Annular Height-to-Commissural Width Ratio of Annulolasty Rings In Vivo

An axis-specific mitral annuloplasty ring eliminates mitral regurgitation allowing mitral annular motion in an ovine model

INTRODUCTION

Current mitral annuloplasty rings fail to restrict the anteroposterior distance while allowing dynamic mitral annular changes. We designed and manufactured a mitral annuloplasty ring that demonstrated axis-specific, selective flexibility to meet this clinical need. The objectives were to evaluate ex vivo biomechanics of this ring and to validate the annular dynamics and safety after ring implantation in vivo.

METHODS

Healthy human mitral annuli (n = 3) were tracked, and motions were isolated. Using the imaging data, we designed and manufactured our axis-specific mitral annuloplasty ring. An ex vivo annular dilation model was used to compare hemodynamics and chordal forces after repair using the axis-specific, rigid, and flexible rings in five porcine mitral valves. In vivo, axis-specific (n = 6), rigid (n = 6), or flexible rings (n = 6) were implanted into male Dorset sheep for annular motion analyses. Five additional animals receiving axis-specific rings survived for up to 6 months.

RESULTS

Here we show the axis-specific, rigid, and flexible rings reduced regurgitation fraction to 4.7 ± 2.7%, 2.4 ± 3.2%, and 17.8 ± 10.0%, respectively. The axis-specific ring demonstrated lower average forces compared to the rigid ring (p = 0.046). Five animals receiving axis-specific rings survived for up to 6 months, with mitral annular motion preserved in vivo. Mature neoendocardial tissue coverage over the device was found to be complete with full endothelialization in all animals.

CONCLUSIONS

The axis-specific mitral annuloplasty ring we designed demonstrates excellent capability to repair mitral regurgitation while facilitating dynamic mitral annular motion. This ring has tremendous potential for clinical translatability, representing a promising surgical solution for mitral regurgitation.

Impact of Recurrent Mitral Regurgitation on Left Ventricular Mass Regression and Cardiac Events following Mitral Valve Repair

BACKGROUND

Mitral valve regurgitation results in volume overload, followed by left ventricular remodeling. Variation of reverse remodeling following mitral repair influences the clinical outcomes. We aimed to evaluate the association between recurrent mitral regurgitation and mass regression following mitral valve repair and the impact on major adverse cardiovascular events.

METHODS

A retrospective cohort study was conducted on 164 consecutive patients with severe mitral regurgitation who underwent elective mitral valve repair. Subgroups were classified based on the presence of recurrent mitral regurgitation exceeding moderate severity. The hemodynamic parameters were evaluated according to geometry, mass, and function with Doppler echocardiography before and after surgery. Cox regression analysis was performed to evaluate the association between hemodynamics and mass regression and clinical outcomes.

RESULTS

The results for MR indicated 110 cases with non-recurrent MR and 54 with recurrent MR, along with 31 major adverse cardiovascular events. The tracked echocardiographic results revealed less reduction in dimension and volume, along with less mass regression in the recurrent MR subgroup. Significant differences were revealed in the relative change of the LV end-diastolic volume index and relative mass regression between subgroups. The relative change in the LVEDVI was proportionally correlated with relative mass regression. Cox regression analysis identified correlations with major adverse cardiovascular events, including suture annuloplasty, recurrent mitral regurgitation, tracked LV mass, relative LV mass regression, and systolic dysfunction.

CONCLUSION

LV mass regression and relative change of the LV end-diastolic volume could be risk predictors of recurrent mitral regurgitation. The extent of LV mass regression is correlated with adverse cardiac events.

Mitral Valve Translocation: Optimization of Patch Geometry in an Ex Vivo Model of Secondary Mitral Regurgitation

