Mitral Valve Geometry Research Articles

Fluid-Structure Interaction Analysis of Ruptured Mitral Chordae Tendineae.

The chordal structure is a part of mitral valve geometry that has been commonly neglected or simplified in computational modeling due to its complexity. However, these simplifications cannot be used when investigating the roles of individual chordae tendineae in mitral valve closure. For the first time, advancements in imaging, computational techniques, and hardware technology make it possible to create models of the mitral valve without simplifications to its complex geometry, and to quickly run validated computer simulations that more realistically capture its function. Such simulations can then be used for a detailed analysis of chordae-related diseases. In this work, a comprehensive model of a subject-specific mitral valve with detailed chordal structure is used to analyze the distinct role played by individual chordae in closure of the mitral valve leaflets. Mitral closure was simulated for 51 possible chordal rupture points. Resultant regurgitant orifice area and strain change in the chordae at the papillary muscle tips were then calculated to examine the role of each ruptured chorda in the mitral valve closure. For certain subclassifications of chordae, regurgitant orifice area was found to trend positively with ruptured chordal diameter, and strain changes correlated negatively with regurgitant orifice area. Further advancements in clinical imaging modalities, coupled with the next generation of computational techniques will enable more physiologically realistic simulations.

Predictors and Prognostic Impact of Progressive Ischemic Mitral Regurgitation in Patients With Advanced Ischemic Cardiomyopathy: A Multimodality Study.

Ischemic mitral regurgitation (IMR) is associated with poor outcomes. It is unknown what factors contribute to progression of IMR and how progressive IMR affects outcomes. We sought to determine imaging predictors of IMR progression and to determine if progressive IMR is an independent predictor of survival in patients with advanced ischemic cardiomyopathy. Consecutive advanced ischemic cardiomyopathy patients who underwent cardiac magnetic resonance and echocardiograms at baseline with echocardiographic follow-up were studied. Cardiac magnetic resonance was used to assess left ventricular volumes, infarct size, and mitral valve geometry. The effective regurgitant orifice area (EROA) was calculated from the proximal isovelocity surface area by echocardiography. Repeated measures mixed effects and Cox proportional hazards regression models were built to identify predictors of IMR progression and survival. We evaluated 336 patients (age, 62±11 years) over a median follow-up time of 54 months: 154 patients were subsequently revascularized, and 182 patients were medically treated. Ninety-eight patients (29%) demonstrated an increase in EROA values of ≥0.1 cm(2). There were 87 adverse events (death or transplant). On multivariable analysis, infarct size (P<0.001), progression in IMR (P=0.008), age (P=0.003), and baseline EROA (P=0.010) were independently associated with adverse events. Independent predictors of IMR progression were as follows: baseline EROA (P<0.001), left ventricular end-systolic volume index (P=0.014), and total scar (P=0.036). IMR frequently increases in severity, and progression is independently associated with adverse left ventricular remodeling and infarct size, as assessed by cardiac magnetic resonance. Furthermore, IMR progression is a powerful independent predictor of adverse events, even after controlling for the severity of IMR at baseline.

A biomimetic bi-leaflet mitral prosthesis with enhanced physiological left ventricular swirl restorative capability

Mechanical heart valve prostheses are often implanted in young patients due to their durability and long-term reliability. However, existing designs are known to induce elevated levels of blood damage and blood platelet activation. As a result, there is a need for patients to undergo chronic anti-coagulation treatment to prevent thrombosis, often resulting in bleeding complications. Furthermore, recent studies have suggested that the implantation of a mechanical prosthetic valve at the mitral position results in a significant alteration of the left ventricular flow field which may contribute to flow turbulence. This study proposes a bi-leaflet mechanical heart valve design (Bio-MHV) that mimics the geometry of a human mitral valve, with the aim of reducing turbulence levels in the left ventricle by replicating physiological flow patterns. An in vitro three-dimensional particle velocimetry imaging experiment was carried out to compare the hemodynamic performance of the Bio-MHV with that of the clinically established ATS valve. The Bio-MHV was found to replicate physiological left ventricular flow patterns and produced lower turbulence levels.

Multislice computed tomography-guided surgical repair of acquired posterior left ventricular aneurysms: demonstration of mitral valve and left ventricular reverse remodelling.

