Correction of Mitral Regurgitation in Nonresponders to Cardiac Resynchronization Therapy by MitraClip Improves Symptoms and Promotes Reverse Remodeling

Outcomes of mitral TEER in non-responders to cardiac resynchronization therapy: A systematic review and meta-analysis

BACKGROUND

Secondary mitral regurgitation (MR) worsens in 10-15 % of heart failure (HF) patients receiving cardiac resynchronization therapy (CRT). Transcatheter edge-to-edge repair (TEER) with Mitra-Clip (Abbot Vascular, Santa Clara, CA, USA) therapy is associated with improved survival and decreased rates of hospitalization for HF in selected patients with secondary MR. Data on TEER outcomes in CRT-non-responders are limited. The purpose of this meta-analysis was to evaluate outcomes of mitral TEER with Mitra-Clip in CRT-non-responders.

METHODS

Cochrane, Scopus, MEDLINE, and EMBASE were searched for studies discussing outcomes of Mitra-Clip in CRT non-responders. Two reviewers were independently involved in screening studies and extracting relevant data. Individual study incidence rate estimates underwent logit transformation to calculate the weighted summary proportion under the random effect model.

RESULTS

A total of eight reports met the inclusion criteria (439 patients). Mitra-Clip improved MR grade to ≤2+ in 83.8 % and 86.8 % of CRT non-responders at six months and one year, respectively. Symptomatic improvement (New York Heart Association class ≤II) was also found in 71 % and 78.1 % of CRT non-responders at six months and one year, respectively. The pooled overall incidence estimates of mortality at 30 days, 6 months, 1 year, and 2 years were 3.6 %, 9.2 %, 17.8 %, and 25.9 %, respectively.

CONCLUSION

TEER with Mitra-Clip in patients with significant secondary MR who do not respond to CRT was associated with MR improvement, alleviation of symptoms, and mortality rates similar to those in the COAPT trial.

Impact of transcatheter edge to edge repair in functional mitral regurgitation and cardiac resynchronization-therapy nonresponders

BACKGROUND

Despite optimal medical therapy and cardiac resynchronization therapy (CRT), significant functional mitral regurgitation (MR) persisted in 30% of the patients and labeled as CRT nonresponders.

AIMS

We sought to study the impact of transcatheter edge-to-edge repair (TEER) in patients with symptomatic grade III and IV functional MR despite CRT.

METHODS

A retrospective analysis was conducted of all patients who had prior CRT for at least 6 months and underwent TEER for significant residual functional MR (grade ≥3) and symptomatic heart failure (HF) at our institution. The primary outcomes were the change in New York Heart Association classification (NYHA), MR grade, echo parameters, and NT-ProBNP from baseline to 1-year post-procedure.

RESULTS

A total of 28 patients were identified, mean age of 73 ± 6.7 years and 89% males. Procedure success was achieved in all patients. At 1-year follow-up, patients had lower MR grade (median 2, IQR 1 [1,2] vs. 4, IQR 1 [3,4]; p < 0.001), NYHA class (median 2, IQR 1 [2,3] vs. 3, IQR 1 [3,4]; p < 0.001), and NT-ProBNP (7658 ± 11322 vs. 3760 ± 4431; p = 0.035) compared to before the TEER procedure. The left ventricular end-diastolic volume (255 ± 59 vs. 244 ± 66 mm; p = 0.016) and the right ventricular systolic pressure (52 ± 14 mmHg vs. 37 ± 13 mmHg, <0.001) decreased.

CONCLUSION

Patients who remain symptomatic after CRT with severe functional MR had improved functional status and MR grade at 1-year following TEER. There was a signal toward reverse remodeling.

Significant Mitral Regurgitation After Permanent Right Ventricular Pacemaker Implantation: Prognostic Implications

The underlying mechanisms leading to the development of mitral regurgitation (MR) after right ventricular (RV) pacemaker (PM) implantation and its prognostic value have yet to be fully understood. The purpose of this study was to evaluate the prevalence and clinical variables associated with the development of MR after RV pacing and its association with outcomes. A total of 451 patients (mean age 69 ± 15 years, 61% male) who underwent de novo RV PM implantation were included. The development of significant MR, defined as ≥moderate from mild or none/trace at baseline, occurred in 131 (29%) patients at a median of 2.4 years (interquartile range: 1.0 to 3.8 years) after PM implantation. Multivariate logistic regression analysis demonstrated that implantation of a single-chamber PM, left ventricular end-systolic volume index, and the presence of mild MR (vs no MR) at baseline were independently associated with the development of significant MR post-implant. Cardiac events, defined as the composite of all-cause mortality or heart failure hospitalization, occurred in 143 patients (31.7%) during a median follow-up of 5.4 years (interquartile range: 3.0 to 8.1 years). Multivariate Cox regression analysis demonstrated that the development of significant MR was independently related to the occurrence of cardiac events. In conclusion, the development of significant MR after PM implantation is seen in about one-third of recipients and is independently associated with adverse cardiac events.

