Undersized Annuloplasty Research Articles

The Critical Biomechanics of Aortomitral Angle and Systolic Anterior Motion: Engineering Native Ex Vivo Simulation.

Systolic anterior motion (SAM) of the mitral valve (MV) is a complex pathological phenomenon often occurring as an iatrogenic effect of surgical and transcatheter intervention. While the aortomitral angle has long been linked to SAM, the mechanistic relationship is not well understood. We developed the first ex vivo heart simulator capable of recreating native aortomitral biomechanics, and to generate models of SAM, we performed anterior leaflet augmentation and sequential undersized annuloplasty procedures on porcine aortomitral junctions (n = 6). Hemodynamics and echocardiograms were recorded, and echocardiographic analysis revealed significantly reduced coaptation-septal distances confirming SAM (p = 0.003) and effective manipulation of the aortomitral angle (p < 0.001). Upon increasing the angle in our pathological models, we recorded significant increases (p < 0.05) in both coaptation-septal distance and multiple hemodynamic metrics, such as aortic peak flow and effective orifice area. These results indicate that an increased aortomitral angle is correlated with more efficient hemodynamic performance of the valvular system, presenting a potential, clinically translatable treatment opportunity for reducing the risk and adverse effects of SAM. As the standard of care shifts towards surgical and transcatheter interventions, it is increasingly important to better understand SAM biomechanics, and our advances represent a significant step towards that goal.

Papillary Muscle Relocation in Secondary Mitral Regurgitation: Midterm Outcomes

Background: Mitral valve repair in secondary mitral regurgitation is still uncertain as the chance of recurrence is approximately 30 percent after solely undersized annuloplasty. Some procedures adding to the subvalvular level are proposed to alleviate the recurrent rate. This study was to evaluate the clinical and echocardiographic outcomes of papillary muscle relocation plus undersized ring in secondary mitral regurgitation (2nd MR). Methods: Medical records of moderate to severe 2nd MR with tethering depth of more than 1 cm patients who underwent papillary muscle relocation plus undersized ring from 2014 to 2020 were reviewed. Clinical and echocardiographic parameters before and after operation were analyzed. Results: Thirty-two patients were included during the 6-year period. There was no perioperative mortality. Two patients died at one year from ischemic stroke and car accidents with overall 5-year survival of 93.7%. All patients were in NYHA class I and II with MR grading as trivial or mild at a median follow-up of 33 months. Postoperative mean tenting depth, area and posterior leaflet angle decreased remarkably from 1.18 cm, 2.61 cm2 and 46.5 degree to 0.65 cm, 1.22 cm2 and 28.6 degree, respectively (p 0.001, 0.02, and 0.01). Moreover, left ventricular function and remodeling were also notably improved (EF; 38.2% vs 49.1%: p = 0.018, LVEDD; 62.8 vs 54.6 mm: p = 0.005, LVESD; 50.2 vs 42.4 mm: p = 0.01). Conclusions: Papillary muscle relocation combined with undersized annuloplasty improved mid-term clinical outcomes. Apart from reduction of recurrent MR rate, restoration of mitral configuration and reverse LV remodeling could be the effect of adding subvalvular correction in this pathology.

Papillary muscle approximation reduces systolic tethering forces and improves mitral valve closure in the repair of functional mitral regurgitation

