Prognostic impact of leaflet-to-annulus index in patients treated with transapical off-pump echo-guided mitral valve repair with NeoChord implantation

Transcatheter treatment of the tricuspid valve: current status and perspectives

Transcatheter tricuspid valve interventions (TTVI) are emerging as alternatives to surgery in high-risk patients with isolated or concomitant tricuspid regurgitation. The development of new minimally invasive solutions potentially more adapted to this largely undertreated population of patients, has fuelled the interest for the tricuspid valve. Growing evidence and new concepts have contributed to revise obsolete and misleading perceptions around the right side of the heart. New definitions, classifications, and a better understanding of the disease pathophysiology and phenotypes, as well as their associated patient journeys have profoundly and durably changed the landscape of tricuspid disease. A number of registries and a recent randomized controlled pivotal trial provide preliminary guidance for decision-making. TTVI seem to be very safe and effective in selected patients, although clinical benefits beyond improved quality of life remain to be demonstrated. Even if more efforts are needed, increased disease awareness is gaining momentum in the community and supports the establishment of dedicated expert valve centres. This review is summarizing the achievements in the field and provides perspectives for a less invasive management of a no-more-forgotten disease.

Feasibility of concomitant exclusion of left atrial appendage during novel transapical off-pump beating heart mitral valve repair

The AtriClip device enables the safe and reproducible epicardial clipping of the left atrial appendage. Transapical off-pump beating heart mitral valve repair using NeoChord DS100 Artificial Chordae Delivery System has matured and become more standardized. We aim to evaluate the feasibility of combining NeoChord repair and left atrial appendage exclusion in a single procedure through the same minithoracotomy in patients with mitral valve prolapse and atrial fibrillation. From 2018 to 2019, seven patients with severe mitral regurgitation and atrial fibrillation underwent transesophageal echocardiography-guided transapical off-pump mitral valve repair with the novel NeoChord DS 1000 system and concomitant left atrial appendage exclusion using the AtriClip Pro II device. Both procedures were performed via left mini-thoracotomy. The AtriClip device was applied after the NeoChord repair was done. All seven patients had less than moderate mitral regurgitation after the NeoChord repair and successful left atrial appendage occlusion. There were no device or procedure-related complications. Clinical follow-up revealed significant symptomatic improvement, and no cardiovascular complications were reported. Transesophageal echocardiography at 6-12 months post-procedure showed stable left atrial appendage occlusion with no residual flow between the left atrium and the left atrial appendage and a stump of less than 5 mm. Beating heart epicardial clipping of the left atrial appendage using AtriClip concomitant with transapical mitral valve repair using Neochord DS 1000 system is a feasible and safe treatment option in mitral valve prolapse and atrial fibrillation in patients with limited indications. However, its safety needs to be confirmed in a larger series of patients.

Mitral valve leaflet stiffness predicts residual mitral regurgitation after transcatheter edge-to-edge mitral valve repair

BACKGROUND

Residual regurgitation after transcatheter edge-to-edge mitral valve repair (TMVR) is a predictor of poor prognosis in patients with functional mitral regurgitation (FMR). This study sought to identify the mitral valve (MV) parameters measured by three-dimensional transesophageal echocardiography (3D-TEE) and MV leaflet features that predict residual mitral regurgitation (MR) after TMVR in patients with FMR.

METHODS

Consecutive patients with FMR who underwent TMVR were classified into two groups based on the degree of residual MR just after TMVR: < 2+ in the optimal MR reduction group and ≥ 2+ in the suboptimal MR reduction group. The two groups were compared with respect to 3D-TEE parameters and the MV leaflet features, including the following parameters: stiffness, defined as a leaflet that remains at a fixed angle even during diastole, and thickness, measured in both clear and rough zones.

RESULTS

Thirty-four of 46 patients (74%) were classified as the optimal MR reduction group. Multivariable analysis showed that anterior mitral leaflet + posterior mitral leaflet length/anteroposterior annulus diameter (p = .044) and MV leaflet stiffness (p = .007) were independent predictors of residual MR.

CONCLUSION

MV leaflet stiffness and the ratio of MV leaflet lengths to the annulus diameter may be good predictors of residual MR after TMVR in patients with FMR.

Multimodality imaging for patient selection, procedural guidance, and follow-up of transcatheter interventions for structural heart disease: a consensus document of the EACVI Task Force on Interventional Cardiovascular Imaging: part 1: access routes, transcatheter aortic valve implantation, and transcatheter mitral valve interventions

Transcatheter therapies for the treatment of structural heart diseases (SHD) have expanded dramatically over the last years, thanks to the developments and improvements of devices and imaging techniques, along with the increasing expertise of operators. Imaging, in particular echocardiography, is pivotal during patient selection, procedural monitoring, and follow-up. The imaging assessment of patients undergoing transcatheter interventions places demands on imagers that differ from those of the routine evaluation of patients with SHD, and there is a need for specific expertise for those working in the cath lab. In the context of the current rapid developments and growing use of SHD therapies, this document intends to update the previous consensus document and address new advancements in interventional imaging for access routes and treatment of patients with aortic stenosis and regurgitation, and mitral stenosis and regurgitation.

