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OBJECTIVE: The mechanism of left ventricular outflow tract obstruction (LVOTO) is complex in hypertrophic cardiomyopathy (HCM). We aimed to evaluate the impact of mitral valve geometry on LVOTO by echocardiography. MATERIALS AND METHODS: The study population comprised 177 consecutive patients with HCM. Morphological findings of left ventricular hypertrophy and LVOTO-related abnormalities were assessed by comprehensive transthoracic echocardiography. Aortomitral angle, mitral leaflet length, and coaptation height were measured and analyzed at rest. Multivariable stepwise forward logistic regression analysis was performed to identify geometric predictors of LVOTO. RESULTS: One hundred thirty-seven patients had an LVOT gradient ≥30 mm Hg. Multivariable logistic regression showed that aortomitral angle (odds ratio [OR], 0.89; 95% CI, 0.83-0.95, P < .001), coaptation height (OR, 1.96; 95% CI, 1.41-2.72, P < .001), and accessory mitral valve chordae tendineae (OR, 13.1; 95% CI, 4.32-39.95; P < .001) were independently associated with LVOTO. Receiver operating characteristic analysis showed that the area under the curve of mitral coaptation height was higher (area under the curve = 0.815) than the other 2 indicators (P < .05). CONCLUSION: Mitral coaptation height, aortomitral angle, and accessory mitral valve chordae tendineae were important predictors of SAM and LVOTO in HCM independent of septal hypertrophy.

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Transcatheter heart valve replacements (TVR) are mostly designed in a closed position (c) with leaflets coaptating. However, recent literature suggests fabricating valves in semi-closed (sc) position to minimize pinwheeling. With about 100,000 children in need of a new pulmonary valve each year worldwide, this study evaluates both geometrical approaches in adult as well as pediatric size and condition. Three valves of each geometry were fabricated in adult (30 mm) and pediatric (15 mm) size, using porcine pericardium. To evaluate performance, the mean transvalvular pressure gradient (TPG), effective orifice area (EOA), and regurgitation fraction (RF) were determined in three different annulus geometries (circular, elliptic, and tilted). For both adult-sized valve geometries, the TPG (TPGC = 2.326 ± 0.115 mmHg; TPGSC = 1.848 ± 0.175 mmHg)* and EOA (EOAC = 3.69 ± 0.255 cm2; EOASC = 3.565 ± 0.025 cm2)* showed no significant difference. Yet the RF as well as its fluctuation was significantly higher for valves with the closed geometry (RFC = 12.657 ± 7.669 %; RFSC = 8.72 ± 0.977 %)*. Recordings showed that the increased backflow was caused by pinwheeling due to a surplus of tissue material. Hydrodynamic testing of pediatric TVRs verified the semi-closed geometry being favourable. Despite the RF (RFC = 7.721 ± 0.348 cm2; RFSC = 5.172 ± 0.679 cm2), these valves also showed an improved opening behaviour ((TPGC = 20.929 ± 0.497 cm2; TPGSC = 15.972 ± 1.158 cm2); (EOAC = 0.629 ± 0.017 cm2; EOASC = 0.731 ± 0.026 cm2)). Both adult and pediatric TVR with semi-closed geometry show better fluiddynamic functionality compared to valves with a closed design due to less pinwheeling. Besides improved short-term functionality, less pinwheeling potentially prevents early valve degeneration and improves durability. *Results are representatively shown for a circular annulus geometry.

