Background: Leaflet thrombosis after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) may be caused by blood flow stagnation in the native and neosinus regions. To date, aortic leaflet laceration has been used to mitigate coronary obstruction following TAVR; however, its influence on the fluid mechanics of the native and neosinus regions is poorly under-stood. This in vitro study compared the flow velocities and flow patterns in the setting of SAVR vs TAVR with and without aortic leaflet lacerations.Methods: Two valves, (23-mm Perimount and 26-mm SAPIEN 3; Edwards Lifesciences) were studied in a validated mock flow loop under physiologic conditions. Neo -sinus and native sinus fluid mechanics were quantified using particle image velocimetry in the left and noncoronary cusp, with an increasing number of aortic leaflets lacerated or removed.Results: Across all conditions, SAVR had the highest average sinus and neosinus velocities, and this value was used as a reference to compare against the TAVR conditions. With an increasing number of leaflets lacerated or removed with TAVR, the average sinus and neosinus velocities increased from 25% to 70% of SAVR flow (100%). Diastolic velocities were substantially augmented by leaflet laceration. Also, the shorter frame of the SAVR led to higher flow velocities compared with the longer frame of the TAVR, even after complete leaflet removal.Conclusions: Leaflet laceration augmented TAVR native and neosinus flowfields, approaching that of SAVR. These findings may have potential clinical implications for the use of single or multiple leaflet lacerations to reduce leaflet thrombosis and thus potentially improve TAVR durability.