Involvement of the mitral valve (MV) apparatus represents a challenge in surgical ventricular repair (SVR) of posterior left ventricular (LV) aneurysms. This study sought to investigate whether multislice computed tomography (MSCT) assessment can be used to optimize the surgical procedure for posterior LV aneurysms. Thirty patients (m : w = 24 : 6, age 38-78, median 66 years; mean New York Heart Association class 2.98) with posterior LV aneurysm were operated upon. MSCT was performed in 24 patients before and after surgery. End-diastolic and end-systolic volumes of LV and aneurysm were indexed to body surface area (LVEDVI/LVESVI, AEDVI/AESVI). The MV apparatus was characterized by coaptation distance (CD), tenting area (TA), MV closure angle (MVCA), MV annulus area (MVAA) and interpapillary muscle distance (IMD). Thirty-day mortality was 10% and 5-year survival rate was 83%. After surgery, LVEDVI decreased from 151.2 ± 84.1 to 85.7 ± 28.3 ml/m(2) (P = 0.001) and LVESVI from 110.6 ± 88.8 to 50.2 ± 22.9 ml/m(2) (P = 0.001). LV ejection fraction increased from 31.5 ± 15.1 to 43.4 ± 9.9% (P = 0.001). Preoperative MSCT showed significantly higher values of MVAA, CD and TA in patients who needed MV repair or replacement. Postoperative reduction of mitral regurgitation in patients without MV surgery corresponded with significant reduction in intercommissural diameter, anteroposterior diameter, MVAA, TA, CD, MVCA and IMD. MSCT represents an excellent diagnostic tool for the assessment of MV and LV geometry. MSCT-guided SVR of submitral LV aneurysms leads to excellent mid-term results. On the basis of the MSCT assessment, we propose an algorithm for surgical planning in posterior LV aneurysms.

Personalized mitral valve closure computation and uncertainty analysis from 3D echocardiography.

Intervention planning is essential for successful Mitral Valve (MV) repair procedures. Finite-element models (FEM) of the MV could be used to achieve this goal, but the translation to the clinical domain is challenging. Many input parameters for the FEM models, such as tissue properties, are not known. In addition, only simplified MV geometry models can be extracted from non-invasive modalities such as echocardiography imaging, lacking major anatomical details such as the complex chordae topology. A traditional approach for FEM computation is to use a simplified model (also known as parachute model) of the chordae topology, which connects the papillary muscle tips to the free-edges and select basal points. Building on the existing parachute model a new and comprehensive MV model was developed that utilizes a novel chordae representation capable of approximating regional connectivity. In addition, a fully automated personalization approach was developed for the chordae rest length, removing the need for tedious manual parameter selection. Based on the MV model extracted during mid-diastole (open MV) the MV geometric configuration at peak systole (closed MV) was computed according to the FEM model. In this work the focus was placed on validating MV closure computation. The method is evaluated on ten in vitro ovine cases, where in addition to echocardiography imaging, high-resolution μCT imaging is available for accurate validation.

Acute effect of MitraClip implantation on mitral valve geometry in patients with functional mitral regurgitation: insights from three-dimensional transoesophageal echocardiography.

Our aim was to evaluate the acute effects of transcatheter edge-to-edge mitral valve repair using the MitraClip device on mitral valve geometry in patients with functional mitral regurgitation (FMR). Forty-two patients (age 73 years [IQ range 66.1-78.0], 55% men, 62% ischaemic FMR) with moderate-to-severe and severe FMR treated with the MitraClip were included. Three-dimensional transoesophageal echocardiography was performed prior to and immediately after MitraClip implantation. Acute changes of mitral annular and leaflet geometry were assessed with dedicated mitral modelling software. FMR less than moderate grade was achieved in 36 (86%) patients. After MitraClip implantation, the mitral annulus became more elliptical (ellipticity from 122±17% to 129±18%; p=0.04) with a non-significant reduction in anteroposterior diameter (33±6 to 32±5 mm, p=0.08). The coaptation area increased from 350 mm2 (IQ range 289-493 mm2) to 434 mm2 (IQ range 328-523 mm2, p=0.008). In particular, a larger part of the anterior mitral leaflet was included in the coaptation, leaving a smaller exposed anterior leaflet length of the A2 segment (from 27±6 mm to 25±5 mm, p<0.05) while the exposed length of the posterior leaflet (P2 level) remained unchanged (12±4 mm pre- vs. 13±4 mm post-repair, p=0.15). There was no change in total leaflet area (1,811±582 mm2 pre- vs. 1,870±506 mm2 post-repair, p=0.18). Annular height to intercommissural width ratio and tenting volume remained unchanged, suggesting no increase in leaflet stress. The MitraClip device affects MV geometry in FMR patients by increasing mitral annular ellipticity and coaptation area.

