Improvement following correction of secondary mitral regurgitation in end-stage cardiomyopathy with mitral annuloplasty

Secondary Mitral Regurgitation: Updated Review with Focus on Percutaneous Interventional Management

Secondary mitral regurgitation (SMR) is associated with increased mortality and heart failure hospitalizations. The management of heart failure patients with SMR is complex and requires a multidisciplinary Heart Team approach. Guideline-directed medical therapies remain fundamental, yet in a proportion of patients SMR persists. In the past decade, transcatheter edge-to-edge repair (TEER) has been shown to improve survival in patients with SMR who remain symptomatic despite medical therapy. Technical advancements across newer generations of devices, improved imaging, and greater operator expertise have collectively contributed to the increased safety and efficacy of this procedure over time. Various emerging transcatheter mitral valve repair and replacement devices are currently under investigation and may offer superior, complementary or synergistic treatment options in patients ineligible for TEER. This review provides a state-of-the-art overview regarding the diagnosis of SMR, and currently available transcatheter mitral valve interventions and describes a contemporary approach to the management of SMR.

Changes in Left Ventricular Function and Outcomes After Trancatheter Edge-to-Edge Repair for Secondary Mitral Regurgitation

Background

Transcatheter edge-to-edge repair (TEER) improved outcomes in patients with heart failure (HF) and severe secondary mitral regurgitation (SMR) compared with guideline-directed medical therapy (GDMT) alone regardless of the severity of baseline left ventricular ejection fraction (LVEF). The study aimed to evaluate the effect of early changes in LVEF after TEER and GDMT alone in patients with HF and severe SMR.

Methods

Within the COAPT trial, we evaluated outcomes according to changes in LVEF from baseline to 30 days. The primary outcome was all-cause death or HF hospitalization (HFH) between 30 days and 2 years.

Results

Among 432 patients with paired echocardiographic data, 182 (42.1%) had increased LVEF (LVEF change 6.0% ± 4.9%) and 250 (57.9%) had a decrease or no change in LVEF (LVEF change -6.6% ± 5.6%) from baseline to 30 days. LVEF at 30 days increased more frequently with GDMT alone compared with TEER plus GDMT (51.4% vs 33.0%; P = .0001). Between 30 days and 2 years, there were no significant differences in death or HFH in the increase LVEF and the decrease LVEF groups (58.8% vs 51.4%; multivariable-adjusted HR, 0.97; 95% CI, 0.87-1.08; P = .59). TEER plus GDMT reduced the 30-day to 2-year rate of death or HFH compared with GDMT alone consistently in patients with increase LVEF and decrease LVEF (Pint = 0.75).

Conclusions

Among patients with HF and severe SMR, early improvements in LVEF were more frequent with GDMT alone compared with TEER plus GDMT but were not associated with subsequent outcomes at 2 years. TEER reduced death or HFH during 2-year follow-up irrespective of early LVEF changes.

Heart Failure and Secondary Mitral Regurgitation: A Contemporary Review

Secondary mitral regurgitation (SMR) in patients with heart failure (HF) is associated with significant morbidity and mortality. In recent decades, SMR has received increasing scientific attention. Advances in echocardiography, computed tomography and cardiac magnetic resonance imaging have refined our ability to diagnose, quantify and characterize SMR. Concurrently, the treatment options for this high-risk patient population have continued to evolve. Guideline-directed medical therapies including beta-blockers, angiotensin receptor-neprilysin inhibitors, mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors target the underlying cardiomyopathy, and along with diuretics to treat pulmonary congestion, remain the cornerstone of therapy. Cardiac resynchronization therapy also reduces MR, alleviates symptoms and prolongs life in selected HF patients with SMR. While data supporting surgical mitral valve repair or replacement for SMR are limited, transcatheter edge-to-edge repair (TEER) has been demonstrated to improve survival, reduce the rate of hospitalization for heart failure, and improve functional capacity and quality-of-life in select patients with SMR who remain symptomatic despite medical therapy. Emerging transcatheter mitral valve repair and replacement technologies are undergoing investigation in TEER-eligible and TEER-ineligible patients. The optimal management of HF patients with SMR requires a multidisciplinary team of cardiologists, cardiac surgeons, imaging experts, and other organ specialists to select the best treatment approaches to improve the prognosis of these high-risk patients.

