Transcatheter Mitral Valve Replacement

Recent Developments in Catheter-based Cardiac Procedures

Since the first transcatheter aortic valve implantation in 2002, catheter-based cardiac procedures have increased significantly. This review provides an overview of CE approved devices, updated guidelines, and the key clinical findings for TAVR as well as for AV Valve interventions. Recent studies compare balloon-expanding and self-expanding valves, highlighting differences in prosthesis mismatch and paravalvular leaks. Long-term trials confirm TAVR's efficacy, especially in low-risk patients. Challenges include paravalvular regurgitation, vascular complications, and coronary obstruction, with innovations like the BASILICA procedure addressing risks. Local anesthesia in TAVR shows benefits over general anesthesia. As TAVR expands to younger patients, optimizing management pathways and addressing complications remain critical for improved outcomes.

Transcatheter Mitral Valve Replacement With Atrial Fixation for Treatment of Atrial Functional Mitral Regurgitation

BACKGROUND

Many patients with atrial functional mitral regurgitation are not suitable candidates for surgery or transcatheter repair. For transcatheter mitral valve replacement, a common contraindication is the risk of left ventricular outflow tract obstruction, particularly in patients with atrial functional mitral regurgitation, who have characteristically small left ventricles. Herein, we examine the outcomes of transcatheter mitral valve replacement using the AltaValve system, which employs atrial fixation thus minimizing left ventricular outflow tract obstruction risk.

METHODS

Patients with severe, symptomatic mitral regurgitation who were treated in the AltaValve early feasibility study or on the basis of a compassionate use exemption. The definition of atrial functional mitral regurgitation required the presence of: (1) severe mitral regurgitation; (2) atrial fibrillation; (3) normal left ventricular size; (4) left ventricular ejection fraction ≥50%; and (5) absence of organic mitral disease. Procedural outcomes, 30-day survival, and echo findings are reported.

RESULTS

Fourteen patients (71% women, mean age 77.9 years, Society of Thoracic Surgeons Predicted Risk of Mortality score 5.4%) were treated, including 11 via transseptal delivery and 3 via a transapical approach. Technical success and mitral regurgitation reduction from severe to none/trace were achieved in all cases. There were no cases of left ventricular outflow tract obstruction. All-cause mortality at 30 days was 14% (2/14). Class III/IV New York Heart Association status was reduced from 79% at baseline to 0% at 30 days. At 30 days, 11 of 12 surviving patients had an available echocardiogram; mitral regurgitation severity was trace/none in 90.9% (10/11) and mild in 9.1% (1/11).

CONCLUSIONS

The AltaValve system shows promising early procedural and clinical results for the unique anatomy of patients with atrial functional mitral regurgitation. Long-term clinical studies to demonstrate the benefit of this system are warranted.

Kissing balloon technique as rescue strategy to treat left ventricular outflow tract obstruction after transcatheter mitral valve replacement: a case report

Background

Transcatheter mitral valve replacement (TMVR) has become a viable, minimally invasive treatment for inoperable patients with severe mitral valve disease, particularly among elderly individuals with significant comorbidities. A key complication of TMVR is left ventricular outflow tract (LVOT) obstruction, necessitating various preventive and therapeutic strategies. This report presents a case of severe LVOT obstruction following TMVR and highlights the effective application of the kissing balloon technique as a therapeutic intervention.

Case summary

A 79-year-old female with New York Heart Association Class IV dyspnoea due to severe mitral stenosis and a high operative risk, with a Society of Thoracic Surgeons Risk of Mortality (STS-PROM) score of 6.2%, underwent TMVR. Pre-procedural evaluations indicated significant mitral valve calcification and a mitral valve area of 0.9 cm². After successful TMVR deployment, post-implantation echocardiography revealed an LVOT pressure gradient of 53/85 mmHg, prompting the use of the kissing balloon technique, which reduced the gradient to 28 mmHg. Follow-up assessments showed normal mitral valve function and stable LVOT gradients during short-term follow-up throughout the patient's hospital stay.

Discussion

Left ventricular outflow tract obstruction is a potentially life-threatening complication of TMVR, often associated with high mortality rates due to haemodynamic impairment. This complication can arise from various anatomical factors and valve positioning issues. Several strategies have been developed to address LVOT obstruction, including the laceration of the anterior mitral leaflet and alcohol septal ablation. The successful implementation of the kissing balloon technique in this case underscores its potential to improve outcomes in LVOT obstruction.

Transcatheter mitral valve repair with MitraClip® enabling single lung transplantation: A case report

Post-capillary hypertension resulting from mitral regurgitation is typically considered a contraindication for single lung transplantation due to heightened risks of primary graft dysfunction. This case report highlights a 66-year-old COPD patient with severe mitral regurgitation who was deemed ineligible for surgical mitral replacement. As an alternative, transcatheter mitral valve replacement was successfully performed, resulting in the normalization of pulmonary artery pressures. Consequently, the patient became eligible for single lung transplantation, which was conducted successfully in the subsequent months. Eighteen months post-lung transplantation, the patient now experiences a normal functional status and excellent lung function. In conclusion, transcatheter mitral valve replacement appears to be a safe alternative to surgery for normalizing post-capillary pulmonary hypertension in patients with chronic respiratory diseases. This approach could potentially facilitate lung transplantation (LTx) in eligible candidates.

Ten-Year Experience with a Transapical Approach for Transcatheter Aortic and Mitral Valve Implantation

BACKGROUND

The transfemoral approach represents the optimal access for TAVI due to its low invasiveness; however, up to 10-15% of TAVI candidates are considered unsuitable for femoral access because of significant peripheral vascular disease and need alternative access.

METHODS

This is a single-center retrospective observational study including all consecutive adult patients undergoing transcatheter procedures through a TA approach from March 2015 to April 2024.

