative for high-risk patients with severe MR. Nevertheless, further evaluation of the Mi-thos TMVR system is warranted.

Transcatheter mitral valve implantation for native valve disease

Mitral regurgitation is the second most frequent heart valve disease in Europe and the most frequent in the US. Although surgery is the therapy of choice when intervention is indicated, transcatheter mitral valve repair or replacement are alternatives for patients who are not eligible for surgery. However, the development of transcatheter mitral valves is slower than expected. Although several transcatheter heart valves have been developed, only one has been commercialised. Indeed, most of these devices are being evaluated in clinical studies, with promising initial results. In this review, we propose an overview on transcatheter mitral valve replacement for the treatment of native mitral valve disease, from indication to results, including patients with severe annular calcification, and we provide you with a glimpse into the future of these therapies.

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.

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

Transcatheter heart valve interventions for patients with rheumatic heart disease

Rheumatic heart disease [RHD] is the most prevalent cause of valvular heart disease in the world, outstripping degenerative aortic stenosis numbers fourfold. Despite this, global resources are firmly aimed at improving the management of degenerative disease. Reasons remain complex and include lack of resources, expertise, and overall access to valve interventions in developing nations, where RHD is most prevalent. Is it time to consider less invasive alternatives to conventional valve surgery? Several anatomical and pathological differences exist between degenerative and rheumatic valves, including percutaneous valve landing zones. These are poorly documented and may require dedicated solutions when considering percutaneous intervention. Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice for severe mitral stenosis (MS) but is reserved for patients with suitable valve anatomy without significant mitral regurgitation (MR), the commonest lesion in RHD. Valvuloplasty also rarely offers a durable solution for patients with rheumatic aortic stenosis (AS) or aortic regurgitation (AR). MR and AR pose unique challenges to successful transcatheter valve implantation as landing zone calcification, so central in docking transcatheter aortic valves in degenerative AS, is often lacking. Surgery in young RHD patients requires mechanical prostheses for durability but morbidity and mortality from both thrombotic complications and bleeding on Warfarin remains excessively high. Also, redo surgery rates are high for progression of aortic valve disease in patients with prior mitral valve replacement (MVR). Transcatheter treatments may offer a solution to anticoagulation problems and address reoperation in patients with prior MVR or failing ventricles, but would have to be tailored to the rheumatic environment. The high prevalence of MR and AR, lack of calcification and other unique anatomical challenges remain. Improvements in tissue durability, the development of novel synthetic valve leaflet materials, dedicated delivery systems and docking stations or anchoring systems to securely land the transcatheter devices, would all require attention. We review the epidemiology of RHD and discuss anatomical differences between rheumatic valves and other pathologies with a view to transcatheter solutions. The shortcomings of current RHD management, including current transcatheter treatments, will be discussed and finally we look at future developments in the field.

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.

Emerging Approaches to Management of Left Ventricular Outflow Obstruction Risk in Transcatheter Mitral Valve Replacement

An increasing number of patients with mitral valve disease are high risk for surgery and in need of less invasive treatments including transcatheter mitral valve replacement (TMVR). Left ventricular outflow tract (LVOT) obstruction is a predictor of poor outcome after TMVR, and its risk can be accurately predicted using cardiac computed tomography analysis. Novel treatment strategies that have shown efficacy in reducing risk of LVOT obstruction after TMVR include pre-emptive alcohol septal ablation, radiofrequency ablation, and anterior leaflet electrosurgical laceration. This review describes recent advances in the management of LVOT obstruction risk after TMVR, provides a new management algorithm, and explores forthcoming studies that will further advance the field.

Valvular Heart Disease: New Concepts in Pathophysiology and Therapeutic Approaches

This review discusses recent advancements in the field of valvular heart disease. Topics covered include recognition of the impact of atrial fibrillation on development and assessment of valvular disease, strategies for global prevention of rheumatic heart disease, understanding and management of secondary mitral regurgitation, the updated classification of bicuspid aortic valve disease, recognition of heightened cardiovascular risk associated with moderate aortic stenosis, and a growing armamentarium of transcatheter therapies.