Undersizing mitral annuloplasty alters left ventricular mechanics in a swine model of ischemic mitral regurgitation

OBJECTIVE

Undersizing mitral annuloplasty (UMA) is a frequently used surgical repair technique to correct ischemic mitral regurgitation in patients with heart failure. In this study, we sought to test the hypothesis that downsizing the mitral annulus can adversely affect the shape and mechanics of the left ventricle inhibiting its functional recovery.

METHODS

Eighteen farm swine that underwent an inferolateral myocardial infarction and developed ischemic mitral regurgitation of >2+ severity after 2 months were assigned as follows: 9 swine received an undersized mitral annuloplasty, 6 received papillary muscle approximation (PMA), and 3 animals did not receive any other intervention. Animals lived another 3 months and cardiac magnetic resonance imaging was performed before termination to assess ventricle mechanics and function.

RESULTS

Ejection fraction was comparable between the 2 repair groups before surgery, but was significantly lower in UMA at 38.89% ± 7.91% versus 50.83% ± 9.04% in the PMA group (P = .0397). Animals receiving UMA had lower regional peak fractional shortening and reduced systolic and diastolic radial velocities compared with PMA and in some regions were lower than sham. Animals that underwent UMA had higher circumferential strain than sham, but lower than PMA. UMA animals have lower longitudinal strain compared to sham group and lower LV torsion than PMA.

CONCLUSIONS

Undersizing the mitral annulus with an annuloplasty ring can restore valvular competence, but unphysiologically impair ventricle mechanics. Mitral valve repair strategies should focus not only on restoring valve competence, but preserving ventricle mechanics.

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

Background

Undersizing 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.

Methods

An 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.

Results

FMR 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.

Conclusions

This 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.

Guide to functional mitral regurgitation: a contemporary review

Functional mitral regurgitation (FMR) occurs in the absence of organic mitral valve (MV) disease and is a result of LV dysfunction due to ischemic vs. non ischemic etiologies. The prevalence of FMR is increasing, as 2.0-2.5 million people in the USA were diagnosed with FMR in 2000-and this number is expected to double to 4 million by 2030. FMR tends to develop in a significant number of patients after myocardial infarction (MI) and many develop heart failure (HF) subsequently with mortality rates ranging from 15-40% at 1 year. Therefore, there has been much interest and effort to develop optimized methods for quantifying and classifying the severity of FMR, as well as developing effective therapeutic interventions to improve outcomes in patients with significant FMR. Echocardiogram is typically the primary diagnostic method of assessment, however, there have been various technological advances including cardiac CT and cardiac MRI that can better guide quantification and management of this disease. Management of this disease is mostly aimed at optimizing left ventricular (LV) remodeling with surgical and transcatheter management gaining more popularity with recent times. The purpose of this paper is to provide a comprehensive review of the current evaluation methods and interventional strategies for FMR.

The unfinished saga of invasive procedures for secondary mitral regurgitation

Secondary mitral regurgitation (MR) is a common valvular heart disease. Its prognostic burden in patients suffering from idiopathic or ischemic cardiomyopathy (ICM) with left ventricular (LV) dysfunction/dilation has been clearly demonstrated. Severe secondary MR is associated with an increased mortality and frequent heart failure hospitalizations. Although guideline-directed medical therapy (GDMT) is the cornerstone of the management of secondary MR, a certain proportion of patients remain symptomatic. For these patients, several surgical techniques have been progressively developed during the last few decades (replacement, repair, sub-valvular apparatus interventions and other ventricular approaches). In the absence of evidence-based medicine, the benefits of these surgical procedures remains controversial, leading to a low level of recommendation in the guidelines. One way to anticipate the future is to look to the past. Recent prospective randomized trials evaluated surgical and percutaneous techniques and led to a better understanding of how best to treat this disease. In this article, we aim to describe the saga of the surgical and percutaneous treatments for secondary MR throughout the previous decades.

