Pretranscatheter and Posttranscatheter Valve Planning with Computed Tomography

The range of potential transcatheter solutions to valve disease is increasing, bringing treatment options to those in whom surgery confers prohibitively high risk. As the range of devices and their indications grow, so too will the demand for procedural planning. Computed tomography will continue to enable this growth through the provision of accurate device sizing and procedural risk assessment.

Orthotopic Transcatheter Mitral Valve Replacement

Mitral valve dysfunction is prevalent amongst older patients. Of those not suitable for surgical therapy, mitral transcatheter edge-to-edge repair (TEER) can treat as large proportion of patients, many are not suitable TEER candidates. As such, orthotopic transcatheter mitral valve replacement (TMVR) is an important innovation but it faces significant challenges. Orthotopic TMVR requires a prosthesis with stable anchoring, adequate sealing, minimal footprint in the left ventricle and long term durability. Multidisciplinary expertise in advanced imaging, surgery, heart failure are needed for success.

Left Ventricular Outflow Tract Modification for Transcatheter Mitral Valve Replacement

Left ventricular outflow tract (LVOT) obstruction is a life-threatening complication of transcatheter mitral valve replacement. In-depth analysis of pre-procedural computed tomography enables accurate prediction of this risk. Several techniques for LVOT modification, including Laceration of the Anterior Mitral leaflet to Prevent Outflow ObtructioN, preemptive alcohol septal ablation, preemptive radiofrequency ablation, and Septal Scoring Along the Midline Endocardium, have been described as effective strategies to mitigate this risk. This review aims to explore the indications, procedural steps, and outcomes associated with these LVOT modification techniques.

Postsurgical Transcatheter Mitral Valve Replacement

Reintervention is commonly required postsurgical mitral valve replacement (SMVR) or repair due to bioprosthetic valve and annuloplasty ring degeneration. However, redo SMVR is associated with a high risk of morbidity and mortality. Postsurgical transcatheter mitral valve replacement (TMVR) is a safe and less-invasive alternative that has repeatedly been shown to be associated with improved survival and lower rates of complications compared with redo SMVR. Comprehensive patient evaluation and thorough procedural planning are key to successful TMVR.

Management strategies and prognosis of patients ineligible for transcatheter mitral valve replacement

BACKGROUND

Transcatheter mitral valve replacement (TMVR) faces anatomical challenges, currently limiting widespread adoption.

OBJECTIVES

To describe the natural history and prognosis of patients ineligible for various TMVR devices.

METHODS

During a 4-year period (2019-2023) 3 TMVR devices (SAPIEN M3, Intrepid and Alta Valve) became available at a single institution (The Christ Hospital, Cincinnati, OH) in the setting of pivotal clinical trials or early feasibility study. Consenting patients who were deemed ineligible ≥1 of these trials were prospectively studied to capture anatomical reasons for ineligibility, cross-over to alternative mitral valve therapies (surgery or high-risk mitral transcatheter edge to edge repair [M-TEER]), and clinical events.

RESULTS

A total of 61 patients (out of 71 consenting patients or 85.9 %) were deemed ineligible for TMVR during the study period. The mean age was 79.2 ± 8.8 years, 65.6 % were female, with elevated surgical risk (median STS 4.3, IQR: 2.7-7.3). The 2 most common anatomical reasons for ineligibility were increased risk of left ventricular outflow tract obstruction (LVOTO) (n = 24, 39.3 %) and annular size (n = 29, 47.5 %). During follow-up (median 277 [162-555] days) there were 7 deaths (11.5 %) and 12 (19.7 %) hospitalizations for heart failure. Management strategies included high-risk M-TEER in 11 patients (1 death [9.0 %], 0 HF hospitalizations [0 %]), surgery in 9 patients (0 deaths, 1 HF hospitalizations [11.1 %]), and medical management in 41 patients (6 deaths [14.6 %], 11 HF hospitalizations [26.8 %]) (p = 0.715 for mortality and p = 0.093 for HF hospitalizations). Residual MR ≥ moderate was 0 %, 50 %, and 100 % for surgery, M-TEER and medical treatment, respectively (p < 0.001).

CONCLUSIONS

One third of patients deemed ineligible for TMVR are candidates for high-risk M-TEER or surgery with acceptable morbidity and mortality. Our results have practical implications for patient management.

Antithrombotic Treatment After Transcatheter Valve Interventions: Current Status and Future Directions

PURPOSE

The optimal antithrombotic strategy after transcatheter valve interventions is a subject of ongoing debate. Although there is evidence from randomized trials in patients undergoing transcatheter aortic valve replacement (TAVR), current evidence on optimal antithrombotic management after transcatheter mitral or tricuspid valve interventions is sparse. This article appraises the current evidence on this topic.

METHODS

This narrative review presents key research findings and guideline recommendations, as well as highlights areas for future research.

FINDINGS

After TAVR, randomized trial evidence suggests that single antiplatelet therapy is reasonable for patients without pre-existing indications for oral anticoagulation (OAC). If there is a concurrent indication for OAC, the addition of antiplatelet therapy increases bleeding risk. Whether direct oral anticoagulants achieve better outcomes than vitamin K antagonists is uncertain in this setting. Although OAC has been shown to reduce subclinical leaflet thrombosis (which may progress to structural valve degeneration), bleeding events are unacceptably high. There is a lack of randomized trial data comparing antithrombotic strategies after transcatheter mitral or tricuspid valve replacement or after mitral or tricuspid transcatheter edge-to-edge repair. Single antiplatelet therapy after mitral or tricuspid transcatheter edge-to-edge repair may be appropriate, whereas at least 3 months of OAC is suggested after transcatheter mitral valve replacement or transcatheter tricuspid valve replacement.

IMPLICATIONS

Randomized studies are warranted to address the knowledge gaps in antithrombotic therapy after transcatheter valve interventions and to optimize outcomes.

Secondary retensioning of a tether-based device for transapical transcatheter mitral valve implantation

OBJECTIVES

Relevant paravalvular leakage (PVL) due to prosthesis dislodgement is a rare but potentially severe complication after transcatheter mitral valve implantation (TMVI). Due to the epicardial anchoring mechanism of the Tendyne® TMVI system, repositioning of the valve stent may be possible by retensioning of the tether. This multicentre study aimed to investigate the procedural and short-term safety as well as efficacy of retensioning manoeuvres.

