Description and prevalence of ventricular mitral annular disjunction: variation of normality or pathological variant?

INTRODUCTION AND OBJECTIVES

The aim of this study was to investigate a new variation of the atrial wall-mitral annulus-ventricular wall junction along the mural mitral leaflet and commissures: the ventricular mitral annular disjunction (v-MAD). This new variant is characterized by spatial displacement of the mitral leaflet hinge line by more than 2 mm toward the left ventricle.

METHODS

We examined a cohort of autopsied human hearts (n = 224, 21.9% females, 47.9 ± 17.6 years) from patients without known cardiovascular disease to identify the presence of v-MAD.

RESULTS

More than half (57.1%) of the hearts showed no signs of MAD in the mural mitral leaflet or mitral commissures. However, v-MAD was found in 23.6% of cases, located within 20.1% of mural leaflets, 2.2% in superolateral commissures, and 1.3% in inferoseptal commissures. V-MAD was not uniformly distributed along the mitral annulus circumference, with the most frequent site being the P2 scallop (19.6% of hearts). The v-MAD height was significantly greater in mural leaflets than in commissures (4.4 mm ± 1.2 mm vs 2.1 mm ± 0.1 mm; P < .001). No specific variations in mitral valve morphology or anthropometrical features of donors were associated with the presence or distribution of v-MADs. Microscopic examinations revealed the overlap of the thin layer of atrial myocardium over ventricular myocardium in areas of v-MAD.

CONCLUSIONS

Our study is the first to present a detailed definition and morphometric description of v-MAD. Further studies should focus on the clinical significance of v-MAD to elucidate whether it represents a benign anatomical variant or a significant clinical anomaly.

Insights into the Inherited Basis of Valvular Heart Disease

PURPOSE OF REVIEW: Increases in the availability of genetic data and advances in the tools and methods for their analyses have enabled well-powered genetic association studies that have significantly enhanced our understanding of the genetic factors underlying both rare and common valve diseases. Valvular heart diseases, such as congenital valve malformations and degenerative valve lesions, increase the risk of heart failure, arrhythmias, and sudden death. In this review, we provide an updated overview of our current understanding of the genetic mechanisms underlying valvular heart diseases. With a focus on discoveries from the past 5 years, we describe recent insights into genetic risk and underlying biological pathways. RECENT FINDINGS: Recently acquired knowledge around valvular heart disease genetics has provided important insights into novel mechanisms related to disease pathogenesis. Newly identified risk loci associated valvular heart disease mainly regulate the composition of the extracellular matrix, accelerate the endothelial-to-mesenchymal transition, contribute to cilia formation processes, and play roles in lipid metabolism. Large-scale genomic analyses have identified numerous risk loci, genes, and biological pathways associated with degenerative valve disease and congenital valve malformations. Shared risk genes suggest common mechanistic pathways for various valve pathologies. More recent studies have combined cardiac magnetic resonance imaging and machine learning to offer a novel approach for exploring genotype-phenotype relationships regarding valve disease. Progress in the field holds promise for targeted prevention, particularly through the application of polygenic risk scores, and innovative therapies based on the biological mechanisms for predominant forms of valvular heart diseases.

Characteristics and outcomes of patients undergoing transcatheter mitral valve replacement with the Tendyne system

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has emerged as alternative to transcatheter edge-to-edge repair (TEER) for treatment of mitral regurgitation (MR); however, the role of TMVR with the Tendyne system among established treatments of MR is not well defined. We assessed characteristics and outcomes of patients treated with the Tendyne system in the current clinical practice.

METHODS

We reviewed patients who underwent cardiac computed tomography and were judged eligible for the Tendyne system.

RESULTS

A total of 63 patients were eligible for TMVR with the Tendyne system. Of these, 17 patients underwent TMVR, and 46 were treated by TEER. Patients treated with the Tendyne system were more likely to have a high transmitral pressure gradient and unsuitable mitral valve morphology for TEER than those treated with TEER. TMVR with the Tendyne system reduced the severity of MR to less than 1 + in 94.1% of the patients at discharge and achieved a greater reduction in left ventricular (LV) end-diastolic volume at the 30-day follow-up compared with TEER. In contrast, patients treated with the Tendyne system had a higher 30-day mortality than those treated with TEER, while the mortality between 30 days and one year was comparable between Tendyne and TEER.

CONCLUSIONS

Among patients eligible for the Tendyne system, approximately a quarter of the patients underwent TMVR with the Tendyne system, which led substantial reduction of MR and LV reverse remodeling than TEER. In contrast, the 30-day mortality rate was higher after TMVR with the Tendyne compared to TEER.

Impact of a combination of pimobendan, furosemide, and enalapril on heart rate variability in naturally occurring, symptomatic, myxomatous mitral valve degeneration dogs

BACKGROUND

Pimobendan, diuretics, and an angiotensin-converting enzyme inhibitor (ACEi) are widely used for the management of chronic valvular heart disease in dogs; however, the effects of that combination on heart rate variability (HRV) are unknown. The purpose of this study was to assess the HRV of symptomatic myxomatous mitral valve degeneration (MMVD) dogs in response to therapy with a combination of pimobendan, diuretics, and ACEi.

RESULTS

MMVD stage C (n = 17) dogs were enrolled and a 1-hour Holter recording together with echocardiography, blood pressure measurement, and blood chemistry profiles were obtained before and 1, 3, and 6 months after oral treatment with pimobendan (0.25 mg/kg), enalapril (0.5 mg/kg), and furosemide (2 mg/kg) twice daily. The results revealed that MMVD stage C dogs at the baseline had lower values of time-domain indices, low frequency (LF), high frequency (HF), and total power, as well as higher value of LF/HF. Triple therapy significantly increases these parameters in MMVD stage C dogs (P < 0.05). A positive moderate correlation was observed between time domain parameters and a left ventricular internal diastole diameter normalized to body weight (P < 0.05).

CONCLUSIONS

It can be concluded that MMVD stage C dogs possess low HRV due to either the withdrawal of parasympathetic tone or enhanced sympathetic activation, and a combination therapy was shown to enhance cardiac autonomic modulation inferred from the increased heart rate variability. Therefore, a combination therapy may be useful for restoring normal autonomic nervous system activity in dogs with MMVD stage C.

Contemporary treatment of mitral valve disease with transcatheter mitral valve implantation

BACKGROUND

Transcatheter mitral valve implantation (TMVI) with self-expanding (SAV) or balloon-expandable (BAV) valves are rising as promising treatment options for high-risk patients with symptomatic mitral valve (MVD) disease unsuitable for alternative treatment options.

AIMS

The aim of this study was to examine the clinical, procedural and outcome parameters of patients undergoing SAV or BAV for MVD.

METHODS

In this observational and single-center case series, fifteen consecutive patients treated with the Tendyne Mitral Valve System (SAV) and thirty-one patients treated with SAPIEN prosthesis (BAV) were included.

RESULTS

The patients (aged 78 years [interquartile range (IQR): 65.5 to 83.1 years], 41% women, EuroSCORE II 10.3% [IQR: 5.5 to 17.0%] were similar regarding baseline characteristics, despite a higher rate of prior heart valve surgery and prevalence of MV stenosis in the SAV-group. At discharge, the SAV-group had a mean transvalvular gradient of 4.2 mmHg, whereas the BAV-group had a mean transvalvular gradient of 6.2 mmHg. None or trace paravalvular leakage (PVL) was assessed in 85% in SAV-group and 80% in the BAV-group. 320 day all-cause and cardiac mortality rates were comparable in both groups (SAV: 26.7% vs BAV: 20%, p = 0.60). Four deaths occurred early in the SAV-group until 32 days of follow-up.

CONCLUSIONS

In high-risk patients with MVD, TMVI presents a promising treatment option with encouraging mid-term outcomes and good valve durability. TMVI either with BAV or SAV may be developed to an established treatment option.

High lipoprotein(a) levels and mitral valve disease: A systematic review

AIMS

The role of lipoprotein(a) [Lp(a)] as a possibly causal risk factor for atherosclerotic artery disease and aortic valve stenosis has been well established. However, the information available on the association between Lp(a) levels and mitral valve disease is limited and controversial. The main objective of the present study was to assess the association between Lp(a) levels and mitral valve disease.

