Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years

Outcome of Patients With Both Moderate Aortic Stenosis and Moderate Mitral Stenosis

Aims

This study aimed to investigate the symptoms and prognosis of patients with both moderate aortic stenosis (AS) and mitral stenosis (MS).

Methods and Results

We studied 82 patients with moderate AS and MS diagnosed via transthoracic echocardiography. The patients had a mean age of 79 ± 13 years and 95% of patients had degenerative MS. Out of 82 patients, 34 (41%) had heart failure (HF) symptoms (New York Heart Association class ≥ Ⅱ) or a history of HF admission. Left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were independent determinants of HF symptoms. The median follow-up duration was 3.2 (interquartile range, 1.0-4.9) years and clinical events occurred in 48 (59%) patients, including death in 11 (13%) patients, aortic or mitral valve interventions in 22 (27%) patients, and HF hospitalization in 15 (18%) patients. The 5-year survival free of the combined endpoint of aortic or mitral valve interventions, HF hospitalization, or death was 19%. A multivariate predictor of clinical events was HF symptoms (hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.30-4.14; p = 0.0045). Kaplan-Meier survival at 5 years was 61% without intervention and HF symptoms were not associated with mortality.

Conclusions

Among patients with both moderate AS and MS, left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were strong determinants of HF symptoms. HF symptoms were independently predictive of clinical events.

Acute mitral regurgitation with and without acute heart failure

Acute severe mitral regurgitation (MR) is rare, but often leads to cardiogenic shock, pulmonary edema, or both. Most common causes of acute severe MR are chordae tendineae (CT) rupture, papillary muscle (PM) rupture, and infective endocarditis (IE). Mild to moderate MR is often seen in patients with acute myocardial infarction (AMI). CT rupture in patients with floppy mitral valve/mitral valve prolapse is the most common etiology of acute severe MR today. In IE, native or prosthetic valve damage can occur (leaflet perforation, ring detachment, other), as well as CT or PM rupture. Since the introduction of percutaneous revascularization in AMI, the incidence of PM rupture has substantially declined. In acute severe MR, the hemodynamic effects of the large regurgitant volume into the left atrium (LA) during left ventricular (LV) systole, and in turn back into the LV during diastole, are profound as the LV and LA have not had time to adapt to this additional volume. A rapid, but comprehensive evaluation of the patient with acute severe MR is essential in order to define the underline cause and apply appropriate management. Echocardiography with Doppler provides vital information related to the underlying pathology. Coronary arteriography should be performed in patients with an AMI to define coronary anatomy and need for revascularization. In acute severe MR, medical therapy should be used to stabilize the patient before intervention (surgery, transcatheter); mechanical support is often required. Diagnostic and therapeutic steps should be individualized, and a multi-disciplinary team approach should be utilized.

Prognostic value of forward flow indices in primary mitral regurgitation due to mitral valve prolapse

Background

Degenerative mitral regurgitation (DMR) due to mitral valve prolapse (MVP) is a common valve disease associated with significant morbidity and mortality. Timing for surgery is debated for asymptomatic patients without Class I indication, prompting the search for novel parameters of early left ventricular (LV) systolic dysfunction.

Aims

To evaluate the prognostic impact of preoperative forward flow indices on the occurrence of post-operative LV systolic dysfunction.

Methods

We retrospectively included all consecutive patients with severe DMR due to MVP who underwent mitral valve repair between 2014 and 2019. LVOT_TVI, forward stroke volume index, and forward LVEF were assessed as potential risk factors for LVEF <50% at 6 months post-operatively.

Results

A total of 198 patients were included: 154 patients (78%) were asymptomatic, and 46 patients (23%) had hypertension. The mean preoperative LVEF was 69 ± 9%. 35 patients (18%) had LVEF ≤ 60%, and 61 patients (31%) had LVESD ≥40 mm. The mean post-operative LVEF was 59 ± 9%, and 21 patients (11%) had post-operative LVEF<50%. Based on multivariable analysis, LVOT_TVI was the strongest independent predictor of post-operative LV dysfunction after adjustment for age, sex, symptoms, LVEF, LV end systolic diameter, atrial fibrillation and left atrial volume index (0.75 [0.62-0.91], p < 0.01). The best sensitivity (81%) and specificity (63%) was obtained with LVOTTVI ≤15 cm based on ROC curve analysis.

