Randomized trial comparing partial versus complete chordal-sparing mitral valve replacement: effects on left ventricular volume and function

Management of Severe Mitral Regurgitation in Patients With Acute Myocardial Infarction: JACC Focus Seminar 2/5

Severe acute mitral regurgitation after myocardial infarction includes partial and complete papillary muscle rupture or functional mitral regurgitation. Although its incidence is <1%, mitral regurgitation after acute myocardial infarction frequently causes hemodynamic instability, pulmonary edema, and cardiogenic shock. Medical management has the worst prognosis, and mortality has not changed in decades. Surgery represents the gold standard, but it is associated with high rates of morbidity and mortality. Recently, transcatheter interventions have opened a new door for management that may improve survival. Mechanical circulatory support restores vital organ perfusion and offers the opportunity for a steadier surgical repair. This review focuses on the diagnosis and the interventional management, both surgical and transcatheter, with a glance on future perspectives to enhance patient management and eventually decrease mortality.

Rough-zone suspension with mitral valve replacement for ventricular functional mitral regurgitation

Chordal preservation is recommended in mitral valve replacement for functional mitral regurgitation to preserve left ventricular function. In contrast, papillary muscle suspension toward the anterior mitral annulus can induce left ventricular reverse remodeling after mitral valve replacement for functional mitral regurgitation. However, the extent of suspension depends on the surgeon's experience. Therefore, we developed a new concept of chordal preservation, called rough-zone suspension, which not only spares the subvalvular structure but also suspends the papillary muscles toward the annulus. This procedure is simple and reproducible for determining the extent of suspension, and can increase the probability of left ventricular reverse remodeling after mitral valve replacement for functional mitral regurgitation.

Early and long-term outcomes of mitral valve replacement with mechanical valve in rheumatic heart disease

Background

Rheumatic fever and rheumatic heart disease is endemic in India. Mitral valve replacement with mechanical valve is the commonest surgical procedure performed in rheumatic heart disease (RHD). However, there are no studies reporting the long-term outcomes of mechanical mitral valve replacement in rheumatic heart disease from India.

Objective

The primary objective of the study was to look at the long-term survival following mechanical mitral valve replacement in RHD. The secondary objectives included follow up complications and event-free survival.

Methods

For this study, 238 patients who underwent mitral valve replacement with TTK Chitra™ valve from 1st January 2006 to 31st December 2018 for RHD were included for analysis and reporting. The median follow-up period was 3371.50 days (9.3 years). Total follow-up was 2044 patient-years.

Results

The mean age of the study population was 39.72 ± 10.48 years (range: 18-68 years). Out of 238 patients operated, 155 patients (65.12%) were alive and 69 patients (28.99%) were dead, and 14 patients (5.88%) were lost to follow-up. The operative mortality was 6 (2.52%) and the follow-up mortality was 63 (26.47%). The reasons for follow-up mortality were cardiac complications in 22 (34.9%) patients, valve-related complications in 18 (28.5%) patients, sudden unexplained death in 13 (20.6%) patients, and non-valve/ non-cardiac death in 10patients (15.8%). The one-year survival was 94.0%, five-year survival was 83.6%, ten-year survival was 70.6% and 15-year survival was 62.9%. During follow-up, valve-related events occurred in 123(52%) patients. The 15-year event-free survival was 33.0%.

Conclusions

The long term outcome of mechanical valve replacement of the mitral valve in RHD patients was less than favorable. Both cardiac complications and mechanical valve related complications reduced their survival.

A Literature Review on the Use of Aortic Allografts in Modern Cardiac Surgery for the Treatment of Infective Endocarditis: Is There Clear Evidence or Is It Merely a Perception?

Infective valve endocarditis is caused by different pathogens and 60% of those involve the aortic valve with valve failure. Although S. aureus is recognized as the most frequently isolated causative bacterium associated with IE in high-income countries, Gram-positive cocci nevertheless play a crucial role in promoting infection in relation to their adhesive matrix molecules. The presence of pili on the surface of Gram-positive bacteria such as in different strains of Enterococcus faecalis and Streptococcus spp., grants these causative pathogens a great offensive capacity due to the formation of biofilms and resistance to antibiotics. The indications and timing of surgery in endocarditis are debated as well as the choice of the ideal valve substitute to replace the diseased valve(s) when repair is not possible. We reviewed the literature and elaborated a systematic approach to endocarditis management based on clinical, microbiological, and anatomopathological variables known to affect postoperative outcomes with the aim to stratify the patients and orient decision making. From this review emerges significant findings on the risk of infection in the allograft used in patients with endocarditis and no endocarditis etiology suggesting that the use of allografts has proved safety and effectiveness in patients with both pathologies.

Cardiac reverse remodeling in primary mitral regurgitation: mitral valve replacement vs. mitral valve repair

BACKGROUND

When feasible, guidelines recommend mitral valve repair (MVr) over mitral valve replacement (MVR) to treat primary mitral regurgitation (MR), based upon historic outcome studies and transthoracic echocardiography (TTE) reverse remodeling studies. Cardiovascular magnetic resonance (CMR) offers reference standard biventricular assessment with superior MR quantification compared to TTE. Using serial CMR in primary MR patients, we aimed to investigate cardiac reverse remodeling and residual MR post-MVr vs MVR with chordal preservation.

METHODS

83 patients with ≥ moderate-severe MR on TTE were prospectively recruited. 6-min walk tests (6MWT) and CMR imaging including cine imaging, aortic/pulmonary through-plane phase contrast imaging, T1 maps and late-gadolinium-enhanced (LGE) imaging were performed at baseline and 6 months after mitral surgery or watchful waiting (control group).

