Transcatheter Mitral Valve Implantation: Current Status and Future Perspectives

Prevalence, mortality, cost, and disparities in transcatheter mitral valve repair and replacement in cancer patients: Artificial intelligence and propensity score national 5-year analysis of 7495 procedures

INTRODUCTION

We conducted the first comprehensive evaluation of the therapeutic value and safety profile of transcatheter mitral edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) in individuals concurrently afflicted with cancer.

METHODS

Utilizing the National Inpatient Sample (NIS) dataset, we analyzed all adult hospitalizations between 2016 and 2020 (n = 148,755,036). The inclusion criteria for this retrospectively analyzed prospective cohort study were all adult hospitalizations (age 18 years and older). Regression and machine learning analyses in addition to model optimization were conducted using ML-PSr (Machine Learning-augmented Propensity Score adjusted multivariable regression) and BAyesian Machine learning-augmented Propensity Score (BAM-PS) multivariable regression.

RESULTS

Of all adult hospitalizations, there were 5790 (0.004%) TMVRs and 1705 (0.001%) TEERs. Of the total TMVRs, 160 (2.76%) were done in active cancer. Of the total TEERs, 30 (1.76%) were done in active cancer. After the comparable rates of TEER/TMVR in active cancer in 2016, the prevalence of TEER/TMVR was significantly less in active cancer from 2017 to 2020 (2.61% versus 7.28% p < 0.001). From 2017 to 2020, active cancer significantly decreased the odds of receiving TEER or TMVR (OR 0.28, 95%CI 0.13-0.68, p = 0.008). In patients with active cancer who underwent TMVR/TEER, there were no significant differences in socio-economic disparities, mortality or total hospitalization costs.

CONCLUSION

The presence of malignancy does not contribute to increased mortality, length of stay or procedural costs in TMVR or TEER. Whereas the prevalence of TMVR has increased in patients with active cancer, the utilization of TEER in the context of active cancer is declining despite a growing patient population.

Understanding transcatheter edge-to-edge repair "knobology": Advanced catheter steering for different scenarios of transseptal puncture

Following the introduction in the latest European and American guidelines, transcatheter edge-to-edge repair has become a valid alternative to surgery for ineligible patients. Among the available technologies, MitraClip (Abbott) was the first to be introduced for the percutaneous treatment of mitral regurgitation with the edge-to-edge technique. Although its safety and effectiveness has been widely demonstrated, the optimal procedural results are highly dependent from operators' experience. In this manuscript, we provide a full guide of advanced steering maneuvers of MitraClip in different scenarios of transseptal puncture.

Mortality and resource utilization in surgical versus transcatheter repeat mitral valve replacement: A national analysis

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has garnered interest as a viable alternative to the traditional surgical mitral valve replacement (SMVR) for high-risk patients requiring redo operations. This study aims to evaluate the association of TMVR with selected clinical and financial outcomes.

METHODS

Adults undergoing isolated redo mitral valve replacement were identified in the 2016-2020 Nationwide Readmissions Database and categorized into TMVR or SMVR cohorts. Various regression models were developed to assess the association between TMVR and in-hospital mortality, as well as additional secondary outcomes. Transseptal and transapical catheter-based approaches were also compared in relation to study endpoints.

RESULTS

Of an estimated 7,725 patients, 2,941 (38.1%) underwent TMVR. During the study period, the proportion of TMVR for redo operations increased from 17.8% to 46.7% (nptrend<0.001). Following adjustment, TMVR was associated with similar odds of in-hospital mortality (AOR 0.82, p = 0.48), but lower odds of stroke (AOR 0.44, p = 0.001), prolonged ventilation (AOR 0.43, p<0.001), acute kidney injury (AOR 0.61, p<0.001), and reoperation (AOR 0.29, p = 0.02). TMVR was additionally correlated with shorter postoperative length of stay (pLOS; β -0.98, p<0.001) and reduced costs (β -$10,100, p = 0.002). Additional analysis demonstrated that the transseptal approach had lower adjusted mortality (AOR 0.44, p = 0.02), shorter adjusted pLOS (β -0.43, p<0.001), but higher overall costs (β $5,200, p = 0.04), compared to transapical.