High-resolution subject-specific mitral valve imaging and modeling: experimental and computational methods.

The diversity of mitral valve (MV) geometries and multitude of surgical options for correction of MV diseases necessitates the use of computational modeling. Numerical simulations of the MV would allow surgeons and engineers to evaluate repairs, devices, procedures, and concepts before performing them and before moving on to more costly testing modalities. Constructing, tuning, and validating these models rely upon extensive in vitro characterization of valve structure, function, and response to change due to diseases. Micro-computed tomography ([Formula: see text]CT) allows for unmatched spatial resolution for soft tissue imaging. However, it is still technically challenging to obtain an accurate geometry of the diastolic MV. We discuss here the development of a novel technique for treating MV specimens with glutaraldehyde fixative in order to minimize geometric distortions in preparation for [Formula: see text]CT scanning. The technique provides a resulting MV geometry which is significantly more detailed in chordal structure, accurate in leaflet shape, and closer to its physiological diastolic geometry. In this paper, computational fluid-structure interaction (FSI) simulations are used to show the importance of more detailed subject-specific MV geometry with 3D chordal structure to simulate a proper closure validated against [Formula: see text]CT images of the closed valve. Two computational models, before and after use of the aforementioned technique, are used to simulate closure of the MV.

Acute effect of MitraClip implantation on mitral valve geometry in patients with functional mitral regurgitation: insights from three-dimensional transoesophageal echocardiography.

Our aim was to evaluate the acute effects of transcatheter edge-to-edge mitral valve repair using the MitraClip device on mitral valve geometry in patients with functional mitral regurgitation (FMR). Forty-two patients (age 73 years [IQ range 66.1-78.0], 55% men, 62% ischaemic FMR) with moderate-to-severe and severe FMR treated with the MitraClip were included. Three-dimensional transoesophageal echocardiography was performed prior to and immediately after MitraClip implantation. Acute changes of mitral annular and leaflet geometry were assessed with dedicated mitral modelling software. FMR less than moderate grade was achieved in 36 (86%) patients. After MitraClip implantation, the mitral annulus became more elliptical (ellipticity from 122±17% to 129±18%; p=0.04) with a non-significant reduction in anteroposterior diameter (33±6 to 32±5 mm, p=0.08). The coaptation area increased from 350 mm2 (IQ range 289-493 mm2) to 434 mm2 (IQ range 328-523 mm2, p=0.008). In particular, a larger part of the anterior mitral leaflet was included in the coaptation, leaving a smaller exposed anterior leaflet length of the A2 segment (from 27±6 mm to 25±5 mm, p<0.05) while the exposed length of the posterior leaflet (P2 level) remained unchanged (12±4 mm pre- vs. 13±4 mm post-repair, p=0.15). There was no change in total leaflet area (1,811±582 mm2 pre- vs. 1,870±506 mm2 post-repair, p=0.18). Annular height to intercommissural width ratio and tenting volume remained unchanged, suggesting no increase in leaflet stress. The MitraClip device affects MV geometry in FMR patients by increasing mitral annular ellipticity and coaptation area.

Clinical implications of mitral valve geometric alterations in children with dilated cardiomyopathy.

We aimed to elucidate the relationship between severity of secondary mitral regurgitation and mitral valve geometry in children with dilated cardiomyopathy. The medical records of 16 children with dilated cardiomyopathy (median age, 1.2 years; range, 0.4-12.3 years) were reviewed. Mitral valve geometry was evaluated by measuring coaptation depth using echocardiographic apical four-chamber views at the initial presentation. Patients were dichotomised according to the mitral regurgitation severity: patients with moderate or severe secondary mitral regurgitation (n=6) and those with mild secondary mitral regurgitation (n=10). A total of 58 healthy children were considered as normal controls, and a regression equation to predict coaptation depth by body surface area was derived: coaptation depth [mm]=4.37+1.34×ln (body surface area [m2]) (residual standard error, 0.49; adjusted R2, 0.68; p<0.0001). Compared with patients with mild secondary mitral regurgitation, those with moderate or severe secondary mitral regurgitation had significantly larger coaptation depth z-scores (6.4±2.3 versus 1.9±1.4, p<0.005), larger mitral annulus diameter z-scores (3.6±2.6 versus 0.9±1.8, p<0.05), higher left ventricular sphericity index (0.89±0.07 versus 0.79±0.06, p<0.005), and greater left ventricular fraction shortening (0.15±0.05 versus 0.09±0.05, p<0.05). In conclusion, geometric alteration in the mitral valve and the left ventricle is associated with the severity of secondary mitral regurgitation in paediatric dilated cardiomyopathy, which would provide a theoretical background to surgical intervention for secondary mitral regurgitation in paediatric populations.

