Current Status and Future Prospects of Transcatheter Mitral Valve Replacement: JACC State-of-the-Art Review

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.

Evaluating the AltaValve as a novel method for transcatheter mitral valve replacement

Mitral regurgitation (MR) is the most common heart valve disease, and severe MR is associated with a poor prognosis if left untreated. Although surgical repair or replacement constitutes the standard therapy when indicated, many high-risk patients are considered ineligible for surgery. Transcatheter mitral valve replacement (TMVR) offers a less invasive alternative to conventional surgery and may also overcome some of the limitations of percutaneous repair techniques. Currently, multiple TMVR devices are undergoing clinical evaluation, showing promising results. However, challenges mainly related to the complex mitral valve anatomy along with the interaction with the left ventricular outflow tract (LVOT) have resulted in high screen failure rates among TMVR candidates. The AltaValve System features a supra-annular design, ensuring secure fixation in the left atrium above the native mitral valve annulus without anchoring mechanisms that could interfere with the left ventricle (LV). These distinctive attributes aim to address the existing TMVR limitations across a broad patient population and help to avoid complications such as LVOT obstruction, LV damage, and/or prosthesis embolization. Initial safety and feasibility data are encouraging, but a larger cohort of patients with longer follow-up will be essential to confirm the safety and efficacy of the AltaValve system.

Lithotripsy-Facilitated or Conventional Percutaneous Mitral Balloon Valvuloplasty for Calcific Mitral Valve Disease: A Systematic Review

Background

The efficacy of percutaneous mitral balloon valvuloplasty (PMBV) for mitral stenosis (MS) secondary to mitral annular calcification (MAC) is poorly understood. The purpose of this systematic review was to consolidate existing data on conventional and lithotripsy-facilitated PMBV in patients with calcific mitral valve disease, to better understand procedural outcomes.

Methods

We performed a systematic search of the literature published in PubMed and Scopus databases through May 2024. We included all studies that reported outcomes of conventional PMBV as a standalone therapy or lithotripsy-facilitated mitral intervention for calcific mitral valve disease.

Results

A total of 12 reports met the criteria for inclusion (8 lithotripsy and 4 conventional PMBV), including 4 case series and 8 case reports. Conventional PMBV (n = 44) procedural success in MAC was variable and associated with a limited reduction in mitral gradient in most patients. After conventional PMBV, 4 (9.1%) patients had moderate-to-severe mitral regurgitation (MR) or more, and 6 (13.6%) required mitral re-intervention. On the contrary, lithotripsy-facilitated PMBV for MAC (n = 40) led to hemodynamic improvement in most cases with a mean reduction of 5 to 8 mm Hg in mean mitral gradient. One case (2.5%) developed increased MR from baseline, and 1 (2.5%) required mitral reintervention. Outcomes beyond 3 months were lacking and precluded assessment on whether these improvements are sustained.

Conclusions

This systematic review suggests that lithotripsy-facilitated PMBV for MAC-related MS is feasible and may offer favorable short-term outcomes compared with conventional PMBV alone. These findings highlight the need for larger, multicenter studies with longer follow-up.

Interventions for adult congenital heart disease

Advances in imaging diagnostics, surgical techniques and transcatheter interventions for paediatric patients with severe congenital heart disease (CHD) have substantially reduced mortality, thereby extending the lifespan of these individuals and increasing the number of adults with complex CHD. Transcatheter interventions have emerged as an alternative to traditional open-heart surgery to mitigate congenital defects. The evolution of techniques, the introduction of new devices and the growing experience of operators have enabled the treatment of patients with progressively more complex conditions. The general cardiology community might be less aware of contemporary interventions for adult CHD, their clinical indications and associated outcomes than interventional cardiologists and congenital heart specialists. In this Review, we provide a comprehensive evaluation of the available transcatheter interventions for adult patients with CHD.

Transcatheter Approaches to Atrial Functional Mitral Regurgitation: How Far Have We Come?

Functional mitral regurgitation (MR) is associated with increased cardiovascular morbidity and mortality and over the past decade, the diagnosis of atrial functional mitral regurgitation (aFMR) has been increasingly observed in the elderly, especially in those with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). Annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering distinguish the pathophysiology of aFMR from the one of ventricular origin. However, no consensus provides recommendations regarding the differential diagnosis and the subsequent management of aFMR. The advent of transcatheter mitral valve repair has paved the way for various treatments including edge-to-edge repair (TEER), mitral annuloplasty, and replacement, with optimistic results on short-medium-term outcome provided by preliminary studies. In parallel, rhythm control of AF for paroxysmal and persistent types, should be pursued to induce reverse remodeling and restoring the normal leaflet coaptation. In this setting, catheter ablation aiming for electrical isolation of the pulmonary veins is the most widely recognized and effective strategy for maintaining sinus rhythm. Nevertheless, arrhythmia-free survival is lower in patients with persistent and long-term persistent AF, leading to the adoption of hybrid strategies combining transcatheter endocardial ablation and thoracoscopic epicardial surgical ablation. This review provides an update on the diagnosis and treatment of aFMR, focusing on available transcatheter approaches that can be performed in the catheterization lab and electrophysiology lab.