Conclusion

LVOT_TVI represents an independent marker of myocardial performance impairment in the presence of severe DMR. LVOT_TVI could be an earlier marker than traditional echo parameters and aids in the optimization of the timing of surgery.

Prosthetic Mitral Valve Thrombosis: A Complication Following Mitral Valve Surgery and Coronary Artery Bypass Graft Surgery

Mitral valve regurgitation is a common valvular defect that can lead to severe complications, requiring surgical intervention, often in the form of either mitral valve repair or replacement. This case report follows a 63-year-old male with multivessel coronary artery disease, who initially presented to the emergency department (ED) with a non-ST elevation myocardial infarction (NSTEMI) secondary to multivessel coronary artery disease with severe mitral regurgitation, and subsequently underwent coronary artery bypass grafting (CABG) with repair of the mitral valve. He was readmitted a month later with endocarditis of the mitral valve and underwent a reoperation with a bioprosthetic mitral valve replacement and massive reconstruction of the right ventricle, after which he failed to recover postoperatively. A repeat transesophageal echocardiogram (TEE) during his final chest washout procedure revealed echodensities suspicious for thrombi and, despite the team’s best efforts, the patient expired. This report demonstrates that even with appropriate medical decision-making, poor outcomes still result, especially in patients with comorbidities including multivessel disease, respiratory illness, and endocarditis. This study suggests that continuing to characterize repairs or replacements of the mitral valve is essential. Additionally, aggressive and newly emerging procedures, such as percutaneous approaches to mitral valve repair or replacement, may be considered for use to mitigate negative outcomes, especially with an aging population.

Role of matrix metalloproteinases in mitral valve regurgitation: Association between the of MMP-1, MMP-9, TIMP-1, and TIMP-2 expression, degree of mitral valve insufficiency, and pathologic etiology

BACKGROUND

The pathogenesis of mitral valve insufficiency is not yet fully understood. Several studies stressed the role of matrix metalloproteinases (MMPs) in the emergence of valvular pathologies. The primary objective of the present study is to analyze the role of selected MMPs and their inhibitors in mitral valve insufficiency.

PATIENTS AND METHODS

Eighty patients (33 female/47 male, mean age 67 years) underwent cardiopulmonary bypass surgery for mitral valve reconstruction between 2007 and 2015. All patients suffered from mitral insufficiency (MI) Stages iii and iv. When tissue resection was acquired specimens were taken immediately frozen and used for histological examination. Expression of MMP-1, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 was examined immunohistochemically and distribution was analyzed in regard to preoperative clinical, echocardiographic, and histopathological findings.

RESULTS

A clear correlation between the MMP expression and the MI degree of severity could be shown. The expression of MMPs proved to be high in relation to mild insufficiencies and relatively weak in the case of severe ones. Additionally, the etiology of the MI was considered in the analysis and a significant difference in the expression of MMPs between the mitral valves with endocarditis and the ones featuring a degenerative disease could be shown. Within the group of valves with degenerative diseases, no significant difference could be established between the subgroups (myxoid and sclerosed valves).

CONCLUSION

The increased expression of MMPs and their inhibitors in mild insufficiencies could prove that the molecular changes in the valve precede the macroscopical and thus the echocardiographically diagnosable changes. Hence, new options for early diagnosis and therapy of MIs should be examined in further studies, respectively. Herein, the correlation of the MMP blood levels with MMP tissue expression should be addressed for surgical therapeutical decisions.

Progression of Mitral Regurgitation in Rheumatic Valve Disease: Role of Left Atrial Remodeling

Introduction

Mitral regurgitation (MR) is the most common valve abnormality in rheumatic heart disease (RHD) often associated with stenosis. Although the mechanism by which MR develops in RHD is primary, longstanding volume overload with left atrial (LA) remodeling may trigger the development of secondary MR, which can impact on the overall progression of MR. This study is aimed to assess the incidence and predictors of MR progression in patients with RHD.

Methods

Consecutive RHD patients with non-severe MR associated with any degree of mitral stenosis were selected. The primary endpoint was a progression of MR, which was defined as an increase of one grade in MR severity from baseline to the last follow-up echocardiogram. The risk of MR progression was estimated accounting for competing risks.