Randomized investigation of the MitraClip device in heart failure: Design and rationale of the RESHAPE-HF2 trial design

AIMS

The safety and effectiveness of the MitraClip device to treat functional mitral regurgitation (FMR) has been tested in previous clinical trials yielding somewhat heterogeneous results in heart failure (HF) patients. Over time, the MitraClip device system has been modified and clinical practice evolved to consider also less severely diseased HF patients with FMR for this therapeutic option. The RESHAPE-HF2 trial aims to assess the safety and effectiveness of the MitraClip device system on top of medical therapy considered optimal in the treatment of clinically significant FMR in symptomatic patients with chronic HF.

METHODS

The RESHAPE-HF2 is an investigator-initiated, prospective, randomized, parallel-controlled, multicentre trial designed to evaluate the use of the MitraClip device (used in the most up-to-date version as available at sites) plus optimal standard of care therapy (device group) compared to optimal standard of care therapy alone (control group). Eligible subjects have signs and symptoms of HF (New York Heart Association [NYHA] class II-IV despite optimal therapy), and have moderate-to-severe or severe FMR, as confirmed by a central echocardiography core laboratory; have an ejection fraction between ≥20% and ≤50% (initially 15-35% for NYHA class II patients, and 15-45% for NYHA class III/IV patients); have been adequately treated per applicable standards, and have received appropriate revascularization and cardiac resynchronization therapy, if eligible; had a HF hospitalization or elevated natriuretic peptides (B-type natriuretic peptide [BNP] ≥300 pg/ml or N-terminal proBNP ≥1000 pg/ml) in the last 90 days; and in whom isolated mitral valve surgery is not a recommended treatment option. The trial has three primary endpoints, which are these: (i) the composite rate of total (first and recurrent) HF hospitalizations and cardiovascular death during 24 months of follow-up, (ii) the rate of total (i.e. first and recurrent) HF hospitalizations within 24 months, and (iii) the change from baseline to 12 months in the Kansas City Cardiomyopathy Questionnaire overall score. The three primary endpoints will be analysed using the Hochberg procedure to control the familywise type I error rate across the three hypotheses.

CONCLUSIONS

The RESHAPE-HF2 trial will provide sound evidence on the MitraClip device and its effects in HF patients with FMR. The recruitment was recently completed with 506 randomized patients.

Functional Mitral Regurgitation: Patient Selection and Optimization

Functional mitral regurgitation appears commonly among all heart failure phenotypes and can affect symptom burden and degree of maladaptive remodeling. Transcatheter mitral valve edge-to-edge repair therapies recently became an important part of the routine heart failure armamentarium for carefully selected and medically optimized candidates. Patient selection is considering heart failure staging, relevant comorbidities, as well as anatomic criteria. Indications and device platforms are currently expanding.

New Perspective on Pathophysiology and Management of Functional Mitral Regurgitation

Functional mitral regurgitation (FMR) occurs as a result of global or segmental left ventricular (LV) dysfunction or left atrial dilatation, leading to mitral annular dilatation, papillary muscle displacement, mitral valve (MV) leaflet tethering, and leaflet remodeling. The prevalence of FMR continues to rise in the United States. Even mild FMR is associated with adverse clinical outcomes. Echocardiography is the primary imaging modality used to assess the type and severity of mitral regurgitation. FMR treatment depends on the etiology. Evidence-based pharmacologic and cardiac resynchronization therapies for underlying LV dysfunction remain the mainstay of treatment. Patients who remain symptomatic despite optimal medical therapy can be considered for surgical or percutaneous MV intervention. This article reviews the pathophysiology, imaging evaluation, and therapeutic options of FMR, highlighting the most recent developments in a rapidly evolving field.

MitraClip® procedure as bridge to left ventricular assist device: Enable extracorporeal membrane oxygenation weaning and reduce perioperative risk

Secondary mitral valve regurgitation is a frequent consequence of left ventricular dysfunction in patients with severe heart failure. The management of this disease can be challenging since it often culminates in refractory pulmonary edema and multi-organ failure. We present the case of a 50-year-old male who was admitted in cardiogenic shock following myocardial infarction. After successful revascularization, percutaneous mitral valve repair using the MitraClip^® device enabled weaning from extracorporeal membrane oxygenation followed by the implantation of a left ventricular assist device as bridge to transplant.

Edge-to-edge percutaneous mitral repair for functional ischaemic and non-ischaemic mitral regurgitation: a systematic review and meta-analysis

AIM

Randomized controlled trials comparing the use of the MitraClip device in addition to guideline directed medical therapy (GDMT) to GDMT alone in patients with secondary mitral regurgitation (MR) have shown conflicting results. However, if these differences could be due to the underlying MR aetiology is still unknown. Therefore, we aimed to evaluate if the effects of percutaneous edge-to-edge repair with MitraClip implantation could differ in patients with ischaemic (I-MR) and non-ischaemic mitral regurgitation (NI-MR).