Early Feasibility Study with the SATURN Transapical Mitral Valve Replacement Device

Purpose

To report the outcomes of the early feasibility study of transapical transcatheter mitral valve replacement (TMVR) with the SATURN System (InnovHeart, Milano, Italy) to treat patients with severe functional mitral regurgitation.

Description

Five high surgical risk patients underwent transapical transcatheter mitral valve replacement with the SATURN System at a single center. One-year follow-up is complete for all patients.

Evaluation

The valve was implanted successfully in all patients without any major adverse events. All patients were alive at the last follow-up. Kansas City Cardiomyopathy Questionnaire improved from a median of 63.5 (interquartile range, 19.6) at baseline to 99.0 (interquartile range, 21.6) at 1 year. Echocardiographic follow-up demonstrates stable valve function, no transvalvular or paravalvular mitral regurgitation, and absence of left ventricular outflow tract obstruction.

Conclusions

At 1 year after transapical SATURN transcatheter mitral valve replacement, all patients are alive with quality of life improvement and favorable device hemodynamics. These initial results are promising and larger scale studies with continued follow-up are required to further elucidate the efficacy and safety of this novel technology.

Structural Cardiac Interventions in Patients With Heart Failure: JACC Scientific Statement

Pathologic left ventricular remodeling and valvular heart disease may contribute to the clinical presentation and outcomes of patients presenting with heart failure, and limit the effectiveness of guideline-directed medical therapy. Although surgical interventions including surgical ventricular restoration techniques and valve repair or replacement are effective therapies, there is growing evidence that transcatheter interventions may be options for patients with persistent symptoms of heart failure despite optimal medical therapy, where surgical options may be limited. This scientific statement will review the current available and investigational percutaneous strategies for the management of structural contributors to heart failure: dilated left ventricular cardiomyopathies and valvular heart disease.

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.

Management strategies and prognosis of patients ineligible for transcatheter mitral valve replacement

BACKGROUND

Transcatheter mitral valve replacement (TMVR) faces anatomical challenges, currently limiting widespread adoption.

OBJECTIVES

To describe the natural history and prognosis of patients ineligible for various TMVR devices.

METHODS

During a 4-year period (2019-2023) 3 TMVR devices (SAPIEN M3, Intrepid and Alta Valve) became available at a single institution (The Christ Hospital, Cincinnati, OH) in the setting of pivotal clinical trials or early feasibility study. Consenting patients who were deemed ineligible ≥1 of these trials were prospectively studied to capture anatomical reasons for ineligibility, cross-over to alternative mitral valve therapies (surgery or high-risk mitral transcatheter edge to edge repair [M-TEER]), and clinical events.

RESULTS

A total of 61 patients (out of 71 consenting patients or 85.9 %) were deemed ineligible for TMVR during the study period. The mean age was 79.2 ± 8.8 years, 65.6 % were female, with elevated surgical risk (median STS 4.3, IQR: 2.7-7.3). The 2 most common anatomical reasons for ineligibility were increased risk of left ventricular outflow tract obstruction (LVOTO) (n = 24, 39.3 %) and annular size (n = 29, 47.5 %). During follow-up (median 277 [162-555] days) there were 7 deaths (11.5 %) and 12 (19.7 %) hospitalizations for heart failure. Management strategies included high-risk M-TEER in 11 patients (1 death [9.0 %], 0 HF hospitalizations [0 %]), surgery in 9 patients (0 deaths, 1 HF hospitalizations [11.1 %]), and medical management in 41 patients (6 deaths [14.6 %], 11 HF hospitalizations [26.8 %]) (p = 0.715 for mortality and p = 0.093 for HF hospitalizations). Residual MR ≥ moderate was 0 %, 50 %, and 100 % for surgery, M-TEER and medical treatment, respectively (p < 0.001).

CONCLUSIONS

One third of patients deemed ineligible for TMVR are candidates for high-risk M-TEER or surgery with acceptable morbidity and mortality. Our results have practical implications for patient management.

Left and Right Ventricular Hemodynamic Response After Transcatheter Mitral Valve Replacement

Background

Transcatheter mitral valve replacement (TMVR) represents a novel treatment option for patients with mitral regurgitation (MR), but little is known about the hemodynamic impact of MR elimination following TMVR. We sought to investigate the hemodynamic impact of TMVR on left ventricular (LV) and right ventricular (RV) function using noninvasive pressure-volume loops.

Methods

All consecutive patients undergoing TMVR with dedicated devices between May 2016 and August 2022 were enrolled. The end-diastolic and end-systolic pressure-volume relationships were estimated from 26 patients using single-beat echocardiographic measurements at baseline and after TMVR at discharge. RV function was assessed by RV-pulmonary artery (PA) coupling and RV fractional area change. One-year follow-up was available for 19 patients. The prognostic impact of calculated end-diastolic volume at an end-diastolic pressure of 20 mmHg (VPed20) reduction was assessed by Cox regression.