BackgroundUndersizing mitral annuloplasty (UMA) to repair functional mitral regurgitation (FMR) lacks durability, as it forces leaflet coaptation without relieving the subleaflet tethering forces. In this biomechanical study, we demonstrate that papillary muscle approximation (PMA) before UMA can drastically relieve tethering forces and improve valve function, without the need for significant annular downsizing. MethodsAn ex vivo model of FMR was used, in which pig mitral valves were geometrically perturbed to induce FMR, and the repairs were performed. Nine pig mitral valves were studied in the following sequence: normal (baseline), FMR, true-sized annuloplasty to 30 mm (true-sized ring [TSR]), and undersized annuloplasty to 26 mm (down-sized ring [DSR]), along with concomitant PMA at both ring sizes. Mitral regurgitation, valve kinematics, and chordal forces were measured and compared among the groups. ResultsFMR geometry induced a mean regurgitant fraction of 16.31 ± 7.33% compared with 0% at baseline. TSR reduced the regurgitant fraction to 6.05 ± 5.63%, whereas DSR reduced it to 5.06 ± 6.76%. The addition of PMA before the use of these rings reduced the mean regurgitant fraction to 3.87 ± 6.79% with the TSR (TSR + PMA) and 3.71 ± 6.25% with the DSR (DSR + PMA). Mean peak anterior and posterior marginal chordal forces were elevated to 0.09 ± 0.1 N and 0.12 ± 0.1 N, respectively, with FMR and were not reduced by annuloplasty of either sizes. The addition of PMA significantly reduced these forces to 0.23 ± 0.02 N and 0.51 ± 0.04 N. ConclusionsThis biomechanical study demonstrates that PMA relieves tethering forces, and concomitantly with annuloplasty it mobilizes the leaflets to achieve physiological valve closure. Such a result could be achieved without the need for extensive annular downsizing.

Non-systematic review of the results of using the technique of secondary chords cutting in ischemic mitral insufficiency

The article presents a non-systematic literature review aimed at studying the efficacy and safety of using the technique of resection of secondary chords in ischaemic mitral insufficiency. The review includes studies comparing the use of an isolated undersized ring annuloplasty and undersized ring annuloplasty with chordal cutting. This study is an analysis of publications devoted to the surgical treatment of patients with ischaemic mitral insufficiency (type IIIb according to A. Carpentier classification). Intervention on the subvalvular structures was of interest, particularly the use of a chordal cutting technique in combination with undersized ring annuloplasty versus isolated undersized ring annuloplasty.The Patient Intervention Comparison Outcome (PICO) strategy was used to find articles. During the initial search, 72 articles were selected, of which 36 articles corresponded to the purpose of the search. After analysing the headings and abstracts, 14 articles were selected according to the inclusion criteria. Full-text copies were obtained for all of them. The review design included retrospective cohort studies. Articles in which the assessment of the effectiveness and safety of the technique was not the main topic of the study were excluded from the analysis. Samples of three articles were formed after reviewing and analysing the texts.The results of the study found that the implementation of the combined operation—undersized ring annuloplasty plus secondary chordal cutting—is significantly more effective in comparison with an isolated undersized ring annuloplasty.Received 28 July 2020. Revised 6 October 2020. Accepted 7 October 2020.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

Abstract 16874: Papillary Muscle Approximation Relieves Tethering Forces and Improves Systolic Mitral Valve Kinematics in an Ex-Vivo Model of Functional Mitral Regurgitation

Introduction: Undersizing annuloplasty (UA), which is the current standard to correct functional mitral regurgitation (FMR) is effective, but the resulting unphysiological systolic geometry causes FMR recurrence. On the other hand, papillary muscle approximation (PMA), a sub-annular technique, reduces inter-papillary separation and tethering forces, mobilizing the leaflets. Objective: To investigate the effect of PMA on mitral valve tethering forces and systolic coaptation geometry, compared to UA. Methods: A left heart model with pig mitral valves was used to create a tethered mitral valve geometry and to perform surgical repairs ( Fig. A ). Mitral valve geometry, and marginal and strut chordal forces acting on both leaflets were measured. Eight individual pig valves (n=8) were studied, with hemodynamic and mechanics data acquired at normal geometry (BASELINE) ( Fig. B) , after tethering (FMR) ( Fig. C) , undersizing annuloplasty (UA) to size 34 (Edwards Lifesciences Physio ring) ( Fig. D) , papillary muscle approximation (PMA), and combination (PMA+UA). Results: Tenting height, which increased after FMR, was least with PMA (0.46 cm± 0.21) and PMA+UA (0.50± 0.16) but remained significantly high with UA (0.73±0.21, p=0.03) ( Fig. E ). Excursion angles of anterior and posterior leaflets were restored close to baseline values after PMA and PMA+UA but remained significantly tethered after UA ( Fig. F &amp; G ). Tethering of the valve increased the strut and marginal chordae forces from 0.47 and 0.14 N to 0.89 and 0.21 N, an increase of 89% and 50% respectively. PMA reduced the forces by 47% and 34%, and PMA+UA reducing it by 43% and 34%to 0.51 while UA only reduced it by 15% and 20% ( Fig. H &amp; I ). Conclusion: PMA significantly reduced the tethering forces on both marginal and strut chordae of both leaflets. Decrease in tethering forces restored the physiologically favorable valve geometry enabling better leaflet mobility and coaptation compared to UA.