Abstract 13643: Impact of Aortic Valve Repair and Valve-sparing Procedures on the Mitral Annular Geometry Assessed by 3-dimensional Transesophageal Echocardiography

Background: Annular non-planarity, the "saddle-shape" of the mitral valve (MV) annulus, plays a role in minimizing leaflet stress and preserving valve function. Aortic valve (AV) repair/sparing procedures are increasingly used to treat aortic regurgitation (AR). The impact of these procedures on MV geometry and function is unknown. Methods: 2D and 3D transesophageal echocardiography (TEE) of the MV was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n=10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation; Group 2 (n=10): tricuspid AV undergoing AV repair and AV reimplantation; Group 3 (n=10): isolated AV cusp repair) and in 10 controls (Group 4). MV morphology was assessed by dedicated quantification software (fig. 1). Results: Comorbidities were similar in all groups. Groups 1, 2 and 3 had increased LV end-diastolic volumes compared to group 4 (214±90, 193±56, 180±55 vs. 86± 28ml for groups 1, 2, 3 and 4, respectively; p&lt;0.001); LVEF was similar (59.5 ± 6.2%). The baseline dimensions of the ventriculo-aortic junction and sinuses of Valsalva were larger in groups 1 and 2 vs. groups 3 and 4 (p&lt;0.0001). AV and MV parameters are summarized (table). Pre-operative MV parameters did not differ from those of normal subjects. The annular height and annular height to commissural width ratio (AHCWR) significantly decreased after surgery in groups 1 and 2, as did the tenting area. Significant changes in the coaptation depth and mitro-aortic angle were only found in group 1. Conclusions: AV repair/sparing procedures alter the MV geometry, including the non-planarity of the annulus and the depth of coaptation of the leaflets, especially among patients with a bicuspid AV undergoing AV reimplantation. These alterations could have long-term implications on MV function.

Cardiac computed tomography assessment of the near term impact of percutaneous ventricular restoration therapy (parachute(®) ) on mitral valve geometry.

The aim of current study is to assess the near term impact of percutaneous ventricular restoration therapy (PVR), Parachute(®) on mitral valve (MV) geometry by cardiac computed tomography (CCT). Recent data demonstrates the feasibility of PVR for treatment of post anterior myocardial infarction (MI) heart failure. Little is known, however, about the interaction of the device and left ventricular structures, particularly the MV apparatus. This is a retrospective Core Laboratory analysis of Parachute Trials' CCT data. Patients with paired (before and after Parachute implant) CCT acquisitions were included into analysis. MV geometric parameters were measured. Thirty-three patients were included in the analysis. The mean time of follow-up CCT post procedure was 188 ± 52 days. There were significant reduction in tenting height (A1P1: -1.70 ± 1.89 mm, -17.40 ± 20.20%; A2P2: -1.43 ± 1.89 mm, -12.10 ± 15.00%; A3P3: -1.54 ± 1.58 mm, -15.50 ± 15.20%, P < 0.001), tenting volume (-0.93 ± 0.60 mm3, -22.00 ± 11.40%, P < 0.001), systolic interpapillary muscle distance (-2.22 ± 2.11 mm, -7.51 ± 7.23%, P < 0.001) and diastolic interpapillary muscle distance (-3.14 ± 2.20 mm, -8.46 ± 5.73%, P < 0.001) post PVR. In post anterior MI heart failure patients, PVR has favorable near term impact on MV geometry as assessed by CCT. © 2015 Wiley Periodicals, Inc.

