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).

A novel method of prosthetic leaflet modification to enable transcatheter mitral valve-in-valve replacement.

Left ventricular outflow tract (LVOT) obstruction from the displaced prosthetic anterior mitral leaflet is a life-threatening complication that can occur during valve-in-valve (ViV) transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction is a well-established transcatheter technique to mitigate the risk of LVOT obstruction in high-risk anatomies. In this report, we present a novel transseptal technique of prosthetic leaflet modification to prevent LVOT obstruction during ViV TMVR.

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.

CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR). / CT-Planung vor kathetergestütztem Mitralklappenersatz (TMVR).

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a treatment option for patients with therapy refractory high-grade mitral valve regurgitation and a high perioperative risk.During TMVR, the mitral annulus cannot be visualized directly. Therefore, comprehensive pre-interventional planning and a precise visualization of the patient's specific mitral valve anatomy, outflow tract anatomy and projected anchoring of the device are necessary.Aim of this review-article is, to assess the role of pre-procedural computed tomography (CT) for TMVR-planning METHODS: Screening and evaluation of relevant guidelines (European Society of Cardiology [ESC], American Heart Association [AHA/ACC]), meta-analyses and original research using the search terms "TVMR" or "TMVI" and "CT". In addition to this, the authors included insight from their own clinical experience. RESULTS: CT allows for accurate measurement of the mitral annulus with high special and adequate temporal resolution in all cardiac phases. Therefore, CT represents a valuable method for accurate prosthesis-sizing.In addition to that, CT can provide information about the valvular- and outflow-tract-anatomy, mitral valve calcifications, configuration of the papillary muscles and of the left ventricle. Additionally, the interventional access-route may concomitantly be visualized. CONCLUSION: CT plays, in addition to echocardiographic imaging, a central role in pre-interventional assessment prior to TMVR. Especially the precise depiction of the left ventricular outflow tract (LVOT) provides relevant additional information, which is very difficult or not possible to be acquired in their entirety with other imaging modalities. KEY POINTS: · CT plays a central role in pre-interventional imaging for TMVR.. · CT-measurements allow for accurate prosthesis-sizing.. · CT provides valuable information about LVOT-anatomy, mitral calcifications and interventional access-route.. CITATION FORMAT: · Heiser L, Gohmann RF, Noack T et al. CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR). Fortschr Röntgenstr 2022; 194: 373 - 383.

Genetic and Developmental Contributors to Aortic Stenosis.

Aortic stenosis (AS) remains one of the most common forms of valve disease, with significant impact on patient survival. The disease is characterized by left ventricular outflow obstruction and encompasses a series of stenotic lesions starting from the left ventricular outflow tract to the descending aorta. Obstructions may be subvalvar, valvar, or supravalvar and can be present at birth (congenital) or acquired later in life. Bicuspid aortic valve, whereby the aortic valve forms with two instead of three cusps, is the most common cause of AS in younger patients due to primary anatomic narrowing of the valve. In addition, the secondary onset of premature calcification, likely induced by altered hemodynamics, further obstructs left ventricular outflow in bicuspid aortic valve patients. In adults, degenerative AS involves progressive calcification of an anatomically normal, tricuspid aortic valve and is attributed to lifelong exposure to multifactoral risk factors and physiological wear-and-tear that negatively impacts valve structure-function relationships. AS continues to be the most frequent valvular disease that requires intervention, and aortic valve replacement is the standard treatment for patients with severe or symptomatic AS. While the positive impacts of surgical interventions are well documented, the financial burden, the potential need for repeated procedures, and operative risks are substantial. In addition, the clinical management of asymptomatic patients remains controversial. Therefore, there is a critical need to develop alternative approaches to prevent the progression of left ventricular outflow obstruction, especially in valvar lesions. This review summarizes our current understandings of AS cause; beginning with developmental origins of congenital valve disease, and leading into the multifactorial nature of AS in the adult population.

Antegrade Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction: A Simplified Technique From Bench to Bedside.

