The Art of SAPIEN 3 Transcatheter Mitral Valve Replacement in Valve-in-Ring and Valve-in-Mitral-Annular-Calcification Procedures

The American Association for Thoracic Surgery (AATS) 2025 Expert Consensus Document: Surgical management of mitral annular calcification

OBJECTIVE

Surgery for mitral valve disease in patients with mitral annular calcification (MAC) remains challenging. There is no consensus on the ideal management strategy or patient selection, and perioperative and periprocedural morbidity and mortality rates remain high. The recent surge of patients presenting with MAC has been accompanied by increased interest in MAC surgery and interventions. This expert consensus document is meant to provide a simplified outline for managing MAC, including patient selection, imaging, and surgical and transcatheter therapeutic options, with a particular focus on conventional surgical techniques and hybrid approaches.

METHODS

The American Association for Thoracic Surgery Clinical Practice Standards Committee assembled an international panel of cardiac surgeons and structural heart interventionalists with established expertise in the field of MAC. A comprehensive literature review was performed by the panel and a medical librarian. Clinical recommendations were developed utilizing a modified Delphi method.

RESULTS

Expert consensus was reached on 33 recommendations, with class of recommendation and level of evidence, for each of 5 main topics: (1) preoperative evaluation for patients with MAC, patient selection, and indications for intervention; (2) standard surgical techniques in MAC; (3) hybrid procedures in MAC; (4) transcatheter MAC interventions; and (5) complications and bailout of MAC surgery and interventions.

CONCLUSIONS

Despite the complexity and heterogenicity of patients presenting with MAC, consensus on several key recommendations was reached by this American Association for Thoracic Surgery expert panel. These recommendations provide guidance for cardiac surgeons and structural heart interventionists in treating most patients who present with MAC.

LAMPOON Technique and Transapical Wire Externalization During Transcatheter Mitral Valve Replacement

A 74-year-old woman with failed mitral surgical repair underwent transcatheter mitral valve-in-ring replacement. Pre-procedural assessment highlighted a substantial risk for valve misalignment and left ventricular outflow obstruction. Electrosurgical laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) technique and transapical wire externalization for valve deployment were successfully employed to prevent these complications.

The posterior mitral leaflet overhang: A rare yet possible complication of percutaneous mitral valve procedures

The two surgical options for mitral valve regurgitation are replacement and repair, with annuloplasty being the cornerstone of correction. In cases of repair failure, especially in high surgical risk patients, transcatheter mitral valve-in-ring (MViR) procedures represent emerging and challenging options. Among the several complications linked to this treatment, this paper delves into the role that native mitral leaflets may play in precipitating acute bioprosthesis dysfunction in the MViR procedure. The literature extensively covers complications related to the anterior leaflet, including risks such as outflow tract obstruction and residual mitral insufficiency due to interaction between native and prosthetic leaflets. Conversely, complications involving the posterior leaflet are less understood and often overlooked. In this gap in the literature, we present a clinical case highlighting how a redundant native posterior mitral leaflet can unexpectedly lead to acute severe mitral insufficiency by interfering with prosthetic leaflets.

Direct Implantation of Transcatheter Valve in Mitral Annular Calcification: A Multicenter Study

BACKGROUND

Mitral valve replacement in the setting of severe annular calcification (MAC) is associated with high morbidity and mortality. Direct surgical implantation of a transcatheter heart valve (THV) through a transatrial approach is a strategy to mitigate surgical risk. This study reports the perioperative and 1-year outcomes of mitral valve replacement using a THV in patients with severe circumferential MAC at 3 Canadian centers.

METHODS

Charts were reviewed between January 1, 2018 and September 30, 2023 to identify patients with severe circumferential MAC who had undergone direct implantation of a THV. Primary outcomes were 30-day mortality, debilitating stroke, and 1-year mortality. Secondary outcomes included left ventricular outflow tract obstruction, degree of paravalvular leak (PVL), transvalvular mean pressure gradient, and length of stay.

RESULTS

Twenty-two patients at the 3 centers underwent direct implantation of a THV. Nineteen patients were female, with mean age of 70.41 ± 9.33 years. A THV was successfully implanted in all patients. There were 2 deaths at 30 days. Four patients died of noncardiac causes at 1 year, and 1 patient had a postoperative stroke. Seventeen (77%) patients had no PVL or trace PVL, 4 had mild PVL, and 1 patient had mild-moderate PVL. The mean transvalvular gradient was 4.42 ± 4.40 mm Hg. There were no cases of left ventricular outflow tract obstruction.

