Transcatheter mitral valve replacement: latest advances and future directions

From Repair to Replacement: Ring Detachment and Secondary Annular Injury During Transcatheter Mitral Valve-in-Ring Procedure

OBJECTIVE

The present case portrays an infrequent complication of transcatheter mitral valve replacement (TMVR) in a patient with a previous surgical mitral valve repair with ring annuloplasty and an Alfieri stitch, who developed mitral stenosis and heart failure.

KEY STEPS

After transseptal puncture, balloon atrial septostomy and mitral balloon valvuloplasty were performed. The transcatheter valve was positioned and deployed through a partial dehiscence on the anterior aspect of the prosthetic ring, probably caused by the balloon valvuloplasty or undetected in the preprocedural imaging assessment. This led to prosthetic ring detachment and dislocation, native annular tearing, migration of the transcatheter prosthesis, and subsequent hemodynamic collapse requiring open surgery.

POTENTIAL PITFALLS

In TMVR, prosthesis misalignment or malposition may cause annular stress during deployment and tearing of the native annulus, prosthesis embolization from suboptimal anchoring, and cardiac tamponade from left ventricular rupture, often requiring emergency surgical intervention.

Transcatheter mitral valve replacement to treat rheumatic mitral stenosis: a case series

Background

Rheumatic mitral stenosis (RMS) is a common valvular heart disease in developing countries. We sought to evaluate the early experience of patients with RMS undergoing transcatheter mitral valve replacement (TMVR).

Methods

In this retrospective study, a total of 5 RMS patients accepted TMVR. All patients underwent computed tomography and echocardiography before having the procedure. After the preprocedural comprehensive evaluations, the surgeons planned to use the Prizvalve (a novel balloon-expandable transcatheter aortic valve system which is now under the clinical registration study) for TMVR. Clinical data were collected at baseline, before discharge, and at the 30-day follow-up.

Results

The median age of the 5 RMS patients was 61 years (range 60-77 years); 60% were male, and the median Society of Thoracic Surgeons score was 13.3% (range 6.2-17.1%). TMVR was successful in all patients. Postoperative transesophageal echocardiography showed that 60.0% (n = 3) of the patients had no paravalvular leakage and 40.0% (n = 2) had trace paravalvular leakage. The median postoperative peak velocity decreased to 1.4 m/s (range 1.1-1.7 m/s), and the median pressure gradient decreased to 3 mmHg (range 2-3 mmHg). No deaths occurred at the 30-day follow-up, and all patients had an improvement of ≥1 on the New York Heart Association functional rating.

Conclusions

Our early experience with TMVR in RMS patients suggests that it is a safe and feasible procedure. The early results of the procedure are acceptable and provide bright prospects and directions for the precision treatment of RMS.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT02917980).

Circumflex Coronary Artery Injury during Modern Mitral Valve Surgery-A Review of Current Concepts and Perspectives

The devastating impact of a circumflex coronary artery (CX) injury during mitral valve (MV) surgery is well reported. Despite significant improvements in preoperative risk assessment, intraoperative diagnosis and perioperative treatment strategies of CX injury during MV surgery, recent reports re-emphasize the variability in presentation, the unpredictable mechanisms of injury and the conflicting evidence regarding perioperative management. The progressive transition from conventional sternotomy access to minimally invasive surgical and transcatheter (TC) interventions for MV disease are associated with significant learning curves and require additional single-shaft and robotic console suture manipulation skills with special attentiveness to the potential risk of CX injury. The introduction of hybrid theatres that facilitate single stage surgical and TC interventions also provides new intraoperative diagnostic and therapeutic options without transporting unstable patients for percutaneous coronary intervention (PCI) assessment. By utilizing a MeSH terms-based PubMed search, a total of 89 patients with CX injury that occurred during MV surgery was identified from 49 reports between 1967 and 2022. MV surgery was performed by conventional sternotomy (n = 76, 85.4%), endoscopic (n = 12, 13.4%) and robotic access (n = 1, 1.1%), with 35 injuries (39.3%) resulting in total CX occlusion. Rescue PCI was utilized in 40 patients (44.9%). This manuscript provides a systematic overview of all available historic and contemporary reports on CX injury during MV surgery, outlines recent refinements in CX injury mechanisms, describes current MV surgery associated CX injury prevention and diagnosis and treatment strategies and highlights important MV procedural aspects that may minimize the risk and consequences of CX injury.

New Perspective on Pathophysiology and Management of Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) occurs as a result of global or segmental left ventricular (LV) dysfunction or left atrial dilatation, leading to mitral annular dilatation, papillary muscle displacement, mitral valve (MV) leaflet tethering, and leaflet remodeling. The prevalence of FMR continues to rise in the United States. Even mild FMR is associated with adverse clinical outcomes. Echocardiography is the primary imaging modality used to assess the type and severity of mitral regurgitation. FMR treatment depends on the etiology. Evidence-based pharmacologic and cardiac resynchronization therapies for underlying LV dysfunction remain the mainstay of treatment. Patients who remain symptomatic despite optimal medical therapy can be considered for surgical or percutaneous MV intervention. This article reviews the pathophysiology, imaging evaluation, and therapeutic options of FMR, highlighting the most recent developments in a rapidly evolving field.