Results

A total of 26 patients (77.0 years [interquartile range 73.9-80.1], N = 17 [65.4%] male) with successful TMVR were included (secondary MR [N = 21, 80.8%]; median LV ejection fraction was 37.0% [interquartile range 30.7-50.7]). At discharge, a decrease in VPed20 (p < 0.001) indicating leftward shift of end-diastolic pressure-volume relationship, and an increase of the end-systolic elastance slope (p = 0.007) were observed after TMVR. No changes were observed for RV-PA coupling (p = 0.19) and RV fractional area change (p = 0.22). At 1-year follow-up, LV contractility (end-systolic elastance) and RV-PA coupling remained stable. Vped20 reduction at discharge was significantly associated with 1-year all-cause mortality or heart failure hospitalization (hazard ratio 0.16, 95% CI 0.04-0.71, p = 0.016).

Conclusions

Noninvasive assessment of pressure-volume loops demonstrated early LV reverse remodeling and improved LV contractility, while RV performance was preserved. These results indicate the potential prognostic impact of complete MR elimination after TMVR.

Outcomes After Transcatheter Mitral Valve Replacement According to Regurgitation Etiology

BACKGROUND

Whether transcatheter mitral valve replacement (TMVR) devices perform similarly with respect to the underlying mitral regurgitation (MR) etiology remains unknown. The aim of the present analysis was to assess outcomes of TMVR according to the MR underlying etiology among the CHoice of OptImal transCatheter trEatment for Mitral Insufficiency (CHOICE-MI) registry.

METHODS

Of 746 patients, 229 patients (30.7%) underwent TMVR. The study population was subdivided according to primary, secondary, or mixed MR. Patients with mitral annular calcification were excluded. The primary study endpoint was a composite endpoint of all-cause mortality or hospitalization for heart failure at 1 year. Secondary study endpoints were all-cause and cardiovascular mortality at 1 year, New York Heart Association functional class, and residual MR, both at discharge and 1 year.

RESULTS

The predominant MR etiology was secondary MR (58.4%), followed by primary MR (28.7%) and mixed MR (12.9%). Technical success and procedural mortality were similar according to MR etiology. Discharge echocardiography revealed residual MR 2+ in 11.3%, 3.7%, and 5.3% of patients with primary, secondary, and mixed MR, respectively (P = .1). MR elimination was similar in all groups up to the 1-year follow-up. There was no difference in terms of primary combined outcome occurrence according to MR etiology. One-year all-cause mortality was reported in 28.8%, 24.2%, and 32.1% of patients with primary, secondary, and mixed MR, respectively (P = .07).

CONCLUSIONS

In our study we did not find differences in short-term and 1-year outcomes after TMVR according to MR etiology.

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.

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.

Immune response following transcatheter aortic valve procedure

Aortic valve stenosis is the most common type of heart valve disease in the United States and Europe and calcific aortic stenosis (AS) affects 2-7% of people aged 65 years and older. Aortic valve replacement (AVR) is the only effective treatment for individuals with this condition. Transcatheter Aortic Valve Replacement (TAVR) has been widely accepted as a minimally invasive therapeutic approach for addressing symptomatic AS in patients who are considered to have a high risk for traditional surgical intervention. TAVR procedure may have a paradoxical effect on the immune system and inflammatory status. A major portion of these immune responses is regulated by activating or inhibiting inflammatory monocytes and the complement system with subsequent changes in inflammatory cytokines. TAVR has the potential to induce various concurrent exposures, including disruption of the native valve, hemodynamic changes, antigenicity of the bioprosthesis, and vascular damage, which finally lead to the development of inflammation. On the other hand, it is important to acknowledge that TAVR may also have anti-inflammatory effects by helping in the resolution of stenosis.The inflammation and immune response following TAVR are complex processes that significantly impact procedural outcomes and patient well-being. Understanding the underlying mechanisms, identifying biomarkers of inflammation, and exploring therapeutic interventions to modulate these responses are crucial for optimizing TAVR outcomes. Further research is warranted to elucidate the precise immunological dynamics and develop tailored strategies to attenuate inflammation and enhance post-TAVR healing while minimizing complications.

Association Between Clinical Trial Participation Status and Outcomes With Mitral Transcatheter Edge-to-Edge Repair

BACKGROUND

Clinical trials have demonstrated the efficacy and safety of mitral transcatheter edge-to-edge repair (M-TEER) for selected patients with severe mitral regurgitation. However, the generalizability of trial results to real-world patients remains uncertain.

OBJECTIVES

The authors aimed to compare baseline characteristics and in-hospital outcomes among trial participants with nonparticipants undergoing M-TEER.

METHODS

Using the National Inpatient Sample database years 2016-2020, M-TEER admissions were identified and categorized into trial participants vs none. We also identified a cohort of trial noneligible patients based on clinical exclusion criteria from pivotal trials. Multivariate regression analysis was performed to compare in-hospital outcomes. The primary outcome was in-hospital mortality, and secondary outcomes included in-hospital complications, length of stay, and hospitalization cost.