A number of devices are available in early investigation or development to treat tricuspid regurgitation (TR) percutaneously, using different methods targeted at the underlying etiology of TR. MitraClip (Abbott Vascular) and PASCAL (Edwards Lifesciences) are 2 devices used for transcatheter edge-to-edge repair (TEER) to treat leaflet malcoaptation.Transesophageal echocardiography (TEE) remains the mainstay of diagnosis and evaluation of TR and for procedural guidance. Intraprocedural imaging for tricuspid valve (TV) TEER can be challenging due to shadowing from the aortic valve, the mitral valve, and/or the interatrial septum in the esophageal and transgastric views can be unpredictable. This can result in a severely limited ability to visualize the important components of the procedure (leaflet grasping, clip orientation, etc.) while using a TEER device, especially when device delivery equipment, such as catheters, further obscure visualization. Intracardiac echocardiography (ICE), with the probe placed directly into the right atrium, allows the operator to view the TV without any interference from other cardiac structures. Using ICE to confirm leaflet grasping in conjunction with TEE has been previously described.1Müller K. Jorbenadze R. Walker T. et al.Percutaneous transfemoral tricuspid valve edge-to-edge repair: a case series.Circ Heart Fail. 2017; 10e003965Crossref Scopus (3) Google Scholar Other strategies have included placing a pediatric TEE probe into a sterile sheath and placing that into the right atrium for procedural guidance.2Robinson A.A. Chadwell K. Fowler D.E. Ailawadi G. Lim D.S. Multiplane intracardiac echocardiography: a novel system to guide percutaneous tricuspid repair.JACC Cardiovasc Interv. 2018; 11: 2540-2542Crossref PubMed Scopus (6) Google Scholar Traditional ICE catheters used for structural heart procedures use phased array transducers and have several limitations, including poor far field visualization, instability of the ICE catheter in the right atrium or ventricle, and inability to manipulate the catheter in all directions.3Hahn R.T. Nabauer M. Zuber M. et al.Intraprocedural imaging of transcatheter tricuspid valve interventions.JACC Cardiovasc Imaging. 2019; 12: 532-553Crossref PubMed Scopus (40) Google Scholar The placement of a pediatric TEE probe into the right atrium overcomes some of these issues but is limited by the large bore venous access needed and possible sterility issues if the sterile probe cover were to become disrupted. A potential solution has been the development of 3-dimensional ICE catheters (which has improved sector angle range, biplane, and 3-dimensional functionality); however, currently, these are not widely available for clinical use.To overcome some of these limitations of the ICE catheter, we placed an ICE catheter (ViewFlex, St. Jude Medical) inside a 9F steerable sheath (FlexCath, Medtronic; Figure 1). This combination improves catheter stability when imaging near-field tricuspid structures. With this configuration, the operator has increased stability of the ICE catheter and added rotation to view the TV apparatus and leaflet grasping. The outer catheter allows for the inner ICE catheter to independently rotate around its central axis to image in multiple planes as opposed to making wide circular motions with ICE while not using a steerable catheter. In our experience, the operator is also able to obtain more acute bends of the catheter in most cases. We have performed 31 TV TEER since 2018, with 18 procedures performed using this technique in patients with suboptimal TEE windows.Tricuspid valve visualization and successful TEER were accomplished in all cases (18 of 18 cases). Compared with the procedure times in cases using only TEE, cases requiring ICE had longer procedure times (159.4 min vs 220.0 min; P = .006) and longer fluoroscopy times (42.5 min vs 99.1 min; P = .0005). Between cases using traditional TEE and those using ICE, there was no significant difference in the number of clips placed (1.7 vs 1.5; P = .57), single leaflet detachment (2 vs 0, P = .17), or the median grade of TR reduction (2.0 vs 2.0; P = .14; Figure 1).Intraprocedural imaging is paramount to the effectiveness of TEER, with poor quality or inadequate visualization leading to less effective treatment and potential morbidity for patients. The use of ICE lengthens procedural and fluoroscopy time because these cases are mired by difficulty with visualization of leaflet grasping by TEE. As a result, with the addition of ICE, there is increased complexity to confirm device position and leaflet insertion when applying both imaging modalities together in addition to the procedural aspect of getting ICE into position, generally leading to increased procedural times. Despite increased procedure times, our limited cohort with baseline suboptimal imaging by TEE alone benefited from the enhanced visualization by ICE inside a steerable catheter for successful TEER without complications associated with the ICE catheter.In patients who are eligible for TV TEER but have limited visualization of TV leaflets by TEE, multimodality imaging with the addition of an ICE catheter placed inside a steerable catheter is a safe and useful adjunct to TV TEER. A number of devices are available in early investigation or development to treat tricuspid regurgitation (TR) percutaneously, using different methods targeted at the underlying etiology of TR. MitraClip (Abbott Vascular) and PASCAL (Edwards Lifesciences) are 2 devices used for transcatheter edge-to-edge repair (TEER) to treat leaflet malcoaptation. Transesophageal echocardiography (TEE) remains the mainstay of diagnosis and evaluation of TR and for procedural guidance. Intraprocedural imaging for tricuspid valve (TV) TEER can be challenging due to shadowing from the aortic valve, the mitral valve, and/or the interatrial septum in the esophageal and transgastric views can be unpredictable. This can result in a severely limited ability to visualize the important components of the procedure (leaflet grasping, clip orientation, etc.) while using a TEER device, especially when device delivery equipment, such as catheters, further obscure visualization. Intracardiac echocardiography (ICE), with the probe placed directly into the right atrium, allows the operator to view the TV without any interference from other cardiac structures. Using ICE to confirm leaflet grasping in conjunction with TEE has been previously described.1Müller K. Jorbenadze R. Walker T. et al.Percutaneous transfemoral tricuspid valve edge-to-edge repair: a case series.Circ Heart Fail. 2017; 10e003965Crossref Scopus (3) Google Scholar Other strategies have included placing a pediatric TEE probe into a sterile sheath and placing that into the right atrium for procedural guidance.2Robinson A.A. Chadwell K. Fowler D.E. Ailawadi G. Lim D.S. Multiplane intracardiac echocardiography: a novel system to guide percutaneous tricuspid repair.JACC Cardiovasc Interv. 2018; 11: 2540-2542Crossref PubMed Scopus (6) Google Scholar Traditional ICE catheters used for structural heart procedures use phased array transducers and have several limitations, including poor far field visualization, instability of the ICE catheter in the right atrium or ventricle, and inability to manipulate the catheter in all directions.3Hahn R.T. Nabauer M. Zuber M. et al.Intraprocedural imaging of transcatheter tricuspid valve interventions.JACC Cardiovasc Imaging. 2019; 12: 532-553Crossref PubMed Scopus (40) Google Scholar The placement of a pediatric TEE probe into the right atrium overcomes some of these issues but is limited by the large bore venous access needed and possible sterility issues if the sterile probe cover were to become disrupted. A potential solution has been the development of 3-dimensional ICE catheters (which has improved sector angle range, biplane, and 3-dimensional functionality); however, currently, these are not widely available for clinical use. To overcome some of these limitations of the ICE catheter, we placed an ICE catheter (ViewFlex, St. Jude Medical) inside a 9F steerable sheath (FlexCath, Medtronic; Figure 1). This combination improves catheter stability when imaging near-field tricuspid structures. With this configuration, the operator has increased stability of the ICE catheter and added rotation to view the TV apparatus and leaflet grasping. The outer catheter allows for the inner ICE catheter to independently rotate around its central axis to image in multiple planes as opposed to making wide circular motions with ICE while not using a steerable catheter. In our experience, the operator is also able to obtain more acute bends of the catheter in most cases. We have performed 31 TV TEER since 2018, with 18 procedures performed using this technique in patients with suboptimal TEE windows. Tricuspid valve visualization and successful TEER were accomplished in all cases (18 of 18 cases). Compared with the procedure times in cases using only TEE, cases requiring ICE had longer procedure times (159.4 min vs 220.0 min; P = .006) and longer fluoroscopy times (42.5 min vs 99.1 min; P = .0005). Between cases using traditional TEE and those using ICE, there was no significant difference in the number of clips placed (1.7 vs 1.5; P = .57), single leaflet detachment (2 vs 0, P = .17), or the median grade of TR reduction (2.0 vs 2.0; P = .14; Figure 1). Intraprocedural imaging is paramount to the effectiveness of TEER, with poor quality or inadequate visualization leading to less effective treatment and potential morbidity for patients. The use of ICE lengthens procedural and fluoroscopy time because these cases are mired by difficulty with visualization of leaflet grasping by TEE. As a result, with the addition of ICE, there is increased complexity to confirm device position and leaflet insertion when applying both imaging modalities together in addition to the procedural aspect of getting ICE into position, generally leading to increased procedural times. Despite increased procedure times, our limited cohort with baseline suboptimal imaging by TEE alone benefited from the enhanced visualization by ICE inside a steerable catheter for successful TEER without complications associated with the ICE catheter. In patients who are eligible for TV TEER but have limited visualization of TV leaflets by TEE, multimodality imaging with the addition of an ICE catheter placed inside a steerable catheter is a safe and useful adjunct to TV TEER. Dr Greenbaum is a proctor for Edwards Lifesciences and Medtronic. He has an equity interest in Transmural Systems. His employer has research contracts for the clinical investigation of transcatheter aortic, mitral, and tricuspid devices from Edwards Lifesciences, Abbott Vascular, Medtronic, and Boston Scientific. Dr Babaliaros is a consultant for Edwards Lifesciences and Abbott Vascular, and his employer has research contracts for the clinical investigation of transcatheter aortic, mitral, and tricuspid devices from Edwards Lifesciences, Abbott Vascular, Medtronic, and Boston Scientific. He has an equity interest in Transmural Systems. Drs Gleason, Inci, Ram, Xie, Shekiladze, Binongo, and Lisko and author Rainer reported no financial interests. This research was supported by Emory Structural Heart and Valve program intramural funds and by National Institutes of Health (grant number Z01-HL006040 ).

