Transcatheter Mitral Valve Replacement in Patients With Previous Aortic Valve Replacement

TMVR after TA-TAVR: a re-redo surgery-case report

Introduction

Transcatheter mitral valve replacement (TMVR) is a valuable treatment option in patients with severe mitral regurgitation. Prior transapical transcatheter aortic valve replacement (TA-TAVR) may complicate the procedure and is therefore considered a relative contraindication. In this case report, the authors describe the successful TMVR as a tertiary cardiac surgery and transapical redo procedure.

Case Summary

An 83-year-old male patient, suffering from dyspnoea and angina, was diagnosed with severe mitral valve regurgitation (MR). He had already undergone cardiac surgery in the form of coronary artery bypass grafting at the age of 64 and TA-TAVR at 79 years. After a failed attempt at mitral valve transcatheter edge-to-edge repair, he opted for TMVR. Pre-TMVR computed tomography simulation was used to analyse possible interactions between the prostheses and to predict the neo-left ventricular outflow tract (neo-LVOT). The operation was carried out without complications. There was no bleeding and the LV function remained unchanged. On MRI, the valves were perfectly aligned without any signs of paravalvular leakage or LVOT obstruction. The patient was discharged seven days postoperatively. At the one-year follow up, there was no need for rehospitalisation and the patient had clinically improved (from NYHA IV to II). Echocardiography demonstrated a mean transvalvular gradient of under 5 mmHg and no residual MR.

Conclusion

A redo transapical access for TMVR as a tertiary cardiac operation can be easily performed. Pre-operative CT suggested good alignment of the aortic and mitral valved stent which was confirmed postoperatively.

Combined Significant Aortic Stenosis and Mitral Regurgitation: Challenges in Timing and Type of Intervention

In this narrative review, we aim to summarize the literature surrounding the assessment and management of the common, yet understudied combination of aortic stenosis (AS) and mitral regurgitation (MR), the components of which are complexly inter-related and interdependent from diagnostic, prognostic, and therapeutic perspectives. The hemodynamic interdependency of AS and MR confounds the assessment of the severity of each valve disease, thus underscoring the importance of a multimodal approach integrating valvular and extravalvular indicators of severity. A large body of literature suggests that baseline MR is associated with reduced survival post aortic valve (AV) intervention and that regression of MR post-AV intervention confers a mortality benefit. Functional MR is more likely to regress after AV intervention than primary MR. The respective natural courses of the 2 valve diseases are not synchronized; therefore, significant AS and MR at or above the respective threshold for intervention might not coincide. Surgery is primarily a 1-stop-shop procedure because of a considerable perioperative risk of repeat interventions, whereas transcatheter treatment modalities allow for a more tailored timing of intervention with reassessment of concomitant MR after AV replacement and a potential staged intervention in the absence of MR regression. In summary, AS and MR, when combined, are interlaced into a complex hemodynamic, diagnostic, and prognostic synergy, with important therapeutic implications. Contemporary approaches should consider stepwise intervention by exploiting the advantage of transcatheter options. However, evidence is needed to demonstrate the efficacy of different timing and therapeutic options.

Clinical characteristics and outcomes of patients screened for but DEemed CLInically Not suitablE for Transcatheter Mitral Valve Replacement

BACKGROUND

Transcatheter therapies are a recognized alternative intervention in patients with severe mitral regurgitation who are at high surgical risk. The purpose of this study was to characterize patients screened for transcatheter mitral valve replacement (TMVR), establish the clinical and anatomical reasons for unsuitability, and determine clinical course and early outcomes.

METHODS

International multicenter registry was conducted of consecutive patients screened for TMVR at 12 centers in Europe, the United States and Canada between April 2015 and September 2018. Patient-level retrospective data were collected for all patients screened.