Outcomes after Transcatheter Mitral Valve Implantation: A Literature Review

Mitral valve disease is the most common heart valve disease worldwide. Surgical mitral valve replacement or repair has been an established therapy in patients with severe mitral valve disease for many years. On the other hand, many patients with advanced mitral valve disease and severe comorbidities are treated conservatively and are excluded from the surgical procedure. Furthermore, in patients with severe comorbidities, transcatheter mitral valve repair by edge-to-edge technique with MitraClip or transcatheter mitral valve repair with a non-absorbable ring have been added as therapeutic options over the last few years. Alternative procedures for the treatment of patients with advanced prosthetic or native mitral valve diseases include transcatheter access for replacement or implantation of a new prosthetic valve in the diseased mitral valve. Promising results were published about short-term outcomes of patients who underwent the transcatheter mitral valve replacement. The current view and results of the transcatheter mitral valve implantation in patients with advanced native or prosthetic mitral valve disease are briefly discussed.

Mitral Regurgitation in the High-Risk Patient: Integrating an Expanding Armamentarium of Transcatheter Devices Into the Treatment Algorithm

Over the last decade, multiple transcatheter mitral valve repair and replacement strategies have emerged, yet there is only 1 US Food and Drug Administration approved device, the MitraClip (Abbott Vascular, Inc., Santa Clara, CA). Current guidelines support the use of the MitraClip in high or prohibitive surgical risk patients, but there are many patients that are not anatomically suited for the device. This review article discusses the approach to degenerative and functional mitral regurgitation in the high-prohibitive risk patient, how to choose transcatheter treatment options (both approved and investigational), and potential management for therapy failure.

Acute Bioprosthetic Mitral Valve Failure Diagnosed Using Point-of-Care Ultrasound Leading to Prompt Treatment and Good Outcome

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Acute bioprosthetic mitral valve failure is a medical emergency.

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POCUS can confirm the diagnosis along with a good history and physical exam.

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Early diagnosis and prompt multidisciplinary treatment will deliver the best outcome.

Transcatheter Mitral Valve Replacement in High-Surgical Risk Patients: A Single-Center Experience and Outcome

Background

Re-operative mitral valve (MV) replacement is a high-risk procedure, therefore, transcatheter MV replacement (TMVR) is a promising therapeutic option.

Aim

In this study, we aimed to evaluate the feasibility and safety of TMVR in patients with high surgical risk with degenerated mitral bioprostheses (TMViV), failed surgical rings (TMViR), and mitral annular calcification (TMViMAC).

Methods

This is a retrospective cohort study that enrolled patients with high surgical risk who underwent TMVR from February 2017 to September 2020. The TMVR procedure was performed using Edwards SAPIEN-3 valves through the transseptal approach.

Results

Sixty-four patients aged 62.7 ± 16.1 years with an STS score of 9.2 ± 3.7% underwent TMVR [35 (55%) TMViV, 16 (25%) TMViR, and 13 (20%) TMViMAC]. Mitral stenosis was more frequent in TMViV, mitral regurgitation was more frequent in TMViR, and combined mitral stenosis and regurgitation were more frequent in TMViMAC (P < 0.05). The MV gradient was 14.3 ± 5.3 mmHg and the MV area was 1.5±0.6 cm². The 29 mm valve was frequently used in TMViV and TMViMAC, while the 23 mm valve was frequently used in TMViR (P=0.003^∗). The procedural and fluoroscopy times were 58.7 ± 8.9 and 41.1 ± 8.2 minutes, respectively. Technical success was reported in 62 (98.4%) patients; 1 TMViR patient experienced valve embolization and salvage surgery, and 1 TMViMAC patient experienced slight valve malposition. At 3 months, 2 (3.1%) patients showed valve thrombosis (treated with anticoagulation), and 1 (1.6%) patient developed a paravalvular leak (underwent surgical MV replacement). At 6 months, 3 (4.7%) patients showed valve degeneration (underwent surgical MV replacement). Throughout follow-up, no patient exhibited mortality.