RESULTS

Among 38,770 M-TEER admissions from 2016 to 2020, 11,450 (29.5%) were trial participants, 22,975 (59.3%) were eligible nonparticipants, and 2,960 (7.6%) were noneligible. Baseline characteristics and comorbidity profiles were mostly similar between trial participants vs eligible nonparticipants. In-hospital mortality (adjusted OR [aOR]: 0.98; 95% CI: 0.60-1.62), cardiogenic shock (aOR: 1.06; 95% CI: 0.80-1.42), mechanical circulatory support (aOR: 0.91; 95% CI: 0.58-1.41), mechanical ventilation (aOR: 1.03; 95% CI: 0.74-1.42), and conversion to mitral valve surgery (aOR: 1.08; 95% CI: 0.57-2.03) were not different between both groups. Conversely, M-TEER for noneligible patients was associated with higher rates of mortality (aOR: 6.27; 95% CI: 3.75-10.45) and complications.

CONCLUSIONS

The majority of real-world M-TEER patients would have been eligible for clinical trial participation and had comparable clinical profiles and in-hospital outcomes to trial participants. However, noneligible patients had worse in-hospital outcomes compared with trial participants.

Anterior mitral leaflet laceration using the MitraCut technique for transapical transcatheter Tendyne implantation after unsuccessful Carillon indirect annuloplasty: a case report

Background

The introduction of a transapical transcatheter beating heart replacement system has significantly expanded therapeutic options for patients with severely diseased mitral valves, particularly those ineligibles for traditional surgery or transcatheter repair. However, challenges, such as left ventricular outflow tract obstruction (LVOT-O) and the risk of dynamic systolic anterior motion (SAM) in cases with elongated anterior mitral leaflet (AML) post-prosthesis implantation, impede the widespread adoption of transcatheter mitral valve replacement (TMVR).

Case summary

In 2022, a 75-year-old male with severe mixed-genesis mitral regurgitation (MR) underwent Carillon Mitral Contour System annuloplasty. Recurrent heart failure admissions (New York Heart Association IV) and prohibitive risk for open-heart surgery (European System for Cardiac Operative Risk Evaluation II 8.27%) prompted evaluation for Tendyne TMVR with the MitraCut technique. This beating heart transapical approach involved scissor-mediated splitting of the elongated 27 mm AML, essential for mitigating LVOT-O risk and dynamic SAM. The screening echocardiogram revealed the poorly tethered AML near the thickened septum at the simulated neo-LVOT site.

Discussion

This case underscores the intricate management challenges associated with severe MR, highlighting the successful application of the MitraCut technique as a viable alternative in high-risk scenarios. The imperative for further research and clinical studies is emphasized to comprehensively elucidate outcomes and safety parameters, providing valuable insights for refining TMVR applications within this context.

Comparison of Direct Oral Anticoagulants vs Vitamin K Antagonists After Transcatheter Mitral Valve Replacement

BACKGROUND

There is currently no established recommendation for antithrombotic treatment following transcatheter mitral valve replacement (TMVR). However, based on the analogy with surgical mitral bioprosthesis, vitamin K antagonists (VKAs) are predominantly used.

OBJECTIVES

The purpose of this study was to compare bleeding and thrombotic events associated with direct oral anticoagulants (DOACs) or VKAs in a prospective cohort of TMVR patients.

METHODS

We enrolled consecutive patients who underwent transseptal TMVR using a SAPIEN family prosthesis at our center between 2011 and 2023. The primary outcome was the occurrence of bleeding. VKAs were administered to patients until October 2019, after which DOACs were prescribed. The median follow-up was 4.7 months (Q1-Q3: 2.6-6.7 months).

RESULTS

A total of 156 patients were included. The mean age was 65 ± 18.5 years, and 103 patients (66%) were women. The median EuroSCORE II was 7.48% (Q1-Q3: 3.80%-12.97%). Of the participants, 20.5% received DOACs and 79.5% were treated with VKAs. The primary outcome was observed in 50 (40%) patients in the VKA group and 3 (9%) patients in the DOAC group (adjusted HR: 0.21; 95% CI: 0.06-0.74; P = 0.02). Treatment with DOAC was associated with a shorter length of hospital stay. No significant differences were found in terms of thrombotic events, major vascular complications, stroke, or death.

CONCLUSIONS

The use of DOACs after TMVR, compared with VKAs, appears to reduce the risk of bleeding complications and decrease the length of hospital stay for patients, without a significant increase in the risk of thrombotic events.

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.

Characteristics and outcomes of patients undergoing transcatheter mitral valve replacement with the Tendyne system

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has emerged as alternative to transcatheter edge-to-edge repair (TEER) for treatment of mitral regurgitation (MR); however, the role of TMVR with the Tendyne system among established treatments of MR is not well defined. We assessed characteristics and outcomes of patients treated with the Tendyne system in the current clinical practice.

METHODS

We reviewed patients who underwent cardiac computed tomography and were judged eligible for the Tendyne system.