Results

The study included 539 patients, age of 46.2 ± 12 years and 83% were women. At a mean follow-up time of 4.2 years (interquartile range [IQR]: 1.2–6.9 years), 54 patients (10%) displayed MR progression with an overall incidence of 2.4 per 100 patient-years. Predictors of MR progression by the Cox model were age (adjusted hazard ratio [HR] 1.541, 95% CI 1.222–1.944), and LA volume (HR 1.137, 95% CI 1.054–1.226). By considering competing risk analysis, the direction of the association was similar for the rate (Cox model) and incidence (Fine-Gray model) of MR progression. In the model with LA volume, atrial fibrillation (AF) was no longer a predictor of MR progression. In the subgroup of patients in sinus rhythm, 59 had an onset of AF during follow-up, which was associated with progression of MR (HR 2.682; 95% CI 1.133–6.350).

Conclusions

In RHD patients with a full spectrum of MR severity, progression of MR occurs over time is predicted by age and LA volume. LA enlargement may play a role in the link between primary MR and secondary MR in patients with RHD.

Collagen Fibrillogenesis in the Mitral Valve: It's a Matter of Compliance

Collagen fibers are essential structural components of mitral valve leaflets, their tension apparatus (chordae tendineae), and the associated papillary muscles. Excess or lack of collagen fibers in the extracellular matrix (ECM) in any of these structures can adversely affect mitral valve function. The organization of collagen fibers provides a sophisticated framework that allows for unidirectional blood flow during the precise opening and closing of this vital heart valve. Although numerous ECM molecules are essential for the differentiation, growth, and homeostasis of the mitral valve (e.g., elastic fibers, glycoproteins, and glycans), collagen fibers are key to mitral valve integrity. Besides the inert structural components of the tissues, collagen fibers are dynamic structures that drive outside-to-inside cell signaling, which informs valvular interstitial cells (VICs) present within the tissue environment. Diversity of collagen family members and the closely related collagen-like triple helix-containing proteins found in the mitral valve, will be discussed in addition to how defects in these proteins may lead to valve disease.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Advances in Mitral Valve Repair for Degenerative Mitral Regurgitation: Philosophy, Technical Details, and Long-Term Results

Degenerative mitral valve disease represents the most common cause of mitral regurgitation in industrialized countries. When left untreated, patients with severe degenerative mitral regurgitation show a poor clinical outcome. Conversely, a timely and appropriate correction provides a restored life expectancy and a good quality of life. Therefore, in this scenario, surgical mitral valve repair represents the gold standard of treatment. This review aims to analyze the indications, timing, and contemporary surgical techniques of mitral valve repair for degenerative mitral regurgitation. Moreover, the value of heart team approach and centers of excellence for mitral valve repair are also deeply discussed.

Putative Circulating MicroRNAs Are Able to Identify Patients with Mitral Valve Prolapse and Severe Regurgitation

Mitral valve prolapse (MVP) associated with severe mitral regurgitation is a debilitating disease with no pharmacological therapies available. MicroRNAs (miRNA) represent an emerging class of circulating biomarkers that have never been evaluated in MVP human plasma. Our aim was to identify a possible miRNA signature that is able to discriminate MVP patients from healthy subjects (CTRL) and to shed light on the putative altered molecular pathways in MVP. We evaluated a plasma miRNA profile using Human MicroRNA Card A followed by real-time PCR validations. In addition, to assess the discriminative power of selected miRNAs, we implemented a machine learning analysis. MiRNA profiling and validations revealed that miR-140-3p, 150-5p, 210-3p, 451a, and 487a-3p were significantly upregulated in MVP, while miR-223-3p, 323a-3p, 340-5p, and 361-5p were significantly downregulated in MVP compared to CTRL (p ≤ 0.01). Functional analysis identified several biological processes possible linked to MVP. In addition, machine learning analysis correctly classified MVP patients from CTRL with high accuracy (0.93) and an area under the receiving operator characteristic curve (AUC) of 0.97. To the best of our knowledge, this is the first study performed on human plasma, showing a strong association between miRNAs and MVP. Thus, a circulating molecular signature could be used as a first-line, fast, and cheap screening tool for MVP identification.