BACKGROUND: Intentional laceration of the anterior mitral leaflet (LAMPOON) is an effective adjunct to transcatheter mitral valve replacement that prevents left ventricular outflow tract (LVOT) obstruction. To date, LAMPOON has been performed in over 150 patients using a retrograde approach that can be technically challenging. A modified antegrade transseptal technique may simplify the procedure. METHODS: Antegrade LAMPOON was developed and tested in nonsurvival pig experiments. Thereafter, antegrade LAMPOON was performed in patients at prohibitive risk of LVOT obstruction. Clinical, procedural, and angiographic details were abstracted from medical records of their index procedure, and were compared with findings in comparable patients at risk of fixed-LVOT obstruction in the LAMPOON investigational device exemption trial. RESULTS: Eight patients at risk of fixed LVOT obstruction underwent antegrade LAMPOON. Leaflet traversal and laceration were technically successful in all. There were no cases of clinically significant LVOT obstruction (mean LVOT gradient at discharge: 5.4±1.4 mm Hg). One patient suffered a ventricular wire perforation, unrelated to the antegrade LAMPOON technique, and did not survive to discharge. At the time of discharge, no patients had an increase of >10 mm Hg in LVOT gradient compared with baseline. Procedure times (from traversal to transcatheter mitral valve replacement) were shorter, compared with the retrograde technique in the LAMPOON investigational device exemption trial (39±09 versus 65±35 minutes). All patients survived (8/8, 100%) the procedure, and 7/8 (88%) survived to 30 days, similar to subjects in the LAMPOON investigational device exemption trial. CONCLUSIONS: Antegrade LAMPOON is an effective, reproducible, and simplified strategy to lacerate the anterior leaflet before transcatheter mitral valve replacement. The authors recommend the technique as the new standard for LAMPOON.

Sequential Use of Alcohol Septal Ablation and Electrosurgical Leaflet Resection Prior to Transcatheter Mitral Valve Replacement.

In patients with increased surgical risk and hemodynamically significant mitral disease, a transcatheter strategy for mitral valve replacement (TMVR) may be suitable; however, is also not without procedure risk. Obstruction of the left ventricular outflow tract (LVOT) is one of the most dreaded complications of TMVR, requiring careful consideration of potential candidates with preprocedural imaging and ex vivo valvular fit simulation as part of risk assessment for postprocedure obstruction. In patients at high risk of LVOT obstruction, early studies have shown that alcohol septal ablation or electrosurgical laceration of the anterior mitral leaflet (LAMPOON) procedure prior to TMVR may mitigate the risk of LVOT obstruction. We describe the recent successful management of a patient with severe mitral valve disease, mitral annular calcification (MAC), and high risk of post-TMVR LVOT obstruction, who underwent a sequential strategy of ASA followed by electrosurgical leaflet resection with the LAMPOON procedure prior to TMVR to successfully prevent LVOT obstruction. To our knowledge, this is the first time this dual strategy has been reported, and it may allow more patients with severe mitral valve disease to undergo TMVR in the future.

Balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction (BATMAN): A novel technique for patients undergoing transcatheter mitral valve replacement.

INTRODUCTION: Transcatheter mitral valve replacement (TMVR) is an option for patients at high risk for mitral valve replacement or repair via sternotomy or left thoracotomy approach. TMVR carries up to 22% risk of left ventricular outflow tract (LVOT) obstruction. Severe LVOT obstruction can have devastating hemodynamic and clinical consequences. HYPOTHESIS: We previously presented a novel technique to prevent LVOT obstruction during transapical retrograde mitral valve replacement, by penetrating and ballooning the anterior mitral leaflet (AML), resulting in creation of a "hole" and posterior translocation of AML, then deploying the valve. METHODS: Three patients underwent TMVR at Saint Louis University for severe mitral regurgitation after being deemed too high risk for surgery, and not candidates for a Mitra-clip procedure. These patients were deemed to be at risk for LVOT obstruction based on the preprocedural evaluation. Via transapical approach, a needle was advanced "through," perforating the AML and wire was placed in the left atrium. Over the wire, an 20-mm valvuloplasty balloon was positioned "within" the anterior leaflet and inflated leading to translocation of the AMVL. Then the valve was deployed. RESULTS: This novel technique has been performed on three patients at our institution. Sapien S3 transcatheter valves were used in all three patients, with 100% procedural success rate. Intraoperative TEE demonstrated no significant LVOT obstruction, cardiopulmonary bypass time was 42-44 min. CONCLUSION: The balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction technique described here may offer the option of transcatheter mitral valve implantation in patients at high risk of LVOT obstruction. A variation of this technique to allow application in cases with transseptal approach is under investigation.