Conclusions

TMVR is a feasible and safe approach in patients with high surgical risk. TMViV and TMViR are reasonable as the first treatment approaches, and TMViMAC seems encouraging.

Transcatheter Mitral Valve Repair or Replacement: Competitive or Complementary?

Over the last two decades, transcatheter devices have been developed to repair or replace diseased mitral valves (MV). Transcatheter mitral valve repair (TMVr) devices have been proven to be efficient and safe, but many anatomical structures are not compatible with these technologies. The most significant advantage of transcatheter mitral valve replacement (TMVR) over transcatheter repair is the greater and more reliable reduction in mitral regurgitation. However, there are also potential disadvantages. This review introduces the newest TMVr and TMVR devices and presents clinical trial data to identify current challenges and directions for future research.

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.

Restructuring the Heart From Failure to Success: Role of Structural Interventions in the Realm of Heart Failure

Heart failure through the spectrum of reduced (HFrEF), mid-range (or mildly reduced or HFmEF), and preserved ejection fraction (HFpEF), continues to plague patients' quality of life through recurrent admissions and high mortality rates. Despite tremendous innovation in medical therapy, patients continue to experience refractory congestive symptoms due to adverse left ventricular remodeling, significant functional mitral regurgitation (FMR), and right-sided failure symptoms due to significant functional tricuspid regurgitation (FTR). As most of these patients are surgically challenging for open cardiac surgery, the past decade has seen the development and evolution of different percutaneous structural interventions targeted at improving FMR and FTR. There is renewed interest in the sphere of left ventricular restorative devices to effect reverse remodeling and thereby improve effective stroke volume and patient outcomes. For patients suffering from HFpEF, there is still a paucity of disease-modifying effective medical therapies, and these patients continue to have recurrent heart failure exacerbations due to impaired left ventricular relaxation and high filling pressures. Structural therapies involving the implantation of inter-atrial shunt devices to decrease left atrial pressure and the development of implantable devices in the pulmonary artery for real-time hemodynamic monitoring would help redefine treatment and outcomes for patients with HFpEF. Lastly, there is pre-clinical data supportive of soft robotic cardiac sleeves that serve to improve cardiac function, can assist contraction as well as relaxation of the heart, and have the potential to be customized for each patient. In this review, we focus on the role of structural interventions in heart failure as it stands in current clinical practice, evaluate the evidence amassed so far, and review promising structural therapies that may transform the future of heart failure management.

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.

Asymptomatic Stroke in the Setting of Percutaneous Non-Coronary Intervention Procedures

Advancements in clinical management, pharmacological therapy and interventional procedures have strongly improved the survival rate for cardiovascular diseases (CVDs). Nevertheless, the patients affected by CVDs are more often elderly and present several comorbidities such as atrial fibrillation, valvular heart disease, heart failure, and chronic coronary syndrome. Standard treatments are frequently not available for “frail patients”, in particular due to high surgical risk or drug interaction. In the past decades, novel less-invasive procedures such as transcatheter aortic valve implantation (TAVI), MitraClip or left atrial appendage occlusion have been proposed to treat CVD patients who are not candidates for standard procedures. These procedures have been confirmed to be effective and safe compared to conventional surgery, and symptomatic thromboembolic stroke represents a rare complication. However, while the peri-procedural risk of symptomatic stroke is low, several studies highlight the presence of a high number of silent ischemic brain lesions occurring mainly in areas with a low clinical impact. The silent brain damage could cause neuropsychological deficits or worse, a preexisting dementia, suggesting the need to systematically evaluate the impact of these procedures on neurological function.