METHODS AND RESULTS

PubMed, Embase, BioMed Central, and the Cochrane Central Register of Controlled Trials were searched for all studies including patients with secondary MR treated with the MitraClip device. Data were pooled using a random-effects model. Primary endpoint was the composite of all-cause death and heart failure-related hospitalization. Secondary endpoints were the single components of the primary endpoint, New York Heart Association functional Classes III and IV, and mitral valve re-intervention. Seven studies enrolling 2501 patients were included. Patients with I-MR compared with patients with NI-MR had a similar risk of the primary endpoint (odds ratio: 1.17; 95% confidence interval: 0.93 to 1.46; I2 : 0%). The risk of all-cause death was increased in patients with I-MR (odds ratio: 1.31; 95% confidence interval: 1.07 to 1.62; I2 : 0%), while no differences were observed between the two groups in terms of the other secondary endpoints.

CONCLUSIONS

The risk of mortality after MitraClip implantation is lower in patients with NI-MR than in those with I-MR. No absolute differences in the risk of heart failure related hospitalization were observed between groups.

Percutaneous Edge-to-Edge Mitral Valve Repair for Functional Mitral Regurgitation

The presence and severity of functional mitral regurgitation (FMR) is associated with worse outcomes in patients with heart failure and reduced ejection fraction. Prior to the availability of percutaneous mitral valve repair, management for FMR has been limited to medical therapy, cardiac resynchronization therapy for a specific subset of patients and surgery which has yet to demonstrate mortality benefits. Transcatheter edge-to-edge repair (TEER) of the mitral valve has emerged in the past decade as an invaluable member of the armamentarium against FMR with the 2 landmark randomized controlled trials providing deep insights on patient selection. In addition, TEER has spurred the rapid advancement in our understanding of FMR. This article seeks to provide an overview as well as our current understanding on the role of TEER in FMR.

Impact of physiological pacing on functional mitral regurgitation in systolic dysfunction: Initial echocardiographic remodeling findings after His bundle pacing

BACKGROUND

Although His bundle pacing (HBP) has been shown to improve left ventricular ejection fraction (LVEF), its impact on mitral regurgitation (MR) remains uncertain.

OBJECTIVES

The aim of this study was to evaluate change in functional MR after HBP in patients with left ventricular (LV) systolic dysfunction.

METHODS

Paired echocardiograms were retrospectively assessed in patients with reduced LVEF (<50%) undergoing HBP for pacing or resynchronization. The primary outcomes assessed were change in MR, LVEF, LV volumes, and valve geometry pre- and post-HBP. MR reduction was characterized as a decline in ≥1 MR grade post-HBP in patients with ≥grade 3 MR at baseline.

RESULTS

Thirty patients were analyzed: age 68 ± 15 years, 73% male, LVEF 32% ± 10%, 38% coronary artery disease, 33% history of atrial fibrillation. Baseline QRS was 162 ± 31 ms: 33% left bundle branch block, 37% right bundle branch block, 17% paced, and 13% narrow QRS. Significant reductions in LV end-systolic volume (122 mL [73-152 mL] to 89 mL [71-122 mL], P = .006) and increase in LV ejection fraction (31% [25%-37%] to 39% [30%-49%], P < .001) were observed after HBP. Ten patients had grade 3 or 4 MR at baseline, with reduction in MR observed in 7. In patients with at least grade 3 MR at baseline, reduction in LV volumes, improved mitral valve geometry, and greater LV contractility were associated with MR reduction. Greater reduction in paced QRS width was present in MR responders compared to non-MR responders (-40% vs -25%, P = .04).

CONCLUSIONS

In this initial detailed echocardiographic analysis in patients with LV systolic dysfunction, HBP reduced functional MR through favorable ventricular remodeling.

Optimized implementation of cardiac resynchronization therapy: a call for action for referral and optimization of care

Cardiac resynchronization therapy (CRT) is one of the most effective therapies for heart failure with reduced ejection fraction and leads to improved quality of life, reductions in heart failure hospitalization rates and all-cause mortality. Nevertheless, up to two-thirds of eligible patients are not referred for CRT. Furthermore, post-implantation follow-up is often fragmented and suboptimal, hampering the potential maximal treatment effect. This joint position statement from three European Society of Cardiology Associations, Heart Failure Association (HFA), European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI), focuses on optimized implementation of CRT. We offer theoretical and practical strategies to achieve more comprehensive CRT referral and post-procedural care by focusing on four actionable domains: (i) overcoming CRT under-utilization, (ii) better understanding of pre-implant characteristics, (iii) abandoning the term 'non-response' and replacing this by the concept of disease modification, and (iv) implementing a dedicated post-implant CRT care pathway.