Preemptive Alcohol Septal Ablation to Prevent Left Ventricular Outflow Tract Obstruction after Transseptal Mitral Valve in Valve.

Acute obstruction of the neo-LVOT is a major and potentially fatal complication of transcatheter mitral valve implantation. Patients at high risk of this complication can be identified preoperatively with cardiac CT. We describe a case of a patient identified as high risk for developing neo-LVOT obstruction, who was preemptively treated with alcohol septal ablation prior to successful valve implantation.

Septal ablation acutely reduces outflow obstruction after transcatheter mitral valve replacement.

Transcatheter mitral valve replacement (TMVR) is an emerging treatment of mitral valve pathology in patients that are not candidates for conventional surgical approaches. Higher rates of left ventricular outflow tract obstruction (LVOTO) may occur following TMVR and its occurrence is an independent predictor of mortality. We present a case of severe mitral stenosis and annular calcification that was treated with a balloon-expandable Sapien S3 valve in the mitral position delivered through surgical port-access approach, which resulted in postoperative LVOTO. The LVOTO was successfully treated with alcohol septal ablation with immediate reduction in outflow tract gradients and long-term resolution.

Alcohol Septal Ablation to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Replacement: First-in-Man Study.

OBJECTIVES: This study evaluates outcomes of pre-emptive alcohol septal ablation (ASA) to prevent iatrogenic left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR). BACKGROUND: LVOT obstruction is a life-threatening complication of TMVR. Bail-out ASA has been described as a therapeutic option for patients with outflow obstruction during TMVR, but little is known about pre-emptive ASA. METHODS: Multicenter registry of patients with severe mitral valve disease who underwent pre-emptive ASA to mitigate LVOT obstruction risk after TMVR. High risk of LVOT obstruction was predicted in all patients by pre-procedural computed tomographic imaging. RESULTS: Thirty patients (age 76.1 ± 7.7 years; women 76.7%) with severe mitral valve disease underwent pre-emptive ASA to mitigate TMVR-induced LVOT obstruction risk. Twenty patients underwent mitral valve replacement (14 transseptal, 3 transatrial, 1 transapical, 1 transseptal with percutaneous laceration of anterior mitral leaflet, 1 treated with surgical mitral valve replacement). Eight patients experienced clinical improvement post-ASA. Two patients died before TMVR. Median increase in neo-LVOT surface area post-ASA was 111.2 mm2 (interquartile range: 71.4 to 193.1 mm2). Five patients (16.7%) required pacemaker implantation post-ASA. In-hospital and 30-day mortality post-ASA was 6.7% (2/30 patients). After ASA, TMVR was performed successfully in 100% of attempted cases. In-hospital and 30-day mortality post-TMVR was 5.3% (1/19). Mortality of entire cohort was 10% (3/30 patients: 2 post-ASA before TMVR, 1 died 30 days post-TMVR). CONCLUSIONS: Pre-emptive ASA is associated with a significant increase in predicted neo-LVOT area before TMVR and may enable safe TMVR in patients usually excluded secondary to prohibitive risk of LVOT obstruction.

