Treatment of Heart Failure With Associated Functional Mitral Regurgitation Using the ARTO System

Updated Review of Transcatheter Strategies and Intervention for Mitral Regurgitation

Mitral regurgitation (MR) is a prevalent valvular heart disease with significant morbidity, particularly in aging populations. Management strategies for MR have evolved from traditional open-heart surgery to innovative transcatheter approaches, addressing the limitations of surgical repair in high-risk patients. Transcatheter edge-to-edge repair, exemplified by devices such as MitraClip and PASCAL, has shown efficacy in reducing MR severity, improving functional capacity, and decreasing heart failure hospitalizations in selected patients. Advances in annuloplasty and chordal repair offer minimally invasive options with promising early outcomes. Transcatheter mitral valve replacement represents the frontier of MR treatment, addressing anatomical complexities unsuitable for repair, though complications such as left ventricular outflow tract obstruction persist. Emerging data from clinical trials underscore the importance of patient selection and a multidisciplinary heart team approach. In this review, each modality is discussed concerning its indications, procedural techniques, outcomes, and associated challenges. It highlights the transformative potential of transcatheter mitral valve interventions while emphasizing the need for ongoing innovation and research to optimize outcomes and expand therapeutic options for patients with severe MR.

Reverse Left Ventricular Remodeling With Transcatheter Interventions in Chronic Heart Failure Syndromes: An Updated Appraisal of the Device Landscape

Chronic heart failure (HF) is a clinical syndrome of myocardial dysfunction characterized by inadequate cardiac output or preserved output that can only be achieved by sustaining abnormal loading conditions. Morphologically, HF with reduced left ventricular function results in progressive chamber remodeling, meaning the ventricle dilates, operating at larger end-diastolic and end-systolic volumes, and takes on an abnormal, spherical shape that increases wall stress. Reverse remodeling is the goal of HF-directed therapies and can be achieved by biological means, ie, altering the loading conditions that, at a cellular level, promote myocardial dysfunction, or physical means, ie, directly altering myocardial mass or shape. In this review, we highlight the existing and emerging device-based mechanisms for biologically and physically reverse remodeling the left ventricle in chronic HF.

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.

Percutaneous reduction of septal-to-lateral mitral annular distance to increase mitral leaflet coaptation length: Preclinical study results

Objectives

Percutaneous indirect annuloplasty has emerged as a treatment strategy for functional/ischemic mitral regurgitation. This study sought to evaluate the feasibility of percutaneous indirect annuloplasty technique using a new device.

Methods

The device has 3 components: the "saddle" inserted into the great cardiac vein, the "plug" positioned in the left ventricular outflow tract, and the "bridge," a transatrial suture connecting the 2 holding elements. The aim was to shorten the septal-to-lateral distance of the mitral annulus by pulling on the saddle element. The procedure was performed through venous access in healthy adult sheep. A dedicated catheter holding a needle was used to deploy the saddle into the great cardiac vein and pierce its wall toward the left atrium to deploy the expanded polytetrafluoroethylene suture that is part of the bridge. A catheter for transseptal puncture was inserted for crossing the interatrial septum and piercing the aortic-mitral curtain, thereby allowing the plug to be deployed. The plug was held in place by the second part of the expanded polytetrafluoroethylene bridge. The 2 parts of the bridge were then joined to reduce the septal-to-lateral mitral annular distance. The septal-to-lateral distance and the coaptation length at P2 level were measured before and after the procedure using echocardiography.

Results

Overall, 10 animals were treated, 7 successfully. The mean procedure duration was 110 ± 81 minutes. Septal-to-lateral distance decreased from 3.8 mm to 2.6 mm (30%), and maximum increase of mitral leaflet coaptation was 4 mm.

Conclusions

This new approach seems promising for percutaneous treatment of functional mitral regurgitation.

Mitral Regurgitation in the High-Risk Patient: Integrating an Expanding Armamentarium of Transcatheter Devices Into the Treatment Algorithm

Over the last decade, multiple transcatheter mitral valve repair and replacement strategies have emerged, yet there is only 1 US Food and Drug Administration approved device, the MitraClip (Abbott Vascular, Inc., Santa Clara, CA). Current guidelines support the use of the MitraClip in high or prohibitive surgical risk patients, but there are many patients that are not anatomically suited for the device. This review article discusses the approach to degenerative and functional mitral regurgitation in the high-prohibitive risk patient, how to choose transcatheter treatment options (both approved and investigational), and potential management for therapy failure.