METHODS

From 2017 to 2021, N = 18 patients who underwent secondary tether retensioning were identified. Baseline, procedural and follow-up data were available from N = 11 patients and analysed according to the Mitral Valve Research Consortium definitions. Continuous variables are shown as median with interquartile range.

RESULTS

All patients [age 75 years (73.5, 85.0), 64% male (N = 7), EuroSCORE II 6.2% (5.8, 11.6)] presented with post-procedural PVL [63.6% (N = 7) with PVL ≥3+]. Of these, 54% (N = 6) showed signs of haemolysis. The majority were severely symptomatic [New York Heart Association ≥III (91%, N = 10)]. Procedural outcomes revealed no acute complications and no mortality. At discharge, PVL was completely eliminated in 91% (N = 10) of patients with 1 case of remaining moderate PVL. At 30 days, Mitral Valve Research Consortium device success was achieved in 82% (N = 9) of patients. Two patients required open surgical mitral valve replacement due to persistent and recurrent PVL. In 89% (N = 8) of patients with successful retensioning procedure, New York Heart Association class was I/II. There was no 30-day mortality.

CONCLUSIONS

This multicentre study demonstrates technical feasibility, procedural safety and acute efficacy of retensioning procedures in the majority of patients. The potential to retension the tether in transapical TMVI may provide additional management advantages in populations at high surgical risk.

Characteristics and outcomes of patients undergoing transcatheter mitral valve replacement with the Tendyne system

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has emerged as alternative to transcatheter edge-to-edge repair (TEER) for treatment of mitral regurgitation (MR); however, the role of TMVR with the Tendyne system among established treatments of MR is not well defined. We assessed characteristics and outcomes of patients treated with the Tendyne system in the current clinical practice.

METHODS

We reviewed patients who underwent cardiac computed tomography and were judged eligible for the Tendyne system.

RESULTS

A total of 63 patients were eligible for TMVR with the Tendyne system. Of these, 17 patients underwent TMVR, and 46 were treated by TEER. Patients treated with the Tendyne system were more likely to have a high transmitral pressure gradient and unsuitable mitral valve morphology for TEER than those treated with TEER. TMVR with the Tendyne system reduced the severity of MR to less than 1 + in 94.1% of the patients at discharge and achieved a greater reduction in left ventricular (LV) end-diastolic volume at the 30-day follow-up compared with TEER. In contrast, patients treated with the Tendyne system had a higher 30-day mortality than those treated with TEER, while the mortality between 30 days and one year was comparable between Tendyne and TEER.

CONCLUSIONS

Among patients eligible for the Tendyne system, approximately a quarter of the patients underwent TMVR with the Tendyne system, which led substantial reduction of MR and LV reverse remodeling than TEER. In contrast, the 30-day mortality rate was higher after TMVR with the Tendyne compared to TEER.

Transcatheter mitral valve implantation with Tendyne System Ten Years since the First In-Human Implant A systematic review

BACKGROUND

Transcatheter mitral valve replacement (TMVR) using the Tendyne™ valve is regarded as one of the most studied TMVR systems. The first human experience with the procedure was reported in 2013. The present study aims to systemically revise the published literature to document the global experience with TMVR using the Tendyne™ valve.

METHODS

The present review was conducted in line with the PRISMA statement on systematic reviews. Database included in the search process were Scopus, Web of Science and Pubmed. Search was processed using multiple keywords combinations and was adjusted to English literature only.

RESULTS

We included 26 articles in the final analysis reporting data from 319 patients. Patients recruited by the included studies comprised 192 males (60.2%) and 127 females (39.8%). In the studied patients, mitral annular calcification (MAC) was reported in 107 patients (33.5%). Preoperatively, MR grades 1,2 and 3-4 were reported in 3,5 and 307 patients respectively. Postoperatively, MR grades 1, 2 and 4 were reported in only 12, 3 and 1 patients respectively. Technical success was achieved in 309 patients (96.9%). Follow up durations widely varied among different studies from just days before discharge to 6 years. At the end of follow up, 79 patients died (24.8%) including 52 patients (16.3%) due to cardiovascular causes.

CONCLUSIONS

Management of mitral valve disease using the Tendyne system appears to be a promising minimally invasive option for many high-risk patients with accepted procedural feasibility and safety profile.

Transcatheter mitral valve implantation using the Tendyne valve in a patient with prior transcatheter aortic valve implantation: a case report

Background

The presence of aortic and mitral disease in a patient who is not a suitable candidate for surgical correction poses significant challenges in the diagnostic workup as well as management plans. Percutaneous treatment can be staged to fix the aortic valve with transcatheter aortic valve implantation (TAVI) as a first step, followed by reassessment and percutaneous correction of mitral regurgitation (MR).

Case summary

A 65-year-old female with multiple co-morbidities presented with acute coronary syndrome and heart failure. She was diagnosed with three-vessel coronary artery disease and degenerative low-flow low-gradient severe aortic stenosis, along with severe degenerative MR with a left ventricular ejection fraction of 35%. Because of the high surgical risk, she underwent multi-vessel percutaneous coronary intervention with stenting. Transcatheter aortic valve implantation was done as a staged procedure, which partially improved her symptoms. Mitral regurgitation was not suitable for percutaneous mitral valve edge-to-edge repair. After a discussion by the heart team, she underwent transcatheter mitral valve implantation, for which the Tendyne mitral valve (Tendyne™; Abbott) was used through a transapical approach. There was no paravalvular leak, and the mean gradient across the valve was 2 mmHg. She was symptomatically better at follow-up and an echocardiogram showed a normally functioning aortic valve and Tendyne mitral valves.

Discussion

Transapical transcatheter mitral valve implantation using the Tendyne valve is a feasible option for patients with prior TAVI. This can be considered an alternative treatment for MR in patients who are not suitable for edge-to-edge mitral repair.

Transcatheter mitral valve replacement to treat severe calcified rheumatic native mitral stenosis: role of three-dimensional printing-a case report

Background

Rheumatic heart disease is a major disease that seriously affects human health and survival worldwide. Rheumatic mitral stenosis often has relatively complex pathological changes, and its progression leads to various manifestations of mitral valve dysfunction and adverse clinical events.