RESULTS

72 patients completed follow-up (Controls = 20, MVr = 30 and MVR = 22). Surgical groups demonstrated comparable baseline cardiac indices and co-morbidities. At 6-months, MVr and MVR groups demonstrated comparable improvements in 6MWT distances (+ 57 ± 54 m vs + 64 ± 76 m respectively, p = 1), reduced indexed left ventricular end-diastolic volumes (LVEDVi; - 29 ± 21 ml/m2 vs - 37 ± 22 ml/m2 respectively, p = 0.584) and left atrial volumes (- 23 ± 30 ml/m2 and - 39 ± 26 ml/m2 respectively, p = 0.545). At 6-months, compared with controls, right ventricular ejection fraction was poorer post-MVr (47 ± 6.1% vs 53 ± 8.0% respectively, p = 0.01) compared to post-MVR (50 ± 5.7% vs 53 ± 8.0% respectively, p = 0.698). MVR resulted in lower residual MR-regurgitant fraction (RF) than MVr (12 ± 8.0% vs 21 ± 11% respectively, p = 0.022). Baseline and follow-up indices of diffuse and focal myocardial fibrosis (Native T1 relaxation times, extra-cellular volume and quantified LGE respectively) were comparable between groups. Stepwise multiple linear regression of indexed variables in the surgical groups demonstrated baseline indexed mitral regurgitant volume as the sole multivariate predictor of left ventricular (LV) end-diastolic reverse remodelling, baseline LVEDVi as the most significant independent multivariate predictor of follow-up LVEDVi, baseline indexed LV end-systolic volume as the sole multivariate predictor of follow-up LV ejection fraction and undergoing MVR (vs MVr) as the most significant (p < 0.001) baseline multivariate predictor of lower residual MR.

CONCLUSION

In primary MR, MVR with chordal preservation may offer comparable cardiac reverse remodeling and functional benefits at 6-months when compared to MVr. Larger, multicenter CMR studies are required, which if the findings are confirmed could impact future surgical practice.

Splitting the anterior mitral leaflet impairs left ventricular function in an ovine model

OBJECTIVES

During mitral valve replacement, the anterior mitral leaflet is usually resected or modified. Anterior leaflet splitting seems the least disruptive modification. Reattachment of the modified leaflet to the annulus reduces the annulopapillary distance. The goal of this study was to quantify the acute effects on left ventricular function of splitting the anterior mitral leaflet and shortening the annulopapillary distance.

METHODS

In 6 adult sheep, a wire was placed around the anterior leaflet and exteriorized through the left ventricular wall to enable splitting the leaflet in the beating heart. Releasable snares to reduce annulopapillary distance were likewise positioned and exteriorized. A mechanical mitral prosthesis was inserted to prevent mitral incompetence during external manipulations of the native valve. Instantaneous changes in left ventricular function were recorded before and after shortening the annulopapillary distance, then before and after splitting the anterior leaflet.

RESULTS

After splitting the anterior leaflet, preload recruitable stroke work, stroke work, stroke volume, cardiac output, left ventricular end systolic pressure and mean pressure were significantly decreased by 26%, 23%, 12%, 9%, 15% and 11%, respectively. Shortening the annulopapillary distance was associated with significant decreases in the end systolic pressure volume relationship, preload recruitable stroke work, stroke work and left ventricular end systolic pressure by 67%, 33%, 15% and 13%, respectively. Shortening the annulopapillary distance after splitting the leaflet had no significant effect.

CONCLUSIONS

Splitting the anterior mitral leaflet acutely impaired left ventricular contractility and haemodynamics in an ovine model. Shortening the annulopapillary distance after leaflet splitting did not further impair left ventricular function.

A Surgical Technique to Preserve the Subvalvular Apparatus in Patients Undergoing Mitral Valve Replacement for Severe Ischemic Regurgitation

Severe functional mitral valve regurgitation should be treated in patients undergoing myocardial revascularization. When replacement is considered the best therapeutic option, preservation of the mitral subvalvular apparatus is crucial, especially in the emergency setting, because of its primary role in preserving geometry and function of left and right ventricles. Here we present a simple and quick technique, where subvalvular apparatus is preserved in toto in patients undergoing mitral valve replacement with a bioprosthesis.

The impact of complete versus partial preservation of the sub-valvular apparatus on left ventricular function in mitral valve replacement

INTRODUCTION

In mitral valve replacement (MVR), sudden increases in afterload and disruption of the annular-chordal-papillary-left-ventricular wall causes left ventricular (LV) dysfunction in the early postoperative period. Preservation of the posterior mitral leaflet apparatus (MVR-P) has a favorable outcome on LV function. However, there is paucity of data on the impact of complete preservation of the sub-valvular apparatus (MVR-C).

OBJECTIVE

We investigated the impact of MVR-P and MVR-C on baseline and 3-months postoperative LV ejection fraction (EF) and global longitudinal strain (GLS).

METHODS

We retrospectively analyzed a cohort of 29 MVR-P and 19 MVR-C patients with complete echocardiography data at our unit, who were operated between 2008 and 2017. Between-group changes in LVEF and GLS were compared using independent sample T-test.

RESULTS

Median age was 59 years (IQR 50-69 years). Baseline LVEF was 58% (51%- 60%). Baseline GLS was -18.4 (-21.2 to -15.5). There were no significant between-group differences between all baseline demographics and echocardiographic markers. There was significantly higher absolute postoperative LVEF in MVR-C patients (p = 0.029). There was also significant worsening in LVEF (p = 0.0121) and GLS (p < 0.0001) after MVR-P and not MVR-C, suggesting no reduction in LV function post-MVR-C but a reduction post-MVR-P. There was significantly less postoperative worsening of GLS per patient in MVR-C group as compared to the MVR-P group (p = 0.023), indicating better preservation of LV function. There was also a smaller decline in LVEF per patient in the MVR-C as compared to the MVR-P group, although not statistically significant (p = 0.23).

CONCLUSION

MVR with complete preservation of the sub-valvular apparatus shows a favorable impact on the longitudinal function of the heart at 3 months. Further studies with larger patient numbers are indicated to investigate the long-term results of this surgical approach.

Acute Ischaemic Mitral Valve Regurgitation

Acute ischaemic mitral regurgitation (IMR) is an increasingly rare and challenging complication following acute myocardial infarction. Despite recent technical advances in both surgical and percutaneous interventions, a poor prognosis is often associated with this challenging patient cohort. In this review, we revisit the diagnosis and typical echocardiographic features, and evaluate current surgical and percutaneous treatment options for patients with acute IMR.