Transcatheter Interventions in Patients With Adult Congenital Heart Disease

Patients with congenital heart disease now live well into adulthood because of advances in surgical techniques, improvements in medical management, and the development of novel therapeutic agents. As patients grow older into adults with congenital heart disease, many require catheter-based interventions for the treatment of residual defects, sequelae of their initial repair or palliation, or acquired heart disease. The past 3 decades have witnessed an exponential growth in both the type and number of transcatheter interventions in patients with congenital heart disease. With improvements in medical technology and device design, including the use of devices designed for the treatment of acquired valve stenosis or regurgitation, patients who previously would have required open-heart surgery for various conditions can now undergo percutaneous cardiac catheter-based procedures. Many of these procedures are complex and occur in complex patients who are best served by a multidisciplinary team. This review aims to highlight some of the currently available transcatheter interventional procedures for adults with congenital heart disease, the clinical outcomes of each intervention, and any special considerations so that the reader may better understand both the procedure and patients with adult congenital heart disease.

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.

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.

Transcatheter Mitral Valve Therapy in the United States: A Report From the STS-ACC TVT Registry

Data for nearly all patients undergoing transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) with an approved device in the United States is captured in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. All data submitted for TEER or TMVR between 2014 and March 31, 2020, are reported. A total of 37,475 patients underwent a mitral transcatheter procedure, including 33,878 TEER and 3,597 TMVR. Annual procedure volumes for TEER have increased from 1,152 per year in 2014 to 10,460 per year in 2019 at 403 sites and for TMVR from 84 per year to 1,120 per year at 301 centers. Mortality rates have decreased for TEER at 30 days (5.6%-4.1%) and 1 year (27.4%-22.0%). Early off-label use data on TMVR in mitral valve-in-valve therapy led to approval by the U.S. Food and Drug Administration in 2017, and the 2019 30-day mortality rate was 3.9%. Overall improvements in outcomes over the last 6 years are apparent. (STS/ACC TVT Registry Mitral Module; NCT02245763).

Transcatheter Mitral Valve Therapy in the United States: A Report from the STS/ACC TVT Registry

Data for nearly all patients undergoing transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) with an approved device in the United States is captured in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. All data submitted for TEER or TMVR between 2014 and March 31, 2020, are reported. A total of 37,475 patients underwent a mitral transcatheter procedure, including 33,878 TEER and 3,597 TMVR. Annual procedure volumes for TEER have increased from 1,152 per year in 2014 to 10,460 per year in 2019 at 403 sites and for TMVR from 84 per year to 1,120 per year at 301 centers. Mortality rates have decreased for TEER at 30 days (5.6%-4.1%) and 1 year (27.4%-22.0%). Early off-label use data on TMVR in mitral valve-in-valve therapy led to approval by the U.S. Food and Drug Administration in 2017, and the 2019 30-day mortality rate was 3.9%. Overall improvements in outcomes over the last 6 years are apparent. (STS/ACC TVT Registry Mitral Module; NCT02245763).

Transcatheter mitral valve therapies: State of the art

Mitral regurgitation (MR) is one of the most prevalent valvular pathologies in the developed world. There continues to be a growing population of aging patients with MR who may be too high risk for surgical management. The rapid adoption and remarkable success of transcatheter aortic valve replacement (TAVR) generated enthusiasm for transcatheter mitral valve therapies; however, the complex anatomy and pathophysiology of the mitral valve confers several unique challenges for a fully percutaneous approach. Nevertheless, several devices are under development and in various phases of preclinical or clinical testing, both for transcatheter mitral valve replacement and repair. MitraClip (Abbott Vascular), which has received FDA approval, is the most established percutaneous repair strategy and has been performed in over 80,000 patients as of 2019. The following article serves as a review of the available and upcoming devices for the various etiologies of mitral valvular disease, as well as the unique challenges and potential complications of transcatheter mitral valve intervention.

Transcatheter mitral valve interventions: pre-procedural planning and intra-procedural guidance

Mitral regurgitation is the most prevalent valve disease worldwide. Percutaneous mitral valve interventions are emerging as alternative options for high-risk patients with severe mitral regurgitation not eligible for conventional surgery. Accurate patient selection is based on a detailed pre-procedural multimodality imaging evaluation. Morphology and functional anatomy of the mitral valve should be evaluated to determine the feasibility of treatments and to identify the best therapeutic approach. The procedures are guided by fluoroscopy, transoesophageal echocardiography and fusion imaging, ensuring a continuous communication between the interventionalist and the imaging specialist. The present review will cover the pre-procedural planning and the intra-procedural guidance of the most used transcatheter approaches in the setting of native mitral valve regurgitation: edge to edge repair, percutaneous direct and indirect annuloplasty, transapical beating-heart chordal implantation and transcatheter mitral valve replacement.