Transcatheter Coronary Sinus Interventions

The coronary sinus has become a popular route for an increasing number of innovative transcatheter interventions to treat coronary and structural heart diseases. However, interventional cardiologists have limited experience with the cardiac venous system and its highly variable anatomy. In this paper, we review the anatomy of the cardiac veins as it relates to transcatheter interventions. We also provide a contemporary overview of the emerging coronary sinus-based transcatheter therapies and their growing literature.

Numerical biomechanics modelling of indirect mitral annuloplasty treatments for functional mitral regurgitation

Mitral valve regurgitation (MR) is a common valvular heart disease where an improper closure leads to leakage from the left ventricle into the left atrium. There is a need for less-invasive treatments such as percutaneous repairs for a large inoperable patient population. The aim of this study is to compare several indirect mitral annuloplasty (IMA) percutaneous repair techniques by finite-element analyses. Two types of generic IMA devices were considered, based on coronary sinus vein shortening (IMA-CS) to reduce the annulus perimeter and based on shortening of the anterior-posterior diameter (IMA-AP). The disease, its treatments, and the heart function post-repair were modelled by modifying the living heart human model (Dassault Systèmes). A functional MR pathology that represents ischaemic MR was generated and the IMA treatments were simulated in it, followed by heart function simulations with the devices and leakage quantification from blood flow simulations. All treatments were able to reduce leakage, the IMA-AP device achieved better sealing, and there was a correlation between the IMA-CS device length and the reduction in leakage. The results of this study can help in bringing IMA-AP to market, expanding the use of IMA devices, and optimizing future designs of such devices.

Two-year outcomes from the MitrAl ValvE RepaIr Clinical (MAVERIC) trial: a novel percutaneous treatment of functional mitral regurgitation

AIMS

We report the 2-year outcomes of the MitrAl ValvE RepaIr Clinical (MAVERIC) trial. Functional mitral regurgitation (FMR) is associated with poor outcomes for which there remains an unmet clinical need. ARTO is a transcatheter annular reduction device for the treatment of FMR and an emerging alternative for patients at high surgical risk. The MAVERIC trial was designed to evaluate the safety and performance of the ARTO system in FMR and heart failure (HF).

METHODS AND RESULTS

MAVERIC is an international multicentre, prospective, single arm study enrolling patients with FMR grade ≥ 2, New York Heart Association (NYHA) class ≥II symptoms despite maximal medical therapy. Patients were excluded if they had significant structural mitral valve abnormality or life expectancy <1 year. The primary outcome measures were a composite safety outcome and efficacy defined as mitral regurgitation (MR) reduction 30 days post-procedure. Secondary outcome measures included safety, change in MR grade, NYHA class and hospitalization for HF at 2 years. Forty-five patients were enrolled. The composite safety outcome was met (2/45 adverse events at 30 days) and no device-related deaths occurred at 2-year follow-up. A sustained reduction in MR [grade < 2: 21/31 (68%) vs. 31/31(0%); P < 0.0001], left ventricular end-diastolic volume index (90.0 ± 30 vs. 106 ± 26 mL/m² ; P = 0.004) and anteroposterior diameter (35.5 ± 4.7 vs. 41.4 ± 4.6 mm; P < 0.0001) was seen at 2 years compared to baseline. Progressive symptomatic improvement [NYHA class ≤II: 27/34 (80%) vs. 12/34 (36%); P < 0.0001] and a reduction in HF hospitalizations (19.8% 2 years post vs. 52.3% 2 years prior; P < 0.001) were seen at 2 years compared to baseline.

CONCLUSIONS

The ARTO system is a safe and effective treatment for FMR with reductions in left ventricular end-diastolic volumes sustained to 2 years.

Devices for transcatheter mitral valve repair: current technology and a glimpse into the future

Introduction: Due to a large unmet need for the treatment of mitral regurgitation, transcatheter mitral valve repair devices have emerged in the last decade as an alternative therapeutic option. Given the complexity of this disease, several device systems for transcatheter mitral valve repair have been developed and are categorized according to its mechanism of action; each device has advantages and disadvantages for certain clinical and pathophysiologic characteristics, and in order to improve outcomes, proper patient selection among other key points are fundamental.Areas covered: The purpose of this article is to review the current state-of-the-art technologies available for transcatheter mitral valve repair, patient suitability, outcomes, and future perspectives.Expert opinion: Transcatheter therapy for mitral regurgitation improves outcomes and pushes the boundaries of biomedical technology while maintaining scientific rigor for device development. Surgical and percutaneous procedures should be viewed as complements to treat a wider spectrum of patients affected by this entity. Future directions from multidisciplinary innovation and cooperation will consolidate this therapeutic option.