Case summary

We present a 60-year-old patient who developed chest tightness, shortness of breath, and bilateral lower limb oedema in 2018 (New York Heart Association functional class III). Systolic and diastolic murmurs could be heard in the mitral auscultation area. In December 2021, the patient was admitted to the hospital with stroke. Thereafter, transthoracic echocardiography and computed tomography were performed, and the progress of rheumatic mitral stenosis was recorded. Due to the patient's high surgical risk, a patient-specific three-dimensional printed model was used to observe anatomical structures and simulate main procedures, and the surgeons finally chose to perform transcatheter mitral valve replacement. The balloon-expandable bioprothesis was released from the right femoral artery to treat the rheumatic mitral stenosis. The patient remained asymptomatic at the 6-month follow-up.

Discussion

For patients with rheumatic mitral stenosis with high surgical risk, it is feasible to conduct transcatheter mitral valve replacement under the guidance of three-dimensional printing.

A valve embolized twice: a case report of Sapien 3 embolization in left ventricle and left atrium during transcatheter transapical mitral valve-in-valve implantations for a failed bioprosthesis

Background

Transcatheter mitral valve-in-valve (TMVIV) using the Sapien 3 (Edwards Lifesciences, Irvine, CA, USA) transcatheter heart valve is associated with high technical success and sustained valve performance. However, complications may occur or be detected during or after the procedure.

Case summary

We herein describe a rare case of a 59-year-old female who underwent TMVIV for a failed surgical mitral bioprosthesis. During the procedure, the device was embolized twice into the left ventricle and left atrium, respectively, resulting from the crimped transcatheter valve partially detaching from the balloon of the Certitude delivery system during passage through a tight transapical sheath. Fortunately, we were able to catch the dislodged valve and anchor it by the partially inflated device balloon, followed by successful repositioning and deployment.

Discussion

In cases where the valve has already detached, as in the present case, the sheath may be advanced against the proximal end of the valve as a pusher, providing good support to push the entire system to cross the bioprosthesis. Then, the delivery catheter should be withdrawn with the counteraction of the sheath in order to correct the interrelated positions of the valve and the balloon. Finally, the valve can be positioned and deployed after the sheath is withdrawn.

Anatomic considerations after commando double valve reconstruction: insights for future valve-in-valve therapies

OBJECTIVES

The Commando technique for reconstruction of the aortomitral intervalvular fibrous body is effective to facilitate double valve surgery in cases of endocarditis or infiltrative calcification. The length of patch utilized in reconstruction of the intervalvular fibrous body has an important relationship to the geometry of the mitral valve (MV) and aortic valve (AV) and may impact on potential future valve-in-valve (VIV) therapy. Here we report anatomic measurements after Commando reconstruction in a small group of patients and analyse the impact of reconstruction techniques on transcatheter VIV therapies.

METHODS

Seven patients from January 2018 to April 2022 who underwent double valve surgery with the Commando technique with postoperative computed tomography (CT) scans were identified. Computed tomographic reconstruction of the AV and MV was performed using 3mensio software and virtual transcatheter valve replacement was performed. Two of these patients who had preoperative imaging was analysed to assess the change in aortomitral geometry resulting from reconstruction.

RESULTS

Measurements for each patient post-reconstruction are given in the table. Aortomitral length was grossly inversely proportional to aortomitral angle (AMA). AMA and aortomitral curtain (AMC) length were significantly altered post-Commando in 2 analysed patients with pre- and postoperative computed tomography scan. Transcatheter AV and MV replacements were feasible in all patients post-Commando. The AMA was larger and more favorable for mitral VIV in patients in which the AMC was short.

CONCLUSIONS

AMC length, as determined by location of AV annular sutures, may be an important consideration in surgical decision-making for VIV after the Commando procedure.

Secondary Mitral Regurgitation and Heart Failure: Current Advances in Diagnosis and Management

The causes of mitral regurgitation (MR) can be broadly divided into primary and secondary causes. Although primary MR is caused by degenerative alterations of the mitral valve and the mitral valve apparatus, secondary (functional) MR is multifactorial and related to dilation of the left ventricle and/or mitral annulus commonly resulting in concomitant restriction of the leaflets. Therefore, the treatment of secondary MR (SMR) is complex and includes guideline directed heart failure therapy along with surgical and transcatheter approaches that have shown effectiveness in certain subgroups. This review aims to provide insight into current advances in diagnosis and management of SMR.

Post-procedural structural heart CT imaging: TAVR, TMVR, and other interventions

Transcatheter valve replacement has experienced substantial growth in the past decade and this technique can now be used for any of the four heart valves. Transcatheter aortic valve replacement (TAVR) has overtaken surgical aortic valve replacement. Transcatheter mitral valve replacement (TMVR) is often performed in pre-existing valves or after prior valve repair, although numerous devices are undergoing trials for replacement of native valves. Transcatheter tricuspid valve replacement (TTVR) is similarly under active development. Lastly, transcatheter pulmonic valve replacement (TPVR) is most often used for revision treatment of congenital heart disease. Given the growth of these techniques, radiologists are increasingly called upon to interpret post-procedural imaging for these patients, particularly with CT. These cases will often arise unexpectedly and require detailed knowledge of potential post-procedural appearances. We review both normal and abnormal post-procedural findings on CT. Certain complications-device migration or embolization, paravalvular leak, or leaflet thrombosis-can occur after replacement of any valve. Other complications are specific to each type of valve, including coronary artery occlusion after TAVR, coronary artery compression after TPVR, or left ventricular outflow tract obstruction after TMVR. Finally, we review access-related complications, which are of particular concern due to the requirement of large-bore catheters for these procedures.

Transcatheter mitral valve replacement or repair for secondary mitral regurgitation: a propensity score-matched analysis

AIMS

This study aimed to compare outcomes after transcatheter mitral valve replacement (TMVR) and mitral valve transcatheter edge-to-edge repair (M-TEER) for the treatment of secondary mitral regurgitation (SMR).

