Open Atrial Transcatheter Mitral Valve Replacement in Patients With Mitral Annular Calcification

Early outcomes following transatrial transcatheter mitral valve replacement in patients with severe mitral annular calcification

OBJECTIVE

Implantation of a transcatheter valve-in-mitral annular calcification (ViMAC) has emerged as an alternative to traditional surgical mitral valve (MV) replacement. Previous studies evaluating ViMAC aggregated transseptal, transapical, and transatrial forms of the procedure, leaving uncertainty about each technique's advantages and disadvantages. Thus, we sought to evaluate clinical outcomes specifically for transatrial ViMAC from the largest multicenter registry to-date.

METHODS

Patients with symptomatic MV dysfunction and severe MAC who underwent ViMAC were enrolled from 12 centers across the United States and Europe. Clinical characteristics, procedural details, and clinical outcomes were abstracted from the electronic record. The primary end point was all-cause mortality.

RESULTS

We analyzed 126 patients who underwent ViMAC (median age 76 years [interquartile range {IQR}, 70-82 years], 28.6% female, median Society of Thoracic Surgeons score 6.8% [IQR, 4.0-11.4], and median follow-up 89 days [IQR, 16-383.5]). Sixty-one (48.4%) had isolated mitral stenosis, 25 (19.8%) had isolated mitral regurgitation (MR), and 40 (31.7%) had mixed MV disease. Technical success was achieved in 119 (94.4%) patients. Thirty (23.8%) patients underwent concurrent septal myectomy, and 8 (6.3%) patients experienced left ventricular outflow tract obstruction (7/8 did not undergo myectomy). Five (4.2%) patients of 118 with postprocedure echocardiograms had greater than mild paravalvular leak. Thirty-day and 1-year all-cause mortality occurred in 16 and 33 patients, respectively. In multivariable models, moderate or greater MR at baseline was associated with increased risk of 1-year mortality (hazard ratio, 2.31; 95% confidence interval, 1.07-4.99, P = .03).

CONCLUSIONS

Transatrial ViMAC is safe and feasible in this selected, male-predominant cohort. Patients with significant MR may derive less benefit from ViMAC than patients with mitral stenosis only.

Open transcatheter double valve-in-valve replacement for degenerated bioprostheses on the arrested heart

Background

Failing bioprosthesis is an emerging issue due to (i) a shift towards liberal bioprosthesis implantation instead of mechanical prosthesis and (ii) an ageing population. Management of high-risk patients with bioprosthesis degeneration remains challenging.

Case summary

An 82-year-old patient with history of aortic and mitral valve replacement six years before presents with severe dyspnoea. Echocardiograpic assessment reveals (i) structural valve degeneration of the mitral prosthesis (severe stenosis and regurgitation) with concomitant major annular calcifications and (ii) structural valve degeneration of the aortic prosthesis with low-flow, low-gradient restenosis. Due to mitral annular calcifications, the risk of double valve re-replacement and the age of the patient conventional reoperation was deemed very high. The patient is evaluated for transapical double valve implantation. This option is rejected due to the high risk of left ventricular outflow obstruction. The patient is treated with an open transcatheter double valve-in-valve procedure at the following sequence: leaflet resection of the mitral bioprosthesis, mitral valve implantation and fixation under direct view, leaflet resection of the aortic bioprosthesis, and valve frame cracking and aortic valve implantation under direct view. Post-bypass echocardiography shows neither left ventricular outflow tract obstruction nor paravalvular leak or prosthesis dysfunction. The patient is extubated on the first post-operative day and transferred to normal care unit.

Discussion

Open transcatheter double valve-in-valve replacement for degenerated bioprostheses on the arrested heart might be a valuable alternative to treat selected high-risk patients with bioprosthetic valve degeneration.

Double-layer horizontal cross sutures for intra-atrial mitral valve implantation: An effective surgical method for severe mitral annular calcification

Objective

Severe mitral annular calcification (MAC) can make prosthetic implantation extremely difficult. Although intra-atrial mitral valve prosthesis implantation without annular decalcification offers a simpler approach, it poses a potential rupture risk due to high left ventricular pressure. We developed a double-layer (DL) horizontal cross-suture technique, which ensures close proximity of the valve prosthesis to the calcified annulus and segregates the left atrial wall from the left ventricle. The aim of this study was to compare the outcomes of DL suture with conventional single-layer (SL) suture in patients with severe MAC.

