Pathophysiology of Degenerative Mitral Regurgitation

A study protocol to characterise pathophysiological and molecular markers of rheumatic heart disease and degenerative aortic stenosis using multiparametric cardiovascular imaging and multiomics techniques

INTRODUCTION

Rheumatic heart disease (RHD), degenerative aortic stenosis (AS), and congenital valve diseases are prevalent in sub-Saharan Africa. Many knowledge gaps remain in understanding disease mechanisms, stratifying phenotypes, and prognostication. Therefore, we aimed to characterise patients through clinical profiling, imaging, histology, and molecular biomarkers to improve our understanding of the pathophysiology, diagnosis, and prognosis of RHD and AS.

METHODS

In this cross-sectional, case-controlled study, we plan to recruit RHD and AS patients and compare them to matched controls. Living participants will undergo clinical assessment, echocardiography, CMR and blood sampling for circulatory biomarker analyses. Tissue samples will be obtained from patients undergoing valve replacement, while healthy tissues will be obtained from cadavers. Immunohistology, proteomics, metabolomics, and transcriptome analyses will be used to analyse circulatory- and tissue-specific biomarkers. Univariate and multivariate statistical analyses will be used for hypothesis testing and identification of important biomarkers. In summary, this study aims to delineate the pathophysiology of RHD and degenerative AS using multiparametric CMR imaging. In addition to discover novel biomarkers and explore the pathomechanisms associated with RHD and AS through high-throughput profiling of the tissue and blood proteome and metabolome and provide a proof of concept of the suitability of using cadaveric tissues as controls for cardiovascular disease studies.

Moving from left ventricular ejection fraction to deformation imaging in mitral valve regurgitation

The increasing prevalence of valvular heart diseases, specifically mitral regurgitation (MR), underscores the need for a careful and timely approach to intervention. Severe MR, whether primary or secondary, when left untreated leads to adverse outcomes, emphasizing the critical role of a timely surgical or transcatheter intervention. While left ventricular ejection fraction (LVEF) remains the guideline-recommended measure for assessing left ventricle damage, emerging evidence raises concerns regarding its reliability in MR due to its volume-dependent nature. This review summarizes the existing literature on the role of LVEF and deformation imaging techniques, emphasizing the latter's potential in providing a more accurate evaluation of intrinsic myocardial function. Moreover, it advocates the need for an integrated approach that combines traditional with emerging measures, aiming to optimize the management of patients with MR. It attempts to highlight the need for future research to validate the clinical application of deformation imaging techniques through large-scale studies.

Echocardiographic Evaluation of Diastolic Function in Special Populations

Left ventricular (LV) diastolic dysfunction results from a combination of impaired relaxation, reduced restoring forces, and increased chamber stiffness. Noninvasive assessment of diastology uses a multiparametric approach involving surrogate markers of increased filling pressures, which include mitral inflow, septal and lateral annular velocities, tricuspid regurgitation velocity, and left atrial volume index. However, these parameters must be used cautiously. This is because the traditional algorithms for evaluating diastolic function and estimation of LV filling pressures (LVFPs), as recommended by the American Society of Echocardiography and European Association of Cardiovascular Imaging 2016 guidelines, do not apply to unique patients with underlying cardiomyopathies, significant valvular disease, conduction abnormalities, arrhythmias, LV assist devices, and heart transplants, which alter the relation between the conventional indexes of diastolic function and LVFP. The purpose of this review is to provide solutions for evaluating LVFP through illustrative examples of these special populations, incorporating supplemental Doppler indexes, such as isovolumic relaxation time, mitral deceleration time, and pulmonary venous flow analysis, as needed to formulate a more comprehensive approach.

Prognostic Significance of Flail Mitral Leaflet in Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

Despite the growing experience with MitraClip in the broad spectrum of mitral regurgitation (MR), limited data are available regarding the independent prognostic role on survival of different mitral regurgitation etiology subtypes. We sought to evaluate the impact of flail leaflet etiology in a large series of patients with primary MR (PMR) who underwent MitraClip treatment. The study included 588 patients with significant PMR from the multicenter GIOTTO (Italian Society of Interventional Cardiology [GIse] registry Of Transcatheter treatment of mitral valve regurgitaTiOn), stratified into 2 groups according to MR etiology: flail+ (n = 300) and flail- (n = 288). The primary end point was a composite of cardiac death and first rehospitalization for heart failure (HF). To account for the baseline differences, patients were propensity score-matched 1:1. Flail leaflet etiology was present in about a half of the patients. Acute technical success was achieved in 98% of the overall cohort, with no significant differences between the study groups (p = 0.789). At the 2-year Kaplan-Meier analysis, the primary end point occurred in 13% of flail+ patients compared with 23% in flail- (p = 0.009). The flail+ group presented lower rates of both cardiac death and rehospitalization for HF, whereas a similar overall death rate was observed between the groups. A multivariate Cox regression analysis identified flail leaflet etiology as an independent predictor of favorable outcome in terms of the primary end point (hazard ratio 0.141, 95% confidence interval 0.049 to 0.401, p <0.001). After propensity score matching, flail+ patients had confirmed lower rates of cardiac mortality and rehospitalization for HF but similar rates of overall death. In conclusion, flail leaflet-related etiology was common in patients with PMR who underwent MitraClip treatment and was an independent predictor of midterm favorable clinical outcomes.