CONCLUSIONS

In this retrospective cohort study, we noted TMVR to yield similar odds of in-hospital mortality as SMVR, but fewer complications and reduced healthcare expenditures. Moreover, transseptal approaches were associated with lower adjusted mortality, shorter pLOS, but higher cost, relative to the transapical. Our findings suggest that TMVR represent a cost-effective and safe treatment modality for patients requiring redo mitral valve procedures. Nevertheless, future studies examining long-term outcomes associated with SMVR and TMVR in redo mitral valve operations, are needed.

Temporal trends of frame expansion and paravalvular leak reduction after transcatheter aortic valve replacement with self-expandable prostheses

BACKGROUND

Paravalvular leakage (PVL) is a common finding after transcatheter aortic valve replacement (TAVR) and affects late clinical outcome. It is more frequent with self-expandable (SE) transcatheter-heart-valve (THV). Few is known about SE-THV expansion after implantation. The purpose is to assess SE-THV frame expansion and its possible influence on PVL.

METHODS

We designed a prospective pilot study to assess the time-course of SE-THV frame dimensions and PVL after TAVR. Consecutive patients undergoing TAVR with SE-THV were enrolled. Prosthesis fluoroscopy and echocardiography were prospectively performed immediately after TAVR (T0) and before discharge (T1) to grade PVL. Prosthesis diameters were assessed in 2 fluoroscopic orthogonal views. PVL reduction ≥1+ from T0 to T1 at echocardiography was the primary study endpoint.

RESULTS

Twenty-five patients were enrolled. Mean interval between T0 and T1 evaluations was 5 days. Grade 1 or 2 was present in 76% of patients at T0 and in 68% at T1 (P=0.034). A total of 7 patients (28%) improved PVL ≥1 grade from T0 to T1. Differences between T0 and T1 fluoroscopic diameters were not statistically significant. When comparing the diameter changes according to PVL evolution, patients with PVL improvement (as compared with those without) had significantly larger minimum diameter increase at both annulus/inflow (P=0.016) and outflow/distal edge (P=0.027).

CONCLUSIONS

PVL may improve in the early days after SE-THV and those patients with PVL improvement may have THV frame expansion. Further studies are needed to confirm such preliminary observations and to establish the clinical relevance of this phenomenon.

A case report of percutaneous intramyocardial septal radiofrequency ablation in an adult with re-obstruction after Morrow procedure

Background

Some patients with hypertrophic cardiomyopathy (HCM) re-occur with drug-refractory symptoms but are not eligible for re-operation after the Morrow procedure. Traditional treatment options are limited. We present the first case of the use of ultrasound-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA) for the treatment of a patient with HCM combined with congenital anatomically corrected malposition of the great arteries (MGA) after Morrow procedure.

Case summary

A 61-year-old male patient with congenital MGA, who had been treated with the Morrow procedure for HCM, had worsening symptoms in recent years that were difficult to control medically. He was diagnosed with occult obstructive HCM by stress echocardiography. After multi-disciplinary discussion, this patient was treated with PIMSRA. The post-operative clinical outcome was remarkable, with a significant decrease in septal thickness and disappearance of the left anterior branch conduction block.

Conclusion

Percutaneous intramyocardial septal radiofrequency ablation is feasible and can be one of the options for the treatment of patients with HCM, especially those who cannot choose Morrow procedure. However, it still needs a large sample of clinical trials to validate its clinical effectiveness.

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.

Degenerative mitral regurgitation

Degenerative mitral regurgitation is a major threat to public health and affects at least 24 million people worldwide, with an estimated 0.88 million disability-adjusted life years and 34,000 deaths in 2019. Improving access to diagnostic testing and to timely curative therapies such as surgical mitral valve repair will improve the outcomes of many individuals. Imaging such as echocardiography and cardiac magnetic resonance allow accurate diagnosis and have provided new insights for a better definition of the most appropriate timing for intervention. Advances in surgical techniques allow minimally invasive treatment with durable results that last for ≥20 years. Transcatheter therapies can provide good results in select patients who are considered high risk for surgery and have a suitable anatomy; the durability of such repairs is up to 5 years. Translational science has provided new knowledge on the pathophysiology of degenerative mitral regurgitation and may pave the road to the development of medical therapies that could be used to halt the progression of the disease.