RESULTS

A total of 63 patients were eligible for TMVR with the Tendyne system. Of these, 17 patients underwent TMVR, and 46 were treated by TEER. Patients treated with the Tendyne system were more likely to have a high transmitral pressure gradient and unsuitable mitral valve morphology for TEER than those treated with TEER. TMVR with the Tendyne system reduced the severity of MR to less than 1 + in 94.1% of the patients at discharge and achieved a greater reduction in left ventricular (LV) end-diastolic volume at the 30-day follow-up compared with TEER. In contrast, patients treated with the Tendyne system had a higher 30-day mortality than those treated with TEER, while the mortality between 30 days and one year was comparable between Tendyne and TEER.

CONCLUSIONS

Among patients eligible for the Tendyne system, approximately a quarter of the patients underwent TMVR with the Tendyne system, which led substantial reduction of MR and LV reverse remodeling than TEER. In contrast, the 30-day mortality rate was higher after TMVR with the Tendyne compared to TEER.

Heart Failure and Secondary Mitral Regurgitation: A Contemporary Review

Secondary mitral regurgitation (SMR) in patients with heart failure (HF) is associated with significant morbidity and mortality. In recent decades, SMR has received increasing scientific attention. Advances in echocardiography, computed tomography and cardiac magnetic resonance imaging have refined our ability to diagnose, quantify and characterize SMR. Concurrently, the treatment options for this high-risk patient population have continued to evolve. Guideline-directed medical therapies including beta-blockers, angiotensin receptor-neprilysin inhibitors, mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors target the underlying cardiomyopathy, and along with diuretics to treat pulmonary congestion, remain the cornerstone of therapy. Cardiac resynchronization therapy also reduces MR, alleviates symptoms and prolongs life in selected HF patients with SMR. While data supporting surgical mitral valve repair or replacement for SMR are limited, transcatheter edge-to-edge repair (TEER) has been demonstrated to improve survival, reduce the rate of hospitalization for heart failure, and improve functional capacity and quality-of-life in select patients with SMR who remain symptomatic despite medical therapy. Emerging transcatheter mitral valve repair and replacement technologies are undergoing investigation in TEER-eligible and TEER-ineligible patients. The optimal management of HF patients with SMR requires a multidisciplinary team of cardiologists, cardiac surgeons, imaging experts, and other organ specialists to select the best treatment approaches to improve the prognosis of these high-risk patients.

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.

Update on Transcatheter Treatment of Mitral and Tricuspid Valve Regurgitation

PURPOSE OF REVIEW

Mitral and tricuspid regurgitation represents a clinical challenge. They are associated with a poor prognosis, and many patients are not eligible for conventional surgery. Transcatheter therapies have been the focus of numerous studies and devices over the past decade. Here, we provide a summary of current options for transcatheter treatment of these 2 entities.

RECENT FINDINGS

Recent studies have demonstrated the benefits of edge-to-edge repair for increasing numbers of patients. Encouraging early results with transcatheter valve replacement are also becoming available. To date, transcatheter edge-to-edge repair is currently the first-line transcatheter treatment for both mitral and tricuspid regurgitation for many patients who are not candidates for surgery. A number of transcatheter replacement devices are under development and clinical investigation but, for the most part, their current use is limited to compassionate cases or clinical trials.

Transfemoral Transcatheter Mitral Valve Implantation With a Dedicated Device in a Rheumatic Mitral Stenosis Patient

A 65-year-old obese woman with rheumatic heart disease and restrictive lung disease presented with decompensated heart failure. Evaluation demonstrated severely thickened mitral valve leaflets, severe mitral stenosis, and moderate mitral regurgitation. She underwent successful transfemoral transseptal transcatheter mitral valve replacement with a dedicated valve resulting in improved functional status. (Level of Difficulty: Advanced.).

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

Prevention of LVOT Obstruction by Device-Mediated Laceration of the Anterior Mitral Valve Leaflet During TMVR

Left ventricular outflow tract obstruction represents a life-threatening complication in patients undergoing transcatheter mitral valve replacement. Interventional approaches to prevent left ventricular outflow tract obstruction are complex and require exceptional procedural expertise. We demonstrate feasibility and safety of first-in-human device-mediated mechanical laceration of the anterior mitral valve leaflet prior to transapical transcatheter mitral valve replacement. (Level of Difficulty: Advanced.).

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.

Racial and Ethnic Disparities in the Use and Outcomes of Transcatheter Mitral Valve Replacement: Analysis From the National Inpatient Sample Database