Introduction: The purpose of this study was to investigate the hemodynamic impact of LAMPOON (Laceration of the Anterior Mitral leaflet to Prevent Outflow ObstructioN) in transcatheter mitral valve replacement (TMVR) using patient-specific in silico modeling. Methods: Eight subjects from the LAMPOON investigational device exemption trial were included. All subjects were at prohibitive risk of outflow tract obstruction from TMVR based on computed tomography (CT), and underwent successful LAMPOON immediately followed by TMVR. A validated computational fluid dynamics (CFD) model was used to compare simulated hemodynamics and 3D flow patterns between two modeled conditions: 1) TMVR with LAMPOON and 2) TMVR without LAMPOON. Using the post-procedure CT scans, anatomical models of TMVR with LAMPOON were created for each subject. The open transcatheter valve cells were then virtually closed to model TMVR without LAMPOON for each subject. Finally, CFD was performed for each condition to simulate the systolic flow fields. Results: As compared to TMVR without LAMPOON, TMVR with LAMPOON resulted in lower peak velocity, lower peak LVOT gradient, and higher peak LVOT effective orifice area by 13 ± 6% (p=0.004), 28 ± 14% (p=0.008), and 15 ± 8% (p=0.002), respectively. LAMPOON provided flow communication through exposed cells of the transcatheter valve, thereby decreasing the flow constriction and reducing flow stasis in the vicinity of the neo-LVOT (Figure). The hemodynamic benefit of LAMPOON was observed to be greater in subjects with a smaller neo-LVOT area measured post-implant (p<0.001). Conclusions: In silico modeling allowed for a quantitative patient-specific comparison of TMVR with and without LAMPOON, which is impossible to study clinically. The LAMPOON procedure improved simulated hemodynamics in all subjects, with a greater hemodynamic impact observed in subjects with a smaller post-implant neo-LVOT area.

