Chronic Ischemic Mitral Regurgitation Research Articles

Tailored repair of the subvalvular apparatus using 'cut and transfer' technique in patients with chronic ischaemic mitral regurgitation and severe tethering of the mitral leaflets

Tethering of both mitral leaflets is the predominant mechanism of mitral regurgitation in patients with chronic ischaemic cardiomyopathy. For patients with severe mitral leaflet tethering, we have developed a surgical approach alternative to the conventional undersized annuloplasty ring that targets the subvalvular apparatus and aims to reconstitute the leaflet coaptation by reducing leaflet tethering in three steps, including the translocation of secondary chordae of the anterior leaflet in primary position, the relocation of the posterior papillary muscle closer to the mitral annulus and the plication of the lateral wall of the left ventricle when a large infarcted area was present. All repairs were completed by a 'true-sized' annuloplasty ring. In this paper, we present the indications, the technical aspects and the initial results of this tailored approach in 53 patients with moderate to severe chronic ischaemic mitral regurgitation and severe leaflet tethering.

Quantitative Evaluation of Annuloplasty on Mitral Valve Chordae Tendineae Forces to Supplement Surgical Planning Model Development

Computational models of the heart's mitral valve (MV) exhibit potential for preoperative surgical planning in ischemic mitral regurgitation (IMR). However challenges exist in defining boundary conditions to accurately model the function and response of the chordae tendineae to both IMR and surgical annuloplasty repair. Towards this goal, a ground-truth data set was generated by quantifying the isolated effects of IMR and mitral annuloplasty on leaflet coaptation, regurgitation, and tethering forces of the anterior strut and posterior intermediary chordae tendineae. MVs were excised from ovine hearts (N=15) and mounted in a pulsatile heart simulator which has been demonstrated to mimic the systolic MV geometry and coaptation of healthy and chronic IMR sheep. Strut and intermediary chordae from both MV leaflets (N=4) were instrumented with force transducers. Tested conditions included a healthy control, IMR, oversized annuloplasty, true-sized annuloplasty, and undersized mitral annuloplasty. A2-P2 leaflet coaptation length, regurgitation, and chordal tethering were quantified and statistically compared across experimental conditions. IMR was successfully simulated with significant increases in MR, tethering forces for each of the chordae, and decrease in leaflet coaptation (p<.05). Compared to the IMR condition, increasing levels of downsized annuloplasty significantly reduced regurgitation, increased coaptation, reduced posteromedial papillary muscle strut chordal forces, and reduced intermediary chordal forces from the anterolateral papillary muscle (p<.05). These results provide for the first time a novel comprehensive data set for refining the ability of computational MV models to simulate IMR and varying sizes of complete rigid ring annuloplasty.

Mitral valve stenosis and left ventricular hemodynamic alterations after mitral valve repair

Background Mitral valve repair (MVR) shows clinical and economic superiority over mitral valve replacement in patients with dystrophic and rheumatic regurgitation, but outcomes are less certain in chronic ischemic mitral regurgitation (IMR). We hypothesize that MVR may have adverse effects on LV hemodynamics resulting from suboptimal annuloplasty geometry and post-repair mitral valve stenosis whose consequences are most acutely felt in IMR patients because of their impaired LV function. To test this hypothesis, we qualitatively described post-repair hemodynamics and measured LV inflow quantities (peak diastolic inflow velocity, transmitral pressure, and inflow angle) after MVR in sheep. Methods