Optimized implementation of cardiac resynchronization therapy: a call for action for referral and optimization of care: A joint position statement from the Heart Failure Association (HFA), European Heart Rhythm Association (EHRA), and European Association of Cardiovascular Imaging (EACVI) of the European Society of Cardiology

Cardiac resynchronization therapy (CRT) is one of the most effective therapies for heart failure with reduced ejection fraction and leads to improved quality of life, reductions in heart failure hospitalization rates and all-cause mortality. Nevertheless, up to two-thirds of eligible patients are not referred for CRT. Furthermore, post-implantation follow-up is often fragmented and suboptimal, hampering the potential maximal treatment effect. This joint position statement from three European Society of Cardiology Associations, Heart Failure Association (HFA), European Heart Rhythm Association (EHRA) and European Association of Cardiovascular Imaging (EACVI), focuses on optimized implementation of CRT. We offer theoretical and practical strategies to achieve more comprehensive CRT referral and post-procedural care by focusing on four actionable domains: (i) overcoming CRT under-utilization, (ii) better understanding of pre-implant characteristics, (iii) abandoning the term 'non-response' and replacing this by the concept of disease modification, and (iv) implementing a dedicated post-implant CRT care pathway.

The role of transcatheter mitral valve leaflet approximation for the treatment of secondary mitral regurgitation: current status and future prospects

Introduction: Secondary mitral regurgitation (SMR) is one of the most common valvulopathies and is associated with poor prognosis. Over the past years, medical management and mitral valve repair options have rapidly evolved offering new opportunities for a wide range of patients.Areas covered: We provide an up-to-date review of the value of medical and transcatheter mitral valve leaflet approximation for SMR integrating the results of most recent trials and putting their findings into clinical perspective.Expert opinion: Treatment of SMR requires a multidisciplinary approach with a long-term perspective. After optimization of medical treatment, transcatheter mitral valve repair should be considered in patients with persisting symptomatic severe SMR to improve symptoms and prognosis.

Percutaneous Mitral Valve Intervention Using MitraClip for Functional Mitral Regurgitation and Heart Failure

Functional mitral regurgitation (FMR) frequently coexists with left ventricular systolic dysfunction and advanced heart failure, and typically has poor clinical outcomes. Although various therapeutic options including cardiac resynchronization therapy and surgical mitral intervention, have been proposed, an optimal treatment strategy for functional mitral regurgitation has not yet been established. Over the last decade, transcatheter mitral valve repair using MitraClip has emerged as a novel alternative therapeutic option for functional mitral regurgitation. In 2018, the COAPT trial demonstrated that MitraClip treatment reduced rehospitalization due to heart failure and all-cause death in patients with functional mitral regurgitation and heart failure. As a consequence, the MitraClip has become a very promising potential treatment for functional mitral regurgitation. In this review, we discuss and summarize the current status and future perspectives of the treatment for functional mitral regurgitation and heart failure.

Selection of the Optimal Candidate to MitraClip for Secondary Mitral Regurgitation: Beyond Mitral Valve Morphology

Secondary mitral regurgitation (MR) occurs despite structurally normal valve apparatus due to an underlying disease of the myocardium leading to disruption of the balance between tethering and closing forces with ensuing failure of leaflet coaptation. In patients with heart failure (HF) and left ventricular dysfunction, secondary MR is independently associated with poor outcome, yet prognostic benefits related to the correction of MR have remained elusive. Surgery is not recommended for the correction of secondary MR outside coronary artery bypass grafting. Percutaneous mitral valve repair (PMVR) with MitraClip implantation has recently evolved as a new transcatheter treatment option of inoperable or high-risk patients with severe MR, with promising results supporting the extension of guideline recommendations. MitraClip is highly effective in reducing secondary MR in HF patients. However, the derived clinical benefit is still controversial as two randomized trials directly comparing PMVR vs. optimal medical therapy in severe secondary MR yielded virtually opposite conclusions. We reviewed current evidence to identify predictors of PMVR-related outcomes in secondary MR useful to improve the timing and the selection of patients who would derive maximal benefit from MitraClip intervention. Beyond mitral valve anatomy, optimal candidate selection should rely on a comprehensive diagnostic workup and a fine-tuned risk stratification process aimed at (i) recognizing the substantial heterogeneity of secondary MR and its complex interaction with the myocardium, (ii) foreseeing hemodynamic consequences of PMVR, (iii) anticipating futility and (iv) improving symptoms, quality of life and overall survival.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Impact of transcatheter mitral valve repair on ventricular arrhythmias

AIMS

Patients with heart failure and severe mitral regurgitation (MR) have a poor prognosis and carry an increased risk for ventricular arrhythmias. The present study evaluates the impact of transcatheter mitral valve repair using the MitraClip on the potential reduction of ventricular arrhythmias.