METHODS AND RESULTS

The CHOICE-MI registry included 262 patients with SMR treated with TMVR between 2014 and 2022. The EuroSMR registry included 1065 patients with SMR treated with M-TEER between 2014 and 2019. Propensity score (PS) matching was performed for 12 demographic, clinical and echocardiographic parameters. Echocardiographic, functional and clinical outcomes out to 1 year were compared in the matched cohorts. After PS matching, 235 TMVR patients (75.5 years [70.0, 80.0], 60.2% male, EuroSCORE II 6.3% [interquartile range 3.8, 12.4]) were compared to 411 M-TEER patients (76.7 years [70.1, 80.5], 59.0% male, EuroSCORE II 6.7% [3.9, 12.4]). All-cause mortality was 6.8% after TMVR and 3.8% after M-TEER at 30 days (p = 0.11), and 25.8% after TMVR and 18.9% after M-TEER at 1 year (p = 0.056). No differences in mortality after 1 year were found between both groups in a 30-day landmark analysis (TMVR: 20.4%, M-TEER: 15.8%, p = 0.21). Compared to M-TEER, TMVR resulted in more effective mitral regurgitation (MR) reduction (residual MR ≤1+ at discharge for TMVR vs. M-TEER: 95.8% vs. 68.8%, p < 0.001), and superior symptomatic improvement (New York Heart Association class ≤II at 1 year: 77.8% vs. 64.3%, p = 0.015).

CONCLUSION

In this PS-matched comparison between TMVR and M-TEER in patients with severe SMR, TMVR was associated with superior reduction of MR and superior symptomatic improvement. While post-procedural mortality tended to be higher after TMVR, no significant differences in mortality were found beyond 30 days.

Transcatheter Mitral Valve Repair Versus Transcatheter Mitral Valve Replacement in Patients with Mitral insufficiency

AIMS

Mitral regurgitation (MR) is the most prevalent form of valvular heart disease. Transcatheter mitral valve repair (TMVr) and transcatheter mitral valve replacement (TMVR) have recently emerged as alternatives to open heart surgical repair or replacement. However, studies on the comparative outcomes of TMVr and TMVR are limited. This study aims to compare the demographics, complications and outcomes of TMVr and TMVR based on a real-world investigation of the National Inpatient Sample (NIS) database.

METHODS AND RESULTS

From 2016-2018 in the NIS database, a total of 210 and 3370 patients who underwent TMVR and TMVr, respectively, were selected. The mean age of the patients was 75.99 years (TMVr) and 69.6 years (TMVR) (p <0.01). The mortality of patients who received TMVR was higher compared to that of patients who were treated with TMVr (8.1 vs. 1.9%, p <0.01). The patients who underwent TMVR were more likely to suffer perioperative complications including blood transfusions (16.2 vs. 5.0%, p <0.01) and acute kidney injury (22.9 vs. 13.3%, p <0.01). The average cost of treatment was higher (USD $278864 vs. USD $216845, p <0.01), and the average duration of hospitalization was longer (8.73 vs. 4.17 d, p <0.01) for TMVR compared to TMVr. When taking into account perioperative comorbidities and other factors, TMVR was associated with a worse adjusted in-hospital mortality (odds ratio [OR], 3.307 [95% CI, 1.533-7.136]; p <0.01).

CONCLUSION

TMVr is associated with lower mortality, peri-procedural morbidity, and resource use compared to TMVR. A patient-centered approach can help guide decision-making about the choice of intervention for the individual patient and more studies evaluating the long-term outcomes and durability of TMVR are needed at present.

Management of life-threatening deformation of obstructive transcatheter mitral valve replacement bioprosthesis with balloon inflation in left ventricular outflow tract: a case report

Background

Left ventricular outflow track (LVOT) obstruction (LVOTO) is a severe complication of transcatheter mitral valve replacement (TMVR) procedures, with an uncertain prognosis and only few strategies available to prevent its occurrence. TMVR is thus contraindicated in some patients because of a high risk of LVOTO onset. We demonstrate how LVOTO can be managed with a balloon inflation in the LVOT and a D-shaped deformation of the bioprosthetic valve.

Case summary

A 64-year-old female presented with acute pulmonary oedema 2 weeks following aortic valve replacement and aorto-coronary bypass surgeries. A concomitant mitral stenosis, secondary to significant calcifications of the mitral annulus, was not treated during the procedure. After surgery, the mitral valvulopathy caused an acute heart failure and TMVR was performed by the heart team. The procedure was complicated by a cardiac arrest secondary to the onset of LVOTO which was managed by a balloon inflation in the LVOT and an alcohol septal ablation. Two-year follow-up shows a favourable outcome of the patient and good function of the prosthetic valve despite its deformation.

Discussion

This case highlights the successful management of a LVOTO following valve-in-mitral annular calcification TMVR by balloon inflation in the LVOT. It is strongly recommended to place a 'rescue' guidewire in transaortic position during TMVR in order to manage the potential onset of acute LVOTO.

Preoperative planning using virtual reality for percutaneous transseptal valve-in-valve transcatheter mitral valve replacement: a case report

Background

Virtual reality (VR) technology has been implemented as a pre-procedural planning tool for cardiovascular interventions to enable detailed evaluation of patient anatomy from different vantage points. Here, we employed a VR platform to preoperatively plan for percutaneous valve-in-valve transcatheter mitral replacement (ViV-TMVR) in a prohibitive surgical candidate.

Case summary

An 85-year-old male with a history of two prior sternotomies for bioprosthetic aortic valve (AV) and mitral valve (MV) 31 mm Medtronic Mosaic bioprosthesis presented with severe mitral regurgitation from a degenerative bioprosthetic MV. The patient was deemed a prohibitive surgical candidate for a third sternotomy and instead was recommended a percutaneous transseptal ViV-TMVR. An electrocardiogram-gated chest computed tomography (CT) provided a neo-left-ventricular outflow tract (neo-LVOT) of 1.89 cm². This CT was reconstructed to create a 360° VR (360VR) model. A 29 mm SAPIEN three bioprosthetic valve, selected based on the already implanted MV, was placed inside the bioprosthetic MV and analysed in VR at different angles to ensure it would not obstruct the LVOT. The neo-LVOT measured in VR was 3.02 cm², which would allow for sufficient blood flow without significant obstruction from the new SAPIEN three bioprosthetic valve. The patient tolerated the procedure well.

Discussion

This case demonstrates the utility of VR as a pre-procedural planning tool for interventional cardiology procedures. Preoperative planning in VR alleviated concerns regarding obstruction of the neo-LVOT and helped confirm safe implantation by clearly showing the three-dimensional spatial relationship between the implants and surrounding patient anatomy.

