The EVEREST II Trial: design and rationale for a randomized study of the evalve mitraclip system compared with mitral valve surgery for mitral regurgitation

Preprocedural transthoracic echocardiography for predicting outcomes of transcatheter edge-to-edge repair for chronic primary mitral regurgitation

INTRODUCTION AND OBJECTIVES

Limited data exist on the prognostic usefulness of transthoracic echocardiography preceding MitraClip for chronic primary mitral regurgitation (MR). We evaluated the predictive ability of transthoracic echocardiography in this setting.

METHODS

A total of 410 patients (median age, 83 years, 60.7% males) were included in the study. The primary outcome was the 1-year composite of all-cause mortality or heart failure hospitalization. Secondary endpoints encompassed individual elements of the primary outcome, the persistence of significant functional impairment or above-moderate MR at 1 year, and above-mild MR at 1-month.

RESULTS

The only parameter associated with the risk of the primary outcome was a ventricular end systolic diameter index of ≥2.1 cm/m2, corresponding to the cohort's 4th quartile (HR, 2.44; 95%CI, 1.09-4.68; P=.022). Concurrently, higher left atrial volume index (LAVi) and a mid-diastolic medial-lateral mitral annular diameter (MAD) equal to or above the cohort's median of 32.2mm were linked to a higher probability of death and heart failure hospitalization, respectively. LAVi of ≥ 60mL/m2, above-mild mitral annular calcification, and above-moderate tricuspid regurgitation conferred higher odds of functional class III-IV or above-moderate MR persistence. All variables except LAVi and MAD, as well as indexed mid-diastolic medial-lateral MAD of ≥ 20.2mm/m2 and mitral effective regurgitant orifice area of ≥ 0.40 cm2, were associated with greater-than-mild MR at 1 month.

CONCLUSIONS

Preprocedural increased indexed left heart dimensions, mainly left ventricular end-systolic diameter index, MAD, mitral annular calcification, mitral effective regurgitant orifice area, and tricuspid regurgitation mark a less favorable course post-MitraClip for chronic primary MR.

3-Year Outcomes for Degenerative Mitral Regurgitation Repair in a Medicare Population

OBJECTIVE

Mitral valve repair (MVr) has become the standard therapy for degenerative mitral regurgitation (DMR), but real-world late mortality, reintervention, and readmission data are lacking. This study estimates MVr outcomes for DMR to 3 years in the Medicare fee-for-service population.

METHODS

There were 4,219 DMR patients older than 65 years undergoing MVr within the Medicare 100% standard analytic file from October 2015 to December 2018 who were evaluated. Outcomes were analyzed for isolated MVr patients (n = 2,433) and patients undergoing MVr with certain concomitant procedures: MVr + tricuspid valve surgery (TVS; n = 619), MVr + cardiac ablation (CA; n = 540), and MVr + left atrial appendage closure (n = 627). Outcomes over a 3-year period included all-cause mortality, reintervention, rehospitalization, and common complications. All outcomes were modeled with adjustments for patient demographics and comorbid conditions.

RESULTS

The average age for all patients was 71.9 ± 5.2 years. Adjusted all-cause mortality and MV reintervention (surgery or transcatheter) at 3 years for the primary cohort of isolated MVr was 3.5% and 1.6%, respectively. Directionally higher mortality at 3 years was observed in patients with concomitant TVS or CA. All-cause readmission and cardiac readmission for isolated MVr was 37.0% and 14.1%, with the highest rates for those with concomitant TVS or CA. Acute kidney injury and stroke/transient ischemic attack were the most common adverse events over 3 years for all patients.

CONCLUSIONS

The 3-year mortality and reintervention rates in Medicare patients undergoing degenerative MVr are low. Those undergoing concomitant TVS or CA had directionally higher mortality and cardiac readmission rates. These results help refine outcome benchmarks as new transcatheter MVr procedures continue to emerge.

Mitral transcatheter edge-to-edge repair: patient selection, current devices, and clinical outcomes

INTRODUCTION

Over the last two decades, mitral transcatheter edge-to-edge repair (M-TEER) has become a safe and effective therapy for severe mitral regurgitation in patients deemed at high surgical risk.

AREAS COVERED

This review aims to encompass the most relevant and updated evidence in the field of M-TEER from its inception, focusing on clinical and anatomical features for proper patient and device selection.

EXPERT OPINION

Growing operator experience and device iterations have resulted in improved clinical outcomes and an expansion of the therapy to patients with complex anatomies and clinical scenarios. Future investigations are warranted to determine the best management options and the most suitable device for every patient with MR.

Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

Advancements in MitraClip Intervention for Mitral Regurgitation: A Comprehensive Review and Comparative Analysis of Clinical Trials

This comprehensive review explores the evolution and clinical impact of MitraClip intervention in the management of mitral regurgitation. Mitral regurgitation results from dysfunction in the mitral valve (MV) apparatus. The MitraClip Clip Delivery System was approved by the Food and Drug Administration (FDA) in 2013. The discussion delves into the procedural foundation of MitraClip intervention, primarily based on Alfieri's technique of edge-to-edge leaflet approximation. As highlighted by key clinical trials, including Endovascular Valve Edge-to-Edge Repair (EVEREST) II Trial, Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) Trial, and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation (MITRA-FR) trial, the efficacy and safety of MitraClip were evaluated in comparison to surgical interventions and guideline-directed medical therapy. Notably, the COAPT demonstrated significant benefits in reducing all-cause mortality and heart failure hospitalization, while the MITRA-FR presented contrasting results, emphasizing the importance of patient selection. An analysis of the EVEREST II trial underscores MitraClip's potential to achieve comparable outcomes to surgical intervention, emphasizing its role in reducing mitral regurgitation and improving clinical status. However, limitations and complications, such as device-related issues and the potential impact on future MV surgery, are discussed. The study also explores the evolving landscape of MV interventions, reflecting advancements and the growing acceptance of MitraClip. In conclusion, the MitraClip device represents a significant advancement in the treatment of mitral regurgitation. The data presented highlights its promising results in terms of reduced hospitalization rates, improved in-hospital mortality, and enhanced quality of life for patients. However, challenges remain, and careful consideration of patient selection and underlying pathology is crucial in determining the optimal treatment approach. Ongoing research and clinical experience will continue to refine our understanding of MitraClip's role in the evolving landscape of MV interventions.