Pathological Remodeling of Mitral Valve Leaflets from Unphysiologic Leaflet Mechanics after Undersized Mitral Annuloplasty to Repair Ischemic Mitral Regurgitation

Background Undersized ring annuloplasty is a commonly used surgical repair for ischemic mitral regurgitation, in which annular downsizing corrects regurgitation, but alters valve geometry and elevates tissue stresses. In this study, we investigated if unphysiological leaflet kinematics after annuloplasty might cause pathogenic biological remodeling of the mitral valve leaflets, and if preserving physiologic leaflet kinematics with a better technique can moderate such adverse remodeling. Methods and Results Twenty-nine swine were induced with ischemic mitral regurgitation, and survivors were assigned to groups: 7 underwent annuloplasty, 12 underwent annuloplasty with papillary-muscle approximation, 6 underwent papillary-muscle approximation, and 3 were sham controls. Pre-and post-surgery leaflet kinematics were measured, and valve tissue was explanted after 3 months to assess biological changes. Anterior leaflet excursion was unchanged across groups, but persistent tethering was observed with annuloplasty. Posterior leaflet was vertically immobile after annuloplasty, better mobile with the combined approach, and substantially ( P=0.0028) mobile after papillary-muscle approximation. Procollagen-1 was higher in leaflets from annuloplasty compared with the other groups. Heat shock protein-47 and lysyl oxidase were higher in groups receiving annuloplasty compared with sham. α- SMA was elevated in leaflets from animals receiving an annuloplasty, indicating activation of quiescent valve interstitial cells, paralleled by elevated transforming growth factor-β expression. Conclusions This is the first study to demonstrate that surgical valve repairs that impose unphysiological leaflet mechanics have a deleterious, pathological impact on valve biology. Surgeons may need to consider restoring physiologic leaflet stresses as well as valve competence, while also exploring pharmacological methods to inhibit the abnormal signaling cascades.

Transcatheter mitral valve intervention: an emerging treatment for mitral regurgitation

Mitral regurgitation (MR) is a valvular heart disease associated with significant morbidity and mortality. Transcatheter mitral valve intervention (TMVI) repairs or replaces the mitral valve through small arterial and venous entry sites and so avoids risks associated with open heart surgery. Transcatheter devices targeting components of the mitral apparatus are being developed to repair or replace it. Numerous challenges remain including developing more adaptable devices and correction of multiple components of the mitral annulus to attain durable results. The mitral valve apparatus is a complex structure and understanding of the mechanisms of MR is essential in the development of TMVI. There will likely be a complementary role between surgery and TMVI in the near future.

Transcatheter Mitral Valve Therapy: Defining the Patient Who Will Benefit

PURPOSE OF REVIEW

This report aims to define the clinical and anatomic variables key in determining patient suitability for transcatheter mitral valve therapies.

RECENT FINDINGS

Candidacy for transcatheter mitral valve repair requires weighing the clinical variables that may impact the ability to improve patient symptoms and prolong survival that include left ventricular ejection fraction, symptom severity, pulmonary hypertension, and magnitude of residual regurgitation or stenosis. Individualized selection of transcatheter repair or replacement based on patho-anatomy is being explored. The primary goal is achieving significant reduction in mitral regurgitation. Transcatheter mitral valve replacement requires rigorous anatomic screening using computed tomography and candidates should be able to take oral anticoagulation. Selection of patients for transcatheter mitral valve repair is complex and requires intimate knowledge of clinical variables and specific device limitations.

Percutaneous Mitral Valve Technology: What Is on the Horizon?

