Interventional vs. surgical mitral valve therapy

Percutaneous treatment of mitral valve regurgitation: Where do we stand?

Surgery has been the standard of care for mitral valve diseases to date. In the last fifteen years, due to increased aging of the population, with a great number of patients being high-risk for surgical treatment, transcatheter treatments for mitral valve disease have greatly developed. Further development and expansion of transcatheter treatments are expected. However, some limitations remain, such as efficacy and durability, which impact the widespread use of these devices.

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.

Intraprocedural assessment of mitral regurgitation during the mitraclip procedure: Impact of continuous left atrial pressure monitoring

INTRODUCTION

Intraprocedural assessment of mitral regurgitation (MR) is a challenging issue during the MitraClip procedure, which might influence not only the position but also the number of MitraClips implanted. Though transesophageal echocardiography (TEE) is the predominant tool used during the MitraClip procedure, MR assessment might be facilitated by a multimodality approach including continuous and simultaneous determination of left atrial and left ventricular (LV) pressure.

METHODS

86 consecutive patients (76.5 ± 8 years) who qualified for the MitraClip procedure were included into the study. In all patients, the multimodal assessment of MR (TEE, LV angiogram, TEE bubble evaluation, left atrial (LA) pressure => MitraScore) was performed after introducing the MitraClip guide catheter. In the first 42 patients (group A, no CAP), left atrial (LA) pressure (peak pressure of V-wave) was determined only before and after MitraClip implantation, whereas, in the subsequent 44 patients (group B, with CAP), continuous left atrial pressure monitoring (CAP) was performed.

RESULTS

Patients with CAP (group B) had similar total procedural durations and no increase in the complication rate. MitraScore decreased from 10.5 to 3.5 in group A compared to 10.7 to *2.8 in group B (*P = 0.021 vs. group B). Whether the significant improvement of intraprocedural MR in group B translated into superior MR reduction in the conscious patient, was analyzed by transthoracic echocardiography (TTE) in a blinded fashion. Again MR reduction was significantly greater (P = 0.03) in group B (MR grade 2.8 to 0.9) as compared to group A (MR grade 2.8 to 1.3) and 2D vena contracta decreased from 0.54 ± 0.15 cm to 0.17 ± 0.10 in group B compared to group A (0.56 ± 0.19 cm to *0.23 ± 0.12; *P = 0.01 vs. group B).

CONCLUSIONS

Multimodality assessment of intraprocedural MR supported by continuous left atrial pressure monitoring was associated with superior intraprocedural results translating into improved MR reduction also at the end of the hospital stay. © 2016 Wiley Periodicals, Inc.

Percutaneous Mitral Annuloplasty

Percutaneous mitral valve therapies are emerging as an alternative option for high-risk patients who are not good candidates for conventional open-heart surgery. Recently, multiple technologies and diversified approaches have been developed and are under clinical study or in preclinical development. This article on transcatheter mitral annuloplasty devices, describes the different technologies, and reports on the initial clinical and preclinical experiences.

[Mitral valve interventions: Where do we stand?]

Mitral valve regurgitation (MR) with resulting heart failure is one of the most prevalent types of valvular heart disease. Currently, various approaches to catheter-based therapy of MR are already available for patients deemed to be at high-risk for surgery. Most experience has been gained with the MitraClip® system. Technological developments in the field of catheter-based treatment of MR is advancing at a rapid pace, with treatment modalities suited for patients with both primary and secondary MR. Annuloplasty is the surgical gold standard, particularly for patients with secondary MR. For catheter-based therapy of secondary MR a distinction is made between indirect and direct annuloplasty, with the latter most closely corresponding to surgical ring implantation. Catheter-based mitral valve replacement is technically feasible at present; however, experience is still limited and only few reports have been published. Technological development is markedly slower than in the field of transcatheter aortic valve replacement, predominantly owing to the far more complex structure of the mitral valve. Positive experience has already been gained with catheter-based implantation of prostheses designed for the aortic valve into degenerated mitral valve bioprostheses and failed surgical mitral annuloplasty rings (valve-in-valve and valve-in-ring implantation). Further approaches to catheter-based treatment of MR in high-risk surgical patients are expected in the future.

The future of transcatheter mitral valve interventions: competitive or complementary role of repair vs. replacement?

Transcatheter mitral interventions has been developed to address an unmet clinical need and may be an alternative therapeutic option to surgery with the intent to provide symptomatic and prognostic benefit. Beyond MitraClip therapy, alternative repair technologies are being developed to expand the transcatheter intervention armamentarium. Recently, the feasibility of transcatheter mitral valve implantation in native non-calcified valves has been reported in very high-risk patients. Acknowledging the lack of scientific evidence to date, it is difficult to predict what the ultimate future role of transcatheter mitral valve interventions will be. The purpose of the present report is to review the current state-of-the-art of mitral valve intervention, and to identify the potential future scenarios, which might benefit most from the transcatheter repair and replacement devices under development.

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

BACKGROUND

Mitral regurgitation (MR) is the second most common valvular heart disease after aortic stenosis. Without intervention, prognosis is poor in patients with severe symptomatic MR. While surgical repair is recommended for many patients with severe degenerative MR (DMR), as many as 49% of patients do not qualify as they are at high surgical risk. Furthermore, surgical correction for functional MR (FMR) is controversial with suboptimal outcomes and significant perioperative mortality. The percutaneous MitraClip implantation can be seen as a viable option in high surgical risk patients. The purpose of this meta-analysis is to compare the safety, clinical efficacy, and survival outcomes of MitraClip implantation with surgical correction of severe MR.

METHODS

Six electronic databases were searched for original published studies from January 2000 to August 2013. Two reviewers independently appraised studies, using a standard form, and extracted data on methodology, quality criteria, and outcome measures. All data were extracted and tabulated from the relevant articles' texts, tables, and figures and checked by another reviewer.

RESULTS

Overall 435 publications were identified. After applying selection criteria and removing serial publications with accumulating number of patients or increased length of follow-up, four publications with the most complete dataset were included for quality appraisal and data extraction. There was one randomized controlled trial (RCT) and three prospective observational studies. At baseline, patients in the MitraClip group were significantly older (P=0.01), had significantly lower LVEF (P=0.03) and significantly higher EuroSCORE (P<0.0001). The number of patients with post-procedure residual MR severity >2 was significantly higher in the MitraClip group compared to the surgical group (17.2% vs. 0.4%; P<0.0001). 30-day mortality was not statistically significant (1.7% vs. 3.5%; P=0.54), nor were neurological events (0.85% vs. 1.74%; P=0.43), reoperations for failed MV procedures (2% vs. 1%; P=0.56), NYHA Class III/IV (5.7% vs. 11.3; P=0.42) and mortality at 12 months (7.4% vs. 7.3%; P=0.66).

CONCLUSIONS

Despite a higher risk profile in the MitraClip patients compared to surgical intervention, the clinical outcomes were similar although surgery was more effective in reducing MR in the early post procedure period. We conclude the non-inferiority of the MitraClip as a treatment option for severe, symptomatic MR in comparison to conventional valvular surgery.