Transcatheter Mitral Valve Replacement in Patients with Mitral Annular Calcification: A Review

Mitral annular calcification (MAC) is a progressive degenerative calcification of the mitral valve (MV) that is associated with mitral stenosis, regurgitation or both. Patients with MAC are poor candidates for MV surgery because of technical challenges and high peri-operative mortality. Transcatheter MV replacement (TMVR) has emerged as an option for such high surgical risk patients. This has been described with the use of the SAPIEN transcatheter heart valve (valve-in-MAC) and dedicated TMVR devices. Careful anatomic assessment is important to avoid complications of TMVR, such as left ventricular outflow tract obstruction, valve migration, embolization and paravalvular mitral regurgitation. In this review, we discuss the pathology, importance of preprocedural multimodality imaging for optimal patient selection, clinical outcomes and complications associated with TMVR in patients with MAC.

Novel 3D Echocardiographic Technique for Mitral Calcium Mapping

Mitral annular calcification (MAC) is a common chronic degenerative process of the mitral valve fibrous support ring. MAC increases the risk of mitral valve dysfunction, all-cause and cardiovascular mortality, and worse outcomes in cardiac interventions. Echocardiography represents the first imaging modality for MAC assessment, but it has low specificity compared to cardiac CT in terms of distinguishing between calcium and dense collagen. Novel three-dimensional transesophageal maximal intensity projection (MIP) mapping allows for the real-time MAC distribution and depth visualization of the cardiac anatomy and represents a useful and promising tool for pre-procedural assessment and intra-procedural guidance of cardiac interventions.

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.

Mitral valve transcatheter edge-to-edge repair

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, results in reduced quality of life, heart failure, and increased mortality. Mitral valve transcatheter edge-to-edge repair (M-TEER) has matured considerably as a non-surgical treatment option since its commercial introduction in Europe in 2008. As a result of major device and interventional improvements, as well as the accumulation of experience by the interventional cardiologists, M-TEER has emerged as an important therapeutic strategy for patients with severe and symptomatic MR in the current European and American guidelines. Herein, we provide a comprehensive up-do-date overview of M-TEER. We define preprocedural patient evaluation and highlight key aspects for decision-making. We describe the currently available M-TEER systems and summarise the evidence for M-TEER in both primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR). In addition, we provide recommendations for device selection, intraprocedural imaging and guiding, M-TEER optimisation and management of recurrent MR. Finally, we provide information on major unsolved questions and "grey areas" in M-TEER.

MitraClip: a review of its current status and future perspectives

Mitral regurgitation (MR), among the most common valvular heart diseases, is closely associated with heart failure and worse clinical outcomes. Surgical repair or replacement as an intervention for MR is deemed too high risk in patients who are elderly or have multiple comorbidities; thus, nearly half of all patients with severe symptomatic MR are not referred for surgical therapy. MitraClip, a transcatheter mitral valve repair system for MR that mimics the Alfieri surgical edge-to-edge technique for mitral valve repair, was developed in the late 1990s. After clinical trials demonstrated its safety and efficacy, it received approval for clinical use, particularly for aging and inoperable or high-risk patients for heart surgery in Europe, the US, and Japan. Since the start of its clinical use, randomized clinical trials (RCTs) have optimized patient selection, and the latest generation MitraClip can increase procedural success, even in patients with challenging mitral valve anatomy. Therefore, here, we review evidence from clinical trials and RCTs and discuss optical patient selection and future perspectives for the MitraClip.

Patient Selection for Mitral Transcatheter Edge-to-Edge Repair

Mitral regurgitation (MR) is one of the most common valvular heart diseases, with many patients remaining non-suitable for surgical interventions. Transcatheter edge-to-edge repair (TEER) is a rapidly evolving procedure that allows safe and effective reduction of MR in high-risk patients. However, adequate patient selection through clinical assessment and imaging modalities remains a key factor for procedural success. In the following review, we highlight recent developments in TEER technologies that are expanding the target population and currently available imaging modalities that allow detailed evaluation of the mitral valve and surrounding structures for optimal patient selection.

MitraClip™ implantation plus left atrial appendage occlusion in a hereditary hemorrhagic telangiectasia patient

Hereditary hemorrhagic telangiectasia is regarded as a high hemorrhagic risk condition, and the management of anticoagulation and heart surgery in these patients can be challenging. The authors describe a combined percutaneous treatment of mitral regurgitation and left atrial appendage occlusion in a patient affected by hereditary hemorrhagic telangiectasia and atrial fibrillation, supporting the safety and feasibility of the procedure and the optimal short-term outcome.