Abstract 16801: Papillary Muscle Tip Approximation in Repair of Ischemic Mitral Regurgitation in a Chronic Swine Model

Introduction: Mitral valve (MV) repair with undersized annuloplasty (UMA) for ischemic mitral regurgitation (IMR) is being abandoned in favor of valve replacement (MVR) following CTSN trial results. However, in patients with durable repair, survival and left ventricular function (LVF) were significantly better than MVR. Achieving a durable repair with UMA is challenging as it draws leaflets away from papillary muscle (PM) insertions, causing unphysiological tethering and unicuspid configuration that fails (FigA-B). Hypothesis: Drawing PM tips together with an approximating stitch (PMT-A) can relieve leaflet tethering and enable better repair (FigC). A chronic swine model of IMR was used to compare effects of isolated PMT-A, UMA and PMT-A+UMA on MV and LV at 3 months post surgery. Methods: Twenty-five farm swine underwent catheterization and occlusion of left circumflex artery, resulting in postero-lateral myocardial infarction (MI). Two months after MI, IMR severity of &gt;2+ was confirmed on echo, and animals underwent one of the 3 repairs: PMT-A (n=6), UMA (n=8), PMT-A+UMA (n=11). Echo was performed postoperatively and repeated with MRI at 3 months (FigD). MV kinematics, coaptation geometry, and LVF were assessed. Results: IMR was eliminated after all repairs and did not recur through the study. Annulus continued to grow after PMT-A, but not in UMA or PMT-A+UMA group (FigE1) without increasing severity of IMR. Compared to prerepair, tenting depth was significantly reduced only in PMT-A and PMT-A+UMA groups (FigE2). Both leaflet excursion angles (diastolic minus systolic angles) increased after PMT-A, but not in other groups (FigE3-4). LV size and LVF was similar between groups, confirming that PMT-A did not perturb diastolic filling. Conclusions: In this model of IMR, PMT-A improved leaflet mobility, compared to isolated UMA or PMT-A+UMA. PMT-A is a simple technique that can potentially improve durability of MV repair by restoring valvular kinematics.

Reconstructive operations on subvalvular structures of the mitral valve during remodelling of the left ventricle. Papillary muscle interventions

The optimal treatment strategy for secondary mitral regurgitation of type IIIb (A. Carpentier classification) remains debatable. The use of a standard surgical technique for treating secondary mitral regurgitation and undersized ring annuloplasty demonstrates suboptimal results in several patients (about 30% of the patients exhibit postoperative hemodynamically significant mitral regurgitation with the absence of effective reverse remodelling of the left ventricle). Such suboptimal results are associated with the unification of only the mitral valve reconstruction technique, irrespective of the state of the left ventricle (degree of dysfunction, dilatation, tethering/tenting, and papillary muscle displacement); this is not entirely justified because of the disease complexity (valve and ventricular), and it is crucial to influence both the components of the disease. Particularly, modern researchers are inclined toward the need of using additional reconstructive interventions on the subvalvular structures that contribute to a more effective reverse remodelling of the left ventricle.Here, we present a review of recent studies on the surgical treatment of functional mitral insufficiency of type IIIb (A. Carpentier classification) with effects on the subvalvular structures (pupillary muscle relocation and approximation).Revised 19 April 2020. Revised 5 May 2020. Accepted 28 May 2020.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.