Modified chordal sparing mitral valve replacement as effective technique for both stenotic and insufficient mitral valves

BACKGROUND

Chordal apparatus preservation is important for preserving left ventricular (LV) function in the long-term perspective. We present results of originally modified chordal-sparing mitral valve replacement (MVR) successfully used in patients with mitral stenosis and mitral insufficiency.

METHODS

The modified surgical method involves preserving only four strut chords with portions of the mitral valve leaflets, which are later fixed to the fibrous ring. The rest of the leaflets and marginal chords are removed.

RESULTS

Starting from 1998, 484 modified universal chordal-sparing MVR were performed including 270 (55.79%) in patients with rheumatic mitral stenosis and 214 (44.21%) in patients with mitral valve insufficiency. Overall, 116 patients underwent isolated MVR, and 368 patients underwent MRV with concomitant surgical procedures. The overall in-hospital mortality was 2.5% (12 patients). Long-term efficiency was assessed in patients discharged after isolated MVR (114 patients), average follow-up period was 3.1±0.6 years. Preservation of strut chords ensured normalization of intraventricular anatomy and prevented LV dilatation; the LV Sphericity Index is maintained at 0.44-0.63. Heart failure functional class (NYHA) was improved in all patients. Non-fatal prosthesis-related complications were observed in 11 patients (9.65%). Three patients (2.63%) died due to extracardiac causes.

CONCLUSIONS

The proposed modification of the strut chordal-sparing mitral valve replacement technique allows preserving functionally complete annulo-papillary apparatus, regardless of the nature of valvular dysfunction, and provides parallel movement to the mechanical prosthesis. This modified surgical technique is safe and effective and eliminates the risk of jamming of the prosthesis disk and left ventricular outflow tract obstruction.

Surgical mitral valve repair technique considerations based on the available evidence

Mitral valve regurgitation is the second most common valve disease in the western world. Surgery is currently the best tool for generating a long-lasting elimination of mitral valve regurgitation. However, the mitral valve apparatus is a complex anatomical and functional structure, and repair results and durability show substantial heterogeneity. This is not only due to differences in the underlying mitral valve regurgitation pathophysiology but also due to differences in repair techniques. Repair philosophies differ substantially from one surgeon to the other, and consensus for the technically best repair strategy has not been reached yet. We had previously addressed this topic by suggesting that ring sizing is "voodoo". We now review the available evidence regarding the various repair techniques described for structural and functional mitral valve regurgitation. Herein, we illustrate that for structural mitral valve regurgitation, resuspension of prolapsing valve segments or torn chordae with polytetrafluoroethylene sutures and annuloplasty can generate the most durable results paired with the best achievable hemodynamics. For functional mitral valve regurgitation, the evidence suggests that annuloplasty alone is insufficient in most cases to generate durable results, and additional subvalvular strategies are associated with improved durability and possibly improved clinical outcomes. This review addresses current strategies but also implausibilities in mitral valve repair and informs the mitral valve surgeon about the current evidence. We believe that this information may help improve outcomes in mitral valve repair as the heterogeneity of mitral valve regurgitation pathophysiology does not allow a one-size-fits-all concept.

Mitral valve repair or replacement. How long is this feud to last?

Choosing to perform mitral valve (MV) repair or replacement remains a hot and highly debated topic. The current guidelines seem to be conflicting in this specific field and the evidence at our disposal are scarce, only one small randomized trial and few larger retrospective studies. The meta‐analysis by Gamal and coworkers tries to summarize the current evidence, concluding that MV replacement for the treatment of ischemic mitral regurgitation (MR) is at least as safe as repair and certainly offers a more stable result over time than the latter. Obviously, the implantation of a prosthesis, especially a mechanical one, brings with it a series of problems, such as anticoagulation and, above all, a possible lack of ventricular remodeling, especially if a chordal sparing replacement is not performed. It must be said, on the other hand, that isolated annuloplasty cannot act as a counterpart to replacement, because ischemic MR cannot be considered only an annular disease. Therefore, wanting to mimic the nature that, after an infarction, enacts a series of changes involving also the mitral leaflets and chordae, the surgeons are called to act also on these two entities and not only to downsize the annulus. In a nutshell, a procedure should not be opposed in a fundamentalist way to another one, but we must accept the concept of armamentarium where both procedures are present and tail on the single patient, and also on the surgeon's expertize, the technique guaranteeing the best possible result.

Incorporating the anterior mitral leaflet to the annulus impairs left ventricular function in an ovine model

Objectives

Transcatheter mitral valve prostheses are designed to capture the anterior leaflet and surgical techniques designed to fully preserve the subvalvular apparatus at prosthetic valve insertion both serve to shorten the anterior mitral leaflet height, thus effectively incorporating it into the anterior annulus. This study quantifies the acute effects of incorporating the anterior mitral leaflet into the annulus on left ventricular function.

Methods

Fourteen adult sheep (weight, 48.7 ± 6.2 kg) underwent a mechanical mitral valve insertion on normothermic beating-heart cardiopulmonary bypass, with full retention of the native mitral valve but with placement of exteriorized releasable snares around the anterior mitral leaflet. Continuous measurements of left ventricular mechano-energetics were recorded throughout, alternating incorporating and releasing of the anterior mitral leaflet to the mitral annulus. Echocardiography confirmed the incorporation into the annulus and release.

Results

The independent indices of left ventricular contractility (ie, end systolic pressure volume relationship and preload recruitable stroke work) were both significantly impaired when the anterior mitral leaflet was incorporated to the annulus and restored after release, as were the hemodynamic parameters: cardiac output, stroke volume, stroke work, and left ventricular pressure decreased by 15%, 17%, 23%, and 11%, respectively. Echocardiography demonstrated increased sphericity of the left ventricle during anterior mitral leaflet incorporation.

Conclusions

Incorporating the anterior mitral leaflet to the anterior annulus adversely affected left ventricular contractility, caused distortion of the left ventricle in the form of increased sphericity, and impaired hemodynamic parameters in normal ovine hearts.