Midterm results of transventricular mitral valve repair: Single-center experience

OBJECTIVE

The study objective was to evaluate the midterm outcomes of transventricular mitral valve repair and its association with the initial anatomy of the mitral valve.

METHODS

This nonrandomized observational study included 88 patients (mean age, 60 years; 69% were men) who underwent transventricular mitral valve repair for severe degenerative mitral regurgitation between 2011 and 2017. Mitral valve function was assessed by echocardiography at 1 and 6 months and annually after the procedure. According to the location of mitral valve pathology, all patients were stratified into 4 anatomic types (A, B, C, and D). Results were assessed using Kaplan-Meier method, mixed-effects continuation ratio model, and multivariable Cox regression.

RESULTS

Median follow-up of 42 months (interquartile range, 27-55) was complete for 83 patients (94.3%). There were 3 late deaths: 2 cardiac and 1 noncardiac. Recurrent mitral regurgitation greater than 2+ was observed in 29 patients (33%), and 18 patients (20.5%) underwent repeat surgery. Device success was 82% in type A at 6 months and thereafter; 87%, 85%, and 75% at 6, 12, and 36 months in type B, respectively; and 53% at 1 month and 20% at 24 months in type C. Probability of postoperative mitral regurgitation progression was higher in patients with greater preoperative left ventricular end-diastolic diameter, type B pathology, and type C pathology (P < .05). Risk factors of mitral regurgitation recurrence included increased left ventricle size (hazard ratio, 1.11; 95% confidence interval, 1.04-1.20; P = .001) and type C pathology (hazard ratio, 5.99; 95% confidence interval, 1.87-19.21; P = .003).

CONCLUSIONS

Initial acceptable mitral regurgitation reduction after transventricular mitral valve repair of isolated P2 prolapse was possible but found durable in only 82% at 3 years. Higher risk of mitral regurgitation recurrence occurred with complex degenerative pathology.

Don't go breaking my heart valve: historical review of mitral valve replacement

Management of mitral valve disease in the western world continues to lag behind its aortic counterpart, particularly in the realm of percutaneous valve replacement. It is a more complex anatomical region, with varying disease states and unique pathophysiological and epidemiological characteristics that make it a distinct challenge to treat in modern medicine. Latest research and development, however, have provided new answers to the challenges associated with the mitral valve. In this review, the most common disease states afflicting the mitral valve are outlined, specific challenges associated with treatment are discussed, and both current and cutting-edge replacement devices are described. This review focuses on replacement and prosthetic devices, while acknowledging the role of valve repair. The future of mitral valve replacement remains to be seen, as new methodologies and prosthetic designs continue to present themselves as the best answer to the challenge.

Causes and mechanisms of isolated mitral regurgitation in the community: clinical context and outcome

AIMS

To define the hitherto unknown aetiology/mechanism distributions of mitral regurgitation (MR) in the community and the linked clinical characteristics/outcomes.

METHODS AND RESULTS

We identified all isolated, moderate/severe MR diagnosed in our community (Olmsted County, MN, USA) between 2000 and 2010 and classified MR aetiology/mechanisms. Eligible patients (n = 727) were 73 ± 18 years, 51% females, with ejection fraction (EF) 49 ± 17%. MR was functional (FMR) in 65%, organic (OMR) in 32% and 2% mixed. Functional MR was linked to left ventricular remodelling (FMR-v) 38% and isolated atrial dilatation (FMR-a) 27%. At diagnosis FMR-v vs. FMR-a, vs. OMR displayed profound differences (all P < 0.0001) in age (73 ± 14, 80 ± 10, 68 ± 21years), male-sex (59, 33, 51%), atrial-fibrillation (28, 54, 13%), EF (33 ± 14, 57 ± 11, 61 ± 10%), and regurgitant-volume (38 ± 13, 37 ± 11, 51 ± 24 mL/beat). Dominant MR mechanism was Type I (normal valve-movement) 38%, Type II (excessive valve-movement) 25%, Type IIIa (diastolic movement-restriction) 3%, and Type IIIb (systolic movement-restriction) 34%. Outcomes were mediocre with excess-mortality vs. general-population in FMR-v [risk ratio 3.45 (2.98-3.99), P < 0.0001] but also FMR-a [risk ratio 1.88 (1.52-2.25), P < 0.0001] and OMR [risk ratio 1.83 (1.50-2.22), P < 0.0001]. Heart failure was frequent, particularly in FMR-v (5-year 83 ± 3% vs. 59 ± 4% FMR-a, 40 ± 3% OMR, P < 0.0001). Mitral surgery during patients' lifetime was performed in 4% of FMR-v, 3% of FMR-a, and 37% of OMR.