Intraoperative post-annuloplasty three-dimensional valve analysis does not predict recurrent ischemic mitral regurgitation

BackgroundHigh ischemic mitral regurgitation (IMR) recurrence rates continue to plague IMR repair with undersized ring annuloplasty. We have previously shown that pre-repair three-dimensional echocardiography (3DE) analysis is highly predictive of IMR recurrence. The objective of this study was to determine the quantitative change in 3DE annular and leaflet tethering parameters immediately after repair and to determine if intraoperative post-repair 3DE parameters would be able to predict IMR recurrence 6 months after repair.MethodsIntraoperative pre- and post-repair transesophageal real-time 3DE was performed in 35 patients undergoing undersized ring annuloplasty for IMR. An advanced modeling algorhythm was used to assess 3D annular geometry and regional leaflet tethering. IMR recurrence (≥ grade 2) was assessed with transthoracic echocardiography 6 months after repair.ResultsAnnuloplasty significantly reduced septolateral diameter, commissural width, annular area, and tethering volume and significantly increased all segmental tethering angles (except A2). Intraoperative post-repair annular geometry and leaflet tethering did not differ significantly between patients with recurrent IMR (n = 9) and patients with non-recurrent IMR (n = 26). No intraoperative post-repair predictors of IMR recurrence could be identified.ConclusionsUndersized ring annuloplasty changes mitral geometry acutely, exacerbates leaflet tethering, and generally fixes IMR acutely, but it does not always fix the delicate underlying chronic problem of continued left ventricular dilatation and remodeling. This may explain why pre-repair 3D valve geometry (which reflects chronic left ventricular remodeling) is highly predictive of recurrent IMR, whereas immediate post-repair 3D valve geometry (which does not completely reflect chronic left ventricular remodeling anymore) is not.

Bilateral papillary muscle repositioning: successful repair of functional mitral regurgitation in dilative cardiomyopathy.

Functional mitral regurgitation (FMR) in patients with non-ischaemic dilative cardiomyopathy (DCM) is associated with heart failure and poor outcome. Aggressively undersized annuloplasty as an annular solution for a ventricular problem ameliorates heart failure but may be associated with recurrent FMR and does not improve survival. We sought to analyse if moderately undersized annuloplasty with repositioning of both papillary muscles can lead to improved valve stability and outcome in patients with DCM and FMR. In 66 patients with DCM-associated FMR (age 66 ± 12 years, ejection fraction 29 ± 6% and mean pulmonary artery pressure 35 ± 11 mmHg) and severe leaflet tethering (tenting height ≥10 mm) bilateral papillary muscle repositioning was added to moderately undersized ring annuloplasty (median size 30 mm). Concomitant surgery included tricuspid valve repair in 86% of patients and atrial ablation in 44%. The early mortality rate was 9%. Overall 5-year freedom from all-cause death, left ventricular assist device implantation or heart transplant was 58% (95% confidence interval 45-71%). Six patients underwent reoperation (redo repair n = 4). Reverse remodelling was observed during follow-up in 66% of patients with decreasing left ventricular end-diastolic diameters (66 ± 5 to 61 ± 12 mm; P < 0.001) and left ventricular end-systolic diameters (56 ± 9 to 51 ± 14 mm; P = 0.001). Subgroup analyses (partial versus complete ring, preoperative left ventricular end-diastolic diameters <65 mm vs left ventricular end-diastolic diameter ≥65 mm) documented similar survival rates. A competing risks regression analysis identified cerebral vascular disease (P = 0.01), use of a partial ring (P = 0.03) and absence of tricuspid valve repair (P = 0.03) as independent predictors of death. The combination of bilateral papillary muscle repositioning and moderately undersized ring annuloplasty leads to stable mid-term repair results and reverse remodelling in patients with DCM and FMR and severe leaflet tethering.

Optimized mitral annuloplasty ring design reduces loading in the posterior annulus