Correlation between the Leaflet-Annulus Index and Echocardiographic Indices in Maltese Dogs with Myxomatous Mitral Valve Disease

Myxomatous mitral valve disease (MMVD) is the most common chronic heart valve disease, leading to left-sided cardiomegaly in dogs. The leaflet-annulus index (LAI) was originally used in humans as a predictor of mitral regurgitation (MR) after mitral valve repair surgery. This index represents the quantity and severity of MR since it is affected by annular dilation. Recently, LAI was adapted to veterinary medicine, and its usefulness as an indicator of annular dilation on 2D transthoracic echocardiography in MMVD dogs was suggested. For this study, 135 Maltese dogs were selected and divided into groups of control, B1, and B2, according to the American College of Veterinary Internal Medicine consensus statement. The following data were collected: radiographic indices including the vertebral heart score and vertebral left atrial size, echocardiographic indices including the left-atrium-to-aortic-root ratio (LA:Ao), left ventricular internal diameter at diastole, normalized for body weight, and anteroposterior length and LAI measured on right parasternal long-axis view. The results showed a significant difference in LAI between each group, becoming smaller as the disease progressed. Also, there was a significant correlation between LAI and each index, showing the strongest correlation with LA:Ao. LAI could be helpful as a new indicator used for the determination of severity and prognosis in Maltese dogs with MMVD.

Echocardiographic and clinical outcomes following beating heart NeoChord DS1000 mitral valve repair: a single centre case series

Background

The NeoChord DS1000 system implants artificial neochords transapically, through a left mini-thoracotomy to treat degenerative mitral valve regurgitation (MR). Performed without cardiopulmonary bypass, neochord implantation and length adjustment is guided by transesophageal echocardiography. We describe imaging and clinical outcomes for a single center case series using this innovative device platform.

Methods

In this prospective series, all study patients had degenerative MR and were considered for conventional mitral valve surgery. Moderate to high-risk candidates were screened for NeoChord DS1000 eligibility based on echocardiographic criteria. Study criteria included isolated posterior leaflet prolapse, leaflet-to-annulus index greater than 1.2, and coaptation length index greater than 5 mm. Patients with bileaflet prolapse, mitral annular calcification, and ischemic MR were excluded from our early experience.

Results

Ten patients underwent the procedure, including 6 males and 4 females, with a mean age of 76 ± 9.5 years. All patients had severe chronic MR and normal left ventricular function. One patient required conversion to an open procedure for failure to deploy neochords with the device transapically. The median number of NeoChord sets was 3 (IQR 2.3-3.8). Immediate post-procedure (POD#0) degree of MR on echocardiography ranged from mild or less, and on postoperative day 1 (POD#1) from moderate or less. Average length of coaptation was 0.85 ± 0.21 cm and average depth of coaptation was 0.72 ± 0.15 cm. At 1-month follow-up echocardiography, MR was graded from trivial to moderate and left ventricular inner diameter dimensions decreased from an average of 5.4 ± 0.4 cm to 4.6 ± 0.3 cm. None of the patients who had successful NeoChord implantation required blood products. There was 1 perioperative stroke with no residual deficits. There were no device-related complications or serious adverse events. The median length of hospital stay was 3 (IQR 2.3-10) days. 30-day and 6-weeks postoperative mortality and readmission rates were 0%.

Conclusion

We report the first Canadian case series using the NeoChord DS1000 system for off-pump, transapical, beating heart mitral valve repair, through a left mini-thoracotomy. The early surgical outcomes suggest this approach is feasible, safe, and effective in reducing MR. This novel procedure has the advantage of offering a minimally invasive, off-pump option for select patients with high surgical risk.

Outcomes of transapical mitral valve repair with neochordae implantation

OBJECTIVE

Transapical off-pump beating-heart neochord implantation (NC) has shown encouraging early results in patients with degenerative mitral regurgitation. The aim of this study was to evaluate clinical and echocardiographic 5-year outcomes of patients who underwent NC.

METHODS

All patients who underwent NC at our institution from November 2013 to March 2016 were included. Indications were severe symptomatic degenerative mitral regurgitation due to leaflet prolapse/flail. Patients were classified as having favorable anatomy (FA) and unfavorable anatomy (UA) on the basis of the extent and severity of mitral valve disease. All patients underwent clinical and echocardiographic follow-up at 1, 3, 6, and 12 months, and annually thereafter. Data were prospectively collected and retrospectively analyzed. Outcomes were on the basis of the Mitral Valve Academic Research Consortium guidelines.

RESULTS

One hundred consecutive patients were included in the analysis (FA: 81%; UA: 19%). Median age was 66 years (interquartile range, 58-76) and median European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was 1.4% (interquartile range, 0.7-2.3). Technical and procedural success were 98% and 94%, respectively. Thirty-day mortality was 2%. Device success was 94%, 92%, and 78%, at 30 days, 1-year, and 5 years, respectively. Patient success at 1 year was 92%. Median follow-up was 5.1 years. At 5 years, overall survival was 83% with no difference between FA and UA patients. Cumulative incidence of severe mitral regurgitation recurrence at 5 years was 14% (95% CI, 6.5%-22.8%) in FA patients and 63% (95% CI, 39.7%-86.2%) in UA patients, respectively (P < .001). Patients with FA compared with UA had a lower incidence of reintervention (14.7% vs 43.4%; P < .001).