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BACKGROUND: The purpose of the study was to determine the association between vena contracta area (VCA) and secondary leaflet tethering among mitral valve prolapse (MVP) patients, and thus to further identify and characterize an MVP with pathological leaflet tethering (MVPt+) phenotype. METHODS: We prospectively evaluated 94 consecutive MVP patients with significant mitral regurgitation (MR) and 21 healthy controls. MVPt+ group was defined as tenting volume index (TVi) > .7 mL/m2 . The three-dimensional (3D) geometry of mitral valve apparatus and VCA was measured with dedicated quantification software. RESULTS: Of the 94 patients with MVP and significant MR, 31 patients showed a TVi > .7 mL/m2 and entered the MVP with leaflet tethering (MVPt+) group. In stepwise multivariate analysis, only prolapse volume index and TVi were independently associated with 3D VCA. 3D VCA, annular area index, and plasma levels of NT-proBNP were independently correlated with the severity of leaflet tethering. ROC curve revealed that a 3D VCA ≥ .55 cm2 is the optimal cutoff point to predict MVPt+ phenotype. CONCLUSIONS: Secondary leaflet tethering is a significant mechanism behind severe degenerative MR, resulting in an MVPt+ phenotype featuring more advanced morphological and hemodynamical characteristics.

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Objective: Hypoplastic left heart syndrome (HLHS) is a congenital disease characterized by an underdevelopment of the anatomical components inside the left heart. Approximately 30% of HLHS newborns will develop tricuspid regurgitation (TR), and it is currently unknown how the valve annulus mechanics and geometry are associated with regurgitation. Thus, we present an engineering mechanics-based analysis approach to quantify the mechanics and geometry of the HLHS-afflicted tricuspid valve (TV), using 4-dimensional echocardiograms. Methods: Infants born with hypoplastic left heart syndrome (n=8) and healthy newborns (n=4) had their tricuspid valves imaged, and the data was imported to the 3D Slicer. The annular curves were defined at five points in the cardiac cycle. The geometry and deformation (strain) of the TV annulus were calculated to elucidate the mechanics of this critical structure, and compare them between HLHS and normal neonates. Results: For the annular geometry, HLHS-afflicted newborns had significantly larger annular circumferences (20-30%) and anterior-posterior diameters (35-45%) than the healthy patients. From a biomechanics perspective, the HLHS patients had significantly smaller strains in the anterior segments (-0.1±2.6%) during end diastolic and end isovolumetric relaxation (1.7±3.0%) compared to the healthy counterparts (-13.3±2.9% and 6.8±0.9%, respectively). Conclusions: The image-based analysis in this study may provide novel insights into the geometric and mechanistic differences in the TV annulus between healthy and HLHS newborns. Future longitudinal studies of the biomechanics of TV annulus and other subvalvular structures may inform our understanding of the initiation and development of TR and the design of optimal repairs in this challenging population.

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Background: Grade 2+ residual mitral regurgitation (MR 2+) is associated with the recurrence of MR and a lower survival rate in interventional mitral valve (MV) edge-to-edge (EE) repair. We sought to determine the MV anatomic factors affecting residual MR 2+ during interventional EE repair with the ValveClamp system in patients with degenerative MR (DMR). Methods: In this multicenter study, 62 patients with significant (grade 3+ to 4+) DMR underwent ValveClamp implantation across eight centers from July 2018 to December 2019. Patient clinical, anatomical, and procedural characteristics were prospectively collected and retrospectively analyzed. Results: A single clamp was implanted in 59 patients, and two clamps were implanted in three patients. Residual MR 2+ was found in 14 patients (22.6%) immediately after the ValveClamp procedure. Patients with residual MR 2+ showed significantly larger preoperative tenting sizes and annular dimensions than the residual MR ≤1+ group. Multivariate analysis identified tenting volume as the major determinant of residual MR 2+ after ValveClamp procedures (odds ratio, 1.410 per 0.1-mL/m2 increase; 95% confidence interval, 1.167-1.705; P < 0.001). Receiver operating characteristic curves identified a tenting volume index ≥0.82 mL/m2 as the optimal cutoff point to predict residual MR 2+ (area under curve, 0.84). Patients with a tenting volume index ≥0.82 mL/m2 were more likely to develop recurrent 3+ MR or undergo MV surgery during short-term follow-up (P < 0.001). Conclusions: Preoperative assessment of the tenting volume index will help to predict intraoperative residual MR 2+ in patients with DMR receiving EE-based interventional repair. Improvements in the interventional strategy are warranted for sustained MR reduction in patients with DMR with unfavorable anatomy.