DATA SYNTHESIS

This systematic review was performed according to PRISMA guidelines (PROSPERO CRD42022379044). A literature search was performed to detect studies that evaluated the association between Lp(a) levels or single-nucleotide polymorphisms (SNPs) related to high levels of Lp(a) and mitral valve disease, including mitral valve calcification and valve dysfunction. Eight studies including 1,011,520 individuals were considered eligible for this research. The studies that evaluated the association between Lp(a) levels and prevalent mitral valve calcification found predominantly positive results. Similar findings were reported in two studies that evaluated the SNPs related to high levels of Lp(a). Only two studies evaluated the association of Lp(a) and mitral valve dysfunction, showing contradictory results.

CONCLUSIONS

This research showed disparate results regarding the association between Lp(a) levels and mitral valve disease. The association between Lp(a) levels and mitral valve calcification seems more robust and is in line with the findings already demonstrated in aortic valve disease. New studies should be developed to clarify this topic.

A qualitative improvement program for minimally invasive mitral surgery: technical advancements ameliorate outcome and operative times

OBJECTIVES

Minimally invasive mitral valve surgery (MIMVS) has evolved over the last 2 decades. The aim of the study was to identify the impact of era and technical improvements on perioperative outcome after MIMVS.

METHODS

A tota of 1000 patients (mean age: 60.8 ± 12.7 years, 60.3% male) underwent video-assisted or totally endoscopic MIMVS between 2001 and 2020 in a single institution. Three technical modalities were introduced during the observed period: (i) 3D visualization, (ii) use of premeasured artificial chordae (PTFE loops) and (iii) preoperative CT scans. Comparisons were made before and after the introduction of technical improvements.

RESULTS

A total of 741 patients underwent isolated mitral valve (MV) procedure, whereas 259 received concomitant procedures. These consisted of tricuspid valve repair (208), left atrium ablation (145) and persistent foramen ovale or atrial septum defect (ASD) closure (172). The aetiology was degenerative in 738 (73.8%) patients and functional in 101 patients (10.1%). A total of 900 patients received MV repair (90%), and 100 patients (10%) underwent MV replacement. Perioperative survival was 99.1%, and periprocedural success 93.5% with a periprocedural safety of 96.3%. Improvement in periprocedural safety attributed to the lower rates of postoperative low output (P = 0.025) and less reoperations for bleeding (P < 0.001). 3D visualization improved cross-clamp (P = 0.001) but not cardiopulmonary bypass times. The use of loops and preoperative CT scan both had no impact on periprocedural success or safety but improved cardiopulmonary bypass and cross-clamp times (both P < 0.001).

CONCLUSIONS

Increased surgical experience improves safety in MIMVS. Technical improvements are related to increased operative success and decreased operative times in patients undergoing MIMVS.

One-Year Healthcare Utilization and Expenditures Among Patients with Clinically Significant Mitral Regurgitation in Taiwan

INTRODUCTION

Mitral regurgitation (MR) is characterized by systolic blood flow reversal from the left ventricle to the left atrium. A 2019 study indicated that in the USA, clinically significant MR (sMR) is associated with a substantial healthcare cost burden. In Taiwan, few data are available to describe the clinical characteristics, treatment patterns, and economic burden of patients with sMR.

METHODS

Using the National Health Insurance Research Database (NHIRD), a national, detailed claims database of all 23 million residents of Taiwan, we conducted a retrospective cohort study to identify patients with sMR and quantify the impact of the disease on Taiwan's healthcare system. We classified patients with sMR into three cohorts based on disease etiology: functional MR (sFMR), degenerative MR (sDMR), and uncharacterized MR (sUMR).

RESULTS

We compared patient characteristics across cohorts and estimated attributable healthcare utilization and costs during the 12-month follow-up period. Our research shows that in Taiwan, patients with sFMR were older, sicker, and presented at casualty (emergency department) more frequently than those with sDMR and sUMR. Meanwhile, patients with sDMR had the highest 12-month healthcare expenditures across the cohorts.

CONCLUSION

These findings are inconsistent with what has been shown in the USA, which warrants further investigation.

The Clinical Profile and Natural History of Patients Who Fail Screening for Transcatheter Mitral Valve Replacement: Rationale and Design of the Prospective Multicenter Mitral Valve Screening Survey (MVSS)

Mitral valve disease is insidious and associated with a decreased quality of life and survival over time. Despite surgery being the standard of care, many patients are at prohibitive surgical risk. Furthermore, a substantial proportion of patients with symptomatic mitral valve disease fail stringent screening criteria for transcatheter mitral valve replacement (TMVR). The natural history of patients who fail screening is not well-characterized, and data are limited on the reasons for screen failure in this population. The Mitral Valve Screening Survey (MVSS) seeks to detail the clinical profile and natural history of patients who fail screening for TMVR. The MVSS is a prospective, multicenter registry enrolling up to 1000 consecutive subjects who, after screening for TMVR, are deemed not to be candidates. Subjects will be followed for 30 days after failing screening for TMVR and annually for up to 5 years with clinical evaluations. The primary study endpoint of the MVSS registry is all-cause mortality at 1 year. Additional secondary endpoints include all-cause mortality, hospitalizations, subsequent mitral valve intervention (transcatheter or surgical), reason for screen failure, and quality-of-life assessments at 30 days and annually up to 5 years of follow-up. The MVSS registry is the first prospective multicenter study to characterize the clinical and anatomical profile of patients who fail screening for TMVR while providing longitudinal clarification on the natural history and outcomes of these patients. CLINICAL TRIAL REGISTRATION: Mitral Valve Screening Survey (MVSS), https://clinicaltrials.gov/ct2/show/NCT04736667, NCT04736667.

The influence of renal disease on outcomes and cardiac remodeling following surgical mitral valve replacement

OBJECTIVES

Chronic kidney disease (CKD) is increasingly prevalent in patients undergoing mitral valve replacement (MVR). While CKD is known to result in suboptimal outcomes for patients with mitral valve disease, there is limited literature evaluating the long-term outcomes and cardiac remodeling of patients with CKD undergoing MVR. We present the first analysis coupling long-term outcomes of combined morbidity, mortality, and cardiac remodeling post-MVR in patients with CKD.

METHODS

Patients with varying degrees of CKD undergoing MVR from 2004 to 2018 were compared. Patients were grouped by estimated glomerular filtration rate (eGFR) > 90 mL/min/1.73m² (n = 109), 60-89 mL/min/1.73m² (450), 30-59 mL/min/1.73m² (449), < 30 mL/min/1.73m² (60). The primary outcome was mortality. Secondary outcomes included measures of postoperative morbidity and cardiac remodeling.

RESULTS

One-year mortality was significantly increased in patients with eGFR < 30 (p = 0.023). Mortality at 7 years was significantly increased in patients with eGFR < 30 mL/min/1.73m² (p < 0.001). Multivariable regression analysis of 7-year all-cause mortality indicated an eGFR of 15 mL/min/1.73m² (HR 4.03, 95% CI 2.54-6.40) and 30 mL/min/1.73m² (HR 2.17 95% CI 1.55-3.05) were predictive of increased mortality. Reduced eGFR predicted the development of postoperative sepsis (p = 0.002), but not other morbidities. Positive cardiac remodeling of the left ventricle, left atrium, and valve gradients were identified postoperatively for patients with eGFR > 30 mL/min/1.73m² while patients with eGFR < 30 mL/min/1.73m² did not experience the same changes.

CONCLUSIONS

CKD is predictive of inferior clinical and echocardiographic outcomes in patients undergoing MVR and consequently requires careful preoperative consideration and planning. Further investigation into optimizing the postoperative outcomes of this patient population is necessary.

Off-label transapical beating-heart transcatheter mitral valve replacement in severe mitral annular calcification

The recent CE mark approval of a novel transapical transcatheter beating-heart replacement system, anchored by an apical pad, expanded the therapeutic options for patients with a significantly diseased mitral valve who are not eligible for conventional surgery. However, this self-expandable bioprosthesis is-despite promising data from the first European real-world experience-not approved for patients with severe mitral annular calcification. In this video tutorial, we provide a step-by-step description of an off-label transapical mitral valve replacement in a patient with severe degenerative mitral valve disease and limited alternative treatment options.

Percutaneous transseptal transcatheter mitral valve-in-valve implantation under endovascular cerebral protection

Various interventional and minimally invasive surgical approaches are currently available for the treatment of mitral valve pathologies. However, only a few of these options are applicable in patients with previously operated on mitral valves. In this case report, we provide detailed insight into the step-by-step guidance of a percutaneous transseptal transcatheter mitral valve-in-valve implant under cerebral protection in a patient with a deteriorated surgically implanted mitral bioprosthesis.