Transcatheter mitral valve repair: an overview of current and future devices

The field of transcatheter mitral valve repair (TMVr) for mitral regurgitation (MR) is rapidly evolving. Besides the well-established transcatheter mitral edge-to-edge repair approach, there is also growing evidence for therapeutic strategies targeting the mitral annulus and mitral valve chordae. A patient-tailored approach, careful patient selection and an experienced interventional team is crucial in order to optimise procedural and clinical outcomes. With further data from ongoing clinical trials to be expected, consensus in the Heart Team is needed to address these complexities and determine the most appropriate TMVr therapy, either single or combined, for patients with severe MR.

Transcatheter mitral valve repair and replacement: the next frontier of transcatheter valve intervention

PURPOSE OF REVIEW

We summarize the recent developments in transcatheter mitral valve repair (TMVr) and replacement (TMVR), discuss determinants of MitraClip outcomes in various mitral regurgitation causes, and highlight newly emerging devices and randomized trials.

RECENT FINDINGS

The discordant results published in the two recent randomized trials for MitraClip, the COAPT and the MITRA-FR trial have led to the emergence of a new conceptual framework such as the proportionate versus disproportionate mitral regurgitation and hemodynamics assessment tools like the real-time continuous left atrial pressure monitoring. Learning curve and volume-outcome analyses and studies examining the MitraClip usage in patients with degenerative mitral regurgitation are recent developments that have influenced MitraClip regulation and coverage. Several trials for TMVr devices that take an alternative approach to the edge-to-edge repair are underway and advancements in the TMVR technologies are continuing to progress to fill the unmet needs of treating high surgical risk patients whose complex valve anatomy make TMVr unfeasible.

SUMMARY

Evidence supports careful analysis of the valve area and left ventricular function in addition to the left atrial hemodynamics will improve the MitraClip outcome. Operator experience plays a greater effect when achieving excellent results with 1+ or less residual mitral regurgitation whereas surgical MVr volume did not influence TMVr outcome. Interventions on the complex primary mitral regurgitation remain under the surgical domain, but MITRA high risk (HR) and REPAIR mitral regurgitation trials are underway to evaluate the role of MitraClip in high to intermediate surgical risk patients with primary mitral regurgitation. Despite the slow developments in TMVR, the results of the early trials of its devices are promising.

Transcatheter reshaping of the mitral annulus in patients with functional mitral regurgitation: one-year outcomes of the MAVERIC trial

AIMS

The aim of this study was to assess the one-year safety and efficacy of the transcatheter ARTO system in the treatment of functional mitral regurgitation (FMR).

METHODS AND RESULTS

MAVERIC is a multicentre, prospective, non-randomised pre-commercial study. Eligible patients were on guideline-recommended therapy for NYHA Class II-IV systolic heart failure and had an FMR grade ≥2+. The ARTO system was implanted in forty-five (100%) patients. The primary safety composite endpoint (death, stroke, myocardial infarction, device-related surgery, cardiac tamponade, renal failure) at 30 days and one year was 4.4% (95% CI: 1.5-16.6) and 17.8% (95% CI: 9.3-32.4), respectively. Periprocedural complications occurred in seven patients (15.5% [95% CI: 6.5-29.5]), and five patients (11.1% [95% CI: 4.9-24.0]) died during one-year follow-up. Paired results for 36 patients demonstrated that 24 (66.7%) had grade 3+/4+ mitral regurgitation at baseline; however, only five (13.9%) and three (8.3%) patients remained at grade 3+/4+ 30 days and one year post procedure (p<0.0001). Echocardiographic parameters such as anteroposterior annulus diameter decreased from 41.4 mm (baseline) to 36.0 and 35.3 mm at 30 days and one year, respectively (p<0.0001). Twenty-five patients (69.4%) had baseline NYHA Class III/IV symptoms decreasing significantly to nine (25.0%) at 30 days and eight (22.2%) at one year post procedure (p<0.0001).

CONCLUSIONS

The ARTO transcatheter mitral valve repair system is both safe and effective in decreasing FMR up to one year post procedure.