Optimal translocation patch width for functional mitral regurgitation (FMR) treatment was evaluated in an air-filled ex vivo system. FMR was created in 19 isolated swine hearts by annular dilation and papillary muscle displacement. Frustum-shaped pericardial patches of varying widths (Group 1 = 0.5 cm; Group 2 = 1.0 cm; Group 3 = 1.5 cm) were implanted and imaged via a 3D-structured light scanner. Median leaflet coaptation decreased (P < 0.001) from 5.5 ± 2.0 mm at baseline to 2.4 ± 1.3 mm following FMR creation. Translocation repair increased coaptation length over FMR levels by 2.2 mm in Group 1 (P < 0.001), 4.6 mm in Group 2 (P < 0.001), and 4.7 mm in Group 3 (P < 0.001). After repair, no significant differences were found between groups for annular height, circularity index, tenting height, tenting area, and non-coapting surface area. The supranormal coaptation and minimal valve geometric changes support using a 1.0- or 1.5-cm translocation patch for FMR treatment. Implantation of a 1.0-cm or 1.5-cm circumferential pericardial patch (mitral valve translocation) increases leaflet coaptation length without significantly altering valve geometry.

Three-Dimensional Mitral Valve Morphology in Children and Young Adults With Marfan Syndrome

BACKGROUND

Mitral valve (MV) prolapse is common in children with Marfan syndrome (MFS) and is associated with varying degrees of mitral regurgitation (MR). However, the three-dimensional (3D) morphology of the MV in children with MFS and its relation to the degree of MR are not known. The goals of this study were to describe the 3D morphology of the MV in children with MFS and to compare it to that in normal children.

METHODS

Three-dimensional transthoracic echocardiography was performed in 27 patients (3-21 years of age) meeting the revised Ghent criteria for MFS and 27 normal children matched by age (±1 year). The 3D geometry of the MV apparatus in midsystole was measured, and its association with clinical and two-dimensional echocardiographic parameters was examined.

RESULTS

Compared with age-matched control subjects, children with MFS had larger 3D annular areas (P < .02), smaller annular height/commissural width ratios (P < .001), greater billow volumes (P < .001), and smaller tenting heights, areas, and volumes (P < .001 for all). In multivariate modeling, larger leaflet billow volume in MFS was strongly associated with moderate or greater MR (P < .01). Intra- and interuser variability of 3D metrics was acceptable.

CONCLUSIONS

Children with MFS have flatter and more dilated MV annuli, greater billow volumes, and smaller tenting heights compared with normal control subjects. Larger billow volume is associated with MR. Three-dimensional MV quantification may contribute to the identification of patients with MFS and other connective tissue disorders. Further study of 3D MV geometry and its relation to the clinical progression of MV disease is warranted in this vulnerable population.

Fully automated software for mitral annulus evaluation in chronic mitral regurgitation by 3-dimensional transesophageal echocardiography

Three-dimensional (3D) transesophageal echocardiography (TEE) is the gold standard for mitral valve (MV) anatomic and functional evaluation. Currently, dedicated MV analysis software has limitations for its use in clinical practice. Thus, we tested here a complete and reproducible evaluation of a new fully automatic software to characterize MV anatomy in different forms of mitral regurgitation (MR) by 3D TEE.Sixty patients were included: 45 with more than moderate MR (28 organic MR [OMR] and 17 functional MR [FMR]) and 15 controls. All patients underwent TEE. 3D MV images obtained using 3D zoom were imported into the new software for automatic analysis. Different MV parameters were obtained and compared. Anatomic and dynamic differences between FMR and OMR were detected. A significant increase in systolic (859.75 vs 801.83 vs 607.78 mm; P = 0.002) and diastolic (1040.60 vs. 1217.83 and 859.74 mm; P < 0.001) annular sizes was observed in both OMR and FMR compared to that in controls. FMR had a reduced mitral annular contraction compared to degenerative cases of OMR and to controls (17.14% vs 32.78% and 29.89%; P = 0.007). Good reproducibility was demonstrated along with a short analysis time (mean 4.30 minutes).Annular characteristics and dynamics are abnormal in both FMR and OMR. Full 3D software analysis automatically calculates several significant parameters that provide a correct and complete assessment of anatomy and dynamic mitral annulus geometry and displacement in the 3D space. This analysis allows a better characterization of MR pathophysiology and could be useful in designing new devices for MR repair or replacement.