ObjectiveThe study objective was to develop a novel annuloplasty ring with regional flexibility and assess its suture force dynamics in healthy ovine subjects compared with fully rigid or fully flexible rings. MethodsMaterially heterogeneous rings were created with rigid anterior and posterior, and flexible commissural segments. These rings were created to match the geometry of the Profile 3D ring (Medtronic, Minneapolis, Minn). Each ring was instrumented with 10 force transducers to measure cyclic suture forces (FC) and undersized annuloplasty was performed in 6 healthy ovine subjects. Each FC was recorded and examined for cardiac cycles reaching a maximum left ventricular pressure of 100, 125, and 150 mm Hg. FC was compared with previously reported values from fully rigid Profile 3D and fully flexible prototype rings. ResultsRelative to the fully rigid ring, the heterogeneous ring exhibited 48% reduction in FC at its commissural (rigid vs heterogeneous: 1.80 ± 0.94 N vs 0.95 ± 0.52 N; P < .001) and 32% reduction in posterior (1.90 ± 0.92 N vs 1.29 ± 0.91 N; P < .001) regions, but not in its anterior region (2.45 ± 1.21 N vs 2.23 ± 1.22 N; P = .279). Relative to the fully flexible ring, the heterogeneous ring exhibited no significant differences in FC in any region. ConclusionsThe reduced FC of the heterogeneous ring relative to the fully rigid ring suggests a promising approach to reduce suture loading while preserving the annular remodeling capability of fully rigid rings. Future studies in diseased subjects are necessary to explore repair effectiveness of this ring.

Euler’s Elastica-Based Biomechanics of the Papillary Muscle Approximation in Ischemic Mitral Valve Regurgitation: A Simple 2D Analytical Model

Ischemic mitral regurgitation (IMR) occurs as an adverse consequence of left ventricle remodeling post-myocardial infarction. A change in mitral valve configuration with an imbalance between closing and tethering forces underlie this pathological condition. These abnormalities lead to impaired leaflet coaptation and a variable degree of mitral regurgitation, which can in turn influence the ventricular filling status, the heart rhythm and the afterload regardless of the residual ischemic insult. The IMR correction can be pursued through under-sizing mitral annuloplasty and papillary muscle approximation to restore the mitral valve and left ventricle physiological geometry to, consequently, achieve normalization of the engaged physical forces. Because the structures involved undergo extremely large deformations, a biomechanics model based on the Euler’s Elastica –the mitral leaflet– interlaced with nonlinear chordae tendineae anchored on papillary muscles has been constructed to elucidate the interactions between closing and tethering forces. The model takes into account the actual updated geometrical and mechanical features of the valvular and subvalvular apparatuses in physiological and IMR conditions, as well as in case of papillary muscle approximation, finally furnishing ad hoc geometry-based mathematical relations that could be utilised to support—and optimize—the relevant choices in cardiac surgery.

Long-term results of surgical treatment of secondary severe mitral regurgitation in patients with end-stage heart failure: Advantage of prosthesis insertion

Surgical treatment of secondary mitral regurgitation (SMR) is controversial. To analyse outcome after undersizing annuloplasty (UA) and mitral valve replacement (MVR). Consecutive patients operated on for severe SMR, with left ventricular ejection fraction (LVEF)<40% and refractory CHF, were included. Endpoints were in-hospital mortality, mid-term cardiovascular (CV) mortality, evolution of LV variables and recurrence of mitral regurgitation (MR). 59 patients were included (mean age 65±10 years, preoperative LVEF 36±6%; effective regurgitant orifice [ERO] 41±17 mm2), 41 with ischaemic disease: 12 underwent UA and 47 underwent MVR; only eight had concomitant coronary revascularization. In-hospital mortality was 3.3% (8.3% in UA group; 2.1% in MVR group). Eight-year CV mortality was 39±13% (40±18% in UA group; 27±10% in MVR group). Older age (hazard ratio 1.14, 95% confidence interval 1.07 to 1.22; P<0.001) and LV end-systolic diameter (hazard ratio 1.18, 95% confidence interval 1.09 to 1.27; P<0.001) independently predicted CV mortality. LVEF did not change between the preoperative and follow-up transthoracic echocardiograms in the MVR group (36±6% vs. 35±10%; P=0.6) or the UA group (36±5% vs. 31±12%; P=0.09). Conversely, LV end-diastolic diameter decreased significantly in the MVR group (64±8m to 59±9mm; P=0.002), but not in the UA group (61±7m to 64±10mm; P=0.2). Recurrence of significant MR occurred in 81% of patients in the UA group (mean postoperative ERO 19±6 mm2) versus none in the MVR group. Surgical treatment of SMR can be performed with acceptable operative risk and mid-term survival in severe heart failure, even if there is no indication for revascularization. MVR is associated with significant reverse remodelling, and UA with prohibitive risk of MR recurrence.

