A meta-analysis of MitraClip system versus surgery for treatment of severe mitral regurgitation

Comparative Efficacy and Safety of Transcatheter Mitral Valve Repair Versus Mitral-valve Surgery in Elderly Patients With Mitral Regurgitation: A Systematic Review and Meta-analysis

Objectives

Mitral valve surgery is the reference treatment for severe symptomatic mitral regurgitation (MR). Percutaneous mitral valve interventions, such as the MitraClip procedure, offer an alternative, particularly for high-risk patients. The aim of this systematic review and meta-analysis was to analyze the safety and effectiveness of transcatheter mitral valve repair (TMVR) compared to surgical mitral valve repair or replacement (SMVR) in elderly patients with mitral regurgitation.

Methods

We searched PubMed, Scopus, Ovid, EBSCO, and ProQuest through July 2024. Eligible studies were randomized controlled trials and observational comparative studies of TMVR versus SMVR for patients with MR, reporting outcomes such as all-cause mortality, MR recurrence, stroke, myocardial infarction, and length of stay (LOS). Statistical analyses were performed using RevMan.

Results

Our search identified 3166 records, with 2756 screened and 21 studies included after review. The studies, comprising 20 retrospective cohorts and 1 randomized controlled trial with 20,900 patients, compared TMVR to SMVR. TMVR patients were significantly older than SMVR patients (MD 3.44 years; P < 0.00001). Mortality rates were similar at 30 days (relative risk (RR) 1.08; P = 0.79) and one year (RR 1.27; P = 0.18), but SMVR showed lower mortality at three years (RR 1.82; P = 0.006). SMVR also significantly reduced MR ≥ 3+ recurrence at 30 days (RR 6.95; P < 0.00001), one year (RR 3.31; P = 0.0001), and three years (RR 4.37; P < 0.00001). TMVR was associated with higher myocardial infarction rates (RR 1.58; P = 0.02) but reduced LOS (MD -4.88 days; P < 0.00001). Sensitivity analysis showed consistent results for recurrence of MR ≥ 3+ and variable outcomes for other metrics. Evidence of publication bias was noted for mortality at 30 days and LOS.

Conclusion

While TMVR with the MitraClip offers shorter hospital stays and is less invasive, SMVR provides better long-term survival and lower MR recurrence rates, emphasizing the need for a tailored approach based on patient risk profiles.

Effects of Transcatheter Mitral Valve Repair Using MitraClip® Device on Sleep Disordered Breathing in Patients with Mitral Valve Regurgitation

Sleep disordered breathing (SDB) is common among patients with valvular heart disease, and successful valve surgery could reduce SDB severity. However, data about the effects of transcatheter mitral valve repair on SDB are scarce. Therefore, mitral regurgitation (MR) patients undergoing MitraClip-placement were prospectively enrolled. Before MitraClip-placement, daytime sleepiness and sleep quality were assessed using the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI), respectively; and all patients underwent SDB screening using five-channel respiratory polygraphy. After 3-6 months, patients had a similar reassessment including: ESS, PSQI, and respiratory polygraphy. 67 patients were included (77 ± 8years). Despite normal sleepiness scores, 41 patients (61%) had SDB with apnea-hypopnea-index (AHI) ≥ 15 h before MitraClip-placement, of whom only three patients had known SDB previously. Compared to patients without SDB, patients with SDB had similar sleepiness scores but higher NT-proBNP values at baseline (4325 vs. 1520 pg/mL, p < 0.001). At follow-up, there were significant AHI improvements among patients with SDB (p = 0.013). However, there were no significant sleepiness score changes. In conclusion, the prevalence of SDB among MitraClip candidates is very high even in those without daytime sleepiness. MR patients with SDB have higher NT-proBNP values, which may reflect a worse prognosis. MitraClip-placement may improve the underlying SDB, which could be an additional benefit of the procedure.