Exploring the Operative Strategy for Secondary Mitral Regurgitation: A Systematic Review

Background

Mitral valve disease surgery is an evolving field with multiple possible interventions. There is an increasing body of evidence regarding the optimal strategy in secondary mitral regurgitation where the pathology lies within the ventricle. We conducted a systematic review to identify the benefits and limitations of each surgical option.

Methods

A systematic review of the literature was performed to identify pertinent randomized controlled trials (RCTs), propensity-matched observational series, and meta-analyses which were considered initially and followed by unmatched observational series using the MEDLINE, Ovid EMBASE, and Cochrane Library.

Results

We identified 6 different strategies for treating secondary mitral valve regurgitation: mitral valve replacement, restrictive mitral annuloplasty, surgical revascularization (with and without mitral annuloplasty), subvalvular procedures (papillary muscle approximation, papillary muscle relocation, ring and string procedure), and procedures directly targeting the mitral valve (edge-to-edge repair and anterior leaflet enlargement) alongside transcatheter heart valve therapy. We also highlighted the role of left ventricular assist devices in the management of this condition. The benefits and limitations of each intervention are highlighted.

Conclusion

There is currently no unanimous and shared strategy for the optimal treatment of patients with secondary IMR. The management of patients with secondary mitral regurgitation must be entrusted to a multidisciplinary Heart Team to ensure ideal intervention and patient matching for the best outcomes.

Ischemic functional mitral regurgitation: from pathophysiological concepts to current treatment options. A systemic review for optimal strategy

OBJECTIVE

The current treatment of ischemic functional mitral regurgitation (FMR) remains debated due to differences in inclusion criteria of randomized studies and baseline characteristics. Also, the role of left ventricular pathophysiology and the role of subvalvular apparatus have not been thoroughly investigated in recent literature.

METHODS

A literature search was performed from PubMed inception to June 2020.

RESULTS

Novel concepts of pathophysiology, such as the proportionate/disproportionate conceptual framework, the role of papillary muscles and left ventricular dysfunction, the impact of myocardial ischemia and revascularization, left ventricular remodeling, and the effect of restrictive annuloplasty or subvalvular procedures have been reviewed.

CONCLUSIONS

The clinical benefits associated with the use of MitraClip is more evident in patients with disproportionate FMR with greater and sustained left ventricular reverse remodeling. Importantly, in the absence of myocardial revascularization, expansion of myocardial scar tissue and non-perfused areas of ischemic myocardium occur with time, and this impact on outcomes with a longer follow-up period cannot be quantified. In advanced phases of FMR, neither mitral ring annuloplasty nor percutaneous therapies could significantly modify the established pathoanatomic alterations.

Surgical versus transcatheter mitral valve replacement in functional mitral valve regurgitation

Surgical mitral valve intervention for severe functional, or secondary mitral regurgitation is a viable option for patients deemed to be operative candidates and can be performed via traditional sternotomy or by minimally invasive techniques with similar outcomes. Transcatheter mitral valve replacement is an emerging technology with a potential role in the treatment of functional mitral valve regurgitation. A plethora of devices are currently in development and in various stages of clinical investigation. Operative approach to transcatheter mitral valve replacement varies from a percutaneous transseptal approach to a hybrid percutaneous/surgical apical approach. The Tendyne, Intrepid and Evoque systems show promising results from their early feasibility studies in treatment of patients with mitral regurgitation that were too high risk for surgery. In this review, we describe considerations for surgical and transcatheter mitral valve replacement for functional mitral valve regurgitation.

Early Structural Valve Deterioration of Tricuspid Pericardial Valve Caused by Native Valve Adhesion

Although preservation of the subvalvular apparatus affects left ventricular function and late outcome in mitral valve replacement, there are some reports of early structural valve deterioration caused by the adhesion of native valves. We report the case of a 41-year-old woman who developed early structural valve deterioration after tricuspid valve replacement caused by the adhesion of native valves. It is a rare complication, but one to consider upon observing early rising of the pressure gradient or symptoms after tricuspid valve replacement like mitral valve replacement.

The Choice of Treatment in Ischemic Mitral Regurgitation With Reduced Left Ventricular Function

BACKGROUND

Ischemic mitral regurgitation is a condition characterized by mitral insufficiency secondary to an ischemic left ventricle. Primarily, the pathology is the result of perturbation of normal regional left ventricular geometry combined with adverse remodeling. We present a comprehensive review of contemporary surgical, medical, and percutaneous treatment options for ischemic mitral regurgitation, rigorously examined by current guidelines and literature.

METHODS

We conducted a literature search of the PubMed database, Embase, and the Cochrane Library (through November 2018) for studies reporting perioperative or late mortality and echocardiographic outcomes after surgical and nonsurgical intervention for ischemic mitral regurgitation.

RESULTS

Treatment of this condition is challenging and often requires a multimodality approach. These patients usually have multiple comorbidities that may preclude surgery as a viable option. A multidisciplinary team discussion is crucial in optimizing outcomes. There are several options for treatment and management of ischemic mitral regurgitation with differing benefits and risks. Guideline-directed medical therapy for heart failure is the treatment choice for moderate and severe ischemic mitral regurgitation, with consideration of coronary revascularization, mitral valve surgery, cardiac resynchronization therapy, or a combination of these, in appropriate candidates. The use of transcatheter mitral valve therapy is considered appropriate in high-risk patients with severe ischemic mitral regurgitation, heart failure, and reduced left ventricular ejection fraction, especially in those with hemodynamic instability.

CONCLUSIONS

The role of mitral valve surgery and transcatheter mitral valve therapy continues to evolve.

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

Mitral valve repair versus replacement with preservation of the entire subvalvular apparatus

OBJECTIVE

This study aimed to evaluate the outcomes of mitral valve (MV) repair versus MV replacement with preservation of the entire subvalvular apparatus.

METHODS

We retrospectively searched our dedicated in-hospital database for patients who underwent MV surgery between 2012 and 2017.