Role of Mitral Annulus Diastolic Geometry on Intraventricular Filling Dynamics

The mitral valve (MV) is a bileaflet valve positioned between the left atrium and ventricle of the heart. The annulus of the MV has been observed to undergo geometric changes during the cardiac cycle, transforming from a saddle D-shape during systole to a flat (and less eccentric) D-shape during diastole. Prosthetic MV devices, including heart valves and annuloplasty rings, are designed based on these two configurations, with the circular design of some prosthetic heart valves (PHVs) being an approximation of the less eccentric, flat D-shape. Characterizing the effects of these geometrical variations on the filling efficiency of the left ventricle (LV) is required to understand why the flat D-shaped annulus is observed in the native MV during diastole in addition to optimizing the design of prosthetic devices. We hypothesize that the D-shaped annulus reduces energy loss during ventricular filling. An experimental left heart simulator (LHS) consisting of a flexible-walled LV physical model was used to characterize the filling efficiency of the two mitral annular geometries. The strength of the dominant vortical structure formed and the energy dissipation rate (EDR) of the measured fields, during the diastolic period of the cardiac cycle, were used as metrics to quantify the filling efficiency. Our results indicated that the O-shaped annulus generates a stronger (25% relative to the D-shaped annulus) vortical structure than that of the D-shaped annulus. It was also found that the O-shaped annulus resulted in higher EDR values throughout the diastolic period of the cardiac cycle. The results support the hypothesis that a D-shaped mitral annulus reduces dissipative energy losses in ventricular filling during diastole and in turn suggests that a symmetric stent design does not provide lower filling efficiency than an equivalent asymmetric design.

Mitral valve repair over five decades

It has become evident that mitral valve (MV) repair is the preferable treatment for the majority of patients presenting with severe mitral regurgitation (MR). This success clearly testifies that the surgical procedure is accessible, reproducible and is carrying excellent long-lasting results. From the pre-extracorporeal circulation's era to the last percutaneous approaches, a large variety of techniques have been proposed to address the different features of MV diseases. This article aimed at reviewing chronologically the development of these dedicated techniques through their origins and the debates that they generated in the literature.

Asymmetric versus symmetric tethering patterns in ischemic mitral regurgitation: geometric differences from three-dimensional transesophageal echocardiography

BACKGROUND

Ischemic mitral regurgitation (IMR) results from mitral leaflet tethering from left ventricular remodeling. Heterogeneity in local or global left ventricular remodeling can result in differential tethering patterns and affect mitral valve function and the degree of mitral regurgitation. The aims of this study were to compare mitral valve geometry in asymmetric and symmetric tethering patterns using three-dimensional transesophageal echocardiography and to examine the impact of tethering pattern on IMR severity.

METHODS

Sixty-two patients with moderate or greater IMR underwent three-dimensional transesophageal echocardiography for the assessment of mitral valve geometry. Symmetric and asymmetric tethering patterns were determined by mitral regurgitation jet direction and coaptation of the mitral leaflets. The ratio of posterior to anterior leaflet tethering angle was a measure of tethering pattern (the higher the ratio, the more asymmetric the pattern). Overall tethering degree was assessed by tenting volume (TV).

RESULTS

Compared with the symmetric group, the asymmetric group had less annular dilatation, greater annular heights (10.3 ± 1.9 vs 8.5 ± 1.9 mm, P < .01), greater ratios of posterior to anterior leaflet tethering angle (3.19 ± 0.88 vs 1.95 ± 0.46, P < .01), and smaller TVs with more posterior displacement of the coaptation line. Vena contracta normalized to TV was greater in the asymmetric group (0.38 ± 0.24 vs 0.19 ± 0.13 cm/mL, P < .01). Multivariate analysis showed that both ratio of posterior to anterior leaflet tethering angle (β = 0.46, P < .001) and TV (β = 0.41, P = .001) were predictors of IMR severity.

CONCLUSIONS

Differences in mitral valve geometry are observed between asymmetric and symmetric tethering patterns in IMR. IMR degree is affected by both the pattern of tethering and the total degree of tethering. For the same degree of tethering, an asymmetric pattern is associated with increased MR severity. The pattern of mitral leaflet tethering may be considered in therapeutic decision making.

Saddle-shaped mitral valve annuloplasty rings improve leaflet coaptation geometry

OBJECTIVES

The mitral valve annulus naturally conforms to a saddle shape in systole. This configuration is believed to put the leaflets into a lower-energy equilibrium with the annulus and subvalvular apparatus. Conventional flat annuloplasty rings restrict posterior leaflet motion, which may result in a "monocusp" valve, affecting valvular stress distribution. It is hypothesized that saddle-shaped annuloplasty rings cause less distortion of the physiologic leaflet geometry than do flat rings.