Percutaneous Mitral Valve Repair with the MitraClip System in the Current Clinical Practice

Severe mitral valve regurgitation (MR) carries a significant burden both in prognosis and quality of life of patients, as well as on healthcare systems, with high rates of hospitalization for heart failure. While mitral valve surgery constitutes the first-line treatment option for primary MR in suitable patients, surgical treatment for secondary severe MR remains controversial, with a substantial lack of evidence on a survival benefit. In recent decades, percutaneous mitral valve repair has emerged as an alternative treatment for patients deemed not suitable for surgery. Among several devices under development or evaluation, the MitraClip system is the most widespread and is supported by the strongest evidence. While the role of MitraClip in patients with chronic primary MR who are not deemed suitable for surgery is well established, with consistent data showing improvement in both prognosis and quality of life, MitraClip treatment in secondary MR is a rapidly evolving field. Two recent randomized clinical trials generated apparently controversial results but actually provided an interesting pathophysiologic frame that could help discerning patients who will benefit from the procedure versus patients who will not. In this review, we will discuss current treatment options for mitral regurgitation, focusing on percutaneous mitral valve repair with the MitraClip system.

Pseudomonas MitraClip® endocarditis: A case report and review of literature

Endocarditis from Pseudomonas aeruginosa is a rare cause of endocarditis with most of those cases in patients with intravenous drug abuse. The MitraClip® is a relatively new device with few incidences of endocarditis in the literature. Here we present the first reported case of pseudomonal endocarditis of a MitraClip® in a non-IV drug user.

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.

Interrelationship Between Kidney Function and Percutaneous Mitral Valve Interventions: A Comprehensive Review

Percutaneous mitral valve repair is emerging as a reasonable alternative especially in those with an unfavorable surgical risk profile in the repair of mitral regurgitation. At this time, our understanding of the effects of underlying renal dysfunction on outcomes with percutaneous mitral valve repair and the effects of this procedure itself on renal function is evolving, as more data emerges in this field. The current evidence suggests that the correction of mitral regurgitation via percutaneous mitral valve repair is associated with some degree of improvement in cardiac function, hemodynamics and renal function. The improvement in renal function was more significant for those with greater renal dysfunction at baseline. The presence of Chronic Kidney Disease (CKD) in turn has been associated with poor long-term outcomes including increased mortality and hospitalization among patients who undergo percutaneous mitral valve repair. This was true regardless of the degree of improvement in GFR post repair advanced CKD. The adverse impact of CKD on long-term outcomes was consistent across all studies and was more prominent in those with GFR<30 mL/min/1.73 m². It is clear that from these contrasting evidences of improved renal function post mitral valve repair but poor long-term outcomes including increased mortality in patients with CKD, that proper patient selection for percutaneous mitral valve repair is key. There is a need to have better-standardized criteria for patients who should qualify to have percutaneous mitral valve replacement with Mitraclip. In this new era of percutaneous mitral valve repair, much work needs to be done to optimize long-term patient outcomes.

Failed MitraClip therapy: surgical revision in high-risk patients

Background

MitraClip implantation is a valid interventional option that offers acceptable short-term results. Surgery after failed MitraClip procedures remains challenging in high-risk patients. The data on these cases are limited by the small sample numbers.

Aim

The aim of our study is to show, that mitral valve surgery could be possible and more advantageous, even in high-risk patients.

Methods

Between 2010 and 2016, nine patients underwent mitral valve surgery after failed MitraClip therapy at our institution.

Results

The patients’ ages ranged from 19 to 75 years (mean: 61.2 ± 19.6 years). The median interval between the MitraClip intervention and surgical revision was 45 days (range: 0 to 1087 days). In eight of nine patients, the MitraClip intervention was initially successful and the  mitral regurgitation was reduced. Only one patient had undergone cardiac surgery previously.

Intra-operatively, leaflet perforation or rupture, MitraClip detachment, and chordal or papillary muscle rupture were potentially the causes of recurrent mitral regurgitation.