RESULTS

A total of 82 patients were divided into a group that underwent MV replacement (n = 35) and a group that underwent MV repair (n = 47). Patients undergoing MV replacement were significantly older (p < 0.01). Mortality at 30 days was not significantly different [MV replacement: n = 1 (2.9%), MV repair: n = 0 (0%); p = 0.43]. The single case of 30-day mortality after MV replacement was due to acute aortic dissection. The total cohort did not show significant differences in long-term survival (p = 0.07). There were no cardiac-related deaths in this cohort. Postoperative left ventricular end-diastolic diameter (MV replacement: 45.4 ± 6.2 mm, MV repair: 45.6 ± 5.8 mm; p = 0.89), left ventricular end-systolic diameter (MV replacement: 29.6 ± 7.1 mm, MV repair: 29.4 ± 5.2 mm; p = 0.89), and ejection fraction (MV replacement: 59.2 ± 11.4%, MV repair: 62.0 ± 6.8%; p = 0.17) were not significantly different.

CONCLUSIONS

This study found that MV replacement had operative mortality, long-term survival, and complication rates similar to those of MV repair. There were no cardiac-related deaths in this cohort. MV replacement with preservation of the entire subvalvular apparatus does not seem to be inferior to MV repair.

Mitral Valve Repair Versus Replacement in Elderly With Degenerative Disease: Analysis of the STS Adult Cardiac Surgery Database

BACKGROUND

It has been postulated that mitral valve repair in the elderly does not confer short-term benefits over mitral valve replacement with complete preservation of the chordal apparatus. Our purpose was to test this hypothesis using data from The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD).

METHODS

Patients aged 70 years or more undergoing primary isolated elective mitral valve repair or mitral valve replacement for degenerative disease were obtained from the STS ACSD versions 2.73 and 2.81. Patients with a concomitant tricuspid procedure, atrial fibrillation surgery, or atrial septal defect/patent foramen ovale repair were included. The two treatment groups were further stratified by age in years (70 to 74, 75 to 79, and 80 or more). Adjusted 30-day mortality rates were analyzed by mitral procedure and chordal preservation strategy.

RESULTS

The study included 12,043 patients, of whom 71% underwent mitral valve repair. Observed 30-day mortality after repair was lower than after replacement (2.2% versus 4.8%, respectively; p < 0.0001). Using repair as reference, adjusted operative mortality was higher for replacement in the overall cohort (odds ratio 1.83, 95% confidence interval: 1.45 to 2.31). There was no significant difference in mortality between complete versus partial chordal preservation in repair (odds ratio 1.24, 95% confidence interval: 0.80 to 1.93). Mitral valve replacement with chordal preservation remained inferior to repair (odds ratio 1.66, 95% confidence interval: 1.28 to 2.14). The failed repair rate was 7.9%, with a 30-day mortality of 6%.

CONCLUSIONS

In patients aged 70 years or more, degenerative mitral repair was associated with lower operative mortality compared with replacement, irrespective of chordal preservation strategy. Failed repairs reduced this short-term benefit compared with chordal-sparing replacement as evidenced by the similar operative mortality on an intention to treat analysis.

Repair or replacement for severe ischemic mitral regurgitation: A meta-analysis

BACKGROUND

The best surgical option for severe ischemic mitral regurgitation (IMR) is still controversial. The aim of this study was to perform a meta-analysis to compare the clinical outcomes of mitral valve repair (MVP) with replacement (MVR).

METHODS

A literature search was conducted in PubMed, Embase, and Medline using the terms "ischemic mitral regurgitation" and "repair or annuloplasty or reconstruction" and "replacement" in the title/abstract field. The primary outcomes of interest were perioperative mortality and long-term survival. Secondary outcomes were mitral regurgitation (MR) recurrence and reoperation.

RESULTS

Of 276 studies, 13 studies met the inclusion and exclusion criteria. A total of 1993 patients were included in these studies, consisting of 1259 (63%) repair cases, and 734 (37%) replacement cases. Perioperative mortality was lower with MVP compared with MVR [OR 0.61; (95% CI, 0.43-0.87; P < .05)]. There was no difference with respect to long-term survival [HR 0.75; (95% CI, 0.52-1.09; P = .14)] and reoperation [OR 0.77; (95% CI, 0.38-1.57; P = .47)]. MVP is associated with a higher recurrence of MR [OR = 4.09; (95% CI, 1.82-9.19; P < .001)].

CONCLUSION

MVP is associated with a lower perioperative mortality but a higher recurrence of MR compared with MVR for severe IMR. No differences were found with respect to long-term survival and reoperation.

Total Chordal Sparing Mitral Valve Replacement in Rheumatic Disease: A Word of Caution

Total chordal preservation is the standard for mitral valve replacement to maintain long-term left ventricular geometry. Whereas it is appropriate for functional and degenerative mitral regurgitation, the role of chordal sparing in rheumatic valve disease is less well understood, with limited evidence supporting total chordal sparing. Inasmuch as this autoimmune disease affects the subvalvular apparatus in addition to the leaflets, it can be expected to continue after surgical repair. Here we present 2 patients who experienced adverse events associated with total chordal sparing mitral replacement as a result of disease progression with rapid fibrous growth causing inflow obstruction and early prosthetic valve failure.

Effect of Chordal Preservation on Left Ventricular Function

Chordopapillary apparatus preservation was compared with valve-excising mitral valve replacement in a retrospective analysis of 360 patients, of whom 98 had total or partial chordal preservation and 262 had the conventional operation. No significant differences were seen in age, sex, pathology, crossclamp or cardiopulmonary bypass times between the 3 groups. Left ventricular fractional shortening decreased significantly in patients whose valves had been excised completely, whereas it remained unchanged in patients with either partial or total chordal conservation. There was a survival benefit for patients undergoing leaflet preservation (92% vs. 80% for conventional excision at 5 years; p = 0.001). Chordal preservation during valve replacement for mitral valve disease improves survival, enhances functional status, preserves left ventricular geometry and function, and improves overall cardiac performance. Preservation of the posterior leaflet alone offers excellent results that are comparable to those of patients with total chordal preservation.

