Leaflet Tethering Research Articles

P4720Mitraclip XTR device used for the treatment of functional tricuspid regurgitation provides significant reduction of annular size

Abstract Background Tricuspid valve regurgitation (TR) is a progressive disease strongly associated with increased cardiac and all-cause mortality. The transcatheter approach to this pathology has been recently described with promising results in the treatment of symptomatic patients despite optimal medical therapy. Development of annular dilation and leaflet tethering represent a continuous pattern in the pathophysiology of functional TR; for this reason, to reduce and stabilize the annulus is the goal of an efficacious therapy. Purpose In order to simplify leaflet grasping, the novel MitraClip XTRdevice has significantly longer clip arms compared to its predecessor. The increased grasping length could be able to apply a radial tension on the tricuspid annulus, reducing it in dimensions. Despite, the increased tension on the leaflets may theoretically impose a higher risk for leaflet tearing We analyzed our single-center experience in order to clarify the capability of the device in the feature of annular reshapement. Methods Five high-risk patients (4 females, 72 (quartiles 69–79) y.o., EuroSCORE II 10 (7.25–11.2)% affected by severe symptomatic functional TR were treated with MitraClip XTR implantation in tricuspid position. Right ventricular function was apparently preserved in all cases and the mean sPAP was 41 (quartiles 38–45) mmHg. Perioperative echo-results were collected prospectively and analyzed. Results Procedural success (defined as a reduction of more than 1 degree of TR) was achieved in 4 cases (80%). 3±1 devices were implanted per patient in the antero-septal commissure. The tricuspid annular diameter (measured in four chamber view) was reduced from 39 (quartiles 39–41) mm to 31 (quartiles 30–31) mm (p=0.043). Accordingly, the effective regurgitant orifice area (EROA) decreased from 110 (quartiles 70 to 160) mm2 to 45 (quartiles 9–55) mm2 (p=0.02) and the systolic VTI in the hepatic veins decreased by 42%. No significant increase of trans-valvular mean gradients was observed (2.5 (quartiles 2.25 to 2.75)) mmHg vs 3.75 (quartiles 3,75 to 4) mmHg; p=0.2) as well no cases of acute leaflet tearing. Conclusion The reduction in tricuspid annulus size with the novel XTRdevice represents an unexpected and interesting achievement of the procedure. A significant reduction of annular dimensions might provide a more durable reduction of functional TR. Long-term follow-up data will be required to clarify these initial results and as well as patient selection criteria.

P3804Left ventricular wall thickness measured with computed tomography predicts mitral regurgitation improvement in patients implanted with cardiac resynchronization therapy

Abstract Background Secondary mitral regurgitation (MR) is common in heart failure (HF) patients and results in progressive left ventricular (LV) dilatation, papillary muscle (PM) displacement and mitral valve leaflet tethering. In selected HF patients, cardiac resynchronization therapy (CRT) has been proved to reduce MR by LV reverse remodeling, resynchronization of PM insertion site contraction and reduction in MV tenting area and inter PM distance. However, data regarding the impact of LV wall thickness (WT) on MR improvement are scarce. Methods In this prospective study, a total 54 patients scheduled for CRT, underwent pre procedural CT. Reduced LV WT was defined as WT<6mm and was quantified as a percentage of total LV area. LV was segmented in 17 segments to assess the number of LV segments with reduced WT. End point was 6-month echocardiographic MR improvement by ≥1 class. For this analysis, we focused on patient with mild (class 2) to severe (class 4) MR. Results Among the 54 patients, 38 (70.4%) had mild to severe MR at baseline and a total of 16 (42.1%) experienced MR improvement by ≥1 class at 6 months. there was no difference regarding the co-morbidities, electrocardiogram and echocardiographic parameters between patients with or without MR improvement. However, patients without MR improvement had significant higher NT-pro BNP level at baseline. Interestingly, patients without MR improvement had larger LVWT <6mm area (41.541.5±19.4 vs. 22.4±16.1%, p=0.003) associated with higher number of papillary muscle (PM) inserted in reduced LV WT area. In multivariate analysis, an area ≥25% of LVWT<6mm including at least 1 PM insertion was the only predictor of no MR improvement at 6 months (HR 18.4 (1.25–271.75), p=0.034). Lastly, patients with MR improvement had significant lower rate of basal segments with reduced WT, especially in the lateral location. Of note, patients with MR improvement exhibited fewer rate of postero-lateral WT <6mm segments. Left ventriculat segmentation Conclusion LV WT evaluated using CT is a strong predictor of no MR improvement in HF patients with mild to severe MR and who scheduled for CRT implantation.