Cardiac resynchronization therapy pacemaker implant in a patient with ARTO mitral device in situ

The ARTO device is a percutaneous device for functional mitral regurgitation composed of a transseptal anchor and a T-bar sitting in the coronary sinus which reduce the minor axis of the mitral valve. We present a case showing the technical feasibility of an LV lead implant in patients with an ARTO device in situ.

Over 15 years: the advancement of transcatheter mitral valve repair

Patients with severe symptomatic mitral regurgitation, if left untreated, have a poor prognosis. In those patients not eligible for mitral valve (MV) surgery, percutaneous repair may improve clinical outcomes. In the past 15 years several devices have been developed to address different MV lesions. This manuscript will review the advancement of transcatheter MV repair through the years, focusing on technologies for which consistent clinical data is available.

Transcatheter mitral valve repair: review of current techniques

Mitral regurgitation is common and is associated with excess morbidity and mortality. Despite these poor outcomes, only a minority of affected patients undergo mitral surgery, for several reasons, which underlines the substantial unmet need for treatment for this disorder. Transcatheter mitral valve repair interventions have been developed to treat mitral regurgitation in an undertreated patient population. The aim of this status quo review is to provide an overview of currently available transcatheter mitral valve repair techniques, the different approaches and the clinical outcomes reported so far.

Transcatheter Mitral Valve Repair and Replacement: What's on the Horizon?

There are more than 4 million people affected by mitral regurgitation in both the United States and Europe. Prior to the last decade the only options for treatment of MR were medical therapy and open-heart surgery which left many high risk patients with little option once medically optimized. However, we saw a flood in innovative transcatheter mitral valve interventions. As the technologies are refined these new approaches are considerably less invasive and for some high-risk patients may represent a superior option to conventional open-heart surgery. There are 3 main approaches currently being considered for transcatheter mitral valve repair, edge to edge repair, indirect annuloplasty and direct annuloplasty. There have also been large advancements in recent years in transcatheter replacement of the mitral valve. Although many of these devices are under investigation still, we sought to examine the current state of innovative transcatheter mitral valve technologies.

Percutaneous mitral repair: current and future devices

Mitral regurgitation (MR) is the second most common valvular heart disease and its prevalence is increasing with population ageing. In the recent years we have witnessed the development of several transcatheter devices to correct MR in patients at high-risk for surgery. The majority of evidence regarding safety and efficacy of this new therapy comes from MitraClip studies. However, new alternatives on the field of valve repair have emerged with promising results. The aim of this review is to portrait the landscape of transcatheter mitral repair alternatives, from currently used devices to those that will have a role in the near future.

The first two cases of transcatheter mitral valve repair with ARTO system in Asia

BACKGROUND

MAVERIC (Mitral Valve Repair Clinical Trial) validates the safety and efficacy of the ARTO system. We here report the first two successful cases of utilizing the ARTO system in patients with symptomatic heart failure (HF) with functional mitral regurgitation (FMR) in Asia.

METHODS

Two patients, aged 70 and 63, had severe HF with FMR. Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50% with severe mitral regurgitation (MR) in both patients. Optimizing drug treatment could not mitigate their symptoms. Therefore, we used the ARTO system to repair the mitral valve for these patients on March 5 and 6, 2019, respectively.

RESULTS

Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients. MR was decreased immediately after the procedures in both patients. The 30-day and 3-month transthoracic echocardiography (TTE) revealed a moderate to severe MR in both patients, and the New York Heart Association (NYHA) scales were also partially improved.

CONCLUSION

The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR, and the patient selection appears to be crucial.

Recent Developments in Catheter-Based Cardiac Procedures

New developments in transcatheter valve technologies including aortic valve replacement and mitral valve and tricuspid valve interventions are described. Recent studies evaluating the success rate, patient outcomes, and anesthesiologic management of the procedures are discussed.

Transcatheter mitral repair and replacement: which procedure for which patient?

Given the complexity and the heterogeneity of mitral valve anatomy and pathology, different technologies and approaches (including repair and replacement methods) are potentially required to allow specific patient-tailored approaches, addressing each anatomy with the most appropriate device. Since we are still far from having an unbiased and evidence-supported process to select the best treatment for each patient, this review will provide an overview of the elements that should be taken into consideration when selecting the best procedure for each patient.