Two-Year Outcomes of Surgical Treatment of Severe Ischemic Mitral Regurgitation

BACKGROUND

In a randomized trial comparing mitral-valve repair with mitral-valve replacement in patients with severe ischemic mitral regurgitation, we found no significant difference in the left ventricular end-systolic volume index (LVESVI), survival, or adverse events at 1 year after surgery. However, patients in the repair group had significantly more recurrences of moderate or severe mitral regurgitation. We now report the 2-year outcomes of this trial.

METHODS

We randomly assigned 251 patients to mitral-valve repair or replacement. Patients were followed for 2 years, and clinical and echocardiographic outcomes were assessed.

RESULTS

Among surviving patients, the mean (±SD) 2-year LVESVI was 52.6±27.7 ml per square meter of body-surface area with mitral-valve repair and 60.6±39.0 ml per square meter with mitral-valve replacement (mean changes from baseline, -9.0 ml per square meter and -6.5 ml per square meter, respectively). Two-year mortality was 19.0% in the repair group and 23.2% in the replacement group (hazard ratio in the repair group, 0.79; 95% confidence interval, 0.46 to 1.35; P=0.39). The rank-based assessment of LVESVI at 2 years (incorporating deaths) showed no significant between-group difference (z score=-1.32, P=0.19). The rate of recurrence of moderate or severe mitral regurgitation over 2 years was higher in the repair group than in the replacement group (58.8% vs. 3.8%, P<0.001). There were no significant between-group differences in rates of serious adverse events and overall readmissions, but patients in the repair group had more serious adverse events related to heart failure (P=0.05) and cardiovascular readmissions (P=0.01). On the Minnesota Living with Heart Failure questionnaire, there was a trend toward greater improvement in the replacement group (P=0.07).

CONCLUSIONS

In patients undergoing mitral-valve repair or replacement for severe ischemic mitral regurgitation, we observed no significant between-group difference in left ventricular reverse remodeling or survival at 2 years. Mitral regurgitation recurred more frequently in the repair group, resulting in more heart-failure-related adverse events and cardiovascular admissions. (Funded by the National Institutes of Health and Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00807040.).

A meta-analysis of mitral valve repair versus replacement for ischemic mitral regurgitation

BACKGROUND

The development of ischemic mitral regurgitation (IMR) portends a poor prognosis and is associated with adverse long-term outcomes. Although both mitral valve repair (MVr) and mitral valve replacement (MVR) have been performed in the surgical management of IMR, there remains uncertainty regarding the optimal approach. The aim of the present study was to meta-analyze these two procedures, with mortality as the primary endpoint.

METHODS

Seven databases were systematically searched for studies reporting peri-operative or late mortality following MVr and MVR for IMR. Data were independently extracted by two reviewers and meta-analyzed according to pre-defined study selection criteria and clinical endpoints.

RESULTS

Overall, 22 observational studies (n=3,815 patients) and one randomized controlled trial (n=251) were included. Meta-analysis demonstrated significantly reduced peri-operative mortality [relative risk (RR) 0.61; 95% confidence intervals (CI), 0.47-0.77; I(2)=0%; P<0.001] and late mortality (RR, 0.78; 95% CI, 0.67-0.92; I(2)=0%; P=0.002) following MVr. This finding was more pronounced in studies with longer follow-up beyond 3 years. At latest follow-up, recurrence of at least moderate mitral regurgitation (MR) was higher following MVr (RR, 5.21; 95% CI, 2.66-10.22; I(2)=46%; P<0.001) but the incidence of mitral valve re-operations were similar.

CONCLUSIONS

In the present meta-analysis, MVr was associated with reduced peri-operative and late mortality compared to MVR, despite an increased recurrence of at least moderate MR at follow-up. However, these findings must be considered within the context of the differing patient characteristics that may affect allocation to MVr or MVR. Larger prospective studies are warranted to further compare long-term survival and freedom from re-intervention.

Long-term survival after mitral valve surgery for post-myocardial infarction papillary muscle rupture

BACKGROUND

Papillary muscle rupture (PMR) is a rare, but dramatic mechanical complication of myocardial infarction (MI), which can lead to rapid clinical deterioration and death. Immediate surgical intervention is considered the optimal and most rational treatment, despite high risks. In this study we sought to identify overall long-term survival and its predictors for patients who underwent mitral valve surgery for post-MI PMR.

METHODS

Fifty consecutive patients (mean age 64.7±10.8 years) underwent mitral valve repair (n=10) or replacement (n=40) for post-MI PMR from January 1990 through May 2014. Clinical data, echocardiographic data, catheterization data, and surgical data were stored in a dedicated database. Follow-up was obtained in June of 2014; mean follow-up was 7.1±6.8 years (range 0.0-22.2 years). Univariate and multivariate Cox proportional hazard regression analyses were performed to identify predictors of long-term survival. Kaplan-Meier curves were compared with the log-rank test.

RESULTS

Kaplan-Meier cumulative survival at 1, 5, 10, 15, and 20 years was 71.9±6.4%, 65.1±6.9%, 49.5±7.6%, 36.1±8.0% and 23.7±9.2%, respectively. Univariate and multivariate analyses revealed logistic EuroSCORE≥40% and EuroSCORE II≥25% as strong independent predictors of a lower overall long-term survival. After removal of the EuroSCOREs from the model, preoperative inotropic drug support and mitral valve replacement (MVR) without (partial or complete) preservation of the subvalvular apparatus were independent predictors of a lower overall long-term survival.

CONCLUSIONS

Logistic EuroSCORE≥40%, EuroSCORE II≥25%, preoperative inotropic drug support and MVR without (partial or complete) preservation of the subvalvular apparatus are strong independent predictors of a lower overall long-term survival in patients undergoing mitral valve surgery for post-MI PMR. Whenever possible, the subvalvular apparatus should be preserved in these patients.

Bioprosthetic mitral valve dysfunction due to native valve preserving procedure

Mitral valve replacement with preservation of the mitral leaflets and subvalvular apparatus is considered to maintain left ventricular geometry and function and reduce the risk of myocardial rupture. However, the routine use of this technique may lead to early complications such as left ventricular outflow tract obstruction and even mitral inflow obstruction, requiring reoperation. We describe a rare case of bioprosthetic mitral valve dysfunction caused by a native valve preserving procedure.