The Predictors and Outcomes of Functional Mitral Stenosis following Surgical Mitral Valve Repair: A Retrospective Analysis

To optimize mitral valve repair outcomes, it is crucial to comprehend the predictors of functional mitral valve stenosis (FMS), to enhance preoperative assessments, and to adapt intraoperative treatment strategies. This study aimed to identify FMS risk factors, contributing valuable insights for refining surgical techniques. Among 228 selected patients, 215 underwent postoperative echocardiography follow-ups, and 36 met the FMS criteria based on a mean trans-mitral pressure gradient of >5 mmHg. Patients with FMS exhibited higher pulmonary systolic arterial pressure and increased late mortality during the follow-up. Univariable logistic regression analysis identified several risk factors for FMS, including end-stage renal disease, anterior leaflet lesion, concomitant aortic valve replacement, smaller ring size, ring type, and neochordae implantation. Conversely, resection alone and resection combined with neochordae implantation had protective effects against FMS. Multivariable logistic regression analysis revealed that smaller ring sizes and patch repair independently predicted FMS. When focusing on degenerative mitral regurgitation, the neochordae implantation without resection in leaflet repair, emerged as an independent predictor of FMS. Surgeons should weigh the substantial impact of surgical procedures on postoperative trans-mitral pressure gradients, emphasizing preoperative evaluation and techniques such as precise ring size assessment and effective leaflet management.

Transcatheter mitral valve implantation using the Tendyne valve in a patient with prior transcatheter aortic valve implantation: a case report

Background

The presence of aortic and mitral disease in a patient who is not a suitable candidate for surgical correction poses significant challenges in the diagnostic workup as well as management plans. Percutaneous treatment can be staged to fix the aortic valve with transcatheter aortic valve implantation (TAVI) as a first step, followed by reassessment and percutaneous correction of mitral regurgitation (MR).

Case summary

A 65-year-old female with multiple co-morbidities presented with acute coronary syndrome and heart failure. She was diagnosed with three-vessel coronary artery disease and degenerative low-flow low-gradient severe aortic stenosis, along with severe degenerative MR with a left ventricular ejection fraction of 35%. Because of the high surgical risk, she underwent multi-vessel percutaneous coronary intervention with stenting. Transcatheter aortic valve implantation was done as a staged procedure, which partially improved her symptoms. Mitral regurgitation was not suitable for percutaneous mitral valve edge-to-edge repair. After a discussion by the heart team, she underwent transcatheter mitral valve implantation, for which the Tendyne mitral valve (Tendyne™; Abbott) was used through a transapical approach. There was no paravalvular leak, and the mean gradient across the valve was 2 mmHg. She was symptomatically better at follow-up and an echocardiogram showed a normally functioning aortic valve and Tendyne mitral valves.

Discussion

Transapical transcatheter mitral valve implantation using the Tendyne valve is a feasible option for patients with prior TAVI. This can be considered an alternative treatment for MR in patients who are not suitable for edge-to-edge mitral repair.

Bailout clipping of a leaflet perforation during mitral transcatheter edge-to-edge repair using a larger clip size: a case report

Background

Leaflet tear and perforation are serious complications of transcatheter edge-to-edge repair (TEER) using the MitraClip system for severe mitral regurgitation (MR). However, no optimal bailout strategy has been established.

Case summary

An 80-year-old woman developed heart failure due to acute ischaemic severe MR after primary percutaneous coronary intervention. Given the requirement for inotropic drugs and an intra-aortic balloon pump to stabilize her heart failure, we decided to perform TEER using the MitraClip G4 system. The NTW clip was selected considering the limited posterior leaflet, wide central MR, and delivery to the central A2/P2. The leaflet was successfully grasped, and the MR jet dramatically decreased while the clip was closed. However, the MR jet suddenly appeared after completely closing the clip arm. A new eccentric jet was detected coming from the mid-portion of the posterior leaflet, indicating leaflet perforation. We decided to manage the leaflet perforation by covering the perforated portion with a longer type of clip. An XTW clip was then carefully delivered to the previously grasped portion, after which we confirmed that the tip of the clip arm was positioned more posteriorly to the leaflet perforation. After slowly closing the clip, MR decreased to mild, with transoesophageal echocardiography showing no eccentric MR. After her haemodynamics stabilized, she was discharged 28 days after the procedure.

