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.

Management of life-threatening deformation of obstructive transcatheter mitral valve replacement bioprosthesis with balloon inflation in left ventricular outflow tract: a case report.

Background: Left ventricular outflow track (LVOT) obstruction (LVOTO) is a severe complication of transcatheter mitral valve replacement (TMVR) procedures, with an uncertain prognosis and only few strategies available to prevent its occurrence. TMVR is thus contraindicated in some patients because of a high risk of LVOTO onset. We demonstrate how LVOTO can be managed with a balloon inflation in the LVOT and a D-shaped deformation of the bioprosthetic valve. Case summary: A 64-year-old female presented with acute pulmonary oedema 2 weeks following aortic valve replacement and aorto-coronary bypass surgeries. A concomitant mitral stenosis, secondary to significant calcifications of the mitral annulus, was not treated during the procedure. After surgery, the mitral valvulopathy caused an acute heart failure and TMVR was performed by the heart team. The procedure was complicated by a cardiac arrest secondary to the onset of LVOTO which was managed by a balloon inflation in the LVOT and an alcohol septal ablation. Two-year follow-up shows a favourable outcome of the patient and good function of the prosthetic valve despite its deformation. Discussion: This case highlights the successful management of a LVOTO following valve-in-mitral annular calcification TMVR by balloon inflation in the LVOT. It is strongly recommended to place a 'rescue' guidewire in transaortic position during TMVR in order to manage the potential onset of acute LVOTO.

Management of Patients With Severe Mitral Annular Calcification: JACC State-of-the-Art Review.

Mitral annular calcification (MAC) is a common and challenging pathologic condition, especially in the context of an aging society. Surgical mitral valve intervention in patients with MAC is difficult, with varying approaches to the calcified annular anatomy, and the advent of transcatheter valve interventions has provided additional treatment options. Advanced imaging provides the foundation for heart team discussions and management decisions concerning individual patients. This review focuses on the prognosis of, preoperative planning for, and management strategies for patients with MAC.

Transcatheter mitral valve replacement for degenerated mitral valve bioprostheses, failure of mitral valvuloplasty and native valve with severe mitral annulus calcification: a systematic review and meta-analysis.

BACKGROUND: Although transcatheter technology has achieved some success in the field of mitral valves, the feasibility of applying it to patients with degenerated mitral valve bioprostheses (valve-in-valve, ViV), failure of mitral valvuloplasty (valve-in-ring, ViR) and serious mitral annulus calcification (vale-in-MAC, ViMAC) has not been effectively evaluated. METHODS: By searching published literature before December 5, 2020 in four databases, we found all the literature related to the evaluation of feasibility assessment of TMViV, TMViR and TMViMAC. Outcomes focused on all-cause mortality within 30 days, bleeding and LVOT obstruction. RESULTS: A total of six studies were included, and all of them were followed up for at least 30 days. After analysis of the ViV-ViR group, we obtained the following results: the all-cause mortality within 30 days of the ViV group was lower than that of the ViR group. Life-threatening or fatal bleeding was more likely to occur in the ViR group after surgery. At the same time, the ViR group was more prone to left ventricular outflow tract obstruction. However, in the ViMAC-ViR group, only the all-cause mortality within 30 days and stroke were statistically significant. In the indirect comparison, we found that TMViV had the best applicability, followed by TMViR. There were few TMViMAC available for analysis, and it requires further studies to improve the accuracy of the results. CONCLUSION: TMViV and TMViR had good applicability and could benefit patients who underwent repeat valve surgery. The feasibility of TMViMAC needs to be further explored and improved.

Multimodality Cardiac Imaging for Procedural Planning and Guidance of Transcatheter Mitral Valve Replacement and Mitral Paravalvular Leak Closure.

Transcatheter mitral valve interventions are an evolving and growing field in which multimodality cardiac imaging is essential for diagnosis, procedural planning, and intraprocedural guidance. Currently, transcatheter mitral valve-in-valve with a balloon-expandable valve is the only form of transcatheter mitral valve replacement (TMVR) approved by the FDA, but valve-in-ring and valve-in-mitral annular calcification interventions are increasingly being performed. Additionally, there are several devices under investigation for implantation in a native annulus. Paravalvular leak (PVL) is a known complication of surgical or transcatheter valve implantation, where regurgitant flow occurs between the prosthetic sewing ring and the native mitral annulus. We sought to describe the role and applications of multimodality cardiac imaging for TMVR, and PVL closure, including the use of Cardiovascular Computed Tomography Angiography and 3-Dimensional Transesophageal Echocardiography for diagnosis, prosthetic valve evaluation, pre-procedural planning, and intraprocedural guidance, as well as evolving technologies such as fusion imaging and 3D printing.

Challenges and Open Issues in Transcatheter Mitral Valve Implantation: Smooth Seas Do Not Make Skillful Sailors.

According to the European and American guidelines, surgery represents the treatment of choice for mitral valve (MV) disease. However, a number of patients are deemed unsuitable for surgery due to a prohibitive/high operative risk. In such cases, transcatheter therapies aiming at MV repair have been proven to be a valuable alternative and have been recently introduced in the latest American guidelines on valvular heart disease. Indeed, percutaneous repair techniques, particularly transcatheter edge-to-edge, have gained a broad experience and demonstrated to be safe and effective. However, given the complexity and heterogeneity of MV anatomy and pathology, transcatheter MV implantation (TMVI) has grown as a possible alternative to percutaneous MV repair. Current data about TMVI are still limited and come from different settings: valve-in-native MV, valve-in-valve (ViV), valve-in-ring (ViR), and valve-in-mitral annular calcification. Preliminary data are promising although several open issues still need to be addressed. This paper provides a comprehensive review of the available devices in the different clinical settings, to discuss potentialities, limitations, and future directions for TMVI.

Long or redundant leaflet complicating transcatheter mitral valve replacement: Case vignettes that advocate for removal or reduction of the anterior mitral leaflet.

Transcatheter mitral valve replacement (TMVR) procedures can be an alternative to surgical valve replacement for high surgical risk patients with bioprosthetic mitral valves, annuloplasty rings, or severe mitral annular calcification (MAC). TMVR can trigger acute left ventricular outflow tract (LVOT) obstruction from permanent displacement of the native anterior mitral leaflet toward the left ventricular septum, more often among patients undergoing valve-in-ring and valve-in-MAC procedures. Although acute LVOT obstruction is well described in the literature, there are important additional complications of TMVR related to the length and/or redundancy of the anterior mitral valve that have been recognized after mitral valve surgery and have not been previously reported in the setting of TMVR. These additional complications include acute mitral regurgitation secondary to prolapsing native leaflet through the TMVR, frozen TMVR leaflet secondary to overhanging native leaflet and late LVOT obstruction in the neo-LVOT secondary to long native leaflet. Preprocedural planning with imaging (echocardiography and computed tomography) and measurement of anterior mitral leaflet length is critical important in understanding the risk for these complications. As transcatheter mitral valve technology proliferates, interactions with the anterior mitral leaflet after TMVR may be more frequent than initially anticipated. We believe that there is no advantage to an intact anterior leaflet and advocate removal or reduction of the leaflet prior to TMVR. © 2017 Wiley Periodicals, Inc.