CONCLUSION

Moderate/severe isolated MR in the community displays considerable aetiology/mechanism heterogeneity. Functional MR dominates, mostly FMR-v but FMR-a is frequent and degenerative MR dominates OMR. Outcomes are mediocre with excess-mortality particularly with FMR-v but FMR-a, despite normal EF incurs notable excess-mortality and frequent heart failure. Pervasive undertreatment warrants clinical trials of therapies tailored to specific MR cause/mechanisms.

The Human Leukocyte Antigen Locus and Rheumatic Heart Disease Susceptibility in South Asians and Europeans

Rheumatic heart disease (RHD), an autoinflammatory heart disease, was recently declared a global health priority by the World Health Organization. Here we report a genome-wide association study (GWAS) of RHD susceptibility in 1,163 South Asians (672 cases; 491 controls) recruited in India and Fiji. We analysed directly obtained and imputed genotypes, and followed-up associated loci in 1,459 Europeans (150 cases; 1,309 controls) from the UK Biobank study. We identify a novel susceptibility signal in the class III region of the human leukocyte antigen (HLA) complex in the South Asian dataset that clearly replicates in the Europeans (rs201026476; combined odds ratio 1.81, 95% confidence intervals 1.51-2.18, P = 3.48×10-10). Importantly, this signal remains despite conditioning on the lead class I and class II variants (P = 0.00033). These findings suggest the class III region is a key determinant of RHD susceptibility offering important new insight into pathogenesis while partly explaining the inconsistency of earlier reports.

The Frequency of Left Atrial Thrombus on Transthoracic Echocardiogram in Patients with Mitral Stenosis

Background

Patients with mitral stenosis (MS) are more prone to develop left atrial (LA) thrombus. This cross-sectional study was conducted to determine the frequency of LA thrombus on transthoracic echocardiography (TTE) in patients with MS.

Methods

In this study, we included patients diagnosed with MS undergoing TTE at the echocardiography department of the National Institute of Cardiovascular Disease (NICVD), Karachi, Pakistan. The severity of MS was classified based on the mitral valve area (MVA) as follows: very severe: MVA of ≤1.0 cm²; severe: MVA of ≤1.5 cm²; and mild to moderate: MVA of >1.5 cm². The LA thrombus was observed and noted on TTE.

Results

A total of 256 MS patients were included in this study, out of which 46.5% (119) were male. The mean age was 33.78 ±11.51 years. MS was classified as mild to moderate in 3.5% of the patients, severe in 54.3%, and very severe in 42.2%. In 98.8% of the patients, the etiology of MS was rheumatic. LA thrombus was observed in 25% (64) of the patients and LA smoke was observed in 12.1% (31). Among other findings, mitral regurgitation (MR) was observed in 17.2% of the patients, aortic regurgitation (AR) in 5.1%, aortic stenosis (AS) in 4.7%, and tricuspid regurgitation (TR) in 48.8%. Five (2%) patients had atrial septal defect (ASD), 17.3% had left ventricular (LV) dysfunction, 15.2% had right ventricular (RV) dysfunction, and vegetation was seen in 11.8% of the patients. Patients with LA thrombus were found to be associated with the following conditions on a higher scale compared to those without: decreased ejection fraction (EF) (52 ±8.5% vs. 54.94 ±6.6%; p: 0.011); RV dysfunction (39.1% vs. 7.3%; p: <0.001); and presence of associated pathologies (82.8% vs. 43.8%; p: <0.001).

Conclusion

LA thrombus on TTE was detected in a significant number (25%) of patients with MS. It was also found to be strongly associated with the severity of the disease, reduced EF, RV dysfunction, and the presence of associated value pathologies.

Rheumatic Mitral Stenosis: Long-Term Follow-Up of Adult Patients with Nonsevere Initial Disease

INTRODUCTION

There is no consensus regarding the natural history of rheumatic mitral stenosis (MS) among adults presenting with nonsevere disease. This study aims to describe the progression of stenosis among adult rheumatic MS patients, to identify predictive factors for progression, and to assess the incidence of complications.