Transcatheter Mitral Valve Replacement in Failed Bioprosthetic Surgical Valves and Surgical Annuloplasty Rings

PURPOSE OF REVIEW

Repeat surgery for failed mitral valve prostheses and repairs are fraught with high rates of morbidity and mortality. Therefore, clinicians have evolved transcatheter technology as an alternative therapy. This review serves as an update as the field has moved out of the early learning curve of treating postsurgical mitral valve failures.

RECENT FINDINGS

Mitral valve-in-valve procedures have higher rates of technical success and better in-hospital and 1-year mortality rates than mitral valve-in-ring cases. The higher rates of complications, including left ventricular outflow tract obstruction, paravalvular leak, valve embolization, and need for a 2nd valve, may explain these outcomes. Mitral valve-in-ring procedures have attenuated outcomes as compared to valve-in-valve. Clinicians should be cognizant of the nuanced complexities and the potential for suboptimal outcomes in using balloon-expandable valves for mitral valve-in-ring procedures.

Image-Guided Targeted Mitral Valve Tethering with Chordal Encircling Snares as a Preclinical Model of Secondary Mitral Regurgitation

Development of transcatheter mitral valve interventions has ushered a significant need for large animal models of secondary mitral regurgitation. Though currently used heart failure models that chronically develop secondary mitral regurgitation are viable, the severity is lower than patients, the incubation time is long, and mortality is high. We sought to develop a swine model of acute secondary mitral regurgitation that uses image-guided placement of snares around the mitral chordae. Twenty-seven adult swine (n = 27) were assigned to secondary mitral regurgitation induced by valve tethering with image-guided chordal encircling snares (group 1, n = 7, tether MR (tMR)); secondary mitral regurgitation by percutaneous posterolateral myocardial infarction causing ventricular dysfunction and regurgitation (group 2, n = 6, functional MR (fMR)); and control animals (group 3, n = 14). Regurgitant fraction in tMR was 42.1 ± 14.2%, in fMR was 22 ± 9.6%, and in controls was 5.3 ± 3.8%. Mitral tenting height was 9.6 ± 1.3 mm in tMR, 10.1 ± 1.5 mm in fMR, and 5.8 ± 1.2 mm in controls. Chordal encircling tethers reproducibly induce clinically relevant levels of secondary mitral regurgitation, providing a new animal model for use in translational research.

Transcatheter mitral valve interventions

While there are dozens of novel transcatheter mitral devices in various stages of development, they remain years away from FDA approval. The existing approved transcatheter mitral interventions-transcatheter edge to edge repair for primary and secondary mitral regurgitations and transcatheter mitral valve-in-valve and valve-in-ring procedures for failing surgical prostheses-have seen a marked increase in both use and published data over the past several years. Transcatheter edge to edge repair with MitraClip has revolutionized the management of functional mitral regurgitation in heart failure with demonstrated reductions in mortality and heart failure hospitalization and is an appropriate option for patients with primary mitral regurgitation at high or prohibitive surgical risk. In patients with failing surgical mitral prostheses transcatheter mitral valve-in-valve and valve-in-ring procedures are an appealing alternative to repeat mitral valve surgery. Existing data and relevant concerns for these procedures are discussed herein.

Mitral Valve Annuloplasty Failure and Percutaneous Treatment Options

PURPOSE OF REVIEW

Mitral valve repair is a common surgical procedure for both primary and secondary mitral regurgitation. With operations performed earlier in disease progression and increased patient longevity, the need for a repeat intervention is not infrequent. With the associated risks of reoperation and patient comorbidities, percutaneous techniques for acute or delayed failure after ring annuloplasty are emerging.

RECENT FINDINGS

Current commercially available devices, used in "off-label" ways, such as the MitraClip, may be effective in repairing recurrent mitral regurgitation after annuloplasty. Similarly, a valve-in-ring transcatheter mitral valve replacement can be considered in patients at high risk for surgical reoperation. These procedures are not without risk, for example, resultant mitral stenosis in the setting of edge-to-edge repair or left ventricular outflow tract (LVOT) obstruction with valve-in-ring transcatheter mitral valve replacement. Newer devices are emerging to permit more options for this subset of patients, which include transcatheter valves that are specifically designed for the mitral position. Undoubtedly, surgical reoperation has increased risk as compared to primary operation. Though percutaneous options are evolving, use in this patient population is currently limited to "off-label" use and is also associated with procedural complexities and risk. It is prudent for cardiologists, surgeons, and anesthesiologists to weigh risks, benefits, and limitations when considering patients for surgical reoperation, percutaneous repair, or transcatheter replacement after failed mitral annuloplasty.

Transcatheter therapies for secondary mitral regurgitation in advanced heart failure: what are we aiming for?

A severe secondary mitral regurgitation (SMR) can be found in a significant portion of patients affected by advanced heart failure (AHF). Conventional therapies (optimal medical therapy, devices, surgery) present restricted clinical efficacy in this stage of the left ventricle disease which is burdened by high mortality and morbidity rates. Although the treatment of choice is represented by heart transplantation (HTx), there is an unmet need related to the limited supply of donor hearts (as opposed to the growing prevalence of AHF) and the low eligibility of highly symptomatic patients. In case of concomitant severe SMR, transcatheter mitral valve therapies (repair and replacement) may play a crucial role in this setting. While a direct prognostic improvement after correction of SMR has yet to be proved, AHF patients can benefit from the following: hemodynamic stabilization, symptomatic relief, normalization of pulmonary arterial pressures, and reduction in hospitalizations for acute heart failure. Obtaining these results may lead to the clinical consequences of reaching the HTx in good enough clinical status (bridge to heart transplantation), becoming eligible for the HTx (bridge to HTx candidacy), and being delisted for clinical improvement (bridge to recovery). Therefore, achieving traditional secondary endpoints in patients with AHF and SMR can translate into significant clinical implications.

Transcatheter mitral valve replacement: tissue in-growth after 4 weeks

OBJECTIVES

Tissue reaction to transcatheter mitral valve replacement in the mitral annulus remains to be elucidated.

METHODS

Trileaflet porcine pericardial valves were sewn onto self-expanding d-shaped nitinol stents, which were delivered transapically and in an off-pump fashion into the mitral position of 10 pigs. After at least 4 weeks of follow-up, gross pathological assessment and histological examination were performed. The specimens were stained with Movat's pentachrome, Elastica-van-Gieson and von Kossa staining. The leucocytes, B cells, T cells or macrophages were detected by specific immunohistochemical staining.