Emerging Technologies for Percutaneous Mitral Valve Repair

Mitral regurgitation (MR) is a common disease affecting more than 4 million people in the United States and the European Union. A significant number of percutaneous valves have been developed recently, specifically designed for the mitral anatomy, and with a promising evidence of good procedural and echocardiographic outcomes. However, even if transcatheter mitral valve replacement (TMVR) will have a role in the future of percutaneous treatment of both functional and degenerative mitral regurgitation, percutaneous mitral valve repair will always play a vital role in the treatment of MR because of the favorable safety profile and the fact that it respects the native anatomy. In this review, we will discuss the new emerging technologies under development to treat mitral regurgitation focusing on different devices that aim to target different components of the mitral anatomy.

Transcatheter mitral valve repair: review of the clinical evidence

Over the past decade, different transcatheter repair techniques have been developed to treat mitral regurgitation (MR) with less invasive approaches in order to address the unmet clinical need of untreated patients with MR. The aim of this report is to provide an overview of the currently available transcatheter mitral repair options, focusing on the evidence reported so far.

Percutaneous Mitral Valve Interventions (Repair): Current Indications and Future Perspectives

Mitral valve regurgitation (MR) is the commonest valvular abnormality encountered among adult patients with cardiac valvular disease and conveys significant morbidity and mortality. The mitral valve is a complex anatomical structure and etiology for regurgitation is classified as either primary or secondary MR. Identification of the etiology in severe MR is critical in determining the appropriate treatment strategy. Transcatheter mitral valve repair (TMVR) is a minimally invasive technique for treatment of selected patients with symptomatic chronic moderate-severe or severe (3 to 4+) MR. While surgery remains the mainstay for treatment in primary MR, several technological advances within the last decade have made transcatheter mitral valve intervention increasingly feasible and safe in clinical practice. Use of TMVR in patients with severe MR has successfully reduced patient symptoms, disease morbidity, improved quality of life, and facilitated reverse remodeling with potential for a survival advantage among certain patients with secondary MR. Recent randomized controlled trials on MitraClip use in secondary MR have reinvigorated interest in this disease and refocused our attention on optimizing patient selection and timing of intervention to maximize benefit from using such percutaneous devices. In our review, we discuss etiologies and pathophysiology in both acute MR and development of chronic severe MR. We discuss management strategies for MR among patients based on etiology, particularly percutaneous mitral valve interventional therapies. We perform an extensive review comparing and contrasting existing data on safety, efficacy, durability, and appropriate patient selection related to MitraClip implantation in both primary and secondary MR. Lastly, we explore percutaneous MV therapies beyond the MitraClip as we await larger scale trials on these devices prior to them making way into day-to-day practice.

Indirect Annuloplasty to Treat Functional Mitral Regurgitation: Current Results and Future Perspectives

The incidence of mitral regurgitation (MR) is approximately 1.7% in the developed world, and this increases to more than 10% in patients aged over 75 years. Functional (or secondary) mitral regurgitation (FMR) is defined as poor leaflet coaptation and tethering secondary to either ischemic or non-ischemic left ventricular (LV) dysfunction and dilatation. FMR is more common than degenerative (or primary) MR and is associated with significantly worse outcomes in patients with heart failure, post myocardial infarction and following coronary artery bypass graft surgery. Patients with severe degenerative MR have excellent outcomes with surgical repair, however the benefits of surgery in FMR are less clear. Although annuloplasty is associated with a lower operative mortality compared to replacement, the recurrence rate of mitral regurgitation is high in patients with FMR and neither surgical repair or replacement have been shown to reduce hospitalisation or death in FMR. Furthermore, nearly half of patients are deemed too high risk for surgery and therefore most patients are managed conservatively and there remains an unmet clinical need. Transcatheter mitral valve interventions are an emerging alternative for those at high surgical risk. This mini review focuses on indirect mitral annuloplasty: anatomical considerations, patient selection, current devices, implantation techniques and the associated clinical outcome data.

Functional Mitral Regurgitation: An Interventional Cardiologist's Perspective

Functional mitral regurgitation (FMR) is common in patients with heart failure and portends a poor prognosis. The etiology is secondary to nonischemic or ischemic (postmyocardial infarction) adverse remodeling. Treatment includes guideline-directed medical therapy, cardiac resynchronization therapy, and in some cases, surgical repair or replacement. Transcatheter mitral valve (MV) repair with the MitraClip device is approved in patients with degenerative MR and is currently under investigation for use in FMR, as are several transcatheter MV replacement devices. This review discusses the basis of FMR pathophysiology, classification, and prognosis; provides an overview of current therapeutic approaches; examines the available literature on the use of MitraClip in patients with FMR; and provides insight into ongoing clinical trials and new investigational devices for the treatment of FMR.