CONCLUSIONS

Transapical off-pump beating heart NC might represent an acceptable option in patients with degenerative mitral valve disease and FA.

New Echocardiographic Parameters Predicting Successful Trans-Ventricular Beating-Heart Mitral Valve Repair with Neochordae at 3 Years: Monocentric Retrospective Study

The NeoChord procedure is an echo-guided trans-ventricular beating-heart mitral valve repair technique to treat degenerative mitral regurgitation (MR) due to prolapse and/or flail. The aim of this study is to analyze echocardiographic images to find pre-operative parameters to predict procedural success (≤moderate MR) at 3-year follow-up. Seventy-two consecutive patients with severe MR underwent the NeoChord procedure between 2015 and 2021. MV pre-operative morphological parameters were assessed using 3D transesophageal echocardiography with dedicated software (QLAB, Philips). Three patients died during their hospitalization. The remaining 69 patients were retrospectively analyzed. At follow-up, MR > moderate was found in 17 patients (24.6%). In the univariate analysis, end-systolic annulus area (12.5 ± 2.5 vs. 14.1 ± 2.6 cm²; p = 0.038), end-systolic annulus circumference (13.2 ± 1.2 vs. 14 ± 1.3 cm; p = 0.042), indexed left atrial volume (59 ± 17 vs. 76 ± 7 mL/m²; p = 0.041), and AF (25% vs. 53%; p = 0.042) were lower in the 52 patients with ≤ MR compared to those with > moderate MR. Annular dysfunction parameters were the best predictors of procedural success: 3D early-systolic annulus area (AUC 0.74; p = 0.004), 3D early-systolic annulus circumference (AUC 0.75; p = 0.003), and 3D annulus area fractional change (AUC 0.73; p = 0.035). Patient selection relying on 3D dynamic and static MA dimensions may improve the maintenance of procedural success at follow-up.

A journey from resect to respect to restore: aiming at optimal physiological surgical mitral valve repair

The concept of 'repairing' a degenerated mitral valve in order to restore the native competence means achieving the best physiological result coupled with the least invasive approach: this represents an interesting challenge for cardiac surgeons. The evolution of cardiac surgery through the years has involved techniques and technologies in every field of interest. From 'resect', to 'respect', to 'restore': the micro-invasive approach based on Neochord implant implies a transapical beating heart surgery which is based on the concept of implanting artificial chordae, preserving the physiological dynamics of the mitral annulus and avoiding the disadvantages of cardiopulmonary bypass and cardioplegic arrest of the heart.

Transapical mitral valve repair procedures: Primetime for microinvasive mitral valve surgery

INTRODUCTION

Nowadays micro-invasive-procedures (off-pump, beating-heart) for mitral valve repair (MVRe) are abruptly expanding with the potential to be adopted as a valuable alternative to surgery. In the present manuscript, the authors review the available technologies intended to treat mitral regurgitation (MR) through transapical approach, including annuloplasty and chordal-repair options.

ANNULOPLASTY

To date, Valcare Amend is the only transapical MV ring to have been implanted in patients. The device allows for stabilization of the annulus through a complete semirigid d-shaped ring. The first-in-human successful procedure was performed in 2016 by our Group and subsequent clinical experience included a total of 14 implanted patients. Currently, the technology is under clinical trial evaluation to validate the efficacy and safety profile of the device.

CHORDAL REPAIR

Beating-heart chordal implantation via transapical approach is a current feasible, safe and reproducible option. Neochord DS1000 is the most widely used technology in the field, with a solid procedural experience and good results in well-selected patients. Its clinical use has been validated in Europe since 2012, while it is still under clinical investigation in the United States. Harpoon MVRe system is a novel technology, recently CE-mark approved for clinical use.

DISCUSSION AND CONCLUSIONS

Transapical micro-invasive technologies are current viable therapies to treat MR in selected patients. Although there are still several limitations that preclude an extensive use of such procedures, their results are promising in well-selected patients. Embracing transcatheter MVRe therapies should guide the cardiac surgeon through the new revolution of micro-invasive MV tailored repair.

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

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

The leaflet-annulus index in canine myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common chronic heart valve disease, leading to the eccentric hypertrophy. Recently, the leaflet-annulus index (LAI), which focuses on the mitral valve apparatus, has been considered a prognostic factor for human mitral regurgitation (MR); however, it has not been reported in veterinary medicine. In the present study, we retrospectively evaluated the LAI in dogs with MMVD. Eight-three dogs with MMVD diagnosed using echocardiography were included in this study. The anteroposterior length, anterior and posterior cusp coaptation lengths, LAI, left ventricular end-diastolic internal diameter normalized to body weight (LVIDDN), and left atrium to aorta ratio (LA/Ao) were measured. A significant correlation between the LAI, LVIDDN, and LA/Ao of MR grading, and left ventricle dilation was observed. In conclusion, LAI could help determine annular widening, suggesting the decision of an appropriate for SVR in clinical settings.