Chronic ischemic mitral regurgitation – adiagnostic and therapeutic challenge

Chronic ischemic mitral regurgitation (IMR) is a valvular disorder caused by left ventricular dysfunction due to chronic coronary artery disease. It represents a valvular consequence of left ventricular contractile dysfunction and/or pathologic remodeling that indirectly impairs appropriate closing of the mitral valve. IMR is not caused by a structural change of the mitral valve. Acute postinfarction mitral regurgitation is also differentiated from chronic IMR. Chronic IMR occurs in the chronic stage of myocardial infarction in 20–50 % of the patients; its prevalence in the population is increasing. In patients after myocardial infarction, impaired contractility and mitral regurgitation are the most important negative prognostic factors. Furthermore, regurgitation that would be considered mild in patients with organic mitral valve disease already has a negative prognostic implication in patients with IMR. Echocardiogram is the fundamental tool for diagnostic evaluation and treatment planning in patients with IMR. The key parameters that have to be assessed include left ventricular contractile dysfunction, degree of left ventricular remodeling, pathologic changes in mitral valve geometry and quantification of regurgitation severity. In some patients, significant IMR can only be identified by stress echocardiography. Although IMR has an important negative impact on prognosis, indications for treatment and best treatment options have still not been well defined. According to the European and American guidelines, significant IMR should be treated, particularly in patients who are candidates for surgical coronary artery revascularisation. However, there is still no conclusive evidence that any surgical or percutaneous treatment of IMR improves patients’ prognosis.

Postinfarct Intracardiac Mass with Severe Mitral Regurgitation: Late Rupture of One of the Heads of Posteriomedial Papillary Muscle

ABSTRACT Acute ischemic mitral regurgitation is due to complete or partial rupture of either anterolateral or posteriomedial papillary muscles occurring within a week of acute myocardial infarction. Chronic ischemic mitral regurgitation is due to postinfarct remodeling leading to imbalance between tethering and closing forces of mitral valve apparatus. We present a 64-year-old male, presenting with acute pulmonary edema secondary to severe mitral regurgitation, a week after his myocardial infarction. Transthoracic echocardiogram detected a mobile intracardiac mass near anterior mitral leaflet with no clear-cut intracardiac origin of this mass. Perioperative transesophageal echocardiography detected rupture of one of the heads of posteriomedial papillary muscle. This case illustrates a rare presentation of postinfarct rupture of one of the heads of posteriomedial papillary muscle occurring late after infarction presenting as an intracardiac mass, which can have surgical implications. How to cite this article Panduranga P. Postinfarct Intracardiac Mass with Severe Mitral Regurgitation: Late Rupture of One of the Heads of Posteriomedial Papillary Muscle. J Perioper Echocardiogr 2014;2(1)29-31.

Surgical management of moderate ischemic mitral valve regurgitation: Where do we stand?

Ischemic mitral regurgitation (IMR) represents a common complication after myocardial infarction. The valve is anatomically normal and the incompetence is the result of papillary muscles displacement and annular dilatation, causing leaflets tethering. Functionally the leaflets present a restricted systolic motion due to tethering forces that displaces the coaptation surface toward the left ventricle apex. The patients present poor left ventricular function at the time of surgery and the severity of the mitral regurgitation increases the risk of mortality. Currently there is general agreement to treat surgically severe IMR nevertheless strong evidences for patient with moderate insufficiency remains poor and proper treatment debated. The most effective surgical approach for the treatment of IMR remains debated. Some authors demonstrated that coronary artery bypass graft (CABG) alone is beneficial in patients with IMR. Conversely, in most patients, moderate IMR will persist or worsen after CABG alone which translate in higher long-term mortality as a function of residual mitral regurgitation severity. A probable reason for this unclear surgical management of functional MR is due to the contemporary suboptimal results of reparative techniques. The standard surgical treatment of chronic IMR is CABG associated with undersized annuloplasty using complete ring. Though, the recurrence of mitral regurgitation remains high (> 30%) because of continous left ventricle remodeling. To get better long term results, in the last decade, several subvalvular procedures in adjunct to mitral anuloplasty have been developed. Among them, surgical papillary muscle relocation represents the most appreciated option capable to restore normal left ventricle geometry. In the next future new preoperative predictors of increased mitral regurgitation recurrence are certainly needed to find an individual time period of treatment in each patient with moderate IMR.

Ring annuloplasty for ischemic mitral regurgitation: a single center experience.