Contemporary outcomes of mitral valve replacement in octogenarians

AIM OF THE STUDY

We aimed to determine the outcomes of contemporary mitral valve replacement (MVR) in octogenarians, for rational treatment selection in a patient cohort.

METHODS

Between 2007 and 2018, 656 consecutive MVRs were performed. Among these cases, 109 patients were aged 80 years or older, and 547 patients were younger than 80 years. Isolated MVRs were performed in 211 patients, of whom 36 were aged 80 years or older. Perioperative mortality and complications were compared between the two groups, adjusted by propensity score.

RESULTS

In-hospital mortality of the entire MVR (<80: 26 [4.8%] vs. ≥80: 6 [5.5%], p = .81) and isolated MVR (<80: 6 [3.4%] vs. ≥80: 1 [2.8%], p > .99) groups were similar. Age >80 years did not influence in-hospital mortality (hazard ratio [HR], 1.07; 95% confidence interval [CI], 0.36-3.14, p = .9), stroke (HR, 1.12; 95% CI, 0.19-6.71, p = .9), hemodialysis (HR, 1.44; 95% CI, 0.45-4.66, p = .54), or prolonged ventilation (HR, 1.61; 95% CI, 0.81-3.23, p = .18), but influenced the incidence of reopening for bleeding (HR, 3.97; 95% CI, 1.11-14.19, p = .03). Cox proportional hazard model results showed that age >80 years did not affect cardiac death (HR, 1.45, 95% CI: 0.67-3.12, p = .35), bleeding events (HR, 1.89, 95% CI: 0.84-4.27, p = .13), or stroke (HR, 1.51, 95% CI: 0.54-4.21, p = .44) during the follow-up period.

CONCLUSIONS

The perioperative and follow-up outcomes of MVR in octogenarians were not inferior to those of younger patients. We should not hesitate to conduct MVR on the grounds of old age.

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.

Imaging in Transcatheter Mitral Valve Replacement: State-of-Art Review

Mitral regurgitation is the second-most frequent valvular heart disease in Europe and it is associated with high morbidity and mortality. Recognition of MR should encourage the assessment of its etiology, severity, and mechanism in order to determine the best therapeutic approach. Mitral valve surgery constitutes the first-line therapy; however, transcatheter procedures have emerged as an alternative option to treat inoperable and high-risk surgical patients. In patients with suitable anatomy, the transcatheter edge-to-edge mitral leaflet repair is the most frequently applied procedure. In non-reparable patients, transcatheter mitral valve replacement (TMVR) has appeared as a promising intervention. Thus, currently TMVR represents a new treatment option for inoperable or high-risk patients with degenerated or failed bioprosthetic valves (valve-in-valve); failed repairs, (valve-in-ring); inoperable or high-risk patients with native mitral valve anatomy, or those with severe annular calcifications, or valve-in-mitral annular calcification. The patient selection requires multimodality imaging pre-procedural planning to select the best approach and device, study the anatomical landing zone and assess the risk of left ventricular outflow tract obstruction. In the present review, we aimed to highlight the main considerations for TMVR planning from an imaging perspective; before, during, and after TMVR.

Transcatheter treatment of tricuspid and mitral regurgitation. Similar path, different stages

Tricuspid regurgitation (TR) is frequently detected, especially in its secondary form, while primary TR is far less frequent. Similar to mitral regurgitation (MR), primary tricuspid regurgitation should require timely intervention to avoid secondary damage of the RV, which is associated with poor outcome. Current guidelines suggest that secondary TR should be treated at the time of left-sided valve surgery, although a surgical option is rarely offered to high-risk patients with combined heart valve disease. As such, while the transcatheter approach to mitral valve repair/replacement has become a major goal of the transcatheter therapies, the transcatheter tricuspid valve intervention is still at a very early stage. In this review, we provide an overview of the different stages of technical and clinical evolution of transcatheter treatment of patients with TR or MR, highlighting the challenges and the avenues for future research.