Echocardiographic assessment of mitral regurgitation

Mitral regurgitation (MR) is one of the most frequent indications for valve surgery in developed countries, and echocardiographic assessment is an essential tool to evaluate its etiologies, severity, and therapeutic indications. The mitral valve apparatus is a complex structure composed of several parts: apart from the mitral valve leaflets and annulus, it also includes the chordae tendineae, papillary muscles, and left ventricular (LV) wall. MR can be caused not only by organic changes of the mitral valve leaflets or chordae (primary MR) but also by extreme mitral annular enlargement or mitral leaflet tethering due to displacement and malfunction of papillary muscles and LV wall (secondary MR). In secondary MR with LV dysfunction, a milder degree of MR can be associated with adverse outcomes compared with primary MR. Grading the severity is the first step in evaluation of indication for surgical/transcatheter interventions. As such, there are several techniques to assess the severity of MR using echocardiography. However, none of the techniques is reliable enough by itself, and it is always recommended to integrate multiple methods. In cases where echocardiographic assessment of MR severity is inconclusive, magnetic resonance may be helpful. In addition to the severity, anatomical information, such as localization in primary MR due to mitral valve prolapse and LV size in secondary MR due to LV dilatation/dysfunction, is an important concern in presurgical echocardiography. Transesophageal echocardiography and three-dimensional echocardiography are key techniques for anatomical evaluation including mitral valve and LV volumes. In transcatheter intervention for MR, echocardiography plays a pivotal role as a guide for procedures and endpoints. In this review article, the authors provide a comprehensive summary of current standards of echocardiographic assessment of MR.

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.

Standardized Subannular Repair Improves Outcomes in Type IIIb Functional Mitral Regurgitation

The major drawback of isolated annuloplasty in secondary mitral regurgitation (MR) is the reoccurrence of MR. We prospectively compared the results of isolated annuloplasty vs annuloplasty with simultaneous standardized subannular repair. The study comprised 101 patients with secondary type IIIb MR. Of these, 51 underwent annuloplasty plus standardized subannular repair with realignment of both papillary muscles (subannular repair) and 50 underwent isolated annuloplasty. The primary study end point was the reoccurrence of MR >2 at the 1-year follow-up. Secondary end points were survival, freedom from major adverse cardiac events, and residual leaflet tethering. Baseline characteristics were comparable in both groups. There was no significant difference in in-hospital mortality (P= .3). Although postrepair MR was comparable between the subannular repair and isolated annuloplasty subgroups, the residual leaflet tethering (tenting area, 127.6 ± 35.8 mm2 vs 166.3 ± 47.3 mm2, P= .02; posterior mitral leaflet angle, 19.2 ± 4.7 degrees vs 24.8 ± 5.2 degrees, P= .001; anterior mitral leaflet angle, 25.4 ± 5.8 degrees vs 34.1 ± 4.0 degrees, P= .001; and tenting height, 5.9 ± 1.4 mm vs 9.2 ± 2.2 mm, P= .001) were significantly increased in the isolated annuloplasty group (P < .001). At the 1-year follow-up, we found a significant difference between the groups in the freedom from MR >2 of 98% (50 of 51) for subannular repair vs 86.7% (39 of 45) for isolated annuloplasty (P= .045) and mortality of 0% (0 of 51) for subannular repair vs 10% (5 of 50) for isolated annuloplasty (P= .025). In secondary MR with reduced leaflet motion, the combination of annuloplasty and standardized subannular repair is associated with a significantly reduced MR reoccurrence, decreased residual leaflet tenting, and significantly improved 1-year outcome compared with annuloplasty alone.