IMPACT OF AORTIC VALVE REPAIR AND VALVE-SPARING PROCEDURES ON THE MITRAL ANNULAR GEOMETRY ASSESSED BY 3-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Background: Annular non-planarity, the saddle-shape of the mitral valve (MV) annulus, plays a role in minimizing leaflet stress and preserving valve function. Aortic valve (AV) repair/sparing procedures are increasingly used to treat aortic regurgitation (AR). The impact of these procedures on MV geometry and function is unknown. Methods: 2D and 3D transesophageal echocardiography (TEE) of the MV was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n=10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation; Group 2 (n=10): tricuspid AV undergoing AV repair and AV reimplantation; Group 3 (n=10): isolated AV cusp repair) and in 10 controls (Group 4). MV morphology was assessed by dedicated quantification software (fig. 1). Results: Comorbidities were similar in all groups. Groups 1, 2 and 3 had increased LV end-diastolic volumes compared to group 4 (214±90, 193±56, 180±55 vs. 86± 28ml for groups 1, 2, 3 and 4, respectively; p<0.001); LVEF was similar (59.5 ± 6.2%). The baseline dimensions of the ventriculo-aortic junction and sinuses of Valsalva were larger in groups 1 and 2 vs. groups 3 and 4 (p<0.0001). AV and MV parameters are summarized (table). Pre-operative MV parameters did not differ from those of normal subjects. The annular height and annular height to commissural width ratio (AHCWR) significantly decreased after surgery in groups 1 and 2, as did the tenting area. Significant changes in the coaptation depth and mitro-aortic angle were only found in group 1. Conclusions: AV repair/sparing procedures alter the MV geometry, including the non-planarity of the annulus and the depth of coaptation of the leaflets, especially among patients with a bicuspid AV undergoing AV reimplantation. These alterations could have long-term implications on MV function.

Transaortic Chordal Cutting: Mitral Valve Repair for Obstructive Hypertrophic Cardiomyopathy With Mild Septal Hypertrophy

BackgroundIn severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) and mild septal hypertrophy, mitral valve (MV) abnormalities may play an important role in MV displacement into the left ventricular (LV) outflow tract. Therefore, isolated myectomy may not relieve outflow obstruction and symptoms, and MV replacement is often the surgical alternative. ObjectivesThis study sought to assess the clinical and hemodynamic results of cutting thickened secondary MV chordae combined with a shallow septal muscular resection in severely symptomatic patients with obstructive HCM and mild septal hypertrophy. MethodsClinical features were compared before surgery and at most recent clinical evaluation in 39 consecutive patients with obstructive HCM. ResultsOver a 23 ± 2 months follow-up, New York Heart Association functional class decreased from 2.9 ± 0.5 pre-operatively to 1.1 ± 1.1 post-operatively (p < 0.001), with no patient in class III at most recent evaluation. The resting outflow gradient decreased from 82 ± 43 mm Hg to 9 ± 5 mm Hg (p < 0.001) and septal thickness decreased from 17 ± 1 mm to 14 ± 2 mm (p < 0.001). No patient had MV prolapse or flail and 1 had residual moderate-to-severe MV regurgitation at most recent evaluation. MV geometry before and after surgery was compared with that of 25 consecutive patients with similar clinical profile and septal thickness that underwent isolated myectomy. After adjustment for differences in pre-operative values between the groups, the post-operative anterior MV leaflet-annulus ratio was 17% greater and tenting area 24% smaller in patients with chordal cutting, indicating that MV apparatus had moved to a more normal posterior position within the LV cavity, preventing MV systolic displacement into the outflow tract and outflow obstruction. ConclusionsThis procedure relieves heart failure symptoms, abolishes LV outflow gradient, and avoids MV replacement in patients with obstructive HCM and mild septal thickness.

TCT-721 Four-Dimensional Analysis Of Mitral Valve Geometry Before And After Percutaneous Edge-to-Edge Mitral Valve Repair

Percutaneous treatment of mitral regurgitation (MR) is an option for patients facing a high operative risk. The influence of percutaneous edge-to-edge mitral valve repair (PMVR) on the mitral valve (MV) geometry is not yet clearly understood. We herein in present a novel four-dimensional

Population-Averaged Geometric Model of Mitral Valve From Patient-Specific Imaging Data1