RESULTS

Proper stent positioning in the mitral annulus was achieved in 9/10 animals. Nine of 10 animals survived the desired observation period. In all but one, the mitral valve stent was well integrated into the left atrium and perpendicularly embedded into the annulus by 85 ± 24%. One animal had minor fractures in the nitinol struts and another animal showed tearing of 1 of 4 tethers. Histological examination demonstrated no major tissue reaction with the nitninol struts but well-preserved overall structures around the mitral annulus in 8/9 cases.

CONCLUSIONS

This is the first report demonstrating good in-growth of transcatheter-delivered anatomically shaped mitral valve stents after at least 4 weeks of follow-up. Histological examination demonstrated progressive healing and neointimalization.

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.

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.

Unusual Cause of Left Ventricular Outflow Tract Obstruction Following Transcatheter Mitral Valve-in-Ring Replacement

•Causes of LVOT obstruction after transcatheter mitral valve-in-ring replacement. •Unusual cause contributing to obstruction in this case. •Importance of procedural planning to predict and minimize risk for LVOT obstruction. •Role of TEE in diagnosis and in directing therapy when this complication occurs. •Role of noninvasive techniques to prevent and treat LVOT obstruction.

New stent for transapical mitral valve replacement in acute swine experiment

Background

Many patients with mitral regurgitation are denied open-heart surgery due to perceived high risk. Transcatheter mitral valve replacement is a therapeutic alternative for patients at high surgical risk. This study aimed to assess the feasibility of a new self-expanding valved stent for transcatheter mitral valve replacement via apex in an acute animal model.

Methods

Eight porcine experiments were performed in the acute study. A left thoracotomy was performed, and the new self-expanding transcatheter valved stent was deployed under fluoroscopic guidance in the native mitral annulus via apex. Hemodynamic data were recorded before and after implantation. Mitral annulus diameter and valve area were measured using echocardiography. Transvalvular and left ventricular outflow tract pressure gradients were measured using invasive methods.

Results

Seven animals underwent successful transapical mitral valve replacement; the implantation was unsuccessful in one animal. The mean procedure time, defined from placement to tightening of the purse-string suture, was 17.14 ± 7.86 min. Hemodynamic data before and after transapical mitral valve replacement showed no difference in statistical analysis. The mean diameter of the self-expanding device after implantation was 2.58 ± 1.04 cm; the mean functional area was 2.70 ± 0.26 cm². Trace-to-mild central and paravalvular leaks were detected in 7 valves. The mean pressure gradient across the self-expanding device was 2.00 ± 0.82 mmHg; the corresponding gradient across the LVOT was 3.28 ± 1.11 mmHg. Postmortem evaluation confirmed precise device positioning in 7 animals with no signs of LVOT obstruction.

Conclusion

Transcatheter mitral replacement of the new valved stent was confirmed feasible in acute preclinical models. The new stent reveals optimal design parameters.

Current and Future Application of Transcatheter Mitral Valve Replacement

Mitral valve anatomy is complex, and one size does not fit all. More recently, percutaneous mitral valve interventions have revolutionized the management of primary and secondary mitral regurgitation (MR). However, edge-to-edge leaflet repair is not suitable for a large proportion of individuals including those with a failing bioprosthetic mitral valve/annuloplasty ring, and patients with significant mitral annular calcification resulting in mixed mitral valve disease/mitral stenosis. For this high risk cohort, transcatheter mitral valve replacement seems to be an attractive alternative.

A Simplified In Silico Model of Left Ventricular Outflow in Patients After Transcatheter Mitral Valve Replacement with Anterior Leaflet Laceration

In silico modeling has been proposed as a tool to simulate left ventricular (LV) outflow tract (LVOT) obstruction in patients undergoing transcatheter mitral valve replacement (TMVR). This study validated a simplified approach to simulate LV outflow hemodynamics in the setting of TMVR with anterior leaflet laceration, a clinical technique used to mitigate the risk of LVOT obstruction. Personalized, 3-dimensional computational fluid dynamics models were developed from computed tomography images of six patients who underwent TMVR with anterior leaflet laceration. LV outflow hemodynamics were simulated using the patient-specific anatomy and the peak systolic flow rate as boundary conditions. The peak outflow velocity, a clinically relevant hemodynamic metric, was extracted from each simulation (v_sim-peak) and compared with the clinical measurement from Doppler echocardiography (v_clin-peak) for validation. In silico models were successfully developed and implemented for all patients. The pre-processing time was 2 h per model and the simulation could be completed within 3 h. In three patients, the lacerated anterior leaflet exposed open cells of the transcatheter valve to flow. Good agreement was obtained between v_sim-peak and v_clin-peak (r = 0.97, p < 0.01) with average discrepancies of 5 ± 2% and 14 ± 1% for patients with exposed and unexposed cells of the transcatheter valve, respectively. The proposed in silico modeling paradigm therefore simulated LV outflow hemodynamics in a time-efficient manner and demonstrated good agreement with clinical measurements. Future studies should investigate the ability of this paradigm to support clinical applications.

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.

Debate - Replacement of the Mitral Valve Under One Year of Age: Mechanical Valves Should Be Used

This article reviews the literature, focusing on publications from the third millennium and the results of mitral valve replacement in children younger than 1 year of age. Special consideration has been given to neonatal and infant valve replacement to provide insights into valve choice and technique. Mitral valve replacement is an important topic because it carries the highest mortality and poorer long-term prognosis than any other valve replacement in children.

Transcatheter mitral valve replacement

Transcatheter mitral valve (MV) repair, specifically the edge-to-edge leaflet repair, is a less invasive treatment of symptomatic mitral regurgitation (MR) in patients with high or prohibitive surgical risk. In cases with severe leaflet calcification, small mitral orifice area, and/or extremely wide regurgitation across the entire MV commissure, transcatheter MV repair may rather cause suboptimal or potentially hazardous outcomes. In these cases, MV replacement can be a more suitable option. Recently, percutaneous transcatheter MV replacement has emerged as an acceptable therapeutic option for the treatment of degenerated surgical bioprosthetic disease. Moreover, several transcatheter devices for native MV replacement are under evaluation with a hope to provide more complete and reproducible restoration of MV function. In this article, we will review current status, applications, clinical outcomes, and limitations that need to be overcome for transcatheter MV replacement for both degenerated surgical bioprosthetic disease and native MV disorders.