Mitral annuloplasty for atrial functional mitral regurgitation in patients with chronic atrial fibrillation.

Surgical ring annuloplasty is generally performed in patients with symptomatic atrial functional mitral regurgitation (MR) caused by long-standing atrial fibrillation (AF). However, its clinical results have not been well reported. Twenty consecutive patients with atrial functional MR (mean age of 68 ± 9 years) and a left ventricular (LV) ejection fraction (EF) greater than 50% underwent mitral annuloplasty. Concomitant procedures included tricuspid valve surgery in 16 patients, AF ablation in 13 patients, and coronary artery bypass grafting in 2 patients. We reviewed the clinical outcomes of those patients and investigated the specific preoperative echocardiographic findings related to MR recurrence. At discharge, the mean left atrial (LA) volume index and mean tricuspid regurgitation peak gradient had significantly decreased from 94 ± 59 mL/m 2 to 58 ± 30 mL/m 2 and from 34 ± 11mm Hg to 23 ± 5mm Hg, respectively. During the follow-up period of 28 ± 17 months, the New York Heart Association functional class significantly improved from 2.3 ± 0.6 to 1.3 ± 0.6. Four patients developed recurrent MR, and of those, two required reoperation. Those with recurrent MR had a significantly larger preoperative LV dimension than those without recurrent MR. Preoperative three-dimensional transesophageal echocardiography was performed in 12 patients, revealing a greater degree of leaflet tethering in patients with recurrent MR than that in patients without recurrent MR. In patients with the combination of atrial functional MR, left ventricular dilatation and excessive leaflet tethering, mitral annuloplasty alone may not be sufficient to achieve long-term correction of MR.

On the simulation of mitral valve function in health, disease, and treatment.

The mitral valve (MV) is the heart valve that regulates blood ?ow between the left atrium and left ventricle (LV). In situations where the MV fails to fully cover the left atrioventricular ori?ce during systole, the resulting regurgitation causes pulmonary congestion, leading to heart failure and/or stroke. The causes of MV insuf?ciency can be either primary (e.g. myxomatous degeneration) where the valvular tissue is organically diseased, or secondary (typically inducded by ischemic cardiomyopathy) termed ischemic mitral regurgitation (IMR), is brought on by adverse LV remodeling. IMR is present in up to 40% of patients and more than doubles the probability of cardiovascular morbidity after 3.5 years. There is now agreement that adjunctive procedures are required to treat IMR caused by lea?et tethering. However, there is no consensus regarding the best procedure. Multicenter registries and randomized trials would be necessary to prove which procedure is superior. Given the number of proposed procedures and the complexity and duration of such studies, it is highly unlikely that IMR procedure optimization will be achieved by prospective clinical trials. There is thus an urgent need for cell and tissue physiologically based quantitative assessments of MV function to better design surgical solutions and associated therapies. Novel computational approaches directed towards optimized surgical repair procedures can substantially reduce the need for such trial-and-error approaches. We present the details of our MV modeling techniques, with an emphasis on what is known and investigated at various length scales.

Echocardiographic Predictors of Tricuspid Ring Annuloplasty Repair Failure for Functional Tricuspid Regurgitation