RESULTS

213 patients underwent transcatheter aortic or mitral valve implantation through a TA approach and were enrolled in this study. The mean age of the patients was 79.5 ± 5.7 years, and 54% of the patients were males. The mean Euroscore II was 7.9 ± 6.4%. One-third of the patients had previous cardiac surgery. The overall mean survival time was 5.3 ± 0.3 years. Nine (4%) patients developed infective endocarditis (IE) during the follow-up.

CONCLUSIONS

The transapical approach for transcatheter procedures is a safe and effective procedure for patients unsuitable for TF access with low periprocedural mortality and a low rate of post-procedural complications when performed by experienced surgeons and cardiologists.

Anterior mitral leaflet laceration using the MitraCut technique for transapical transcatheter Tendyne implantation after unsuccessful Carillon indirect annuloplasty: a case report

Background

The introduction of a transapical transcatheter beating heart replacement system has significantly expanded therapeutic options for patients with severely diseased mitral valves, particularly those ineligibles for traditional surgery or transcatheter repair. However, challenges, such as left ventricular outflow tract obstruction (LVOT-O) and the risk of dynamic systolic anterior motion (SAM) in cases with elongated anterior mitral leaflet (AML) post-prosthesis implantation, impede the widespread adoption of transcatheter mitral valve replacement (TMVR).

Case summary

In 2022, a 75-year-old male with severe mixed-genesis mitral regurgitation (MR) underwent Carillon Mitral Contour System annuloplasty. Recurrent heart failure admissions (New York Heart Association IV) and prohibitive risk for open-heart surgery (European System for Cardiac Operative Risk Evaluation II 8.27%) prompted evaluation for Tendyne TMVR with the MitraCut technique. This beating heart transapical approach involved scissor-mediated splitting of the elongated 27 mm AML, essential for mitigating LVOT-O risk and dynamic SAM. The screening echocardiogram revealed the poorly tethered AML near the thickened septum at the simulated neo-LVOT site.

Discussion

This case underscores the intricate management challenges associated with severe MR, highlighting the successful application of the MitraCut technique as a viable alternative in high-risk scenarios. The imperative for further research and clinical studies is emphasized to comprehensively elucidate outcomes and safety parameters, providing valuable insights for refining TMVR applications within this context.

Biorobotic hybrid heart as a benchtop cardiac mitral valve simulator

In this work, we developed a high-fidelity beating heart simulator that provides accurate mitral valve pathophysiology. The benchtop platform is based on a biorobotic hybrid heart that combines preserved intracardiac tissue with soft robotic cardiac muscle providing dynamic left ventricular motion and precise anatomical features designed for testing intracardiac devices, particularly for mitral valve repair. The heart model is integrated into a mock circulatory loop, and the active myocardium drives fluid circulation producing physiological hemodynamics without an external pulsatile pump. Using biomimetic soft robotic technology, the heart can replicate both ventricular and septal wall motion, as well as intraventricular pressure-volume relationships. This enables the system to recreate the natural motion and function of the mitral valve, which allows us to demonstrate various surgical and interventional techniques. The biorobotic cardiovascular simulator allows for real-time hemodynamic data collection, direct visualization of the intracardiac procedure, and compatibility with clinical imaging modalities.

Transcatheter mitral valve implantation for native valve disease

Mitral regurgitation is the second most frequent heart valve disease in Europe and the most frequent in the US. Although surgery is the therapy of choice when intervention is indicated, transcatheter mitral valve repair or replacement are alternatives for patients who are not eligible for surgery. However, the development of transcatheter mitral valves is slower than expected. Although several transcatheter heart valves have been developed, only one has been commercialised. Indeed, most of these devices are being evaluated in clinical studies, with promising initial results. In this review, we propose an overview on transcatheter mitral valve replacement for the treatment of native mitral valve disease, from indication to results, including patients with severe annular calcification, and we provide you with a glimpse into the future of these therapies.

Spontaneously Resolved Systolic Anterior Motion of Native Mitral Valve Leaflet After Transcatheter Mitral Valve Replacement

Systolic anterior motion of a mitral leaflet can occur by various mechanisms and it is one of the causes of left ventricular outflow tract obstruction after transcatheter mitral valve replacement. We present a case of systolic anterior motion that resolved spontaneously as the anterior mitral leaflet adhered to the prosthesis. (Level of Difficulty: Intermediate.).

Trans-catheter mitral valve-in-valve replacement in a patient on venoarterial extracorporeal membrane oxygenation: a case report

Background

Bioprosthetic mitral valves on average have a median durability between 8 and 10 years. After the failure of a bioprosthetic valve, surgical replacement is often indicated. However, the options for those patients at high or prohibitive surgical risks are limited. Here, we describe a case of a successful trans-catheter mitral valve-in-valve (TMViV) replacement on venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Case summary

We describe a case of a 39-year-old female with a history notable for systemic lupus erythematosus, severe pulmonary arterial hypertension (now mixed pre and post) thought to be secondary to prior substance use, and infective endocarditis complicated by severe mitral stenosis status post-bioprosthetic mitral valve replacement who presented with symptoms of acute hypoxic respiratory failure secondary to severe bioprosthetic mitral valve stenosis. The patient had a prolonged hospital course complicated by a pulseless electrical activity arrest, (continuous renal replacement therapy) for acute renal failure, and hypertonic saline due to cerebral oedema. Due to her significant co-morbidities and haemodynamic instability with acute kidney injury and recent neurologic insult, the patient was thought not to be a good surgical candidate. However, given her young age and overall improved neurologic status, it was thought the patient could benefit from a TMViV with bi-ventricular support given her right- and left-sided heart failure and was placed on VA-ECMO in anticipation of a TMViV procedure for circulatory support. The patient underwent a successful TMViV replacement using a trans-septal approach with a 26 mm SAPIEN 3 valve and atrial septal defect closure with a 14 mm Amplatzer device on hospital Day 12. The patient was successfully de-cannulated from VA-ECMO on hospital Day 13. The patient had a prolonged hospital course but eventually had renal recovery and tracheostomy de-cannulation. A trans-thoracic echocardiogram prior to discharge was notable for a well-functioning valve and normal ejection fraction. The patient was discharged to a nursing home for further rehabilitation.