METHODS

Twelve pigs were studied in an acute setting with 3-dimensional echocardiography and sonomicrometry before and after implantation of rigid flat (n = 5) and saddle-shaped (n = 7) annuloplasty rings. The rings were true sized to the annulus with equal anterior-posterior and commissure-commissure circumferential dimensions. The saddle-shaped rings had an annular height to commissural width ratio of 15%.

RESULTS

Saddle-shaped rings maintained both leaflets operational (P < .01). Flat rings made the posterior leaflet immobile and the anterior leaflet aligned flat along the annulus in systole, effectively resulting in monoleaflet function. The average distance from the papillary muscle tips to the posterior annulus decreased by 2.4 ± 0.4 mm after flat ring implantation (P < .01).

CONCLUSIONS

Saddle-shaped annuloplasty rings provide better leaflet coaptation geometry than do flat rings by not hoisting the papillary muscles toward the posterior annulus through the commissural chordae, allowing greater leaflet mobility. This entails a potentially beneficial impact on valvular stress distribution that could affect durability of the repaired valve.

Mitral Valve Repair: Past, Present, and Future

Mitral valve repair is the operation of choice for mitral valve regurgitation, with appropriate selection. Studies have shown that mitral repair is associated with a decrease in both long-term thromboembolic complications and mortality. Since its initial description, various selection criteria and techniques of mitral valve repair have been discussed in the literature. This review serves as a synopsis of the previous achievements, present status, and possible future directions of mitral valve repair, specifically from an Asian perspective. Vast experience has been amassed in understanding mitral valve pathophysiology, and excellent surgical treatments for mitral regurgitation have been developed. With the efforts of pioneers in the field of mitral valve repair, standard surgical treatment strategies have been proven to restore the life-expectancy of patients with degenerative mitral regurgitation to that of the age-adjusted population. Minimally invasive techniques of mitral valve repair further reduce access trauma, and could potentially benefit patients previously excluded from conventional surgery.

Patient-specific modeling and quantification of the aortic and mitral valves from 4-D cardiac CT and TEE

As decisions in cardiology increasingly rely on noninvasive methods, fast and precise image processing tools have become a crucial component of the analysis workflow. To the best of our knowledge, we propose the first automatic system for patient-specific modeling and quantification of the left heart valves, which operates on cardiac computed tomography (CT) and transesophageal echocardiogram (TEE) data. Robust algorithms, based on recent advances in discriminative learning, are used to estimate patient-specific parameters from sequences of volumes covering an entire cardiac cycle. A novel physiological model of the aortic and mitral valves is introduced, which captures complex morphologic, dynamic, and pathologic variations. This holistic representation is hierarchically defined on three abstraction levels: global location and rigid motion model, nonrigid landmark motion model, and comprehensive aortic-mitral model. First we compute the rough location and cardiac motion applying marginal space learning. The rapid and complex motion of the valves, represented by anatomical landmarks, is estimated using a novel trajectory spectrum learning algorithm. The obtained landmark model guides the fitting of the full physiological valve model, which is locally refined through learned boundary detectors. Measurements efficiently computed from the aortic-mitral representation support an effective morphological and functional clinical evaluation. Extensive experiments on a heterogeneous data set, cumulated to 1516 TEE volumes from 65 4-D TEE sequences and 690 cardiac CT volumes from 69 4-D CT sequences, demonstrated a speed of 4.8 seconds per volume and average accuracy of 1.45 mm with respect to expert defined ground-truth. Additional clinical validations prove the quantification precision to be in the range of inter-user variability. To the best of our knowledge this is the first time a patient-specific model of the aortic and mitral valves is automatically estimated from volumetric sequences.

Mitral annular dynamics in myxomatous valve disease: new insights with real-time 3-dimensional echocardiography

BACKGROUND

Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion.