Ischemic mitral regurgitation associated with coronary artery disease presents a management challenge to cardiac surgeons. We report our early and midterm results of chronic ischemic mitral regurgitation treated with concomitant mitral ring annuloplasty and coronary artery bypass grafting. We performed a retrospective review of the medical records of patients who underwent coronary artery bypass grafting at our institute from January 2009 to December 2011. Data were collected in 50 patients with chronic ischemic mitral regurgitation who had mitral ring annuloplasty along with coronary artery bypass grafting. Preoperative data, echocardiographic findings, operative procedure, outcome, and perioperative hemodynamics were analyzed. Early and intermediate follow-up data were also collected and analyzed. There were 3 (6%) early and 9 (18%) late deaths. Of the survivors, 38 (76%) had a significant reduction in left ventricular end-diastolic and end-systolic dimensions and improvement in New York Heart Association functional class. Despite a risk of residual regurgitation, mitral ring annuloplasty combined with coronary artery bypass appears to be a good treatment option in selected patients with chronic ischemic mitral regurgitation.

Circulation Editors’ Picks

<i>Circulation</i> Editors’ Picks

Cut-and-Transfer Technique for Ischemic Mitral Regurgitation and Severe Tethering of Mitral Leaflets

Chronic ischemic mitral regurgitation (MR) denotes abnormal function of normal leaflets resulting from left ventricular enlargement. We present the midterm results of a tailored mitral repair technique using a combination of the following subvalvular procedures: (1) detachment and reimplantation of secondary chordae on the free edge of the anterior leaflet ("cut-and-transfer" technique), (2) relocation of the posterior papillary muscle (PPM) closer to the mitral annulus, and (3) infarct plication on the lateral wall of the left ventricle. From 2008 to 2011, 49 patients with moderate to severe ischemic MR underwent coronary surgery plus mitral valve repair using the cut-and-transfer and PPM relocation techniques. All the patients received a "true-sized" semirigid complete annuloplasty ring. In 20 patients, a plication of the lateral wall of the left ventricle was performed to reduce the tethering of the mitral leaflets. The mean number of coronary grafts per patient was 3.4 ± 0.4. Hospital mortality was 2%. No patient died during 1-year follow-up and New York Heart Association (NYHA) class improved from 3.4 ± 0.5 to 1.4 ± 0.6 (p < 0.0001). The 1-year echocardiogram showed the following changes from baseline: mitral regurgitation grade (0-4) 2.9 ± 0.4 versus 0.2 ± 0.4 (p < 0.0001), left ventricular end-systolic volume index (mL/m(2)) 52.7 ± 13.1 versus 48.2 ± 10.1 (p = 0.07), left ventricular end-systolic index (mL/m(2)) 92.9 ± 16.5 versus 83.4 ± 15.9 (p <0.005), and ejection fraction (%) 37.8 ± 6.3 versus 44.2 ± 8.1 (p < 0.0001). Both clinical and echocardiographic results show that reducing the tethering of the mitral leaflets with tailored interventions on subvalvular apparatus without undersizing the mitral annulus can safely and effectively correct chronic ischemic MR.

Surgical approximation of the posterior papillary muscle in chronic ischemic mitral regurgitation – presentation of a new method of mitral valve repair

Background The optimal surgical management of the chronic ischemic mitral regurgitation remains controversial and the negative effect of the displacement of the papillary muscles is evident. To emerge this effect we performed a new method to approximate the papillary muscles as adjunct procedure to ring annuloplasty. The purpose of this study was to evaluate the early outcome and the effect of this method.

Impact of correction of ischemic mitral valve on left ventricular reverse remodeling

Background Chronic ischemic mitral regurgitation (IMR) is frequent complication of myocardial infarction. It is associated with high cardiovascular morbidity and mortality. We examined the effects of surgery of ischemic mitral valve on reverse remodeling of left ventricle, impact on functional state of patients after operation, assessment of early morbidity and mortality. Methods