Anterior Leaflet Laceration to Prevent Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Replacement.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is a leading cause of mortality and exclusion from transcatheter mitral valve replacement (TMVR). Intentional laceration of the anterior mitral valve leaflet to prevent LVOT obstruction (LAMPOON) is a transcatheter mimic of surgical chord-sparing leaflet resection. OBJECTIVES: The purpose of this prospective multicenter trial was to study LAMPOON with transseptal (Edwards Lifesciences, Irvine, California) TMVR in annuloplasty rings or native mitral annular calcification (MAC). METHODS: Subjects at high or extreme surgical risk and prohibitive risk of LVOT obstruction from TMVR were included. Eligibility was modified midtrial to exclude subjects with threatened LVOT obstruction from a Sapien 3 valve fabric skirt. The primary endpoint was procedure survival with successful LAMPOON, with successful TMVR, without reintervention, and with LVOT gradient <30 mm Hg ("optimal") or <50 mm Hg ("acceptable"). Secondary endpoints included 30-day mortality and major adverse cardiovascular events. There was universal source-data verification and independent monitoring. All endpoints were independently adjudicated. Central laboratories analyzed echocardiogram and CT images. RESULTS: Between June 2017 and June 2018, 30 subjects were enrolled equally between the MAC and ring arms. LAMPOON traversal and midline laceration was successful in 100%. Procedure survival was 100%, and 30-day survival was 93%. Primary success was achieved in 73%, driven by additional procedures for paravalvular leak (10%) and high-skirt neo-LVOT gradients observed before a protocol amendment. There were no strokes. CONCLUSIONS: LAMPOON was feasible in native and annuloplasty ring anatomies in patients who were otherwise ineligible for treatment, with acceptable safety. LAMPOON was effective in preventing LVOT obstruction from TMVR. Despite LAMPOON, TMVR using Sapien 3 in annuloplasty rings and MAC still exhibits important limitations. (NHLBI DIR LAMPOON Study: Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Implantation; NCT03015194).

Robotic Septal Myectomy Without Anterior Leaflet Incision during Mitral Valve Repair.

Bulging subaortic septum in hypertrophic cardiomyopathy is a potential risk factor for systolic anterior motion after mitral valve repair. Systolic anterior motion may cause postoperative mitral regurgitation and left ventricular outflow tract obstruction despite conservative management. During "minimally invasive endoscopic" and "robotic" mitral repair procedures, systolic anterior motion is prevented with concomitant septal myectomy through the mitral valve orifice. Technically, the exposure of the bulging subaortic septum is traditionally done with detachment of the anterior mitral leaflet from its annulus, leaving a 2-mm rim of leaflet attached to the annulus. The leaflet is then sutured after myectomy. As an alternative technique in robotic surgery, the exposure of the subaortic septum is feasible without anterior leaflet incision with the use of dynamic atrial retractor in mitral repair procedures. Here, we present a patient who underwent concomitant robotic mitral valve repair with posterior chordal implantation, ring annuloplasty, and septal myectomy without anterior leaflet incision using the da Vinci surgical system.

Left Ventricular Outflow Tract Obstruction: A Potential Obstacle for Transcatheter Mitral Valve Therapy.

Transcatheter mitral valve replacement is the focus of much enthusiasm as the future of therapy for mitral valve disease. Despite technological advances, left ventricular outflow tract (LVOT) obstruction from the valve prosthesis remains an important issue. In this review the authors discuss the pathophysiology of LVOT obstruction in both the surgical and transcatheter experience, imaging evaluation preprocedure, outcomes to date, and therapeutic options.

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.

Surgical Transatrial Implantation of Transcatheter Heart Valves in Severe Mitral Annular Calcification.

Surgical mitral valve replacement in patients with severe annular calcification is a challenge for the cardiac surgeon. Surgical transatrial implantation of a transcatheter heart valve is an alternative for selected patients, in particular those at risk for obstruction of the left ventricular outflow tract or valve embolization. Herein, we review patient selection, surgical technique, and early outcomes after this novel hybrid procedure.