METHODS AND RESULTS

Patients undergoing MitraClip implantation were prospectively enrolled into the present study and received 24 h Holter ECG assessment prior to and 6 months after the procedure. In addition, left ventricular dimensions and function were assessed at baseline and follow-up. A total of 50 patients with mainly functional MR (82%) were included. Non-sustained or sustained ventricular tachycardia (nsVT and/or sVT) occurred in 32% of patients and was reduced to 14% at follow-up (P = 0.01). Also, premature ventricular complex (PVC) burden ≥5% decreased from 16% to 4% (P = 0.04). Patients with persistent (n = 6) or new (n = 1) nsVT and/or sVT at follow-up showed a significant decrease in left ventricular ejection fraction from 38% (interquartile range 26-45%) to 33% (interquartile range 22-44%; P = 0.03).

CONCLUSIONS

In this prospective study, transcatheter mitral valve repair using MitraClip was associated with a reduced prevalence of ventricular arrhythmias. The subset of patients with persistent or new ventricular arrhythmias after MitraClip implantation showed progression of left ventricular dysfunction.

Transcatheter Mitral Valve Repair in Patients With and Without Cardiac Resynchronization Therapy: The COAPT Trial

BACKGROUND

In the COAPT trial (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation), treatment of heart failure (HF) patients with moderate-severe or severe secondary mitral regurgitation with transcatheter mitral valve repair (TMVr) using the MitraClip plus guideline-directed medical therapy (GDMT) reduced 2-year rates of HF hospitalization and all-cause mortality compared with GDMT alone. Whether the benefits of the MitraClip extend to patients with previously implanted cardiac resynchronization therapy (CRT) is unknown. We sought to examine the effect of prior CRT in patients enrolled in COAPT.

METHODS

Patients (N=614) with moderate-severe or severe secondary mitral regurgitation who remained symptomatic despite maximally tolerated doses of GDMT were randomized 1:1 to the MitraClip (TMVr arm) versus GDMT only (control arm). Outcomes were assessed according to prior CRT use.

RESULTS

Among 614 patients, 224 (36.5%) had prior CRT (115 and 109 randomized to TMVr and control, respectively) and 390 (63.5%) had no CRT (187 and 203 randomized to TMVr and control, respectively). Patients with CRT had similar 2-year rates of the composite of death or HF hospitalization compared with those without CRT (57.6% versus 55%, P=0.32). Death or HF hospitalization at 2 years was lower with TMVr versus control treatment in patients with prior CRT (48.6% versus 67.2%, hazard ratio, 0.60 [95% CI, 0.42-0.86]) and without CRT (42.5% versus 66.9%, hazard ratio, 0.52 [95% CI, 0.39-0.69]; adjusted P_interaction=0.23). The effects of TMVr with the MitraClip on reducing the 2-year rates of all-cause death (adjusted P_interaction=0.14) and HF hospitalization (adjusted P_interaction=0.82) were also consistent in patients with and without CRT as were improvements in quality-of-life and exercise capacity.

CONCLUSIONS

In the COAPT trial, TMVr with the MitraClip improved the 2-year prognosis of patients with HF and moderate-severe or severe secondary mitral regurgitation who remained symptomatic despite maximally tolerated GDMT, regardless of prior CRT implantation. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01626079.

The Role of Novel Transcatheter Procedures in Patients With Congenital Heart Disease

The development of percutaneous structural interventions in patients with acquired heart disease is happening at an exponential rate, and some of this technology is being used to treat patients with congenital heart disease. This review describes the pathophysiology of valvular abnormalities specific to congenital heart disease and discusses the application of structural procedures in this population. Although the overall experience has been encouraging, especially in high-risk patients, this article will highlight the reasons that a cautious approach to adoption of this technology is necessary in these patients.

The Use of MitraClip in Secondary Mitral Regurgitation and Heart Failure

Secondary (also known as functional) mitral regurgitation (MR) has increased substantially over the last several decades due to an increase in the prevalence of dilated cardiomyopathy (ischemic and non-ischemic). Mortality and morbidity in patients with dilated cardiomyopathy is much greater when associated with MR as compared to without MR. MR will result in further left ventricular (LV) volume overload, LV dilation, and pupillary muscle displacement resulting in deterioration of the severity of MR leading to a vicious cycle. Optimization of heart failure medical therapy, and cardiac resynchronization therapy for those that qualify, can improve severity of MR; however, significant MR will persist in certain patients. Transcatheter mitral valve repair to treat significant MR using the MitraClip (Abbott, Menlo Park, California), which grasps and coapts the posterior and anterior mitral valve leaflets, in appropriately selected patients with dilated cardiomyopathy and secondary MR has been shown to improve quality of life and prolong survival.

Functional mitral regurgitation and cardiac resynchronization therapy in the "era" of trans-catheter interventions: Is it time to move from a staged strategy to a tailored therapy?