Significant tricuspid regurgitation (TR) recurs after tricuspid valve repair of functional TR in 15% to 20% within the first year, and 30% to 70% within 5 years. Prior investigations report leaflet tethering, and not tricuspid valve annular diameter (TVAD), as predictive of recurrent TR. The authors hypothesize that pre-repair TVAD is predictive of repair failure for functional TR. Fifty-four patients with functional TR scheduled for left heart surgery and tricuspid valve repair with ring annuloplasty. Retrospective study design. Pre- and post-repair transthoracic and intraoperative transesophageal echocardiographic data included left and right ventricular functions, tricuspid leaflet tethering height, TVAD, and TR severity. Successful repair was defined as ≤2+ TR. Tertiary care medical center. None. Forty-five patients had a successful repair and 9 did not. Preoperative and intraoperative TVAD in diastole (TVADdiast) ≥4.2 cm, and preoperative systole (TVADsyst) ≥3.7 cm, but not leaflet tethering, were predictive of repair failure. Right ventricular (RV) width >4.88 cm was associated with repair failure. Neither pre- nor post-repair pulmonary artery systolic pressures (PASP) were predictors of repair failure. However, PASP did not change nor did RV function improve in the nonsuccessful repair group. For patients with functional TR undergoing primary left heart surgery, preoperative TVAD (systole and diastole), RV width, and postoperative RV function were predictors of repair outcome. Earlier TV repair and optimizing right heart function may improve repair outcome.

Minimally invasive mitral valve repair for functional mitral regurgitation.

Summary Systolic heart failure is frequently accompanied by a relevant functional mitral valve regurgitation (FMR) which develops as a direct sequela of the ongoing left ventricular remodelling. The severity of mitral regurgitation is further aggravated by progressive left ventricular enlargement causing leaflet tethering and reduced systolic leaflet movement. The prognosis of such patients is obviously limited by an underlying left ventricular disease, and the correction of secondary FMR has been previously suggested as predominantly ‘cosmetic’ surgery in the setting of ongoing cardiomyopathy. Inferior results of an isolated annuloplasty in type IIIb FMR supported the philosophy of malignant course of progressive cardiomyopathy and resulted in increasingly restricted indications for mitral valve surgery for FMR in the guidelines. The lack of a standardized pathophysiological approach to correct type IIIb FMR led to the development of valve replacement strategy and edge-to-edge catheter-based mitral valve procedures, which became the most frequent procedures in the FMR setting in Europe. Modern mitral valve surgery combines the advantages of 3-dimensional endoscopic minimally invasive surgical approach with standardized subannular repair to address the pathophysiological background of type IIIb FMR. The perioperative results have been significantly improved, and there is a growing evidence of improved long-term stability of subannular repair procedures as compared to isolated annuloplasty. This review article aims to present the current state-of-the-art of the modern mitral valve surgery in FMR and provides suggestions for future trials analysing the potential advantages in these patients.

Indirect Annuloplasty to Treat Functional Mitral Regurgitation: Current Results and Future Perspectives.

The incidence of mitral regurgitation (MR) is approximately 1.7% in the developed world, and this increases to more than 10% in patients aged over 75 years. Functional (or secondary) mitral regurgitation (FMR) is defined as poor leaflet coaptation and tethering secondary to either ischemic or non-ischemic left ventricular (LV) dysfunction and dilatation. FMR is more common than degenerative (or primary) MR and is associated with significantly worse outcomes in patients with heart failure, post myocardial infarction and following coronary artery bypass graft surgery. Patients with severe degenerative MR have excellent outcomes with surgical repair, however the benefits of surgery in FMR are less clear. Although annuloplasty is associated with a lower operative mortality compared to replacement, the recurrence rate of mitral regurgitation is high in patients with FMR and neither surgical repair or replacement have been shown to reduce hospitalisation or death in FMR. Furthermore, nearly half of patients are deemed too high risk for surgery and therefore most patients are managed conservatively and there remains an unmet clinical need. Transcatheter mitral valve interventions are an emerging alternative for those at high surgical risk. This mini review focuses on indirect mitral annuloplasty: anatomical considerations, patient selection, current devices, implantation techniques and the associated clinical outcome data.

Utilization of intra-aortic balloon pump to allow MitraClip procedure in patients with non-coapting mitral valve leaflets: a case series.