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OBJECTIVES: We sought to assess the acute intraprocedural effects of the ValveClamp system in DMR patients on the mitral valve (MV) three-dimensional (3D) geometry and the association of these effects with mitral regurgitation (MR) reduction. BACKGROUND: Few data are available about the specific impact of transcatheter edge-to-edge repair in patients with degenerative mitral regurgitation (DMR). METHODS: Thirty-five symptomatic patients (age 74.26 ± 6.61 years) with Grade 3 to 4+ degenerative MR underwent 3D transoesophageal echocardiography (TEE) during ValveClamp implantation. Volumetric data sets were retrospectively analyzed using mitral valve quantitative 3D modeling software. RESULTS: Mitral valve annular anterior-posterior (AP) diameter decreased from 33.24 ± 4.03 to 31.12 ± 3.66 mm (p < .001), and prolapse height from 4.78 ± 2.19 to 2.32 ± 1.92 mm (p < .001), and total exposed leaflet area from 1,110.29 ± 224.21 mm2 to 1,013.44 ± 228.71 mm (p = .004). Accordingly, we observed a significant reduction of MR severity after ValveClamp implantation. Multivariable analysis revealed postprocedural MR reduction was associated with shortening in anterior-posterior diameter (coefficient 0.427, p = .008) and reduction in prolapse height (coefficient 0.369, p = .021). CONCLUSIONS: ValveClamp implantation exerts an acute effect on the 3D MV geometry. Postprocedural reduction in AP diameter and reduction in prolapse height correlates with MR downgrading in patients with degenerative MR.

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The aortic valve is the functional unit of cusp and root. Various geometrical and functional analyses for the aortic valve unit have been executed to understand normal valve configuration and improve aortic valve repair. Different concepts and procedures have then been proposed for reparative approach, and aortic valve repair is still not standardized like mitral valve repair. It has become apparent, however, that interpretation of the geometry of the aortic cusp and root and its appropriate application to operative strategy lead to creating a functioning aortic valve. Herein, the aortic valve geometry and its clinical implications are reviewed to provide information for the selection of appropriate operative strategies.

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BACKGROUND: The advent of three-dimensional echocardiography (3DE) enables detailed evaluation of the tricuspid valve (TV) apparatus; nonetheless, the clinical value of preoperative 3DE is unknown in patients undergoing tricuspid annuloplasty (TA). The aim of this study was to evaluate the prognostic value of TV geometric parameters and leaflet coaptation status evaluated by 3DE in patients undergoing TA. METHODS: A total of 122 patients who underwent TA during left-sided heart valve surgery were prospectively evaluated. Detailed 3DE was performed before surgery. Adverse outcome was defined as the occurrence of heart failure requiring hospital admission or all-cause mortality following TA. RESULTS: A total of 33 adverse events (17 heart failures and 16 deaths) occurred during a median follow-up of 36 months. Tethering volume (hazard ratio = 1.32; 95% CI = 1.05-1.66; P = .01) and ratio of total leaflet length to closure length (hazard ratio = 1.07; 95% CI = 1.03-1.12; P < .01) were associated with adverse events after adjustment for age, sex, and tricuspid regurgitation vena contracta width. Receiver-operator characteristic curve analysis revealed that tethering volume (area under curve = 0.73) and ratio of total leaflet length to closure length (area under curve = 0.75) were most associated with adverse events at 1-year follow-up. The presence of either a large tethering volume or a low ratio of total leaflet length to closure length was predictive of an adverse outcome 1 year following TA. CONCLUSIONS: Our study suggests that 3DE-derived TV tethering volume and ratio of total leaflet length to closure length are important preoperative measures associated with adverse events in patients undergoing TA.