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.

1-Year Outcomes for Transcatheter Repair in Patients With Mitral Regurgitation From the CLASP Study

OBJECTIVES

The authors report the CLASP (Edwards PASCAL Transcatheter Mitral Valve Repair System Study) expanded experience, 1-year outcomes, and analysis by functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR).

BACKGROUND

The 30-day results from the CLASP study of the PASCAL transcatheter valve repair system for clinically significant mitral regurgitation (MR) have been previously reported.

METHODS

Eligible patients had symptomatic MR ≥3+, were receiving optimal medical therapy, and were deemed candidates for transcatheter mitral repair by the local heart team. Primary endpoints included procedural success, clinical success, and major adverse event rate at 30 days. Follow-up was continued to 1 year.

RESULTS

One hundred nine patients were treated (67% FMR, 33% DMR); the mean age was 75.5 years, and 57% were in New York Heart Association functional class III or IV. At 30 days, there was 1 cardiovascular death (0.9%), MR ≤1+ was achieved in 80% of patients (77% FMR, 86% DMR) and MR ≤2+ in 96% (96% FMR, 97% DMR), 88% of patients were in New York Heart Association functional class I or II, 6-min walk distance had improved by 28 m, and Kansas City Cardiomyopathy Questionnaire score had improved by 16 points (p < 0.001 for all). At 1 year, Kaplan-Meier survival was 92% (89% FMR 96% DMR) with 88% freedom from heart failure hospitalization (80% FMR, 100% DMR), MR was ≤1+ in 82% of patients (79% FMR, 86% DMR) and ≤2+ in 100% of patients, 88% of patients were in New York Heart Association functional class I or II, and Kansas City Cardiomyopathy Questionnaire score had improved by 14 points (p < 0.001 for all).

CONCLUSIONS

The PASCAL transcatheter valve repair system demonstrated a low complication rate and high survival, with robust sustained MR reduction accompanied by significant improvements in functional status and quality of life at 1 year. (The CLASP Study Edwards PASCAL Transcatheter Mitral Valve Repair System Study [CLASP]; NCT03170349).

Current Status of Catheter-based Mitral Valve Replacement

PURPOSE OF REVIEW

Transcatheter mitral valve replacement (TMVR) has been developed to address the need for an alternative therapeutic option to surgery in patients suffering from severe mitral regurgitation who are at high surgical risk. The present review illustrated the state-of-the-art of catheter-based mitral valve replacement evaluating technical characteristics and early clinical experience of different devices to outline prospects and challenges of TMVR.

RECENT FINDINGS

Several devices are currently under clinical assessment. Early experience has demonstrated high procedural success of TMVR. However, TMVR faces several possible hurdles such as left ventricular outflow tract obstruction (LVOTO) after prosthesis deployment, access site complications, and thrombotic risk requiring anticoagulatory therapy. Future studies should assess long-term prosthesis stability, optimal anticoagulation regime, and occurrence of paravalvular leakage. The development of smaller TMVR prostheses suitable for transseptal implantation could overcome bleeding complications. In perspective, TMVR may emerge to a clinically relevant therapeutic approach for patients with severe MR at high surgical risk.

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.

Mitral valve diseases: Pathophysiology and interventions

Valvular heart disease is common and increasingly prevalent among the elderly. The end result of valvular pathologies is cardiac failure and can lead to sudden death; thus, diagnosis and interventions are very important in the early stages of these diseases. The usual treatment methods of mitral regurgitation include percutaneous mitral valve repair, mitral valve replacement and minimally invasive surgery, whereas the treatment methods of mitral stenosis include percutaneous transluminal mitral commissurotomy and mitral commissurotomy as well as open surgical repair. Nonetheless, ongoing clinical trials are a clear indicator that the management of valve diseases is ever evolving. The focus of this paper is on the various pathologies of the mitral valve, their etiology and clinical management, offering a comprehensive view of mitral valve diseases.

