Functional mitral regurgitation: an overview for surgical management framework

Recent Developments in Ventricular Assist Device Therapy

The evolution of left ventricular assist devices (LVADs) from large, pulsatile systems to compact, continuous-flow pumps has significantly improved implantation outcomes and patient mobility. Minimally invasive surgical techniques have emerged that offer reduced morbidity and enhanced recovery for LVAD recipients. Innovations in wireless power transfer technologies aim to mitigate driveline-related complications, enhancing patient safety and quality of life. Pediatric ventricular assist devices (VADs) remain a critical unmet need; challenges in developing pediatric VADs include device sizing and managing congenital heart disease. Advances in LVAD technology adapted for use in right ventricular assist devices (RVADs) make possible the effective management of right ventricular failure in patients with acute cardiac conditions or congenital heart defects. To address disparities in mechanical circulatory support (MCS) access, cost-effective VAD designs have been developed internationally. The Vitalmex device from Mexico City combines pulsatile-flow technology with a paracorporeal design, utilizing cost-effective materials like silicone-elastic and titanium, and features a reusable pump housing to minimize manufacturing and operational costs. Romanian researchers have used advanced mathematical modeling and three-dimensional (3D) printing to produce a rim-driven, hubless axial-flow pump, achieving efficient blood flow with a compact design that includes a wireless power supply to reduce infection risk. In conclusion, MCS continues to advance with technological innovation and global collaboration. Ongoing efforts are essential to optimize outcomes, expand indications, and improve access to life-saving therapies worldwide.

Transcatheter Approaches to Atrial Functional Mitral Regurgitation: How Far Have We Come?

Functional mitral regurgitation (MR) is associated with increased cardiovascular morbidity and mortality and over the past decade, the diagnosis of atrial functional mitral regurgitation (aFMR) has been increasingly observed in the elderly, especially in those with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). Annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering distinguish the pathophysiology of aFMR from the one of ventricular origin. However, no consensus provides recommendations regarding the differential diagnosis and the subsequent management of aFMR. The advent of transcatheter mitral valve repair has paved the way for various treatments including edge-to-edge repair (TEER), mitral annuloplasty, and replacement, with optimistic results on short-medium-term outcome provided by preliminary studies. In parallel, rhythm control of AF for paroxysmal and persistent types, should be pursued to induce reverse remodeling and restoring the normal leaflet coaptation. In this setting, catheter ablation aiming for electrical isolation of the pulmonary veins is the most widely recognized and effective strategy for maintaining sinus rhythm. Nevertheless, arrhythmia-free survival is lower in patients with persistent and long-term persistent AF, leading to the adoption of hybrid strategies combining transcatheter endocardial ablation and thoracoscopic epicardial surgical ablation. This review provides an update on the diagnosis and treatment of aFMR, focusing on available transcatheter approaches that can be performed in the catheterization lab and electrophysiology lab.

Comparing surgical techniques and results of secondary ischemic mitral regurgitation: a state-of-the-art literature review

Background and Objective

Surgery for mitral valve disease is a developing area with a wide range of surgical options. There is growing evidence on the best approach for secondary ischemic mitral regurgitation (SIMR) when the pathology is within the ventricle. The goal of this literature review is to provide a comprehensive comparison of surgical treatments for SIMR.

Methods

The initial screening process included PubMed, Medline and Embase to identify randomized controlled trials, propensity-matched observational series, meta-analyses and unmatched observational series. The terms used were 'mitral valve disease', 'secondary mitral regurgitation', 'secondary ischemic mitral regurgitation', 'functional mitral regurgitation', 'restrictive mitral annuloplasty', 'subvalvular repair', 'Trans Catheter Edge to Edge Repair and echocardiography coupled with secondary mitral regurgitation', 'secondary ischemic mitral regurgitation', and 'functional mitral regurgitation'. Six strategies have been identified for treating SIMR. These include mitral valve replacement (MVR), restrictive mitral annuloplasty, surgical revascularisation (with and without mitral annuloplasty), subvalvular procedures [papillary muscle (PM) approximation, PM relocation, ring and string procedure], procedures directly targeting the mitral valve (edge-to-edge repair and anterior leaflet enlargement), and transcatheter heart valve therapy.

Key Content and Findings

There is a deficiency of robust empirical data to enable meaningful comparisons between MVR, mitral valve repair (including subvalvular repair), and transcatheter mitral valve procedure. This review will definitively analyze the current outcomes of transcatheter mitral valve procedure using the edge-to-edge mitral valve repair technique and standard surgical mitral valve procedures in patients with secondary mitral regurgitation (MR). In addition, the seminar highlights the role of left ventricular assist devices in managing SIMR. It discusses the advantages and limitations of each intervention.

Conclusions

Currently, there is no consensus on the optimal management strategy for patients with SIMR. Therefore, a multidisciplinary cardiac team should manage patients with secondary MR to ensure the best outcome by matching the ideal intervention with the patient.

Impact of transcatheter edge to edge repair in functional mitral regurgitation and cardiac resynchronization-therapy nonresponders

BACKGROUND

Despite optimal medical therapy and cardiac resynchronization therapy (CRT), significant functional mitral regurgitation (MR) persisted in 30% of the patients and labeled as CRT nonresponders.

AIMS

We sought to study the impact of transcatheter edge-to-edge repair (TEER) in patients with symptomatic grade III and IV functional MR despite CRT.

METHODS

A retrospective analysis was conducted of all patients who had prior CRT for at least 6 months and underwent TEER for significant residual functional MR (grade ≥3) and symptomatic heart failure (HF) at our institution. The primary outcomes were the change in New York Heart Association classification (NYHA), MR grade, echo parameters, and NT-ProBNP from baseline to 1-year post-procedure.