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OBJECTIVES: The goal of this study was to quantify the mitral valve (MV) annulus, the MV shape and the anatomical MV orifice area throughout the cardiac cycle using 4-dimensional MV analysis software in patients with primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR) in comparison to a healthy control group. METHODS: Three-dimensional transoesophageal echocardiograms of the MV were acquired for 29 patients with PMR, for 28 patients with SMR and for 18 healthy control subjects. The MV was quantified with regards to anterior-posterior and lateromedial diameter, annular area and circumference, intertrigonal (IT) distance, annular sphericity index, annular height to commissural width ration, and anatomical MV orifice area throughout the cardiac cycle using 3-dimensional transoesophageal echocardiography-based 4-dimensional MV advanced analysis software. RESULTS: Normal annulus dynamics display a systolic enlargement followed by an early-diastolic plateau phase and a late-diastolic contraction. The IT distance showed a linear association with the anterior-posterior diameter (= 1.11 × IT distance) and lateromedial diameter (= 1.44 × IT distance) in the control subjects. Mitral regurgitation is associated with a less dynamic, planar and dilated annulus with small variations between PMR and SMR. The IT distance was less affected by mitral regurgitation compared to the control subjects. CONCLUSIONS: The novel 4-dimensional MV analysis allows new insights into the dynamic MV geometry in patients with PMR and SMR compared to the control subjects. The IT distance may be used to predict annuloplasty ring sizing.

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BACKGROUND: The aim of this study was to quantify the acute dynamic changes of mitral valve (MV) geometry throughout the cardiac cycle-during percutaneous MV repair with the MitraClip system by 3-dimensional transesophageal echocardiography (3D TEE). METHODS: The MV was imaged throughout the cardiac cycle (CC) before and after the MitraClip procedure using 3D TEE in 28 patients (mean age, 77 ± 8 years) with functional mitral regurgitation (FMR). Dynamic changes in the MV annulus geometry and anatomical MV orifice area (AMVOA) were quantified using a novel semi-automated software. RESULTS: Percutaneous MV repair decreased anterior-posterior diameter by up to 9% (at 50% of CC; from 34.5 to 31.9 mm; p < 0.001) throughout the CC and increased the diastolic lateral-medial diameter by up to 7% (at 60% of the CC; from 39.7 to 42.3 mm; p < 0.001), whereas the annular circumference and area were not significantly affected. Annulus sphericity index was reduced up to 13% (at 50% of the CC; from 0.89 to 0.78, p < 0.001). The AMVOA also decreased during systole, the maximum decrease being from 0.6 to 0.2 mm2 (at 0% of CC; p = 0.007), and during diastole the maximum decrease being from 4.6 to 1.6 cm2 (at 50% of CC; p < 0.001). CONCLUSIONS: Percutaneous MV repair reduces the MR by an improved coaptation of MV leaflets joint with a simultaneous indirect reduction of anterior-posterior diameter. Further, the MitraClip procedure leads to a reduction of AMVOA of more than 60% during diastole.

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Ischemic mitral regurgitation (IMR) is a form of mitral insufficiency that is characterized by papillary muscle (PM) displacement, leaflet tethering, reduced closing forces, and different degree of annular dilatation. Treatment of this condition includes mitral valve replacement or mitral valve repair with restrictive annuloplasty. Recent evidences in mitral valve repair showed that addressing only the annulus and neglecting the subvalvular apparatus provides a suboptimal operation with poor long-term results. However, the complexity of the geometrical aberrances occurring in IMR demands for more accurate analysis also involving the biomechanics underlying the failing mitral valve and subvalvular apparatus. Finite element analysis (FEA) is a powerful tool in this context and we developed a biomechanical model of mitral valve and subvalvular unit using 3D geometry of the leaflets, annulus, chordae and PM. After the application of structural properties of materials to these elements and simulation of systemic pressure loading, FEA could be used to directly determine biomechanical changes and geometry variations. We believe this approach can provide valuable information to better address the surgical treatment of IMR and answer some of the questions still pending in IMR management.