RESULTS

From a total of 294 patients, 87 (30%) patients were suitable for and underwent TMVR while 207 (70%) patients were unsuitable for TMVR. There was no difference in STS predicted risk of mortality (6.3±4.3% vs 6.7±6.1%, p=0.52) for mitral valve replacement between the groups. The most common reasons for TMVR unsuitability were mitral annular size outside therapeutic range (28%) and small predicted neo-LVOT (25%). Pre-procedural multidetector computed tomographic demonstrated that patients unsuitable for TMVR had smaller predicted neo-left ventricular outflow tract (LVOT) area (318±192mm² vs 495±202mm², p=0.04). At 30-days, there was no difference in rates of rehospitalization (8% vs 8%, p=0.21), stroke (1% vs 2%, p=0.42), or mortality (4% vs 10%, p=0.10), unadjusted for procedural risk, between unsuitable for TMVR and TMVR groups, respectively.

CONCLUSIONS

Two-thirds of patient's failed screening as anatomically unsuitable for TMVR. The findings of this study have important clinical implications, highlighting an unmet clinical need and provide a target for design innovation in future iterations of TMVR devices.

Transcatheter mitral valve implantation in the ongoing structural heart revolution

Transcatheter mitral valve implantation (TMVI) has emerged as a less invasive approach potentially surmounting some of the current hurdles associated with transcatheter edge-to-edge repair and high-risk mitral valve surgery. In this review, we aimed to outline the main scenarios in the TMVI field, highlight current and upcoming devices, and describe challenges and clinical results. Finally, we briefly discuss the future perspectives for this emerging field and how TMVI might further advance the field of transcatheter treatments of mitral valve disease.

Design Variation, Implantation, and Outcome of Transcatheter Mitral Valve Prosthesis: A Comprehensive Review

The transcatheter mitral valve prosthesis is ideally suited for patients with inoperable mitral etiology. The transcatheter mitral valve implantation (TMVI) procedure has closely followed the evolution of transcatheter aortic procedures. There are considerable design variations amongst the limited TMVI prostheses currently available, and the implantation profiles of the devices are notably different. This comprehensive review will provide an overview of the current clinically tried TMVI devices with a focused outcome analysis. In addition, we have discussed the various design characteristics of TMVI and its associated failure mode, implantation technology, delivery methods, first-in-man trials, and pivotal trial summary for the synthesis of recent evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021255241, identifier: CRD42021255241.

Mixed-Valve Disease: Management of Patients with Aortic Stenosis and Mitral Regurgitation: Thresholds for Surgery Versus Percutaneous Therapies

Significant mitral regurgitation (MR), frequently seen in the presence of severe aortic stenosis (AS), results in an association that negatively affects prognosis and imposes particular challenges for both the assessment of the severity of valvular lesions and decisions regarding treatment allocation. This article reviews the available literature with regards to the assessment of MR and AS in the presence of both; surgical management and results in patients with concomitant AS and MR; the effect of MR on outcomes in patients undergoing transcatheter aortic valve replacement; the effect of transcatheter aortic valve replacement on MR severity; and percutaneous treatment for MR after transcatheter aortic valve implantation. The authors aim to provide assistance in the decision-making process to treat patients with either a higher-risk double-valve procedure or a simpler, but perhaps incomplete, single-valve option.

Transcatheter mitral valve thrombosis: A case report and literature review

Transcatheter mitral valve replacement (TMVR) is an exciting alternative therapy for complex patients with mitral valve disease. Experience with TMVR is new and there is a lot yet to discover about their durability, long-term outcomes, and complications including mitral transcatheter heart valve (THV) thrombosis. Many factors have been speculated to increased risk of THV thrombosis. Here, we report a case of a 72-year-old woman who developed mitral THV thrombosis after undergoing TMVR for severe mitral regurgitation with mitral annular calcification. We reviewed 42 TMVR papers with 1,484 patients, including 60 with mitral THV thrombosis. We discussed the most common strategies used for mitral THV thromboprophylaxis and treatment.

Atrial and ventricular flows across a transcatheter mitral valve

 

OBJECTIVES

The objective of this study was to evaluate the haemodynamic performance of transcatheter mitral valve replacement (TMVR) Implant with a focus on turbulence and washout adjacent to the ventricular surface of the leaflets. TMVR holds the promise of treating a large spectrum of mitral valve diseases. However, the haemodynamic performance and flow dynamics of such replacements are not fully understood.