RESULTS

A total of 28 patients were identified, mean age of 73 ± 6.7 years and 89% males. Procedure success was achieved in all patients. At 1-year follow-up, patients had lower MR grade (median 2, IQR 1 [1,2] vs. 4, IQR 1 [3,4]; p < 0.001), NYHA class (median 2, IQR 1 [2,3] vs. 3, IQR 1 [3,4]; p < 0.001), and NT-ProBNP (7658 ± 11322 vs. 3760 ± 4431; p = 0.035) compared to before the TEER procedure. The left ventricular end-diastolic volume (255 ± 59 vs. 244 ± 66 mm; p = 0.016) and the right ventricular systolic pressure (52 ± 14 mmHg vs. 37 ± 13 mmHg, <0.001) decreased.

CONCLUSION

Patients who remain symptomatic after CRT with severe functional MR had improved functional status and MR grade at 1-year following TEER. There was a signal toward reverse remodeling.

Atrial functional mitral regurgitation in cardiology and cardiac surgery

Functional or secondary mitral regurgitation (MR) is a clear and present danger to cardiovascular health, with heightened morbidity and mortality rates. Secondary MR is caused by an imbalance between two sets of forces. There are two forces at play here. One keeps the mitral leaflets tethered, while the other closes them. The evidence clearly shows inadequate coaptation. Functional MR (FMR) is the typical form of MR. It is almost always caused by dysfunction and alterations of the left ventricle (LV) geometry. It occurs in both ischemic and non-ischemic disease states. Atrial FMR (AFMR) is a disease that has only recently come to be acknowledged. This phenomenon arises when mitral annular enlargement is caused by left atrial enlargement. This preserves the geometry and function of the LV. AFMR is most frequently encountered in individuals with chronic atrial fibrillation or heart failure, in whom a normal ejection fraction is present. Published studies and ongoing research vary in their definition of AFMR, but there is no doubt that AFMR exists. This review definitively explains the pathophysiology of AFMR and demonstrates the necessity of a common working standard for the definition of AFMR. This is essential to warrant cohesiveness in the data reported and to drive forward the much-needed research into the outcomes and treatment strategies in this critical field. A number of high-quality studies have demonstrated that restrictive mitral annuloplasty and transcatheter procedure based on edge-to-edge repair are effective in reducing MR and alleviating symptoms. The pathophysiology, echocardiographic diagnosis, and treatment of AFMR are thoroughly reviewed in this comprehensive review.

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

Assessing emerging causes of mitral regurgitation: atrial functional mitral regurgitation

Functional or secondary mitral regurgitation is linked to increased cardiovascular morbidity and mortality. From a mechanical perspective, secondary mitral regurgitation occurs due to an imbalance between the forces that tether the mitral leaflets and those that close them. This results in incomplete coaptation. Most commonly, functional mitral regurgitation, which occurs in both ischaemic and non-ischaemic disease states, is usually caused by dysfunction and changes in the left ventricle. Atrial functional mitral regurgitation (AFMR) is a disease state that has been more recently recognized. It occurs when mitral annular enlargement is associated with left atrial dilatation, preserving left ventricular geometry and function. AFMR is typically seen in patients with chronic atrial fibrillation or heart failure who have a conserved ejection fraction. Published reports and ongoing investigations vary in how they define AFMR. This publication examines the pathophysiology of AFMR and highlights the importance of having a common working standard for the definition of AFMR to ensure consistency in the data reported and to drive forward the much needed research into the outcomes and treatment strategies in this area. Several studies have reported that restrictive annuloplasty and transcatheter edge-to-edge repair can reduce mitral regurgitation and improve symptoms. This narrative review will explore the pathophysiology, echocardiographic diagnosis and treatment of AFMR.

Mitral Valve Transcatheter Edge-to-Edge Repair Volumes and Trends

Background

Despite an association between operator volumes and procedural success, there remains an incomplete understanding of the contemporary utilization and procedural volumes for mitral valve transcatheter edge-to-edge repair (MTEER). We aimed to identify annual operator procedural volumes, temporal trends, and geographic variability for MTEER among Medicare patients in the United States (US).

Methods

We queried the National Medicare Provider Utilization and Payment Database for a CPT code (33418) specific for MitraClip device from 2015 through 2019. We analyzed annual operator procedural volumes and incidence and identified longitudinal and geographic trends in MTEER utilization.

Results

From 2015 through 2019, a total of 27,034 MTEER procedures were performed among Medicare patients in the US. The nationwide incidence increased from 6.2 per 100,000 patients in 2015 to 23.8 per 100,000 patients in 2019, a 283% increase over the study period (Ptrend < 0.001). The incidence of MTEER by state varied by nearly 900% (range 5.5 to 54.9 per 100,000 person-years). In 2019, the mean annual MTEER operator annual volume was 9.1 MTEER procedures and had grown from 6.2 per year in 2015.

Conclusions

In this nationwide study of Medicare beneficiaries in the United States, we identified a significant and sustained increase in the utilization of MTEER devices and operators and growth in annual procedural volumes from 2015 through 2019 with considerable variability in utilization by state. Further studies are needed to understand the clinical impact of variability in utilization and the optimal procedural volumes to ensure high efficacy outcomes and maintain critical access to MTEER therapies.

Isolated annuloplasty in elderly patients with secondary mitral valve regurgitation: short- and long-term outcomes with a less invasive approach

Background

Long-term outcomes of elderly and frail patients with secondary mitral valve regurgitation (MR) are inconclusive. Especially in patients with co-morbidities such as atherosclerosis who are suffering from heart failure, optimal medical therapy (OMT) is the preferred therapy relative to surgical or percutaneous interventions. It remains challenging to identify the most successful therapy to improve symptoms and increase life expectancy. To reduce surgical trauma for these patients, minimally invasive mitral valve surgery (MIMVS) was developed; this has shown promising medium-term results, but there is still a lack of evidence regarding long-term results. The aim of this investigation was to describe the long-term outcomes of less invasive mitral valve surgery (MVS) in elderly patients.