Methods

This retrospective cohort study consecutively enrolled patients with severe MAC undergoing mitral valve replacement at Beijing Anzhen Hospital from May 2018 to December 2022. A detailed description of the DL suture method is described. Follow-up medical evaluations, including transthoracic echocardiography measurements, were obtained through outpatient chart reviews.

Results

The study included 10 patients in the DL suture group and 20 in the SL suture group. All patients in the DL group and all but 3 in the SL group achieved technical success. Compared with the SL group, the DL suture technique was associated with lower rates of perivalvular leakage, stroke, new-onset atrial fibrillation, reoperation, and 30-day mortality. Follow-up was complete, with 1 late mortality in the DL group due to stroke and 4 cardiovascular deaths in the SL group.

Conclusions

The DL horizontal cross-suture technique offers a more effective and safer approach for intra-atrial mitral valve implantation in severe MAC cases than the conventional SL suture method.

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.

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

Flow dynamic assessment of native mitral valve, mitral valve repair and mitral valve replacement using vector flow mapping intracardiac flow dynamic in mitral valve regurgitation

Objectives

The present study aims to assess and describe the intracardiac blood flow dynamic in patients with mitral regurgitation (MR), repaired mitral valves (MV) and mitral valve prostheses using vector flow mapping (VFM).

Methods

Patients with different MV pathologies and MV disease treatments were analysed. All patients underwent 2D transthoracic echocardiography, and images for flow visualization were acquired in VFM mode in an apical three-chamber view and four-chamber view. Vectors and vortices were qualitatively analyzed.

Results

thirty-two (32) patients underwent 2D transthoracic echocardiography (TTE) with VFM analysis. We evaluated intracardiac flow dynamics in 3 healthy subjects, 10 patients with MR (5 degenerative, 5 functional), 4 patients who underwent MV repair, 5 who underwent MV replacement (3 biological, 2 mechanical), 2 surgically implanted transcatheter heart valve (THV), 2 transcatheter edge-to-edge MV repair with MitraClip (TEER), 3 transcatheter MV replacement (TMVR) and 3 transapical off-pump MV repair with NeoChord implantation. Blood flow patterns are significantly altered in patients with MV disease and MV repair compared to control patients. MV repair is superior to replacement in restoring more physiologicalpatterns, while TMVR reproducesan intraventricular flowcloser to normal than surgical MVR and TEER.

Conclusions

Intracardiac flow patterns can be clearly defined using VFM. Restoration of a physiological blood flow pattern inside the LV directly depends on the procedure used to address MV disease.

Preemptive Septal Radiofrequency Ablation to Prevent Left Ventricular Outflow Tract Obstruction With Transcatheter Mitral Valve Replacement: A Case Series

BACKGROUND

Left ventricular outflow tract obstruction may occur following transcatheter mitral valve replacement in the setting of mitral annular calcification.

METHODS

We present a case series whereby preemptive septal radiofrequency ablation (RADIO-TMVR) was used to augment the left ventricular outflow tract for transcatheter mitral valve replacement in 4 patients at risk for left ventricular outflow tract obstruction despite alcohol septal ablation.

RESULTS

All patients were female, average age of 74.9 (68.8-80.4) years. Baseline ejection fraction was 71% (63%-75%). Mean mitral valve area was 1.28 (range, 1.0-1.59) cm². Mean mitral valve gradient at rest was 9.5 (range, 7-11) mm Hg. New York Heart Association symptoms were III to IV at baseline. Patients underwent preemptive septal radiofrequency ablation to prevent left ventricular outflow tract obstruction with transcatheter mitral valve replacement a range between 69 and 154 days after alcohol septal ablation. Procedural time was 384 (337-424) minutes with a fluoroscopic time of 31 (14-71) minutes. Radiofrequency ablation time was 132 (100-175) minutes. As anticipated, 3 patients developed complete heart block and underwent pacemaker implantation, whereas 1 had a preexisting pacemaker. One patient developed groin hematoma and heart failure exacerbation. There were no peri-procedural deaths. Preemptive septal radiofrequency ablation to prevent left ventricular outflow tract obstruction with transcatheter mitral valve replacement resulted in septal end-diastolic wall thickness reduction compared with baseline (28.6%, 30.4%, 30.3%, and 11.1%) and following alcohol septal ablation (23.1%, 12%, 8.5%). Valve replacement in the setting of mitral annular calcification was performed in all patients 89 (range, 38-45) days after preemptive septal radiofrequency ablation to prevent left ventricular outflow tract obstruction with transcatheter mitral valve replacement. Two patients had concomitant laceration of the anterior mitral leaflet to further augment the neo-left ventricular outflow tract. Postprocedure, New York Heart Association symptoms improved to class I (3 patients) and class II (1 patient).