METHODS

A tri-leaflet biopsrosthetic TMVR represented by Caisson implant of size 36A was implanted in the mitral position of a left heart simulator pulse duplicating system under physiological conditions. The 36A implant covers an anterior-posterior range of 26-32 mm and a commissure-to-commissure range of 30-36 mm. Transmitral pressure gradient, effective orifice area and regurgitant fraction were calculated. Particle image velocimetry was performed to evaluate turbulence in 2 perpendicular planes (Reynolds and viscous shear stresses, respectively). Additionally, dye experiments were performed to visualize washout.

RESULTS

Transmitral pressure gradient was 1.29 ± 0.27 mmHg and effective orifice area was 2.96 ± 0.28 cm2. Regurgitant fraction was 14.13 ± 0.08%. Total washout was 4.27 cardiac cycles. Largest viscous shear stress reaches 3.7 Pa and 2.4 Pa in ventricle and atrium, respectively. Reynolds shear stress in the atrial side was <10 Pa. In the ventricular side, the largest Reynolds shear stress reached ∼35 Pa.

CONCLUSIONS

TMVR leads to favourable haemodynamics with low degree of turbulence combined with fast washout around the leaflets indicating promising potential for freedom from blood damage potential and thrombosis corroborated by initial clinical studies as part of the valves's Early Feasibility Study.

Early results of a real-world series with two transapical transcatheter mitral valve replacement devices

Aims

Transcatheter mitral valve replacement (TMVR) with dedicated devices promises to fill the treatment gap between open-heart surgery and edge-to-edge repair for patients with severe mitral regurgitation (MR). We herein present a single-centre experience of a TMVR series with two transapical devices.

Methods and results

A total of 11 patients were treated with the Tendyne™ (N = 7) or the Tiara™ TMVR systems (N = 4) from 2016 to 2020 either as compassionate-use procedures or as commercial implants. Clinical and echocardiographic data were collected at baseline, discharge and follow-up and are presented in accordance with the Mitral Valve Academic Research Consortium (MVARC) definitions.

The study cohort [age 77 years (73, 84); 27.3% male] presented with primary (N = 4), secondary (N = 5) or mixed (N = 2) MR etiology. Patients were symptomatic (all NYHA III/IV) and at high surgical risk [logEuroSCORE II 8.1% (4.0, 17.4)]. Rates of impaired RV function (72.7%), severe pulmonary hypertension (27.3%), moderate or severe tricuspid regurgitation (63.6%) and prior aortic valve replacement (63.6%) were high. Severe mitral annulus calcification was present in two patients. Technical success was achieved in all patients. In 90.9% (N = 10) MR was completely eliminated (i.e. no or trace MR). Procedural and 30-day mortality were 0.0%. At follow-up NYHA class was I/II in the majority of patients. Overall mortality after 3 and 6 months was 10.0% and 22.2%.

Conclusions

TMVR was performed successfully in these selected patients with complete elimination of MR in the majority of patients. Short-term mortality was low and most patients experienced persisting functional improvement.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01757-z) contains supplementary material, which is available to authorized users.

Heart Valves Cross-Linked with Erythrocyte Membrane Drug-Loaded Nanoparticles as a Biomimetic Strategy for Anti-coagulation, Anti-inflammation, Anti-calcification, and Endothelialization