Cardiac resynchronization therapy (CRT) has been associated to left ventricle (LV) remodelling, reduction of functional mitral regurgitation (FMR) and clinical improvement in patients with heart failure and reduced ejection fraction (HFrEF). The prevalence of significant FMR in patients with LV dyssynchrony that are candidate to CRT is up to 40%. Current approach in patients with FMR undergoing CRT consists of re-evaluation of the amount of FMR following a waiting period of at least 3 months after the implant. In case of persistent significant FMR despite CRT and guideline directed medical therapy, trancatheter Mitral Valve repair (TMVR) is an important option to improve quality of life and prognosis. This stepwise approach does not take into account the probability of the individual response to CRT and the availability of TMVR solutions that are safe and effective in high risk patients. We reviewed the effects of CRT on FMR, the prognostic role of persistence of FMR after CRT treatment and the impact of treatment of FMR in patients CRT non responders. We aimed to point out the limits of current step-wised approach in light on more recent evidence regarding FMR treatment. A new, "tailored" approached is proposed.

Percutaneous mitral valve repair in recurrent severe mitral valve regurgitation after mitral annuloplasty : MitraClip-in-the-ring as a complementary strategy

BACKGROUND

Patients with reduced left ventricular (LV) function undergoing coronary artery bypass graft surgery or/and aortic valve replacement occasionally show severe mitral valve (MV) regurgitation and thus also undergo surgical mitral annuloplasty. Over time, further deterioration of LV function and additional ischemic events cause recurrence of severe MV regurgitation due to the Carpentier IIIb morphology of the MV that is not adequately addressed by the previously implanted annuloplasty ring.

METHODS

Seven patients (Society of Thoracic Surgeons score: 7.5 ± 1.5%) with Carpentier type-IIIb recurrent severe MV regurgitation, having undergone prior cardiothoracic surgery (median: 40 months) including mitral annuloplasty, were treated with the MitraClip device.

RESULTS

MitraClip implantation resulted in significantly reduced MV regurgitation and improved New York Heart Association functional state, translating into an increased exercise capability and improved cardiac biomarkers. The morphology of the MV was adequately addressed without causing relevant MV stenosis, while the MV annulus area remained unaltered. The procedure was safe with a 30-day mortality rate of 0%.

CONCLUSION

MitraClip-in-the-ring is feasible and in principle safe for treating Carpentier type IIIb severe MV regurgitation after surgical MV repair using mitral annuloplasty. MitraClip-in-the-ring resulted in immediate amelioration of clinical symptoms and increased physical exercise capacity.

Numerical Simulations of MitraClip Placement: Clinical Implications

Mitral regurgitation (MR) is the most common type of valvular heart disease in patients over the age of 75 in the US. Despite the prevalence of mitral regurgitation in the elderly population, however, almost half of patients identified with moderate-severe MR are turned down for traditional open heart surgery due to frailty and other existing co-morbidities. MitraClip (MC) is a recent percutaneous approach to treat mitral regurgitation by placement of MC in the center of the mitral valve to reduce MR. There are currently no computational simulations to elucidate the role of MC on both the fluid and solid mechanics of the mitral valve. Here, we use the Smoothed Particle Hydrodynamics (SPH) approach to study various positional placements of the MC in the mitral valve and its impact on reducing MR. SPH is a particle based (meshless) approach that handles flow through narrow regions quite efficiently. Fluid and surrounding anatomical structure interactions is handled via contact and hence can be used for studying fluid-structure interaction problems such as blood flow with surrounding tissues/structure. This method is available as part of the Abaqus/Explicit solver. Regurgitation was initiated by removing targeted chordae tendineae that are attached to specified leaflets of the mitral valve and, subsequently, MC implants are placed in various locations, starting from the region near where the chordae tendineae were removed and moving away from the location towards the center of the valve. The MC implant location closest to where the chordae tendineae were removed showed the least amount of residual MR post-clip implantation amongst all other locations of MC implant considered. These findings have important implications for strategic placement of the MC depending on the etiology of MR to optimize clinical outcome.

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.

Contrasting Effects of Pharmacological, Procedural, and Surgical Interventions on Proportionate and Disproportionate Functional Mitral Regurgitation in Chronic Heart Failure

Two distinct pathways can lead to functional mitral regurgitation (MR) in patients with chronic heart failure and a reduced ejection fraction. When remodeling and enlargement of the left ventricle (LV) cause annular dilatation and tethering of the mitral valve leaflets, there is a linear relationship between LV end-diastolic volume and the effective regurgitant orifice area of the mitral valve. These patients, designated as having proportionate MR, respond favorably to treatments that lead to reversal of LV remodeling and a decrease in LV volumes (eg, neurohormonal antagonists and LV assist devices), but they may not benefit from interventions that are directed only at the mitral valve leaflets (eg, transcatheter mitral valve repair). In contrast, when ventricular dyssynchrony causes functional MR attributable to unequal contraction of the papillary muscles, the magnitude of regurgitation is greater than that predicted by LV volumes. These patients, designated as having severe but disproportionate MR, respond favorably to treatments that are directed to the mitral valve leaflets or their supporting structures (eg, cardiac resynchronization or transcatheter mitral valve repair), but they may derive little benefit from interventions that act only to reduce LV cavity size (eg, pharmacological treatments). This novel conceptual framework reflects the important interplay between LV geometry and mitral valve function in determining the clinical presentation of patients, and it allows characterization of the determinants of functional MR to guide the most appropriate therapy in the clinical setting.