Background Racial and ethnic disparities in outcomes exist following many cardiac procedures. Transcatheter mitral valve replacement (TMVR) has grown as an alternative to mitral valve surgery for patients at high surgical risk. The outcomes of TMVR by race and ethnicity are unknown. We aimed to evaluate racial and ethnic disparities in the outcomes of TMVR. Methods and Results We analyzed the National Inpatient Sample database from 2016 to 2020 to identify hospitalizations for TMVR. Racial and ethnic disparities in TMVR outcomes were determined using logistic regression models. Between 2016 and 2020, 5005 hospitalizations for TMVR were identified, composed of 3840 (76.7%) White race, 505 (10.1%) Black race, 315 (6.3%) Hispanic ethnicity, and 345 (6.9%) from other races (Asian, Pacific Islander, American Indian or Alaska Native, Other). Compared with other racial and ethnic groups, Black patients were significantly younger and more likely to be women (both P<0.01). There were no significant differences between White, Black, and Hispanic patients in in-hospital mortality (5.2% versus 5.0% versus <3.5%; P=0.89) and procedural complications, including heart block (P=0.91), permanent pacemaker (P=0.49), prosthetic valve dysfunction (P=0.45), stroke (P=0.37), acute kidney injury (P=0.32), major bleeding (P=0.23), and blood transfusion (P=0.92), even after adjustment for baseline characteristics. Adjusted vascular complications were higher in Black compared with White patients (P=0.03). Trend analysis revealed a significant increase in TMVR in all racial and ethnic groups from 2016 to 2020 (Ptrend<0.05). Conclusions Between 2016 and 2020, Black and Hispanic patients undergoing TMVR had similar in-hospital outcomes compared with White patients, except for higher vascular complications in Black patients. Further comparative studies of TMVR in clinically similar White patients and other racial and ethnic groups are warranted to confirm our findings.

Transcatheter edge-to-edge mitral valve repair in mitral regurgitation: current status and future prospects

INTRODUCTION

Mitral regurgitation (MR) is associated with substantial morbidity and mortality. Within the past 15 years, mitral valve edge-to-edge repair (M-TEER) has developed from an experimental approach to a guideline-recommended, safe, and effective treatment option for patients with severe primary or secondary mitral regurgitation.

AREAS COVERED

This review covered relevant publications of M-TEER and summarizes the development of M-TEER devices within the last 15 years. It outlines anatomical challenges which drove the evolution of M-TEER devices, provides an overview about the current state of clinical application and research, and offers an outlook into the future of transcatheter mitral valve treatment.

EXPERT OPINION

The development and refinement of new M-TEER device generations offer the possibility to treat a wide range of mitral valve anatomies. Choosing the best device for the individual anatomic properties of the patients and considering comorbidities is the key to maximized MR reduction, minimalized complication rates, and thus optimized postinterventional prognosis. Independent from prognostic implications, quality of life has become an important patient-centered outcome that can be improved by M-TEER in virtually all patients treated.

Characteristics of Clinical Trial Sites for Novel Transcatheter Mitral and Tricuspid Valvular Therapies

Importance

Racial and ethnic minority and socioeconomically disadvantaged patients have been underrepresented in randomized clinical trials. Efforts have focused on enhancing inclusion of minority groups at sites participating at clinical trials; however, there may be differences in the patient populations of the sites that participate in clinical trials.

Objective

To identify any differences in the racial, ethnic, and socioeconomic composition of patient populations among candidate sites in the US that did vs did not participate in trials for novel transcatheter therapies.

Design, Setting, and Participants

This cross-sectional analysis used Medicare Provider Claims from 2019 for patients admitted to hospitals in the US. All clinical trials for transcatheter mitral and tricuspid valve therapies and the hospitals participating in each of the trials were identified using ClinicalTrials.gov. Hospitals with active cardiac surgical programs that did not participate in the trials were also identified. Data analysis was performed between July 2021 and July 2022.

Exposures

Multivariable linear regression models were used to identify differences in racial, ethnic, and socioeconomic characteristics among patients undergoing cardiac surgery or transcatheter aortic valve replacement at trial vs nontrial hospitals.

Main Outcome and Measures

The main outcome of the study was participation in a clinical trial for novel transcatheter mitral or tricuspid valve therapies.

Results

A total of 1050 hospitals with cardiac surgery programs were identified, of which 121 (11.5%) participated in trials for transcatheter mitral or tricuspid therapies. Patients treated in trial hospitals had a higher median zip code-based household income (difference of $5261; 95% CI, $2986-$7537), a lower Distressed Communities Index score (difference of 5.37; 95% CI, 2.59-8.15), and no significant difference in the proportion of patients dual eligible for Medicaid (difference of 0.86; 95% CI, -2.38 to 0.66). After adjusting for each of the socioeconomic indicators separately, there was less than 1% difference in the proportion of Black and Hispanic patients cared for at hospitals participating vs not participating in clinical trials.

Conclusions and Relevance

In this cohort study among candidate hospitals for clinical trials for transcatheter mitral or tricuspid valve therapies, trial hospitals took care of a more socioeconomically advantaged population than nontrial hospitals, with a similar proportion of Black and Hispanic patients. These data suggest that site selection efforts may improve enrollment of socioeconomically disadvantaged patients but may not improve the enrollment of Black and Hispanic patients.

Transcatheter Mitral Valve Repair Versus Transcatheter Mitral Valve Replacement in Patients with Mitral insufficiency

AIMS

Mitral regurgitation (MR) is the most prevalent form of valvular heart disease. Transcatheter mitral valve repair (TMVr) and transcatheter mitral valve replacement (TMVR) have recently emerged as alternatives to open heart surgical repair or replacement. However, studies on the comparative outcomes of TMVr and TMVR are limited. This study aims to compare the demographics, complications and outcomes of TMVr and TMVR based on a real-world investigation of the National Inpatient Sample (NIS) database.