Discussion

The gold standard for bioprosthetic mitral valve stenosis is surgical replacement of the valve. However, the options for those at high or prohibitive surgical risk are lacking. Recent studies have demonstrated TMViV is a safe alternative to surgical mitral valve redo cases in high-risk patients. To our knowledge, there are limited data on trans-catheter valve placement while on VA-ECMO. Successful implantation in our patient suggests that TMViV in a stenotic bioprosthesis is feasible in very high-risk patients with the use of VA-ECMO to support haemodynamics.

Simultaneous transcatheter dual valve replacement (mitral and tricuspid valves): a case report

Background

Structural valve dysfunction in bioprosthetic heart valves necessitates redo replacement procedure that are associated with high mortality and morbidity. The transcatheter valve-in-valve (VIV) approach has emerged as a preferred option for patients requiring redo procedures due to structural valve degeneration. We report from India the first case of the simultaneous transcatheter dual VIV implantation (mitral valve and tricuspid valves) in a high-surgical-risk patient.

Case summary

A 57-year-old female was presented with a history of rheumatic heart disease, post-mitral valve as well as tricuspid valve replacement (perimount 33 mm) 11 years back. Bioprosthetic heart valve was chosen probably due to limited life expectancy and compliance issues with monitoring of international normalised ratio (INR). She now presented with progressive dyspnoea, oedema, and palpitations (New York Heart Association Class III) for the last 6 months. The patient was scheduled for transcatheter dual valve replacement simultaneously. The procedure was successful with a favourable outcome, short hospital stays, and early recovery.

Discussion

This is the first case of simultaneous transcatheter dual valve replacement reported from India, which is fluoroscopically guided and supported by TEE. It is a valuable and considerable option for patients with failing bioprosthesis valves who are at increased peri-operative risk.

Current status of transcatheter mitral valve replacement: systematic review and meta-analysis

INTRODUCTION

Mitral Regurgitation (MR) has a strong impact on quality of life and on mid-term survival. Transcatheter mitral valve replacement (TMVR) is rapidly expanding and a growing number of studies have been published recently.

METHODS

A systematic review of studies reporting on clinical data for patients with symptomatic severe MR undergoing TMVR was performed. Early- and mid-term outcomes (clinical and echocardiographic) were evaluated. Overall weighted means and rates were calculated. Risk ratios or mean differences were calculated for pre- and post-procedural comparisons.

RESULTS

A total of 12 studies and 347 patients who underwent TMVR with devices clinically available or under clinical evaluation were included. Thirty-day mortality, stroke and major bleeding rates were 8.4%, 2.6%, and 15.6%, respectively. Pooled random-effects demonstrated a significant reduction of ≥ grade 3+ MR (RR: 0.05; 95% CI: 0.02-0.11; p < 0.001) and in the rates of patients in NYHA class 3-4 after the intervention (RR: 0.27; 95% CI: 0.22-0.34; p < 0.001). Additionally, the pooled fixed-effect mean difference for quality of life based on the KCCQ score yielded an improvement in 12.9 points (95% CI:7.4-18.4, p < 0.001), and exercise capacity improved by a pooled fixed-effect mean difference of 56.8 meters in the 6-minute walk test (95% CI 32.2-81.3, p < 0.001).

CONCLUSIONS

Among 12 studies and 347 patients comprising the updated evidence with current TMVR systems there was a statistically significant reduction in ≥ grade 3+ MR and in the number of patients exhibiting poor functional class (NYHA 3 or 4) after the intervention. Overall rate of major bleeding was the main shortcoming of this technique.

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.

Impact of sex on in-hospital mortality and 90-day readmissions in patients undergoing transcatheter mitral valve replacement (TMVR): Analysis from the nationwide readmission database

OBJECTIVES

To evaluate sex differences in in-hospital mortality and 90-day readmission rates among patients undergoing transcatheter mitral valve replacement (TMVR) in the United States of America.

BACKGROUND

Women have higher rates of mortality and rehospitalization than men following many cardiac procedures. TMVR has grown as an alternative to mitral valve surgery for patients at high surgical risk. The rates of TMVR mortality and rehospitalization by sex are unknown.

METHODS

We analyzed the Nationwide Readmissions Database (NRD) from 2016 to 2019 to identify hospitalizations for TMVR. Sex differences in in-hospital mortality and 90-day readmissions were determined using logistic regression models.

RESULTS

Between 2016 and 2019, 4109 hospitalizations for TMVR were identified, comprised of 1758 (42.8%) men and 2351 (57.2%) women. The median age was 74 years for both men and women. There was no significant difference in in-hospital mortality during index hospitalization (6.51% vs. 6.69%; p = 0.852) and all-cause 90-day readmission (28.19% vs. 29.59%; p = 0.563) between men and women. Across the study period, trend analysis did not reveal a significant change in in-hospital mortality (men p = 0.087, women p = 0.194) or 90-day readmission rates (men p = 0.569, women p = 0.454).

CONCLUSIONS

In patients undergoing TMVR, in-hospital mortality and 90-day readmissions are similar between men and women. Between 2016 and 2019, TMVR in-hospital mortality and 90-day readmission rates remained unchanged. Further research is necessary to confirm these findings.

Survival benefit of overweight patients undergoing MitraClip® procedure in comparison to normal-weight patients

BACKGROUND

The number of MitraClip® implantations increased significantly in recent years. Data regarding the impact of weight class on survival are sparse.