Ischemic Mitral Regurgitation: Current Understanding and Surgical Options

Secondary, or functional, mitral regurgitation (MR) occurs with impaired coaptation of structurally normal valve leaflets due to abnormal structure and/or function of the left ventricle (LV). A leading cause of functional mitral regurgitation is ischemic cardiomyopathy, resulting in left ventricular dysfunction and subsequent congestive heart failure (CHF) and ischemic mitral regurgitation (IMR). The value of surgical or transcatheter correction of IMR remains controversial, since the underlying pathology of IMR is attributed to a dysfunctional left ventricle. However, even mild IMR has been shown to be harmful to CHF patients, as IMR is both a surrogate of advanced CHF and an independent contributor to CHF morbidity and mortality. While observational and randomized studies have examined surgical treatment of IMR with conflicting outcomes, additional well-designed randomized controlled trials should be performed to further clarify the optimal treatment for IMR. Additionally, close attention should be paid to the quality of interventions performed, as durable reduction in IMR provides the best hope of a positive clinical outcome. This review focuses on the pathophysiology of IMR, current evidence regarding surgical and transcatheter interventions, and future directions in management of IMR.

MitraClip device for patients with functional mitral valve regurgitation: A systematic review

BACKGROUND

MitraClip device is a novel therapeutic option for patients with degenerative mitral valve regurgitation. Nevertheless, several studies have also focused on the safety and efficacy of this method in functional mitral valve regurgitation (FMR).

AIM

To systematically review all original studies that provided mortality data among FMR patients treated with MitraClip.

MATERIALS AND METHODS

We conducted an in-depth literature search of 3 electronic databases (Medline, Scopus and Cochrane Library) in order to identify studies investigating the efficacy of MitraClip in FMR. Thirty-day and 12-month mortality after MitraClip implantation were the measured outcomes.

RESULTS

Twenty-eight studies, involving 2383 patients, were included. The phenotype of the studied population was characterized by clinical and echocardiographic parameters suggesting severe FMR (NYHA III-IV: 91%, MR≥3+: 98%) with high surgical risk (mean Euroscore: 24.6%). The Mitraclip device was successfully implanted in 95.8% of patients, resulting in a reduction of two or more degrees of MR. Thirty day and 12-month mortality rates were estimated to be 2.3% and 18.9%, respectively.

CONCLUSIONS

MitraClip appears to be a safe therapeutic option for patients with FMR who are considered to be at high surgical risk.

Percutaneous treatment of mitral regurgitation in patients with impaired ventricular function: Impact of intracardiac electronic devices (from the German Transcatheter Mitral Valve Interventions Registry)

OBJECTIVES

To identify prevalence/impact of previous implantation of cardiac electronic devices (CEDs), such as cardioverter defibrillator (ICD) and cardiac resynchronization (CRT), in a group of MitraClip (MC) candidates with LVEF < 30%.

BACKGROUND

MC therapy is nowadays often considered in patients with depressed left ventricular ejection fraction (LVEF%) and symptomatic severe secondary MR.

METHODS

Data from the German Transcatheter Mitral Valve Interventions (TRAMIs) registry were analyzed. Patients with pre-procedural LVEF <30% were selected and divided according to the presence of CEDs. Pre-procedural, peri-procedural, and 1-year follow-up data were analyzed.

RESULTS

Out of 689 MC patients, 235 had LVEF<30%. Of these, 23% (54/235) had CRT, 36.6% (86/235) ICD, and 40.4% (95/235) had no CEDs. Risk profile was similar (median STS score CRT 6.0 (IQR: 3.0-12.0); ICD 7.0 (IQR: 4.0-12.0); No-CED 6.5 (IQR: 2.0-10.0); p = 0.8). No procedural mortality was observed and hospital mortality was 5.6% in CRT, 2.3% in ICD, and 3.2% in No-CED (p = 0.5). At discharge, severe MV regurgitation was reported in 3.8% of CRT, 3.7% of ICD, and 1.1% of No-CED (p = 0.9). One year estimated survival (CRT 75.7%; ICD 75.8%; No-CED 78%; p = 0.94) and freedom from MACCE (CRT 73.6%; ICD 75.8%; No-CED 74.5%; p = 0.88) were similar.