Actual perspective on off-pump transapical artificial chord implantation

Mitral valve repair (MVR) is undisputedly associated with better clinical and functional outcomes than any other type of valve substitute. Conventional mitral valve surgery in dedicated high-volume centers can assure excellent results in terms of mortality and freedom from mitral regurgitation (MR) recurrence but requires cardiopulmonary bypass (CPB) and cardioplegic heart arrest. Trying to replicate the percentage of success of surgical MVR is the aim of all new transcatheter mitral dedicated devices. In particular, transapical beating-heart mitral valve repair by artificial chordae implantation with transesophageal echocardiography guidance is an expanding field. The safety and feasibility of the procedure have already been largely demonstrated with Neochord and more recently with Harpoon systems. Wang et al. present the outcomes of the first-in-human experience using a novel artificial chordae implantation device, the Mitralstitch system. Despite a quite small cohort of only 10 patients treated, 1-year results are satisfying and comparable with the early experience with former devices (4 patients with moderate or more MR recurrence). The comparison with surgical MVR is still unfavorable and requires further studies and significant procedure improvement. However, the device permits the treatment of anterior and posterior leaflets prolapse and performs quite easily edge-to-edge reparation. It will be interesting to evaluate longer follow-up in larger cohorts of patients as well as the possibility to shift to the transfemoral approach.

Feasibility of percutaneous coronary intervention before mitral NeoChord implantation: Single-center early results

BACKGROUND AND AIM OF THE STUDY

Micro-invasive cardiac surgery identifies procedures performed off-pump, on beating heart. Aim of this single-center retrospective study was to assess early outcomes of a totally micro-invasive strategy (percutaneous coronary intervention-PCI-followed by transapical off-pump NeoChord mitral repair) in patients with concomitant coronary artery disease (CAD) and degenerative mitral regurgitation (MR).

METHODS

We analyzed early and 1-year follow-up data of patients who underwent a NeoChord procedure between November 2013 and May 2020, and preceded by PCI. Outcomes were defined according to Mitral Valve Academic Research Consortium (MVARC) definitions.

RESULTS

Among 220 patients who underwent NeoChord repair in the study period, 17 (7.7%) underwent PCI previously. CAD was an accidental finding during preoperative mitral evaluation in nine patients (52.9%; Group 1; with PCI occurring 2 months before NeoChord, interquartile range [IQR] = 1.0-2.7), while it was part of the past medical history in the remaining eight patients (47.1%; Group 2; with PCI occurring 30 months before NeoChord, IQR = 24.5-64.0). Twelve patients (70.6%) presented single-vessel disease, two patients (11.8%) triple-vessel disease. No surgical revisions for bleeding were required after NeoChord. At 1-year follow-up (n = 16), all patients were alive and did not experience major adverse events except for one reoperation due to late NeoChord failure. None required additional PCI.

CONCLUSION

In our experience, PCI before NeoChord seems safe and effective, and performing PCI before NeoChord might not affect outcomes. A totally micro-invasive strategy in selected patients suffering from MR and CAD should be considered as a reasonable alternative to conventional surgery.

Transapical off-pump mitral valve repair following prior mitral valve surgery: A case report

RATIONALE

Redo surgeries after mitral valve repair are technically demanding. Procedures applying the NeoChord device (NeoChord Inc, St. Louis Park, MN) have proven to be safe and feasible in selected patients requiring mitral valve repair due to a leaflet prolapse or flail. However, its use for redo procedures after conventional surgical repair has not been well established yet.

PATIENT CONCERNS

We report the case of a 57-year-old man who presented with dyspnea upon exertion. The patient had undergone a minimally invasive surgical mitral valve repair because of a flail leaflet of the segments segment 2 of the posterior mitral valve leaflet (P2)/segment 3 of the posterior mitral valve leaflet (P3) 4 years before.

DIAGNOSES

Transesophageal echocardiography identified a relapse of severe mitral valve regurgitation. The recurring regurgitant jet was caused by a flail leaflet due to newly ruptured native chords.

INTERVENTIONS

After discussion in an interdisciplinary heart team, we performed a minimally invasive off-pump redo procedure applying the NeoChord device under three-dimensional transesophageal echocardiographic guidance.

OUTCOMES

The echocardiographic result with only trivial residual mitral regurgitation as well as the further clinical course of the patient were favorable.

LESSONS

As redo surgery after minimally invasive mitral valve repair is challenging, the NeoChord device represents a novel treatment option that does not require cardiopulmonary bypass.

Review of transapical off-pump mitral valve intervention with NeoChord implantation

PURPOSE OF REVIEW

Mitral valve repair surgery has recently shifted from resection-based techniques to leaflet sparing approaches using synthetic neochordae. This has facilitated the growth of a new strategy of transapical off-pump mitral valve intervention with neochord implantation.