Mitral valve disease is common, with mitral regurgitation (MR) being the most frequent pathology. The etiology of MR is diverse, but, if left untreated, MR results in left ventricular (LV) volume overload, leading to remodeling, dilation of the LV, pulmonary hypertension, heart failure, and death. Mitral regurgitation is a high-risk diagnosis, yet a minority of symptomatic patients are referred for discussion of surgical treatment options. Percutaneous repair options are under development to address this clinical need and emphasize correction of the underlying anatomical pathology to restore mitral valve coaptation. Transcatheter mitral valve replacement is in the early stages of development and may prove safe and effective in certain patient populations. Investigational devices are challenging our current thinking about the management of mitral valve disease, and it will be the task of the multidisciplinary Heart Team to determine the right device for the right pathology.

Valve Repair: A "Bridge" to Heart Transplant

Cardiac transplants are limited because of a deficiency of donor organs. Most recipients with severe chronic heart failure are on a waiting list. Therefore, palliative surgical treatment of chronic heart failure is widely used. We report a case of successful application of palliative surgical approach for a patient with decompensated heart failure.

Catheter-based or surgical repair of the highest risk secondary mitral regurgitation patients

Surgical mitral valve repair (MVR) remains the standard of care for patients with severe valve incompetence with clear, proven benefit for patients with primary mitral regurgitation (MR). Secondary MR is a primary disease of the left ventricular (LV) myocardium. Up to 50% of patients develop secondary MR after an acute myocardial infarction (ischemic MR), with approximately 10% of these having severe MR. It is controversial as to whether surgical MVR is beneficial for these patients because valve repair or replacement does not correct the underlying disease. The increased perioperative risk due to decreased LV function makes clinical decision-making even more complex. The recently introduced less-invasive, catheter-based therapies are potential promising solutions for this dilemma. While the MitraClip device is already in widespread clinical use as a viable therapeutic option in higher-risk patients with primary MR and currently in investigational trials for secondary MR, several other devices for both repair and replacement are currently undergoing feasibility trials. Due to the complex structure of the mitral valve, the development of transcatheter mitral valve replacement has been much slower than that of transcatheter aortic valve replacement, but this approach may be an attractive therapeutic option in the future. Currently, the role of surgical therapy in comparison to transcatheter techniques in secondary MR is not well defined.

Outcome after mitral valve operations with depressed left ventricular function

We retrospectively investigated 42 patients (27 men, 15 women; mean age, 67 years) with severe mitral valve incompetence and endstage cardiomyopathy (ejection fraction<30%) who were operated on between January 2002 and March 2009. Of these, 14 were in New York Heart Association class IV, and 27 were in class III. The etiology was ischemic in 18 patients and idiopathic dilated in 24. Mitral valve repair was performed in 25 patients, and 17 had mitral valve replacement. The mean logistic EuroSCORE was 33.41. The mean follow-up was 44.52 months. There were no perioperative deaths. Three patients died within 30 days postoperatively. Thirty-day mortality was lower than predicted by EuroSCORE (7.14% vs. 33.41%). The median functional class improved from 3 to 2 during follow-up. Ejection fraction improved from 24% to 42% at 6 weeks, then decreased to 33%. The midterm survival rate was 86%, and 81% after 1 and 2 years. Freedom from reoperation at 2 years was 85%; 6 patients needed reoperation for recurrent mitral regurgitation. Despite high operative risk, mitral valve surgery can be performed successfully with acceptably low mortality in patients with endstage cardiomyopathy. Patients experience substantial clinical improvement and a moderate recovery of left ventricular function.

Mitral valve surgery for dilated cardiomyopathy: current status and future roles

There are a large number of patients with functional mitral regurgitation resulting from dilated cardiomyopathy. The decision between surgical correction and medical management of severe mitral regurgitation in heart failure can be difficult. The data regarding long-term benefits and mortality after surgical intervention are contradictory. Recent data suggest that mitral regurgitation can be surgically corrected in heart failure with symptomatic improvements and beneficial reverse remodeling. Contrary to prior beliefs, mitral valve repair can be performed safely with minimal postoperative mortality. Data from multi-institutional, randomized prospective trials will help to elucidate many of the questions and concerns regarding repair of severe functional mitral regurgitation.