CONCLUSIONS

In at-risk individuals, preemptive septal radiofrequency ablation may be an effective strategy at preventing left ventricular outflow tract obstruction with transcatheter mitral valve replacement.

Management of Patients With Severe Mitral Annular Calcification: JACC State-of-the-Art Review

Mitral annular calcification (MAC) is a common and challenging pathologic condition, especially in the context of an aging society. Surgical mitral valve intervention in patients with MAC is difficult, with varying approaches to the calcified annular anatomy, and the advent of transcatheter valve interventions has provided additional treatment options. Advanced imaging provides the foundation for heart team discussions and management decisions concerning individual patients. This review focuses on the prognosis of, preoperative planning for, and management strategies for patients with MAC.

Right Mini-Thoracotomy Beating Heart Mitral Valve Replacement with a SAPIEN 3 Valve for Severe Circumferential Mitral Annular Calcification

Mitral annular calcification (MAC) is a degenerative process that can cause mitral valve stenosis. Conventional surgical mitral valve replacement (MVR) for MAC with mitral stenosis can be challenging and associated with significant risk. Open surgical MVR with a transcatheter valve can offer an alternative in select situations. When such a strategy is not feasible, a beating-heart, mini-thoracotomy MVR with a SAPIEN 3 transcatheter heart valve can be considered. The novel teaching point of this case is use of an alternative approach for managing severe mitral stenosis secondary to MAC, when conventional surgical and transcatheter strategies are not safe or possible.

Hybrid Surgery for Severe Mitral Valve Calcification: Limitations and Caveats for an Open Transcatheter Approach

Background and Objectives: Mitral stenosis with extensive mitral annular calcification (MAC) remains surgically challenging in respect to clinical outcome. Prolonged surgery time with imminent ventricular rupture and systolic anterior motion can be considered as a complex of causal factors. The aim of our alternative hybrid approach was to reduce the risk of annual rupture and paravalvular leaks and to avoid obstruction of the outflow tract. A review of the current literature was also carried out. Materials and Methods: Six female patients (mean age 76 ± 9 years) with severe mitral valve stenosis and severely calcified annulus underwent an open implantation of an Edwards Sapien 3 prosthesis on cardiopulmonary bypass. Our hybrid approach involved resection of the anterior mitral leaflet, placement of anchor sutures and the deployment of a balloon expanded prosthesis under visual control. Concomitant procedures were carried out in three patients. Results: The mean duration of cross-clamping was 95 ± 31 min and cardiopulmonary bypass was 137 ± 60 min. The perioperative TEE showed in three patients an inconspicuous, heart valve-typical gradient on all implanted prostheses and a clinically irrelevant paravalvular leakage occurred in the anterior annulus. In the left ventricular outflow tract, mild to moderately elevated gradients were recorded. No adverse cerebrovascular events and pacemaker implantations were observed. All but one patient survived to discharge. Survival at one year was 83.3%. Conclusions: This "off label" implantation of the Edwards Sapien 3 prosthesis may be considered as a suitable bail-out approach for patients at high-risk for mitral valve surgery or deemed inoperable due to extensive MAC.

Impact of aortic valve replacement for severe aortic stenosis on organic and functional mitral regurgitation

AIMS

Concurrent mitral regurgitation (MR) influences treatment considerations in patients with severe aortic stenosis (sAS). Limited information exists regarding haemodynamic effects of sAS on MR severity and outcome of these patients. We assessed the impact of aortic valve replacement (AVR) on MR according to mechanism in patients with sAS and MR.

METHODS AND RESULTS

In patients with sAS who received surgical or transcatheter AVR from 2008 to 2017, those with effective mitral regurgitant orifice area (ERO) ≥ 10 mm2 prior to AVR were evaluated. The change in MR after AVR was considered significant when there was at least one grade difference. We compared the all-cause mortality of patients with and without improvement in MR. Of 234 patients with sAS and MR (age 80 ± 9 years, 52% male, ERO 19 ± 7 mm2 ), organic and functional MR were present in 166 (71%) and 68 (29%), respectively. MR improved in 136 (58%); improvement occurred with similar frequency in organic versus functional MR (59% and 57%, P = 0.88). Associated determinants were absence of atrial fibrillation in organic MR [odds ratio (OR) 2.09, 95% confidence interval (CI) 1.00-4.37; P = 0.049] and indexed aortic valve area (iAVA) ≤ 0.40 cm2 in functional MR (OR 3.28, 95% CI 1.13-9.47; P = 0.028). In the overall cohort, mitral annulus diameter < 3 cm (OR 1.74, 95% CI 1.02-2.97; P = 0.041) and QRS duration < 115 ms (OR 1.73, 95% CI 1.00-2.98; P = 0.049) were independently associated with improvement in MR. During median follow-up of 3.5 years, lack of improvement in MR was not associated with higher mortality in the overall cohort of patients with ERO ≥ 20 mm2 [adjusted hazard ratio (HR) 1.71, 95% CI 0.90-3.27; P = 0.10, adjusted for age, New York Heart Association III or IV, diabetes, and creatinine ≥ 2.0 mg/dL]. Lack of improvement in organic MR was associated with higher mortality (adjusted HR 3.36, 95% CI 1.40-8.05; P < 0.01). In patients with functional MR, change in MR was not associated with mortality (HR 1.24, 95% CI 0.44-3.47; P = 0.68).