RECENT FINDINGS

Minimally invasive approaches for mitral valve repair with robotic or video-assisted mini-right anterolateral thoracotomy have been developed to mitigate the morbidity associated with conventional median sternotomy. Recently, an alternative, less invasive surgical strategy has emerged. This transapical off-pump technique employs the NeoChord DS1000 (NeoChord, Inc., Minneapolis, MN, USA) system to achieve repair with neochordae via a left minithoracotomy incision. With appropriate patient selection, advanced cardiac imaging, and training in device deployment are important for procedural success.

SUMMARY

Early results suggest that transapical off-pump mitral valve intervention with NeoChord implantation is a safe procedure with favorable outcomes for select patients with degenerative mitral regurgitation. Continued experience and clinical trials will assess the potential of this minimally invasive strategy, but this technique is likely to become part of the surgical repertoire for managing chronic degenerative mitral valve disease.

Transcatheter Repair of the Mitral Valve: Relevant Pathophysiology, Investigation, and Management

Mitral regurgitation (MR) is a common condition causing significant morbidity and mortality in the Western world. Although surgical therapy has developed over 5 decades to provide solutions, only a minority of patients undergo surgery. The last decade has seen the emergence and application of multiple transcatheter techniques in attempts to address this undertreated population with the large clinical experience of MitraClip providing the most insight. Clear understanding of the pathophysiology of different MR types as well as the role of particularly secondary MR on patient's clinical syndrome allow for better prediction as to which patient subgroups will benefit from different repair techniques or intervention at all. Most of the techniques are based on surgical technique and are applied as single-device/technique solutions, whether leaflet, chordal, or annular solutions, but with broadening experience, combination therapies are likely to find a place in creating a more complete and surgical-like solution.

Transapical off-pump mitral valve repair with NeoChord implantation: A systematic review

INTRODUCTION

Mitral valve repair (MVr) is the gold standard for the treatment of degenerative mitral valve regurgitation (MR). The recently introduced NeoChord DS1000 has gained increasing recognition as a feasible, potentially safe, and effective procedure with minor complications and promising outcomes. This study aims to conduct a systematic review of the published literature that discusses the technical feasibility and outcome of transapical off-pump MVr with NeoChord DS1000 device implantation in the treatment of degenerative MR.

METHODS

This review was performed according to the PRISMA statement. Databases searched in this review included Pubmed, Web of Science, Scopus, and Cochrane databases for systematic reviews. All English articles on humans reporting isolated MVr using NeoChord DS1000 device were included provided that basic preoperative data, operative specifications, and postoperative mortality and morbidity were reported.

RESULTS

This review included six studies comprised 249 patients who had NeoChord mitral procedure. Almost all patients included had severe MR (243/249, 97.6%). Operative success was achieved in 241 out of the 249 patients (96.8%). No intraoperative mortality was reported. Intraoperative arrhythmia was reported in six patients (2.4%) and significant bleeding was reported in eight patients (3.2%).

CONCLUSION

Awaiting more evidence, NeoChord mitral procedure appears to be a promising procedure that can be considered in selected cases.

Quadrangular resection versus chordal replacement for degenerative posterior mitral leaflet prolapse

Background

The aims of the present study was to compare midterm results of quadrangular leaflet resection versus chordal replacement for the repair of degenerative posterior mitral leaflet (PML) prolapse, and to explore the risk factors for recurrent severe mitral regurgitation (MR).

Methods

From January 2012 to December 2018, 1,423 consecutive patients underwent mitral valve (MV) repair. A total of 317 had degenerative PML prolapse and constituted the study population. Of these, 74 (23.3%) underwent quadrangular leaflet resection, and 243 (76.7%) underwent chordal replacement. Outcomes were compared by using unadjusted data and propensity score-matched analyses.

Results

Patients with multiple leaflet prolapse were more likely to undergo chordal replacement (18.4% vs. 41.9%, P<0.001), and performed as a minimally invasive approach (47.3% vs. 61.7%, P=0.027). Of the entire cohort, 1 death (0.3%) occurred due to intraoperative aortic dissection, and 1 patient who had undergone chordal replacement required reoperation before discharge for posterior leaflet tearing. There was no significant difference in the probability of freedom from recurrent severe MR at 82 months between the resection and neochordae groups in both the pre-matched (95.6% vs. 88.8%, P=0.105) and matched (95.2% vs. 88.5%, P=0.170) cohorts, which was consistent across all of the examined subgroups (P>0.05). Multivariate Cox regression indicated that dilated left ventricular end-systolic diameter (LVESD) was an independent risk factor for recurrent severe MR [<40 vs. >40 mm, hazards ratio (HR): 3.17, 95% confidence interval (CI): 1.20–8.39, P=0.020]; however, surgical technique was not (resection vs. neochordae, HR: 0.31, 95% CI: 0.07–1.37, P=0.122).

Conclusions

Chordal replacement for the repair of degenerative posterior MV prolapse yields similar satisfactory outcomes when compared with quadrangular resection, and is promising in minimally invasive cardiac surgery for various lesions. However, it is also associated with more recurrent severe MR, albeit non-significant, for which patients with dilated LVESD are at high risk.