Echocardiographic Determinants of Ischemic Mitral Regurgitation

It is not clear whether the presence and degree of chronic ischemic mitral regurgitation (IMR) in patients with left ventricular (LV) dysfunction are related to LV dysfunction, local LV remodeling or mitral valve deformation. We sought to establish the strongest determinants of IMR severity in patients with LV dysfunction and IMR. We prospectively performed transthoracic echocardiography for 135 patients (mean age = 60.76 ± 9.69 years, 71.9% male) with LV dysfunction (ejection fraction ≤ 50%) and coronary artery disease (70% stenosis in ≥ 1 coronary artery and no myocardial infarction during the previous 16 days). Global and local LV remodeling and mitral deformity indices were measured. Using the vena contracta, MR severity was graded as no regurgitation; mild; moderate; and severe. Mild regurgitation was found in 45 (33.3%) patients, moderate in 71 (52.6%), severe in 6 (4.4%), and no regurgitation in 13 (9.6%). By linear logistic multivariable analysis, the major echocardiographic determinants of MR severity were tenting area (TA), sphericity index (LV systolic length/width), and C-septal (distance between the leaflet coaptation and the septum). TA was best related to coaptation depth and annulus diameter. Mitral annular diameter was best correlated with left atrial surface area (r = 0.630, p < 0.001). TA was significantly correlated with annulus diameter and, along with sphericity index and C-septal, were the independent echocardiographic determinants of MR severity. These findings warrant consideration when performing mitral valve repairs for patients with IMR.

A good surgical option for ischemic mitral regurgitation in co-morbid patients: semicircular reduction annuloplasty.

BackgroundRing annuloplasty is the standard treatment of ischemic mitral regurgitation (MR), however, it has been associated with some drawbacks. It abolishes normal annular dynamics and freezes the posterior leaflet. In the present study, we evaluated Paneth suture annuloplasty in chronic ischemic MR and both early and mid-term outcomes of the technique on a selected population.MethodsThe study period was from June 2010 to June 2012. We operated on 21 patients who had the diagnosis of coronary artery disease and MR of grade 3 or 4. The patients had both a coronary artery bypass operation and the mitral semicircular reduction annuloplasty described by Paneth-Burr. The data on the patients were retrospectively collected. Patients were contacted by outpatient clinic controls for mid-term results.ResultsThe male/female ratio was 10/11. The mean age of the patients was 71.0 ± 6.4 years. Preoperative and postoperative left ventricular ejection fraction was statistically similar (P = 0.973). Early postoperative MR grade (mean, 0.57 ± 0.51) was statistically lower than the preoperative MR grades (mean, 3.38 ± 0.50) (P < 0.001). There was no revision for excess bleeding. Two patients had prolonged hospitalization, one for sternal infection and the other for severe chronic obstructive pulmonary disease. No hospital or late postoperative deaths occurred. The mean late postoperative MR grade was 0.66 ± 0.97 degrees. One patient had progression of MR in the later follow-up, which was treated by mitral valve replacement.ConclusionSemicircular reduction annuloplasty is an effective, inexpensive and easy surgical annuloplasty technique with low mortality and morbidity in severe symptomatic ischemic MR.

In Patients with Post-Infarction Left Ventricular Dysfunction, How Does Impaired Basal Rotation Affect Chronic Ischemic Mitral Regurgitation?

The aim of this study was to explore the contribution of left ventricular (LV) basal rotation to the mechanism of chronic ischemic mitral regurgitation (MR). Fifty-seven patients (52 men; mean age, 68.3 ± 11.8 years) with postinfarction LV dysfunction (defined as an ejection fraction ≤ 45%) were prospectively enrolled. Each invariably had functional MR. To assess MR degree, the effective regurgitant orifice area (EROA) was quantified by echocardiography using the proximal isovelocity surface area method. Furthermore, mitral valve deformation (valve tenting and annular function) and LV global (systolic and diastolic volumes, function, and sphericity) and local remodeling (displacement of papillary muscles, regional strain, and rotation by speckle-tracking) were assessed. The patients were subsequently subdivided into two groups according to the absence (group A) or presence (group B) on transthoracic echocardiography of infarct area in the inferior and/or posterior basal segments. A larger EROA was found in group B than in group A (P = .034) and in subjects with asymmetric rather than symmetric tethering in either group (P = .036 and P = .040 for groups A and B, respectively). Basal radial (P = .009), circumferential (P = .042), and longitudinal (P = .005) strain and rotation (P = .021) were lower in group B than in group A. There was also a significant inverse correlation between EROA and basal rotation in group B (r = -0.75, P < .001). Furthermore, using multivariate linear regression analysis, we found that the independent determinants of EROA were end-diastolic volume (P < .001) and tenting area (P = .004) in group A and asymmetric tethering (P = .029) and basal rotation (P < .001) in group B. Impaired basal rotational mechanics occurring after an inferior-posterior myocardial infarction is associated with increased MR.