Postdischarge-to-30-Day Mortality Among Patients Receiving MitraClip: A Systematic Review and Meta-Analysis

Background

MitraClip (MC) implantation is the recommended treatment for severe symptomatic mitral regurgitation in patients not responding to medical therapy and at prohibitive surgical risk. It is important to quantify immediate mortality during postdischarge-to-30-day period so as to improve the procedural outcomes. Hence, we aim to identify the incidence of postdischarge-to-30-day mortality and its associated predictors using the technique of meta-analysis.

Methods

We searched Medline, Embase, and Cochrane CENTRAL databases from inception until July 3, 2019 for studies reporting mortality prior to discharge, at 30 days and 1 year after MC implantation. The primary outcome was postdischarge-to-30-day all-cause mortality.

Results

Of 2394 references, 15 studies enrolling 7498 patients were included. Random effects analysis showed that all-cause cumulative inpatient, 30-day, and 1-year mortality was 2.40% (2.08, 2.77; I² = 0%), 4.31% (3.64, 5.09, I² = 41.9%), and 20.71% (18.32; 23.33, I² = 81.5%), respectively. The postdischarge-to-30-day mortality was 1.70% (95% confidence interval: 1.0, 2.70; I² = 84%). A total of 71.50% of deaths (95% confidence interval: 36.80-91.50, I² = 63%) in the postdischarge-to-30-day period were due to cardiac etiology. On meta-regression, pre-MC left ventricular ejection fraction (p = 0.003), Log.Euroscore (p = 0.047), Society of Thoracic Surgeons Predicted Risk of Mortality (p < 0.001), and prolonged ventilation >48 ​hours (p < 0.001) were found to be its significant predictors.

Conclusions

Our meta-analysis reports an additional mortality of ∼2% immediately after MC implantation during the postdischarge-to-30-day period. Majority of deaths occurred due to cardiac causes. Pre-MC left ventricular ejection fraction, Log.Euroscore, Society of Thoracic Surgeons Predicted Risk of Mortality score, and prolonged ventilation were found to be its significant predictors. Further studies are needed to better understand the causes of this early mortality to maximize benefits of this important therapy.

Large left atrial thrombus resection in a patient in sinus rhythm without mitral valve disease: A case report

Introduction

Left atrial (LA) ball thrombi are often associated with atrial fibrillation (AF) and mitral valve disease (MVD). Differentiating between thrombi and LA tumors can be challenging.

Presentation of a case

A 63-year-old man with a prior mesh insertion for abdominal incisional hernia was admitted with fever. He was diagnosed with an abdominal mesh-related infection requiring surgical debridement. Preoperative transthoracic echocardiography revealed a 39-mm smooth mass in the LA adherent to the atrial septum. The mass was suspected to be a cardiac tumor based on the morphology. The patient underwent mass resection. Pathophysiology revealed that the mass was a thrombus, necessitating anticoagulation therapy. No recurrence of thrombus formation was reported.

Discussion

In this case, a plausible factor causing the thrombus formation is the chronic mesh. Since LA thrombi can become free-floating or grow rapidly, early surgical intervention is essential to prevent thrombotic events or sudden death.

Conclusion

An LA thrombus should be included in the differential diagnosis when an LA mass is detected. Prompt surgical resection prevents thrombotic events and improves patient outcomes.

•

Causes of left atrial thrombus include mitral valve disease and atrial fibrillation.

•

Left atrial thrombi can be difficult to differentiate from left atrial tumors.

•

Large left atrial thrombi can become free-floating or grow rapidly.

•

For large left atrial thrombi, prompt surgery is required.

Cardiac involvement in Behçet disease presenting as non-bacterial thrombotic endocarditis: A case report

Behçet disease (BD) is a form of widespread vasculitis that involves both arteries and veins. Cardiac involvement in BD is exceedingly rare and can present as a form of non-bacterial- thrombotic-endocarditis (NBTE). A 54-year-old man with Behçet disease was admitted to our hospital after presenting with abdominal pain and fever. He had been recently discharged from a hospital in another country with the diagnosis of infective endocarditis of the mitral valve and mycotic embolization to the superior mesenteric artery. At presentation, oral and genital ulcers were present, raising the suspicion of a flare of BD. Transesophageal echocardiography showed a small vegetation on the anterior leaflet of the mitral valve. Blood cultures results were negative. Computed tomography of the abdomen showed extensive inferior vena cava thrombosis. The aneurysm and thrombotic phenomena were interpreted as related to BD: the vegetation on the mitral valve was diagnosed as NBTE of which BD is a recognized cause. With corticosteroid and anticoagulant therapy, the patient's symptoms steadily improved. NBTE is a rare manifestation of BD; differential diagnosis with infective endocarditis can be challenging and should be focused on identifying predisposing conditions. The mainstay of treatment in NBTE is medical therapy with anticoagulation and treatment of the underlying disease. <Learning objective: Cardiac involvement in the setting of Behçet Disease (BD) is rare and several different manifestations are described (intracardiac thrombus, non-infective endocarditis, myocarditis, pericarditis, endomyocardial fibrosis, coronary arteritis). Non-bacterial thrombotic endocarditis (NBTE) is also a rare finding which can happen in the setting of BD. Its prevalence is unknown and evidence is derived only from scarce case reports.The role of BD as a potential cause of NBTE must be acknowledged to avoid potential misdiagnosis.>.

Transcatheter mitral valve interventions

While there are dozens of novel transcatheter mitral devices in various stages of development, they remain years away from FDA approval. The existing approved transcatheter mitral interventions-transcatheter edge to edge repair for primary and secondary mitral regurgitations and transcatheter mitral valve-in-valve and valve-in-ring procedures for failing surgical prostheses-have seen a marked increase in both use and published data over the past several years. Transcatheter edge to edge repair with MitraClip has revolutionized the management of functional mitral regurgitation in heart failure with demonstrated reductions in mortality and heart failure hospitalization and is an appropriate option for patients with primary mitral regurgitation at high or prohibitive surgical risk. In patients with failing surgical mitral prostheses transcatheter mitral valve-in-valve and valve-in-ring procedures are an appealing alternative to repeat mitral valve surgery. Existing data and relevant concerns for these procedures are discussed herein.

The effect of treatment with pimobendan in dogs with preclinical mitral valve disease - a placebo-controlled double-blinded crossover study

Background

Pimobendan is a widely used medication for the treatment of dogs with congestive heart failure (CHF) and preclinical degenerative mitral valve disease (DMVD) with cardiomegaly. The benefit of a treatment in dogs with preclinical DMVD but without cardiomegaly has not yet been elucidated. Some positive effects concerning life quality and a decrease in cardiac biomarkers could be verified. This study aimed to further investigate these results using a placebo-controlled double-blinded crossover design. Out of a total of 15 dogs, eight were allocated to sequence-group AB, in which dogs received pimobendan (A) during the first treatment period and placebo (B) during the second period. Accordingly, sequence-group BA was treated first with placebo followed by pimobendan. Each treatment period lasted six months and included a baseline investigation and follow-ups after 90 and 180 days. The investigations included a questionnaire completed by the owners, echocardiographic examination, and measurements of NT-proBNP, cTnI and lactate before and after a standardised submaximal exercise test.

Results

NT-proBNP values decreased significantly during the treatment period with pimobendan, and the post-exercise increase was attenuated at day 180. No significant treatment effects could be verified for cTnI and lactate, neither pre- nor post-exercise. Left ventricular size decreased under treatment, whereas no significant changes in left atrial size were detected. The owners described their dogs under treatment with pimobendan as being more active at day 90 (11/15) and day 180 (12/15). Those animals treated with placebo were described as being more active at day 90 (2/15) and day 180 (5/15).

Conclusions

Pimobendan had reducing effects on the concentrations of pre- and post-exercise cardiac biomarkers and the size of the left ventricle in dogs with DMVD ACVIM B1. Exercise testing in addition to an assessment of cardiac biomarkers might improve the decision when to initiate pimobendan treatment in dogs with DMVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03014-5.

Is this the beginning of end for warfarin in bioprosthetic mitral valve recipients with atrial fibrillation? - New insights from RIVER trial

Novel oral anticoagulants, with dabigatran in particular have failed in their quest to replace the traditional anticoagulation in the form of vitamin K antagonist in patients with mechanical valvular implants. However, the same had not been tried in bioprosthetic valve recipients until recently in a large trial where rivaroxaban was found to be non-inferior to warfarin on head-to-head basis. This commentary discusses the various aspects related to oral anticoagulation in bioprosthetic valve recipients in the light of recent clinical evidence.