Coronary obstruction is a rare (<1%) complication of transcatheter aortic valve replacement (TAVR) in native aortic valves that portends a poor prognosis. There are limited CT criteria to assess coronary obstruction risk in patients with native aortic stenosis. This is an international, multi-

Left ventricular outflow tract (LVOT) obstruction is a major complication of transcatheter mitral valve replacement (TMVR) and anterior mitral leaflet (AML) laceration has been shown to reduce the risk of this obstruction. Understanding neo-LVOT geometry is critical for determining risk of LVOT

Coronary obstruction is a rare (<1%) complication of transcatheter aortic valve replacement (TAVR) in native aortic valves that portends a poor prognosis. There are limited computed tomography (CT) criteria to assess coronary obstruction risk in patients with native aortic stenosis. There are no

LAMPOON (intentional laceration of the anterior mitral leaflet to prevent left ventricular outflow tract [LVOT] obstruction) has been shown to reduce the risk of LVOT obstruction. With experience, a simplified antegrade modification of this technique was developed. This is a single-center,

Cardiovascular magnetic resonance (CMR) presents a number of unique opportunities to guide transcatheter cardiovascular interventions. Advances in real-time pulse sequences and user interfaces now allow catheter navigation with temporal resolution approaching that of x-ray fluoroscopy and simultaneous soft tissue visualization similar to echocardiography but unlimited by acoustic windows, and all without ionizing radiation or nephrotoxic contrast. In this chapter we will review the hardware and software components required to build an interventional CMR suite, consider the catheter and device engineering challenges in the CMR environment, and explore current and future clinical applications for this exciting technology.

Transcatheter mitral valve replacement may cause fatal left ventricular outflow tract (LVOT) obstruction due to septal displacement and systolic anterior motion (SAM) of the anterior mitral leaflet. The LAMPOON technique has been used successfully in patients to prevent LVOT obstruction after S3

Left ventricular outflow tract (LVOT) obstruction (LVOTO) is a potentially lethal complication that may arise in transcatheter mitral valve replacement (TMVR). Currently, a 2-dimensional (2-D) Neo-LVOT cross-sectional area of <189.4 mm2 is thought to increase the risk of LVOTO post-implantation.