Transapical off-pump echo-guided mitral valve repair with neochordae implantation mid-term outcomes

BACKGROUND

The NeoChord echo-guided transapical beating heart repair is a promising early-stage minimally invasive surgical procedure for degenerative mitral valve (MV) regurgitation (DMR) correction. The technique has been improved since its inception following procedure standardization, patient selection optimization, and learning curve stabilization. We hereby present the mid-term clinical results through three years of our large single center experience.

METHODS

All consecutive patients with severe symptomatic DMR due to prolapse or flail of one or both mitral leaflets that underwent the NeoChord procedure between November 2013 and June 2019 were included. Patients were categorized according to MV anatomy; Type A isolated central posterior leaflet prolapse and/or flail, Type B posterior multi-segment prolapse and/or flail, Type C anterior and/or bi-leaflet prolapse or flail, Type D paracommissural prolapse and/or flail and/or significant leaflet and/or annular calcifications. Patients underwent clinical and echocardiographic follow-up at one, three, six, twelve months and yearly thereafter. Clinical outcomes and the composite primary endpoint (patient success) were defined according to Mitral Valve Academic Research Consortium (MVARC) criteria. Mitral regurgitation (MR) severity was graded as absent, mild, moderate and severe according to American Society of Echocardiography (ASE) and European Society of Cardiology (ESC) guidelines.

RESULTS

Two hundred and three patients were included; median follow-up was 24 months [interquartile range (IQR), 9-36]. Median age was 64 years (IQR, 54-74 years), median Society of Thoracic Surgeons (STS) Predicted Risk of Mortality (PROM) was 0.60% (IQR, 0.32-1.44%). There were 106 Type A patients (52.2%), 68 Type B (33.5%), 16 Type C (7.9%), and 13 Type D (6.4%). Kaplan-Meier estimate of survival was 99.0%±0.7% at one and two years and 94.0%±2.9% at three years. At one-year follow-up patient success was 91.2%±2.0% and 111 patients (74%) presented a residual MR mild or less (1+). At three-year follow-up patient success was 81.2%±3.8% and 32 patients (64%) had a residual MR mild or less (1+). Patient success was significantly different according to anatomical type (P=0.001). Echocardiographic analysis showed a significant acute left ventricle and left atrial reverse remodeling that was maintained up to three years.

CONCLUSIONS

The NeoChord echo-guided transapical beating heart repair procedure demonstrated good clinical outcomes and echocardiographic results up to three-year follow-up.

Transseptal chordal replacement: early experience

Chordal replacement is a fundamental technique used in the surgical repair of primary mitral regurgitation, and can be an effective means of preserving the native valve without leaflet resection. Surgical chordal replacement can be challenging since it is performed on an open, non-beating heart, and choosing the correct chord length to restore the zone of coaptation requires both intuition and skill. Developing transcatheter, transfemoral, and transseptal approaches to mitral valve chordal replacement presents the opportunity for safer and potentially earlier treatment of patients with primary mitral regurgitation. In particular, transcatheter methods will allow adjustment of chordal length and position real-time on a beating heart under echocardiographic guidance. In this manuscript, we review the current transcatheter transseptal technologies in development and discuss the various issues related to device design, efficacy, durability, and clinical trial design.

Combining echocardiographic and anatomic variables to predict outcomes of mitral valve repair with the NeoChord procedure

BACKGROUND

Trans-apical, echo-guided NeoChord mitral valve (MV) repair is an innovative procedure to treat degenerative mitral regurgitation (MR) without concomitant annuloplasty. Recently, leaflet-to-annulus index (LAI) has been identified as a positive prognostic predictor of outcomes at 1-year follow up. The aim of this study is to develop a pre-operative predictor tool to assess probability of success with NeoChord procedure utilizing multi-factor echocardiographic and anatomic variables.

METHODS

We included ninety-one consecutive patients with prolapse/flail of the posterior mitral leaflet, who subsequently underwent NeoChord MV repair between November 2013 and October 2016. All patients completed post-operative echocardiographic follow-up assessments for up to 2 years. A random forest regression algorithm identified and ranked the most relevant predictors of moderate-severe MR. A multi-variable Cox regression model was performed at follow-up intervals, to assess variables associated with residual MR that was classified as mild or less. Bootstrapping re-samples were used to validate an estimated survival model. Predictive accuracy was assessed using a discrimination index that corrected for over-optimism.

RESULTS

We developed a nomogram which used the results of a multi-variable model to predict the probability of mild or less residual MR at follow-up periods (discharge, 1, 3, 6 months, 1 and 2 years). Identified predictors included LAI, systolic pulmonary artery pressure, indexed left ventricle end-systolic volume (iLVESV), prolapse/flail width (FW), systolic antero-posterior (AP) annulus diameter, systolic latero-lateral (LL) annulus diameter and presence of calcification.

CONCLUSIONS

A NeoChord MV repair prediction tool would be helpful in clinical decision-making and in the identification of patients who may benefit from a ringless mitral valve repair using the NeoChord procedure.