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.

Percutaneous transseptal transcatheter mitral valve-in-valve replacement for degenerated mitral bioprosthesis: The first experience in Japan

A 76-year-old woman had received surgical mitral valve replacement with Magna Mitral Ease (Edwards Lifesciences, Irvine, CA, USA) 25 mm for functional severe mitral regurgitation 6 years previously. She presented recurrence of heart failure due to severe stenotic and moderate regurgitant degeneration of the implanted mitral bioprosthesis. Considering her comorbidities and left ventricular systolic dysfunction, our heart valve team eventually decided to perform percutaneous transseptal transcatheter mitral valve-in-valve replacement instead of surgical redo mitral valve replacement, using a 26 mm SAPIEN 3 valve (Edwards Lifesciences) via trans-femoral approach. Post-procedural course was uneventful and she was discharged on post-procedural day 2. This is, to the best of our knowledge, the first case of successful percutaneous transseptal transcatheter mitral valve-in-valve replacement in Japan. Further large-scale prospective studies are warranted to validate its long-term safety and efficacy, particularly by comparing with the redo surgery.

<Learning objective: We experienced an off-label transseptal mitral valve-in-valve replacement using SAPIEN 3 to treat degenerative mitral bioprosthesis for the first time in Japan. Although further large-scale prospective studies are warranted, this procedure should be a promising therapeutic alternative to conventional redo-surgery, particularly for elderly patients with multiple comorbidities.>

Transcatheter Mitral Valve-in-Ring Implantation in the Flexible Adjustable Attune Annuloplasty Ring

Transcatheter mitral valve-in-ring implantation (TMViR) poses unique challenges when compared to valve-in-valve implantation due to the large variation in the different annuloplasty rings used. Annuloplasty rings are often classified according to whether they are complete or incomplete, rigid, semi-rigid, or flexible, and whether their three-dimensional geometry is saddle-shaped or flat. A limited number of annuloplasty rings are available which are adjustable allowing the surgeon to increase or decrease the size of the ring once it has been sutured in place. To our knowledge there has been no description of TMViR in such adjustable complete rings and recommendations on THV sizing and implantation are not available on the Valve-in-Valve application. Here we report a case of TMViR in an adjustable annuloplasty ring (Attune ring, Abbott, Chicago, IL, USA) and review the literature on TMViR.

Utility of Three-Dimensional Transesophageal Echocardiography for Mitral Annular Sizing in Transcatheter Mitral Valve Replacement Procedures: A Cardiac Computed Tomographic Comparative Study

BACKGROUND

Three-dimensional (3D) transesophageal echocardiographic (TEE) imaging is frequently used as an initial screening tool in the evaluation of patients who are candidates for transcatheter mitral valve replacement (TMVR). However, little is known about the imaging correlation with the gold standard, computed tomographic (CT) imaging. The aims of this study were to test the quantitative differences between these two modalities and to determine the best 3D TEE parameters for TMVR screening.

METHODS

Fifty-seven patients referred to the heart valve clinic for TMVR with prostheses specifically designed for the mitral valve were included. Mitral annular (MA) analyses were performed using commercially available software on 3D TEE and CT imaging.

RESULTS

Three-dimensional TEE imaging was feasible in 52 patients (91%). Although 3D TEE measurements were slightly lower than those obtained on CT imaging, measurements of both projected MA area and perimeter showed excellent correlations, with small differences between the two modalities (r = 0.88 and r = 0.92, respectively, P < .0001). Correlations were significant but lower for MA diameters (r = 0.68-0.72, P < .0001) and mitroaortic angle (r = 0.53, P = .0001). Receiver operating characteristic curve analyses showed that 3D TEE imaging had a good ability to predict TMVR screening success, defined by constructors on the basis of CT measurements, with ranges of 12.9 to 15 cm² for MA area (area under the curve [AUC] = 0.88-0.91, P < .0001), 128 to 139 mm for MA perimeter (AUC = 0.85-0.91, P < .0001), 35 to 39 mm for anteroposterior diameter (AUC = 0.79-0.84, P < .0001), and 37 to 42 mm for posteromedial-anterolateral diameter (AUC = 0.81-0.89, P < .0001).

CONCLUSIONS

Three-dimensional TEE measurements of MA dimensions display strong correlations with CT measurements in patients undergoing TMVR screening. Three-dimensional TEE imaging should be proposed as a reasonable alternative to CT imaging in this vulnerable population.

A fully automated software platform for structural mitral valve analysis

OBJECTIVE

To evaluate a novel fully automated mitral valve analysis software platform for cardiac computer tomography angiography (CCTA)-based structural heart therapy procedure planning.

METHODS

The study included 52 patients (25 women; mean age, 66.9 ± 12.4 years) who had undergone CCTA prior to transcatheter mitral valve replacement (TMVR) or surgical mitral valve intervention (replacement or repair). Therapeutically relevant mitral valve annulus parameters (projected area, circumference, trigone-to-trigone (T-T) distance, anterior-posterior (AP) diameter, and anterolateral-posteromedial (AL-PM) diameter) were measured. Results of the fully automated mitral valve analysis software platform with and without manual adjustments were compared with the reference standard of a user-driven measurement program (3mensio, Pie Medical Imaging). Measurements were compared between the fully automated software, both with and without manual adjustment, and the user-driven program using intraclass correlation coefficients (ICC). A secondary analysis included the time to obtain all measurements.

RESULTS

Fully automated measurements showed a good to excellent agreement (circumference, ICC = 0.70; projected area, ICC = 0.81; T-T distance, ICC = 0.64; AP, ICC = 0.62; and AL-PM diameter, ICC = 0.78) compared with the user-driven analysis. There was an excellent agreement between fully automated measurement with manual adjustments and user-driven analysis regarding circumference (ICC = 0.91), projected area (ICC = 0.93), T-T distance (ICC = 0.80), AP (ICC = 0.78), and AL-PM diameter (ICC = 0.79). The time required for mitral valve analysis was significantly lower using the fully automated software with manual adjustments compared with the standard assessment (134.4 ± 36.4 s vs. 304.3 ± 77.7 s) (p < 0.01).