Transcatheter Edge-to-Edge Repair for Acute Mitral Regurgitation due to Postinfarction Papillary Muscle Rupture

Background

Early case reports have suggested that transcatheter edge-to-edge repair (TEER) with the MitraClip for the treatment of acute mitral regurgitation (MR) due to post-infarction papillary muscle rupture (PMR) may be an alternative for patients at prohibitive surgical risk. However, data on consecutive patients treated for this condition is lacking.

Methods

To define the procedural characteristics, medication use, hemodynamic parameters, and imaging data, we present 5 consecutive patients with acute MR from postinfarction PMR treated with TEER at Scripps Memorial Hospital La Jolla between June 2018 and November 2020.

Results

Successful reduction of MR and improved hemodynamics were achieved in all cases. Despite the procedural success, only 1 of the 5 patients survived until hospital discharge.

Conclusion

TEER may be an effective treatment for acute MR due to postinfarction PMR to reduce MR and improve hemodynamics. Survival to discharge was infrequent, suggesting that TEER may be appropriate only in selected patients.

Treatment of secondary mitral regurgitation by transcatheter edge-to-edge repair using MitraClip

Transcatheter edge-to-edge repair (TEER) is becoming the standard invasive treatment for ventricular functional mitral regurgitation (MR). It is necessary to determine the severity of MR before treatment with MitraClip; however, the severity of secondary MR is usually underestimated compared with that of primary MR and varies temporally. Therefore, to accurately determine the severity of MR, it is important to correctly use the algorithm of the guidelines for valvular heart disease and aggressively perform stress echocardiography. Before performing TEER, the difficulty of the procedure should be evaluated. First, morphological features that make TEER unsuitable, such as cleft of the mitral leaflet, mitral stenosis (MS), or perforation of the mitral leaflet, should be checked. The mitral valve orifice area, transmitral valve pressure gradient, coaptation depth, coaptation length, and posterior leaflet length should be measured to determine the difficulty of the procedure based on the inclusion criteria of Endovascular Valve Edge-to-Edge Repair Study II and the German consensus. After MitraClip implantation, in addition to assessing the severity of MS and residual MR, the pulmonary venous flow pattern and stroke volume should be evaluated to comprehensively assess whether TEER improves the hemodynamics. MitraClip has also been used to treat atrial functional MR, another type of secondary MR. Several reports suggest that MitraClip is effective for atrial functional MR; however, evidence is still being accumulated.

Mitral Valve Prolapse-The Role of Cardiac Imaging Modalities

Mitral valve prolapse (MVP) is the most common nonischemic mitral regurgitation etiology and mitral abnormality requiring surgery in the Western world. There is an increasing awareness that pathological findings in MVP are not confined to the valve tissue; rather, it is a complex disease, involving the mitral valve apparatus, cardiac hemodynamics, and cardiac structure. Imaging has played a fundamental role in the understanding of the diagnosis, prevalence, and consequences of MVP. The diagnosis of MVP by imaging is based upon demonstrating valve leaflets ascending into the left atrium through the saddle-shaped annulus. Transthoracic and transesophageal echocardiography are the primary modalities in the diagnosis and assessment of MVP patients and must include careful assessment of the leaflets, annulus, chords, and papillary muscles. High-spatial-resolution imaging modalities such as cardiac magnetic resonance images and cardiac computed tomography play a secondary role in this regard and can demonstrate the anatomical relation between the mitral valve annulus and leaflet excursion for appropriate diagnosis. Ongoing development of new methods of cardiac imaging can help us to accurately understand the mechanism, diagnose the disease, develop an appropriate treatment plan, and estimate the risk for sudden death. Recently, several new observations with respect to prolapse have been derived from cardiac imaging including three-dimensional echocardiography and tissue-Doppler imaging. The aim of this article is to present these new imaging-derived insights for the diagnosis, risk assessment, treatment, and follow-up of patients with MVP.

Transcatheter Treatment of Mitral Regurgitation

Mitral valve disease, and in particular mitral regurgitation, is a common clinical entity. Until recently, surgical repair and replacement were the only therapeutic options available, leaving many patients untreated mostly due to excessive surgical risk. Over the last number of years, huge strides have been made regarding percutaneous, catheter-based solutions for mitral valve disease. Transcatheter repair procedures have most commonly been used, and in recent years there has been exponential growth in the number of devices available for transcatheter mitral valve replacement. Furthermore, the evolution of these devices has resulted in both smaller delivery systems and a shift towards transeptal access, negating the need for surgical incisions. In line with these advancements, and clinical trials demonstrating promising outcomes in carefully selected cases, recent guidelines have strengthened their recommendations for these devices. It is appropriate, therefore, to now review the current transcatheter repair and replacement devices available and the evidence for their use.

Anatomical and Technical Predictors of Three-Dimensional Mitral Valve Area Reduction After Transcatheter Edge-To-Edge Repair

BACKGROUND

Among current transcatheter therapies for the treatment of mitral regurgitation, the MitraClip (MC; Abbott Vascular, Abbott Park, IL) system is the most commonly used. MitraClip implantation is usually contraindicated in patients with a mitral valve area (MVA) < 4.0 cm². However, little is known about the real impact of MC implantation on MVA. Our goal was to investigate the factors influencing MVA reduction and derive the minimal MVA required to prevent the development of a clinically significant mitral stenosis (MVA < 1.5 cm²) in different clinical scenarios.

METHODS

Using three-dimensional data sets, the annulus and leaflet anatomy and MVA before clip implantation (MVA_BC) were assessed. After each MC implant (NTR or XTR), the relative MVA reduction and the absolute residual MVA were measured and their predictors evaluated.