MitraClip Leads to Less Strain Increase than Undersized Annuloplasty in Ischemic Mitral Regurgitation: A Finite Element Model

Morgan, Ashley MD; Pantoja, Joe L. MD; Weinsaft, Jonathan W. MD; Ge, Liang PhD; Wozniak, Curtis J. MD; Ratcliffe, Mark B. MD Author Information

Minimally Invasive Mitral Valve Annuloplasty With Realignment of Both Papillary Muscles for Correction of Type IIIb Functional Mitral Regurgitation.

Pathophysiological background of type IIIb functional mitral regurgitation (FMR) is a progressively increasing distance between papillary muscle tips and mitral annular plane. Standard surgical treatment of such FMR by means of undersized mitral annuloplasty is associated with a high recurrence rate. We propose a modified subannular maneuver to correct type IIIb FMR while combining undersized annuloplasty with a controlled realignment of both papillary muscles, thereby fixing the distance between mitral annular plane and papillary muscle tips. The differences of this subannular maneuver as compared with the previously published techniques are the following: (1) controlled realignment of both papillary muscles, (2) fixation of the papillary muscles to mitral annulus distance on an annuloplasty ring, and (3) application in a three-dimensional endoscopic minithoracotomy setting. We describe a surgical technique of minimally invasive mitral valve repair performed due to severe type IIIb FMR, which includes a modified subannular maneuver to realign both papillary muscles. Preliminary results of the first 10 patients who underwent this procedure at our institution are presented. There was no in-hospital mortality and follow-up echocardiography (mean ± SD echocardiographic follow-up = 10 ± 6 months) demonstrated stable functional results. Our initial experience indicates that adding of this subannular maneuver to the standard annuloplasty and thereby fixing the distance between papillary muscles and mitral annular plane have a potential to improve results of surgical FMR treatment.

The role of papillary muscle approximation in mitral valve repair for the treatment of secondary mitral regurgitation.

Secondary mitral regurgitation (MR) is present in up to half of patients with dilated cardiomyopathy, and is associated with a poor prognosis. It primarily results from progressive left ventricular remodelling, papillary muscle displacement and tethering of the mitral valve leaflets. Mitral valve repair with an undersized ring annuloplasty is the reparative procedure of choice in the treatment of secondary MR. However, this technique is associated with a 30-60% incidence of recurrent moderate or greater MR at mid-term follow-up, which results in progressive deterioration of left ventricular function and increased morbidity. Combined mitral valve repair and papillary muscle approximation has been applied in order to address both the annular and subvalvular dysfunction that coexist in secondary MR, which include graft and suture-based techniques. Herein, we provide a systematic review of the published literature regarding the technical aspects, clinical application, and outcomes of mitral valve repair with combined ring annuloplasty and papillary muscle approximation for the treatment of secondary MR.

The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

ObjectivesRepair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. MethodsIntraoperative transesophageal 2-dimensional echocardiography and 3-dimensional echocardiography were performed in 50 patients undergoing undersized annuloplasty for ischemic mitral regurgitation. Two-dimensional echocardiography annular diameter and tethering parameters were measured in the apical 2- and 4-chamber views. A customized protocol was used to assess 3-dimensional annular geometry and regional leaflet tethering. Recurrence (grade ≥2) was assessed with 2-dimensional transthoracic echocardiography at 6 months. ResultsPreoperative 2- and 3-dimensional annular geometry were similar in all patients with ischemic mitral regurgitation. Preoperative 2- and 3-dimensional leaflet tethering were significantly higher in patients with recurrence (n = 13) when compared with patients without recurrence (n = 37). Multivariate logistic regression revealed preoperative 2-dimensional echocardiography posterior tethering angle as an independent predictor of recurrence with an optimal cutoff value of 32.0° (area under the curve, 0.81; 95% confidence interval, 0.68-0.95; P = .002) and preoperative 3-dimensional echocardiography P3 tethering angle as an independent predictor of recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84-1.00; P < .001). The predictive value of the 3-dimensional geometric multivariate model can be augmented by adding basal aneurysm/dyskinesis (area under the curve, 0.94; 95% confidence interval, 0.87-1.00; P < .001). ConclusionsPreoperative 3-dimensional echocardiography P3 tethering angle is a stronger predictor of ischemic mitral regurgitation recurrence after annuloplasty than preoperative 2-dimensional echocardiography posterior tethering angle, which is highly influenced by viewing plane. In patients with a preoperative P3 tethering angle of 29.9° or larger (especially when combined with basal aneurysm/dyskinesis), chordal-sparing valve replacement should be strongly considered.