The mitral valve (MV) is one of the atrioventricular heart valves and regulates the blood flow between the left atrium and ventricle during the cardiac cycle. Its anatomical structure is comprised of anterior and posterior leaflets, chordae tendineae, and papillary muscles. The main function of the MV is to prevent blood flow regurgitation back into the left atrium during systole. Abnormalities in geometry of MV can lead to mitral insufficiency disorder, which requires either valve replacement or surgical repair to restore proper MV coaptation. Annually, over 40,000 patients in the U.S. alone are treated for MV disorders [1]. In the past two decades, the emphasis in MV treatment has been shifting from replacement toward repair due to lower morbidity and mortality of the latter approach [2]. However, the natural anatomical variability of human MV geometry precludes the use of single or simplified geometries for the simulation of surgical repair. One of the ways to address this issue is by using patient-specific diagnosis and modeling [3], or population-averaged geometric models of MV. The existing approaches for characterization and reconstruction of the cardiovascular organ-level geometry include fitting of predefined sets of nonuniform rational B-splines (NURBS) to the imaging data [4], and using spheroidal harmonics representations [5]. Even though it is possible to construct average geometric models this way, the analysis of anatomical shape variations becomes difficult in this setting because of the confounding of dimensional and shape descriptors. At the same time, none of the existing methods allow integration of the high-fidelity in vitro data with lower-resolution in vivo imaging in a consistent manner. In this work, we formulate the framework for building the population-averaged geometric model of MV, which lends to straightforward analysis of dimensional and anatomical variations. In the sections to follow, we discuss the procedure and advantages of this method for the development of robust medical devices and treatment procedures.

Biomechanical evaluation of the pathophysiologic developmental mechanisms of mitral valve prolapse: effect of valvular morphologic alteration.

Mitral valve prolapse (MVP) refers to an excessive billowing of the mitral valve (MV) leaflets across the mitral annular plane into the left atrium during the systolic portion of the cardiac cycle. The underlying mechanisms for the development of MVP and mitral regurgitation in association with MV tissue remodeling are still unclear. We performed computational MV simulations to investigate the pathophysiologic developmental mechanisms of MVP. A parametric MV geometry model was utilized for this study. Posterior leaflet enlargement and posterior chordal elongation models were created by adjusting the geometry of the posterior leaflet and chordae, respectively. Dynamic finite element simulations of MV function were performed over the complete cardiac cycle. Computational simulations demonstrated that enlarging posterior leaflet area increased large stress concentration in the posterior leaflets and chordae, and posterior chordal elongation decreased leaflet coaptation. When MVP was accompanied by both posterior leaflet enlargement and chordal elongation simultaneously, the posterior leaflet was exposed to extremely large prolapse with a substantial lack of leaflet coaptation. These data indicate that MVP development is closely related to tissue alterations of the leaflets and chordae. This biomechanical evaluation strategy can help us better understand the pathophysiologic developmental mechanisms of MVP.

Mitral repair with the sole use of a semi-rigid band in a sub-population of patients with Barlow's disease: a 4-year follow-up with stress echocardiography.

Surgical treatment of Barlow's disease is usually demanding. In a sub-population of Barlow patients with bileaflets prolapse and central regurgitant jet, we performed mitral repair using only a semi-rigid annuloplasty band. Stress echocardiography follow-up was evaluated. Of a total of 350 consecutive patients with mitral prolapse, 69 had anatomical features of Barlow's disease. Of these, 40 with multiple large central jets without chordal rupture were repaired only using an annuloplasty band, and these constituted the study group. An echocardiographic study of the acute change in valvular and ventricular morphology before and after surgery was carried out. Patients were evaluated at discharge and after a mean follow-up of 4.7 ± 3.2 years by stress echocardiography. No death or reoperation occurred. Acute echocardiographic study revealed that mitral annuloplasty led to a significant migration of the leaflets towards the apex of the left ventricle. Coaptation length increased dramatically from 2.7 ± 0.8 to 11.3 ± 2.7 mm and a reduction in annular diameters and leaflet length was observed. The left ventricle was elongated (72.8 ± 6.9 vs 63.2 ± 8.1 mm) and the distance from the papillary muscle tip to the mitral annulus increased (anterior 30 ± 3.9 vs 20.3 ± 4.8 mm, posterior 29.7 ± 4.3 vs 20.8 ± 5.6 mm). At discharge, residual mitral regurgitation was mild in 1 case and trivial in 3. The results were confirmed at stress echocardiography follow-up with normal valve function at peak exercise. In patients with severe mitral regurgitation due to Barlow's disease with multiple central jet and without chordal rupture, mitral annuloplasty is effective in restoring mitral valve function owing to profound changes in mitral valve and left ventricle geometry. At follow-up, stress echocardiography confirms the results and the stability of the repair.