RESULTS

The present analysis included 116 patients. An MC XTR was the first device implanted in 50% of the subjects, and 53% were treated with a single implant. The MVA reduction following one XTR was 57% ± 7% versus 52% ± 8% after one NTR (P = .001). A lower MVA reduction was observed when the MC was placed commissural/central versus paracentral (50% ± 8% vs 57% ± 7%, P < .0001). After a second device, the additional MVA reduction was higher when creating a triple-compared with a double-orifice morphology (34% ± 11% vs 25% ± 9%, P = .001). The MVA after one MC correlated with MVA_BC as well as with the clip type and position (r = 0.91, P < .0001). The MVA_BC, orifice morphology, and first device position predicted MVA after two implants (r = 0.82, P < .0001). Based on the mathematical relationship between these parameters, the minimal MVA_BC needed in eight different clinical scenarios was summarized in a decision algorithm: the values ranged from 3.5 to 4.7 cm² for one and 4.5 to 6.3 cm² for two MC strategies.

CONCLUSIONS

The minimal native MVA preventing clinically relevant MS after transcatheter edge-to-edge repair is predicted by the number and location of clip(s), orifice morphology, and device type. Based on these parameters, an algorithm has been derived to optimize patient selection and preprocedural planning.

Transcatheter mitral valve therapies: State of the art

Mitral regurgitation (MR) is one of the most prevalent valvular pathologies in the developed world. There continues to be a growing population of aging patients with MR who may be too high risk for surgical management. The rapid adoption and remarkable success of transcatheter aortic valve replacement (TAVR) generated enthusiasm for transcatheter mitral valve therapies; however, the complex anatomy and pathophysiology of the mitral valve confers several unique challenges for a fully percutaneous approach. Nevertheless, several devices are under development and in various phases of preclinical or clinical testing, both for transcatheter mitral valve replacement and repair. MitraClip (Abbott Vascular), which has received FDA approval, is the most established percutaneous repair strategy and has been performed in over 80,000 patients as of 2019. The following article serves as a review of the available and upcoming devices for the various etiologies of mitral valvular disease, as well as the unique challenges and potential complications of transcatheter mitral valve intervention.

MitraClip to Treat Severe Ischemic Mitral Regurgitation During Impella CP Support in a 70-Year-Old Woman

Acute mitral regurgitation is a life-threatening complication of acute myocardial infarction. We present the case of a 70-year-old woman who had acute myocardial infarction complicated by severe mitral regurgitation and cardiogenic shock. Although current guidelines recommend mitral valve surgery for such patients, surgery often carries prohibitive risk of morbidity and mortality. Thus, in certain patients, percutaneous repair may be the only viable treatment option. In this case, we used a 3-step percutaneous approach involving coronary artery revascularization with a drug-eluting stent in the left circumflex coronary artery, mechanical circulatory support with an Impella CP pump for cardiogenic shock, and mitral valve repair with the MitraClip system for severe mitral regurgitation. After successful intervention, our patient regained hemodynamic stability and showed clinical improvement at one-month follow-up.

Understanding the Merits and Drawbacks of Noninferiority Trials in Cardiovascular Medicine

A noninferiority trial is designed to show that the new treatment is not unacceptably worse than the standard treatment by more than a predefined noninferiority margin. These trials are typically performed when standard placebo-controlled trials are considered to be unethical or impractical and the new treatment offers advantages over the existing standard treatment in terms of safety, convenience, or cost. Given that noninferiority trials are being performed with increasing frequency in cardiovascular applications, it is important to understand their complex trial design and analysis. This narrative review aims to provide readers with a detailed perspective on the goals, characteristics, design, and analysis of noninferiority trials. Trials designed to show noninferiority require an appropriate reference population, a proven standard treatment and dose, an appropriate margin of noninferiority that is statistically justifiable (based on historical placebo-controlled trials evaluating standard treatment effect) and clinically reasonable (choosing the fraction of the effect of the standard drug that should be "preserved" by the new drug), a high level of adherence to treatment, and adequate statistical power to reliably conclude that a treatment is truly noninferior and therefore effective. The merits and pitfalls of noninferiority trials, with representative contemporary cardiovascular clinical trials in interventional cardiology, cardiac surgery, and atrial fibrillation management as exemplars, are described. The key issues that challenge the design, conduct, analysis, interpretation, and implementation of these trials are discussed, and a variety of ways to identify and mitigate key errors are recommended to allow for optimal evaluation of noninferiority trials conducted in cardiovascular medicine.

Complete Atrioventricular Block: A Rare Complication of MitraClip Implantation

MitraClip (Abbott Vascular, Inc., Santa Clara, California) has emerged as a viable alternative for treatment of symptomatic severe mitral regurgitation. Conduction abnormalities are not a known complication of this procedure. We report a case of complete heart block without a ventricular escape rhythm immediately following MitraClip placement near the medial leaflets (A3-P3) in a patient with underlying trifascicular block. (Level of Difficulty: Intermediate.).

The role of CT in planning percutaneous structural heart interventions: Where to measure and why

As research continues to demonstrate successes in the use of percutaneous trans-vascular techniques in structural heart intervention, both the subspecialty trained and non-subspecialty trained cardiac imager find themselves performing and reporting larger amounts of information regarding cardiovascular findings. It is therefore imperative that the imager gains understanding and appreciation for how these various measurements are obtained, as well as their implication in a patient's care. Cardiac gated computed tomography (CT) has solidified its role and ability at providing high resolution images that can be used to obtain the key measurements used in structural heart intervention planning. This manuscript aims to provide an overview of what measurements are necessary to report when interpreting CT examinations purposed for structural heart intervention. This includes a review on indications and brief discussion on complications related to these procedures.