Future Technology

Mitral regurgitation is the most common valvular disease and significant (moderate/severe) mitral regurgitation is found in 2.3% of the population older than 65 years. New transcatheter minimally invasive technologies are being developed to address mitral valve disease in patients deemed too high a risk for conventional open-heart surgery. There are several features of the mitral valve (saddle-shaped noncalcified annulus with irregular leaflet geometry) that make a transcatheter approach to repair or replacing the valve more challenging compared with the aortic valve. Several devices are under investigation for transcatheter mitral valve replacement, and also for mitral valve repair targeting the mitral valve leaflets, chordae tendinae, and mitral annulus. The MitraClip device is the only Food and Drug Administration-approved device to treat mitral regurgitation by targeting the mitral leaflets. There are eight minimally invasive devices being studied in humans that target the mitral annulus, and at least two devices being studied in animal models. There are 5 devices in clinical trials for minimally invasive approaches targeting the chordae tendinae. More than 10 different transcatheter mitral valves are in various stages of development and clinical trials. These transcatheter mitral valves can be delivered either through a transseptal, transapical, transaortic, or left atriotomy approach. It seems likely that transcatheter treatment approaches to mitral valve disease will become more common, at least in the sick and elderly patient population.

Therapeutic options for functional mitral regurgitation in chronic heart failure

INTRODUCTION

Mitral regurgitation is a common finding in patients with chronic heart failure and is associated with a progressive worsening of symptoms, reduced survival and increased cost of care. However, the use of mitral valve surgery for these patients remains controversial and has not been shown to improve survival. Consequently, research has been increasingly directed towards the nonsurgical management of this important co-morbidity of heart failure.

AREAS COVERED

The present review will describe the relevance of mitral regurgitation in people with chronic heart failure, the current options for percutaneous treatment and the evidence base for each of these.

EXPERT COMMENTARY

Although at present there are few solid data to guide heart teams in deciding what degree of mitral regurgitation to treat, in which patients, and with what, this situation is likely to change over the next two years with the release of the first large randomised trials of percutaneous interventions.

Transcatheter valve interventions in heart failure: new answers to old questions

Heart failure (HF) is often associated with different valve diseases, predominantly functional mitral and tricuspid regurgitation. However, the association between HF and aortic stenosis, particularly low-flow low-gradient aortic stenosis, is not infrequent. Severe mitral and tricuspid regurgitations, as well as aortic stenosis, in HF patients worsen prognosis and left ventricular dilatation and induce further reduction in left ventricular ejection fraction. Transcatheter edge-to-edge mitral and tricuspid valve repair and transcatheter aortic valve implantation could be an important therapeutic option with a satisfactory long-term outcome in HF patients with comorbidities and even in patients with severely depressed ejection fraction.

New percutaneous interventions in heart failure

Chronic heart failure (HF) is one of the main causes of mortality and morbidity worldwide and represents a growing challenge in interventional cardiology. Its prevalence is recently increasing due to the improvements in cardiac care with subsequent significant reduction in the HF acute mortality. HF may occur with either a reduced left ventricular ejection fraction (LVEF) (LVEF<40%, HFrEF) or a preserved EF (typically LVEF≥50%, HFpEF) indicative of diastolic dysfunction. Despite recent advances in drug therapies as well as in nonpharmacological strategies, including defibrillators, cardiac resynchronization therapy, LV assist devices, mortality in HF remains high. New transcatheter implantable devices have been developed to improve the treatment of chronic HF. In this review we will summarize data on interventional HF devices that are currently approved or under investigation including treatment alternatives for mitral and tricuspid regurgitation, LV restoration through partitioning devices and left atrial decompression with shunting devices.

Mitral Loop Cerclage Annuloplasty for Secondary Mitral Regurgitation: First Human Results

OBJECTIVES

This is an early feasibility clinical test of mitral loop cerclage annuloplasty to treat secondary mitral valve regurgitation.