CONCLUSIONS

In nearly 60% of patients with sAS and MR, MR improved after AVR, even in the majority of patients with organic MR. Absence of atrial fibrillation in organic MR, iAVA ≤ 0.40 cm2 in functional MR, and mitral annulus diameter < 3 cm and QRS duration < 115 ms in the overall population were associated with MR improvement. Post-operative improvement in organic MR was associated with better survival.

Open transcatheter valve implantation for mitral annular calcification: One-year outcomes

Background

Transcatheter mitral valve implantation (TMVI) for native mitral valve pathology with severe mitral annular calcification has emerged as an alternative treatment option to conventional mitral valve surgery. The objective of this study was to evaluate patients who were referred for TMVI with severe mitral annular calcification and their procedural outcomes.

Methods

Retrospective analysis of patients from 2017 to 2020 referred for TMVI was carried out. Demographic characteristic details; surgical strategy; perioperative complications; and hospital stay, including 30-day and 1-year mortality, were analyzed.

Results

Eleven patients were referred for consideration of TMVI. The 8 patients who underwent TMVI had a median age of 74 years (range, 57-80 years), the median Society of Thoracic Surgeons score was 4.6 (range, 2.4-10.9), and European System for Cardiac Operative Risk Evaluation II score was 5.2% (2%-10.1%). The median cardiopulmonary bypass time and crossclamp times were 170 minutes (range, 150-248 minutes) and 152 minutes (range, 118-214 minutes), respectively. The median hospital stay was 29 days (range, 2-40 days). Thirty-day in hospital mortality was 12%, whereas 1-year mortality was 25%. There was symptomatic improvement with downgrade of New York Heart Association functional class from III or IV to I or II. The 3 patients who were turned down had a median age of 73 years, median Society of Thoracic Surgeons score was 13.4, and median European System for Cardiac Operative Risk Evaluation II score was 5.72%. They were alive at 12 months follow-up from the date of surgical assessment; however, all with New York Heart Association functional class III or IV symptoms.

Conclusions

We describe a series demonstrating the technical consideration and capability of transatrial TMVI to treat mitral annular calcification and native mitral valve disease. Our results are favorable when compared with TMVI global registry data for transseptal or transapical approach.

Non-Aortic Valve Cardiac Surgery after Transcatheter Aortic Valve Replacement

BACKGROUND

Despite the rapid adoption of transcatheter aortic valve replacement (TAVR), the frequency and outcomes of non-aortic valve cardiac surgery after TAVR are unknown.

METHODS

Non-aortic valve surgery after TAVR from 2011 to 2019 was queried using the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database. A total of 666 patients, including 47 (7.1%) unplanned TAVR-explant and 3 (0.5%) aborted procedures during non-aortic valve procedures, were identified.

RESULTS

These 666 procedures were performed by 459 surgeons (median 1.0 case per surgeon) from 308 centers (median 1.0 case per center), which represents 29% of Database participants. The case number increased over time from 4 in 2011 to 204 in 2019, largely attributable to coronary artery bypass grafting (CABG) (n=283; 42.5%) and mitral (n=258; 38.7%) procedures. The median age was 75.0 and 51.4% had previous cardiac surgeries. The 30-day mortality of the entire cohort was 17.0%. Subgroups with particularly high mortality included patients with robot-assisted mitral surgery (n=5/12; 41.7%), unplanned TAVR-explant (n=19/47; 40.4%), open atrial transcatheter mitral valve replacement (n=10/33; 30.3%) and aortic repair (n=24/79; 29.8%). Among 390 patients with available STS predicted risk of mortality, the 30-day mortality with isolated CABG, isolated mitral repair/replacement and the entire group was 8.4% (n=19/225), 13.5% (n=21/155) and 10.8% (n=42/390) with corresponding observed-to-expected mortality (O/E) ratio of 1.8, 1.8 and 1.7, respectively.