Alterations in Intracardiac Flow Patterns Affect Mitral Leaflets Dynamics in a Model of Ischemic Mitral Regurgitation

PURPOSE

This study was to evaluate the effects of ischemic mitral regurgitation (IMR) on vortex formation and leaflet dynamics using an established porcine infarct model of IMR.

METHODS

Using direct coronary ligation, five animals were subjected to a posterolateral myocardial infarction (MI) followed by an MRI at 12-weeks post MI. MR imaging consisted of 4D time-resolved left ventricular (LV) flow, full coverage 2D LV cine, and high resolution 2D cine of mitral valve dynamics. Five additional naïve animals underwent identical imaging protocols to serve as controls. Image analysis was performed to obtain mitral transvalvular flows as well as LV volumes throughout the cardiac cycle. In addition, anterior to posterior mid-leaflet tip distances were measured throughout the cardiac cycle for determination of temporal leaflet dynamics.

RESULTS

It was found IMR caused asymmetric vortex ring formation with the anterior vortex having a lower vorticity relative to its posterior counterpart. In contrast, normal ventricles create symmetric and tightly curled vortices in the basal chamber just underneath the mitral leaflets which conserve kinetic energy and aid in effective ejection. IMR animals were also evaluated for leaflet separation and were found to have a greater leaflet opening and achieved peak vorticity and peak leaflet opening later than control animals.

CONCLUSION

In conclusion, this study shows the effects that altered vortex formation, due to IMR, can have on ventricular filling and leaflet dynamics. These findings have important implications for understanding blood flow through the dilated heart and how ring annuloplasty and volume reduction interventions may influence mitral valve dynamics.

The role of robotic technology in minimally invasive surgery for mitral valve disease

INTRODUCTION

Robotic mitral valve surgery has developed for more than 20 years. The main purpose of robotic assistance is to use multiwristed instruments for surgical endothoracic maneuvers on the mitral valve without opening the chest. The surgeon controls the instruments remotely from a console but is virtually immersed into the operative field.

AREAS COVERED

This review outlines indications and contraindication for the procedure. Intra- and postoperative results as available in the literature are reported. Further areas focus on the technological development, advances in surgical techniques, training methods, and learning curves. Finally we give an outlook on the potential future of this operation.

EXPERT OPINION

Robotic assistance allows for the surgically least invasive form of mitral valve operations. All variations of robotic mitral valve repair and replacement are feasible and indications have recently been broadened. Improved dexterity of instrumentation, 3D and HD vision, introduction of a robotic left atrial retractor, and adjunct technology enable most complex forms of minimally invasive mitral valve interventions through ports on the patient's right chest wall. Application of robotics results in significantly reduced surgical trauma while maintaining safety and outcome standards in mitral valve surgery.

Sinus rhythm voltage fingerprinting in patients with mitral valve disease using a high-density epicardial mapping approach

Aims

Unipolar voltage (UV) mapping is increasingly used for guiding ablative therapy of atrial fibrillation (AF) as unipolar electrograms (U-EGMs) are independent of electrode orientation and atrial wavefront direction. This study was aimed at constructing individual, high-resolution sinus rhythm (SR) UV fingerprints to identify low-voltage areas and study the effect of AF episodes in patients with mitral valve disease (MVD).

Methods and results

Intra-operative epicardial mapping (interelectrode distance 2 mm) of the right and left atrium, Bachmann’s bundle (BB), and pulmonary vein area was performed in 67 patients (27 male, 67 ± 11 years) with or without a history of paroxysmal AF (PAF). In all patients, there were considerable regional variations in voltages. UVs at BB were lower in patients with PAF compared with those without [no AF: 4.94 (3.56–5.98) mV, PAF: 3.30 (2.25–4.57) mV, P = 0.006]. A larger number of low-voltage potentials were recorded at BB in the PAF group [no AF: 2.13 (0.52–7.68) %, PAF: 12.86 (3.18–23.59) %, P = 0.001]. In addition, areas with low-voltage potentials were present in all patients, yet we did not find any predilection sites for low-voltage potentials to occur.

Conclusion

Even in SR, advanced atrial remodelling in MVD patients shows marked inter-individual and regional variation. Low UVs are even present during SR in patients without a history of AF indicating that low UVs should carefully be used as target sites for ablative therapy.

Classification of sinus rhythm single potential morphology in patients with mitral valve disease

Aims

The morphology of unipolar single potentials (SPs) contains information on intra-atrial conduction disorders and possibly the substrate underlying atrial fibrillation (AF). This study examined the impact of AF episodes on features of SP morphology during sinus rhythm (SR) in patients with mitral valve disease.

Methods and results

Intraoperative epicardial mapping (interelectrode distance 2 mm) of the right and left atrium (RA, LA), Bachmann’s bundle (BB), and pulmonary vein area (PVA) was performed in 67 patients (27 male, 67 ± 11 years) with or without a history of paroxysmal AF (PAF). Unipolar SPs were classified according to their differences in relative R- and S-wave amplitude ratios. A clear predominance of S-waves was observed at BB and the RA in both the no AF and PAF groups (BB 88.8% vs. 85.9%, RA 92.1% vs. 85.1%, respectively). Potential voltages at the RA, BB, and PVA were significantly lower in the PAF group (P < 0.001 for each) and were mainly determined by the size of the S-waves amplitudes. The largest difference in S-wave amplitudes was found at BB; the S-wave amplitude was lower in the PAF group [4.08 (2.45–6.13) mV vs. 2.94 (1.40–4.75) mV; P < 0.001]. In addition, conduction velocity (CV) at BB was lower as well [0.97 (0.70–1.21) m/s vs. 0.89 (0.62–1.16) m/s, P < 0.001].

Conclusion

Though excitation of the atria during SR is heterogeneously disrupted, a history of AF is characterized by decreased SP amplitudes at BB due to loss of S-wave amplitudes and decreased CV. This suggests that SP morphology could provide additional information on wavefront propagation.

Effect of a dedicated mitral heart team compared to a general heart team on survival: a retrospective, comparative, non-randomized interventional cohort study based on prospectively registered data

 

OBJECTIVES

Although in both the US and European guidelines the 'heart team approach' is a class I recommendation, supporting evidence is still lacking. Therefore, we sought to provide comparative survival data of patients with mitral valve disease referred to the general and the dedicated heart team.

METHODS

In this retrospective cohort, patients evaluated for mitral valve disease by a general heart team (2009-2014) and a dedicated mitral valve heart team (2014-2018) were included. Decision-making was recorded prospectively in heart team electronic forms. The end point was overall survival from decision of the heart team.

RESULTS

In total, 1145 patients were included of whom 641 (56%) were discussed by dedicated heart team and 504 (44%) by general heart team. At 5 years, survival probability was 0.74 [95% confidence interval (CI) 0.68-0.79] for the dedicated heart team group compared to 0.70 (95% CI 0.66-0.74, P = 0.040) for the general heart team. Relative risk of mortality adjusted for EuroSCORE II, treatment groups (surgical, transcatheter and non-intervention), mitral valve pathology (degenerative, functional, rheumatic and others) and 13 other baseline characteristics for patients in the dedicated heart team was 29% lower [hazard ratio (HR) 0.71, 95% CI 0.54-0.95; P = 0.019] than for the general heart team. The adjusted relative risk of mortality was 61% lower for patients following the advice of the heart team (HR 0.39, 95% CI 0.25-0.62; P < 0.001) and 43% lower for patients following the advice of the general heart team (HR 0.57, 95% CI 0.37-0.87; P = 0.010) compared to those who did not follow the advice of the heart team.

CONCLUSIONS

In this retrospective cohort, patients treated for mitral valve disease based on a dedicated heart team decision have significantly higher survival independent of the allocated treatment, mitral valve pathology and baseline characteristics.