Discussion

This case details a successful bailout clipping of a leaflet perforation using an XTW clip. Leaflet anatomy evaluation is important to ensure that the injured portion is covered by the longer clip arm.

Multi-modality imaging for pre-procedural planning of transcatheter mitral valve interventions

Transcatheter mitral valve interventions (TMVI), either repair or replacement, are established alternative options for patients with mitral regurgitation (MR) deemed not suitable for conventional open-heart surgery. Multi-modality imaging plays a pivotal role in the selection of patients, gaining insights into the anatomy of the mitral valve the mechanism and the severity of MR, which are essential to predict the success of these procedures. The aim of this review is to provide an overview on the role of multi-modality imaging in the patient selection and pre-procedural planning of TMVI.

Contemporary Treatment and Outcomes of High Surgical Risk Mitral Regurgitation

Before the development of transcatheter interventions, patients with mitral regurgitation (MR) and high surgical risk were often conservatively treated and subject to poor prognoses. We aimed to assess the therapeutic approaches and outcomes in the contemporary era. The study participants were consecutive high-risk MR patients from April 2019 to October 2021. Among the 305 patients analyzed, 274 (89.8%) underwent mitral valve interventions, whereas 31 (10.2%) received medical therapy alone. Of the interventions, transcatheter edge-to-edge mitral repair (TEER) was the most frequent (82.0% of overall), followed by transcatheter mitral valve replacement (TMVR) (4.6%). In patients treated with medical therapy alone, non-optimal morphologies for TEER and TMVR were shown in 87.1% and 65.0%, respectively. Patients undergoing mitral valve interventions experienced less frequent heart failure (HF) rehospitalization compared to those with medical therapy alone (18.2% vs. 42.0%, p < 0.01). Mitral valve intervention was associated with a lower risk of HF rehospitalization (HR 0.36 [0.18-0.74]) and an improved New York Heart Association class (p < 0.01). Most high-risk MR patients can be treated with mitral valve interventions. However, approximately 10% remained on medical therapy alone and were considered as unsuitable for current transcatheter technologies. Mitral valve intervention was associated with a lower risk of HF rehospitalization and improved functional status.

Longitudinal Outcomes Following Surgical Repair of Primary Mitral Regurgitation

Degenerative mitral valve (MV) disease is the most common cause of organic mitral regurgitation (MR) in developed countries. Surgical mitral valve repair is the gold standard treatment for primary MR. Surgical mitral valve repair is associated with excellent outcomes in terms of survival and freedom from recurrent MR. As well, innovations in surgical repair techniques, including thoracoscopically and robotically assisted approaches, further reduce morbidity. Emerging catheter-based therapies may also provide advantages in select patient groups. Although the outcomes following surgical mitral valve repair are well described in the literature, longitudinal follow-up is heterogenous. Indeed, longitudinal follow-up and long-term data are vital to better advise treatment and counsel patients.

A case report of transcatheter repair of severe functional mitral regurgitation in cardiac amyloidosis

Background

Transcatheter therapy has become an alternative for functional mitral regurgitation (FMR) in patients at high surgical risk. However, the intervention of FMR in cardiac amyloidosis (CA) with transcatheter edge-to-edge repair (TEER) is controversial due to the potential risk of left atrial pressure (LAP) elevation.

Case summary

An 83-year-old woman with repeated heart failure (HF) and severe mitral regurgitation (MR) was referred to our centre for TEER. Pre-procedural transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE) confirmed the degree of MR and a functional aetiology. A peculiar LAP increase in this patient occurred immediately after successful TEER clip implantation and her n-terminal prohormone of brain natriuretic peptide significantly increased post-operatively. The diagnosis of CA was suspected and was subsequently established through endomyocardial biopsy. Aggressive anti-HF therapy was initiated and the patient was discharged after her HF symptoms were relieved. At 6-month follow-up, the patient was still alive and no episode of acute HF was experienced.