Long-term results of mitral repair in patients with severe left ventricular dysfunction and secondary mitral regurgitation: does the technique matter?

An isolated undersized annuloplasty was used to treat mitral regurgitation (MR) secondary to dilated cardiomyopathy (DCM) if the baseline coaptation depth (CD) was <1 cm. In the presence of significant tethering of the mitral leaflets (CD ≥1 cm), the edge-to-edge (EE) technique was combined with annuloplasty to improve the durability of the repair. The long-term results of this approach are unknown and represent the objective of this study. To obtain long-term outcome data, we included in the study population the first 105 consecutive patients with severe left ventricular dysfunction (ejection fraction 29 ± 6.6%) and secondary MR submitted to mitral valve repair. Forty patients underwent isolated undersized annuloplasty and 65 patients received the EE technique combined with annuloplasty. Preoperative and postoperative data were prospectively entered into a dedicated database. Clinical and echocardiographic follow-ups were performed in our institutional outpatient clinic. Follow-up was 90% complete. The median follow-up time was 7.2 years (interquartile range 4.3;10.4). The longest follow-up time was 16.5 years. A comparative analysis between the annuloplasty group and the EE group was performed. Baseline LV dimensions and function were slightly worse in the EE group, but only the severity of tethering was significantly more pronounced than in the annuloplasty group. Hospital mortality (3 vs 2.5%, P = 1.0) and 10-year overall survival (42 ± 6.7 vs 55 ± 8.5%, P = 0.2) were not significantly different in the EE and annuloplasty group, respectively. Cumulative incidence functions of cardiac death were similar as well (at 10-years, 34.3 ± 8.1 vs 37.9 ± 6.4%, respectively, P = 0.4). At 10 years, cumulative incidence function of recurrence of MR ≥3+ was lower in the EE patients (10.3 ± 4.1 vs 30.8±8.0%, P = 0.01). Isolated annuloplasty [hazard ratio (HR) 4.84, 95% confidence interval (CI) 1.46-16.1, P = 0.01] and residual MR >1+ at hospital discharge (HR 5.25, 95% CI 2.00-13.8, P < 0.001) were significantly related to the development of MR ≥3. Failure of repair was associated with recurrence of New York Heart Association III or IV symptoms (P < 0.001). In patients with end-stage DCM and secondary MR, the association of the EE technique to the undersized annuloplasty significantly decreases the rate of recurrent MR at long-term. This higher repair durability did not translate into a better long-term prognosis in this series.

Preoperative Three-Dimensional Valve Analysis Predicts Recurrent Ischemic Mitral Regurgitation After Mitral Annuloplasty