Methods

In this longitudinal retrospective analysis, 67 patients (aged ≥70 years) with secondary MR who underwent MV repair ± tricuspid valve repair (TVR) were identified. MVS was performed via minithoracotomy (MT) in most cases (n = 54); in patients with contraindications for MIMVS, partial upper sternotomy (PS) was the preferred route for surgical access (n = 13). The appropriate access route was chosen according to the patient's clinical condition and comorbidities. We analyzed reoperation-free long-term survival, combined operative success (lack of residual MR, conversion to MV replacement, or larger thoracic incisions), and perioperative safety (at 30 days: mortality, re-thoracotomy, ECMO, pacemaker implantation, dialysis, longer ventilation, stroke, myocardial infarction). In a subgroup analysis, we compared long-term survival in MVS patients with and without TVR.

Results

The median age of patients (62.7% female) was 74 years (interquartile range: 72-76 years), with a median EuroSCORE2 of 2.8% (1.5%-4.6%) and N-terminal pro-brain natriuretic peptide plasma levels of 1,434 ng/L (1035-2149 ng/L). The median follow-up period was 5.6 years (2.7-8.5 years). The reoperation-free long-term survival rate up to 10 years was 66.2%. Combined operative success and perioperative safety were achieved in 94% and 76% of patients, respectively. Additional TVR was performed in 56.7% of patients, without any significant difference in survival rates compared to the group without TVR (p = 0.417; HR 1.473, 95% CI 0.578-3.757).

Conclusion

Less invasive MV repair for secondary MR shows excellent operative success and safety in selected patients. Freedom from significant MR and from the need for reoperation indicates long-lasting efficacy. These results should be considered in heart team discussions regarding allocation of patients to surgical mitral procedures.

Computational Modeling of the Subject-Specific Effects of Annuloplasty Ring Sizing on the Mitral Valve to Repair Functional Mitral Regurgitation

Surgical repair of functional mitral regurgitation (FMR) that occurs in nearly 60% of heart failure (HF) patients is currently performed with undersizing mitral annuloplasty (UMA), which lacks short- and long-term durability. Heterogeneity in valve geometry makes tailoring this repair to each patient challenging, and predictive models that can help with planning this surgery are lacking. In this study, we present a 3D echo-derived computational model, to enable subject-specific, pre-surgical planning of the repair. Three computational models of the mitral valve were created from 3D echo data obtained in three pigs with HF and FMR. An annuloplasty ring model in seven sizes was created, each ring was deployed, and post-repair valve closure was simulated. The results indicate that large annuloplasty rings (> 32 mm) were not effective in eliminating regurgitant gaps nor in restoring leaflet coaptation or reducing leaflet stresses and chordal tension. Smaller rings (≤ 32 mm) restored better systolic valve closure in all investigated cases,but excessive valve tethering and restricted motion of the leaflets were still present. This computational study demonstrates that for effective correction of FMR, the extent of annular reduction differs between subjects, and overly reducing the annulus has deleterious effects on the valve.

Mitral Interventions in Heart Failure

Patients with heart failure with reduced ejection fraction who have secondary mitral regurgitation (SMR) have poorer outcomes and quality of life than those without SMR. Guideline-directed medical therapy is the cornerstone of SMR treatment. Careful evaluation of landmark trials using mitral transcatheter edge-to-edge repair in SMR has led to an improved understanding of who will benefit from percutaneous interventions with emphasis on a multidisciplinary approach. The success with mitral transcatheter edge-to-edge repair in SMR has also spurred the evaluation of its role in populations that were not initially studied, such as end-stage heart failure and cardiogenic shock. A spectrum of transcatheter devices in development and clinical trials promise to further provide a growing array of management options for heart failure with reduced ejection fraction patients with symptomatic SMR.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

Distinctive Signs of Disease as Deterrents for the Endothelial Function: A Systematic Review

Endothelial integrity plays a major role in homeostasis and is responsive to the numerous endogenous factors released. While its functional role in vascular tone is well described, its role in the pathophysiology of cardiovascular disease is of interest as a potential therapeutic target. We performed a systematic review to provide an overview of new therapeutic and diagnostic targets for the treatment of coronary artery disease related to endothelial dysfunction. Databases of PubMed, Ovid's version of MEDLINE, and EMBASE were interrogated with appropriate search terms. Inclusion criteria have been met by 28 studies that were included in the final systematic review. We identified inflammation, pulmonary hypertension, diabetes mellitus and Fabry disease as pathophysiological mechanisms and explored the therapeutic options related to these conditions including medications such as Canakinumab. Endothelial dysfunction has a key role in several different pathophysiological processes which can be targeted for therapeutic options. Ongoing research should be targeted at making the transition to clinical practice. Further research is also needed on understanding the amelioration of endothelial dysfunction with the use of cardiovascular medications.

Pathophysiology and management of valvular disease in patients with destination left ventricular assist devices

Over the last two decades, implantable continuous flow left ventricular assist devices (LVAD) have proven to be invaluable tools for the management of selected advanced heart failure patients, improving patient longevity and quality of life. The presence of concomitant valvular pathology, including that involving the tricuspid, mitral, and aortic valve, has important implications relating to the decision to move forward with LVAD implantation. Furthermore, the presence of concomitant valvular pathology often influences the surgical strategy for LVAD implantation. Concomitant valve repair or replacement is not uncommonly required in such circumstances, which increases surgical complexity and has demonstrated prognostic implications both short and longer term following LVAD implantation. Beyond the index operation, it is also well established that certain valvular pathologies may develop or worsen over time following LVAD support. The presence of pre-existing valvular pathology or that which develops following LVAD implant is of particular importance to the destination therapy LVAD patient population. As these patients are not expected to have the opportunity for heart transplantation in the future, optimization of LVAD support including ameliorating valvular disease is critical for the maximization of patient longevity and quality of life. As collective experience has grown over time, the ability of clinicians to effectively address concomitant valvular pathology in LVAD patients has improved in the pre-implant, implant, and post-implant phase, through both medical management and procedural optimization. Nevertheless, there remains uncertainty over many facets of concomitant valvular pathology in advanced heart failure patients, and the understanding of how to best approach these conditions in the LVAD patient population continues to evolve. Herein, we present a comprehensive review of the current state of the field relating to the pathophysiology and management of valvular disease in destination LVAD patients.