Escalation from impella 5.5 to ECPELLA support as a bridge to mitral valve surgery in a patient with degenerative mitral regurgitation

Severe mitral regurgitation (MR) is an important cause of acute heart failure and significant contributor to morbidity and mortality. Mechanical circulatory support (MCS) devices such as Impella are readily used to hemodynamically stabilize patients with cardiogenic shock (CS) secondary to this valvular pathology. Impella can also be combined with VA-ECMO to an "ECPELLA" configuration if further escalation of hemodynamic support is needed. We report a case of a 57-year-old female who presented with CS secondary to a perforated anterior mitral valve leaflet and non-ischemic cardiomyopathy that did not stabilize with initial choice of Impella 5.5. She required further escalation from axillary Impella 5.5 to the combined ECPELLA configuration, which allowed hemodynamic stabilization and ultimately a successful high-risk isolated mitral valve replacement. Despite adequate Impella flow, escalation to a combined MCS configuration, such as ECPELLA, may need to be considered upfront for acute valvular insufficiency in the setting of pre-existing cardiomyopathy.

Urgent transcatheter edge-to-edge repair for severe mitral regurgitation with flail leaflet in critically Ill patients

Introduction

Degenerative mitral valve disease (DMR) is a common valvular disorder, with flail leaflets due to ruptured chordae representing an extreme variation of this pathology. Ruptured chordae can present as acute heart failure which requires urgent intervention. While mitral valve surgery is the preferred mode of intervention, many patients have significantly elevated surgical risk and are sometimes considered inoperable. We aim to characterize patients with ruptured chordae undergoing urgent transcatheter edge-to-edge repair (TEER), and to analyze their clinical and echocardiographic outcomes.

Methods

We screened all patients who underwent TEER at a tertiary referral center in Israel. We included patients with DMR with flail leaflet due to ruptured chordae and categorized them into elective and critically ill groups. We evaluated the echocardiographic, hemodynamic, and clinical outcomes of these patients.

Results

The cohort included 49 patients with DMR due to ruptured chordae and flail leaflet, who underwent TEER. Seventeen patients (35%) underwent urgent intervention and 32 patients (65%) underwent an elective procedure. In the urgent group, the average age of the patient was 80.3, with 41.8% being female. Fourteen patients (82%) received noninvasive ventilation, and three patients (18%) required invasive mechanical ventilation. One patient died due to tamponade, while echo evaluation of the other 16 patients demonstrated successful reduction of ≥2 in the MR grade. Left atrial V wave decreased from 41.6 mmHg to 17.9 mmHg (p < 0.001), and the pulmonic vein flow pattern changed from reversal (68.8%) to a systolic dominant flow in all patients (p = 0.001). After the procedure, 78.5% of patients improved to New York Heart Association (NYHA) class I or II (p < 0.001). There was no significant difference in the overall mortality between the urgent and elective groups, with similar 6 months survival rates for each group.

Conclusion

Urgent TEER in patients with ruptured chordae and flail leaflets can be safe and feasible with favorable hemodynamic, echocardiographic, and clinical outcomes.

Mitral and Tricuspid Valve Disease in Athletes

Observing mitral or tricuspid valve disease in an athlete raises many considerations for the clinician. Initially, the etiology must be clarified, with causes differing depending on whether the athlete is young or a master. Notably, vigorous training in competitive athletes leads to a constellation of structural and functional adaptations involving cardiac chambers and atrioventricular valve systems. In addition, a proper evaluation of the athlete with valve disease is necessary to evaluate the eligibility for competitive sports and identify those requiring more follow-up. Indeed, some valve pathologies are associated with an increased risk of severe arrhythmias and potentially sudden cardiac death. Traditional and advanced imaging modalities help clarify clinical doubts, allowing essential information about the athlete's physiology and differentiating between primary valve diseases from those secondary to training-related cardiac adaptations. Remarkably, another application of multimodality imaging is evaluating athletes with valve diseases during exercise to reproduce the sport setting and better characterize the etiology and valve defect mechanism. This review aims to analyze the possible causes of atrioventricular valve diseases in athletes, focusing primarily on imaging applications in diagnosis and risk stratification.

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed “moderate” MR.

3D echocardiography in mitral valve prolapse

Mitral valve prolapse (MVP) is the leading cause of mitral valve surgery. Echocardiography is the principal imaging modality used to diagnose MVP, assess the mitral valve morphology and mitral annulus dynamics, and quantify mitral regurgitation. Three-dimensional (3D) echocardiographic (3DE) imaging represents a consistent innovation in cardiovascular ultrasound in the last decades, and it has been implemented in routine clinical practice for the evaluation of mitral valve diseases. The focus of this review is the role and the advantages of 3DE in the comprehensive evaluation of MVP, intraoperative and intraprocedural monitoring.