Speckle tracking echocardiography in primary mitral regurgitation: should we reconsider the time for intervention?

Thanks to the improvement in mitral regurgitation (MR) diagnostic and therapeutic management, with the introduction of minimally invasive techniques which have considerably reduced the individual surgical risk, the optimization of the timing for MR “open” or percutaneous surgical treatment has become a main concern which has highly raised scientific interest. In fact, the current indications for intervention in MR, especially in asymptomatic patients, rely on echocardiographic criteria with high severity cut-offs that are fulfilled only when not only mitral valve apparatus but also the cardiac chambers’ structure and function are severely impaired, which results in poor benefits for post-operative clinical outcome. This led to the need of new indices to redefine the optimal surgical timing in these patients. Speckle tracking echocardiography provides early markers of cardiac dysfunction due to subtle myocardial impairment; therefore, it could offer pivotal information in this setting. In fact, left ventricular and left atrial strains have already shown evidence about their usefulness in recognizing MR impact not only on symptoms and quality of life but also on cardiovascular events and new-onset atrial fibrillation in these patients. Moreover, right ventricular strain could be used to identify those patients with advanced cardiac damage and different grades of right ventricular dysfunction, which entails higher risks for cardiac surgery that could overweigh surgical benefits. This review aims to describe the importance of reconsidering the timing of intervention in MR and to analyze the potential additive value of speckle tracking echocardiography in this clinical setting.

Three-Dimensional Imaging and Dynamic Modeling of Systolic Anterior Motion of the Mitral Valve

Left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy (HCM) is often caused by systolic anterior motion (SAM) of the mitral valve caused by the interplay between increased left ventricular (LV) wall thickness and an abnormal mitral valve anatomy and geometry. Three-dimensional (3D) echocardiographic imaging of the mitral valve has revolutionized the practice of cardiology, paving the way for new methods to see and treat valvular heart disease. Here we present the novel and incremental value of 3D transesophageal echocardiography (TEE) of SAM visualization. This review first provides step-by-step instructions on acquiring and optimizing 3D TEE imaging of SAM. It then describes the unique and novel findings using standard 3D TEE rendering as well as dynamic mitral valve modeling of SAM from 3D data sets, which can provide a more detailed visualization of SAM features. The findings include double-orifice LVOT caused by the residual leaflet, the dolphin smile phenomenon, and delineation of SAM width. Finally, the review discusses the essential role of 3D TEE imaging for preprocedural assessment and intraprocedural guidance of surgical and novel percutaneous treatments of SAM.

Conceiving MitraClip as a tool: percutaneous edge-to-edge repair in complex mitral valve anatomies

Improvements in procedural technique and intra-procedural imaging have progressively expanded the indications of percutaneous edge-to-edge technique. To date in higher volume centres and by experienced operators MitraClip is used for the treatment of complex anatomies and challenging cases in high risk-inoperable patients. This progressive step is superimposable to what observed in surgery for edge-to-edge surgery (Alfieri's technique). Moreover, the results of clinical studies on the treatment of patients with high surgical risk and functional mitral insufficiency have confirmed that the main goal to be achieved for improving clinical outcomes of patients with severe mitral regurgitation (MR) is the reduction of MR itself. The MitraClip should therefore be considered as a tool to achieve this goal in addition to medical therapy. Nowadays, evaluation of patient's candidacy to MitraClip procedure, discussed in local Heart Team, must take into account not only the clinical features of patients but even the experience of the operators and the volume of the centre, which are mostly related to the probability to achieve good procedural results. This 'relative feasibility' of challenges cases by experienced operators should always been taken into account in selecting patients for MitraClip. Here, we present a review of the literature available on the treatment of complex and challenging lesions.

Cerebrovascular events after transcatheter mitral valve interventions: a systematic review and meta-analysis

Objective

Current guidelines support the use of transcatheter mitral valve interventions to treat some selected high-risk patients with significant mitral valvulopathy. As with any other interventional cardiac procedure, concerns have been raised about cerebrovascular event. The aim of this systematic review and meta-analysis was to determine the incidence of cerebrovascular events following (1) transcatheter mitral valve edge-to-edge repair with mitral valve clip and (2) transcatheter mitral valve replacement (TMVR).

Methods

We conducted a systematic review of studies reporting the cerebrovascular adverse events after transcatheter mitral valve edge-to-edge repair and TMVR procedures. The primary endpoint was the incidence of cerebrovascular events as defined by the Mitral Valve Academic Research Consortium. An event that occurred within 30 days or during index hospitalisation was defined as periprocedural; otherwise it was defined as non-periprocedural. This study was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Aggregated study-level data were pooled using a random effect model. The quality of each study was appraised with the Hawker checklist, a method of systematically reviewing research from different paradigms.

Results

Sixty studies totalling 28 155 patients undergoing edge-to-edge repair with mitral valve clip were included in the analysis. Periprocedural stroke and non-periprocedural stroke rates were 0.9% (95% CI 0.6 to 1.1) and 2.4% (95% CI 1.6 to 3.2), respectively. For TMVR procedures, 26 studies including 1910 patients were analysed. The estimated periprocedural stroke incidence was 1% (95% CI 0.5 to 1.8) compared with 7% (95% CI 0.8 to 18.5) for non-periprocedural stroke.

Conclusions

Transcatheter mitral valve interventions are associated with low rates of cerebrovascular events. The exact mechanisms of these complications are still poorly understood given the relative paucity of good quality data.

Trial registration number

CRD42019117257.