Who needs a transplant and when?

PURPOSE OF REVIEW

Heart transplantation remains the treatment of choice for patients with advanced heart failure. We review the current definition of optimal therapy, prediction of prognosis and revisit contraindications for transplant.

RECENT FINDINGS

Clinical trials of eplerenone and ivabradine were associated with improved prognosis, whereas others (nesiritide) were disappointing. Advances in cardiac resynchronization therapy and ventricular assist devices (VAD) have resulted in an expansion of their indications. Advances in catheter ablation for ventricular tachycardia have made this an uncommon indication for heart transplantation. Surgical ventricular reconstruction and mitral valve intervention have not resulted in survival benefit. Bypass surgery was associated with a lower mortality from cardiovascular causes. Prognostic risk scores have been developed in heart failure patients; however, ongoing refinements are needed. Selected patients with diabetes, HIV and pretransplant malignancy, now have favourable outcomes after heart transplantation. VAD as bridge to candidacy is an option in heart failure patients with 'fixed' pulmonary hypertension. Alternate listing strategies have also been studied to provide high-risk patients with an opportunity for heart transplantation.

SUMMARY

Heart failure patients should be on current optimal medical and device therapy with a poor prognosis before consideration for heart transplantation. An individualized approach to heart transplantation assessment is recommended.

Left ventricular mechanics following restrictive mitral annuloplasty for functional mitral regurgitation: two-dimensional speckle tracking echocardiographic study

BACKGROUND

Restrictive mitral annuloplasty (RMA) is widely employed for patients with functional mitral regurgitation (MR). Its improvement of left ventricular (LV) function has been demonstrated by only a gradual increase in LV ejection fraction (EF) in the chronic phase. However, the detailed evaluation of changes in LV function has not been fully elucidated in functional MR patients before and after RMA. Therefore, we performed two-dimensional speckle tracking echocardiography (2D-STE), which enables accurate evaluation of myocardial deformation and rotation that are undetectable by conventional echocardiography.

METHODS

We studied 13 patients (mean age 61 ± 10 years) with functional MR associated with cardiomyopathy undergoing RMA. In addition to conventional echocardiographic measurements, 2D-STE was performed to measure peak systolic radial (RS), circumferential (CS), and longitudinal (LS) strains and twist before and 4 ± 2 weeks after surgery. LV twist was defined as the difference between the apical and basal rotations.

RESULTS

After RMA, EF and LS remained unchanged, but RS and CS were significantly improved at the mid-LV (RS, 20.6 ± 10.8 vs 24.5 ± 11.6%; CS, -9.6 ± 5.2 vs -12.8 ± 5.6%) and at the apex (RS, 15.0 ± 12.2 vs 18.7 ± 8.6%; CS, -4.4 ± 3.0 vs -7.8 ± 4.8%). RS and CS were unchanged at the base. The apical and basal rotations changed significantly, from 3.5°± 0.7° to 9.2°± 2.1°, and -2.1°± 0.7° to -3.8°± 1.0°, respectively. Consequently, the LV twist increased significantly, from 5.6°± 1.0° to 13.0°± 1.9°.

CONCLUSIONS

Radial and circumferential strains and LV twist increased significantly in the early postoperative period in functional MR patients after RMA and concomitant procedures.

Impact of preoperative anterior leaflet tethering on the recurrence of ischemic mitral regurgitation and the lack of left ventricular reverse remodeling after restrictive annuloplasty

BACKGROUND

The aim of this multicenter study was to investigate the impact of the preoperative anterior mitral leaflet tethering angle, α', on the recurrence of mitral regurgitation (MR) and left ventricular (LV) reverse remodeling (LVRR) after undersized mitral ring annuloplasty.

METHODS

The study population consisted of 362 patients, who were divided into two groups by baseline α': group 1, α' < 39.5° (n = 196), and group 2, α' ≥ 39.5° (n = 166). End points were recurrent MR ≥ 2+; LVRR, defined as a reduction in end-systolic volume index > 15%; and LV geometric reverse remodeling, defined as a reduction in systolic sphericity index to a normal value of <0.72 in patients with altered baseline geometry.