Papillary muscle repositioning as a subvalvular apparatus preservation technique in mitral stenosis patients with normal left ventricular systolic function

Subvalvular apparatus preservation is an important concept in mitral valve replacement (MVR) surgery that is performed to remedy mitral regurgitation. In this study, we sought to determine the effects of papillary muscle repositioning (PMR) on clinical outcomes and echocardiographic left ventricular function in rheumatic mitral stenosis patients who had normal left ventricular systolic function. We prospectively assigned 115 patients who were scheduled for MVR surgery with mechanical prosthesis to either PMR or MVR-only groups. Functional class and echocardiographic variables were evaluated at baseline and at early and late postoperative follow-up examinations. All values were compared between the 2 groups. The PMR group consisted of 48 patients and the MVR-only group of 67 patients. The 2 groups' baseline characteristics and surgery-related factors (including perioperative mortality) were similar. During the 18-month follow-up, all echocardiographic variables showed a consistent improvement in the PMR group; the mean left ventricular ejection fraction deteriorated significantly in the MVR-only group. Comparison during follow-up of the magnitude of longitudinal changes revealed that decreases in left ventricular end-diastolic and end-systolic diameters and in left ventricular sphericity indices, and increases in left ventricular ejection fractions, were significantly higher in the PMR group than in the MVR-only group. This study suggests that, in patients with rheumatic mitral stenosis and preserved left ventricular systolic function, the addition of papillary muscle repositioning to valve replacement with a mechanical prosthesis improves left ventricular dimensions, ejection fraction, and sphericity index at the 18-month follow-up with no substantial undesirable effect on the surgery-related factors.

Importance of preservation of chordal apparatus in mitral valve replacement

Mitral valve replacement often involves disruption of the chordal apparatus with disturbance of the annulo-papillary continuity. This results in significant downgrading of ventricular function. Analyzes various reports to accurately assess the advantages of chordal preservation. This review briefly briefly reviews the surgical techniques. The advantages of chordal preservation are analyzed, with particular emphasis on the technical difficulties and potential complications involved.

Minimally invasive fibrillating mitral valve replacement for patients with advanced cardiomyopathy: a safe and effective approach to treat a complex problem

OBJECTIVE

The optimal management of mitral regurgitation (MR) in patients with cardiomyopathy has been controversial. Minimally invasive fibrillating mitral valve replacement (mini-MVR) might limit postoperative morbidity and mortality by minimizing recurrent MR. We hypothesized that mini-MVR with complete chordal sparing would offer low mortality and halt left ventricular (LV) remodeling in patients with severe cardiomyopathy and severe MR.

METHODS

From January 2006 to August 2009, 65 patients with an LV ejection fraction (LVEF) of ≤35% underwent mini-MVR. The demographic, echocardiographic, and clinical outcomes were analyzed.

RESULTS

The operative mortality compared with the Society of Thoracic Surgeons-predicted mortality was 6.2% versus 6.6%. It was 5.6% versus 7.4% for patients with an LVEF of ≤20% and 8.3% versus 17.9% among patients with a Society of Thoracic Surgeons-predicted mortality of ≥10%. At a median follow-up of 17 months, no recurrent MR or change in the LV dimensions or LVEF had developed, but the right ventricular systolic pressure had decreased (P=.02). At the first postoperative visit and latest follow-up visit, the New York Heart Association class had decreased from 3.0±0.6 to 1.7±0.7 and 2.0±1.0, respectively (P<.0001 for both). Patients with an LVEF of ≤20% and LV end-diastolic diameter of ≥6.5 cm were more likely to meet a composite of death, transplantation, or LV assist device insertion (P=.046).

CONCLUSIONS

Our results have shown that mini-MVR is safe in patients with advanced cardiomyopathy and resulted in no recurrent MR, stabilization of the LVEF and LV dimensions, and a decrease in right ventricular systolic pressure. This mini-MVR technique can be used to address severe MR in patients with advanced cardiomyopathy.

[A rare case of two mechanisms of prosthetic valve dysfunction in the same patient]

Prosthetic valve dysfunction is a significant clinical event. Determining its etiological mechanism and severity can be difficult. The authors present the case of a 50-year-old man, with two mechanical valve prostheses in aortic and mitral positions, hospitalized for decompensated heart failure. He had a long history of rheumatic multivalvular disease and had undergone three heart surgeries. On admission, investigation led to a diagnosis of severe dysfunction of both mechanical prostheses with different etiologies and mechanisms: pannus formation in the prosthetic aortic valve and intermittent dysfunction of the mitral prosthesis due to interference of a ruptured chorda tendinea in closure of the disks. The patient was reoperated, leading to significant improvement in functional class.

Predictors of left ventricular remodeling after surgical repair or replacement for pure severe mitral regurgitation caused by leaflet prolapse

We sought to determine whether preoperative baseline echocardiographic analysis and the type of surgical procedure are predictive of the magnitude and timing of postoperative left ventricular (LV) remodeling in patients undergoing valve surgery for pure severe mitral regurgitation (MR) secondary to leaflet prolapse. Seventy-two consecutive patients without coronary artery disease undergoing valve repair (MVr; n = 42) or replacement (MVR; n = 30) underwent preoperative, early (1 to 2 days) and late postoperative (4.5 ± 2.5 and 18 ± 8.0 months) echocardiography. Patients were categorized according to their baseline LV ejection fraction (EF) (Group 1: EF ≥60%, Group 2: EF = 50% to 59%, Group 3: EF <50%). Preservation of the subvalvular apparatus was achieved in most patients undergoing MV replacement (87%). Over a median follow-up period of 450 days, LVEF changed as follows: Group 1: 63% ± 2% to 60% ± 3% (p <0.0001); Group 2: 55% ± 3% to 52% ± 6% (p <0.0001); Group 3: 43% ± 4% to 42% ± 5% (p <0.01). Two-thirds of the observed changes in LV diameters and volumes occurred in the first 6 months. Preoperative LVEF was the best predictor of postoperative LVEF ≥60% (odds ratio 1.50, 95% confidence interval, 1.25 to 1.97; p <0.0001). No significant difference was found in LV remodeling parameters between patients undergoing MVr and MVR. In conclusion, patients with pure severe MR due to valve prolapse LVEF remained normal after surgery only in patients with baseline LVEF ≥60%. MVR with subvalvular preservation was associated with similar postoperative remodeling as MVr.