BackgroundThe MitraClip (MC) procedure was designed for high-risk surgical patients with severe mitral regurgitation (MR). Some patients do not meet the required anatomical criteria due to advanced left ventricular remodelling and mitral annular dilatation leading to leaflet tethering and insufficient coaptation surface. Theoretically, ‘temporary remodelling’ of the mitral valve apparatus by pharmacological and/or mechanical support using intra-aortic balloon pump (IABP) could improve leaflets coaptation.Case summaryWe report a case series of four patients with severe MR and non-coapting leaflets who underwent MC implantation. Sufficient coaptation was achieved only after insertion of IABP. The first patient presented with worsening heart failure and severe MR after a non-reperfused posterior wall myocardial infarction (MI), underwent a successful procedure with good results. The second patient presented with worsening heart failure secondary to rheumatic MR, and underwent MC procedure with good results after the insertion of IABP. The third patient developed worsening heart failure and severe MR 2 months after an acute inferior-lateral MI, and underwent a successful procedure. The fourth patient presented with respiratory failure, the patient underwent the procedure, but unfortunately died a few days following the procedure from multiorgan failure. In each case, the insertion of the IABP decreased annular mitral diameter and increased the coaptation surface as assessed by transoesophageal echocardiography.DiscussionFor patients suffering from symptomatic severe MR who are not suitable candidates for MC procedure, IABP system enabled us to overcome mitral leaflet gap and complete the MC procedure successfully.

Contrasting Effects of Pharmacological, Procedural, and Surgical Interventions on Proportionate and Disproportionate Functional Mitral Regurgitation in Chronic Heart Failure.

Two distinct pathways can lead to functional mitral regurgitation (MR) in patients with chronic heart failure and a reduced ejection fraction. When remodeling and enlargement of the left ventricle (LV) cause annular dilatation and tethering of the mitral valve leaflets, there is a linear relationship between LV end-diastolic volume and the effective regurgitant orifice area of the mitral valve. These patients, designated as having proportionate MR, respond favorably to treatments that lead to reversal of LV remodeling and a decrease in LV volumes (eg, neurohormonal antagonists and LV assist devices), but they may not benefit from interventions that are directed only at the mitral valve leaflets (eg, transcatheter mitral valve repair). In contrast, when ventricular dyssynchrony causes functional MR attributable to unequal contraction of the papillary muscles, the magnitude of regurgitation is greater than that predicted by LV volumes. These patients, designated as having severe but disproportionate MR, respond favorably to treatments that are directed to the mitral valve leaflets or their supporting structures (eg, cardiac resynchronization or transcatheter mitral valve repair), but they may derive little benefit from interventions that act only to reduce LV cavity size (eg, pharmacological treatments). This novel conceptual framework reflects the important interplay between LV geometry and mitral valve function in determining the clinical presentation of patients, and it allows characterization of the determinants of functional MR to guide the most appropriate therapy in the clinical setting.

Early Clinical Results of The Clover Technique for Severe Functional Tricuspid Regurgitation Associated with Leaflet Tethering

Early Clinical Results of The Clover Technique for Severe Functional Tricuspid Regurgitation Associated with Leaflet Tethering

75-Year-Old Man With Chest Pain and Dyspnea

75-Year-Old Man With Chest Pain and Dyspnea

One-Year Outcomes After MitraClip for Functional Mitral Regurgitation.