BACKGROUND

Secondary mitral regurgitation is characterized by cardiomyopathy, mitral annular enlargement, and leaflet traction contributing to malcoaptation. Transcatheter mitral loop cerclage applies circumferential compression to the mitral annulus by creating a loop through the coronary sinus across the interventricular septum, protecting entrapped coronary arteries from compression, and interactive annular reduction under echocardiographic guidance. This is the first human test of mitral loop annuloplasty.

METHODS

Five subjects with severe symptomatic secondary mitral regurgitation underwent mitral loop cerclage, with echocardiographic and computed tomography follow-up over 6 months.

RESULTS

Mitral loop cerclage was successful in 4 of 5 subjects and aborted in 1 of the 5 because of unsuitable septal coronary vein anatomy. Immediately and over 6 months, measures of both mitral valve regurgitation (effective orifice area and regurgitation fraction) and chamber dimensions (left atrial and left ventricular volumes) were reduced progressively and ejection fractions increased. Two with persistent and permanent atrial fibrillation spontaneously reverted to sinus rhythm during follow-up. One subject experienced a small myocardial infarction from an unrecognized small branch coronary occlusion. Another, experiencing cardiogenic shock at baseline, died of intractable heart failure after 6 weeks.

CONCLUSIONS

In this first human test, mitral loop cerclage annuloplasty was successful in 4 of 5 attempts, caused reverse remodeling (reduction in secondary mitral regurgitation and heart chamber volumes), and suggested electrical remodeling (reversion of atrial fibrillation). Further evaluation is warranted.

Interventional Therapies for Heart Failure in Older Adults

Heart failure (HF) remains the leading cause of hospitalization in older adults and is associated with increased morbidity and mortality despite the use of guideline-directed medical therapy. There has been tremendous progress in the development of novel transcatheter and interventional therapies for HF over the past decade. The evolution of structural heart disease interventions and interventional HF has led to a multidisciplinary heart team approach in the management of HF patients. Careful selection of the appropriate patient population and end points in future randomized controlled trials will be crucial to demonstrate the potential efficacy of the novel interventional HF therapies.

Transcatheter Therapy for Mitral Regurgitation Clinical Challenges and Potential Solutions

Severe mitral regurgitation is a common and complex disease that is associated with an adverse prognosis. For decades, surgical treatment has been the standard of care. Recently, multiple technologies for transcatheter mitral therapy have emerged, with the potential for both repair and replacement in patients with native mitral regurgitation. Transcatheter mitral technologies have potential as solutions for unmet clinical needs. Further rigorous clinical studies are needed to determine their efficacy and safety, as well as the appropriate patient candidates. These evaluations will help to define the role of transcatheter mitral therapy as a potentially exciting new strategy to improve the lives of patients with mitral regurgitation.

Pulmonary hypertension due to left heart disease

Pulmonary hypertension due to left heart disease, also known as group 2 pulmonary hypertension according to the European Society of Cardiology/European Respiratory Society classification, is the most common cause of pulmonary hypertension. In patients with left heart disease, the development of pulmonary hypertension favours right heart dysfunction, which has a major impact on disease severity and outcome. Over the past few years, this condition has been considered more frequently. However, epidemiological studies of group 2 pulmonary hypertension are less exhaustive than studies of other causes of pulmonary hypertension. In group 2 patients, pulmonary hypertension may be caused by an isolated increase in left-sided filling pressures or by a combination of this condition with increased pulmonary vascular resistance, with an abnormally high pressure gradient between arteries and pulmonary veins. A better understanding of the conditions underlying pulmonary hypertension is of key importance to establish a comprehensive diagnosis, leading to an adapted treatment to reduce heart failure morbidity and mortality. In this review, epidemiology, mechanisms and diagnostic approaches are reviewed; then, treatment options and future approaches are considered.

Interventional approaches to mitral regurgitation. What's in the pipeline?

Mitral regurgitation (MR) is the most prevalent valvular heart disease in the Western world. Surgical repair is the gold standard for the treatment of degenerative MR in low-risk patients. Given the rising number of patients with functional MR and higher operative risk due to relevant comorbidities and increasing age, interventional approaches to repair or replace diseased mitral valves are on the rise. However, the complex anatomy and physiology of the mitral valve and its adjacent valve apparatus bear major challenges. To date, only the MitraClip device has been used in a large number of patients; however, several other devices and systems specifically targeted at different underlying pathologies of MR are currently under development. In addition to valve repair, the first steps toward mitral valve replacement have been taken. The present article reviews the current state of the art of interventional approaches to mitral valve disease and its future perspectives.