CONCLUSIONS

Direct deployment of a THV in patients with severe MAC may be a reasonable option. Thirty-day and 1-year mortality rates of 9% and 18%, respectively, suggest that this approach should be reserved for high-risk patients who are not able to undergo conventional strategies.

5-Year Outcomes of Anterior Mitral Leaflet Laceration to Prevent Outflow Obstruction

BACKGROUND

Left ventricular outflow tract (LVOT) obstruction is a common, often fatal complication of transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) was safe and effective at preventing LVOT obstruction at 30 days in the National Heart, Lung, and Blood Institute LAMPOON trial.

OBJECTIVES

The authors report the 5-year outcomes of intentional anterior mitral leaflet laceration before SAPIEN 3 TMVR, in patients at risk of LVOT obstruction.

METHODS

The National Heart, Lung, and Blood Institute LAMPOON trial was a prospective, multicenter, single-arm safety and feasibility study of LAMPOON and transseptal SAPIEN 3 TMVR in annuloplasty rings (valve-in-ring) or native mitral annular calcification (MAC) (valve-in-MAC). All subjects had high predicted risk for LVOT obstruction. Subjects were not excluded for excessive frailty or comorbidity. The primary endpoints were technical success and safety at 30 days. Secondary clinical and echocardiographic endpoints were assessed at 1 year and clinical follow-up at 5 years.

RESULTS

Thirty subjects were enrolled between June 2017 and June 2018, equally between the valve-in-MAC and valve-in-ring arms. At 30 days, LAMPOON was successful in all 30 subjects, with no strokes, 1 (3%) death, and 1 (3%) moderate LVOT obstruction. Eighteen (65%) survived to 1 year, and 7 (25%) survived to 5 years. Six (20%) were hospitalized for heart failure in the first year. From baseline to 1 year, there was a 24-point improvement in Kansas City Cardiomyopathy Questionnaire score and a 60-m improvement in 6-minute walk distance. There was no significant change in N-terminal pro-brain natriuretic peptide. At 1 year, LVOT gradients remained low.

CONCLUSIONS

LAMPOON enabled TMVR despite the risk for LVOT obstruction. There were no long-term complications associated with LAMPOON. The selection of inoperable patients limited assessment of long-term survival following TMVR. (NHLBI DIR LAMPOON Study: Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Implantation; NCT03015194).

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.

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 in Failed Bioprosthetic Valve, Ring, and Mitral Annular Calcification Associated Mitral Valve Disease Using Balloon Expandable Transcatheter Heart Valve

Transcatheter mitral valve replacement (TMVR) using the SAPIEN platform has been performed in failed bioprosthetic valves (valve-in-valve), surgical annuloplasty rings (valve-in-ring), and native valves with mitral annular calcification (MAC) (valve-in-MAC). Experience over the past decade has identified important challenges and solutions to improve clinical outcomes. In this review, we discuss the indication, trend in utilization, unique challenges, procedural planning, and clinical outcomes of valve-in-valve, valve-in-ring, and valve-in-MAC TMVR.

Role of Cardiac Computed Tomography in Planning Transcatheter Mitral Valve Replacement (TMVR)

PURPOSE OF REVIEW

Transcatheter mitral valve replacement (TMVR) is an evolving and rapidly expanding field within structural interventions, offering renewed treatment options for patients with high-risk mitral valve disease. We aim to highlight and illustrate the importance of cardiac CT in the planning of TMVR.

RECENT FINDINGS

As TMVR has evolved, so has the specific nuances of cardiac CT planning, we now understand the importance of accurate annular sizing and valve simulation to predict complications such as neo-LVOT obstruction and paravalvular leak (PVL). More so than any other modality, cardiac CT remains instrumental in accurately planning TVMR from feasibility, device sizing, access, and fluoroscopic angles. Cardiac CT remains the key modality in TMVR evaluation, often the first step in determining patient eligibility through comprehensive procedural planning as well as informing potential outcomes and prognosis. In this review, we discuss the critical role of cardiac computed tomography (CT) and the specific considerations involved in TMVR.

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.

Real-world experience with concomitant or staged transcatheter aortic and mitral valve replacements using balloon-expandable valves

OBJECTIVE

To describe outcomes of patients who underwent transcatheter aortic valve replacement (TAVR) in a native valve or failed bioprosthetic valve or transcatheter heart valve (THV) and a transcatheter mitral valve replacement procedure (TMVR; valve-in-valve [mViV], valve-in-ring [mViR], and valve in mitral annulus calcification [ViMAC]) either concomitantly (same procedure) or staged (different procedures).