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BACKGROUND/OBJECTIVES: The acute and long-term effects of interventional edge-to-edge repair on the mitral valve (MV) geometry are unclear. We sought to assess MV-annular geometry and the association of changes in MV-diameters with functional response one year after MitraClip implantation. METHODS: Consecutive patients (n=84; age 81.2±8.3years, logistic EuroSCORE 21.7±17.9%) with symptomatic moderate-to-severe mitral regurgitation (MR) underwent MitraClip-procedure. MV-annular geometry was assessed with 3D TOE before, immediately and one year after clip implantation. RESULTS: 96.7% of secondary mitral regurgitation (SMR) patients presented with moderate-to-severe MR, 3.3% with severe SMR, respectively. 66.7% of primary MR (PMR) patients had moderate-to-severe MR, and 33.3% severe PMR respectively. When analyzing immediate effects of MitraClipC on mitral geometry, only patients with SMR (n=60, 71.4%) experienced significant reductions of the diastolic MV anterior-posterior diameters (AP: 3.9±0.5cm, 3.5±0.7cm; p<0.001), and annulus-areas (2D: 12.9±3.8cm2, 12.6±3.7cm2; p<0.001; 3D: 13.4±3.8, 13.1±3.2cm2; p<0.001). All measures on MV annular geometry were not significantly altered in patients with PMR (p>0.05). After one year of follow-up, MV annular parameters remained significantly reduced in SMR patients (p<0.05) and remained unchanged in subjects with PMR (p>0.05). Only SMR patients experienced significant increase in 6min walking distances (p=0.004), decrease in pulmonary pressures (p=0.007) and functional NYHA-class (p<0.001); in patients with PMR only NYHA class improved after one year (p<0.001). CONCLUSION: Edge-to-edge repair with the MitraClip-system impacts on MV-geometry in patients with SMR with stable results after 12months. Reduction of MV-annular dimensions was associated with higher rates of persisting MR reduction and better functional status in patients with SMR.

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To conduct a patient-specific computational modeling of the aortic valve, 3-D aortic valve anatomic geometries of an individual patient need to be reconstructed from clinical 3-D cardiac images. Currently, most of computational studies involve manual heart valve geometry reconstruction and manual finite element (FE) model generation, which is both time-consuming and prone to human errors. A seamless computational modeling framework, which can automate this process based on machine learning algorithms, is desirable, as it can not only eliminate human errors and ensure the consistency of the modeling results but also allow fast feedback to clinicians and permits a future population-based probabilistic analysis of large patient cohorts. In this study, we developed a novel computational modeling method to automatically reconstruct the 3-D geometries of the aortic valve from computed tomographic images. The reconstructed valve geometries have built-in mesh correspondence, which bridges harmonically for the consequent FE modeling. The proposed method was evaluated by comparing the reconstructed geometries from 10 patients with those manually created by human experts, and a mean discrepancy of 0.69 mm was obtained. Based on these reconstructed geometries, FE models of valve leaflets were developed, and aortic valve closure from end systole to middiastole was simulated for 7 patients and validated by comparing the deformed geometries with those manually created by human experts, and a mean discrepancy of 1.57 mm was obtained. The proposed method offers great potential to streamline the computational modeling process and enables the development of a preoperative planning system for aortic valve disease diagnosis and treatment.