There were three early deaths. One year after surgery, the six remaining patients were alive.

Conclusions

Mitral valve surgery can be successfully performed after failed MitraClip therapy in high-risk patients. The initial indication for MitraClip therapy should be considered carefully for possible surgical repair.

A meta-analysis of MitraClip combined with medical therapy vs. medical therapy alone for treatment of mitral regurgitation in heart failure patients

AIMS

Survival benefit of percutaneous mitral valve repair with the MitraClip over conservative treatment of functional mitral regurgitation (MR) remains unclear. The purpose of this meta-analysis is to compare survival outcomes of MitraClip with those of medical therapy in patients with functional MR.

METHODS AND RESULTS

A comprehensive literature search of PubMed, MEDLINE, and Google Scholar was conducted including studies evaluating MitraClip vs. medical therapy with multivariate adjustment and with >80% of patients with functional MR. Death from any cause was the primary endpoint, while freedom from readmission was the secondary one, evaluated with random effects. These analyses were performed at study level and at patient level including only functional MR when available, evaluating the effect of MitraClip in different subgroups according to age, ischaemic aetiology, presence of implantable cardioverter defibrillator/cardiac resynchronization therapy, and left ventricular ejection fraction and volumes. We identified six eligible observational studies including 2121 participants who were treated with MitraClip (n = 833) or conservative therapy (n = 1288). Clinical follow-up was documented at a median of 400 days. At study-level analysis, MitraClip, when compared with medical therapy (P = 0.005), was associated with significant reduction of death (P = 0.002) and of readmission due to cardiac disease. At patient-level analysis, including 344 patients, MitraClip confirmed robust survival benefit over medical therapy for all patients with functional MR and among the most important subgroups.

CONCLUSIONS

Compared with conservative treatment, MitraClip is associated with a significant survival benefit. Importantly, this superiority is particularly pronounced among patients with functional MR and across all the main subgroups.

Robotic surgery is the optimal approach for mitral surgery

This report presented an overview of the patient selection, technical considerations and clinical evidence for robotic mitral valve surgery. A review of comparative outcomes to medical therapy, sternotomy approach, and the MitraClip device suggested that robotic mitral valve surgery is safe and effective in specialized centres. Potential benefits include a reliable and durable repair, with reduced perioperative morbidity and improved quality of life. Future studies should aim to delineate mid- and long-term clinical and echocardiographic outcomes following robotic mitral valve repair compared to the conventional sternotomy approach.

Echo-Doppler determinants of outcomes in patients with unoperated significant mitral regurgitation in current era

Objective

One-half of patients with severe symptomatic mitral regurgitation (MR) do not undergo surgery due to comorbidities. We evaluated prognosticators of outcomes in patients with unoperated significant MR.

Methods

In this observational study, we retrospectively evaluated medical records of 75 consecutive patients with unoperated significant MR.

Results

All-cause mortality was 39% at 5 years. Non-survivors (n=29) versus survivors (n=46) were: older (77±9.8 vs 68±14, p=0.006), had higher New York Heart Association (NYHA) class (2.7±0.8 vs 2.3±0.8, p=0.037), higher brain natriuretic peptide (1157±717 vs 427±502 pg/mL, p=0.024, n=18), more coronary artery disease (61% vs 35%, p=0.031), more frequent left ventricular ejection fraction <50% (20.7% vs 4.3%, p=0.026), more functional MR (41% vs 22%, p=0.069), higher mitral E/E^′ (12.7±4.6 vs 9.8±4, p=0.008), higher pulmonary artery systolic pressure (PASP; 52.6±18.7 vs 36.7±14, p <0.001), more ≥3+ tricuspid regurgitation (28% vs 4%, p=0.005) and more right ventricular dysfunction (26% vs 6%, p=0.035). Significant predictors of 5-year mortality were PASP (p=0.001) and E/E^′ (p=0.011) using multivariate regression analysis.