3D mitral annulus echocardiography assessment in patients affected by degenerative mitral regurgitation who underwent mitral valve repair with flexible band

BACKGROUND

Degenerative mitral valve (MV) regurgitation (DMR) shows significative mitral annulus (MA) alterations; mitral valve repair (MVR) seeks to restore annular geometry and function, and the current use of flexible band seams to respect most annular mobility reducing parietal stress. Parameters of MV geometry obtained by 3D transesophageal echocardiography (3D-TTE) analysis are crucial for surgical planning and postoperative success. The aim of this study was to assess, by means of a dedicated software, the variations of MA geometry and function in patients affected by DMR compared to controls and after MVR with flexible band.

METHODS

We enrolled 32 patients (cases) with severe DMR who underwent MVR using flexible band; we compare this group with 20 controls. The TEE with 3D MV images acquisition was performed in both groups and then analyzed in postprocessing by using a dedicated software.

RESULTS

There were no anthropometrics differences between cases and controls, both presented normal left ventricular ejection fraction. DMR group showed a significant increase of annulus dimensional parameters (p = .001) and alteration of nonplanarity comparing to controls (p < .05). The annuloplasty with flexible band induces a considerable reduction of MV dimensions comparing to preoperative data and restores physiological mobility and nonplanarity. There were no statistical differences between postoperative DMR and controls data, except for nonplanarity parameters (p ~.05), maybe influenced by hemodynamic settings.

CONCLUSIONS

MVR with annuloplasty using flexible band appears able to reinstate a more physiological anatomic conformation of the MA, without compromising its dynamic properties.

Mineralocorticoid Receptor Antagonists Mitigate Mitral Regurgitation-Induced Myocardial Dysfunction

Mitral regurgitation (MR), the disruption of the mitral valve, contributes to heart failure (HF). Under conditions of volume overload, excess mineralocorticoids promote cardiac fibrosis. The mineralocorticoid receptor antagonist spironolactone is a potassium-sparing diuretic and a guideline-recommended therapy for HF, but whether it can ameliorate degenerative MR remains unknown. Herein, we investigate the efficacy of spironolactone in improving cardiac remodeling in MR-induced HF compared with that of a loop diuretic, furosemide. Using a novel and mini-invasive technique, we established a rat model of MR. We treated the rats with spironolactone or furosemide for twelve weeks. The levels of cardiac fibrosis, apoptosis, and stress-associated proteins were then measured. In parallel, we compared the cardiac remodeling of 165 patients with degenerative MR receiving either spironolactone or furosemide. Echocardiography was performed at baseline and at six months. In MR rats treated with spironolactone, left ventricular function—especially when strained—and the pressure volume relationship significantly improved compared to those of rats treated with furosemide. Spironolactone treatment demonstrated significant attenuation of cardiac fibrosis and apoptosis in left ventricular tissue compared to furosemide. Further, spironolactone suppressed the expression of apoptosis-, NADPH oxidase 4 (NOX4)- and inducible nitric oxide synthase (iNOS)-associated proteins. Similarly, compared with MR patients receiving furosemide those prescribed spironolactone demonstrated a trend toward reduction in MR severity and showed improvement in left ventricular function. Collectively, MR-induced cardiovascular dysfunction, including fibrosis and apoptosis, was effectively attenuated by spironolactone treatment. Our findings suggest a potential therapeutic option for degenerative MR-induced HF.

Mitral Annular Elasticity Determines Severity of Regurgitation in Barlow's Disease

AIMS

Barlow's disease (BD) with late systolic mitral regurgitation provides diagnostic and therapeutic challenges. The mechanisms of the regurgitation are still unclear. We hypothesized that the onset and the severity of late systolic regurgitation are determined by annulus dynamics and the mechanical stresses imposed by the left ventricle.

METHODS AND RESULTS

Ten patients with BD and mitral annulus disjunction (MAD) were compared with ten healthy controls. Resting blood pressure (BP) was measured and transthoracic three-dimensional (3D) echocardiography was analyzed using a holographic display that allows tracking and measurements of mitral annulus surface area (ASA) throughout the cardiac cycle. A novel annulus elastance index (dASA/dP) was calculated between aortic valve opening and onset of mitral regurgitation. Severity of MAD was quantified as the disjunction index (mm*degree). Leaflet coaptation area was calculated using a finite element model. Peak systolic ASA in controls and patients were 9.3±0.6 and 21.1±3.1 cm², respectively (p<0.001). In patients ASA increased rapidly during LV ejection and onset of mitral regurgitation coincided closely with peak upslope of annulus area change (dASA/dt). The finite element model showed a close association between rapid annulus displacement and coaptation area deficit in BD. Systolic annulus elastance index (0.058±0.036 cm²/mmHg) correlated strongly with disjunction index (r=0.91, p<0.0001). Moreover, regurgitation volume showed a positive correlation with systolic BP (r=0.80, p<0.01) CONCLUSION: The present pilot study supports the hypothesis that annulus dilatation may accentuate mitral valve regurgitation in patients with Barlow's disease. A novel annulus elastance index may predict the severity of mitral valve regurgitation in selected patients.