METHODS AND RESULTS

Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annular dimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software. Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1+/-0.1 mm; P=0.73; 95% confidence interval, +/-4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P<0.05). Normal annulus displayed early-systolic anteroposterior (P<0.001) and area (P=0.04) contraction, increased height (P<0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15+/-1% to 21+/-1%; P<0.001), whereas intercommissural diameter was unchanged (P=0.30). In contrast, MVD showed early-systolic intercommissural dilatation (P=0.02) and no area contraction (P=0.99), height increase (P=0.11), or saddle-shape deepening (P=0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged (P<0.04) as a result of persistent intercommissural widening (P<0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation (P=0.30).

CONCLUSIONS

Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annular decoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

Saddle shape of the mitral annulus reduces systolic strains on the P2 segment of the posterior mitral leaflet

BACKGROUND

The three-dimensional saddle shape of the mitral annulus is well characterized in animals and humans, but the impact of annular nonplanarity on valve function or mechanics is poorly understood. In this study, we investigated the impact of the saddle shaped mitral annulus on the mechanics of the P2 segment of the posterior mitral leaflet.

METHODS

Eight porcine mitral valves (n = 8) were studied in an in-vitro left heart simulator with an adjustable annulus that could be changed from flat to different degrees of saddle. Miniature markers were placed on the atrial face of the posterior leaflet, and leaflet strains at 0%, 10%, and 20% saddle were measured using dual-camera stereophotogrammetry. Averaged areal strain and the principal strain components are reported.

RESULTS

Peak areal strain magnitude decreased significantly from flat to 20% saddle annulus, with a 78% reduction in the measured strain over the entire P2 region. In the radial direction (annulus free edge), a 44.4% reduction in strain was measured, whereas in the circumferential direction (commissure-commissure), a 34% reduction was measured from flat to 20% saddle.

CONCLUSIONS

Nonplanar shape of the mitral annulus significantly reduced the mechanical strains on the posterior leaflet during systolic valve closure. Reduction in strain in both the radial and circumferential directions may reduce loading on the suture lines and potentially improve repair durability, and also inhibit progression of valve degeneration in patients with myxomatous valve disease.

Mitral annular hinge motion contribution to changes in mitral septal-lateral dimension and annular area

OBJECTIVE

The mitral annulus is a dynamic, saddle-shaped structure consisting of fibrous and muscular regions. Normal physiologic mechanisms of annular motion are incompletely understood, and more complete characterization is needed to provide rational basis for annuloplasty ring design and to enhance clinical outcomes.

METHODS

Seventeen sheep had radiopaque markers implanted; 16 around the annulus and 2 on middle anterior and posterior leaflet edges. Four-dimensional marker coordinates were acquired with biplanar videofluoroscopy at 60 Hz. Hinge angle was quantified between fibrous and muscular annular planes, with 0 degrees defined at end diastole, to characterize its contribution to alterations in mitral septal-lateral dimension and 2-dimensional total annular area throughout the cardiac cycle.

RESULTS

During isovolumic contraction (pre-ejection), hinge angle abruptly increased, reaching maximum (steepest saddle shape, change 18 degrees +/- 13 degrees ) at peak left ventricular pressure. During ejection, hinge angle did not change; it then decreased during early filling (change 2 degrees +/- 2 degrees ). Septal-lateral dimension and total area paralleled hinge angle dynamics and leaflet distance (anterior to posterior marker). Pre-ejection septal-lateral reduction was 13% +/- 7% (3.3 +/- 1.5 mm) from 9% muscular dimension fall and 18 degrees +/- 13 degrees hinge angle increase.

CONCLUSIONS

Pre-ejection increase in hinge angle contributes substantially to septal-lateral and total area reduction, facilitating leaflet coaptation. Semirigid annuloplasty rings or partial bands may preserve hinge motion, but possible recurrent annular dilatation could result in recurrent mitral regurgitation. Long-term clinical studies are required to determine who might benefit most from preserving intrinsic hinge motion without compromising repair durability.

Toward the development of a fully elastic mitral ring: preliminary, acute, in vivo evaluation of physiomechanical behavior

OBJECTIVES

The optimal repair of functional mitral regurgitation is still debated. No device is able to simultaneously abolish mitral regurgitation and replicate natural mitral annular dynamics. We have tested a fully elastic mitral ring in an acute animal study with the purpose of evaluating (1) ring design and implantation technique, (2) elastic performance, and (3) acute effects on the native mitral annulus.