METHODS AND RESULTS

From 2016-2018 in the NIS database, a total of 210 and 3370 patients who underwent TMVR and TMVr, respectively, were selected. The mean age of the patients was 75.99 years (TMVr) and 69.6 years (TMVR) (p <0.01). The mortality of patients who received TMVR was higher compared to that of patients who were treated with TMVr (8.1 vs. 1.9%, p <0.01). The patients who underwent TMVR were more likely to suffer perioperative complications including blood transfusions (16.2 vs. 5.0%, p <0.01) and acute kidney injury (22.9 vs. 13.3%, p <0.01). The average cost of treatment was higher (USD $278864 vs. USD $216845, p <0.01), and the average duration of hospitalization was longer (8.73 vs. 4.17 d, p <0.01) for TMVR compared to TMVr. When taking into account perioperative comorbidities and other factors, TMVR was associated with a worse adjusted in-hospital mortality (odds ratio [OR], 3.307 [95% CI, 1.533-7.136]; p <0.01).

CONCLUSION

TMVr is associated with lower mortality, peri-procedural morbidity, and resource use compared to TMVR. A patient-centered approach can help guide decision-making about the choice of intervention for the individual patient and more studies evaluating the long-term outcomes and durability of TMVR are needed at present.

Impact of sex on in-hospital mortality and 90-day readmissions in patients undergoing transcatheter mitral valve replacement (TMVR): Analysis from the nationwide readmission database

OBJECTIVES

To evaluate sex differences in in-hospital mortality and 90-day readmission rates among patients undergoing transcatheter mitral valve replacement (TMVR) in the United States of America.

BACKGROUND

Women have higher rates of mortality and rehospitalization than men following many cardiac procedures. TMVR has grown as an alternative to mitral valve surgery for patients at high surgical risk. The rates of TMVR mortality and rehospitalization by sex are unknown.

METHODS

We analyzed the Nationwide Readmissions Database (NRD) from 2016 to 2019 to identify hospitalizations for TMVR. Sex differences in in-hospital mortality and 90-day readmissions were determined using logistic regression models.

RESULTS

Between 2016 and 2019, 4109 hospitalizations for TMVR were identified, comprised of 1758 (42.8%) men and 2351 (57.2%) women. The median age was 74 years for both men and women. There was no significant difference in in-hospital mortality during index hospitalization (6.51% vs. 6.69%; p = 0.852) and all-cause 90-day readmission (28.19% vs. 29.59%; p = 0.563) between men and women. Across the study period, trend analysis did not reveal a significant change in in-hospital mortality (men p = 0.087, women p = 0.194) or 90-day readmission rates (men p = 0.569, women p = 0.454).

CONCLUSIONS

In patients undergoing TMVR, in-hospital mortality and 90-day readmissions are similar between men and women. Between 2016 and 2019, TMVR in-hospital mortality and 90-day readmission rates remained unchanged. Further research is necessary to confirm these findings.

Automated mitral valve assessment for transcatheter mitral valve replacement planning

Transcatheter mitral valve replacement (TMVR) has emerged as a minimally invasive alternative for treating patients suffering from mitral valve disease. The number of TMVR procedures is expected to rise as devices currently in clinical trials obtain approval for commercialization. Automating the planning of such interventions becomes, therefore, more relevant in an attempt to decrease inter-subject discrepancies and time spent in patient assessment. This study evaluates the performance of an automated method for detection of anatomical landmarks and generation of relevant measurements for device selection and positioning. Cardiac CT scans of 70 patients were collected retrospectively. Fifty scans were used to generate a statistical shape model (SSM) of the left heart chambers at ten different timepoints, whereas the remaining 20 scans were used for validation of the automated method. The clinical measurements resulting from the anatomical landmarks generated automatically were compared against the measurements obtained through the manual indication of the corresponding landmarks by three observers, during systole and diastole. The automatically generated measurements were in close agreement with the user-driven analysis, with intraclass correlation coefficients (ICC) consistently lower for the saddle-shaped (ICCArea = 0.90, ICCPerimeter 2D = 0.95, ICCPerimeter 3D = 0.93, ICCAP-Diameter = 0.71, ICCML-Diameter = 0.90) compared to the D-shaped annulus (ICCArea = 0.94, ICCPerimeter 2D = 0.96, ICCPerimeter 3D = 0.96, ICCAP-Diameter = 0.95, ICCML-Diameter = 0.92). The larger differences observed for the saddle shape suggest that the main discrepancies occur in the aorto-mitral curtain. This is supported by the fact that statistically significant differences are observed between the two annulus configurations for area (p < 0.001), 3D perimeter (p = 0.009) and AP diameter (p < 0.001), whereas errors for 2D perimeter and ML diameter remained almost constant. The mitral valve center deviated in average 2.5 mm from the user-driven position, a value comparable to the inter-observer variability. The present study suggests that accurate mitral valve assessment can be achieved with a fully automated method, what could result in more consistent and shorter pre-interventional planning of TMVR procedures.