CONCLUSION

The fully automated mitral valve analysis software, when combined with manual adjustments, demonstrated a strong correlation compared with the user-driven software while reducing the total time required for measurement.

KEY POINTS

• The novel software platform allows for a fully automated analysis of mitral valve structures. • An excellent agreement was found between the fully automated measurement with manual adjustments and the user-driven analysis. • The software showed quicker measurement time compared with the standard analysis of the mitral valve.

Transapical mitral valve-in-ring procedure with a novel self-expandable transcatheter heart valve: first- and last-in-man report

Interventional therapy of failing surgical mitral valve replacement and repair is an appealing option in patients who are not eligible for redo surgery. We herein report on the first-in-human use of a repositionable, self-expandable transcatheter heart valve with motorized delivery for a transapical mitral valve-in-ring procedure. After implantation, fluoroscopy showed no residual regurgitation and pressure measurements did not reveal any signs of left ventricular outflow tract obstruction.

Pre-procedural planning of transcatheter mitral valve replacement in mitral stenosis with multi-detector tomography-derived 3D modeling and printing: a case report

Background

Transcatheter mitral valve replacement (TMVR) may be a valuable treatment option for mitral annular calcification and severe mitral stenosis (MS) in patients at high operative risk. Pre-procedural virtual and printed simulations may aid in procedure planning, device sizing, and mitigate complications such as valve embolization or left ventricular outflow tract (LVOT) obstruction.

Case summary

We describe a case of TMVR in which multi-detector computed tomography (MDCT) derived, three-dimensional virtual planning and a 3D-printed model of the patients’ left heart provided enhanced understanding of an individual patient’s unique anatomy to determine feasibility, device sizing, and risk stratification. This resulted in deployment of an adequately sized valve. Post-TMVR LVOT obstruction was treated with LVOT balloon dilatation and percutaneous transluminal septal myocardial ablation.

Discussion

Advanced MDCT-derived planning techniques introduce consistent 3D modeling and printing to enhance understanding of intracardiac anatomical relationships and test device implantation. Still, static measurements do not feature haemodynamic factors, tissue, or device characteristics and do not predict device host interaction. Transcatheter mitral valve replacement is feasible in MS when adequately pre-procedurally planned. Multi-detector computed tomography-derived, 3D, virtual and printed models contribute to adequate planning in terms of determining patient eligibility, procedure feasibility, and device sizing. However, static 3D modeling cannot completely eliminate the risk of peri-procedural complications.

Mitral Annular Calcification: Association with Atherosclerosis and Clinical Implications

PURPOSE OF REVIEW

This review summarizes the pathophysiology of mitral annular calcification (MAC) with recent findings and current strategies for diagnosis and treatment.

RECENT FINDINGS

Major factors in MAC development seem to be shear stress of the flow past the mitral valve, local inflammation, and dysregulation in regulators of mineral metabolism. MAC itself poses daunting technical challenges. Implanting a valve on top of the calcium bar might lead to paravalvular leak (PVL) that is less likely to heal. Annular decalcification allows for better valve seating and potentially better healing and less PVL. This, however, comes with the risk for catastrophic atrioventricular groove disruption. MAC can be sharply dissected with the scalpel; the annulus can be reconstructed with the autologous pericardium. Transcatheter mitral valve replacement is a promising approach in the treatment of patients who are deemed high-risk surgical candidates with severe MAC. MAC is a multifactorial disease that has some commonalities with atherosclerosis, mainly regarding lipid accumulation and calcium deposition. It is of great clinical importance, being a risk marker of cardiovascular events (including sudden death) and, with its progression, can have a negative impact on patients' lives.

Prevention and Treatment of Left Ventricular Outflow Tract Obstruction After Transcatheter Mitral Valve Replacement

Transcatheter mitral valve replacement (TMVR) is a promising strategy for patients with mitral valve disease and no surgical options. Left ventricular outflow tract (LVOT) obstruction is a life-threatening complication of TMVR. Although there are no commercially available devices to prevent LVOT obstruction, the risk of it can be reduced by careful preprocedure planning and the use of novel modifications to commercially available devices. This article summarizes current techniques to prevent LVOT obstruction with an emphasis on electrosurgical strategies.

Transcatheter Double Valve-in-Valve Replacement of Aortic and Mitral Bioprosthetic Valves

Transcatheter aortic valve replacement (TAVR) is an evolving method which has become the treatment of choice in high-risk patients with severe aortic stenosis. Unlike TAVR, the experience with transcatheter mitral valve replacement (TMVR) remains at an early stage because of challenges of valve development and possible complications such as valve displacement and subsequent left ventricular outlet tract (LVOT) obstruction. Here we report a case of transcatheter double valve-in-valve replacement (TDVIVR) in a patient with severe mitral and aortic bioprosthetic valve stenosis, followed by an extensive literature review of the latest techniques and challenges in this field.

Transcatheter Mitral Valve Replacement with Intrepid

Transcatheter mitral valve replacement with the Intrepid device is intended for patients who need mitral valve replacement and who are at an increased risk for conventional surgery. The early published results of the early feasibility trial are reviewed as well as device design and the implant procedure. The Apollo trial is reviewed: a randomized trial of the Intrepid device versus conventional surgery including a single arm study for inoperable patients. The mitral valve structure, pathophysiology, and postimplant physiology pose unique hurdles for any transcatheter implant.

Transcatheter Mitral Valve Replacement with Tendyne

Mitral regurgitation is the most commonly occurring valvular heart disease in developed countries. Transcatheter mitral valve replacement (TMVR) has emerged as a novel potential therapy for patients with severe mitral valve disease who are unsuitable candidates for conventional surgery or transcatheter edge-to-edge mitral repair. TMVR with the Tendyne prosthesis has shown potential at short-term follow-up to be an effective and safe treatment alternative for high-risk patients with severe mitral valve disease.

Transcatheter Aortic Valve Replacement to Treat Left Ventricular Outflow Tract Obstruction and Significant Paravalvular Leak Following Transcatheter Mitral Valve Replacement

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PVL after TMVR with a Tendyne device can result in severe intravascular hemolysis.

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SAM of the mitral valve can cause anterior PVL following Tendyne TMVR.

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TAVR can relieve LVOT obstruction caused by SAM after Tendyne TMVR.

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Pre-, peri-, and postprocedural imaging is key in decision making.