Outcome of consistent guideline-based tricuspid management in patients undergoing degenerative mitral regurgitation correction

Objectives

Despite coherent guidelines, management of functional tricuspid regurgitation (FTR) consequences on outcome in the context of degenerative mitral regurgitation (DMR) remains controversial due to lacking series of large magnitude with rigorous application of tricuspid guidelines and strict long-term echocardiographic follow-up. Thus, we aimed at gathering such a cohort to examine outcomes of patients undergoing DMR surgery following tricuspid surgery guidelines.

Methods

All consecutive patients with isolated DMR 2005-2015 operated on with baseline FTR assessment and tricuspid annulus diameter measurement were identified. Operative complications, postoperative tricuspid regurgitation incidence, and survival were assessed overall and stratified by guideline-based tricuspid annuloplasty (TA) indication (severe FTR or tricuspid annulus diameter ≥40 mm).

Results

Among 441 patients with DMR undergoing mitral repair (66 ± 13 years, 30% female, ejection fraction 66 ± 10%, systolic pulmonary artery pressures 39 ± 12 mm Hg) followed 6 [3-9] years, patients with TA (n = 234, 53%) had generally similar presentation versus without TA (n = 207, 47%; all P ≥ .2) except for more atrial fibrillation and larger left ventricle (both P ≥ .0003). Patients with TA showed longer bypass time, more maze procedures (all P ≤ .001), but hospital stay, renal-failure, pacemaker implantation, and operative mortality (overall 0.9%) were comparable (all P ≥ .2). Postoperative incidence of moderate/severe FTR (0% at 1 year) became over time greater among patients without TA (5-year 8% [4%-13%] vs 3% [1%-11%] and 10-year 10% [6%-16%] vs 4% [1%-16%], P = .01). Survival (95% confidence interval) throughout follow-up was 85% (77%-89%) at 10 years, with hazard ratio 0.57 (0.29-1.10), P = .09. for patients with TA versus without.

Conclusions

In this large surgical DMR cohort, guideline-based FTR management was safe and effective. While long-term mortality did not reach significance, postoperative incidence of moderate/severe FTR, overall low, was nevertheless greater in patients who did not appear to require TA at surgery and linked to tricuspid annular dimension. Thus, future multicenter prospective cohorts with long-term follow-up are warranted to re-examine thresholds for TA performance and impact on survival.

Aggravation of functional mitral regurgitation on left ventricle stiffness in type 2 diabetes mellitus patients evaluated by CMR tissue tracking

BACKGROUND

Functional mitral regurgitation (FMR) is one of the most common heart valve diseases in diabetes and may increase left ventricular (LV) preload and aggravate myocardial stiffness. This study aimed to investigate the aggravation of FMR on the deterioration of LV strain in type 2 diabetes mellitus (T2DM) patients and explore the independent indicators of LV peak strain (PS).

MATERIALS AND METHODS

In total, 157 T2DM patients (59 patients with and 98 without FMR) and 52 age- and sex-matched healthy control volunteers were included and underwent cardiac magnetic resonance examination. T2DM with FMR patients were divided into T2DM patients with mild (n = 21), moderate (n = 19) and severe (n = 19) regurgitation. LV function and global strain parameters were compared among groups. Multivariate analysis was used to identify the independent indicators of LV PS.

RESULTS

The T2DM with FMR had lower LV strain parameters in radial, circumferential and longitudinal direction than both the normal and the T2DM without FMR (all P < 0.05). The mild had mainly decreased peak diastolic strain rate (PDSR) compared to the normal. The moderate had decreased peak systolic strain rate (PSSR) compared to the normal and PDSR compared to the mild and the normal. The severe FMR group had decreased PDSR and PSSR compared to the mild and the normal (all P < 0.05). Multiple linear regression showed that the regurgitation degree was independent associated with radial (β = - 0.272), circumferential (β = - 0.412) and longitudinal (β = - 0.347) PS; the months with diabetes was independently associated with radial (β = - 0.299) and longitudinal (β = - 0.347) PS in T2DM with FMR.

CONCLUSION

FMR may aggravate the deterioration of LV stiffness in T2DM patients, resulting in decline of LV strain and function. The regurgitation degree and months with diabetes were independently correlated with LV global PS in T2DM with FMR.