Prognosis for Mitral Valve Repair Surgery in Functional Mitral Regurgitation

Purpose: Our aim was to evaluate the development of new significant mitral regurgitation and long-term survival after mitral repair surgery in functional mitral regurgitation.

Methods: A retrospective observational analysis of the recurrence of functional mitral regurgitation (ischemic and nonischemic) and global mortality during follow-up of 176 patients who underwent mitral repair surgery between 1999 and 2018 in our center was conducted.

Results: The etiology of functional mitral regurgitation was ischemic in 55.7% of cases. After surgery, mitral regurgitation was 0-I in 92.3% of cases. We conducted a long-term clinical follow-up of a mean 42.2 months and an echocardiographic follow-up of a mean 41.8 months. We observed mitral regurgitation of at least grade II in 52 patients (36.9%). Survival at 1, 3, and 5 years was 78.8%, 66.7%, and 52.3%, respectively. Predictive factors for global mortality were age (hazard ratio = 1.038, p = 0.01) and a depressed preoperative ejection fraction. After a competing risk analysis, we found the only predictive factor for the recurrence of mitral regurgitation in our series to be age (sub-hazard ratio = 1.03, 95% confidence interval = 1.01–1.06, p = 0.016).

Conclusion: Repair surgery for functional mitral regurgitation shows age as the only independent predictor of recurrence. Age and depressed ejection fraction were predictors of mortality.

Insight from International Guidelines: do We Have Satisfactory Recommendations for Secondary Mitral Regurgitation?

Both the European Society of Cardiology (ESC) and the American College of Cardiology (ACC/AHA) have recently released guidelines on the management of patients with secondary mitral regurgitation. This includes defining, classifying, and assessing the severity of secondary mitral regurgitation. These guidelines are also the first to incorporate the use of transcatheter edge-to-edge repair in decision-making based on recent studies. The review highlights the strengths and shortcomings of these studies and the applicability and generalisability of these results to assist in decision-making for the heart time. It also emphasises the importance of shared decision-making via the heart team. Echocardiography plays an important role in the assessment of these patients although these may be specifically for primary mitral insufficiency. The optimal guideline-directed medical therapy should be the first line of treatment followed by mechanical intervention. The choice of intervention is best directed by a specialist multidisciplinary team. Concomitant revascularization should be performed in a subgroup of patients with severe secondary mitral regurgitation given the role of adverse LV remodelling in propagation of the dynamic secondary MR. The guidelines need further confirmation from high-quality studies in the near future to decision-making towards either TEER, mitral valve replacement, or mitral valve repair with or without a subvalvular procedure.

The role of surgery for secondary mitral regurgitation and heart failure in the era of transcatheter mitral valve therapies

The approach to the management of mitral valve (MV) disease and heart failure (HF) has dramatically changed over the last decades. It is well recognized that severe mitral regurgitation secondary to ischemic or non-ischemic cardiomyopathy is associated with an excess risk of mortality. Understanding the impact of the surgical treatment modality on mortality outcomes has been difficult due to the broad spectrum of secondary mitral regurgitation (SMR) phenotypes and lack of randomized surgical clinical trials. Over the last 30 years, surgeons have failed to provide compelling evidence to convince the medical community of the need to treat SMR in patients with severe HF. Therefore, the surgical treatment of SMR has never gained uniform acceptance as a significant option among patients suffering from SMR. Recent evidence from randomized trials in a non-surgical eligible patients treated with transcatheter therapies, has provided a new perspective on SMR treatment. Recently published European and American guidelines confirm the key role of percutaneous treatment of SMR and in parallel, these guidelines reinforce the role of mitral valve surgery in patients who require surgical revascularization. Complex mitral valve repair combining subvalvular apparatus repair along with annuloplasty seems to be a promising approach in selected patients in selected centers. Meanwhile, mitral valve replacement has become the preferred surgical strategy in most patients with advanced heart failure and severe LV remodeling or high risk of recurrent mitral regurgitation. In this comprehensive review, we aimed to discuss the role of mitral surgery for SMR in patients with heart failure in the contemporary era and to provide a practical approach for its surgical management.

Learning from Controversy and Revisiting the Randomized Trials of Secondary Mitral Regurgitation

Until recently, conventional mitral valve surgery has been the treatment of choice even in secondary mitral regurgitation. Recent evidence, however, advocates the use of transcatheter edge-to-edge mitral valve repair (TEER) of the mitral valve. This has been reflected by the change in guidelines of the American College of Cardiology/American Heart Association. We reviewed the literature to shed light on the risks and benefits of all interventions, surgical, transcatheter and guideline-directed medical therapy. Secondary mitral regurgitation occurs due to an imbalance between closing forces and tethering forces. Given the pathology extends beyond the valve alone, treatment should be directed at restoring the geometrical shape of the left ventricle alongside the valve. Myocardial revascularization plays a pivotal role in preventing recurrence. The role of papillary muscle approximation in addition to restrictive mitral annuloplasty should be considered in a select group of patients. We also reviewed the current literature on TEERs from the COAPT and Mitra-FR trials while highlighting the concept of proportionate/disproportionate MR which may help identify which patients benefit from mitral valve restoration. Treatment of this condition will require robust randomized trials alongside the use of state-of-the-art imaging technologies available with the full complement of the multidisciplinary team to ensure the best outcomes for each patient.

