Established interventions for mitral valve regurgitation. Current evidence

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.

Transaortic repair of concomitant mitral insufficiency in patients with critical aortic stenosis undergoing aortic valvular replacement

Background

In this study, we present operation technique and outcomes of transaortic mitral valve repair in high-risk patients undergoing aortic valve replacement due to severe aortic stenosis.

Methods

Between January 2005 and March 2016, a total of 11 patients (7 females, 4 males; mean age 71.2±4.1 years; range, 65 to 77 years) with severe aortic valve stenosis (aortic valve area <1 cm2 or aortic valve area index <0.6 cm2/m2) and concomitant moderate or severe mitral regurgitation (non-ischemic, regurgitant jet origin between A2-P2 portions) secondary to left ventricular dysfunction (EuroSCORE logistic score >5%, left ventricular ejection fraction <30%) who were operated were retrospectively analyzed. Aortic valve replacement and transaortic mitral edge-to-edge repair was applied to all patients. Operations were performed through sternotomy, cardiopulmonary bypass, and bicaval venous return. Transesophageal echocardiography was used to evaluate mitral valve before surgery and valve functions after surgery. Postoperative course of all patients was monitored, and postoperative complications were recorded.

Results

The mean preoperative ejection fraction was 24.5±4.1% and the mean transaortic pressure gradient was 35.8±4.8 mmHg. The mean aortic cross-clamp time was 62.09±10.1 (range, 43 to 76) min and the median cardiopulmonary bypass time was 90.1±11.9 (range, 66 to 114) min. No hospital mortality was observed. In the postoperative period, two patients experienced renal insufficiency. Hemofiltration was initiated in these patients and no dialysis was required at two weeks. One patient had postoperative atrial fibrillation and one patient had pericardial effusion leading to cardiac tamponade and this patient underwent reoperation. The patients were followed up for a mean of four years and control echocardiography didn"t detect increase in mitral regurgitation degree.

Conclusion

Transaortic edge-to-edge mitral valve repair can be used in high-risk patients undergoing aortic valve replacement. This technique is feasible with shorter cross-clamp time and can reduce mortality and morbidity in selected high-risk patients.

A workflow for patient-specific fluid-structure interaction analysis of the mitral valve: A proof of concept on a mitral regurgitation case

The mechanics of the mitral valve (MV) are the result of the interaction of different anatomical structures complexly arranged within the left heart (LH), with the blood flow. MV structure abnormalities might cause valve regurgitation which in turn can lead to heart failure. Patient-specific computational models of the MV could provide a personalised understanding of MV mechanics, dysfunctions and possible interventions. In this study, we propose a semi-automatic pipeline for MV modelling based on the integration of state-of-the-art medical imaging, i.e. cardiac magnetic resonance (CMR) and 3D transoesophageal-echocardiogram (TOE) with fluid-structure interaction (FSI) simulations. An FSI model of a patient with MV regurgitation was implemented using the finite element (FE) method and smoothed particle hydrodynamics (SPH). Our study showed the feasibility of combining image information and computer simulations to reproduce patient-specific MV mechanics as seen on medical images, and the potential for efficient in-silico studies of MV disease, personalised treatments and device design.

1-Year Outcomes After Edge-to-Edge Valve Repair for Symptomatic Tricuspid Regurgitation: Results From the TriValve Registry

OBJECTIVES

The purpose of this study was to evaluate procedural and 1-year clinical and echocardiographic outcomes of patients treated with tricuspid edge-to-edge repair.

BACKGROUND

Transcatheter edge-to-edge repair has been successfully performed in selected patients with symptomatic tricuspid regurgitation (TR) and high risk for surgery, but outcome data are sparse.

METHODS

This analysis of the multicenter international TriValve (Transcatheter Tricuspid Valve Therapies) registry included 249 patients with severe TR treated with edge-to-edge repair in compassionate and/or off-label use. Clinical and echocardiographic outcomes were prospectively collected and retrospectively analyzed.

RESULTS

In 249 patients (mean age 77 ± 9 years; European System for Cardiac Operative Risk Evaluation II score 6.4% [interquartile range: 3.9% to 13.9%]), a successful procedure with TR reduction to grade ≤2+ was achieved in 77% by placement of 2 ± 1 tricuspid clips. Concomitant treatment of severe TR and mitral regurgitation was performed in 52% of patients. At 1-year follow-up, significant and durable improvements in TR severity (TR ≤2+ in 72% of patients) and New York Heart Association functional class (≤II in 69% of patients) were observed. All-cause mortality was 20%, and the combined rate of mortality and unplanned hospitalization for heart failure was 35%. Predictors of procedural failure included effective regurgitant orifice area, tricuspid coaptation gap, tricuspid tenting area, and absence of central or anteroseptal TR jet location. Predictors of 1-year mortality were procedural failure, worsening kidney function, and absence of sinus rhythm.

CONCLUSIONS

Transcatheter tricuspid edge-to-edge repair can achieve TR reduction at 1 year, resulting in significant clinical improvement. Predictors of procedural failure and 1-year mortality identified here may help select patients who will benefit most from this therapy.

[Cardioband®: Where do we stand, who are suitable patients?]

Functional mitral regurgitation (FMR) is characterized by a dilatation of the mitral valve annulus resulting in an insufficient adaptation of the anterior and posterior mitral valve leaflets and/or severe tethering of the leaflets due to dilatation of the left ventricle. The Cardioband® system was introduced in 2015 and is a catheter-based direct mitral valve annuloplasty procedure for treatment of FMR. In the European CE approval study 60 patients with moderate or severe FMR were analyzed per protocol. There were no device or procedure-related deaths. The technical success rate of the procedure, defined as successful implantation and tightening was 97%. At 1 year, the overall survival and survival free of hospital readmission for heart failure were 87% and 66%, respectively. Currently, various interventional treatment procedures are available, such as the edge-to-edge technique as well as direct and indirect annuloplasty. In summary, patients with FMR as a result of a dilatation of the mitral valve annulus appear to be suitable for direct annuloplasty with the Cardioband® system.

Percutaneous tricuspid annuloplasty

Severe tricuspid regurgitation (TR) is a common problem, affecting approximately 1.6 million Americans, with the majority (85%) of TR being functional in nature. When left untreated, TR is associated with progressive right-sided heart failure, with a poor prognosis entailing high morbidity and mortality. Surgical repair is still the gold standard for TR, but only a small proportion of patients undergo surgical repair leaving a high clinical demand for alternatives to conventional surgery. Percutaneous repair and replacement of cardiac valves have exponentially advanced in the past decade, including transcatheter tricuspid valve repair. There are still anatomical challenges that need to be addressed when performing a percutaneous transcatheter annuloplasty compared to a surgical annuloplasty, such as approach, access, landing zone, proximal structures and visibility. Current percutaneous annuloplasty systems either obtain a direct (Cardioband) or indirect (TriCinch and Trialign) annuloplasty. Both direct and indirect percutaneous annuloplasties are modeled after surgical experiences. This review will investigate novel direct and indirect transcatheter annuloplasty devices for repair of severe tricuspid regurgitation.