HYPOTHESIS

We hypothesized that weight class influences survival of patients treated with MitraClip® implantation.

METHODS

We investigated in-hospital, 1-year, 3-year, and long-term survival of patients successfully treated with isolated MitraClip® implantation for mitral valve regurgitation (MR) (June 2010-March 2018). Patients were categorized by weight classes, and the impact of weight classes on survival was analyzed.

RESULTS

Of 617 patients (aged 79.2 years; 47.3% females) treated with MitraClip® implantation (June 2010-March 2018), 12 patients were underweight (2.2%), 220 normal weight (40.1%), 237 overweight (43.2%), and 64 obesity class I (11.7%), 12 class II (2.2%), and 4 class III (0.7%). Preprocedural Logistic EuroScore (21.1 points [IQR 14.0-37.1]; 26.0 [18.5-38.5]; 26.0 [18.4-39.9]; 24.8 [16.8-33.8]; 33.0 [25.9-49.2]; 31.6 [13.1-47.6]; p = .291) was comparable between groups. Weight class had no impact on in-hospital death (0.0%; 4.1%; 1.5%; 0.0%; 7.7%; 0.0%; p = .189), 1-year survival (75.0%; 72.0%; 76.9%; 75.0%; 75.0%; 33.3%; p = .542), and 3-year survival (40.0%; 36.8%; 38.2%; 48.6%; 20.0%; 33.3%; p = .661). Compared to normal weight, underweight (hazard ratio [HR]: 1.35 [95% confidence interval [CI]: 0.65-2.79], p = .419), obesity-class I (HR: 0.93 [95% CI: 0.65-1.34], p = .705), class II (HR: 0.39 [95% CI: 0.12-1.24], p = .112), and class III (HR: 1.28 [95% CI: 0.32-5.21], p = .726) did not affect long-term survival. In contrast, overweight was associated with better survival (HR: 1.32 [95% CI: 1.04-1.68], p = .023).

CONCLUSION

Overweight affected the long-term survival of patients undergoing MitraClip® implantation beneficially compared to normal weight.

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.

Radiofrequency Ablation for Prevention of Outflow Tract Obstruction in Percutaneous Mitral Valve-in-Valve Replacement

Left ventricular outflow tract obstruction (LVOTO) can complicate percutaneous mitral valve replacement and may preclude patients considered high surgical risk from transcatheter therapies. We report a case of mitral valve-in-valve procedure in a patient at high risk for LVOTO. (Level of Difficulty: Advanced.)

Mitral Valve Replacement: A Review of Current Practices and Considerations in Low and High-Risk Patients

Mitral Regurgitation (MR) is the most common form of severe valvular disease occurring in developed countries, being caused either primarily on its own or secondary to cardiac disease. Surgical intervention is required for the correction of MR, which could include the replacement or repair of the affected valve. Transcatheter Mitral Valve Replacement (TMVR) in selected patients is of increasing importance, especially after the success of Transcatheter Aortic Valve Replacement (TAVR). TMVR can be divided into three types i.e., valve-in-valve (ViV) for severe mitral valve disease, valve-in-ring (ViR) for failed surgical repairs, and valve-in-mitral annular calcifications (ViMAC) for mitral valvular disease with severe mitral annular calcifications and poor surgical criteria. The FDA approved Mitral ViV for patients with a high surgical risk in 2017, while ViR and ViMAC are still currently under consideration. The SAPIEN M3 valve is relatively new with a trans-septal system, with a success rate of 86%, and no mortality in a 30-day outcome. The Cardiovalve is a bovine pericardium device that has a dual nitinol frame with a custom surgical design to facilitate TMVR. The AHEAD trial will evaluate whether the device is safe to use in a clinical setting and how effective it is for reducing MR in these patients. The trial consists of 30 patients in which the first 5 patients showed 100% technical success and a reduction of MR. This evolution of modern medicine has assisted in many different countries, including Pakistan where there is a higher prevalence of MR and hence, a greater need to apply TMVR in clinical practice.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Transcatheter Mitral Valve Repair or Replacement: Competitive or Complementary?

Over the last two decades, transcatheter devices have been developed to repair or replace diseased mitral valves (MV). Transcatheter mitral valve repair (TMVr) devices have been proven to be efficient and safe, but many anatomical structures are not compatible with these technologies. The most significant advantage of transcatheter mitral valve replacement (TMVR) over transcatheter repair is the greater and more reliable reduction in mitral regurgitation. However, there are also potential disadvantages. This review introduces the newest TMVr and TMVR devices and presents clinical trial data to identify current challenges and directions for future research.

CT in Transcatheter-delivered Treatment of Valvular Heart Disease

Minimally invasive strategies to treat valvular heart disease have emerged over the past 2 decades. The use of transcatheter aortic valve replacement in the treatment of severe aortic stenosis, for example, has recently expanded from high- to low-risk patients and became an alternative treatment for those with prohibitive surgical risk. With the increase in transcatheter strategies, multimodality imaging, including echocardiography, CT, fluoroscopy, and cardiac MRI, are used. Strategies for preprocedural imaging strategies vary depending on the targeted valve. Herein, an overview of preprocedural imaging strategies and their postprocessing approaches is provided, with a focus on CT. Transcatheter aortic valve replacement is reviewed, as well as less established minimally invasive treatments of the mitral and tricuspid valves. In addition, device-specific details and the goals of CT imaging are discussed. Future imaging developments, such as peri-procedural fusion imaging, machine learning for image processing, and mixed reality applications, are presented.