Clinical Implications of Functional Mitral Regurgitation Severity in Patients with Heart Failure with Reduced Ejection Fraction (HFrEF)

Background

An estimated 64.3 million people are living with heart failure worldwide. Functional MR in chronic HFrEF reflects primarily the severity of LV dysfunction and is not related to structural alterations of the mitral valvular apparatus. FMR in patients with HFrEF independently of the etiology of HFrEF and its underlying mechanisms, contributes to progression of the symptoms of HF and is independent predictor of worse clinical outcomes.

Objective

The purpose of this study was to assess the severity of functional mitral regurgitation (FMR) and its clinical implications in patients with chronic heart failure with reduced ejection fraction (HFrEF).

Methods

We enrolled 146 consecutive adult patients with CHF with reduced ejection fraction (HFrEF) who presented to outpatient clinics. All patients underwent clinical and physical examination. Baseline examination included medical history, detailed assessment of current medication, electrocardiogram recording, transthoracic echocardiogram and comorbidities. Heart failure with reduced ejection fraction was defined in line with the new guidelines as history of HF signs and symptoms as well as a LV ejection fraction (LVEF) below 40%. Cardiovascular risk factors were recorded according to the respective guidelines. FMR was defined and graded according to the ESC/EACTS Guidelines for the management of valvular heart disease. The extent of FMR was assessed at baseline and after a median follow-up period of 4 years in 146 consecutive HFrEF patients (left ventricular ejection fraction <40%). All of the patients received the heart failure (HF) medications in agreement with 2016 and 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Major adverse cardiac events were defined as a composite of all-cause death and the need for admission for HF.

Results

A total of 146 chronic HFrEF patients (mean age of 63±11 years, 62% male, mean LVEF of 25±11%) of which 19% patients had severe FMR at baseline, with a mean EROA of 31.4±2.7 mm2 and a mean Reg Vol of 45.9±5.3 ml. There was a significant interaction between FMR and NYHA functional class in predicting death or need for hospitalization, (P < 0.0001 for the interaction term FMR NYHA III-IV). During a median follow-up period of 4.2 (IQR) 3.1-5.8) years, the primary endpoint occurred in 52 (36%) patients (21 HF admissions, and 31 deaths). There was a strong graded association between the presence and degree of FMR and risk of death or admission (P <0.0001) at 4 years follow-up period. Regarding HF therapy, 129 patients (88%) received RAAS antagonists, 17 patients (12%) received ARNI, 86 patients (59%) received beta-blockers, 75 patients (51%) were treated with MRA. 31 patients (21%) underwent cardiac resynchronization therapy (CRT) with a response rate of 64%. 24 patients (16%) underwent ICD implantation.

Conclusion

Guideline-directed medical therapy is the first-line treatment for chronic HF patients who also have FMR. After this first-line approach, surgical or MitraClip transcatheter therapy can be considered in patients with persistent severe and symptomatic FMR in order to improve symptoms, quality of life and functional status.

Ex Vivo Model of Ischemic Mitral Regurgitation and Analysis of Adjunctive Papillary Muscle Repair

Ischemic mitral regurgitation (IMR) is particularly challenging to repair with lasting durability due to the complex valvular and subvalvular pathologies resulting from left ventricular dysfunction. Ex vivo simulation is uniquely suited to quantitatively analyze the repair biomechanics, but advancements are needed to model the nuanced IMR disease state. Here we present a novel IMR model featuring a dilation device with precise dilatation control that preserves annular elasticity to enable accurate ex vivo analysis of surgical repair. Coupled with augmented papillary muscle head positioning, the enhanced heart simulator system successfully modeled IMR pre- and post-surgical intervention and enabled the analysis of adjunctive subvalvular papillary muscle repair to alleviate regurgitation recurrence. The model resulted in an increase in regurgitant fraction: 11.6 ± 1.7% to 36.1 ± 4.4% (p < 0.001). Adjunctive papillary muscle head fusion was analyzed relative to a simple restrictive ring annuloplasty repair and, while both repairs successfully eliminated regurgitation initially, the addition of the adjunctive subvalvular repair reduced regurgitation recurrence: 30.4 ± 5.7% vs. 12.5 ± 2.6% (p = 0.002). Ultimately, this system demonstrates the success of adjunctive papillary muscle head fusion in repairing IMR as well as provides a platform to optimize surgical techniques for increased repair durability.

Subannular repair for functional mitral regurgitation type IIIb in patients with ischaemic versus dilated cardiomyopathy

OBJECTIVES

Functional mitral regurgitation (FMR) is a sequel of left ventricular (LV) remodelling in heart failure patients. Relocation of both papillary muscles aims to specifically address mitral leaflet tethering to improve long-term durability of modern FMR repair. Nevertheless, the prognostic impact of the underlying cardiomyopathy on the outcome after FMR repair is unknown.

METHODS

We analysed 84 consecutive heart failure patients with severe FMR, LV ejection fraction <40%, LV end-diastolic diameter ≥55 mm and tenting height >10 mm, who underwent ring annuloplasty and simultaneous bilateral papillary muscles relocation between June 2016 and March 2019. One-year outcome of 54 patients with ischaemic cardiomyopathy ('ICM group') was prospectively compared to the remaining 30 patients with dilated cardiomyopathy ('DCM group').

RESULTS

One-year survival was similar in both groups (96% in the 'ICM group' vs 97% in the 'DCM group'; P = 0.93). Furthermore, primary composite outcome (i.e. freedom from death or mitral regurgitation ≥ 2) at 1-year postoperatively was comparable between the study groups (94%in the 'ICM group' vs 87% in the 'DCM group'; P = 0.10). LV end-diastolic diameter 1-year after surgery was significantly reduced, as compared to preoperative values, in the 'DCM group' (P = 0.018), but not in the 'ICM group' (P = 0.058). Improvement of New York Heart Association functional class and reduction of serum levels of N-terminal pro-B natriuretic peptide at 1 year was comparable in both study groups.