Complete Preservation of the Mitral Valve Apparatus during Mitral Valve Replacement for Rheumatic Mitral Regurgitation in Patients with an Enlarged Left Ventricular Chamber

<p><b>Background and Aims:</b> The merits of retaining the subvalvular apparatus during mitral valve replacement (MVR) for chronic mitral regurgitation have been demonstrated in clinical investigations. This study was to investigate the feasibility of total preservation of the leaflet and subvalvular apparatus at the native anatomic position during MVR in a rheumatic population with enlarged left ventricular chamber.</p><p><b>Material and Methods:</b> The techniques of valvular apparatus preservation used during MVR with or without aortic valve replacement were investigated in 128 patients with an enlarged left ventricular chamber suffering from rheumatic mitral regurgitation between October 2003 and December 2007. Seventy patients had the anterior leaflet and subvalvular apparatus excised but the posterior leaflet and subvlvular apparatus preserved during the mitral valve replacement (P-MVR group), and 58 patients had the anterior and posterior mitral leaflets and the subvalvalur apparatus completely preserved at the native anatomical position during the mitral valve replacement (C-MVR group). Echocardiography was performed preoperatively, at discharge, and after 3 months, 1 year, and 3 years to determine the left ventricular dimensions and function.</p><p><b>Results:</b> There were 2 cases (3.4%) of early death in the C-MVR group, and there were 4 cases (5.7%) of early death in the P-MVR group. There were 3 cases of late death 1 year after surgery, of which 1 case in the C-MVR group was caused by congestive heart failure and the other 2 cases in the P-MVR group were due to sudden death. Both groups exhibited significant improvement (<i>P <</i> .05) in left ventricular function instantly and late postoperatively. The reduction of the left ventricular end-diastolic diameter was more significant in the C-MVR group as compared to the P-MVR group (<i>P <</i> .05). A statistically significant increase in fractional shortening (FS) occurred in the C-MVR group compared to the P-MVR group.</p><p><b>Conclusion:</b> This study shows that complete mitral leaflet preservation at the native anatomical position during MVR is feasible in rheumatic patients with an enlarged left ventricular chamber and confers significant short-term and long-term advantages by preserving left ventricular function and geometry. Therefore, it is a safe, simple, and effective surgical technique and should be individualized during clinical use.</p>

Changes in left ventricular morphology and function after mitral valve surgery

Degenerative mitral valve disease is the leading cause of mitral regurgitation in North America. Surgical intervention has hinged on the symptoms and ventricular changes that develop as compensatory ventricular remodeling occurs. In the present study, we sought to characterize the temporal response of left ventricular (LV) morphology and function to mitral valve surgery for degenerative disease and to identify the preoperative factors that influence reverse remodeling. From 1986 to 2007, 2,778 patients with isolated degenerative mitral valve disease underwent valve repair (n = 2,607 [94%]) or replacement (n = 171 [6%]) and had ≥1 postoperative transthoracic echocardiogram; 5,336 transthoracic echocardiograms were available for analysis. Multivariate longitudinal repeated-measures analysis was performed to identify the factors associated with reverse remodeling. The LV dimensions decreased in the first year after surgery (end-diastolic from 5.7 ± 0.80 to 4.9 ± 1.4 cm; end-systolic from 3.4 ± 0.71 to 3.1 ± 1.4 cm). The LV mass index decreased from 139 ± 44 to 112 ± 73 g/m(2). The reduction in LV hypertrophy was less pronounced in patients with greater preoperative left heart enlargement (p <0.0001) and a greater preoperative LV mass (p <0.0001). The postoperative LV ejection fraction initially decreased from 58 ± 7.0% to 53 ± 20%, increased slightly during the first postoperative year, and was negatively influenced by preoperative heart failure symptoms (p <0.0001) and a lower preoperative LV ejection fraction (p <0.0001). The risk-adjusted response of LV morphology and function to valve repair and replacement was similar (p >0.2). In conclusion, a positive response toward normalization of LV morphology and function after mitral valve surgery is greatest in the first year. The best response occurs when surgery is performed before left heart dilation, LV hypertrophy, or LV dysfunction develop.

Triple left ventricular outflow tract obstruction

A 59-year-old man had, over a period of 5 years, three different clinical scenarios which led to dynamic left ventricular outflow tract obstruction (LVOTO). Initially, this man who suffered from hypertrophic cardiomyopathy presented with asymmetric septal hypertrophy and systolic anterior motion (SAM) of the anterior mitral leaflet, along with mitral regurgitation. He was treated by septal myectomy and mitral valve repair with insertion of an artificial mitral ring. Several years later, he presented with severe LVOTO, this time related to the anteriorly displaced mitral coaptation site and the prosthetic ring. The ring and the anterior mitral leaflet were resected and a prosthetic mitral valve implanted. Several years later, the patient presented with LVOTO for a third time. It was now SAM of the remaining posterior leaflet that was responsible for the LVOTO.

Resuspension of the uninfarcted papillary muscle at the time of mitral valve replacement in a patient with post myocardial infarction papillary muscle rupture

A 60-year-old woman was referred to the Department of Cardiovascular Surgery of Social Insurance Chukyo Hospital for the rupture of a postinfarction papillary muscle. The rupture was in the posterior part of the anterolateral papillary muscle, in which more than two-thirds of its posterior leaflet was prolapsed. Mortality from the surgical repair of a papillary muscle rupture is quite high. For this case, we resuspended the uninfarcted papillary muscle heads case to preserve mitral ventricular continuity because the mitral annulus was quite small and more than two-thirds of the posterior leaflet were detached from the papillary muscle. The post-operative course of the patient was uneventful. Resuspension of uninfarcted papillary muscle is a useful technique to repair a rupture in the papillary muscle.