Appropriateness criteria for the use of cardiac computed tomography, SIC-SIRM part 2: acute chest pain evaluation; stent and coronary artery bypass graft patency evaluation; planning of coronary revascularization and transcatheter valve procedures; cardiomyopathies, electrophysiological applications, cardiac masses, cardio-oncology and pericardial diseases evaluation

In the past 20 years, cardiac computed tomography (CCT) has become a pivotal technique for the noninvasive diagnostic workup of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Randomized clinical trials documented the value of CCT in increasing the cost-effectiveness of the management of patients with acute chest pain presenting in the emergency department, also during the pandemic. Beyond the evaluation of stents and surgical graft patency, the anatomical and functional coronary imaging have the potential to guide treatment decision-making and planning for complex left main and three-vessel coronary disease. Furthermore, there has been an increasing demand to use CCT for preinterventional planning in minimally invasive procedures, such as transcatheter valve implantation and mitral valve repair. Yet, the use of CCT as a roadmap for tailored electrophysiological procedures has gained increasing importance to assure maximum success. In the meantime, innovations and advanced postprocessing tools have generated new potential applications of CCT from the simple coronary anatomy to the complete assessment of structural, functional and pathophysiological biomarkers of cardiac disease. In this complex and revolutionary scenario, it is urgently needed to provide an updated guide for the appropriate use of CCT in different clinical settings. This manuscript, endorsed by the Italian Society of Cardiology (SIC) and the Italian Society of Medical and Interventional Radiology (SIRM), represents the second of two consensus documents collecting the expert opinion of cardiologists and radiologists about current appropriate use of CCT.

Prosthetic cardiac valves: history and review of cardiac prostheses clinically available in Japan

Recently developed prosthetic valves are reliable and essential for the treatment of valvular heart disease. The mechanical valve evolved remarkably following the introduction of pyrolite carbon material, which enabled the creation of a bileaflet form incorporated with a pivot mechanism. The improved durability of the biological valve is attributed mainly to the development of a tissue fixation process and anti-calcification treatments. However, optimal antithrombogenicity and durability have not yet been achieved for either prosthetic valve type. To select the most suitable prosthetic valve for each individual patient from among the many clinically available prosthetic valves, it is necessary to have a thorough understanding of the characteristics of each valve.

Cardiac Computed Tomography: Application in Valvular Heart Disease

The incidence and prevalence of valvular heart disease (VHD) is increasing and has been described as the next cardiac epidemic. Advances in imaging and therapeutics have revolutionized how we assess and treat patients with VHD. Although echocardiography continues to be the first-line imaging modality to assess the severity and the effects of VHD, advances in cardiac computed tomography (CT) now provide novel insights into VHD. Transcatheter valvular interventions rely heavily on CT guidance for procedural planning, predicting and detecting complications, and monitoring prosthesis. This review focuses on the current role and future prospects of CT in the assessment of aortic and mitral valves for transcatheter interventions, prosthetic valve complications such as thrombosis and endocarditis, and assessment of the myocardium.

CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR)

BACKGROUND

 Transcatheter mitral valve replacement (TMVR) is a treatment option for patients with therapy refractory high-grade mitral valve regurgitation and a high perioperative risk.During TMVR, the mitral annulus cannot be visualized directly. Therefore, comprehensive pre-interventional planning and a precise visualization of the patient's specific mitral valve anatomy, outflow tract anatomy and projected anchoring of the device are necessary.Aim of this review-article is, to assess the role of pre-procedural computed tomography (CT) for TMVR-planning METHODS:  Screening and evaluation of relevant guidelines (European Society of Cardiology [ESC], American Heart Association [AHA/ACC]), meta-analyses and original research using the search terms "TVMR" or "TMVI" and "CT". In addition to this, the authors included insight from their own clinical experience.

RESULTS

 CT allows for accurate measurement of the mitral annulus with high special and adequate temporal resolution in all cardiac phases. Therefore, CT represents a valuable method for accurate prosthesis-sizing.In addition to that, CT can provide information about the valvular- and outflow-tract-anatomy, mitral valve calcifications, configuration of the papillary muscles and of the left ventricle. Additionally, the interventional access-route may concomitantly be visualized.

CONCLUSION

 CT plays, in addition to echocardiographic imaging, a central role in pre-interventional assessment prior to TMVR. Especially the precise depiction of the left ventricular outflow tract (LVOT) provides relevant additional information, which is very difficult or not possible to be acquired in their entirety with other imaging modalities.

KEY POINTS

  · CT plays a central role in pre-interventional imaging for TMVR.. · CT-measurements allow for accurate prosthesis-sizing.. · CT provides valuable information about LVOT-anatomy, mitral calcifications and interventional access-route..

CITATION FORMAT

· Heiser L, Gohmann RF, Noack T et al. CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR). Fortschr Röntgenstr 2022; DOI: 10.1055/a-1718-4182.

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.

Under-representation of Women as Proceduralists and Patients in TAVR and TMVr Procedures: Data, Implications and Proposed Solutions

Women are under-represented among transcatheter aortic valve replacement (TAVR) and transcatheter mitral valve repair (TMVr) operators. This review assesses the representation of women as patients and as proceduralists and trial authors in major structural interventions. Women are under-represented as proceduralists in structural interventions: only 2% of TAVR operators and 1% of TMVr operators are women. Only 1.5% of authors in landmark clinical TAVR and TMVr trials are interventional cardiologists who are women (4/260). Significant under-representation and under-enrolment of women in landmark TAVR trials is evident: the calculated participation-to-prevalence ratio (PPR) is 0.73, and in TMVr trials, the PPR is 0.69. Under-representation of women is also evident in registry data (PPR = 0.84 for TAVR registries and for TMVr registries). In structural interventional cardiology, women are under-represented as proceduralists, trial participants and patients. This under-representation has the potential to affect the recruitment of women to randomised trials, subsequent guideline recommendations, selection for treatment, patient outcomes and sex-specific data analysis.