Percutaneous mitral valve repair: the necessity to redefine secondary mitral regurgitation

Interest in percutaneous mitral valve repair has increased during recent years. This is mainly driven by the significant number of patients being declined for mitral valve surgery because of a high risk of surgery-related complications or death. In this subset of patients, percutaneous edge-to-edge repair using the MitraClip device (Abbott, Menlo Park, CA, USA) has become an established treatment option, proven to be safe, efficient and associated with improved functional status. In contrast to primary mitral regurgitation (MR), clinical outcomes after mitral valve surgery appear to be less favourable as regards secondary MR due to heart failure. In the MITRA-FR and COAPT trials, patients with moderate to severe and severe secondary MR with reduced left ventricular function received either medical treatment (control group) or MitraClip implantation plus medical treatment (device group). Results were conflicting, with only the COAPT trial showing better clinical outcomes in the device group. However, both trials are now seen as complementary and provide useful information especially regarding patient selection for MitraClip therapy. The goal of this review is to delineate which subset of patients with secondary MR will potentially benefit from percutaneous mitral valve repair.

Acute Mitral Regurgitation and Transcatheter Mitral Valve Repair in an Emergency Case: Focus on the Mechanical Disorder of Mitral Valve Complex

Acute mitral regurgitation is an uncommon, challenging disease that requires emergent care and proper management. To evaluate its etiology, echocardiography is essential. However, echocardiography findings in these patients are often different from that of chronic mitral regurgitation owing to the acute elevation of left atrial and pulmonary artery pressure derived from the small left ventricle and atrium with low compliance. Although surgical correction is usually required owing to the hemodynamic instability, many patients are considered to be at high surgical risk. Transcatheter mitral valve repair using MitraClip (Abbott Vascular, Santa Clara, CA) may be a solution as a bail-out therapy.

One-Year Outcomes After MitraClip for Functional Mitral Regurgitation

BACKGROUND

Secondary mitral regurgitation (SMR) occurs in the absence of organic mitral valve disease and may develop as the left ventricle dilates or remodels or as a result of leaflet tethering with impaired coaptation, most commonly from apical and lateral distraction of the subvalvular apparatus, with late annular dilatation. The optimal therapy for SMR is unclear. This study sought to evaluate the 1-year adjudicated outcomes of all patients with SMR undergoing the MitraClip procedure in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) Investigational Device Exemption program, which is comprised of the randomized clinical trial, the prospective High-Risk Registry, and the REALISM Continued Access Registry (Multicenter Study of the MitraClip System).

METHODS

Patients with 3+/4+ SMR enrolled in EVEREST II were stratified by non-high surgical risk (non-HR) and high surgical risk (HR) status (defined as Society of Thoracic Surgeons risk of mortality ≥12% or predefined risk factors). Clinical, echocardiographic, and functional outcomes at 1 year were evaluated.

RESULTS

A total of 616 patients (482 HR, 134 non-HR; mean age, 73.3±10.5 years; Society of Thoracic Surgeons risk, 10.2±6.9%) with SMR underwent the MitraClip procedure. At baseline, 80.5% of patients were in New York Heart Association class III/IV. Major adverse events at 30 days included death (3.6%), stroke (2.3%), and renal failure (1.5%). At discharge, 88.8% had MR ≤2+. At 1 year, there were 139 deaths, and the Kaplan-Meier estimate of freedom from mortality was 76.8%. The majority of surviving patients (84.7%) remained with MR ≤2+ and New York Heart Association class I/II (83.0%). Kaplan-Meier survival at 1 year was 74.1% in HR patients and 86.4% in non-HR patients ( P=0.0175). At 1 year, both groups achieved comparable MR reduction (MR ≤2+, 84.0% versus 87.0%) and improvement in left ventricular end-diastolic volume (-8.0 mL versus -12.7 mL), whereas New York Heart Association class I/II was found in 80.1% versus 91.8% ( P=0.008) of HR and non-HR patients, respectively. In HR patients, the annualized rate of heart failure hospitalizations decreased from 0.68 to 0.46 in the 12 months before to 12 months after the procedure ( P<0.0001).

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip in patients with secondary MR is associated with acceptable safety, reduction of MR severity, symptom improvement, and positive ventricular remodeling.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov . Unique identifiers: NCT00209274, NCT01940120, and NCT01931956.

Successful MitraClip for severe rheumatic mitral regurgitation: a case report

Background

Anatomical exclusion criteria for the MitraClip procedure have included rheumatic heart disease (RHD) involving the mitral valve. This was primarily because RHD is typically associated with mitral stenosis (MS).

Case summary

We report the case of an 85-year-old male who had recurrent heart failure admissions from severe rheumatic mitral regurgitation (MR). This was successfully treated with the MitraClip system.

Discussion

Our case demonstrated the possibility of rheumatic MR being treated by the MitraClip system in appropriately selected patients. Careful examination of the mechanism of MR to determine suitability for MitraClip must be done as well as exclusion of significant MS.

Single-center five-year outcomes after interventional edge-to-edge repair of the mitral valve

BACKGROUND

The MitraClip procedure was established as a therapeutic alternative to mitral valve surgery for symptomatic patients with severe mitral regurgitation (MR) at prohibitive surgical risk. In this study, the aim was to evaluate 5-year outcomes after MitraClip.

METHODS

Consecutive patients undergoing the MitraClip system were prospectively included. All patients underwent clinical follow-up and transthoracic echocardiography.