Transcatheter tricuspid valve interventions: Current status and future perspectives

The development of transcatheter therapies to treat valvular heart diseases has changed the rules of the game, particularly in the case of aortic stenosis and mitral regurgitation. In the last years, the tricuspid valve has also been the focus of these percutaneous techniques for several reasons: (1) tricuspid regurgitation is a frequent disease associated with poor clinical outcomes in spite of medical treatment, leading to end-stage right ventricular heart failure, (2) surgical tricuspid valve repair or replacement has been the treatment of choice for patients with tricuspid valve disease, but high mortality rates for isolated surgical tricuspid valve intervention have been reported in the literature, and (3) most patients with tricuspid pathology are ultimately denied cardiac surgery because of their comorbidity burden. Thus, in this context the development of less invasive catheter-based therapies would be of high clinical relevance. The present review provides an overview regarding the framework of chronic tricuspid regurgitation transcatheter therapeutic options, summarizes the transcatheter systems under clinical use or clinical evaluation with their technical features, and describes the updated current evidence in this challenging and evolving field.

Imaging in transcatheter native mitral valve replacement with Tendyne mitral valve system: Echocardiographic pathway for the interventional imager

The interaction between the implanter team and the imager team is critical to the success of transcatheter native mitral valve replacement (TMVR), a novel interventional procedure in the therapeutic arsenal for mitral regurgitation. This imaging scenario necessitates the addition of a new dedicated professional figure, dubbed "the interventional imager," with specific expertise in structural heart disease procedures. As its clinical application grows, knowledge of the various imaging modalities used in the TMVR procedure is required for the interventional imager and beneficial for the interventional implanter team. The purpose of this review is to describe the key steps of the procedural imaging pathway in TMVR using the Tendyne mitral valve system, with an emphasis on echocardiography. Pre-procedure cardiac multimodality imaging screening and planning for TMVR can determine patient eligibility based on anatomic features and measurements, provide measurements for appropriate valve sizing, plan/simulate the access site, catheter/sheath trajectory, and prosthesis positioning/orientation for correct deployment, and predict the risks of potential procedural complications and their likelihood of success. Step-by-step echocardiographic TMVR intraoperative guidance includes: apical access assessment; support for catheter/sheath localization, trajectory and positioning, valve positioning and clocking; post deployment: correct clocking; hemodynamic assessment; detection of perivalvular leakage; obstruction of the left ventricular outlet tract; complications. Knowledge of the multimodality imaging pathway is essential for interventional imagers and critical to the procedure's success.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Transcatheter therapies for secondary mitral regurgitation in advanced heart failure: what are we aiming for?

A severe secondary mitral regurgitation (SMR) can be found in a significant portion of patients affected by advanced heart failure (AHF). Conventional therapies (optimal medical therapy, devices, surgery) present restricted clinical efficacy in this stage of the left ventricle disease which is burdened by high mortality and morbidity rates. Although the treatment of choice is represented by heart transplantation (HTx), there is an unmet need related to the limited supply of donor hearts (as opposed to the growing prevalence of AHF) and the low eligibility of highly symptomatic patients. In case of concomitant severe SMR, transcatheter mitral valve therapies (repair and replacement) may play a crucial role in this setting. While a direct prognostic improvement after correction of SMR has yet to be proved, AHF patients can benefit from the following: hemodynamic stabilization, symptomatic relief, normalization of pulmonary arterial pressures, and reduction in hospitalizations for acute heart failure. Obtaining these results may lead to the clinical consequences of reaching the HTx in good enough clinical status (bridge to heart transplantation), becoming eligible for the HTx (bridge to HTx candidacy), and being delisted for clinical improvement (bridge to recovery). Therefore, achieving traditional secondary endpoints in patients with AHF and SMR can translate into significant clinical implications.

Catheter-Based Interventions for the Management of Valvular Heart Disease During Pregnancy

Pregnancy is associated with a significant increase in hemodynamic burden. These changes can lead to maternal morbidity and mortality as well as unfavorable fetal outcomes in patients with valvular heart disease and limited cardiac reserve. Mechanical interventions may be needed for the management of severe hemodynamic deterioration not responding to medical therapy. Catheter-based percutaneous interventions can provide an alternative therapy to surgery during pregnancy. The purpose of this article is to review indications, potential advantages, and limitations of catheter-based interventions for the management of women with valvular heart disease in pregnancy.

Editor-in-Chief's Top Picks From 2021

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. This process has become a true labor of love due to the time they require, but I am motivated by the sheer number of listeners (16M+), and it has allowed me to familiarize myself with every paper that we publish. Thus, I have selected the top 100 papers (both Original Investigations and Review Articles) from distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations and podcasts. The highlights comprise the following sections: Artificial Intelligence & Machine Learning (NEW section), Basic & Translational Research, Biomarkers (NEW section), Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Cardiovascular Disease in Women, Coronary Disease & Interventions, Congenital Heart Disease, Coronavirus, Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Vascular Medicine, and Valvular Heart Disease.^1-100.

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.