Left Ventricular Strain in Chronic Ischemic Mitral Regurgitation in Relation to Mitral Tethering Pattern

The aim of this retrospective study was to explore whether different tethering patterns in chronic ischemic mitral regurgitation have different distributions of left ventricular (LV) systolic longitudinal, circumferential, and radial strain before and after mitral valve repair. Sixty-one patients with chronic ischemic mitral regurgitation who underwent mitral repair were divided on the basis of the preoperative anterior/posterior tethering angle ratio (cutoff value, 0.76). There were 29 patients with symmetric (group 1) and 32 with asymmetric (group 2) preoperative tethering patterns. Assessment of longitudinal peak systolic strain was performed offline by applying speckle-tracking imaging to the apical two-chamber, three-chamber, and four-chamber views of the left ventricle. Peak systolic radial and circumferential strain was obtained from short-axis views at the basal, middle, and apical levels. Twenty healthy subjects served as controls. In group 1, baseline LV strain was impaired in all LV segments, with the worst values in the anterolateral, anterior, and inferolateral segments at the midventricular and basal levels. In contrast, asymmetric patients showed higher values in the inferior and inferoseptal walls and values closer to normal in the other segments. After surgery, all strain measurements showed significant improvements in all LV segments in group 2, whereas in Group 1, strain worsened in the inferoseptal, inferior, and anteroseptal walls and did not change in the other segments. Patients with baseline symmetric tethering patterns showed more extensive abnormal strain, which was observed in all LV segments and was not reverted by surgery. These findings require confirmation in additional larger studies.

In Vitro Mitral Valve Simulator Mimics Systolic Valvular Function of Chronic Ischemic Mitral Regurgitation Ovine Model

This study was undertaken to evaluate an in vitro mitral valve (MV) simulator's ability to mimic the systolic leaflet coaptation, regurgitation, and leaflet mechanics of a healthy ovine model and an ovine model with chronic ischemic mitral regurgitation (IMR). Mitral valve size and geometry of both healthy ovine animals and those with chronic IMR were used to recreate systolic MV function in vitro. A2-P2 coaptation length, coaptation depth, tenting area, anterior leaflet strain, and MR were compared between the animal groups and valves simulated in the bench-top model. For the control conditions, no differences were observed between the healthy animals and simulator in coaptation length (p = 0.681), coaptation depth (p = 0.559), tenting area (p = 0.199), and anterior leaflet strain in the radial (p = 0.230) and circumferential (p = 0.364) directions. For the chronic IMR conditions, no differences were observed between the models in coaptation length (p = 0.596), coaptation depth (p = 0.621), tenting area (p = 0.879), and anterior leaflet strain in the radial (p = 0.151) and circumferential (p = 0.586) directions. MR was similar between IMR models, with an asymmetrical jet originating from the tethered A3-P3 leaflets. This study is the first to demonstrate the effectiveness of an in vitro simulator to emulate the systolic valvular function and mechanics of a healthy ovine model and one with chronic IMR. The in vitro IMR model provides the capability to recreate intermediary and exacerbated levels of annular and subvalvular distortion for which IMR repairs can be simulated. This system provides a realistic and controllable test platform for the development and evaluation of current and future IMR repairs.

Ringless MitraClip therapy: is it time to learn to give up?