CONCLUSIONS

Non-aortic valve operation after TAVR was associated with a high mortality and O/E ratio. Implanters must be mindful of "lifetime management" strategy including assessment of concurrent pathologies during TAVR candidate selection.

Predictors of Left Ventricular Outflow Tract Obstruction After Transcatheter Mitral Valve Replacement in Severe Mitral Annular Calcification: An Analysis of the Transcatheter Mitral Valve Replacement in Mitral Annular Calcification Global Registry

[Figure: see text].

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.

Early outcomes of transatrial mitral valve replacement in severe mitral annular calcification

Objective

Mitral valve replacement (MVR) in the setting of severe mitral annular calcification is a technically challenging operation with increased morbidity and mortality. Transseptal/apical transcatheter MVR (TMVR) in mitral annular calcification has emerged as an option for these cases, although may not be feasible due to anatomical reasons. Transatrial TMVR is a potential treatment option for this subgroup of patients.

Methods

Patients who underwent transatrial TMVR between June 2018 and November 2020 at a single institution were included. Patients were selected by a structural heart team based on their surgical risk, pattern of mitral annular calcification, risk of valve migration, left ventricular outflow obstruction, and paravalvular leak.

Results

A total of 11 patients underwent transatrial TMVR. Mean patient age was 74.2 years and mean Society of Thoracic Surgeons predicted risk of mortality score was 9.1%. All patients had the presence of both mitral stenosis and regurgitation—dominant etiology—was mitral stenosis in 81.2%, and mitral regurgitation in 18.8%. Among patients, 54.5% had a concomitant cardiac procedure. There was no in-hospital or 30-day mortality. Technical success defined by the Mitral Valve Academic Research Consortium was achieved in 90.9% of patients. Postoperative paravalvular leak was mild or less in all patients.

Conclusions

In this series, transatrial TMVR was shown to be a safe and effective treatment option for patients who are high risk for surgical MVR and should be in surgeons' armamentarium in the treatment of this high-risk patient population. Dissemination of safe technique will be critical in the successful conduct of this surgery.

How to Manage Mitral Stenosis Due to Mitral Annular Calcification

PURPOSE OF REVIEW

Mitral annular calcification (MAC) is associated with cardiovascular comorbidities and events and in the presence of mitral stenosis (MS) represents a high-risk cohort with limited treatment options. Emerging hybrid, minimally invasive, and transcatheter therapies that use circumferential MAC as an anchor for mitral valve replacement are emerging, but none are consistently associated with ideal outcomes.

RECENT FINDINGS

In patients with MAC and nonrheumatic calcific mitral stenosis who are severely symptomatic, mitral intervention may be indicated. Surgical decalcification and replacement of the mitral valve remains the conventional therapy. Surgical techniques to avoid decalcification are being described including a left atrium to left ventricular apex graft conduit. Transcatheter balloon-expandable valves designed for the aortic valve have been implanted in the mitral position in MAC with a surgical direct transatrial transcatheter approach or transseptal transcatheter approach. Left ventricular outflow tract (LVOT) obstruction remains prevalent and associated with increased mortality. Direct transatrial approach allows for surgical resection of the anterior leaflet to mitigate this risk, and percutaneous therapies to lacerate the anterior leaflet or to ablate the basal septum are being developed. Cardiac computed tomography has emerged as a requisite for patient selection and procedural planning and has powerful predictive value for LVOT obstruction and valve embolization in valve-in-MAC. Novel transcatheter valves designed specifically for the mitral space are being studied in patients with MAC. MAC with mitral stenosis remains a challenging disease. Advances in technique, technology, and imaging may create new and reproducible treatment options with low procedural mortality for this challenging disease entity.

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.

Current Devices and Complications Related to Transcatheter Mitral Valve Replacement: The Bumpy Road to the Top

Mitral regurgitation is the most common valvular lesion in the developed world, with increasing prevalence, morbidity, and mortality. The experience with surgical mitral valve repair or replacement is very well-validated. However, more than 45% of these patients get denied surgery due to an elevated risk profile and advanced disease of the left ventricle at the time of presentation, promoting the need for less invasive transcatheter options such as transcatheter repair and transcatheter mitral valve replacement (TMVR). Early available TMVR studies have shown promising results, and several dedicated devices are under clinical evaluation. However, TMVR is still in the early developmental stages and is associated with a non-negligible risk of periprocedural and post-procedural complications. In this review, we discuss the current challenges facing TMVR and the potential TMVR-related complications, offering an overview on the measures implemented to mitigate these complications, and future implications.