Cumulative sum analysis for the learning curve of minimally invasive mitral valve repair

Minimally invasive mitral valve repair, recently, has become an alternative procedure to conventional mitral valve surgery, given its clinical benefits. Understanding the learning curve of a new procedure is important prior to its introduction. This study aimed to evaluate the learning curve for minimally invasive mitral valve repair and safety during the start-up period. The first 100 consecutive patients who underwent isolated minimally invasive mitral valve repair for mitral valve regurgitation were evaluated. The procedure was performed by a single surgeon at a single institution. Calculated cumulative sum analysis and cubic spline curve analysis were performed to evaluate the learning curves for the total procedure (TP), extracorporeal circulation (ECC), and aortic cross-clamping (ACC) times. ACC time was affected by the complexity of individual mitral valve repair; therefore, we analyzed the TP minus ACC (TP-ACC) time as a true learning curve by subtracting the ACC time from the TP time to exclude the difference of the complexity. Additionally, the operative outcome was assessed. Overall, the average TP, ECC, ACC, TP-ACC times were 211 ± 41, 133 ± 35, 108 ± 31, and 104 ± 4.9 min, respectively. All cubic spline curves depicted a decreasing trend, and improvements in TP, ECC, and ACC times were observed after 56 cases, while those of the TP-ACC time were observed after 68 cases. None of the patients experienced hospital mortality, reoperation for bleeding, respiratory failure, cerebral infarction with a disability, or recurrence of mitral valve regurgitation. Acute renal failure occurred in one patient. In conclusion, minimally invasive mitral valve repair can be introduced safely and provide a favorable outcome. However, a learning curve exists for the operative time factors. Approximately 60 operations are required to achieve a consistent operative time.

Assessment of right ventricular systolic function by two dimensional speckle tracking echocardiography in rheumatic mitral valve disease

We assessed the Right Ventricular (RV) systolic function using two dimensional (2D) speckle tracking echocardiography (STE) in Mitral valve disease before and after intervention. 90 patients divided into 3 groups of Mitral stenosis [MS], Mitral regurgitation [MR] and MS with MR were the study subjects. All the patients were subjected to conventional echocardiography and measurement of Right ventricular global longitudinal strain (RVGLS). Prior to intervention, subjects who demonstrated normal RV function by conventional methods, it was found that RVGLS was impaired significantly in the MS and MS with MR groups but normal in the MR group. After intervention, the RVGLS improved significantly in the MS group but not in the other groups. Right ventricular systolic pressure (RVSP) had a significant negative correlation to RVGLS in all 3 groups.

Systematic quantification of histologic ventricular fibrosis in isolated mitral valve prolapse and sudden cardiac death

BACKGROUND

Cardiac fibrosis in mitral valve prolapse (MVP) is implicated in the development of sudden cardiac death (SCD); however, the pattern remains poorly characterized.

OBJECTIVE

The purpose of this study was to systematically quantify left and right ventricular fibrosis in individuals with isolated MVP and SCD (iMVP-SCD), whereby other potential causes of death are excluded, compared to a control cohort.

METHODS

Individuals with iMVP-SCD were identified from the Victorian Institute of Forensic Medicine, Australia, and matched for age, sex, and body mass index to control cases with noncardiac death. Cardiac tissue sections were analyzed to determine collagen deposition in the left ventricular free wall (anterior, lateral, and posterior portions), interventricular septum, and right ventricle. Within the iMVP-SCD cases, the endocardial-to-epicardial distribution of fibrosis within the left ventricle was specifically characterized.

RESULTS

Seventeen cases with iMVP-SCD were matched 1:1 with 17 controls, yielding 149 samples and 1788 histologic regions. The iMVP-SCD group had increased left ventricular (anterior, lateral, and posterior; all P <.001) and interventricular septum fibrosis (P <.001), but similar amounts of right ventricular fibrosis (P = .62) compared to controls. In iMVP-SCD, left ventricular fibrosis was significantly higher in the lateral and posterior walls compared to the anterior wall and interventricular septum (all P <.001). Within the lateral and posterior walls, iMVP-SCD cases had a significant endocardial-to-epicardial gradient of cardiac fibrosis (P <.01) similar to other known conditions that cause cardiac remodeling.

CONCLUSION

Our study indicates that nonuniform left ventricular remodeling with both localized and generalized left ventricular fibrosis is important in the pathogenesis of SCD in individuals with MVP.

Sex-Based Differences in Coronary and Structural Percutaneous Interventions

In the current state of interventional cardiology, the ability to offer advanced therapies to patients who historically were not surgical candidates has grown exponentially in the last few decades. As therapies have expanded in complex coronary and structural interventions, the nuances of treating certain populations have emerged. In particular, the role of sex-based anatomic and outcome differences has been increasingly recognized. As guidelines for cardiovascular prevention and treatment for certain conditions may vary by sex, therapeutic interventions in the structural and percutaneous coronary areas may also vary. In this review, we aim to discuss these differences, the current literature available on these topics, and areas of focus for the future.

MitraClip or Ventricular Assist Device?

The patient was a 59-year-old female with advanced heart failure and severe functional mitral regurgitation who was classified as INTERMACS profile 4 with repeated hospitalizations despite guideline-directed medical therapy. She was also listed for heart transplantation. After comparing the two major therapeutic strategies: (1) durable left ventricular assist device (LVAD) implantation and (2) percutaneous MitraClip procedure (Abbott Vascular, Abbott Park, IL, USA), we eventually decided to proceed with MitraClip, given her relatively lower B-type natriuretic peptide, lower MAGGIC Heart Failure risk score, and higher predicted survival without LVAD. The post-procedural course was favorable without any comorbidities or worsening of heart failure for 10 months. A diagnostic paradigm to guide which strategy to choose (LVAD or MitraClip) for patients with advanced heart failure and functional mitral regurgitation should be constructed.

Case report: Buddy wire technique to facilitate atrial septal crossing during transcatheter transseptal mitral valve implantation

Background

Transcatheter mitral valve-in-valve implantation (MVIV) has emerged as a viable treatment option in patients at high risk for surgery. Occasionally, despite appropriate puncture location and adequate dilation, difficulty is encountered in advancing the transcatheter heart valve across interatrial septum.

Case summary

We describe a case of a 79-year-old woman with severe chronic obstructive pulmonary disease (COPD), prior surgical bioprosthetic aortic and mitral valve replacement implanted in 2007, atrial fibrillation, and Group II pulmonary hypertension who presented with progressively worsening heart failure symptoms secondary to severe bioprosthetic mitral valve stenosis and moderate-severe mitral regurgitation. Her symptoms had worsened over several months, with multiple admissions at other institutions with treatment for both COPD exacerbation and heart failure. Transoesophageal echocardiogram demonstrated preserved ejection fraction, normal functioning aortic valve, and dysfunctional mitral prosthesis with severe stenosis (mean gradient 13 mmHg) and moderate-severe regurgitation. After a multi-disciplinary heart team discussion, the patient underwent a transcatheter MVIV implantation. During the case, inability in advancing the transcatheter heart valve (THV) across interatrial septum despite adequate septal balloon pre-dilation was successfully managed with the support of a stiff ‘buddy wire’ anchored in the left upper pulmonary vein using the same septal puncture. The patient tolerated the procedure well and was discharged home.

Discussion

Operators should be aware of potential strategies to advance the THV when difficulty is encountered in crossing the atrial septum despite adequate septal preparation. One such strategy is the use of stiff ‘buddy wire’ for support which avoids the need for more aggressive septal dilatation.

Percutaneous mitral valve repair with MitraClip XTR for acute mitral regurgitation due to papillary muscle rupture

Papillary muscle rupture is an infrequent and highly morbid mechanical complication of acute myocardial infarction. Surgical repair or replacement is traditionally considered first-line therapy. However, many of these patients present in extremis with prohibitively high surgical risk. Repair of mitral regurgitation with the MitraClip device (Abbot Vascular, Menlo Park, CA, USA) is an established therapy to treat degenerative and functional mitral regurgitation. We present a case of successful repair of severe mitral regurgitation due to papillary muscle rupture in the setting of acute myocardial infarction. A two-clip strategy resulted in mild residual mitral regurgitation with resolution of cardiogenic shock and refractory hypoxemia requiring veno-venous extracorporeal membrane oxygenation. Six-month follow-up echocardiogram identified durable results with mild mitral regurgitation and left ventricular ejection fraction of 63 %. Our case demonstrates that percutaneous mitral valve repair with MitraClip is a well-tolerated procedure that can provide acute and long-term benefit for patients with acute mitral regurgitation due to papillary muscle rupture who are at prohibitively high surgical risk. .

Association of transcatheter direct mitral annuloplasty with acute anatomic, haemodynamic, and clinical outcomes in severe mitral valve regurgitation

AIMS

Several approaches for transcatheter mitral valve repair for functional mitral valve regurgitation are established. Interventional direct annuloplasty is a novel trans-venous, trans-septal approach. While feasibility was proven recently, knowledge on its influence on cardiac dimensions, pressures, biomarkers, and clinical outcomes is sparse.