Current and Future Application of Transcatheter Mitral Valve Replacement

Mitral valve anatomy is complex, and one size does not fit all. More recently, percutaneous mitral valve interventions have revolutionized the management of primary and secondary mitral regurgitation (MR). However, edge-to-edge leaflet repair is not suitable for a large proportion of individuals including those with a failing bioprosthetic mitral valve/annuloplasty ring, and patients with significant mitral annular calcification resulting in mixed mitral valve disease/mitral stenosis. For this high risk cohort, transcatheter mitral valve replacement seems to be an attractive alternative.

Transcatheter Mitral Valve Replacement: An Update on Current Techniques, Technologies, and Future Directions

Growing clinical data support the use of transcatheter therapies for significant mitral valve disease. Currently, edge-to-edge repair is the transcatheter treatment of choice, but many anatomies are not suitable. Transcatheter mitral valve replacement offers several potential advantages over transcatheter repair, most notably a greater and more sustained reduction in mitral regurgitation post-implantation, but also potential disadvantages. To enable the successful treatment of mitral valve disease in a wide range of patients and anatomies, we require an armory of transcatheter devices, including transcatheter mitral valve replacement systems.

Atrial and ventricular flows across a transcatheter mitral valve

 

OBJECTIVES

The objective of this study was to evaluate the haemodynamic performance of transcatheter mitral valve replacement (TMVR) Implant with a focus on turbulence and washout adjacent to the ventricular surface of the leaflets. TMVR holds the promise of treating a large spectrum of mitral valve diseases. However, the haemodynamic performance and flow dynamics of such replacements are not fully understood.

METHODS

A tri-leaflet biopsrosthetic TMVR represented by Caisson implant of size 36A was implanted in the mitral position of a left heart simulator pulse duplicating system under physiological conditions. The 36A implant covers an anterior-posterior range of 26-32 mm and a commissure-to-commissure range of 30-36 mm. Transmitral pressure gradient, effective orifice area and regurgitant fraction were calculated. Particle image velocimetry was performed to evaluate turbulence in 2 perpendicular planes (Reynolds and viscous shear stresses, respectively). Additionally, dye experiments were performed to visualize washout.

RESULTS

Transmitral pressure gradient was 1.29 ± 0.27 mmHg and effective orifice area was 2.96 ± 0.28 cm2. Regurgitant fraction was 14.13 ± 0.08%. Total washout was 4.27 cardiac cycles. Largest viscous shear stress reaches 3.7 Pa and 2.4 Pa in ventricle and atrium, respectively. Reynolds shear stress in the atrial side was <10 Pa. In the ventricular side, the largest Reynolds shear stress reached ∼35 Pa.

CONCLUSIONS

TMVR leads to favourable haemodynamics with low degree of turbulence combined with fast washout around the leaflets indicating promising potential for freedom from blood damage potential and thrombosis corroborated by initial clinical studies as part of the valves's Early Feasibility Study.

A step-by-step guide to transseptal valve-in-valve transcatheter mitral valve replacement

With the recent success of transcatheter aortic valve replacement (TAVR), transcatheter options for the management of mitral valve pathology have also gained considerable attention. Valve-in-valve (ViV) transcatheter mitral valve replacement (TMVR) is one such technique that has emerged as a safe and effective therapeutic option for patients with degenerated mitral valve bioprostheses at high-risk for repeat surgical mitral valve replacement. Several access strategies, including trans-apical, transseptal, trans-jugular, and trans-atrial access have been described for ViV-TMVR. Initial experiences were performed primarily via a trans-apical approach through a left mini-thoracotomy because it offers direct access and coaxial device alignment. With the advancements in TMVR technology, such as the development of smaller delivery catheters with high flexure capabilities, the transseptal approach via the femoral vein has emerged as the preferred option. This technique offers the advantages of a totally percutaneous approach, avoids the need to enter the thoracic cavity or pericardial space, and provides superior outcomes compared to a trans-apical approach. In this review, we outline key aspects of patient selection, imaging, procedural techniques, and examine contemporary clinical outcomes of transseptal ViV-TMVR.