BACKGROUND

Patient characteristics, procedural details, and outcomes of concomitant or staged TAVR and TMVR procedures are largely unknown.

METHODS

Data were extracted from the STS/ACC TVT Registry™ for patients undergoing concomitant or staged TAVR and TMVR with SAPIEN XT, SAPIEN 3, or SAPIEN 3 Ultra (Edwards Lifesciences) THVs. Descriptive results were reported for procedural, index hospitalization, 30-day, and 1-year outcomes.

RESULTS

A total of 257 patients underwent TAVR and TMVR in concomitant (n = 135) or staged (n = 122) procedures. Device success was 82.9% and 83.9% for concomitant TAVR and TMVR procedures and 83.8% and 82.5% for staged TAVR and TMVR procedures. Significant improvements in aortic and mitral valve function remained stable through 1 year. All-cause mortality for concomitant and staged groups was 14.7% and 10.5% at 30 days, and 32.8% and 24.6% at 1 year, respectively. Stroke rate for concomitant and staged groups was 0.8% and 3.6% at 30 days and 3.9% and 5.6% at 1 year, respectively. Improvements from baseline to 1 year in NYHA class and KCCQ overall summary scores were observed for all patients.

CONCLUSIONS

Concomitant or staged transcatheter treatment of patients with aortic and mitral valve disease can be performed in select high-risk patients in experienced centers.

Assessing the Hemodynamic Impact of Anterior Leaflet Laceration in Transcatheter Mitral Valve Replacement: An in silico Study

Background

A clinical study comparing the hemodynamic outcomes of transcatheter mitral valve replacement (TMVR) with vs. without Laceration of the Anterior Mitral leaflet to Prevent Outflow Obstruction (LAMPOON) has never been designed nor conducted.

Aims

To quantify the hemodynamic impact of LAMPOON in TMVR using patient-specific computational (in silico) models.

Materials

Eight subjects from the LAMPOON investigational device exemption trial were included who had acceptable computed tomography (CT) data for analysis. All subjects were anticipated to be at prohibitive risk of left ventricular outflow tract (LVOT) obstruction from TMVR, and underwent successful LAMPOON immediately followed by TMVR. Using post-procedure CT scans, two 3D anatomical models were created for each subject: (1) TMVR with LAMPOON (performed procedure), and (2) TMVR without LAMPOON (virtual control). A validated computational fluid dynamics (CFD) paradigm was then used to simulate the hemodynamic outcomes for each condition.

Results

LAMPOON exposed on average 2 ± 0.6 transcatheter valve cells (70 ± 20 mm² total increase in outflow area) which provided an additional pathway for flow into the LVOT. As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak LVOT velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 0.4 ± 0.3 m/s (14 ± 7% improvement, p = 0.006), 7.6 ± 10.9 mmHg (31 ± 17% improvement, p = 0.01), and 0.2 ± 0.1 cm² (17 ± 9% improvement, p = 0.002), respectively.

Conclusion

This was the first study to permit a quantitative, patient-specific comparison of LVOT hemodynamics following TMVR with and without LAMPOON. The LAMPOON procedure achieved a critical increment in outflow area which was effective for improving LVOT hemodynamics, particularly for subjects with a small neo-left ventricular outflow tract (neo-LVOT).

Imaging in Transcatheter Mitral Valve Replacement: State-of-Art Review

Mitral regurgitation is the second-most frequent valvular heart disease in Europe and it is associated with high morbidity and mortality. Recognition of MR should encourage the assessment of its etiology, severity, and mechanism in order to determine the best therapeutic approach. Mitral valve surgery constitutes the first-line therapy; however, transcatheter procedures have emerged as an alternative option to treat inoperable and high-risk surgical patients. In patients with suitable anatomy, the transcatheter edge-to-edge mitral leaflet repair is the most frequently applied procedure. In non-reparable patients, transcatheter mitral valve replacement (TMVR) has appeared as a promising intervention. Thus, currently TMVR represents a new treatment option for inoperable or high-risk patients with degenerated or failed bioprosthetic valves (valve-in-valve); failed repairs, (valve-in-ring); inoperable or high-risk patients with native mitral valve anatomy, or those with severe annular calcifications, or valve-in-mitral annular calcification. The patient selection requires multimodality imaging pre-procedural planning to select the best approach and device, study the anatomical landing zone and assess the risk of left ventricular outflow tract obstruction. In the present review, we aimed to highlight the main considerations for TMVR planning from an imaging perspective; before, during, and after TMVR.