Latest Advances in Transcatheter Mitral Valve Replacement

Mitral regurgitation (MR) is the most prevalent valvular heart disease globally. Mitral valve surgery is the gold-standard treatment for MR. However, a significant portion of patients with mitral valve disease are at high or prohibitive surgical risk. Transcatheter mitral valve replacement (TMVR) has emerged as a potential treatment option for this vulnerable population. Numerous TMVR devices are currently being investigated, with early data demonstrating feasibility and efficacy of TMVR. In this article, we explore the unique challenges of designing a TMVR system and describe the TMVR systems under clinical evaluation.

Transcatheter mitral valve intervention

Mitral regurgitation is a common valvular heart disorder increasing with age. Many patients are ineligible for mitral valve surgery due to their age and other comorbidities. Left untreated, patients develop severe disease with a poor prognosis. The development of lower risk percutaneous mitral valve interventions has helped meet the needs of this previously untreated patient group. This review explores the recent and more established developments that have expanded the armamentarium for transcatheter mitral valve intervention.

Antithrombotic Therapy in Patients Undergoing Transcatheter Interventions for Structural Heart Disease

Contemporary evidence supports device-based transcatheter interventions for the management of patients with structural heart disease. These procedures, which include aortic valve implantation, mitral or tricuspid valve repair/implantation, left atrial appendage occlusion, and patent foramen ovale closure, profoundly differ with respect to clinical indications and procedural aspects. Yet, patients undergoing transcatheter cardiac interventions require antithrombotic therapy before, during, or after the procedure to prevent thromboembolic events. However, these therapies are associated with an increased risk of bleeding complications. To date, challenges and controversies exist regarding balancing the risk of thrombotic and bleeding complications in these patients such that the optimal antithrombotic regimens to adopt in each specific procedure is still unclear. In this review, we summarize current evidence on antithrombotic therapies for device-based transcatheter interventions targeting structural heart disease and emphasize the importance of a tailored approach in these patients.

Transcatheter mitral valve therapies: State of the art

Mitral regurgitation (MR) is one of the most prevalent valvular pathologies in the developed world. There continues to be a growing population of aging patients with MR who may be too high risk for surgical management. The rapid adoption and remarkable success of transcatheter aortic valve replacement (TAVR) generated enthusiasm for transcatheter mitral valve therapies; however, the complex anatomy and pathophysiology of the mitral valve confers several unique challenges for a fully percutaneous approach. Nevertheless, several devices are under development and in various phases of preclinical or clinical testing, both for transcatheter mitral valve replacement and repair. MitraClip (Abbott Vascular), which has received FDA approval, is the most established percutaneous repair strategy and has been performed in over 80,000 patients as of 2019. The following article serves as a review of the available and upcoming devices for the various etiologies of mitral valvular disease, as well as the unique challenges and potential complications of transcatheter mitral valve intervention.

Access options for transcatheter mitral valve implantation in patients with prior surgical bioprosthesis

BACKGROUND

Transcatheter mitral valve-in-valve (TMVIV) procedure, either transapical (TA) or trans-septal (TS) has become a valuable alternative to conventional redo surgery in case of failing mitral bioprosthesis with good clinical outcomes. Here we present our fourteen-year institutional experience.

METHODS

All consecutive patients treated with TMVIV with either TA or TS access at our centre between July 2007 and July 2020 were included. Periprocedural and 30-day follow-up (FU) results are reported and TA and TS data are compared.

RESULTS

Eighty-two patients were included, of those 60 (73.2%) were TA while 22 (26.8%) were TS. Men represented 51.2% of the population with a mean age of 77.3±9.0 years. STS score and EuroSCORE II were 11.4%±6.2% and 11.5%±6.5% respectively. Baseline characteristics of TA and TS groups were comparable. TMVIV was performed at a median time of 9.3 years [interquartile range (IQR), 7.9-12.0 days] from the initial mitral valve surgery. Balloon expandable transcatheter heart valve (THV) prostheses (Edwards LifeSciences Corp., Irvine, CA, USA) were used exclusively. Technical success was 97.6% (96.7% and 100.0% for TA and TS respectively) with two (2.4%) periprocedural death, both in the TA group (P=0.533). We observed four (4.9%) left ventricular outflow tract (LVOT) obstructions with one being hemodynamically significant. Six (7.3%) major bleeding occurred in the TA group, not significantly different from TS group (P=0.279). The median length of stay was 6 days (IQR, 4-12 days, 1.5 vs. 7.0 days for TS and TA groups respectively, P=0.001). The overall 30-day mortality rate was 3.7%. We also observed three (3.7%) structural valve deteriorations and in one (1.2%) case the patient required redo mitral surgery at two months. Eighty-seven-point-eight percent of patients were I-II New York Heart Association (NYHA) class. At 30-day FU mean transmitral valve gradient was 7.3±2.7 mmHg and one patient (1.2%) had mitral regurgitation greater than mild. TA and TS groups were comparable.

CONCLUSIONS

Our 14-year single-center experience with TMVIV confirms procedural safety and is an effective alternative to redo surgery with comparable results with both TA and TS. With device, technical improvements and increasing operators' experience, TS is the preferred option for TMVIV. However, in some highly selected patient, TA may still play an important role.

Mitral surgical redo versus transapical transcatheter mitral valve implantation

Background

Transcatheter methods have been rapidly evolving to provide an alternative less invasive therapeutic option, mainly because redo patients often present with multiple comorbidities and high operative risk. We sought to evaluate and compare our experience with transapical transcatheter mitral valve replacement (TA-TMVR) to conventional redo mitral valve replacement in patients presenting with degenerated biological mitral valve prostheses or failed valve annuloplasty.

Methods and material

Between March 2012 and November 2020, 74 consecutive high-risk patients underwent surgical redo mitral valve replacement (n = 33) or TA-TMVR (n = 41) at our institution. All patients presented with a history of a surgical mitral valve procedure. All transcatheter procedures were performed using the SAPIEN XT/3™ prostheses. Data collection was prospectively according to MVARC criteria.