RESULTS

Two hundred sixty-five patients (age: 81.4 ± 8.1 years, 46.7% female, logistic EuroSCORE: 19.7 ± 16.7%) with symptomatic MR (60.5% secondary MR [sMR]). Although high procedural success of 91.3% was found, patients with primary MR (pMR) had a higher rate of procedural failure (sMR: 3.1%, pMR: 8.6%; p = 0.04). Five years after the MitraClip procedure, the majority of patients presented with reduced symptoms and improved functional capacity (functional NYHA class: p = 0.0001; 6 minutes walking test: p = 0.04). Sustained MR reduction (≤ grade 2) was found in 74% of patients, and right ventricular (RV) function was significantly increased (p = 0.03). Systolic pulmonary artery pressure (sPAP) was significantly reduced during follow-up only in sMR patients (p = 0.05, p = 0.3). Despite a pronounced clinical and echocardiographical amelioration and low interventional failure, 5-year mortality was significantly higher in patients with sMR (p = 0.05). The baseline level of creatinine (HR: 0.695), sPAP (HR: 0.96) and mean mitral valve gradient (MVG) (HR: 0.82) were found to be independent predictors for poor functional outcome and mortality.

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip system showed low complication rates and sustained MR reduction with improved RV function and sPAP 5 years after the procedure was found in all patients, predominantly in patients with sMR. Despite pronounced functional amelioration with low procedure failure, sMR patients had higher 5-year mortality and worse outcomes. Baseline creatinine, MVG, and sPAP were found to be independent predictors of poor functional outcomes and 5-year mortality.

Transcatheter or surgical repair for degenerative mitral regurgitation in elderly patients: A propensity-weighted analysis

OBJECTIVE

To compare the outcomes of MitraClip and surgical mitral repair in low-intermediate risk elderly patients affected by degenerative mitral regurgitation (DMR).

METHODS

We retrospectively selected patients aged ≥75 years, with Society of Thoracic Surgeons Predicted Risk Of Mortality (STS-PROM) <8%, submitted to MitraClip (n = 100) or isolated surgical repair (n = 206) for DMR at 2 centers between January 2005 and May 2017. To adjust for baseline imbalances, we used a propensity score model for average treatment effect on survival.

RESULTS

After weighting, MitraClip showed fewer postoperative complications (P < .05) but increased residual mitral regurgitation (MR) ≥2 (27.0% vs 2.8%, P < .001) compared with surgery. One-year survival was greater after MitraClip compared with surgery (97.6% vs 95.3%, hazard ratio [HR], 0.09; confidence interval [CI], 0.02-0.37, P = .001), whereas 5-year survival was lower (34.5% vs 82.2% respectively, HR, 4.12; CI, 2.31-7.34, P < .001). Greater STS-PROM (HR, 1.18; CI, 1.12-1.24, P < .001) and MR ≥3+ recurrence (HR, 2.18; CI, 1.07-4.48, P = .033) were associated with reduced survival. 5-year MR ≥3+ was more frequent after MitraClip compared with surgery: 36.9% versus 3.9%, odds ratio, 11.4; CI, 4.40-29.68, P < .001.

CONCLUSIONS

In elderly patients affected by DMR and STS-PROM <8%, the average effect of MitraClip resulted in lower acute postoperative complications and improved 1-year survival compared with surgery. However, MitraClip was associated with greater MR recurrence and reduced survival beyond 1 year. Long-term survival was impaired by patients' greater risk profile and MR recurrence. Early results are promising, but in the setting of operable patients with life expectancy beyond 1 year, the quality bar for transcatheter mitral repair needs to be raised.

MitraClip patient selection: inclusion and exclusion criteria for optimal outcomes

Edge-to-edge repair with the percutaneous MitraClip technology has changed the landscape for patients with symptomatic, severe degenerative mitral valve regurgitation who are at prohibitive surgical risk. While the results of randomized controlled trials of MitraClip therapy in patients with functional mitral valve regurgitation are still pending, single center experiences as well as registry data generally support the real-world application of the MitraClip therapy. In the majority of individuals treated with MitraClip, complete or near-complete relief of mitral regurgitation occurs, with results approaching the effectiveness of open surgery. This perspective summarizes the data, with a focus on current selection criteria of percutaneous MitraClip edge-to-edge repair that can optimize clinical outcomes.

Antiplatelet therapy in valvular and structural heart disease interventions

Transcatheter interventions for valvular and structural heart diseases are rapidly expanding due to greater operators' experience and development of new generation devices associated with increased procedural safety. They represent the standard strategy for patients with prohibitive risk for open surgery. These procedures are associated with a significant occurrence of both thrombotic and bleeding complications, thus in this setting, even more than in other percutaneous procedures, the balance between thrombotic and bleeding risk is critical. This review describes the current data available on the antithrombotic management of patients undergoing transcatheter aortic valve implantation (TAVI), percutaneous mitral valve repair with the MitraClip system, percutaneous left atrial appendage occlusion and percutaneous patent foramen ovale (PFO)/atrial septal defects (ASD) closure.

Ischemic Mitral Regurgitation: Repair, Replacement or Nothing

The treatment strategy for ischemic mitral regurgitation (MR) continues to evolve with the completion of multicenter trials and the advancement of surgical and percutaneous interventional techniques. This review defines ischemic MR, outlines key clinical trials that assess surgical and interventional approaches, and reports the main elements of recent national guidelines for decision making in treatment of ischemic MR. New findings in percutaneous mitral valve repair and replacement for ischemic MR will also be described. Effective perioperative care of patients with ischemic MR requires clinicians to be well versed in the most up-to-date recommendations and emerging technological developments.