CONCLUSIONS

Standardized relocation of both papillary muscles to correct FMR resulted in very satisfactory in-hospital and 1-year outcomes, in both ICM and DCM. DCM patients showed similar improvement in heart failure symptoms and LV re-remodelling compared to ICM patients. Subannular repair is developing towards a valid therapeutic option in heart failure patients presenting with severe FMR.

Too much of a good thing in ischemic mitral: lessons for surgeons and cardiologists

No abstract present.

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.

Thromboembolic Complications of SARS-CoV-2 and Metabolic Derangements: Suggestions from Clinical Practice Evidence to Causative Agents

Severe Acute Respiratory Syndrome (SARS) Coronavirus (CoV)-2 is a recently identified positive sense single-strand RNA (ssRNA) β-coronavirus. The viral spike proteins infect human hosts by binding to the cellular receptor angiotensin-converting enzyme 2 (ACE2). The infection causes a systemic illness involving cell metabolism. This widespread involvement is implicated in the pathophysiology of the illness which ranges from mild to severe, requiring multi organ support, ranging from oxygen supplementation to full cardiovascular and respiratory support. Patients with multiple co-existing comorbidities are also at a higher risk. The aim of this review is to explore the exact mechanisms by which COVID-19 affects patients systemically with a primary focus on the bleeding and thrombotic complications linked with the disease. Issues surrounding the thrombotic complications following administration of the ChAdOx1 nCoV-19 (Astra-Zeneca-Oxford) vaccine have also been illustrated. Risk stratification and treatment options in these patients should be tailored according to clinical severity with input from a multidisciplinary team.

Physiological and prognostic differences between types of exercise stress echocardiography for functional mitral regurgitation

Objective

Secondary mitral regurgitation (MR) demonstrates dynamic change during exercise. This prospective observational study aimed to compare exercise stress echocardiography (ESE) where handgrip exercise (handgrip-ESE) or semisupine ergometer exercise was performed (ergometer-ESE) for patients with secondary MR.

Methods

Handgrip-ESE and symptom-limited ergometer-ESE were performed for 53 patients (median age (IQR): 68 (58–78) years; 70% male) on the same day. Baseline global longitudinal strain (GLS) was 9.2% (6.0%–14.0%) and MR volume was 20 (14–26) mL. All-cause death and cardiac hospitalisation were tracked for median 439 (101–507) days.

Results

Handgrip-ESE induced slightly but significantly greater degrees of MR increase (median one grade increase; p<0.001) than ergometer-ESE, although the changes in other parameters, including GLS (+1.1% vs −0.6%, p<0.001), were significantly smaller. Correlations between the two examinations with respect to the changes in the echocardiographic parameters were weak. Kaplan-Meier analyses revealed poor improvement in GLS during ergometer-ESE, but not the change in MR, was associated with adverse events (p=0.0065). No echocardiographic change observed during handgrip-ESE was prognostic. After adjusting for a clinical risk score, GLS changes during ergometer-ESE remained significant in predicting the adverse events (HR 0.39, p=0.03) A subgroup analysis in patients with moderate or greater MR at baseline (n=27) showed the same results as in the entire cohort.

Conclusions

The physiological and prognostic implications of handgrip-ESE and ergometer-ESE findings significantly differ in patients with left ventricular dysfunction and secondary MR. The type of exercise to be performed in ESE should be carefully selected.

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.

The Use of Radial Artery for CABG: An Update

We used the radial artery as a second target conduit for coronary artery bypass grafting since 1971. However, randomized clinical studies have demonstrated differences in clinical outcomes between the radial artery and other grafts because these trials are underpowered. As we proceed toward 50 years of experience with radial artery grafting, we examined the literature to define the best second-best target vessel for coronary artery bypass grafting. The literature was reviewed with emphasis, and a large number of randomized controlled trials, propensity-matched observational series, and meta-analyses were identified with a large patient population who received arterial conduit and saphenous vein grafts. The radial artery has been shown to be effective and safe when used as a second target conduit for coronary artery bypass grafting. Results and patency rates were superior to those for saphenous vein grafting. It has also been shown that the radial artery is a safe and effective graft as a third conduit into the territory of the artery right coronary artery. However, there is little evidence based on a few comparable series limiting the use of the gastroepiploic artery. In its fifth decade of use, we can finally deduced that the aorto-to-coronary radial bypass graft is the conduit of choice for coronary operations after the left internal thoracic artery to the left anterior descending artery.

Does the clinical effectiveness of Mitraclip compare with surgical repair for mitral regurgitation?

BACKGROUND

Surgical repair of the mitral valve has long been the established therapy for degenerative mitral regurgitation (MR). Newer transcatheter methods over the last decade, such as the MitraClip, serve to restore mitral function with reduced procedural burden and enhanced recovery. This study aims to compare the shortterm and midterm outcomes of MitraClip insertion with surgical repair for MR.

METHODS

A systematic review of the literature was conducted for studies comparing outcomes between surgical repair and MitraClip. The initial search returned 1850 titles, from which 12 studies satisfied the inclusion criteria (one randomized controlled trial and 11 retrospective studies).

RESULTS

The final analysis comprised 4219 patients (MitraClip 1210; surgery 3009). Operative mortality was not different between the groups (odds ratio [OR] = 1.63, 95% confidence interval [CI]: [0.63-4.23]; p = .317). Length of hospital stay was significantly shorter in the MitraClip group (standardized mean difference [SMD] = 0.882, 95% CI: [0.77-0.99]; p < .001) with considerable heterogeneity (I²  > 90%; p < .001). The rate of reoperation on the mitral valve was lower in the surgical group (OR = 0.392; 95% CI: [0.188-0.817]; p = .012) as was the rate of MR recurrence grade moderate or above (OR = 0.29; 95% CI: [0.19-0.46]; p < .001) during midterm follow up. Long term survival (4-5 years) was also similar between both groups (hazard ratio = 0.70; 95% CI: [0.35-1.41]; p = .323).