In recent years, valvular heart disease has become a serious disease threatening human life and is a major cause of death worldwide. However, the glutaraldehyde (GLU)-treated biological heart valves (BHVs) fail to meet all requirements of clinical application due to disadvantages such as valve thrombus, cytotoxicity, endothelialization difficulty, immune response, and calcification. Encouragingly, there are a large number of carboxyls as well as a few amino groups on the surface of GLU-treated BHVs that can be modified to enhance biocompatibility. Inspired by natural biological systems, we report a novel approach in which the heart valve was cross-linked with erythrocyte membrane biomimetic drug-loaded nanoparticles. Such modified heart valves not only preserved the structural integrity, stability, and mechanical properties of the GLU-treated BHVs but also greatly improved anti-coagulation, anti-inflammation, anti-calcification, and endothelialization. The in vitro results demonstrated that the modified heart valves had long-term anti-coagulation properties and enhanced endothelialization processes. The modified heart valves also showed good biocompatibility, including blood and cell biocompatibility. Most importantly, the modified heart valves reduced the TNF-α levels and increased IL-10 compared to GLU-treated BHVs. In vivo animal experiments also confirmed that the modified heart valves had an ultrastrong resistance to calcification after implantation in rats for 120 days. The mechanism of anti-calcification in vivo was mainly due to the controlled release of anti-inflammatory drugs that reduced the inflammatory response after valve implantation. In summary, this therapeutic approach based on BHVs cross-linking with erythrocyte membrane biomimetic nanoparticles sparks a novel design for valvular heart disease therapy.

Self-expanding apical closure device for full-percutaneous closed-chest transapical valve procedures with large-sized introducer sheaths: first study in an animal model

OBJECTIVES

Available apical occluders do not fulfil requirements for full-percutaneous transapical valve procedures with large-sized introducer sheaths. A self-expanding closure device designed for closed-chest transapical valve procedures was tested in an animal model to verify safety, efficacy and thrombogenicity.

METHODS

Large-sized 21-Fr introducer sheaths (Certitude™ system for Sapien™ valves) were percutaneously placed in the ventricles of nine 3-month old minipigs. To seal the apical access, delivery catheters carrying folded self-expanding plugs were inserted. Then, the plugs were deployed while sheaths were removed. Echocardiograms verified tamponade and cardiac function, drains were not placed and a 3-month long aspirin therapy was administered. After 6 and 9 months, animals were euthanized and organs were analysed for macroembolic lesions search. Histological analysis was also performed.

RESULTS

Nine minipigs (weight: 28±3 kg) were used for this study. Eight plugs were successfully deployed in 8 ventricles without cardiac tamponade or ventricular dysfunction (success rate: 88.9%). In a failed procedure (the animal died after 1 month of cardiac tamponade), the outer disc of the apical plug got stuck in the intercostal space and did not correctly deploy. Post-mortem analysis in 8 minipigs at 6 (n = 4) and 9 months (n = 4) confirmed full deployment and good fixation of all plugs with internal surfaces covered by new endocardium. Macroscopic analysis of myocardium and vital organs showed absence of embolic lesions. Histological analysis showed absence of significant inflammatory infiltration and thrombosis.

CONCLUSIONS

In this animal model, self-expanding closure devices sealed 21-Fr large percutaneous apical accesses without acute tamponade, thrombosis or embolization. Further tests to evaluate full-percutaneous closed-chest apical procedures are required.

Predictors of adverse outcomes after transcatheter mitral valve replacement

Introduction: Transcatheter mitral valve replacement (TMVR) is still a recent technology with numerous unknowns but also great promises. The risk of complications reported in observational studies have limited its adoption by interventional cardiology and surgical communities. Areas covered: Some of the major setbacks of TMVR are complications related to the devices and those related to the pathway. Device-related complications include left ventricle outflow tract (LVOT) obstruction, transcatheter heart valve (THV) dislocation or embolization, thrombosis, and stroke. The transapical approach currently remains the main pathway for TMVR but is associated with high risk of major bleeding and residual apical myocardial scarring. Complication prediction and prevention seem possible. Device-related complication prediction is based on pre-operative imaging including multi-slice computed tomography with 3-dimensional reconstructions and echocardiography which allow LVOT obstruction prediction and appropriate sizing aiming at avoiding dislocation. Industry should aim at the development of transfemoral delivery systems. Nevertheless, several recent feasibility observational studies suggested acceptable safety and efficacy of transcatheter mitral valve replacement. Expert opinion: TMVR complications and transapical delivery are some of the main setbacks which need to be addressed for TMVR to be adopted for broad clinical use.