METHODS AND RESULTS

Patients consecutively treated with direct annuloplasty-only procedures between December 2015 and April 2018 were included in this monocentric analysis. Echocardiographic measurements, biomarker levels, clinical status [New York Heart Association (NYHA) class and 6 min walk test] were assessed at baseline, at discharge, and at a 30 day follow-up. Overall, 18 patients (in mean 77.0 ± 7.4 years, 44.4% women) with initially all high-grade mitral valve regurgitation (MR) were included in this study. Procedural success rate was high (94.4%) without severe complications. Direct annuloplasty resulted in MR-reduction (post-procedural-MR mild or no/trace: 72.2%) and the proportion of patients with severe dyspnoea (NYHA III/IV) was reduced (88.9% vs. 50%, P = 0.008). Clinical results were associated with a relevant diminution of left atrial volumes (-16.5%, P < 0.001) and cardiac pressures [left atrial pressure (-32.3%, P = 0.019) and systolic pulmonary arterial pressure (PAP, -15.8%, P = 0.025)]. Patients with lower baseline levels of PAP (P = 0.022) as well as elevated highly sensitive troponin (P = 0.034) were more likely to archive clinical benefit (improvement in NYHA class ≥1 grade) after 1 month, which could not be correlated with the grade of MR-reduction.

CONCLUSIONS

Transcatheter mitral valve repair by direct annuloplasty results in a relevant reduction of intracardiac pressures, left atrial volumes, dyspnoea, and MR. Lower PAP and higher troponin values at baseline could be associated to dyspnoea reduction.

Comparative pathology of human and canine myxomatous mitral valve degeneration: 5HT and TGF-β mechanisms

Myxomatous mitral valve degeneration (MMVD) is a leading cause of valve repair or replacement secondary to the production of mitral regurgitation, cardiac enlargement, systolic dysfunction, and heart failure. The pathophysiology of myxomatous mitral valve degeneration is complex and incompletely understood, but key features include activation and transformation of mitral valve (MV) valvular interstitial cells (VICs) into an active phenotype leading to remodeling of the extracellular matrix and compromise of the structural components of the mitral valve leaflets. Uncovering the mechanisms behind these events offers the potential for therapies to prevent, delay, or reverse myxomatous mitral valve degeneration. One such mechanism involves the neurotransmitter serotonin (5HT), which has been linked to development of valvulopathy in a variety of settings, including valvulopathy induced by serotonergic drugs, Serotonin-producing carcinoid tumors, and development of valvulopathy in laboratory animals exposed to high levels of serotonin. Similar to humans, the domestic dog also experiences naturally occurring myxomatous mitral valve degeneration, and in some breeds of dogs, the lifetime prevalence of myxomatous mitral valve degeneration reaches 100%. In dogs, myxomatous mitral valve degeneration has been associated with high serum serotonin, increased expression of serotonin-receptors, autocrine production of serotonin within the mitral valve leaflets, and downregulation of serotonin clearance mechanisms. One pathway closely associated with serotonin involves transforming growth factor beta (TGF-β) and the two pathways share a common ability to activate mitral valve valvular interstitial cells in both humans and dogs. Understanding the role of serotonin and transforming growth factor beta in myxomatous mitral valve degeneration gives rise to potential therapies, such as 5HT receptor (5HT-R) antagonists. The main purposes of this review are to highlight the commonalities between myxomatous mitral valve degeneration in humans and dogs, with specific regards to serotonin and transforming growth factor beta, and to champion the dog as a relevant and particularly valuable model of human disease that can accelerate development of novel therapies.

Dietary intervention reduces left atrial enlargement in dogs with early preclinical myxomatous mitral valve disease: a blinded randomized controlled study in 36 dogs

Background

Myxomatous mitral valve disease (MMVD), the most common naturally-occurring heart disease in dogs, is associated with alterations in energy metabolism, oxidative stress and inflammation. Energy deprivation plays a causal role in the development of heart failure. This study was designed to determine if a cardiac protection blend (CPB) of nutrients containing medium-chain triglycerides as an alternative energy source, fish oil to reduce inflammation, antioxidants, and other key nutrients important to cardiac health and function could slow or prevent MMVD progression. Nineteen dogs with early stage MMVD and 17 breed-, age-, and sex-matched healthy dogs were enrolled for a 6-month blinded, placebo-controlled study. Dogs in each cardiac health group were randomly assigned to either control diet (CON) or CPB-supplemented diet. Echocardiography was performed at baseline, 3 months and 6 months.

Results

No changes were found in healthy dogs. While MMVD-CON dogs had an average 10% increase over baseline in left atrial diameter (LAD) and left atrial to aortic root ratio (LA/Ao) at 6 months, MMVD-CPB dogs showed 3% decreases, resulting significant diet by time interactions (P = 0.037, P = 0.005, respectively). More MMVD-CON dogs progressed from stage B1 to B2 during the study. A positive correlation was found between 6-month changes in LAD and blood pressures in MMVD-CPB dogs (systolic: P = 0.050, diastolic: P = 0.035) but not MMVD-CON dogs.

Conclusions

Our results demonstrated efficacy of CPB-based dietary intervention in reducing LA size and mitral regurgitation, and in slowing or preventing the progression of early MMVD in dogs.

Heart to spine measurements to detect left atrial enlargement in dogs with mitral insufficiency

Background

Radiography is useful to determine left atrial (LA) size when echocardiography is not available. Recently, the authors have described Radiographic Left Atrial Dimension (RLAD) as a new radiographic measurement to assess LA size. The objective of this study was to assess the clinical usefulness of 2 new radiographic measurements to detect and quantify left atrial enlargement (LAE) compared to RLAD and using left atrium to aortic root (LA/Ao) ratio as gold standard. These new measurements, bronchus-to-spine (Br-Spine) and RLAD-to-spine (RLAD-Spine) may be more precise in cases were LA boundaries are not well defined. Fifty dogs, 25 with and 25 without LAE were recruited. Reference LA/Ao ratio was assessed by 2D echocardiography and LAE was considered if LA/Ao > 1.6. Br-spine was measured as a straight vertical line from the main stem bronchus to the ventral border of the vertebra situated immediately dorsal to the heart base. RLAD-Spine was measured from RLAD endpoint perpendicularly to spine. The correlation of RLAD, Br-Spine and RLAD-Spine methods with LA/Ao and their sensitivity and specificity for detecting LAE were calculated. Receiver Operating Characteristic (ROC) curves were used to estimate the optimal cut-off for each method.

Results

Correlations between Br-Spine, RLAD-Spine, RLAD and LA/Ao ratio were - 0.66, - 0.76 and 0.89 respectively (P < 0.001). Sensitivity at the optimal cut-off values for detecting LAE were 32.0, 64.0 and 96.0%, respectively. Specificity was 96.0% in all cases.

Conclusion

Br-Spine and RLAD-Spine were less sensitive radiographic measurements than RLAD in detecting LAE in dogs. Both Br-Spine and RLAD-Spine may not be good alternatives to RLAD.

Pulmonary hypertension and valvular heart disease

Pulmonary hypertension (PH) is an important contributor to morbidity and mortality in patients with left-sided heart disease, including valvular heart disease. In this context, elevated left atrial pressure primarily leads to the development of post-capillary PH. Despite the fact that repair of left-sided valvular heart disease by surgical or interventional approaches will improve PH, recent studies have highlighted that PH (pre- or post-interventional) remains an important predictor of long-term outcome. Here, we review the current knowledge on PH in valvular heart disease taking into account new hemodynamic PH definitions, and the distinction between post- and pre-capillary components of PH. A specific focus is on the precise characterization of hemodynamics and cardiopulmonary interaction, and on potential strategies for the management of residual PH after mitral or aortic valve interventions. In addition, we highlight the clinical significance of tricuspid regurgitation, which may occur as a primary condition or as a consequence of PH and right heart dilatation (functional). In this context, proper patient selection for potential tricuspid valve interventions is crucial. Finally, the article highlights gaps in evidence, and points toward future perspectives.

Heart valve operations associated with reduced risk of death from mitral valve disease but other operations associated with increased risk of death: a national population-based case-control study

Background

Mitral valve disease is the most common heart valve disease worldwide. Heart valve operation is the predominant treatment strategy for heart valve disease. This study analyzed the death risk from heart valve disease with respect to the frequency of heart valve operation and other operations in patients with mitral valve disease.

Materials and methods

We conducted a retrospective nationwide population-based case–control study using a claims dataset from Taiwan’s National Health Insurance Research Database. The case and control groups enrolled mitral valve disease patients from 2002 to 2013 who had either underwent an heart valve operation procedure or not, respectively. Conditional logistic regression was estimated the odds ratios (ORs) associated with various risk factors for heart valve operation-related death, including other operations and comorbidities.