CONCLUSIONS

This study highlights the superior midterm durability of surgical valve repair for MR compared with the MitraClip.

The Role of False Tendons in Left Ventricular Remodeling and Secondary Mitral Regurgitation After Acute Myocardial Infarction

BACKGROUND

Left ventricular false tendons (LVFT) are common structures visualized on transthoracic echocardiography (TTE). The present study tested the hypothesis that LVFT, via a possible 'constraint' mechanism, attenuate left ventricular (LV) remodeling and secondary mitral regurgitation after acute myocardial infarction.

METHODS

Seventy-one patients admitted to the Coronary Care Unit following an ST-elevation (n = 63) or non-ST-elevation (n = 8) myocardial infarction were analyzed; 29 (41%) had LVFT, and 42 (59%) did not (no-LVFT). All had a TTE and at least 1 follow-up study after revascularization. The χ² analysis, Student's t-test, and Mann Whitney U test were used for the statistical analyses.

RESULTS

The mean age (64 vs. 66 years), left ventricular ejection fraction (LVEF) (41% vs. 39%), left ventricular end-diastolic diameter (LVEDd) index (23 mm/m² for both), and prevalence of ≥ moderate secondary/functional mitral regurgitation (MR) (17% vs. 14%) were similar between the LVFT and no-LVFT groups. At 1-year follow-up, there was no significant difference in chamber remodeling amongst the LVFT versus no-LVFT group when assessed by: 1) ≥ 10% decrease in the relative LVEF (24% vs. 26%; p = 0.83); 2) ≥ 10% increase in the LVEDd index (41% vs. 38%, p = 0.98); and, 3) ≥ 10% increase in the LV mass index (48% vs. 41%, p = 0.68). There was no difference in the prevalence of ≥ moderate secondary/functional MR (17% vs. 12%, p = 0.77). Outcomes remained similar when stratifying by LVFT morphology or ischemic territory.

CONCLUSIONS

In patients with mild to moderate LV dysfunction and normal chamber size, LVFT do not affect the development of LV remodeling or secondary/functional MR post-myocardial infarction.

Real 3D Visualization of the Circumflex Artery Surrounding the Mitral Annulus

BACKGROUND

 The circumflex coronary artery is located close to the mitral annulus. Consequently, it is not immune to iatrogenic damage during mitral valve procedures. Our objective was to visualize the circumflex artery from a surgeon's point of view, emphasizing its proximity. Furthermore, comparing it to coronary angiograms might support preoperative planning.

METHODS

 Ten adult human hearts preserved in 4% formaldehyde solution were investigated (left coronary artery injected with contrast agent). After performing coronary angiographies from LAO (left anterior oblique) 40/cranial 20, RAO (right anterior oblique) 10/cranial 40, and true lateral projections, anatomical preparations were performed. Images were captured throughout the full course of the circumflex coronary artery from multiple angles. Finally, the mean distances were measured in every 5 mm between the investigated artery and the annulus of the mitral valve.

RESULTS

 Three-dimensional model of the circumflex coronary artery and its surroundings was successfully achieved from a left atrial surgical viewpoint. The main branches were identified on the coronary angiograms. The closest distance was measured under the region of the left auricle (2.02 ± 0.69 mm; 1-3.1 mm). Afterward, the circumflex artery was observed to make a loop away from the annular region.

CONCLUSION

 Our observations show correlation with previous anatomical studies and case reports addressing iatrogenic lesions on the circumflex coronary artery. Based on all these, we could determine a "danger zone" on the vessel. The simultaneous evaluation of the anatomical preparations and the angiograms might improve the acknowledgment of this vulnerable region serving to avoid any damage to the coronary artery.

Functional mitral regurgitation

Dr. O.P. Yadava, Editor-in-Chief, IJTC, and Dr. J.L. Pomar, Former President, EACTS, discuss issues related to secondary mitral regurgitation (MR). Though it is considered a ventricular disease, mitral valve leaflets are not entirely normal. Alignment of subvalvular apparatus plays a more dominant role than annular dilatation. Early repair is preferred.

Prognostic value of mitral valve tenting area in patients with functional mitral regurgitation

OBJECTIVES

Mitral valve (MV) repair in functional mitral regurgitation is still associated with suboptimal outcomes. Our goal was to determine whether the clinical outcome following MV repair correlates with preoperative tenting parameters.

METHODS

We retrospectively identified consecutive patients with functional mitral regurgitation who underwent an isolated MV annuloplasty during a 7-year period (2010-2016) from our institutional database. Preoperative tenting parameters (i.e. tenting height, coaptation length, tenting area, posterior mitral leaflet and anterior mitral leaflet angles and interpapillary muscle distance) were systematically measured. The primary end point was the composite of survival and freedom from adverse cardiac events. The follow-up protocol consisted of a structured clinical questionnaire and an analysis of the echocardiographic data.

RESULTS

A total of 240 patients (mean age 67.8 ± 9.8 years, 57% of men) were analysed. The overall 5-year survival rate for the whole study cohort was 74.7 ± 4.2%, and freedom from adverse cardiac events was 84.8 ± 3.4%. A tenting area ≥2.4 cm2 was identified as a cut-off value, independently predicting the composite primary study end point (hazard ratio 2.0; P = 0.03). Furthermore, a Kaplan-Meier analysis revealed a strong tendency towards worse 5-year outcomes in patients with a tenting area ≥2.4 cm2 (n = 153) versus patients with a tenting area <2.4 cm2 (n = 87) (65.3 ± 5.5% vs 77.1 ± 6.3%; P = 0.06).

CONCLUSIONS

MV annuloplasty is associated with acceptable clinical and echocardiographic outcomes in patients with functional mitral regurgitation 5 years postoperatively. A preoperative tenting area ≥2.4 cm2 showed a strong trend towards a worse 5-year survival rate and an increased risk of adverse cardiac events after an isolated MV annuloplasty.