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OBJECTIVE: To assess the impact of mitral geometry, left ventricular (LV) remodelling and global LV afterload on mitral regurgitation (MR) after trans-catheter aortic valve implantation (TAVI). METHODS: In this study, 60 patients who underwent TAVI were evaluated by 3D echocardiography at baseline, 1 month and 6 months after procedure. The proportional change in MR following TAVI was determined by examining the percentage change in vena contracta (VC) at 6 months. Patients having a significant reduction of at least 30% in VC were defined as good responders (GR) and the remaining patients were defined as poor responders (PR). RESULTS: After 6 months of TAVI, 27 (45%) patients were GR and 33 (55%) were PR. There was a significant decrease in 3DE-derived mitral annular diameter and area (P = 0.001), mitral valve tenting area (TA) (P = 0.05), and mitral papillary muscle dyssynchrony index (DSI) (P = 0.05) in the GR group. 3DE-derived LVESV (P = 0.016), LV mass (P = 0.001) and LV DSI, (P = 0.001) were also improved 6 months after TAVI. In addition, valvulo-arterial impedance (ZVA) was significantly higher at baseline in patients with PR (P = 0.028). 3DE-derived mitral annular area (ß: 0.47, P = 0.04), mitral papillary DSI (ß: -0.65, P = 0.012) and ZVA (ß: 0.45, P = 0.028) were the strongest independent parameters that could predict the reduction of functional MR after TAVI. CONCLUSION: GR patients demonstrate more regression in mitral annulus area and diameter after significant decrease in high LVEDP and trans-aortic gradients with TAVI. PR patients appear to have increased baseline ZVA, mitral valve tenting and restriction in mitral valve coaptation. These factors are important for predicting the impact of TAVI on pre-existing MR.

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PURPOSE: Mitral valve reconstruction is a widespread surgical method to repair incompetent mitral valves, which usually includes implantation of a ring prosthesis. To date, intraoperative analysis of the mitral valve is merely based on visual assessment using simple surgical tools, which might not allow for accurate assessment of the complex anatomy. METHODS: We propose a novel intraoperative computer-based assistance system, which combines passive optical tracking technology with tailored measurement strategies applicable during different phases of the intraoperative workflow. Based on the assessment of the valvular apparatus by customized tracked instruments, the system (1) generates an enhanced three-dimensional visualization, which (2) incorporates accurate quantifications and (3) provides assistance, e.g., in terms of virtual prosthesis selection. RESULTS: Phantom experiments in a realistic environment revealed a high system accuracy (mean precision [Formula: see text] mm and mean trueness [Formula: see text] mm) and a low user error (mean precision [Formula: see text] mm and mean trueness [Formula: see text] mm). The assistance system was successfully applied five times during open and minimally invasive reconstructive surgery in patients having mitral valve insufficiency. The measurement steps integrate well into the traditional workflow, enhancing the surgeon's three-dimensional perception and generating a suggestion for an appropriate prosthesis. CONCLUSION: The proposed assistance system provides a novel, accurate, and reproducible method for assessing the valvular geometry intraoperatively.

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AIMS: Percutaneous treatment of mitral regurgitation (MR) has been shown to reduce MR severity and improve functional outcomes. Surgical treatment of MR usually includes mitral annulus reduction. The influence of the MitraClip on annulus geometry is not clear. We wanted to investigate whether the procedure itself reduces annulus diameter and if there may be differences between secondary or functional (SMR) and primary (PMR) MR. METHODS AND RESULTS: We retrospectively assessed 3D echocardiography (3D-TEE) data of 55 patients acquired during the procedure shortly before and after clip placement for changes in annulus diameter and area. Measurements were done with QLAB software. Patients were categorized as having either SMR (n = 41) or PMR (n = 14). In SMR, we were able to demonstrate a significant reduction in annulus area (meanΔ 1.30 ± 1.44 cm2; P < 0.001), anterior-posterior (AP)-diameter (meanΔ 0.28 ± 0.32 cm; P < 0.001), tenting area (meanΔ 0.39 ± 0.49 cm2; P < 0.001). No significant change could be found for latero-medial (LM)-diameter. In contrast, we could not demonstrate significant changes in any of the parameters described above in patients with PMR. CONCLUSION: Percutaneous treatment with the MitraClip device can produce immediate reductions in mitral annulus size in SMR, probably supporting procedural success. It also reduces tenting, which may have prognostic implications. In contrast, these effects on mitral geometry cannot be demonstrated in PMR. Knowledge of this difference between SMR and PMR may be important to improve procedural strategies.

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