Short- and mid-term outcomes in percutaneous mitral valve replacement using balloon expandable valves

Rheumatic and Degenerative Mitral Stenosis: From an Iconic Clinical Case to the Literature Review

Mitral stenosis (MS) poses significant challenges in diagnosis and management due to its varied etiologies, such as rheumatic mitral stenosis (RMS) and degenerative mitral stenosis (DMS). While rheumatic fever-induced RMS has declined in prevalence, DMS is rising with aging populations and comorbidities. Starting from a complex clinical case of DMS, the aim of this paper is to review the literature on mitral stenosis by analyzing the available tools and the differences in terms of diagnosis and treatment for rheumatic and degenerative stenosis. Emerging transcatheter techniques, such as transcatheter mitral valve replacement (TMVR) and lithotripsy-facilitated percutaneous mitral commissurotomy (PMC), represent promising alternatives for DMS patients deemed unfit for surgery. In particular, intravascular lithotripsy (IVL) has shown potential in facilitating percutaneous interventions by fracturing calcific deposits and enabling subsequent interventions. However, larger prospective studies are warranted to validate these findings and establish IVL's role in DMS management. To further enhance this technique, research could focus on investigating the long-term outcomes and durability of mitral lithotripsy, as well as exploring its potential in combination with PMC or TMVR.

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.

Postsurgical Transcatheter Mitral Valve Replacement

Reintervention is commonly required postsurgical mitral valve replacement (SMVR) or repair due to bioprosthetic valve and annuloplasty ring degeneration. However, redo SMVR is associated with a high risk of morbidity and mortality. Postsurgical transcatheter mitral valve replacement (TMVR) is a safe and less-invasive alternative that has repeatedly been shown to be associated with improved survival and lower rates of complications compared with redo SMVR. Comprehensive patient evaluation and thorough procedural planning are key to successful TMVR.

The 40th Anniversary of Percutaneous Balloon Valvuloplasty for Mitral Stenosis: Current Status

Percutaneous balloon mitral valvuloplasty (PBMV), once the most complex of percutaneous cardiac procedures and essentially the first adult structural heart intervention, set the stage for a host of new technologies. Randomized studies comparing PBMV to surgery were the first to provide a high-level evidence base in structural heart. The devices used have changed little in 40 years, but the advent of improved imaging and the expertise gained in interventional cardiology has provided some additional procedural safety. However, with the decline in rheumatic heart disease, PBMV is being performed in fewer patients in industrialized nations; in turn, these patients have more comorbidities, less favorable anatomy, and thus a higher rate of procedure-related complications. There remain relatively few experienced operators, and the procedure is distinct enough from the rest of the structural heart intervention world that it has its own steep learning curve. This article reviews the use of PBMV in a variety of clinical settings, the influence of anatomic and physiologic factors on outcomes, the changes in the guidelines, and alternative approaches. PBMV remains the procedure of choice in patients with mitral stenosis with ideal anatomy and a useful tool in patients with less than ideal anatomy who are poor surgical candidates. In the 40 years since its first performance, PBMV has revolutionized the care of mitral stenosis patients in developing countries and remains an important option for suitable patients in industrialized nations.

Transcatheter Mitral Valve Replacement in Failed Bioprosthetic Surgical Valves and Surgical Annuloplasty Rings

PURPOSE OF REVIEW

Repeat surgery for failed mitral valve prostheses and repairs are fraught with high rates of morbidity and mortality. Therefore, clinicians have evolved transcatheter technology as an alternative therapy. This review serves as an update as the field has moved out of the early learning curve of treating postsurgical mitral valve failures.

RECENT FINDINGS

Mitral valve-in-valve procedures have higher rates of technical success and better in-hospital and 1-year mortality rates than mitral valve-in-ring cases. The higher rates of complications, including left ventricular outflow tract obstruction, paravalvular leak, valve embolization, and need for a 2nd valve, may explain these outcomes. Mitral valve-in-ring procedures have attenuated outcomes as compared to valve-in-valve. Clinicians should be cognizant of the nuanced complexities and the potential for suboptimal outcomes in using balloon-expandable valves for mitral valve-in-ring procedures.