Asian Pacific Society of Cardiology Consensus Recommendations on the Use of MitraClip for Mitral Regurgitation

Transcatheter mitral valve repair with the MitraClip, a catheter-based percutaneous edge-to-edge repair technique to correct mitral regurgitation (MR), has been demonstrated in Western studies to be an effective and safe MR treatment strategy. However, randomised clinical trial data on its use in Asian-Pacific patients is limited. Hence, the Asian Pacific Society of Cardiology convened an expert panel to review the available literature on MitraClip and to develop consensus recommendations to guide clinicians in the region. The panel developed statements on the use of MitraClip for the management of degenerative MR, functional MR, and other less common indications, such as acute MR, dynamic MR, hypertrophic obstructive cardiomyopathy, and MR after failed surgical repair. Each statement was voted on by each panel member and consensus was reached when 80% of experts voted ‘agree’ or ‘neutral’. This consensus-building process resulted in 10 consensus recommendations to guide general cardiologists in the evaluation and management of patients in whom MitraClip treatment is being contemplated.

Current Status and Future Prospects of Transcatheter Mitral Valve Replacement: JACC State-of-the-Art Review

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, it confers a poorer prognosis. Catheter-based repair therapies face some limitations like their applicability on challenging anatomies and the potential recurrence of significant MR over time. Transcatheter mitral valve replacement (TMVR) has emerged as a less invasive approach potentially overcoming some of the current limitations associated with transcatheter mitral valve repair. Several devices are under clinical investigation, and a growing number of systems allow for a fully percutaneous transfemoral approach. In this review, the authors aimed to delineate the main challenges faced by the TMVR field, to highlight the key aspects for procedural planning, and to describe the clinical results of the TMVR systems under clinical investigation. Finally, they also discuss what the future perspectives are for this emerging field.

Assessment of mitral regurgitation and mitral complex geometry in patients after transcatheter aortic valve implantation

Introduction

Mitral regurgitation (MR) of varying degrees and mechanisms is a common finding in patients with aortic stenosis with different improvement after transcatheter aortic valve implantation (TAVI).

Aim

To evaluate the impact of TAVI on mitral complex geometry and the degree of MR.

Material and methods

A total of 31 patients (29.0% males) with severe aortic stenosis and moderate or severe MR at the baseline who underwent TAVI were included in this study. Clinical and echocardiographic characteristics were determined at baseline and at 6 and 12 months.

Results

After TAVI, decrease of MR vena contracta width (p = 0.00002, p = 0.00004), aorto-mural mitral annulus diameter (p = 0.00008, p = 0.02), increase of mitral annular plane systolic excursion (p = 0.0004, p = 0.0003), left ventricular stroke volume (p = 0.0003, p = 0.0004), ejection fraction (p = 0.0004, p = 0.01) and decrease of major dimension of left ventricle in three chamber view (p = 0.05, p = 0.002) were observed in patients at both time points. Additionally, we observed a decrease of distance between the head of the papillary muscles (p = 0.003) at 6 months and a decrease of left atrium volume index (p = 0.01) and systolic pulmonary artery pressure (p = 0.01) at 12 months.

Conclusions

Patients with moderate or severe MR undergoing TAVI achieved significant improvement of mitral valve complex function resulting in the reduction of MR degree.

Successful MitraClip Implantation in a Barlow's Valve: A Feasible Alternative?

•Barlow's disease is a degenerative mitral valvulopathy with highly complex anatomy. •Barlow's disease is classically unfavorable for TMVr using MitraClip. •Patients with Barlow's disease, SAM, and high surgical risk may be candidates for TMVr.

Combined Mitral and Aortic Valve Surgery: 17 Years' Experience in a Single Center

Background and objective:

It is not uncommon that patients requiring valve surgery have several simultaneous valvular dysfunctions. Combined aortic and mitral valve surgery is the most common form of double-valve surgery. The aim of this study was to analyze and present the outcomes of simultaneous aortic and mitral valve surgery in a single center in a real-life setting.

Methods:

The study population consisted of 150 patients operated in the Kuopio University Hospital from 2004 to 2020. All patients undergoing concomitant mitral and aortic valve surgery were included. Four groups were formed based on either the etiology or pathophysiology of the valvular dysfunction. The most common combination was mitral regurgitation with aortic regurgitation (n = 72, 48%), followed by mitral regurgitation with aortic stenosis (n = 37, 25%), endocarditis (n = 29, 19%), and mitral stenosis with aortic regurgitation or stenosis (n = 12, 8%). Concomitant coronary artery revascularization was performed in 37 (25%) patients and tricuspid valve repair in 26 (17%) patients.

Results:

Operative mortality was 2% and 30-day mortality was 7%. Overall survival was 86%, 78%, and 61% in 3, 5, and 10 years, respectively. Patients with endocarditis were significantly more morbid, and more often than other patients had to undergo an emergency operation. There were no significant differences between the groups in terms of early and late survival. In the overall cohort, the EuroSCORE II value, increased pulmonary artery pressure, decreased glomerular filtration, and length of the operation displayed a negative correlation with survival.

Conclusions:

Despite the challenging nature of multivalvular heart disease, surgery is a safe method of treatment with good short- and long-term outcomes.