Discussion

Severe functional MR in CA treated with TEER has the potential risk of increasing LAP. During the short-term follow-up, TEER appears beneficial for left heart function (reduction of MR) but harmful for right heart function (increase of LAP). CA patients with severe FMR should be carefully evaluated about the benefits and potential harm of TEER intervention.

Lifetime Management of Aortic Stenosis: Transcatheter Versus Surgical Treatment for Young and Low-Risk Patients

Transcatheter aortic valve replacement is now indicated across all risk categories of patients with symptomatic severe aortic stenosis and has been proposed as first line option for the majority of patients >74 years old. However, median age of patients enrolled in the transcatheter aortic valve replacement low-risk trials is 74 years and transcatheter aortic valve replacement has never been systematically investigated in young low risk patients. Although the long-term data in surgical aortic valve replacement in young patients (age <75) are well known, such data remain lacking in transcatheter aortic valve replacement. In the absence of clear guideline recommendations in patients with challenging anatomies (eg, hostile calcium, bicuspid), it is important to know the potential advantages and disadvantages of each treatment and to consider how they might integrate with each other in the lifetime management of such patients. In this review, we discuss current outstanding issues on the management of severe aortic stenosis from a lifetime management perspective, particularly in terms of initial intervention and future reinterventions.

The multidisciplinary management of a mechanical mitral valve thrombosis in pregnancy: a case report and review of the literature

Background

The management of anticoagulation for mechanical heart valves during pregnancy poses a unique challenge. Mechanical valve thrombosis is a devastating complication for which surgery is often the treatment of choice. However, cardiac surgery for prosthetic valve dysfunction in pregnant patients confers a high risk of maternofetal morbidity and mortality.

Case summary

A 39-year-old woman in her first pregnancy at 30 weeks gestation presented to hospital with a mechanical mitral valve thrombosis despite therapeutic anticoagulation with low-molecular-weight heparin. She underwent an emergent caesarean section followed immediately by a bioprosthetic mitral valve replacement. This occurred after careful planning and organization on the part of a large multidisciplinary team.

Discussion

A proactive, rather than reactive, approach to the surgical management of a mechanical valve thrombosis in pregnancy will maximize the chances of successful maternal and fetal outcomes.

Are there differences in cardiothoracic surgery performed by trainees versus fully trained surgeons?

OBJECTIVES

We sought to assess the safety of training in cardiothoracic surgery comparing outcomes of cases performed by trainees versus fully trained surgeons.

METHODS

EmBase, Scopus, PubMed, and OVID MEDLINE were searched in August 2021 independently by two authors. A third author arbitrated decisions to resolve disagreements. Inclusion criteria were articles on cardiothoracic surgery reporting on outcomes for trainees. Studies were assessed for appropriateness as per CBEM criteria. Eight hundred and ninety-two results were obtained, 27 represented best evidence (2-meta-analyses, 1-RCT, and 24 retrospective cohort studies).

RESULTS

In all 474,160 operative outcomes were assessed for 434,535 coronary artery bypass grafting (CABG) (431,329 on-pump vs. 3206 off-pump), 3090 AVR, 1740 MVR/repair, 26,433 mixed, 3565 congenital, and 4797 thoracic procedures. In all 398,058 cases were performed by trainees and 75,943 by consultants. One hundred fifty-nine cases were indeterminate. There were no statistically significant differences in the patients' preoperative risk scores. All studies excluded extreme high-risk patients in emergency setting, patients with poor left ventricular function, and reoperation cases that were undertaken by consultants. There were no differences in cardiopulmonary bypass and clamp times for CABG. Times for valve replacement and repair cases were longer for trainees. There were no differences in the postoperative outcomes including perioperative myocardial infarction, resternotomy for bleeding, stroke, renal failure, intensive therapy unit length of stay, and total length of stay. One study reported no differences on angiographic graft patency at 1 year. There were no differences in in-hospital or midterm mortality out to 5-years.

DISCUSSION

Trainees can perform cardiothoracic surgery in dedicated high-volume units with outcomes comparable to those of fully trained surgeons.

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.

Transcatheter Mitral Valve Repair or Replacement: Competitive or Complementary?