Results

The mean logistic EuroSCORE-II of the whole cohort was 19.9±16.7%, and the median STS-score was 11.1±12.5%. The mean age in the SMVR group was 63.7±12.8 years and in the TMVR group 73.6±9.7 years. Patients undergoing TA-TMVR presented with significantly higher risk scores. Echocardiography at follow up showed no obstruction of the left ventricular outflow tract, no paravalvular leakage and excellent transvalvular gradients in both groups (3.9±1.2 mmHg and 4.2±0.8 mmHg in the surgical and transcatheter arm respectively). There was no difference in postoperative major adverse events between the groups with no strokes in the whole cohort. Both methods showed similar survival rates at one year and a 30-day mortality of 15.2% and 9.8% in SAVR and TMVR group, respectively. Despite using contrast dye in the transcatheter group, the rate of postoperative acute kidney failure was similar between the groups.

Conclusion

Despite several contraindications for surgery, we showed the non-inferiority of TA-TMVR compared to conventional surgical redo procedures in high-risk patients. With its excellent hemodynamic and similar survival rate, TA-TMVR offers a feasible alternative to the conventional surgical redo procedure in selected patients.

Transcatheter Mitral Valve Implantation: Current Status and Future Perspectives

Mitral transcatheter therapies represent the treatment of choice for all patients deemed unsuitable for cardiac surgery. So far, the largest clinical experience has been limited to percutaneous repair techniques. However, given the complexity and heterogeneity of mitral valve anatomy and pathology, transcatheter mitral valve implantation will widen the mitral valve therapies horizon, toward a patient-tailored approach. Current data about transcatheter mitral valve implantation is still limited and, although some data are promising, there are still some issues to be addressed. This review provides a comprehensive insight into the available devices and describes potential advantages and limitations of transcatheter mitral valve implantation.

Transapical Transcatheter Mitral Valve Implantation in Heart Failure: Haemodynamic Challenges for a New Frontier

Secondary mitral regurgitation (MR) and heart failure are mutually dependent. Secondary MR occurs as a consequence of heart failure in patients with impaired left ventricular (LV) function, decreasing cardiac efficiency, accelerating a decline in contractility and worsening the already dismal prognosis of these patients. Advances in transcatheter techniques have now given promise to improved survival, outcomes, and quality of life for patients with advanced heart failure and secondary MR. Although transcatheter edge-to-edge repair is well established, transapical transcatheter mitral valve implantation (TMVI) may represent a more durable solution for correction of secondary MR without the need for cardiopulmonary bypass. Correction of MR, however, is thought to acutely increase LV afterload due to the elimination of low afterload regurgitant flow. In high-risk patients, this may cause acute decompensated heart failure. Off-pump TMVI on a beating heart poses a number of unique challenges, but also the opportunity to study invasive haemodynamic indices in high-risk heart failure patients for the first time. In the following discussion, we review the acute haemodynamic changes during off-pump TMVI in patients with heart failure in order to better guide optimal patient selection and management.

CT for Pre- and Postprocedural Evaluation of Transcatheter Mitral Valve Replacement

Transcatheter mitral valve replacement (TMVR) is a catheter-based interventional technique for treating mitral valve disease in patients who are at high risk for open mitral valve surgery and with unfavorable anatomy for minimally invasive edge-to-edge transcatheter mitral valve repair. There are several TMVR devices with different anchoring mechanisms, delivered by either transapical or transseptal approaches. Transthoracic echocardiography is the first-line imaging modality used for characterization and quantification of mitral valve disorders. CT is complementary to echocardiography and has several advantages, including high isotropic spatial resolution, good temporal resolution, large field of view, multiplanar reconstruction capabilities, and rapid turnaround time. CT is essential for multiple aspects of preprocedural planning. Accurate and reproducible techniques to prescribe the mitral annulus at CT have been described from which important measurements such as the area, perimeter, trigone-trigone distance, intercommissural distance, and septolateral distance are obtained. The neo-left ventricular outflow tract (LVOT) can be simulated by placing a virtual prosthesis in the CT data to predict the risk of TMVR-induced LVOT obstruction. The anatomy of the landing zone and subvalvular apparatus as well as the relationship of the virtual device to adjacent structures such as the coronary sinus and left circumflex coronary artery can be evaluated. CT also stimulates procedural fluoroscopic angles. CT can be used to evaluate the chest wall for transapical access and the atrial septum for transseptal access. Follow-up CT is useful in identifying complications such as LVOT obstruction, paravalvular leak, pseudoaneurysm, and valve embolization. Online supplemental material is available for this article. ^©RSNA, 2020.

Current Status of Catheter-based Mitral Valve Replacement

PURPOSE OF REVIEW

Transcatheter mitral valve replacement (TMVR) has been developed to address the need for an alternative therapeutic option to surgery in patients suffering from severe mitral regurgitation who are at high surgical risk. The present review illustrated the state-of-the-art of catheter-based mitral valve replacement evaluating technical characteristics and early clinical experience of different devices to outline prospects and challenges of TMVR.

RECENT FINDINGS

Several devices are currently under clinical assessment. Early experience has demonstrated high procedural success of TMVR. However, TMVR faces several possible hurdles such as left ventricular outflow tract obstruction (LVOTO) after prosthesis deployment, access site complications, and thrombotic risk requiring anticoagulatory therapy. Future studies should assess long-term prosthesis stability, optimal anticoagulation regime, and occurrence of paravalvular leakage. The development of smaller TMVR prostheses suitable for transseptal implantation could overcome bleeding complications. In perspective, TMVR may emerge to a clinically relevant therapeutic approach for patients with severe MR at high surgical risk.