Update of Patient Selection and Therapeutic Strategy Using MitraClip

Patients with advanced heart failure often accompany severe function mitral regurgitation refractory to optimal medical therapy. Degenerative mitral regurgitation also develops due to various degeneration of mitral valve. Surgical intervention to the mitral valve might be effective in some cases, but it is challenging for the high-risk cases. Recently, percutaneous edge-to-edge mitral valve repair using the MitraClip system, which enables us to approach the mitral valve at relatively low risk, has developed. Two major prospective randomized control trials have been conducted to investigate the clinical advantage of MitraClip system over optimal medical therapy in patients with severe mitral regurgitation; both showed controversial conclusions. Now is a time to consider optimal patient selection and therapeutic strategy using MitraClip system.

Degenerative mitral regurgitation

PURPOSE OF REVIEW

Degenerative mitral regurgitation (DMR) continues to be an important cause of morbidity and mortality with surgical mitral valve repair remaining the gold standard for the treatment of severe disease. The purpose of this review is to summarize recent advances in the understanding of DMR as well as the progress made in its assessment with a focus on imaging techniques.

RECENT FINDINGS

Recent insights into the anatomy and physiology of DMR challenge the assumption that fibroelastic deficiency and Barlow disease are part of a single DMR spectrum. Advances in echocardiography and cardiovascular MRI have the potential to improve quantification of mitral regurgitation, provide unique information on prognosis and impact of DMR, further the association between DMR and arrhythmic risk and aide in decision-making for DMR treatment.

SUMMARY

With growing interest in the use of noninvasive transcatheter therapies in the mitral valve space, comprehensive assessment of the mitral valve is critical to instruct decision-making and guide therapeutic strategy.

Systolic Blood Pressure and Risk of Valvular Heart Disease: A Mendelian Randomization Study

Importance

Modifiable risk factors for valvular heart disease remain largely unknown, which limits prevention and treatment.

Objective

To assess the association between systolic blood pressure (BP) and major valvular heart disease.

Design, Setting, and Participants

A UK Biobank population-based cohort of 502 602 men and women aged 40 to 96 years at baseline was evaluated through mendelian randomization using individual participant data. Inclusion criteria were valid genetic data and BP measurements. The participants were recruited between 2006 and 2010; data analysis was performed from June 2018 to January 2019.

Exposures

Systolic BP was measured during clinical assessment and instruments for the genetic effect of high BP were identified from variants that were independently (linkage disequilibrium threshold of r2<0.1) associated with systolic BP with minor allele frequency greater than 0.01. A total of 130 single-nucleotide polymorphisms that have been shown to be associated with systolic BP in a genome-wide association meta-analysis involving 1 million participants of European ancestry were selected.

Main Outcomes and Measures

Incident aortic stenosis, aortic regurgitation, and mitral regurgitation, individually and combined. Cases were largely based on hospital records linked to the UK Biobank with International Classification of Diseases and Health Related Problems, Tenth Revision codes.

Results

Of the 502 602 individuals screened, 329 237 participants (177 741 [53.99%] women; mean [SD] age, 56.93 [7.99] years) had valid genetic data and BP measurements; of this cohort, 3570 individuals (1.08%) had a diagnosis of valvular heart disease (aortic stenosis, 1491 [0.45%]; aortic regurgitation, 634 [0.19%]; and mitral regurgitation, 1736 [0.53%]). Each genetically associated 20-mm Hg increment in systolic BP was associated with an increased risk of aortic stenosis (odds ratio [OR], 3.26; 95% CI, 1.50-7.10), aortic regurgitation (OR, 2.59; 95% CI, 0.75-8.92), and mitral regurgitation (OR, 2.19; 95% CI, 1.07-4.47), with no evidence for heterogeneity by type of valvular heart disease (P = .90). Sensitivity analyses confirmed the robustness of the association.

Conclusions and Relevance

Lifetime exposure to elevated systolic BP appears to be associated with an increased risk of major valvular heart disease.

Mitral Regurgitation: Anatomy, Physiology, and Pathophysiology-Lessons Learned From Surgery and Cardiac Imaging

The normal mitral valve is a dynamic structure that permits blood to flow from the left atrial (LA) to left ventricle (LV) during diastole and sealing of the LA from the LV during systole. The main components of the mitral apparatus are the mitral annulus (MA), the mitral leaflets, the chordae tendineae, and the papillary muscles (PM) (Figure 1). Normal valve function is dependent on the integrity and normal interplay of these components. Abnormal function of any one of the components, or their interplay can result in mitral regurgitation (MR). Understanding the anatomy and physiology of all the component of the mitral valve is important for the diagnosis, and for optimal planning of repair procedures. In this review we will focus first on normal anatomy and physiology of the different parts of the mitral valve (MA, leaflets, chordae tendineae, and PM). In the second part we will focus on the pathologic anatomic and physiologic derangements associated with different types of MR.

Functional tricuspid regurgitation of degenerative mitral valve disease: a crucial determinant of survival

Aims 

To assess functional tricuspid regurgitation (FTR) determinants, consequences, and independent impact on outcome in degenerative mitral regurgitation (DMR).