Secondary mitral regurgitation (SMR) occurs in the absence of organic mitral valve disease and may develop as the left ventricle dilates or remodels or as a result of leaflet tethering with impaired coaptation, most commonly from apical and lateral distraction of the subvalvular apparatus, with late annular dilatation. The optimal therapy for SMR is unclear. This study sought to evaluate the 1-year adjudicated outcomes of all patients with SMR undergoing the MitraClip procedure in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) Investigational Device Exemption program, which is comprised of the randomized clinical trial, the prospective High-Risk Registry, and the REALISM Continued Access Registry (Multicenter Study of the MitraClip System). Patients with 3+/4+ SMR enrolled in EVEREST II were stratified by non-high surgical risk (non-HR) and high surgical risk (HR) status (defined as Society of Thoracic Surgeons risk of mortality ≥12% or predefined risk factors). Clinical, echocardiographic, and functional outcomes at 1 year were evaluated. A total of 616 patients (482 HR, 134 non-HR; mean age, 73.3±10.5 years; Society of Thoracic Surgeons risk, 10.2±6.9%) with SMR underwent the MitraClip procedure. At baseline, 80.5% of patients were in New York Heart Association class III/IV. Major adverse events at 30 days included death (3.6%), stroke (2.3%), and renal failure (1.5%). At discharge, 88.8% had MR ≤2+. At 1 year, there were 139 deaths, and the Kaplan-Meier estimate of freedom from mortality was 76.8%. The majority of surviving patients (84.7%) remained with MR ≤2+ and New York Heart Association class I/II (83.0%). Kaplan-Meier survival at 1 year was 74.1% in HR patients and 86.4% in non-HR patients ( P=0.0175). At 1 year, both groups achieved comparable MR reduction (MR ≤2+, 84.0% versus 87.0%) and improvement in left ventricular end-diastolic volume (-8.0 mL versus -12.7 mL), whereas New York Heart Association class I/II was found in 80.1% versus 91.8% ( P=0.008) of HR and non-HR patients, respectively. In HR patients, the annualized rate of heart failure hospitalizations decreased from 0.68 to 0.46 in the 12 months before to 12 months after the procedure ( P<0.0001). Transcatheter mitral valve repair with the MitraClip in patients with secondary MR is associated with acceptable safety, reduction of MR severity, symptom improvement, and positive ventricular remodeling. https://www.clinicaltrials.gov . Unique identifiers: NCT00209274, NCT01940120, and NCT01931956.

Left Ventricular Pseudoaneurysmectomy and Mitral Valve Replacement 30 Years after Blunt Polytrauma

Left ventricular (LV) pseudoaneurysms are the consequence of cardiac rupture, usually contained by adherent pericardium or fibrous scar tissue. They represent, from a functional point of view, the acquired blood-filled spaces that are external to the cardiac chambers but communicating with the ventricle. They can occur after transmural myocardial infarction or, albeit less frequently, post-traumatically. This cardiac disease has been a topic of discussion since the pioneering days of heart surgery. We present a case of a posttraumatic LV pseudoaneurysm, in which the causative blunt trauma happened 30 years prior to the onset of symptoms. Severe functional mitral regurgitation (FMR) resulted from leaflet tethering and partial rupture of the posteromedial papillary muscle complex.

Abstract 16759: Repair of Functional Mitral Regurgitation Restores Life Expectancy in Selected Patients Less Than 70 Years of Age

Introduction: Functional mitral regurgitation (MR) is common and associated with significant morbidity and mortality. Notably, correction of functional MR has not been demonstrated to improve survival. We therefore evaluated outcomes following repair of functional MR utilizing prospective population data. Hypothesis: We hypothesized that correction of functional MR may be associated with a survival benefit in selected patients. Methods: Between 2001 and 2018, 1896 patients underwent complex mitral surgery at our institution, of which 168 underwent repair of functional MR in whom the etiology of MR was due to annular dilation in 37, leaflet tethering in 100 and mixed in 31. Mean patient age was 66.2±9.9 years and 66 (39%) were female. Concomitant coronary artery bypass grafting was performed in 79 (47%) with an average of 2.5 grafts per patient. The mean preoperative left ventricle (LV) ejection fraction was 38.3±11.4% and indexed LV end-systolic dimension, 25.1±5.4 mm/m 2 . Average clinical and echocardiographic follow up averaged 5.5±3.8 years. Results: Thirty-day mortality was 0.6%. Overall survival for the patients following repair of functional MR was 93.3±2.0% and 75.6±3.8% 1-, and 5-years after surgery. Not surprisingly, sensitivity analysis demonstrated that survival was influenced by age at operation (hazard ratio (HR) 1.05±0.02 per increasing year) and preoperative left ventricle (LV) class (HR 1.32±0.18 per increasing LV grade) (Both p&lt;0.05). For patients &lt;70 years of age and with a preoperative LVEF &gt;35%, 5- year survival was 92.3±7.4%, respectively. This compares to an expected 5- year survival of 99.1%, for age and gender matched Canadians (Figure). For patients &lt;70 and with a preoperative LVEF &gt;35%, 5-year freedom from recurrent MR ≥2+ was 81.3±9.8%. Conclusions: Repair of functional MR is associated with favorable early and intermediate term results in selected patients. Notably, for the subset of functional MR patients &lt;70 and with a LVEF&gt;35%, 5-year survival was comparable to age and gender matched patients from the general population.