Mitral Valve Geometry Changes in Patients with Aortic Regurgitation

Changes in mitral valve geometry in patients with significant aortic regurgitation (AR) have not been evaluated. The aim of the present study was to assess the prevalence of significant secondary mitral regurgitation (MR; grade ≥ 2) and the geometric characteristics of the mitral valve in patients with moderate and severe AR (grade ≥ 2) undergoing aortic valve and root surgery. One-hundred twenty patients (mean age, 54 ± 15 years; 65% men) with AR grade ≥ 2 undergoing aortic valve and root surgery were retrospectively evaluated. The presence of MR grade ≥ 2 and geometry of the mitral valve were assessed on preoperative transthoracic echocardiography. Left ventricular (LV) dimensions and mitral valve geometry were compared between patients with MR grade ≥ 2 and patients without. MR grade ≥ 2 was present in 28 patients (23%). Patients with MR grade ≥ 2 had higher European System for Cardiac Operative Risk Evaluation II scores and more often used β-blockers and diuretics than their counterparts. Patients with MR grade ≥ 2 had larger tenting areas (mean, 1.59 ± 0.79 vs 1.25 ± 0.41 cm(2); P = .003), larger inter-papillary muscle distances (mean, 28.4 ± 9.5 vs 24.8 ± 5.2 mm; P = .014), larger left atria (mean, 40.9 ± 13.7 vs 32.0 ± 12.2 mL/m(2); P = .002), and lower LV ejection fractions (mean, 47.3 ± 12.2% vs 54.3 ± 9.3%; P = .002) as compared to patients with MR grade < 2. However, there were no differences in indexed LV volumes. On multivariate logistic regression analysis, LV ejection fraction (odds ratio, 0.94; 95% confidence interval, 0.89-0.99; P = .018) and indexed left atrial volume (odds ratio, 1.05; 95% confidence interval, 1.01-1.10; P = .019) remained independently associated with MR grade ≥ 2 after correcting for tenting area and inter-papillary muscle distance. Among patients with AR grade ≥ 2 undergoing aortic valve and root surgery, the prevalence of MR grade ≥ 2 was 23%. Lower LV ejection fraction and larger left atrial volume were independently associated with MR grade ≥ 2.

Changes of Mitral Valve Geometry after Percutaneous Edge-to-Edge Mitral Valve Repair: a 4-Dimensional Analysis

Changes of Mitral Valve Geometry after Percutaneous Edge-to-Edge Mitral Valve Repair: a 4-Dimensional Analysis

Efficacy of polymer injection for ischemic mitral regurgitation: persistent reduction of mitral regurgitation and attenuation of left ventricular remodeling.

The aim of this study was to examine the chronic effects of polyvinyl-alcohol (PVA) injection on mitral regurgitation (MR) reduction, mitral valve geometry, and left ventricular (LV) remodeling in a chronic ischemic MR sheep model. Previous studies have demonstrated acute efficacy of PVA hydrogel polymer injection into infarcted myocardium underlying the papillary muscle to relieve MR by papillary muscle repositioning. However, the chronic efficacy of PVA injection in the chronic infarction setting remains unclear. Sixteen sheep developed chronic MR 8 weeks after induced inferoposterior myocardial infarction. Ten consecutive sheep underwent PVA injection (PVA group) and 6 sheep served as control subjects with saline injection. Epicardial 2-/3-dimensional echocardiography was performed at the baseline, chronic MR (pre-injection), and sacrifice (8 weeks after injection) stages. Both groups were comparable at the baseline and chronic MR stages. At sacrifice, MR decreased from moderate to trace or mild (vena contracta: 0.17 ± 0.08 cm vs. 0.56 ± 0.10 cm, p < 0.001) in the PVA group but progressed to moderate to severe in the control group. End-systolic and -diastolic volumes remained stable in the PVA group but increased significantly in the control group (both p < 0.05). At sacrifice, compared with the control group, the PVA group had significantly less left ventricular remodeling (end-systolic volume: 41.1 ± 10.4 ml vs. 55.9 ± 12.4 ml, p < 0.05), lower MR severity (vena contracta: 0.17 ± 0.08 cm vs. 0.60 ± 0.14 cm, p < 0.01), and favorable changes in mitral valve geometry. Polymer injection in a chronic ischemic MR model results in persistent reduction of MR and attenuation of continued left ventricular remodeling over 8 weeks of follow-up.