Insufficient Mitral Leaflet Remodeling in Relation to Annular Dilation and Risk of Residual Mitral Regurgitation After MitraClip Implantation

OBJECTIVES

The purpose of this study was to determine whether the mitral valve (MV) total leaflet area (TLA)-to-mitral annular area (MAA) (TLA/MAA) ratio measured using 3-dimensional (3D) transesophageal echocardiography (TEE) was associated with residual mitral regurgitation (MR) after MitraClip implantation in patients with secondary MR.

BACKGROUND

The factors influencing the results of MitraClip implantation for secondary MR are controversial. This study hypothesized that insufficient remodeling of the mitral leaflets relative to the annular dilation may be associated with significant MR after MitraClip implantation.

METHODS

This study included patients with secondary MR treated with MitraClips. Using 3D TEE dataset, the TLA in diastole and MAA in systole were measured with dedicated software.

RESULTS

In a total cohort of 119 patients (mean age 74 ± 9 years; 61% male), significant residual MR (≥2+) was present in 43 patients (36%). In patients with significant residual MR, MAA was greater than in patients without residual MR (10.7 ± 2.4 cm² vs. 9.0 ± 2.1 cm²; p < 0.001) whereas no significant difference was observed in TLA (12.2 ± 2.6 cm² vs. 12.0 ± 2.9 cm²; p = 0.836). TLA/MAA ratio was lower in patients with significant residual MR as compared to their counterparts (1.14 ± 0.15 vs. 1.34 ± 0.16; p < 0.001), suggesting insufficient leaflet remodeling relative to annular dilation. On receiver-operating characteristic curve analysis, the TLA/MAA ratio had better discriminative power to identify patients who will have significant residual MR compared to MAA alone (area under the curve [AUC]: 0.830 vs. 0.723; p = 0.049).

CONCLUSIONS

In patients with secondary MR, insufficient mitral leaflet remodeling relative to the annulus dilation, as reflected by a lower TLA/MAA ratio, is associated with significant residual MR after MitraClip implantation.

Mechanisms of recurrent regurgitation after transapical off-pump mitral valve repair with neochord implantation†

OBJECTIVES

The aim of this study was to describe possible mechanisms of recurrent mitral regurgitation (MR) in patients who have been treated with the NeoChord procedure.

METHODS

Patients presenting with recurrent severe or moderate MR were categorized as Not Expected Surgical-Like Result (NESLR)-Redo and NESLR-MR2 [NESLR reintervention or moderate MR (2+), respectively]. NESLR patients were stratified by onset (intraoperative, perioperative 24 h-30 days, or early 30 days to follow-up), by MR jet direction (central or eccentric) and by jet orientation (anterior or posterior). Specific mechanisms of NESLR were analysed.

RESULTS

Fifty-two patients were identified with 13 (25%) categorized as NESLR-Redo, and 39 (75%) as NESLR-MR2. NESLR-Redo patient stratification included: intraoperative = 2 patients (1.2%), both eccentric anteriorly directed jets; perioperative = 7 patients (4.2%), all eccentric with 3 anteriorly and 4 posteriorly directed jets; and early = 4 patients (2.4%), 1 central, 3 eccentric, 2 posteriorly and 1 anteriorly directed jets. NESLR-MR2 patient stratification included: perioperative = 2 patients (5.1%), both eccentric, 1 anteriorly and 1 posteriorly directed jets; and early = 37 patients (94.9%), 4 central, 33 eccentric, 22 anteriorly and 11 posteriorly directed jets. Possible mechanisms of recurrent MR were identified as: patient selection (17.3%), technical issues (28.8%), progression of baseline disease (15.4%), left ventricle reverse remodelling (1.9%), excessive over-tensioning (35.8%) and PML curling (30.8%).

CONCLUSIONS

The mechanisms of recurrent MR after the NeoChord procedure can be determined. Understanding recurrent MR mechanisms has led to improvements in procedural standardization and ad hoc prevention strategies that have been widely adopted since our initial clinical experience.

Combined off-pump mitral repair and thoracoscopic maze surgery

A 67-year-old man with severe mitral regurgitation and paroxysmal atrial fibrillation was admitted to our institution for surgical repair. The procedure was carried out off-pump. We first performed a totally thoracoscopic maze box lesion set with epicardial transmural radiofrequency, and clipped the left atrial appendage. The mitral valve prolapse was repaired by implanting three transapical neochordae. Six months later, the patient was in sinus rhythm with minimal residual mitral regurgitation on echocardiography. This novel approach is less invasive than the standard surgical correction and should ensure a faster recovery with similar safety and efficacy in selected cases.

Prediction for residual regurgitation after MitraClip for functional mitral regurgitation using leaflet coaptation index

BACKGROUND

Given the recent growth in the number of MitraClip procedures in patients with functional mitral regurgitation (MR), there is interest in an echocardiographic index to predict technical success before intervention. We investigated the utility of a novel leaflet coaptation index (LCI) to predict outcomes after MitraClip in functional MR patients.

METHODS

Forty consecutive patients with functional MR who underwent MitraClip were included. The LCI was defined as the coapted leaflet length divided by the anteroposterior diameter of the mitral annulus. The coapted leaflet length was calculated by separately tracing the total length of the mitral valve leaflets at early and end systole on transesophageal echocardiography. The primary endpoint was defined as residual MR ≥ moderate after MitraClip.