Transcatheter mitral valve replacement: latest advances and future directions

Mitral regurgitation remains the most common form of valve disease worldwide and given an aging population with a significant proportion of secondary mitral regurgitation, a transcatheter approach to mitral valve replacement has become a major goal of the transcatheter therapeutics field. Mitral regurgitation can be caused by disease of the leaflets (primary) or by diseases of the left atrium or left ventricle (LV) (secondary or functional), and may involve overlap of the two (mixed disease). The location of the mitral valve (and large size), the approach to anchoring a valve replacement, and concerns about left ventricular outflow tract (LVOT) obstruction are all issues that have made the transcatheter delivery of a valve replacement challenging. Despite these challenges, both transapical and transseptal devices are currently being developed, with several in early feasibility trials and several entering pivotal trials. As the field of transcatheter mitral valve replacement (TMVR) improves and develops, a critical part of evaluating patients with mitral valve disease will be utilizing the heart team approach to identify and individualize the most appropriate treatment for each patient.

Current Devices in Mitral Valve Replacement and Their Potential Complications

Mitral regurgitation is one of the most prevalent valvulopathies worldwide, and its surgical treatment is not feasible in all cases. The elderly and frail with several comorbidities and left ventricular dysfunction are often managed conservatively. Percutaneous treatment (repair or replacement) of the mitral valve has emerged as a potential option for those patients who are at a high risk for surgery. Mitral valve repair with the Mitraclip device proved both increased safety and mortality reduction in patients with severe mitral regurgitation. On the other hand, in the last decade, percutaneous mitral replacement opened new frontiers in the field of cardiac structural interventions. There are few mitral devices; some are in the early phase of development and some are waiting for CE mark of approval. The evolution of these devices was more complicated compared to the aortic technology due to the native mitral valve's complexity and access. This review aims to provide an overview of the current devices, their specific features, and their potential complications.

Transcatheter mitral valve replacement

Transcatheter mitral valve (MV) repair, specifically the edge-to-edge leaflet repair, is a less invasive treatment of symptomatic mitral regurgitation (MR) in patients with high or prohibitive surgical risk. In cases with severe leaflet calcification, small mitral orifice area, and/or extremely wide regurgitation across the entire MV commissure, transcatheter MV repair may rather cause suboptimal or potentially hazardous outcomes. In these cases, MV replacement can be a more suitable option. Recently, percutaneous transcatheter MV replacement has emerged as an acceptable therapeutic option for the treatment of degenerated surgical bioprosthetic disease. Moreover, several transcatheter devices for native MV replacement are under evaluation with a hope to provide more complete and reproducible restoration of MV function. In this article, we will review current status, applications, clinical outcomes, and limitations that need to be overcome for transcatheter MV replacement for both degenerated surgical bioprosthetic disease and native MV disorders.

Transcatheter Mitral Valve Replacement: Rationale and Current Status

Mitral regurgitation (MR) is the most prevalent form of moderate or severe valve disease in the developed world. MR can result from impairment of any part of the mitral valve apparatus and is classified as primary (disease of the leaflets) or secondary (functional). The presence of at least moderate MR is associated with increased morbidity and mortality. With the goal of avoiding the risks of traditional surgery, transcatheter mitral valve therapies have been developed. The current transcatheter repair techniques are limited by therapeutic target and incomplete MR reduction, and thus transcatheter mitral valve replacement (TMVR) has been pursued. Several devices (both transapical and transseptal) are under development, with both early feasibility and pivotal trials under way. As this field develops, the decision to treat with TMVR will require a heart team approach that takes patient-, disease-, and device-specific factors into account.