RESULTS

MR occurred in 9.6% (n = 19) and 43.3% (n = 72) of the patients in groups 1 and 2, respectively (P < .001). LVRR (85.7% vs 22.2%) at follow-up was higher in group 1 (P < .001). On multivariate regression analysis, α' ≥ 39.5° was a strong predictor of MR recurrence, lack of LV reverse remodeling and lack of LV geometric reverse remodeling (all P values < .001). In contrast, the posterior mitral leaflet tethering angle, β', was not significant (all P values > .05). When we allowed for interactions between α' and other risk factors, this effect occurred also in low-risk subgroups, and it was equivalent or generally attenuated in higher risk patients. There were no significant interactions between α' and any of the covariates (all P values > .05).

CONCLUSIONS

Anterior mitral leaflet tethering is a powerful predictor of MR recurrence and lack of LVRR after undersized mitral ring annuloplasty. Evaluation of leaflet tethering should be incorporated into clinical risk assessment and prediction models.

Percutaneous mitral valve interventions: overview of new approaches

The percutaneous management of valvular heart disease has recently been receiving a great deal of interest as an area of great potential. Innovative technologies are now being developed to treat mitral regurgitation. Although there are established surgical techniques for treating organic mitral regurgitation, the surgical management of functional mitral regurgitation remains controversial, and such patients have a poor prognosis. Therefore, a percutaneous treatment for functional mitral regurgitation holds great clinical potential. Having a nonsurgical approach available may be attractive to patients with organic mitral valve regurgitation as well. Several approaches and devices have been designed to treat specifically functional mitral regurgitation, and some of these have been applied to humans in early-stage evaluations. The MitraClip device (Abbott Laboratories, Abbott Park, IL) has been used to treat both functional and degenerative mitral valve regurgitation and has been compared to surgery in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study II) randomized trial. Although the field of percutaneous management of mitral regurgitation is at an early stage, it has been demonstrated that percutaneous approaches can reduce mitral regurgitation, suggesting there is a great deal of potential for clinical benefit to patients with mitral regurgitation.

Surgical treatment of functional mitral regurgitation in dilated cardiomyopathy

Functional mitral regurgitation is a significant complication of end-stage cardiomyopathy. Dysfunction of one or more components of the mitral valve apparatus occurs in 39-74% and affects almost all heart failure patients. Survival is decreased in subjects with more than mild mitral regurgitation irrespective of the aetiology of heart failure. The goal of treating functional mitral regurgitation is to slow or reverse ventricular remodelling, improve symptoms and functional class, decrease the frequency of hospitalization for congestive heart failure, slow progression to advanced heart failure (time to transplant) and improve survival. This article reviews the role of mitral valve surgery in patients with heart failure and dilated cardiomyopathy.

Impact of MitraClip™ therapy on secondary mitral valve surgery in patients at high surgical risk

OBJECTIVE

Conventional or minimally invasive surgical mitral valve repair (MVR) is the gold-standard treatment for severe mitral regurgitation (MR) of any etiology. Given its good safety profile, trans-catheter MVR with the MitraClip™ device is used increasingly for high-risk or inoperable patients. We report our experience with failed MitraClip™ therapy and its impact on subsequent surgical strategies, such as the feasibility of MVR in high-risk patients.

METHODS

During a follow-up of 344 ± 227 days from the first 215 consecutive patients treated with the MitraClip™ device, six patients required surgical re-intervention due to failed repair (n = 3) or recurrent severe MR (n = 3) at 35.8 ± 47.7 (range 0-117) days after trans-catheter MVR. Feasibility of secondary surgical MVR was assessed with regard to prior clip therapy.

