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Metrics for defining LVOT obstruction based on pressure gradient and systolic flow rate. LVOT EOA allows for incorporation of systolic flow rate into the definition of LVOT obstruction. CT, computed tomography; EOA, effective orifice area; LVOT, left ventricular outflow tract; PAo, aortic pressure; PLV, left ventricular pressure; Qmean, mean systolic flow rate; vmean, mean outflow velocity.
Source publication
Aims
To characterize the dynamic nature of the left ventricular outflow tract (LVOT) geometry and flow rate in patients following transcatheter mitral valve replacement (TMVR) with anterior leaflet laceration (LAMPOON) and derive insights to help guide future patient selection.
Methods and results
Time-resolved LVOT geometry and haemodynamics were...
Citations
... LVOT obstruction is conventionally defined as an increase in LVOT gradient by 10 mmHg, although a clinical impact is more likely evident when the gradient increases by more than 30 mmHg [74,75]. Two principal mechanisms have been described. ...
Transcatheter aortic valve implantation (TAVI) is now well established as the treatment of choice for patients with native aortic valve stenosis who are high or intermediate risk for surgical aortic valve replacement. Recent data has also supported the use of TAVI in patients at low surgical risk and also in anatomical subsets that were previously felt to be contra-indicated including bicuspid aortic valves and aortic regurgitation. With advancements and refinements in procedural techniques, the application of this technology has now been further expanded to include the management of degenerated bioprosthesis. After the demonstration of feasibility and safety in the management of degenerated aortic bioprosthetic valves, mitral and tricuspid bioprosthetic valve treatment is now also well-established and provides an attractive alternative to performing redo surgery. In this review, we appraise the latest clinical evidence and highlight procedural considerations when utilising TAVI technology in the management of degenerated aortic, mitral or tricuspid prosthesis.
... Finally, several articles have provided important information on the results of novel trans-catheter therapies and highlighted the role of intra-procedural imaging to achieve optimal results. [56][57][58] Mitral annular calcification is an important factor that may impact negatively on the results of several surgical and trans-catheter therapies of mitral valve dysfunction and on the outcomes of the patients. The role of multimodality imaging to define and classify the severity of mitral annulus calcification derived from echocardiography and computed tomography as well as the therapeutic options available was summarized in a comprehensive review article. ...
The European Heart Journal—Cardiovascular Imaging with its over 10 years existence is an established leading multi-modality cardiovascular imaging journal. Pertinent publications including original research, how-to papers, reviews, consensus documents, and in our journal from 2022 have been highlighted in two reports. Part I focuses on cardiomyopathies, heart failure, valvular heart disease, and congenital heart disease and related emerging techniques and technologies.
... 39,40,42 With a safety margin, a neo-LVOT area ≥ 200 mm 2 is considered safe to perform TMVR without additional intervention. When a modification to the anterior leaflet (known as LAMPOON, or laceration of the anterior mitral valve leaflet to prevent LVOT obstruction) 44 is performed to prevent LVOT obstruction, the neo-LVOT shifts towards the base of the implanted valve at the level of the SAPIEN skirt, creating "skirt" neo-LVOT (Figure 2). A skirt neo-LVOT < 150 mm 2 to 180 mm 2 may still produce LVOT obstruction despite a successful LAMPOON. ...
... A skirt neo-LVOT < 150 mm 2 to 180 mm 2 may still produce LVOT obstruction despite a successful LAMPOON. 43,44 A more simplified measurement of the distance from the distal edge of the virtual valve to the basal septum with a cutoff < 5.5 mm also appears to be a predictor of LVOT obstruction (Figure 2). 39 Although anterior mitral leaflet length alone has not been reported as an independent risk factor for LVOT obstruction, cases of overhanging leaflets causing central mitral regurgitation through leaflet interference or dynamic LVOT obstruction via the Venturi effect have been observed when leaflet length is longer than the SAPIEN valve height. ...
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.
... While the residual skirt neo-LVOT area required to avoid LVOTO is ~ 200-250 mm 2 and a commonly accepted margin of safety [17••, 18•], this threshold is phasespecific and the neo-LVOT can change from early systole to end systole. Measurements at peak systolic flow may represent a step toward a more physiological prediction of LVOTO [19]. Since the AML is part of the neo-LVOT, AML length and anatomy are variables relevant to LVOTO. ...
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.
Summary
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.
... However, despite this improvement, this subject still had a 30 mmHg simulated LVOT gradient post-LAMPOON due to a small skirt neo-LVOT area (162 mm 2 ). While initial clinical data suggested a skirt neo-LVOT area of <150 mm 2 should be avoided to prevent significant LVOT obstruction (catheterization gradient >30 mmHg), a more recent study from our group has shown that a skirt neo-LVOT area >180 mm 2 is ideal to ensure survival with measurable clinical benefit (e.g., improvement in Kansas City Cardiomyopathy Questionnaire Score) (9). Thus, flow simulations in this study corroborate the clinical observation that LVOT obstruction may still occur following LAMPOON in the case of a small skirt neo-LVOT, and confirm that the skirt neo-LVOT should be routinely and carefully evaluated prior to performing TMVR with LAMPOON. ...
BackgroundA 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.AimsTo quantify the hemodynamic impact of LAMPOON in TMVR using patient-specific computational (in silico) models.MaterialsEight 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.ResultsLAMPOON 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).
Background
Left Ventricular Outflow 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 left ventricular outflow tract (LVOT) and a D-shaped deformation of the bioprosthetic valve.
Case summary
A 64-year-old female presented with acute pulmonary oedema two 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 (ViMAC) TMVR by balloon inflation in the LVOT. It is strongly recommended to place a “rescue” guidewire in trans-aortic position during TMVR in order to manage the potential onset of acute LVOTO.