Hemolysis after transcatheter mitral valve replacement in degenerated bioprostheses, annuloplasty rings, and mitral annular calcification: Incidence, patient characteristics, and clinical outcomes

OBJECTIVES

To determine the incidence, characteristics, and outcomes of patients with hemolysis after transcatheter mitral valve replacement (TMVR).

BACKGROUND

Hemolysis is an increasingly recognized complication of TMVR. Clinical outcomes and optimal management for patients with hemolysis after TMVR are unclear.

METHODS

Patients that underwent mitral valve-in-valve (MViV), valve-in-ring (MViR), and valve-in-mitral annular calcification (ViMAC) at a single center were retrospectively assessed.

RESULTS

A total of 101 patients had TMVR, including 69 with MViV, 14 with MViR, and 18 with ViMAC. ViMAC patients had an increased frequency of mild or greater paravalvular leak (PVL) (ViMAC, 72.2%; MViR, 14.3%; MViV, 13.0%; p < .001). Hemolysis occurred in eight patients and was more common after ViMAC (ViMAC, 33.3%; MViR, 7.1%; MViV, 1.5%; p < .001). This required transfusion in five (ViMAC, 4; MViV, 1) and was associated with acute kidney injury in five with ViMAC. Among the ViMAC patients, four had transcatheter re-intervention to treat hemolysis with resolution of anemia in three and mild residual anemia in one with persistent mild PVL. The two ViMAC patients without re-intervention had persistent anemia and died within 6 months. Both MViV and MViR patients with hemolysis did not have PVL but had turbulent flow from left ventricular outflow tract narrowing and their hemolysis was self-limited.

CONCLUSIONS

Hemolysis occurs with greater frequency and increased clinical severity after ViMAC as compared to MViV or MViR and is likely related to increased incidence of PVL. These findings demonstrate the need to investigate novel strategies that can reduce the burden of hemolysis with ViMAC.

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.

Surgical and Transcatheter Mitral Valve Replacement in Mitral Annular Calcification: A Systematic Review

Mitral annular calcification with mitral valve disease is a challenging problem that could necessitate surgical mitral valve replacement (SMVR). Transcatheter mitral valve replacement (TMVR) is emerging as a feasible alternative in high-risk patients with appropriate anatomy. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to December 25, 2019 for studies discussing SMVR or TMVR in patients with mitral annular calcification; 27 of 1539 articles were selected for final review. TMVR was used in 15 studies. Relevant data were available on 82 patients who underwent hybrid transatrial TMVR, and 354 patients who underwent transapical or transseptal TMVR. Outcomes on SMVR were generally reported as small case series (447 patients from 11 studies); however, 1 large study recently reported outcomes in 9551 patients. Patients who underwent TMVR had a shorter median follow-up of 9 to 12 months (range, in-hospital‒19 months) compared with patients with SMVR (54 months; range, in-hospital‒120 months). Overall, those undergoing TMVR were older and had higher Society of Thoracic Surgeons risk scores. SMVR showed a wide range of early (0%-27%; median 6.3%) and long-term mortality (0%-65%; median at 1 year, 15.8%; 5 years, 38.8%, 10 years, 62.4%). The median in-hospital, 30-day, and 1-year mortality rates were 16.7%, 22.7%, and 43%, respectively, for transseptal/transapical TMVR, and 9.5%, 20.0%, and 40%, respectively, for transatrial TMVR. Mitral annular calcification is a complex disease and TMVR, with a versatile option of transatrial approach in patients with challenging anatomy, offers a promising alternative to SMVR in high-risk patients. However, further studies are needed to improve technology, patient selection, operative expertise, and long-term outcomes.

Anatomic classification of mitral annular calcification for surgical and transcatheter mitral valve replacement

BACKGROUND AND AIM OF THE STUDY: A systematic approach to quantify mitral annular calcification (MAC) in all-comers by multidetector computed tomography (MDCT) is essential to guide treatment, but lacking.

METHODS

From September 2015 to July 2019, 82 patients with MAC underwent MDCT at two institutions to evaluate for surgical mitral valve replacement (SMVR), transcatheter mitral valve replacement (TMVR), or medical management. Type 1 MAC was defined as <270° annular calcium and Type 2 as ≥270°. Absence/presence of predicted left ventricular outflow tract (LVOT) obstruction with virtual valve placement was used to further define Type 2 MAC into 2A/B for our treatment algorithm.