RESULTS

In three patients, secondary surgical MVR was successfully performed following the surgical strategy deemed optimal before trans-catheter treatment. Injury of the mitral leaflets caused by prior clip treatment was present in three other patients and influenced the surgical strategy toward more complex surgical techniques in one case and MV replacement in two others. One patient died 6 days after MV replacement. All other patients are alive with adequate valve function at the latest follow-up of 12.4 ± 7.4 months (range 4-22).

CONCLUSIONS

Secondary surgical MVR was feasible in some patients after prior clip treatment, but led to valve replacement in others. At present, patient selection criteria for trans-catheter MVR should not be expanded toward more healthy patients, as primary trans-catheter MVR may complicate secondary surgery in certain cases and may even preclude reconstructive valve surgery.

Transcatheter cardiac valve interventions

Currently aortic valve replacement is performed for patients with severe aortic stenosis and symptoms or objective pathophysiologic consequences such as left ventricular dysfunction. For transcatheter mitral valve interventions, the complex pathophysiology of mitral regurgitation with varying causes along with challenging imaging and delivery issues has led to slower than anticipated clinical introduction. Transcatheter pulmonary valve intervention was primarily designed to treat the difficult problem of right ventricular to pulmonary artery conduit stenosis in the congenital population. These techniques are reviewed in this article.

A novel method of percutaneous mitral valve repair for ischemic mitral regurgitation

OBJECTIVES

This investigation sought to determine the feasibility of a novel method of a percutaneous mitral valve repair.

BACKGROUND

Percutaneous mitral valve repair has emerged as an alternative therapy for patients with functional mitral regurgitation. However, current methods that rely on cannulation of the coronary sinus may not result in direct reduction of the mitral annulus area due to the superior relationship of the sinus to the annulus.

METHODS

A novel device, consisting of helical stainless steel screws connected by a biocompatible tether, was designed for percutaneous mitral valve repair. This device was implanted by implanting the helical screws directly into the myocardium at the posteromedial mitral annulus of 8 anesthetized pigs from the right internal jugular vein.

RESULTS

Implantation of the device resulted in a 19.7 +/- 0.1% reduction in mitral annular area and an 18.8 +/- 0.1% decrease in the mitral anterior-posterior dimension (both p < 0.05 vs. baseline). This annular reduction persisted at 3-month follow-up. Both the coronary sinus and left circumflex coronary artery remained patent in all animals. There was no evidence of device migration, poor wound healing, or tissue thrombosis at the sites of device implantation.

CONCLUSIONS

Percutaneous mitral valve repair targeting the ventricular myocardium from central venous access is feasible. By directly acting on the posteromedial mitral annulus, this methodology targets the mitral annular area most frequently affected by ischemic mitral regurgitation, lessens the risk of coronary artery impingement, promotes coronary sinus patency, and overcomes technical concerns that may arise when the coronary sinus lies significantly superior to the mitral annulus.

Percutaneous mitral annuloplasty

Mitral annuloplasty is the most common surgical procedure performed for mitral valve regurgitation, whether performed alone or as part of a more complex repair. A less invasive percutaneous approach to mitral annuloplasty associated with lesser morbidity might offer advantages over a surgical procedure in some patients, even if less efficacious. We review current experimental percutaneous approaches to mitral annuloplasty.

Surgical therapy for mitral regurgitation: the key to preventing heart failure?

Five million Americans suffer from heart failure (HF). Despite innovative new pharmacologic and device therapies, the 5-year mortality rate for patients remains near 50%. Conservatively, 300,000 patients with HF also have severe functional mitral regurgitation. Over the past decade, the surgical approach to these patients has become more aggressive because the extent of the problem has become widely recognized, and surgeon familiarity with annuloplasty techniques has increased. Although clinical experience and enthusiasm have resulted in an expansion of literature, the role that mitral valve repair surgery plays in the treatment of HF is not fully established. In this article, we review the existing data on the efficacy of mitral valve surgery in HF patients. Specifically, we will review the available data regarding the effect of mitral valve surgery on longevity, ventricular remodeling, and symptoms. No randomized prospective data are available, but careful analysis of existing retrospective studies allows important conclusions to be made.