Valve repair for ischemic mitral regurgitation (IMR) with undersized annuloplasty rings is characterized by high IMR recurrence rates. Patient-specific preoperative imaging-based risk stratification for recurrent IMR would optimize results. We sought to determine if prerepair three-dimensional (3D) echocardiography combined with a novel valve-modeling algorithm would be predictive of IMR recurrence 6 months after repair. Intraoperative transesophageal real-time 3D echocardiography was performed in 50 patients undergoing undersized ring annuloplasty for IMR and in 21 patients with normal mitral valves. A customized image analysis protocol was used to assess 3D annular geometry and regional leaflet tethering. IMR recurrence (≥ grade 2) was assessed with two-dimensional transthoracic echocardiography 6 months after repair. Preoperative annular geometry was similar in all IMR patients, and preoperative leaflet tethering was significantly higher in patients with recurrent IMR (n=13) than in patients in whom IMR did not recur (n=37) (tethering index: 3.91 ± 1.01 vs 2.90 ± 1.17, p= 0.008; tethering angles of A3: 23.5° ± 8.9° vs 14.4° ± 11.4°, p= 0.012; P2: 44.4° ± 8.8° vs 28.2° ± 17.0°, p= 0.002; and P3: 35.2° ± 6.0° vs. 18.6° ± 12.7°, p < 0.001). Multivariate logistic regression analysis revealed the preoperative P3 tethering angle as an independent predictor of IMR recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84 to 1.00; p < 0.001). 3D echocardiography combined with valve modeling is predictive of recurrent IMR. Preoperative regional leaflet tethering of segment P3 is a strong independent predictor of IMR recurrence after undersized ring annuloplasty. In patients with a preoperative P3 tethering angle of 29.9° or larger, chordal-sparing valve replacement rather than valve repair should be strongly considered.

Surgical Treatment of Secondary Tricuspid Regurgitation: Insight Derived From Annulus Sizes and Tethering Distances

The main goal of this study was to explore the feasibility of stratifying patients with secondary tricuspid regurgitation (TR) into different risk levels, and to compare the surgical outcomes of patients within different risk levels who underwent different tricuspid valve repair (TVP) approaches. One hundred and one patients with left-sided valvular disease underwent either left-sided valvular replacement or repair, and 79 patients underwent concomitant TVP. Depending upon their tricuspid annulus diameter and tethering distances, the patients were assessed using 4 risk levels. The different surgical approaches were used in patients within different risk levels. Among the 101 patients, there were 32 patients within risk level I, 28 within risk level II, 20 within risk level III, 21 within risk level IV. In the first risk level, the patients with untreated tricuspid valves had no or mild TR after surgery. In the second and third risk levels, the patients treated with a modified De Vega procedure had mild TR at follow-up. In the fourth risk level, the patients treated with undersized annuloplasty rings exhibited an improved outcome. The evaluation of both tricuspid annular diameter and tethering distance may help clinicians to stratify patients with secondary TR into different risk levels as a means of choosing an optimal TVP approach. The application of a modified De Vega procedure or an undersized annuloplasty ring in patients within appropriate risk level could improve the treatment for secondary TR.

Saddle-Shaped Annuloplasty Improves Leaflet Coaptation in Repair for Ischemic Mitral Regurgitation

Current repair results for ischemic mitral regurgitation (IMR) with undersized annuloplasty rings are characterized by high IMR recurrence rates. Current annuloplasty rings treat annular dilatation, but they do little to improve (and may actually exacerbate) leaflet tethering. New saddle-shaped annuloplasty rings have been shown to maintain or restore a more physiologic annular and leaflet geometry and function. Using a porcine IMR model, we sought to demonstrate the influence of annuloplasty ring shape on leaflet coaptation. Eight weeks after posterolateral infarct, eight pigs with grade 2+ or higher IMR were randomized to undergo either a 28-mm flat ring annuloplasty (n = 4) or a 28-mm saddle-shaped ring annuloplasty (n = 4). Real-time three-dimensional echocardiography and a customized image analysis protocol allowed three-dimensional assessment of leaflet coaptation before and after annuloplasty. Total leaflet coaptation area was significantly higher after saddle-shaped ring annuloplasty (109.6 ± 26.9 mm(2)) compared with flat ring annuloplasty (46.2 ± 7.7 mm(2), p <0.01). After annuloplasty, total coaptation area decreased by 87.5 mm(2) (or 65%) in the flat annuloplasty group (p = 0.01), whereas total coaptation area increased by 22.2 mm(2) (or 25%) in the saddle-shaped annuloplasty group (p = 0.28). This study shows that the use of undersized saddle-shaped annuloplasty rings in mitral valve repair for IMR improves leaflet coaptation, whereas the use of undersized flat annuloplasty rings worsens leaflet coaptation. Because one of Carpentier's fundamental principles of mitral valve repair (durability) is to create a large surface of coaptation, saddle-shaped annuloplasty may increase repair durability.