Mitral loop cerclage as a variant form of mitral cerclage annuloplasty that adds a device (CSTV) for preventing potential complications: a preclinical proof of concept and feasibility study

Over 15 years: the advancement of transcatheter mitral valve repair

Patients with severe symptomatic mitral regurgitation, if left untreated, have a poor prognosis. In those patients not eligible for mitral valve (MV) surgery, percutaneous repair may improve clinical outcomes. In the past 15 years several devices have been developed to address different MV lesions. This manuscript will review the advancement of transcatheter MV repair through the years, focusing on technologies for which consistent clinical data is available.

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.

Emerging Technologies for Percutaneous Mitral Valve Repair

Mitral regurgitation (MR) is a common disease affecting more than 4 million people in the United States and the European Union. A significant number of percutaneous valves have been developed recently, specifically designed for the mitral anatomy, and with a promising evidence of good procedural and echocardiographic outcomes. However, even if transcatheter mitral valve replacement (TMVR) will have a role in the future of percutaneous treatment of both functional and degenerative mitral regurgitation, percutaneous mitral valve repair will always play a vital role in the treatment of MR because of the favorable safety profile and the fact that it respects the native anatomy. In this review, we will discuss the new emerging technologies under development to treat mitral regurgitation focusing on different devices that aim to target different components of the mitral anatomy.

Transcatheter Valve Replacement in Asia Pacific: Current Practice and Perspectives

Although the field of transcatheter therapies for valvular heart disease (VHD) is continuously expanding in western countries, uptake of this treatment in Asia has been slow, mainly due to the high cost of devices, need for specific training programs, and lack of specialized heart teams and dedicated structures. Moreover, anatomic considerations of the Asian population, such as smaller aorta and peripheral vessel size, high prevalence of bicuspid aortic valves, high calcium burden of stenotic aortic valve leaflets, low coronary ostia, and high prevalence of rheumatic etiology, might raise concerns about feasibility, risk of procedural complications, prosthesis durability, and long-term outcomes after transcatheter treatment of VHD. Asia Pacific and China's medical communities and manufacturer companies are setting up to address this unmet clinical need. The aim of this review is to summarize the landscape of currently available devices for transcatheter valve interventions and the clinical experience to date in China and Asian Pacific countries, with a specific focus on new, locally designed, and/or manufactured devices.

Update on the Current Landscape of Transcatheter Options for Tricuspid Regurgitation Treatment

Most patients with severe tricuspid regurgitation lack treatment options because of prohibitive surgical risk. New transcatheter treatments under development and investigation might be able to address this unmet clinical need. This article gives an update on the landscape of devices for transcatheter tricuspid regurgitation treatment including different approaches (i.e. repair with leaflet approximation or annuloplasty and replacement using orthotopic or heterotopic valves) at different stages of development, from experimental to clinical trial. Repair devices such as the Cardioband or the MitraClip are leading the field with promising preliminary data and further trials are ongoing. However, with implantations of the Gate bioprosthesis, replacement devices are catching up. Potential advantages of different approaches and most recent data are discussed.

Computational analysis of the electromechanical performance of mitral valve cerclage annuloplasty using a patient-specific ventricular model

We aimed to propose a novel computational approach to predict the electromechanical performance of pre- and post-mitral valve cerclage annuloplasty (MVCA). Furthermore, we tested a virtual estimation method to optimize the left ventricular basement tightening scheme using a pre-MVCA computer model. The present model combines the three-dimensional (3D) electromechanics of the ventricles with the vascular hemodynamics implemented in a lumped parameter model. 3D models of pre- and post-MVCA were reconstructed from the computed tomography (CT) images of two patients and simulated by solving the electromechanical-governing equations with the finite element method. Computed results indicate that reduction of the dilated heart chambers volume (reverse remodeling) appears to be dependent on ventricular stress distribution. Reduced ventricular stresses in the basement after MVCA treatment were observed in the patients who showed reverse remodeling of heart during follow up over 6 months. In the case who failed to show reverse remodeling after MVCA, more virtual tightening of the ventricular basement diameter than the actual model can induce stress unloading, aiding in heart recovery. The simulation result that virtual tightening of the ventricular basement resulted in a marked increase of myocardial stress unloading provides in silico evidence for a functional impact of MVCA treatment on cardiac mechanics and post-operative heart recovery. This technique contributes to establishing a pre-operative virtual rehearsal procedure before MVCA treatment by using patient-specific cardiac electromechanical modeling of pre-MVCA.

Mitral Loop Cerclage Annuloplasty for Secondary Mitral Regurgitation: First Human Results

OBJECTIVES

This is an early feasibility clinical test of mitral loop cerclage annuloplasty to treat secondary mitral valve regurgitation.

BACKGROUND

Secondary mitral regurgitation is characterized by cardiomyopathy, mitral annular enlargement, and leaflet traction contributing to malcoaptation. Transcatheter mitral loop cerclage applies circumferential compression to the mitral annulus by creating a loop through the coronary sinus across the interventricular septum, protecting entrapped coronary arteries from compression, and interactive annular reduction under echocardiographic guidance. This is the first human test of mitral loop annuloplasty.

METHODS

Five subjects with severe symptomatic secondary mitral regurgitation underwent mitral loop cerclage, with echocardiographic and computed tomography follow-up over 6 months.

RESULTS

Mitral loop cerclage was successful in 4 of 5 subjects and aborted in 1 of the 5 because of unsuitable septal coronary vein anatomy. Immediately and over 6 months, measures of both mitral valve regurgitation (effective orifice area and regurgitation fraction) and chamber dimensions (left atrial and left ventricular volumes) were reduced progressively and ejection fractions increased. Two with persistent and permanent atrial fibrillation spontaneously reverted to sinus rhythm during follow-up. One subject experienced a small myocardial infarction from an unrecognized small branch coronary occlusion. Another, experiencing cardiogenic shock at baseline, died of intractable heart failure after 6 weeks.

CONCLUSIONS

In this first human test, mitral loop cerclage annuloplasty was successful in 4 of 5 attempts, caused reverse remodeling (reduction in secondary mitral regurgitation and heart chamber volumes), and suggested electrical remodeling (reversion of atrial fibrillation). Further evaluation is warranted.