Conclusions

Patients with unoperated significant MR have high mortality. Elevated PASP and mitral E/E^′ were the most significant predictors of 5-year survival in patients with unoperated significant MR. Current American College of Cardiology (ACC)/American Heart Association (AHA) guidelines provide a limited incorporation of echo-Doppler parameters in the preoperative risk stratification of patients with severe MR.

Annulus Tension on the Tricuspid Valve: An In-Vitro Study

Annulus tension (AT) is defined as leaflet tension per unit length of the annulus circumference. AT was investigated to understand tricuspid valve (TV) annulus mechanics. Ten porcine TVs were mounted on a right ventricle rig with an annulus plate to simulate TV closure. The TVs were mounted on the annulus plate in a normal and dilated TV annulus sizes, and closed under transvalvular pressure of 40 mmHg with the annulus held peripherally by wires. Anterior papillary muscle (PM) and septal PM were displaced in the dilated annulus. Wire forces were measured, and ATs (N/m) were calculated. Clover repair was performed in the dilated TV state subsequently, and AT was calculated again. A one-way ANOVA and Tukey's HSD test were used to test significances between the different TV states along each annulus segment with p < 0.05. Average ATs for the normal annulus, dilated annulus, and clover repair were 10.75 ± 1.87, 28.81 ± 10.51, and 26.93 ± 11.44 N/m, respectively. Septal annulus segments had the highest ATs when compared to the other segments. For the clover repair, there were no significant changes in AT values. ATs and leaflet forces increased roughly 3-4 times with annulus dilation. AT decelerates annulus dilation as previously shown in the mitral valve. Clover repair does not prevent further annulus dilation by AT change and should be accompanied by annuloplasty. AT improves annulus contraction during a cardiac cycle and should be considered when designing annuloplasty in the future.

[Structure and function of the mitral valve. Eligibility criteria for surgical and interventional approaches]

Mitral valve disease, especially severe mitral valve insufficiency, is an increasing issue in our population. Older patients with multiple comorbidities in particular are often denied surgery due to an increased perioperative risk. Because conservative medical treatment of mitral valve disease is often unsatisfactory, interventional techniques to treat mitral valve disease have emerged in recent years as serious alternatives to surgical treatment. Innovative developments in cardiovascular imaging have opened up new ways of looking at the mitral valve for improved diagnostic and therapeutic management of patients with mitral valve disease. These advantages of imaging are important for correct patient selection with either surgical or interventional strategies. This review describes the diagnostic capabilities of echocardiographic techniques for a precise diagnosis of the mitral valve structure and function for planning and performing interventional or surgical procedures.

Percutaneous mitral valve repair: A new treatment for mitral regurgitation

Mitral valve disease affects more than 4 million people in the United States. The gold standard of treatment in these patients is surgical repair or replacement of the valve with a prosthesis. The MitraClip (Abbott Vascular, Menlo Park, CA) is a new technology, which offers an alternative to open surgical repair or replacement via a minimally invasive route. We present an evidence-based clinical update that provides an overview of this technology as it relates to managing patients with significant mitral regurgitation. This review article is particularly useful to noninterventional cardiologists and interventional cardiologists who will be managing patients with this novel technology in increased volumes over the next decade but who do not perform this procedure.

The Evolving Role of Percutaneous Mitral Valve Repair

BACKGROUND

Mitral regurgitation (MR) is the second leading cause of valvular heart disease in the United States behind aortic stenosis. The percutaneous repair of the mitral valve (MitraClip, Abbott, Inc.) has been approved in the United States since 2013 as an alternative to traditional mitral valve surgery. However, many questions are left unanswered about when to perform this procedure and whom to perform it on.

METHODS

We reviewed major published literature on the MitraClip from 2003-2016 to help guide clinical decision-making. A PubMed search was conducted using the phrase "mitraclip" or "percutaneous mitral valve repair" to identify relevant articles pertaining to the clip as well as surgical valve repair.