Identification and Quantification of Degenerative and Functional Mitral Regurgitation for Patient Selection for Transcatheter Mitral Valve Repair

Chronic mitral regurgitation (MR), whether due to valve degeneration or secondary to myocardial disease, affects an increasing proportion of the aging population. Percutaneous mitral valve interventions, including edge-to-edge repair, are emerging as feasible and effective therapy for patients with severe MR at high or prohibitive surgical risk. Imaging with echocardiography is crucial for patient selection by evaluating mitral anatomy, the mechanism of dysfunction, and MR severity. In this article, the authors review the imaging characteristics for identifying and quantifying degenerative and functional MR for transcatheter mitral valve repair.

Mitral Valve Anatomic Predictors of Hemodynamic Success With Transcatheter Mitral Valve Repair

Background

Mitral regurgitation is a heterogeneous disease. Determining which patients derive optimal outcomes from transcatheter edge‐to‐edge mitral valve repair (TMVR) remains challenging. We sought to determine whether baseline mitral valve anatomic characteristics are predictive of left atrial pressure (LAP) changes during TMVR with MitraClip.

Methods and Results

Consecutive patients with severe mitral regurgitation undergoing TMVR (n=112) underwent continuous intraprocedural LAP monitoring and retrospective echocardiographic analysis for specific mitral anatomic characteristics. Procedural success (optimal LAP reduction) was defined as ≥40% reduction in left atrial V‐wave pressure compared with baseline. Echocardiographic predictors of optimal LAP reduction and increased postprocedure mean diastolic gradient were evaluated. Mean age was 79±14 years, and 36 patients (32%) were women. Primary, mixed, and secondary mitral regurgitation were present in 78 patients (70%), 22 patients (20%), and 12 patients (10%), respectively. Baseline mean LAP and V‐wave were 22±6 and 38±13 mm Hg; after TMVR, these decreased to 19±5 and 27±10 mm Hg, respectively (P<0.0001 for both). Independent predictors of optimal LAP reduction were the presence of a flail scallop, mitral regurgitation localized to a single scallop, and high‐quality 3‐dimensional echocardiographic imaging. Independent predictors of elevated postprocedure mean diastolic gradient were elevated preprocedure mean diastolic gradient, mitral annular calcification, and implantation of multiple clips.

Conclusions

Mitral valve pathoanatomic features, including a flail leaflet and single jet, are predictive of optimal LAP reduction with TMVR. High‐quality 3‐dimensional imaging may help select patients with the highest likelihood of optimal hemodynamic results with TMVR. These data expand current knowledge about patient selection for TMVR and deserve further study in larger cohorts.

Elevated Mitral Valve Pressure Gradient After MitraClip Implantation Deteriorates Long-Term Outcome in Patients With Severe Mitral Regurgitation and Severe Heart Failure

OBJECTIVES

This single-center study was performed to analyze the effect of an increased transvalvular gradient after the MitraClip (MC) (Abbott Laboratories, Abbott Park, Illinois) procedure on patient outcome during follow-up.

BACKGROUND

Percutaneous transcatheter repair of the mitral valve with the MC device has been established as a novel technique for patients with severe mitral regurgitation and high surgical risk. This study investigated the influence of an increased pressure gradient after MC implantation on the long-term outcome of patients.

METHODS

A total of 268 patients were enrolled, who received MC implantation between April 2009 and July 2014 in our institution (75 ± 9 years of age, 68% men, weight 76 ± 15 kg, median N-terminal pro-B-type natriuretic peptide 3,696 [interquartile range: 1,989 to 7,711] pg/ml, left ventricular ejection fraction 39 ± 16%, log European System for Cardiac Operative Risk Evaluation score 20% [interquartile range: 12% to 33%]). Pressure in the left atrium and left ventricle were measured during the procedure using fluid-filled catheters. The pressure gradients over the mitral valve were determined simultaneously invasively and echocardiographically directly after MC deployment. A Kaplan-Meier analysis was performed and correlated with the pressure gradients. We used a combined primary endpoint: all-cause-mortality, left ventricular assist device, mitral valve replacement, and redo procedure.

RESULTS

The Kaplan-Meier-analysis showed a significantly poorer long-term-outcome in the case of an invasively determined mitral valve pressure gradient (MVPG) in excess of 5 mm Hg at implantation for the combined endpoint (p = 0.001) and for all-cause mortality (p = 0.018). For the echocardiographically determined MVPG the cutoff value was 4.4 mm Hg. Propensity score matching was used to balance baseline differences between the groups. In a Cox model the increased residual MVPG >5 mm Hg was a significant outcome predictor in univariate and multivariate analysis (hazard ratio: 2.3; 95% confidence interval: 1.4 to 3.8; p = 0.002, multivariate after adjustment for N-terminal pro-B-type natriuretic peptide, age, and remaining mitral regurgitation).

CONCLUSIONS

It is recommended that the quality of the implantation result be analyzed carefully and repositioning of the MC be considered in the case of an elevated pressure gradient over the mitral valve.

The evolution of minimally invasive cardiac surgery: from minimal access to transcatheter approaches

The field of minimally invasive cardiac surgery has undergone rapid transformation over recent years. In this review, we provide a summary of the most current evidence supporting the use of minimally invasive aortic and mitral valve replacement techniques, as well as transcatheter approaches for aortic and mitral valve disease. As an adjunct, the use of robotically assisted coronary bypass surgery and hybrid coronary revascularization procedures is discussed. In order to obtain optimal patient outcomes, a collaborative, heart-team approach between cardiac surgeons and interventional cardiologists is necessary.