Results

A total of 25,964 patients with mitral valve disease were recruited for the study and divided into heart valve operation (600 patients) and non-heart valve operation (25,364 patients) groups. After matching, a total of 1800 non-heart valve operation patients were selected for final analysis. Heart valve operation was associated with decreased risk of death (adjusted OR [aOR] 0.439), but operations related to other cardiovascular disease (CVD, aOR 3.691), respiratory conditions (aOR 3.210), and the urinary system (aOR 1.925) were associated with increased risk of death for patients with mitral valve disease. Patients with mitral valve disease and diabetes (aOR 1.505), chronic kidney disease (CKD, aOR 3.760), or emphysema (aOR 2.623) also had a higher risk of death. Patients who underwent more heart valve operations had a lower risk of death from mitral valve disease, but patients who underwent more other operations had a higher risk of death from mitral valve disease.

Conclusions

The death risk for patients with mitral valve disease patients could be lowered by more frequently performing heart valve operations. However, the risk of death is increased for patients with mitral valve disease who more frequently undergo other operations, chiefly those for other CVD system, respiratory conditions, and urinary system, or have comorbidities such as diabetes, chronic kidney disease, and emphysema.

Mitral valve leaflet repair with the new PASCAL system: early real-world data from a German multicentre experience

AIMS

To examine the clinical experience and practical use of the PASCAL transcatheter valve repair system (Edwards Lifesciences, Irvine, CA, USA) and to report some of the first clinical results.

METHODS AND RESULTS

A total of 18 consecutive patients with severe, symptomatic mitral regurgitation (MR) were included in this German multicentre registry. All patients underwent clinical, echocardiographic, and laboratory assessment prior to the PASCAL procedure and before hospital discharge. MR was classified as functional in 6 patients, degenerative in 2, and combined in 10. All except one received a single PASCAL implant. The preprocedural severe MR present in all patients was reduced: grade 0 in 4 (22.2%), grade I in 11 (61.1%), grade II in 3 (16.7%). The v-wave was significantly reduced from 31.7 ± 9.5 to 18 ± 7.7 mmHg (p < 0.001). Independent leaflet capture, performed in 4 (22.2%) of the patients, wide clasps, and the 10-mm central spacer are features of the PASCAL device to optimize mitral leaflet repair. There were no periprocedural complications.

CONCLUSION

PASCAL is a safe and effective mitral valve repair device for the treatment of severe MR. Device-specific features allow valve repair tailored to the individual anatomy of the underlying mitral pathology in each patient.

Left atrial mechanics in moderate mitral valve disease: earlier markers of damage

While the impairment of left atrial (LA) mechanics in mitral valve disease is well known, the exact onset of reservoir, conduit, and contractile dysfunction in mitral stenosis (MS) and mitral regurgitation (MR) remains unclear. We aimed to clarify the LA deformation mechanics in patients with moderate mitral valve disease. We conducted a prospective observational study of 80 patients with moderate isolated MR, 80 patients with moderate isolated MS, and 64 age-matched controls without mitral valve disease. Strain (ɛ) and strain rate (SR) on speckle tracking echocardiography were assessed as indicators of LA and right atrium (RA) reservoir (ɛsys, SRs), conduit (ɛe, SRe), and contractile (ɛa, SRa) functions. Conventional echocardiographic parameters of the left ventricle (LV) were also assessed. Comparisons were conducted according to mitral valve pathology (MR patients, MS patients, controls). The mean LV ejection fraction, end-diastolic diameter, and global longitudinal strain did not differ across the groups. The pulmonary artery systolic pressure, LA volume indexed to body surface area, and LA mechanics were significantly impaired in mitral valve disease (patients vs controls). While LA ɛ did not vary between MR and MS, MR patients had better LA SRs and SRe but worse SRa (p < 0.01). SRe > - 0.65% had higher specificity for MS, with an area under the curve of 0.85 (p < 0.01). RA mechanics were significantly impaired in mitral valve disease (patients vs controls) but did not vary significantly with disease pathology (MS vs MR). Patients with moderate mitral valve disease exhibit early and pathology-specific changes in the LA deformation mechanics, manifesting mainly as impaired contractile-phase SR in MR and impaired conduit-phase SR in MS. Our findings highlight SR as a potentially useful early marker of LA dysfunction in relation to mitral valve disease.

Effect of Pimobendan on NT-proBNP and c troponin I before and after a submaximal exercise test in dogs with preclinical mitral valve disease without cardiomegaly - a randomised, double-blinded trial

Background

Exercise testing in conjunction with measurement of cardiac biomarkers NT-proBNP and cTnI is a useful tool for monitoring the effect of treatment on cardiac patients. Administering Pimobendan in dogs with degenerative mitral valve disease (DMVD) and cardiomegaly results in delaying the onset of clinical symptoms and prolonging life. Its effect in dogs with DMVD without cardiomegaly has not been well examined. The aim of the current study was to investigate the effect of administering Pimobendan in dogs with DMVD without cardiomegaly using exercise testing in conjunction with measuring cardiac biomarkers in addition to echocardiography.

Twenty-one dogs with asymptomatic DMVD without echocardiographic signs of cardiomegaly participated in a randomised, double-blinded trial. Dogs were divided into a Pimobendan-group (n = 11) and a placebo-group (n = 10) in a double-blinded study design and underwent a standardised submaximal exercise test (SSET). One dog in the Pimobendan-group was retrospectively removed from the study after being diagnosed with Leishmaniosis. Cardiac biomarkers NT-proBNP and cTnI were measured before and after exercise. Follow-up appointments were performed at days 90 and 180.

Results

Dogs in the Pimobendan-group had significantly lower post-exercise NT-proBNP-levels after being administered Pimobendan than at the beginning of the study. They also had lower pre- and post-exercise-NT-proBNP-levels than those dogs in the placebo-group. There was neither a significant difference regarding the measured cTnI levels nor an increase in cTnI between the groups at any time.

Conclusions

Pimobendan lowers NT-proBNP in dogs with presymptomatic mitral valve disease without cardiomegaly before and after submaximal exercise. This indicates a reduction in cardiac wall stress. If dogs with asymptomatic DMVD without cardiomegaly benefit from treatment with Pimobendan (for example, through a longer survival time) warrants further investigation.

Urine 5-hydroxyindoleacetic acid in Cavalier King Charles spaniels with preclinical myxomatous mitral valve disease

Higher concentrations of circulating serotonin have been reported in Cavalier King Charles spaniels (CKCS) compared to other dog breeds. The CKCS is also a breed highly predisposed to myxomatous mitral valve disease (MMVD). The aim of this study was to determine urine concentrations of 5-hydroxyindoleacetic acid (5-HIAA), the major metabolite and excretion product of serotonin, in a population of CKCS with preclinical MMVD, and to evaluate whether urine 5-HIAA concentrations were associated with MMVD severity, dog characteristics, setting for urine sampling, platelet count, and serotonin concentration in serum and platelet-poor plasma (PPP). The study population consisted of 40 privately-owned CKCS (23 females; 17 males) with and without preclinical MMVD as follows: American College of Veterinary Internal Medicine (ACVIM) group A (n = 11), ACVIM group B1 (n = 21) and ACVIM group B2 (n = 8). Urine 5-HIAA concentrations were not significantly associated with preclinical MMVD disease, platelet count or circulating concentrations of serotonin (in serum and PPP; P > 0.05). Females had higher 5-HIAA concentrations than males in morning urine collected at home (females, 3.1 [2.9-3.7] μmol/mmol creatinine [median and quartiles]; males, 1.7 [1.2-2.2] μmol/mmol creatinine; P = 0.0002) and urine collected at the clinic (females, 3.5 [3.1-3.9] μmol/mmol creatinine; males, 1.6 [1.3-2.1] μmol/mmol creatinine; P < 0.0001). Five-HIAA concentrations in urine collected at home and at the clinic were significantly associated (P = 0.0004; r = 0.73), and higher concentrations were found in urine collected at the clinic (P = 0.013). Urine 5-HIAA concentration was influenced by sex and setting of urine sampling. Urine 5-HIAA concentration was not associated with MMVD severity or circulating concentrations of serotonin in CKCS with preclinical disease.