METHODS

Ten healthy sheep underwent surgical implantation of mitral devices, the elastic component of which is represented by a helicoid metallic spring. Preimplantation and postimplantation echocardiographic parameter measurements to evaluate annular dynamics and ventricular function comprise mitral annular motion, systolic tissue Doppler imaging peak wave, transmitral pressure gradient, peak transmitral flow velocity, and ejection fraction. Postimplantation angiographic analysis allowed measurement of the mitral annular area and perimeter variations by means of segmentation of the radiopaque mitral device contour.

RESULTS

No significant difference in terms of ejection fraction (P = .13) and systolic tissue Doppler imaging peak wave (P = .87) was found before and after implantation. Mitral annular motion (1.16 cm) was preserved. The percentage of systolic annular reduction derived from angiographic analysis was 14.1% (range, 7.7%-19.7%) in terms of area and 7.2% (range, 4.9%-10.0%) in terms of perimeter.

CONCLUSIONS

A mitral elastic ring, implantable by using a standard technique, acutely preserves mitral annular dynamics, allowing area and perimeter changes. Further chronic study is needed to verify the biocompatibility and durability of the device.

The influence of annuloplasty ring geometry on mitral leaflet curvature

BACKGROUND

The effect of mitral leaflet curvature on stress reduction is an important mechanism in optimizing valve function. We hypothesize that annuloplasty ring shape could directly influence leaflet curvature and, potentially, repair durability. We describe an echocardiographically based methodology for quantifying mitral valve geometry and its application to the characterization of ovine mitral valve geometry before and after implantation of an annuloplasty ring.

METHODS

Multiple mitral annular and leaflet geometric variables were calculated for 8 naïve adult male sheep using real-time three-dimensional echocardiographic images. These indexes were recalculated after annuloplasty using a 30-mm Carpentier-Edward Physio ring (n = 4; Edwards Lifesciences, Irvine, CA) or a 30-mm saddle ring (n = 4).

RESULTS

After implantation of the Physio ring, the annular height to commissural width ratio (AHCWR) decreased from 19.4% +/- 2.3% to 11.1% +/- 2.5% (p = 0.06). After implantation of the saddle ring, AHCWR increased from 19.6% +/- 1.3% to 24.3% +/- 1.3% (p < 0.05). Statistically significant increases in three-dimensional Gaussian curvature occurred after implantation within six defined leaflet regions (A1 to A3, P1 to P3) of the saddle ring but only within the P1 and P3 leaflet regions with the Physio ring.

CONCLUSIONS

Annuloplasty ring shape affects leaflet curvature. Implantation of a saddle ring reflecting normal human annular geometry augmented ovine annular nonplanarity and increased three-dimensional leaflet curvature across the entire mitral valve surface. The Physio ring decreased annular nonplanarity and increased leaflet curvature only across limited regions of the posterior leaflet. These findings confirm the hypothesis that ring design influences leaflet curvature.

Echocardiographic Follow-up of Tricuspid Annuloplasty with a New Three-Dimensional Ring in Patients with Functional Tricuspid Regurgitation

BACKGROUND

A new tricuspid valve (TV) annuloplasty system, the MC3 ring, includes a three-dimensional structure designed to remodel the TV annulus and preserve physiologic annular function.

PURPOSE

We investigated the early- and mid-term outcomes of TV annuloplasty with the MC3 ring.

METHODS

A total of 136 patients with functional tricuspid regurgitation (TR) had two-dimensional echocardiography before and 5 +/- 5 days after TV annuloplasty with the MC3 ring. Twenty-eight patients were followed for more than 1 year after surgery. Echocardiography was used to assess response to surgical therapy, including measures of cardiac function and geometry and identification of factors predisposing one to recurrent TR.

RESULTS

TR severity was improved early after surgery (P < .001). At 5 days after surgery, 16% had TR graded greater than moderate; among patients followed more than 1 year, this figure was 14%. Postoperative TR severity was associated with preoperative TR severity and tethering height.

CONCLUSION

TV annuloplasty with the new physiologic MC3 ring is effective for the management of TR and may be superior to conventional techniques. However, patients with extensive leaflet tethering (>1.0 cm) require additional maneuvers to ensure valve competence.