Methods and results 

All patients diagnosed with isolated DMR 2003–2011, with structurally normal tricuspid leaflets, prospective FTR grading and systolic pulmonary artery pressure (sPAP) estimation by Doppler echocardiography at diagnosis were identified and long-term outcome analysed. The 5083 DMR eligible patients [63 ± 16 years, 47% female, ejection fraction (EF) 63 ± 7%, and sPAP 35 ± 13 mmHg] presented with FTR graded trivial in 45%, mild in 37%, moderate in 15%, and severe in 3%. While pulmonary hypertension (PHTN-sPAP ≥ 50 mmHg) was the most powerful FTR severity determinant, other strong FTR determinants were older age, female sex, lower left ventricle EF, DMR, and particularly atrial fibrillation (AFib) (all P ≤ 0.002). Functional tricuspid regurgitation moderate/severe was independently linked to more severe clinical presentation, more oedema, lower stroke volume, and impaired renal function (P ≤ 0.01). Survival (95% confidence interval) throughout follow-up [70% (69–72%) at 10 years] was strongly associated with FTR severity [82% (80–84%) for trivial, 69% (66–71%) for mild, 51% (47–57%) for moderate, and 26% (19–35%) for severe, P &lt; 0.0001]. Excess mortality persisted after comprehensive adjustment [adjusted hazard ratio 1.40 (1.18–1.67) for moderate FTR and 2.10 (1.63–2.70) for severe FTR, P ≤ 0.01]. Excess mortality persisted adjusting for sPAP/right ventricular function (P &lt; 0.0001), by matching [adjusted hazard ratios 2.08 (1.50–2.89), P &lt; 0.0001] and vs. expected survival [risk ratio 1.79 (1.48–2.16), P &lt; 0.0001]. Within 5-year of diagnosis valve surgery was performed in 73% (70–75%) and 15% (13–17%) of severe and moderate DMR and in only 26% (19–34%) and 6% (4–8%) of severe and moderate FTR. Valvular surgery improved outcome without alleviating completely higher mortality associated with FTR (P &lt; 0.0001).

Conclusion 

In this large DMR cohort, FTR was frequent and causally, not only linked to PHTN but also to other factors, particularly AFib. Higher FTR severity is associated at diagnosis with more severe clinical presentation. Long term, FTR is independently of all confounders, associated with considerably worse mortality. Functional tricuspid regurgitation moderate and even severe is profoundly undertreated. Thus careful assessment, consideration for tricuspid surgery, and testing of new transcatheter therapy is warranted.

Mitral annulus morphometry in degenerative mitral regurgitation phenotypes

OBJECTIVES

Degenerative mitral regurgitation (DMR) is classified into different phenotypes based on the extent of leaflet degeneration. Our aim is to demonstrate that phenotype complexity predicts the extent of structural abnormalities of mitral annulus (MA).

METHODS AND RESULTS

Seventy-five patients with DMR and severe valve regurgitation and 23 patients with normal mitral valve were studied using 3D transesophageal echocardiography. Classification of DMR was done by allocating each 3D echocardiography result under five categories: fibroelastic deficiency (FED), FED+, forme fruste, Barlow's disease Mitral annular disjunction (BD MAD)- or BD MAD+. MA was reconstructed in early systole and in end systole. We tested for a trend toward enlargement and flattening of MA in end systole and for a difference in MA dynamics from early systole to end systole with a worsening of DMR phenotype, in the whole spectrum of subjects ranging from controls to BD MAD+. A significant trend was observed toward larger anteroposterior diameter, intercommissural diameter, annulus circumference, and annulus area (P < .001). A reduction was found in annulus height to commissural width ratio (P = .003): This indicates a progressive MA flattening. Prolapse height and prolapse volume tended to be larger (P < .001).

CONCLUSION

Based on the extent of leaflet degeneration, DMR is classified into different phenotypes. As the disease progresses, a related increase in MA size is found, with rounder annular shape, loss of saddle shape, and increase in height and volume of leaflet prolapse. The most pronounced alterations are found in BD MAD+.

Recent advances in understanding and managing mitral valve disease

Interest in the mitral valve has increased over the past few years with the development of new technologies that allow intervention in patients previously deemed too ill for treatment. This increased attention has resulted in a significant increase in publications on the mitral valve, the majority of which focus on mitral regurgitation and mitral valve surgery/intervention. The focus of this review is on publications in the past few years that offer additional insights into our understanding and management of mitral valve disease and specifically mitral regurgitation. It will discuss mitral valve anatomy, epidemiology of mitral valve disease, changes in the 2017 management guidelines, management of mitral bioprosthetic valves, transcatheter mitral valve procedures and the repair of rheumatic valves.