RESULTS

The LCI was significantly associated with residual MR ≥ moderate (odds ratio, 0.827; 95% confidence interval, 0.696-0.982; p = .030) with the cut-off LCI value of 0.14 (sensitivity 70.4%, specificity 69.2%, c-statistic 0.815; p = .001).

CONCLUSION

This novel index may be a useful adjunct that can be incorporated into the armamentarium of contemporary clinical performance risk prediction tools for MitraClip success.

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

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

Emerging Technologies for Percutaneous Mitral Valve Repair

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

Use of a photo-realism 3D rendering technique to enhance echocardiographic visualization of the anatomical details during beating-heart mitral valve repair

The NeoChord procedure is an innovative microinvasive, transventricular, beating-heart chordal replacement technique for patients with severe degenerative mitral valve regurgitation resulting from prolapsed or flail leaflets. Use of three-dimensional (3D) transoesophageal echocardiographic imaging is crucial to the physician operator for device navigation during the procedure and to assess the functional results of the repair at the end of the procedure. Photo-realistic, 3D rendering techniques have been recently developed for medical use. Philips TrueVue (Philips Healthcare, Eindhoven, NL) is a photo-realism technique that employs the use of a virtual light source that simulates the interaction of light on 3-dimensional surfaces. Use of photo-realism techniques, in conjunction with 3D echocardiography, improves the visualization of morphological characteristics of the mitral valve before, during, and after beating-heart mitral valve repair procedures.

Transcatheter Mitral Valve Chordal Repair: Current Indications and Future Perspectives

Transcatheter Mitral Valve Repair (TMVRe) technologies constitute a rapidly expanding field, and have the potential of being adopted as a valuable alternative to surgery in selected patients. TMVRe devices can be distinguished depending on the targeted part of the Mitral Valve (MV) apparatus. Standard classification includes leaflet repair, direct/indirect annuloplasty, chordal repair, and ventricular/chamber remodeling devices. We present the current device situation on chordal repair technologies. Nowadays, transapical off-pump beating heart chordal implantation procedure has become a safe and reproducible option for Degenerative Mitral Regurgitation (DMR). Besides the truly minimally-invasiveness of the procedure, another unique advantage offered by a beating-heart chordal implantation is the real-time assessment of chordal length adjustment during heart cycle with a normally filled left ventricle. Currently, one system is commercially available in Europe, the NeoChord DS 1000 (NeoChord, Inc., St. Louis Park, MN) and the Harpoon TDS-5 (Edwards Lifesciences, Irvine, CA) should become available soon. There is also a diffuse and strong interest to move from a transapical procedure toward a fully transcatheter (transfemoral and transeptal) procedure as shown by the increased number of preclinical programs under development. Interestingly, to achieve outcomes that equate to those of open surgery in DMR, transcatheter therapies will need to follow rigid indications due to strict patient selection criteria for each device, or adopt multiple techniques in a single repair procedure for complex MV disease. Continuous analysis of current clinical results together with future dedicated trial will be of extreme importance to foster the new and upcoming field of transcatheter MV therapy technology development.

Transcatheter mitral valve chord repair

The field of mitral valve disease diagnosis and management is rapidly evolving. New understanding of pathophysiology and improvements in the adoption of sophisticated multimodality imaging modalities have led to early diagnosis and to more complex treatment. The most common cause of mitral regurgitation (MR) in the western world is in the primary alteration of the valve, which leads to degenerative leaflet prolapse due to chordal elongation or rupture and annular dilatation. Untreated, significant MR has a negative impact prognosis, leading to reduction of survival. In the setting of degenerative MR, surgical repair currently represents the standard of care. Treatment of asymptomatic patients with severe MR in the Valve Center of Excellence, in which successful repair reaches more than 95% and surgical mortality less than 1%, symbolizes the direction for the next years. Transcatheter mitral valve repair with different devices, more recently the chordal replacement ones, is providing good outcomes and became a therapeutic option in high-risk patients with degenerative MR. In the future, more advances are expected from further development of interventional techniques, careful evaluation and better patient selection. This review will focus on long-term surgical outcomes of mitral valve repair with artificial chordae and on the emerging transcatheter chordal repair devices as therapeutic options for degenerative MR patients.

Transapical NeoChord mitral valve repair

Transapical off-pump mitral valve repair (MVr) with NeoChord implantation has become widely applied in Europe for patients presenting with severe mitral regurgitation due to leaflet prolapse or flail. The procedure is performed under real-time 2D- and 3D-transesophageal echocardiography (TEE) for both implantation and neochordae tension adjustment allowing real-time monitoring of hemodynamic recovery. Preoperative anatomic and echocardiographic selection criteria, procedure refinement, as well as innovative ex-vivo surgical simulator training have been developed and strategically employed in the past few years, to generate a robust precision-based procedural framework with significantly enhanced operator use, patient safety and clinical outcomes. The procedure has evolved into a reproducibly successful and safe approach, which complements existing surgical treatment strategies available to eligible patients with chronic severe degenerative mitral regurgitation.