Unrecognized Cardiac Amyloidosis at the Time of Mitral Valve Surgery: Incidence and Outcomes

OBJECTIVE

It is increasingly recognized that cardiac amyloidosis can occur in patients with severe aortic stenosis undergoing both surgical and transcatheter valve replacements. We aimed to investigate whether unrecognized cardiac amyloidosis may also occur in patients with severe mitral valve disease undergoing surgery.

METHODS

The pathology department database at our center was retrospectively analyzed over a 10-year period for cases in which the mitral valve or another type of cardiac tissue removed at the time of mitral surgery demonstrated incidental amyloidosis. Clinical and echocardiographic variables were collected from the electronic medical record and the echocardiographic database.

RESULTS

Between 2007 and 2016, a total of 7,733 mitral valve surgical specimens were received. Of these, there were 15 cases in which the mitral valve, or another type of cardiac tissue removed at surgery, demonstrated incidentally detected amyloidosis. The most frequent comorbidities were hypertension (87%) and atrial fibrillation (80%); 13 patients (87%) underwent bioprosthetic mitral valve replacement, and 2 patients (13%) underwent mitral valve repair. Sites of amyloid deposition were the mitral valve (80%), left atrial appendage (33%), and subaortic tissue (7%); 14 patients (93%) had wild-type transthyretin amyloid. The mean duration of follow-up was 1,023 days (range: 29-2,811 days). There were no surgical complications in the follow-up period.

CONCLUSIONS

Over a 10-year period, incidentally detected cardiac amyloidosis occurred in 0.2% of the mitral valve surgical cases. The outcomes for these patients undergoing mitral valve surgery were excellent, with no complications or deaths attributable to surgery at a mean follow-up of 1,023 days.

Treatment of Functional Mitral Regurgitation with Transcatheter Edge-to-Edge Repair

Mitral valve regurgitation is a common valvular lesion affecting approximately 1 in 10 older adults, and it can be broadly categorized as degenerative or functional in etiology. Although transcatheter mitral valve repair with the MitraClip is currently approved for commercial treatment of severe degenerative mitral regurgitation, its role in patients with functional mitral regurgitation is evolving. Two recent pivotal trials have evaluated the effectiveness of the MitraClip device in those with severe functional mitral regurgitation. We review the concepts of edge-to-edge mitral valve repair and evidence regarding transcatheter edge-to-edge repair with MitraClip in patients with functional mitral regurgitation.

Left Ventricular Outflow Tract Obstruction: A Potential Obstacle for Transcatheter Mitral Valve Therapy

Transcatheter mitral valve replacement is the focus of much enthusiasm as the future of therapy for mitral valve disease. Despite technological advances, left ventricular outflow tract (LVOT) obstruction from the valve prosthesis remains an important issue. In this review the authors discuss the pathophysiology of LVOT obstruction in both the surgical and transcatheter experience, imaging evaluation preprocedure, outcomes to date, and therapeutic options.

Multidisciplinary decision-making in mitral valve disease: the mitral valve heart team

Background

Although decision-making using the heart-team approach is apparently intuitive and has a class I recommendation in most recent guidelines, supportive data is still lacking. The current study aims to demonstrate the individualised clinical pathway for mitral valve disease patients and to evaluate the outcome of all patients referred to the dedicated mitral valve heart team.

Methods

All patients who were evaluated for mitral valve pathology with or without concomitant cardiac disease between 1 January 2016 and 31 December 2016 were prospectively followed and included. Patients were evaluated, and a treatment strategy was determined by the dedicated mitral valve heart team.

Results

One hundred and fifty-eight patients were included; 67 patients were treated surgically (isolated and concomitant surgery), 20 by transcatheter interventions and 71 conservatively. Surgically treated patients had a higher 30-day mortality rate (4.4%), which decreased when specified to a dedicated surgeon (1.7%) and in primary, elective cases (0%). This was also observed for major adverse events within 30 days. Residual mitral regurgitation >grade 2 was more frequent in the catheter-based intervention group (23.5%) compared to the surgical group (4.8%).

Conclusion

In conclusion, the implementation of a multidisciplinary heart team for mitral valve disease is a valuable approach for the selection of patients for different treatment modalities. Our research group will focus on a future comparative study using historical cohorts to prove the potential superiority of the dedicated multidisciplinary heart-team approach.

A radiographic measurement of left atrial size in dogs

Background

The dimensions of the left atrium in cases with mitral regurgitation are an indirect measurement of its severity. The objective of this study was to evaluate the value of a new radiographic measurement, the radiographic left atrial dimension (RLAD), for detecting left atrial enlargement (LAE) in dogs. Thirty one dogs without LAE and 46 dogs with LAE were recruited in a prospective fashion. Reference left atrium dimension was measured by standard left atrium to aorta ratio (LA/Ao) by 2D echocardiography. LAE was considered if LA/Ao > 1.6. Left atrium dimension was then quantified on lateral radiographs by measuring RLAD. Vertebral heart size (VHS) was measured and RLAD was obtained by drawing a line bisecting the 90 degrees angle defined by the long and short cardiac axes lines of the VHS, up to the dorsal edge of the left atrium and comparing its length to T4’s vertebral body length. The correlation of VHS and RLAD methods with LA/Ao was estimated, as well as their sensitivity and specificity for detecting LAE. Receiver Operating Characteristic (ROC) curves were used to estimate the optimal decision criteria for each method.

Results

A positive correlation was observed between RLAD and LA/Ao (r = 0.82). RLAD’s sensitivity and specificity for detecting LAE when evaluated at the optimal cut-off value, 1.8 vertebrae, were 93.5 and 96.8% respectively. RLAD showed high reproducibility and repeatability.

Conclusion

RLAD appears to be a clinically useful radiographic measurement for evaluating left atrial dimensions. RLAD would provide clinicians with a simple and cost-effective tool for evaluating and monitoring LAE.

MitraClip Implantation in Younger Patients and Pediatric Populations: 19 Year-Old Patient with Multiple Comorbidities and a Prior Mitral Valve Annuloplasty

MitraClip is an effective treatment method for severe mitral regurgitation in high-risk populations in terms of reducing morbidity and frequency of hospitalizations. Efficacy and safety of MitraClip device in elderly population have been established, yet there are only 2 case reports of MitraClip implantation in the younger patients, who generally tend to have less surgical risk (Gorenflo et al.; Joffe et al., 2016). We describe a 19-year-old patient with severe mitral regurgitation with prior mitral valve annuloplasty and received MitraClip implantation due to high-surgical risk.

Predictors of mitral annulus enlargement? A real-time three-dimensional transesophageal study

BACKGROUND

Mitral annulus (MA) enlargement can be observed in various cardiac conditions but respective influence of left atrial (LA) and left ventricle (LV) size remained unclear.

METHODS

In 120 patients who underwent a clinically indicated 3D-transesophageal-echocardiography, 30 atrial fibrillation (AF), 30 secondary mitral regurgitation (SMR), 30 primary myxomatous mitral regurgitation (PMR) and 30 mitral stenosis (MS), we evaluated the association between MA area (MA-area) and LA volume (LAvol) measured using the biplane area-length method, end-diastolic (LVEDV) and end-systolic (LVESV) volumes measured using the biplane Simpson method. MA-area was measured based on 3D datasets using QLab10.

RESULTS

MA-area was correlated to LVEDV (r = 0.42, p < 0.0001), LVESV (r = 0.29, p = 0.001) but more markedly to LAvol (r = 0.62, p < 0.0001). Correlation between MA-area and LAvol was sustained in all subsets whereas MA-area was not correlated to LVEDV and LVESV in patients with SMR and with PMR (all p > 0.10). In multivariate analysis main predictors of MA-area were LAvol (p < 0.0001) and myxomatous etiology of MR (p = 0.0003) followed by LVEDV (p = 0.006) and LVESV (p = 0.02).

CONCLUSION

In a population of patients with a wide range of LA/LV size related to various conditions, LA volume and myxomatous MR etiology appeared as main predictors of MA size whereas LV size had a more modest influence.

Deceiving spindle cell sarcoma of the heart

Primary cardiac tumors are rare and when they occur, 75% are benign. Atrial myxomas having a good prognosis compromise 50% of all primary cardiac tumors. Only 25% of the primary cardiac tumors are malignant and 75% of these malignant tumors are sarcomas. Sarcomas often occur in young patients without any predisposing factors and tend to have very poor prognosis. We present an unfortunate case of a young female with high-grade spindle cell sarcoma. She was initially diagnosed to have mitral valve pathology and hypertrophic cardiomyopathy but confirmation of diagnosis was made only after a second operation and patient's demise.