Echocardiographic prediction of surgical reparability in degenerative mitral regurgitation due to leaflet prolapse: a review

Introduction: Despite current guidelines provide recommendations for the optimal management of degenerative mitral regurgitation (MR), this condition remains often undertreated with delay in surgical referral and dismal effect on outcomes. Areas covered: This review focuses on the role of echocardiography in guiding mitral valve (MV) surgical repair in degenerative MR due to leaflet prolapse. Expert opinion: A stepwise protocol-driven echocardiography shared by referring physician and surgeon may help to guide referral to surgical repair in degenerative MR. This protocol particularly is useful to identify the ideal patho-anatomy for a successful and durable repair especially when early surgery is proposed and to refer the patient to centers of excellence in case of complex anatomy. Nearly 100% repair rate can be achieved when the surgical technique is adapted to the lesions seen in each valve. Three-dimensional echocardiography predicts repair complexity may be useful and should therefore be implemented. However, the current literature is far from comprehensive deriving from small, single-center studies. Therefore, reproducibility and external validation, especially with newly developed quantitative automated software, are still needed.

Sympathetic nervous system and cardiovascular risk in mitral valve prolapse

Mitral valve prolapse (MVP) represents a frequent cardiovascular condition associated with increased cardiovascular risk, which may have progressive course and become malignant. Dysregulation of autonomic nervous system - especially sympathetic overdrive – is one of the factors considered to play a key role in its aetiology and development. There is a growing evidence of a large impact of sympathetic system on the development of MVP. Exaggerated sympathetic activity may lead to morphologic changes in valves tissue such as thickening and redundancy. Nowadays, few investigative methods are known for evaluation of the regulatory state of sympathetic nervous system, which could be, theoretically, used to identify the subjects with sympathetic overactivity associated with an increased cardiovascular risk. Electrodermal activity or blood pressure variability represent promising non-invasive methods for evaluation of the regulatory outputs of sympathetic nervous system. There is a possibility to extend a set of investigative methods in MVP and include the monitoring of sympathetic activity in the assessment of cardiovascular risk. This article summarizes knowledge about pathogenesis, diagnostic and therapeutical approaches of MVP, and brings some novel insights on the parameters of autonomic nervous regulation, which haven’t yet been used in cardiovascular risk assessment in MVP.

The Cardioband transcatheter annular reduction system

Surgical implantation of a complete or incomplete ring to reduce the mitral valve annulus and improve leaflet coaptation is the foundation of valve repair for degenerative and functional mitral and tricuspid regurgitation. The Cardioband system (Edwards Lifesciences, Irvine, CA, USA) is a catheter-delivered annular reduction system that mimics the surgical approach. Sequential anchors are used to secure the Cardioband implant from trigone to trigone. The Cardioband implant is contracted under transesophageal guidance until valvular regurgitation is reduced. In the initial clinical experience, the Cardioband system was safely deployed in patients with clinically significant functional mitral regurgitation (MR) and yielded durable MR reduction, improved quality of life, and improved exercise capacity. The early and still-evolving Cardioband experience for tricuspid regurgitation is also promising. The ongoing pivotal ACTIVE Trial is designed to demonstrate the superiority of the Cardioband system to guideline-directed medical therapy in patients with clinically significant functional MR (FMR) using a composite endpoint of mortality, heart failure (HF) hospitalization, quality of life, and exercise capacity.

Advanced Imaging Techniques for Mitral Regurgitation

Mitral regurgitation (MR) is one of the most commonly encountered valvular lesions in clinical practice. MR can be either primary (degenerative) or secondary (functional) depending on the etiology of MR and the pathology of the mitral valve (MV). Echocardiography is the primary diagnostic tool for MR and is key in determining this etiology as well as MR severity. While clinicians usually turn to 2 Dimensional echocardiography as first-line imaging, 3 Dimensional echocardiography (3DE) has continually shown to be superior in terms of describing MV anatomy and pathology. This review article elaborates on 3DE techniques, modalities, and advances in software. Furthermore, the article demonstrates how 3DE has reformed MR evaluation and has played a vital role in determining patient management.

Sudden Cardiac Death Risk Prediction: The Role of Cardiac Magnetic Resonance Imaging

Sudden cardiac death (SCD) accounts for more than 4 million global deaths per year. While it is most commonly caused by coronary artery disease, a final common pathway of ventricular arrhythmias is shared by different etiologies. The most effective primary and secondary prevention strategy is an implantable cardioverter-defibrillator (ICD). The decision to implant an ICD for primary prevention is largely based on a left ventricular ejection fraction ≤ 35%, but this criterion in isolation is neither sensitive nor specific. Novel imaging parameters hold promise to improve ICD candidate selection. Cardiac magnetic resonance (CMR) imaging is a powerful and versatile technique, with the ability to comprehensively assess cardiac structure and function. A range of variables based on CMR techniques (late gadolinium enhancement, T₁ mapping, T₂* relaxometry, deformation imaging) have been associated with ventricular arrhythmias and SCD risk. The role of CMR in the estimation of ventricular arrhythmias and SCD risk in coronary artery disease, nonischemic cardiomyopathies, cardiac transplant, iron-overload cardiomyopathy and valvular heart disease is reviewed in this article. Prospective, randomized trials and standardization of CMR techniques are required before its routine use can be recommended for guiding SCD prevention strategies.