RESULTS

The clinical trials EVEREST I and EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) demonstrated the safety and efficacy of the MitraClip but did not prove its superiority to surgical repair in the population studied. Numerous subsequent registries have suggested that the success of the MitraClip varies with the patient population studied. The currently enrolling Cardiovascular Outcomes for Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional MR (COAPT) trial hopes to answer some of these questions.

CONCLUSION

The MitraClip is a new and exciting technology for percutaneously treating disease processes traditionally managed with surgery. The future of the clip and its patient population is dependent on further studies.

An intriguing case report of functional mitral regurgitation treated with MitraClip

Functional mitral regurgitation (FMR) is frequent in patients with heart failure (HF). It develops as a consequence of left ventricle (LV) geometry alterations, causing imbalance between increased tethering forces and decreased closing forces exerted on the mitral valve apparatus during systole.FMR is known to change at rest and during effort, due to preload-afterload changes, myocardial ischemia, and/or LV dysfunction. Despite optimized medical therapy, an FMR can be responsible of shortness of breath limiting quality of life and decompensation. In this report, we present a case of dynamic FMR treated with MitraClip.MitraClip implantation is a successful and innovative opportunity for HF patients with FMR.

[Interventional therapy of heart valve diseases: future perspectives]

Transcatheter procedures have been adopted as novel treatment strategy for patients with valvular heart disease, particularly for those who are inoperable or at high risk for surgical valve procedures. Significant technological advances have resulted in an improvement of devices for transcatheter aortic valve replacement (TAVI) with downsizing of crossing profiles, reduction in the rate of paravalvular leakage and conduction abnormalities as well as a lower short- and mid-term mortality and a higher patient acceptance. In the near future, TAVI may potentially develop as first-line treatment for the majority of patients with aortic valve disease. For patients with mitral and pulmonary stenosis, balloon valvuloplasty is effective and well established and should be preferred over valve replacement, last but not least also for economic reasons. For treatment of mitral regurgitation, several transcatheter devices aiming to restore or replace mitral valve function are currently under investigation. This review summarizes the current state of interventional treatment of valvular heart disease along with implications for the future.

Multicenter evaluation of high-risk mitral valve operations: implications for novel transcatheter valve therapies

BACKGROUND

The MitraClip REALISM (Abbott Vascular, Menlo Park, CA) trial included several inclusion criteria to identify patients at high risk for conventional mitral valve (MV) surgery. This study evaluated contemporary surgical outcomes for high-risk surgical patients who met these defined criteria to serve as a benchmark to evaluate appropriateness in treatment allocation between surgical and percutaneous MV repair.

METHODS

A statewide Society for Thoracic Surgeons (STS) database was queried for patients undergoing isolated mitral valve surgery over a 12-year study period from 17 different hospitals. Patients were stratified into high-risk (HR) versus non-high-risk (non-HR) cohorts based upon clinical criteria similar to those utilized in the REALISM trial. Mixed effects multivariable regression modeling was used to evaluate study endpoints including mortality, morbidity, and resource utilization.

RESULTS

Of 2,440 isolated mitral operations, 29% (n = 698) were HR per REALISM criteria. Median STS Predicted Risk of Mortality (PROM) for HR patients was 6.6% compared with 1.6% for non-HR patients (p < 0.001). The HR patients more commonly underwent MV replacement as well as urgent (30% vs 19%, p < 0.001) operations. High-risk patients incurred higher morbidity and mortality (7% vs 1.6%) with longer intensive care unit (48 vs 41 hours) and hospital stays (7 vs 6 days, all p < 0.001). Among REALISM criteria, STS PROM 12% or greater and high-risk STS criteria were the only criteria associated with mortality.

CONCLUSIONS

Select REALISM criteria, including reoperation with patent grafts and functional MR with ejection fraction less than 0.40, may not identify patients truly at high risk of death with surgery. In addition to conventional STS criteria, risk assessment by surgeons is essential to direct appropriate treatment allocation for high-risk mitral disease.