CONCLUSIONS

A third of patients have been already submitted to CEDs implantation at time of referral for MC therapy and 40% of those with severely depressed LVEF% arrive to MC therapy before ICD/CRT implantation. The presence of CED does not impair acute MC therapy success. Mid-term follow-up outcomes are similar in patients with and without CEDs.

Effect of Functional Mitral Regurgitation on Outcome in Patients Receiving Cardiac Resynchronization Therapy for Heart Failure

Functional mitral regurgitation (FMR) is common in heart failure (HF), and negatively impacts prognosis. Cardiac resynchronization therapy (CRT) can improve FMR, but the long-term changes in and impact of FMR after CRT are still unclear. The present study investigated the prevalence, evolution and impact on mortality of FMR before and after CRT in patients with HF. A total of 1,313 patients (66 ± 11 years, 77% male, 59% ischemic heart disease) treated with CRT were evaluated. Patients were divided into 4 groups of FMR according to the evolution at 6 months after CRT: no or mild FMR at baseline which remained unchanged at 6 months (grade 0-1 FMR unchanged, n = 609 [51%]), no or mild FMR which worsened to moderate to severe (grade 0-1 FMR worsened, n = 66 [6%)]), moderate to severe FMR which improved to no or mild (grade 2-4 improved, n = 209 [18%]), and moderate to severe FMR which remained unchanged (grade 2-4 unchanged, n = 309 [26%]). Over a mean follow-up of 51 ± 38 months, 297 (25%) patients died. Those with baseline FMR grade 0-1 which remained unchanged at 6-month follow-up, as well as baseline FMR grade 2-4 which improved, had lower mortality rates than patients with 6-month FMR grade 2-4 regardless of baseline FMR grade (p <0.001). Baseline FMR grade 2-4 that remained unchanged at 6-month follow-up was associated with increased mortality, independent of the clinical and left ventricular volumetric responses to CRT (hazard ratio, 1.77; 95% confidence interval, 1.41-2.22, p <0.001). In conclusion, moderate to severe FMR at baseline which remains unchanged at 6 months after CRT implantation is strongly associated with long-term mortality in patients with HF.

Left ventricular reverse remodelling predicts long-term outcomes in patients with functional mitral regurgitation undergoing MitraClip therapy: results from a multicentre registry

AIMS

To explore whether left ventricular reverse remodelling (LVRR) is a predictor of outcomes in patients with functional mitral regurgitation (FMR) undergoing MitraClip procedure.

METHODS AND RESULTS

We analysed 184 consecutive patients with FMR who underwent successful MitraClip procedure. LVRR was defined as a reduction in left ventricular end-systolic volume ≥ 10% from baseline to 6 months. LVRR was observed in 79 (42.9%) patients. Compared with non-LVRR, LVRR patients were more likely to be females, less likely to have an ischaemic aetiology of mitral regurgitation or a prior (<6 months) heart failure (HF) hospitalization, and had smaller left ventricular dimensions. New York Heart Association class improved from baseline up to 1-year follow-up in both groups. Higher rates of overall survival (87.3% vs. 75.2%, P = 0.039), freedom from HF hospitalization (77.2% vs. 60%, P = 0.020), and freedom from the composite endpoint (cardiovascular mortality or HF hospitalization) (74.7% vs. 55.2%; P = 0.012) were observed in LVRR vs. non-LVRR patients at 2-year follow-up. LVRR was associated with a significant reduction of the adjusted relative risk of mortality, HF hospitalization and composite endpoint [hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.20-0.96, P = 0.040; HR 0.55; 95% CI 0.32-0.97, P = 0.038; and HR 0.54; 95% CI 0.32-0.92, P = 0.023, respectively]. Female gender, absence of diabetes, freedom from prior HF hospitalization, non-ischaemic aetiology of mitral regurgitation, and left ventricular end-diastolic diameter < 75 mm were found to be independent predictors of LVRR.

CONCLUSIONS

Left ventricular reverse remodelling is associated with better long-term outcomes in patients with FMR successfully treated with MitraClip. A careful patient selection may be useful as specific baseline features predict favourable left ventricular remodelling. [Correction added on 17 January 2019, after online publication: the preceding sentence has been changed.].

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

MitraClip in Patients With Mitral Regurgitation and Left Ventricular Ejection Fraction <30% - Potential Implications for the Treatment of Patients in Japan

BACKGROUND

The effect of the unique Japanese indication for MitraClip based on left ventricular ejection fraction (LVEF) is unclear. Methods and Results: We analyzed 874 patients who underwent MitraClip because of mitral regurgitation (MR) and compared the characteristics and outcomes between patients with LVEF <30% and ≥30%. Patients with LVEF ≤30% accounted for 33% of the study population and had a higher prevalence of functional MR. Severity of MR after MitraClip was comparable, and LVEF <30% did not independently affect survival.

CONCLUSIONS

Japanese unique indication based on LVEF may exclude one third of patients who were treated with MitraClip in Europe.