I have read with interest the article by Taramasso et al. [1]. They compared retrospectively the efficacy of the MitraClip (percutaneous edge-to-edge [E2E] procedure) with surgical treatment (E2E stitch plus annuloplasty) in patients with severe functional mitral regurgitation (FMR) and heart failure. They concluded that MitraClip therapy is a good alternative, particularly in patients who are not amenable to surgery. It could be that MitraClip improves safety because of its percutaneous deployment. However, one cannot forget the good outcome of the E2E stitch especially when ring annuloplasty is included as a part of the procedure [2]. For those of us who have learned the traditional concepts of Dr Carpentier’s ‘old school’, the use of annuloplasty ring is a requirement in any mitral valve repair [3]. Indeed, the same Milan group found that the best outcome is achieved when E2E is used with ring annuloplasty [2]. Although Maisano et al. [4] demonstrated that it is possible to perform E2E repair without annuloplasty in 29 cases of FMR with an acceptable outcome, a limitation of their study is the small sample size that does not allow to make any firm inference. In addition, we know that, in chronic ischaemic mitral regurgitation, the mitral valve annulus is misshaped and deformed, and tethering forces arising from the adversely remodelled left ventricle towards the mitral valve are responsible for mitral valve regurgitation [5]. So, if we are to learn from our failures, one should conclude that the reshaping of the mitral valve annulus by means of a prosthetic ring is an absolute ‘must’ in the treatment of FMR. This does not mean that we do away with all we have learned about ring annuloplasty. I would propose that long-term follow-up studies are needed to clarify the safety and efficacy of the percutaneous MitraClip therapy without annuloplasty ring for FMR. Keeping in mind that the percutaneous mitral valve annuloplasty has its own shortcomings [6], the role and place of MitraClip therapy in the treatment of FMR are yet to be elucidated.

Ischemic Mitral Regurgitation

Chronic ischemic mitral regurgitation (IMR) is still a significant clinical problem. It is present in 10-20% of patients with coronary artery disease and is associated with a worse prognosis after myocardial infarction and subsequent revascularization. Currently, coronary artery bypass grafting combined with restrictive annuloplasty is the most commonly performed surgical procedure, although novel approaches have been used in limited numbers with varying degrees of success. The purpose of this review is to clarify the rationale for the surgical techniques applicable to IMR. In order to do so, the condition will be defined and the evolution of classic or traditional surgical approaches to repairing or replacing the mitral valve in the setting of IMR will be described. Finally, novel approaches to the repair of the ischemic mitral valve will be considered.

Dynamic Ischaemic Mitral Regurgitation and the Role of Stress Echocardiography.

Objective:This paper aims to explain the main mechanisms that cause ischaemic mitral regurgitation (MR), the pathophysiology, and the role played by stress echocardiography in the evaluation of the dynamic component of MR.Introduction:Chronic ischaemic MR is a frequent complication of myocardial infarction (MI), and is associated with a poor prognosis and outcome. The more the severity of ischaemic MR, the lower is the survival rate. In recent times, improvements in the management of the acute phase of MI, has increased the survival rate after MI. This, combined with an increase in the incidence of MI, will probably lead to a higher prevalence of ischemic MR in the next decades. As a consequence, ischaemic MR should be thoroughly understood and promptly identified. Furthermore, it is well recognized that ischaemic MR is dynamic. The best way to explore the dynamic nature of ischaemic MR is exercise stress echocardiography, and this test should probably be integrated in the evaluation and the management of patients with chronic ischaemic MR.Conclusion:Based on our experience, exercise stress echocardiography might be of interest in the following subsets of patients: 1) in patients with left ventricular (LV) dysfunction who present exertional dyspnea out of proportion to the severity of resting LV dysfunction or MR severity, 2) in patients in whom acute pulmonary oedema occurs without any obvious cause; 3) to unmask patients at high risk of mortality and heart failure 4) before surgical revascularization in patients with moderate ischaemic MR and, 5) following surgery, to identify persistence of pulmonary hypertension and explain the absence of functional class improvement.

Circulation: Clinical Summaries

<i>Circulation:</i> Clinical Summaries