Functional Tricuspid Regurgitation in Mitral Valve Disease.

Functional tricuspid regurgitation is a common finding in patients with left-sided heart disease. If left untreated, it may reduce survival, limit functional capacity and cause end-organ dysfunction. Annulus dilation and leaflet tethering due to right ventricle remodeling are 2 major pathophysiologic mechanisms in functional tricuspid regurgitation. Even if surgical treatment remains the gold standard, indication and timing of surgical interventions remain the object of debate in the medical community. More recently, numerous transcatheter therapies have been developed in order to offer less invasive options to patients who otherwise would have a high risk of mortality and morbidity with surgical interventions.

Characterization of 3-dimensional papillary muscle displacement in in vivo ovine models of ischemic/functional mitral regurgitation

ObjectivePapillary muscle (PM) displacement contributes to ischemic/functional mitral regurgitation (IMR/FMR). The displaced PMs pull the mitral leaflets into the left ventricle (ie, toward the apex) thus hampering leaflet coaptation. Intuitively apical leaflet tethering results from apical PM displacement. The 3-dimensional directions of PM displacement are, however, incompletely characterized. MethodsData from in vivo ovine models of IMR (6-8 weeks of posterolateral infarction, n = 12) and FMR (9-21 days of rapid left ventricular pacing, n = 11) were analyzed. All sheep had radiopaque markers implanted on the anterior and posterior PM (PPM) tips, around the mitral annulus, and on the left ventricular apex. To explore 3-dimensional PM displacement directions, differences in marker coordinates were calculated at end-systole before and during IMR/FMR using a right-handed coordinate system centered on the mitral annular “saddle horn” with the y-axis passing through the apical marker. ResultsNo apical PM displacement was observed during either IMR or FMR. The anterior PM displaced laterally during FMR. Posterolateral PPM displacement was observed during IMR and FMR. ConclusionsExperimental in vivo ovine models suggest posterolateral PPM displacement as a predominant pathomechanism leading to apical leaflet tethering during IMR/FMR.

New Device for the Treatment of Functional Ischemic Mitral Regurgitation: Proof of Concept in an In Vitro Model.

Optimal surgical treatment of functional ischemic mitral regurgitation (FIMR) is still controversy. Due to the underlying pathophysiology, stand-alone ring annuloplasty is assumed with a high recurrence rate of mitral regurgitation, thus additional subvalvular repair techniques might improve the results. This in vitro study introduces a new device for subvalvular mitral valve repair. We developed a new device for subvalvular mitral valve repair, consisting of two frames for papillary muscle (PM) attachment, which are connected with two holding bars serving for fixation of the device on an annuloplasty ring. In the first experimental run, porcine mitral valves including the chordae tendineae and PMs were fixated on a holding device, consisting of a holding ring simulating mitral annulus dilation and height-adjustable frames for PM attachment simulating leaflet tethering. In vitro regurgitant volume was determined in a pulse duplicator. Afterward, the frames for PM attachment were replaced by our newly developed device and the measurements were repeated. In the model simulating FIMR, the regurgitant volume was 44.3 ± 12.38 mL/stroke. After subvalvular reconstruction with our new device, the regurgitant volume was significantly reduced to 33.1 ± 11.68 mL/stroke (p = 0.009). In this specific in vitro model, our new device for subvalvular mitral valve reconstruction led to a significant reduction of the regurgitant volume, thus representing a promising technique to potentially improve the results of mitral reconstruction in ischemic functional mitral valve regurgitation. Additional studies are required to further investigate and improve our device.