RESULTS

Type 1 MAC was present in 51.2%, Type 2A in 18.3%, and Type 2B in 30.5%. Operable Type 1 patients (50.0%) underwent hybrid transatrial TMVR or SMVR. Type 2A underwent a variety of treatments, and Type 2B surgical candidates (40.0%) underwent hybrid transatrial TMVR secondary to difficult suture anchoring with significant MAC and predicted LVOT obstruction. At a follow-up of 29.6 ± 12.0 months, mortality was 42.7% with 46.3% in the intervention group and 39.0% in the medical group (p = 0.47). All percutaneous TMVR patients expired. This translated to a disproportionate number of Type 2A deaths (80.0% with intervention), but all were high/extreme surgical risk. The hybrid TMVR group consisted of 95.0% Type 1/2B patients and had a lower Society of Thoracic Surgeons predicted risk of operative mortality (7.4% vs. 9.2%, p = 0.43)/mortality.

CONCLUSIONS

The highest mortality was seen in percutaneous TMVR Type 2A MAC patients, but they were at the greatest risk. Here we provide an objective MAC treatment algorithm for all-comers based on operability/anatomy.

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.

Temporal outcomes of transcatheter mitral valve replacement in native mitral valve disease with annular calcification

BACKGROUND

Surgical intervention in patients with native mitral disease due to severe mitral annular calcification (MAC) carries significant risk. Transcatheter mitral valve replacement (TMVR) using balloon-expandable aortic transcatheter heart valve (THV) in MAC had emerged as alternative treatment.

OBJECTIVES

We aim to study the temporal change in clinical outcomes of the procedure at a single center.

METHODS

We retrospectively studied 23 patients who underwent TMVR in MAC at Mayo Clinic from January, 14, 2014 to March, 15, 2019. Cases were divided into early (n = 11) and late (n = 12) experience. The primary end point was 30-day all-cause mortality. The secondary end points were immediate technical success, 30-day procedural success, and 1-year all-cause mortality.

RESULTS

Mean age of patients was 75.2 ± 8.9 years and 17 (74.0%) were female. Median STS score for 30-day mortality was 8 (Interquartile range 4.3-13.4) for the entire population. Immediate technical success was achieved in 21 out of 23 patients (two failures in the early experience were related to tamponade and procedural death). Thirty-day procedural success was higher in the late experience (10 out of 12 patients) compared to early experience (5 out of 11 patients, p = .06). Four deaths in the first 30-days were observed in the early experience while all patients survived to hospital discharge in the late experience (p = .01).

CONCLUSIONS

Procedural success and 30-day survival of transcatheter mitral valve replacement in severe mitral annular calcification procedure using balloon-expandable aortic prosthesis had improved over the years. This is likely attributed to significant advancement in procedural planning, valve design, and techniques.

Hybrid Double Valve Replacement for Multivalvular Disease With Severe Mitral Annular Calcification

Severe mitral annular calcification poses a significant challenge, particularly in higher risk, frail, elderly patients with multivalvular disease. Both surgical and transcatheter options exist but remain fraught with risks of paravalvular leak, atrioventricular groove disruption, patient prosthesis mismatch, and left ventricular outflow tract obstruction. We present an innovative hybrid surgical approach to manage severe aortic and mitral valve disease in a Jehovah's Witness patient with severe circumferential mitral annular calcification.

Current Indications for Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valves

Use of transcatheter mitral valve replacement (TMVR) using transcatheter aortic valves in clinical practice is limited to patients with failing bioprostheses and rings or mitral valve disease associated with severe mitral annulus calcification. Whereas the use of valve-in-valve TMVR appears to be a reasonable alternative to surgery in patients at high surgical risk, much less evidence supports valve-in-ring and valve-in-mitral annulus calcification interventions. Data on the results of TMVR in these settings are derived from small case series or voluntary registries. This review summarizes the current evidence on TMVR using transcatheter aortic valves in clinical practice from the characteristics of the TMVR candidates, screening process, performance of the procedure, and description of current results and future perspectives. TMVR using dedicated devices in native noncalcified mitral valve diseases is beyond the scope of the article.