Preoperative mitral annulus size - Can we get it right?

Objective

We looked for a correlation between the surgically measured mitral valve size and the cardiac dimensions (left ventricle internal diameter, left atrial size, aorta size, and body surface area) measured by preoperative and intraoperative echocardiography. We also assessed to see if we could predict the mitral prosthesis size based on the correlation data obtained.

Methods

The hospital records of 180 patients who underwent mitral valve replacement (MVR) with TTK Chitra valve between January 2008 and December 2012 at our hospital, were studied. The correlation between surgically measured mitral annulus size to left ventricular internal diameter systolic (LVIDS) and diastolic (LVIDD), left atrial size (linear measurement), and aorta size on echocardiography and body surface area was calculated using Pearson correlation coefficient. Mean LVIDS was calculated for each valve prosthesis size separately and the correlation was studied.

Results

The correlation between mitral valve prosthesis size and left ventricular internal diameter (systolic) showed a Pearson coefficient of 3.3 with significance at the level 0.01. Mitral valve size and left atrial size showed a correlation coefficient of 2.7 with significance at the level 0.01. The correlation coefficient for mitral valve size with left ventricular internal diameter diastolic, aorta and body surface area were 2.5, 1.9, and 1.8, respectively. There was a gradual increase in the mean LVIDS with increase in the prosthetic valve size. Box plot and scatter plot showed linear correlation between valve size and mean LVIDS.

Simultaneous transcatheter treatment of ascending aortic aneurysm with aortic and mitral regurgitation: an in vitro study

OBJECTIVES

We sought to explore the efficacy of the endovascular repair of an ascending aortic aneurysm with aortic and mitral regurgitation by 2 novel valved stents.

METHODS

We established models of ascending aortic aneurysms combined with aortic and mitral regurgitation in 10 pig hearts, then implanted self-expanding aortic fenestrated and mitral valved stents via the transapical approach. We applied a fluoroscopy-guided in vitro setting to test the approach, then analysed continuous circulating flushing at 37°C. Finally, we determined operating times, echocardiography and changes of coronary flow as well as fenestration alignment with the coronary ostia.

RESULTS

This approach resulted in a 100% overall technical success rate, excellent handling properties and precise positioning. The time taken to implant the 2 valved stents was 59 ± 12 min. Flow of the left and right coronary arteries did not significantly decrease after the stents were implanted (330.4 ± 12.06 ml/min vs 289.4 ± 5.29 ml/min, P < 0.001; 376.8 ± 10.5 ml/min vs 350.0 ± 14.5 ml/min; P < 0.001). We found no obvious regurgitation and perivalvular leakage; nor did the gradients of the aortic and mitral valves as well as of the left ventricular outflow tract increase significantly. The final angiographic examination and profile of the coronary opening confirmed the good position of the valved stents, the exclusion of the aneurysm and the patency of both coronary arteries.

CONCLUSIONS

These findings indicate the potential for combined transcatheter aortic root and mitral valve replacement in treating aortic root pathologies. In future, in vivo studies are expected to validate this approach and ascertain its durability.

Transcatheter mitral valve interventions: pre-procedural planning and intra-procedural guidance

Mitral regurgitation is the most prevalent valve disease worldwide. Percutaneous mitral valve interventions are emerging as alternative options for high-risk patients with severe mitral regurgitation not eligible for conventional surgery. Accurate patient selection is based on a detailed pre-procedural multimodality imaging evaluation. Morphology and functional anatomy of the mitral valve should be evaluated to determine the feasibility of treatments and to identify the best therapeutic approach. The procedures are guided by fluoroscopy, transoesophageal echocardiography and fusion imaging, ensuring a continuous communication between the interventionalist and the imaging specialist. The present review will cover the pre-procedural planning and the intra-procedural guidance of the most used transcatheter approaches in the setting of native mitral valve regurgitation: edge to edge repair, percutaneous direct and indirect annuloplasty, transapical beating-heart chordal implantation and transcatheter mitral valve replacement.

Centre procedural volume and adverse in-hospital outcomes in patients undergoing percutaneous transvenous edge-to-edge mitral valve repair using MitraClip® in Germany

AIMS

The number of transcatheter mitral valve repair (TMVr) procedures has increased substantially during the last years. A better understanding of the relationship between hospital volume of transcatheter transvenous mitral valve repairs using MitraClip® and patient outcomes may provide information for future policy decisions to improve patient management.

METHODS AND RESULTS

We analysed patient characteristics and in-hospital outcomes for all TMVr procedures using MitraClip® performed in Germany from 2011 to 2017. Hospitals were stratified according to centre volumes and patients were compared for baseline characteristics and adverse in-hospital events. Overall, 24 709 inpatients were treated during the observational period. Patients treated in centres with a volume of ≤10 procedures annually developed more often pulmonary embolism (odds ratio 2.22, 95% confidence interval 1.19-4.13; P = 0.012) compared to those treated in centres with a volume of >10 procedures annually, whereas no association of centre volume (≤10 or >10) was found with in-hospital mortality (P = 0.728). Although patients treated in centres with an annual volume >25 TMVr procedures had higher numbers of comorbidities compared to those treated in centres with an annual volume of ≤25 TMVr procedures, in-hospital mortality did not differ (3.6% vs. 3.5%, P = 0.485). Similarly, when centre volumes were stratified for ≤50 vs. >50 procedural volumes, no association with in-hospital mortality was recorded (P = 0.792). A lower rate of mitral valve surgery after MitraClip® was observed over time, particularly in high-volume centres.

CONCLUSION

Annual numbers of MitraClip® implantations increased from 2011 to 2017 in Germany, whereas in-hospital mortality remained stable. Although patients treated in high-volume centres had a more unfavourable risk profile, in-hospital mortality was comparable to that of low-volume centres.

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.