Over the last two decades, transcatheter devices have been developed to repair or replace diseased mitral valves (MV). Transcatheter mitral valve repair (TMVr) devices have been proven to be efficient and safe, but many anatomical structures are not compatible with these technologies. The most significant advantage of transcatheter mitral valve replacement (TMVR) over transcatheter repair is the greater and more reliable reduction in mitral regurgitation. However, there are also potential disadvantages. This review introduces the newest TMVr and TMVR devices and presents clinical trial data to identify current challenges and directions for future research.

Mitral Valve-in-Valve Implant of a Balloon-Expandable Valve Guided by 3-Dimensional Printing

Background

Our goal was to explore the role of 3-dimensional (3D) printing in facilitating the outcome of a mitral valve-in-valve (V-in-V) implant of a balloon-expandable valve.

Methods

From November 2020 to April 2021, 6 patients with degenerated mitral valves were treated by a transcatheter mitral V-in-V implant of a balloon-expandable valve. 3D printed mitral valve pre- and post-procedure models were prepared to facilitate the process by making individualized plans and evaluating the outcomes.

Results

Each of the 6 patients was successfully implanted with a balloon-expandable valve. From post-procedural images and the 3D printed models, we could clearly observe the valve at the ideal position, with the proper shape and no regurgitation. 3D printed mitral valve models contributed to precise decisions, the avoidance of complications, and the valuation of outcomes.

Conclusions

3D printing plays an important role in guiding the transcatheter mitral V-in-V implant of a balloon-expandable valve.

Clinical Trial Registration

ClinicalTrials.gov Protocol Registration System (NCT02917980).

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.

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.

Challenges and future perspectives of transcatheter tricuspid valve interventions: adopt old strategies or adapt to new opportunities?

Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease and is associated with an increased risk of cardiovascular events and death at long-term follow-up. Functional TR accounts for over 90% of TR and is mainly due to annular or right ventricular dilatation. Most often, TR is observed in patients with left-sided valvular heart disease (with or without previous surgical correction) and pulmonary hypertension. Isolated TR is less frequent, though burdened by high surgical mortality. This, together with an incomplete understanding of the disease, has brought to a significant undertreatment in spite of the growing evidence of the impact of severe TR on mortality. Moreover, uncertainties about the appropriate timing for intervention and the predictors of procedural success have contributed to limit TR treatment. Transcatheter tricuspid valve replacement or repair interventions represent novel and less invasive alternatives to surgery and have shown early promising results. The purpose of this review is to provide a complete and updated overview of TR pathology with a special focus on current percutaneous treatment options, future challenges and directions.

Transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation: insights from the multi-center MITRA-TUNE registry

BACKGROUND

A-FMR is considered a specific sub-type of secondary MR in patients with atrial fibrillation (AF) and preserved left ventricle ejection fraction (LVEF). Aim of the study was to investigate the acute and mid-term outcomes of transcatheter edge-to-edge mitral valve repair (TMVr) with the MitraClip in atrial functional mitral regurgitation (A-FMR).

METHODS

The study included patients with A-FMR and concomitant AF who underwent to the MitraClip at 7 Italian Centers. Aim of the study was to assess the safety, efficacy and mid-term cardiovascular outcomes.

RESULTS

After reviewing 1153 patients with FMR treated with TMVr from 2009 to 2021, 87 patients (median age 81 years, 61% female) with A-FMR were identified. Technical success was achieved in 97%, 30-day device success in 83% and 30-day procedural success in 80%. All-cause death at 30-day was 5%. Estimated two-year freedom from all-cause death and cardiac death was 60% and 77%, respectively, whereas freedom from all-cause death/heart failure hospitalization was 55%. Residual MR ≤ 2+ was encountered in 89% (n = 47/53) and improvement in NYHA class I/II in 79% (n = 48/61). Post-procedural MR ≥ 2+ (HR 5.400, CI 1.371-21.268) and inter-commissural annular diameter ≥ 35 mm (HR 4.159, CI 1.057-16.363) were independent predictors of all-cause death/heart failure hospitalization during the follow-up. Positive reverse remodeling of left atrium and mitral annular dimensions occurred after TMVr during the follow-up.

CONCLUSIONS

MitraClip resulted to be a safe and effective option to treat A-FMR in elderly patients.