Current Devices in Mitral Valve Replacement and Their Potential Complications

Mitral regurgitation is one of the most prevalent valvulopathies worldwide, and its surgical treatment is not feasible in all cases. The elderly and frail with several comorbidities and left ventricular dysfunction are often managed conservatively. Percutaneous treatment (repair or replacement) of the mitral valve has emerged as a potential option for those patients who are at a high risk for surgery. Mitral valve repair with the Mitraclip device proved both increased safety and mortality reduction in patients with severe mitral regurgitation. On the other hand, in the last decade, percutaneous mitral replacement opened new frontiers in the field of cardiac structural interventions. There are few mitral devices; some are in the early phase of development and some are waiting for CE mark of approval. The evolution of these devices was more complicated compared to the aortic technology due to the native mitral valve's complexity and access. This review aims to provide an overview of the current devices, their specific features, and their potential complications.

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.

Transcatheter "valve-in-valve" mitral valve replacement for patient-prosthesis mismatch: Chronicle of a death foretold

Severe mitral annular calcification (MAC) may represent a challenging issue which can lead to poor outcomes and serious issues such as patient-prosthesis mismatch (PPM). The potential harmful effect of PPM must be prevented through the use of alternative techniques that allow mitral valve replacement with adequately sized bioprostheses in patients with MAC. PPM should be recognized as a contraindication for transcatheter valve-in-valve replacement as it leads to poor outcomes and early prosthetic degeneration.

Transcatheter Mitral Valve Replacement: Procedural Planning, Utility, and Applicability

Since the first native transcatheter mitral valve implantation in 2012, transcatheter mitral valve replacement (TMVR) has expanded its use to degenerated bioprostheses, failed annuloplasty ring repair, and mitral annular calcification. However, high-screen failure rates in trials have persisted due to predicted left ventricular outflow tract obstruction and unfavorable anatomy. Preprocedural planning in this patient population with multidetector computed tomography and transesophageal echocardiography is paramount to intraprocedural success. In patients with favorable left ventricular outflow tract anatomy who are not surgical candidates, the transseptal approach is preferred. In those who are surgical candidates, TMVR can be performed via a transapical or transatrial approach. Currently, a plethora of TMVR devices targeting the native mitral pathologies are undergoing clinical trials. Data have consistently shown the greatest benefit of this procedure in native mitral regurgitation and failed bioprostheses rather than failed annuloplasty rings or mitral annular calcification. With technological advancement and careful patient selection, this therapy will serve as a complement to surgical and TMV repair and will continue to expand to address MV diseases in a broader patient population.

Contemporary Surgical and Transcatheter Management of Mitral Annular Calcification

BACKGROUND

The presence of mitral annular calcification (MAC) in patients with mitral valve (MV) stenosis or regurgitation is a difficult scenario for surgeons and the heart team. Patients with MAC most often have a significant number of comorbidities that exclude them as surgical candidates. This review highlights the various contemporary techniques available to manage MAC during treatment of the MV.

METHODS

This study is a focused review of the anatomy, pathology, and management of MAC. The review describes the surgical and transcatheter techniques with outcomes, where available.

RESULTS

The incidence of MAC is between 5% and 42% in patients with severe MV disease. The pathophysiology underlying MAC is not yet clear, but it most likely is related to processes of inflammation and atherosclerosis. Surgical techniques can be grouped into those in which the MAC is completely resected en bloc and those in which the MAC is incompletely resected or left in situ. Transcatheter therapies are feasible in some patients, but they have been limited by the anatomic constraints of MAC; most importantly left ventricular outflow tract obstruction and paravalvular regurgitation.

CONCLUSIONS

Surgeons as part of the heart team now have a range of techniques to manage MAC in those patients with severe MV disease. Transcatheter therapies may increase the options for patients whose surgical risk is too high.

Urgent Open Atrial Transcatheter Mitral Valve Replacement as Bailout for Planned Surgery

Hybrid transcatheter mitral valve replacement (TMVR) has shown great promise for patients with severe mitral annular calcification. However, there have been limited reports of its use as a bailout for planned surgical MVR. Here, we present a bailout TMVR with an excellent patient outcome. (Level of Difficulty: Advanced.)

Role of 3-dimensional transesophageal echocardiography in guiding transcatheter mitral valve replacement

BACKGROUND

Transcatheter mitral valve replacement technologies have been developed to treat a wide range of mitral valve pathologies including primary and secondary mitral regurgitation, mitral stenosis, in addition to degenerative bioprosthetic valves and failed annuloplasty rings.

OBJECTIVE

Transesophageal echocardiography, particularly with use of 3-dimensional imaging is key in successfully guiding these interventions. In this review, we highlight the key role of 3D transesophageal echocardiography in guiding TMVR, including valve-in-native valve, valve-in-prosthetic valve, valve-in-prosthetic ring, and valve-in-mitral annular calcification interventions.