Mitral regurgitation: lessons learned from COAPT and MITRA-Fr

Recent studies about percutaneous treatment of secondary mitral regurgitation (MR) underlined the importance of left ventricular geometry and features of mitral valve as determinants of procedural and long-term success. Guideline-directed medical therapy (GDMT), transcatheter mitral valve treatment (TMVT) and surgical procedures (mitral valve replacement, mitral valve repair at level of the annulus or subvalvular apparatus) have been extensively evaluated but not adequately compared in current clinical studies. A detailed analysis of the results of the study about transcatheter mitral valve repair would allow to evaluate the safety and effectiveness of such procedure and would provide potential indications for improving the quality of percutaneous and surgical repair in patients with moderate-to-severe secondary MR. Patients with proportionate MR (i.e., MR severity is proportional to the amount of left ventricular dilatation) are prone to respond to the optimization of medical therapy, while patients with disproportionate MR (i.e., MR severity is disproportionately higher than predicted by left ventricular dilatation, with high EROA and small left ventricle) are likely to benefit from additional repair. The identification of specific subpopulation of "high responders", based on the anatomic characteristics of the mitral valve and the relative dimensions of the annulus, the regurgitation and the left ventricle, can also apply to medical therapy. However, some pivotal component of MR (such as the symmetry of tethering and the differences in biomechanical features of leaflets) are not adequately investigated in current studies and warrant further evaluation.

Dynamic Augmentation of Left Ventricle and Mitral Valve Function With an Implantable Soft Robotic Device

Left ventricular failure is strongly associated with secondary mitral valve regurgitation. Implantable soft robotic devices are an emerging technology that enables augmentation of a native function of a target tissue. We demonstrate the ability of a novel soft robotic ventricular assist device to dynamically augment left ventricular contraction, provide native pulsatile flow, simultaneously reshape the mitral valve apparatus, and eliminate the associated regurgitation in an Short-term large animal model of acute left ventricular systolic dysfunction.

Treatment of Functional Mitral Regurgitation in Heart Failure

PURPOSE OF REVIEW

To analyze the current state of the art of functional mitral regurgitation (FMR) treatment.

RECENT FINDINGS

The first-line treatment of severe FMR consists of guideline medical therapy (GMT) and resynchronization therapy when indicated; the impact of new medical therapies like sacubitril/valsartan needs further assessment. Valvular intervention may be considered in FMR symptomatic patients despite GMT, and can be performed surgically or percutaneously. MitraClip is a safe percutaneous procedure associated with symptoms improvement. Recently, the COAPT trial showed superior outcomes for MitraClip versus GMT contrasting the MITRA-FR trial which showed no benefit of MitraClip compared with GMT. These results should be interpreted as complementary rather than opposite. The COAPT trial provided a "proof of concept" that percutaneous treatment of severe FMR in patients without too advanced left ventricular disease translates into a prognostic benefit. Careful patient selection will play a critical role in defining the clinical niche for successful interventions.

Functional Mitral Regurgitation in Heart Failure

Functional mitral regurgitation (FMR) in the setting of left ventricular (LV) dysfunction and heart failure portends a poor prognosis. Guideline-directed medical therapy remains the cornerstone of initial treatment, with emphasis placed on treatment of the underlying LV dysfunction, as FMR is a secondary phenomenon and a disease due to LV remodeling. Surgical correction of FMR is controversial because it typically does not address the underlying mechanism and etiology of the condition. However, new, minimally invasive transcatheter therapies, in particular the MitraClip system, have shown promise in the treatment of FMR in selected patients. This review will summarize the pathophysiology underlying FMR, the prognosis of patients with heart failure and FMR, and the various medical and procedural treatment options currently available and under investigation.

Risk of Ischemic Mitral Regurgitation Recurrence After Combined Valvular and Subvalvular Repair

BACKGROUND

Mitral valve repair (MVr) combined with papillary muscle approximation (PMA) may improve repair durability in severe ischemic mitral regurgitation (MR), when compared with MVr alone. We sought to identify preoperative transthoracic echocardiographic markers associated with MR recurrence after MVr with PMA.

METHODS

A post-hoc analysis was performed on patients with severe ischemic MR who underwent coronary artery bypass graft surgery with MVr with PMA in the papillary muscle approximation randomized trial. The PMA was performed utilizing a 4-mm polytetrafluoroethylene graft placed around the papillary muscles. Linear regression analyses and receiver-operating characteristic curves were used to identify echocardiographic variables and diagnostic models associated with recurrent MR.

RESULTS

There were 48 patients with a mean age of 63 ± 7 years, a left ventricular ejection fraction of 35% ± 5%, and a left ventricular end-diastolic diameter of 63 ± 3 mm. Of these, 37 patients had baseline and 5-year follow-up echocardiograms, with moderate-to-severe MR recurring in 27%. Linear regression analyses revealed associations between preoperative pulmonary artery systolic pressure (standardized beta coefficient, β = 0.49/mm Hg, p = 0.002), MV tenting area (β = 0.47/cm2, p = 0.004), a symmetric MV tethering pattern (β = 0.44, p = 0.007), and left ventricular end-diastolic diameter (β = 0.37/mm, p = 0.02) with follow-up MR grade. The presence of both MV tenting area 3.1 cm2 or greater (area under the curve 0.822) and left ventricular end-diastolic diameter of 64 mm or greater (area under the curve 0.801) was the most robust discriminative model for moderate-to-severe MR recurrence (specificity 92%, sensitivity 69%, area under the curve 0.804, p = 0.003).

CONCLUSIONS

In patients undergoing coronary artery bypass graft surgery with MVr plus PMA, the extent of baseline MV apparatus and left ventricle geometric remodeling identifies patients at increased risk for MR recurrence.