METHODS

A retrospective cohort analysis was performed among patients with rheumatic MS treated at a single center. Eighty-five patients were included with mild to moderate MS, ≥30 years old on initial echocardiography. Demographics, medical history, echocardiographic reports over at least 10 years, and related complications were obtained from a computerized database.

RESULTS

Over a period of 13.1 ± 2.38 years, 75 patients (88%) had no significant progression in stenosis severity. The final echocardiographic assessment demonstrated 2 groups with a significant difference between them regarding the mitral valve area (1.58 ± 0.44 vs. 1.1 ± 0.26 cm2, p = 0.001) and mean valvular pressure gradient (6.27 ± 2.52 vs. 8.5 ± 2.69 mm Hg, p = 0.01). Patients with indolent MS (group A) were compared to patients with progressive disease (group B), and a higher percent of Bedouin patients were found in group B (OR 8.036, p = 0.015). No significant differences were found in other parameters. Complications including atrial fibrillation, cerebral ischemic events, and impaired right ventricle function, although frequent, were not statistically different between the groups.

CONCLUSIONS

An indolent natural progression of rheumatic MS was observed in our study. Despite this finding, it still has potentially deleterious effects. Bedouin patients have a higher risk for progressive disease.

Quantitative Description of Mitral Valve Geometry Using Real-Time Three-Dimensional Echocardiography

Objectives

Leaflet and annular geometry are important determinants of mitral valve (MV) stress. Repair techniques which optimize valvular geometry will reduce stress and potentially increase repair durability. The development of such procedures will require image processing methodologies that provide a quantitative description of three-dimensional valvular geometry. Using three-dimensional echocardiography in conjunction with novel geometric modeling and rendering techniques, we have developed a high-resolution, quantitative, three-dimensional methodology for imaging the human MV.

Methods

Five normal adults underwent MV imaging using real-time three-dimensional echocardiography. Using specially designed image analysis software, multiple valvular geometric parameters, including the magnitude and orientation of leaflet curvature, leaflet surface area, annular height, intercommissural width, septolateral annular diameter, and annular area were determined for each subject. Image rendering techniques that allow for the clear and concise presentation of this detailed information are also presented.

Results

Although three-dimensional annular and leaflet geometry were found to be highly conserved among normal human subjects, substantial regional variation in leaflet geometry was observed. Interestingly, leaflet geometric heterogeneity was most pronounced in the midposterior leaflet, the region most commonly involved in leaflet flail in subjects with myxomatous disease.

Conclusions

The image processing and graphical rendering techniques that we have developed can be used to provide a complete description of three-dimensional MV geometry in human subjects. Widespread application of these techniques to normal subjects and patients with MV disease will provide insight into the geometric basis of both valvular pathology and repair durability.

Papillary muscle ventricular arrhythmias in patients with arrhythmic mitral valve prolapse: Electrophysiologic substrate and catheter ablation outcomes

BACKGROUND

Mitral valve prolapse (MVP) is a common valve condition and has been associated with sudden cardiac death. Premature ventricular contractions (PVCs) from the papillary muscles (PMs) may play a role as triggers for ventricular fibrillation (VF) in these patients.

OBJECTIVES

To characterize the electrophysiological substrate and outcomes of catheter ablation in patients with MVP and PM PVCs.

METHODS

Of 597 patients undergoing ablation of ventricular arrhythmias during the period 2012-2015, we identified 25 patients with MVP and PVCs mapped to the PMs (64% female). PVC-triggered VF was the presentation in 4 patients and a fifth patient died suddenly during follow-up. The left ventricle ejection fraction (LVEF) was 50.5% ± 11.8% and PVC burden was 24.4% ± 13.1%. A cardiac magnetic resonance imaging was performed in nine cases and areas of late gadolinium enhancement were found in four of them. A detailed LV voltage map was performed in 11 patients, three of which exhibited bipolar voltage abnormalities. Complete PVC elimination was achieved in 19 (76%) patients and a significant reduction in PVC burden was observed in two (8%). In patients in which the ablation was successful, the PVC burden decreased from 20.4% ± 10.8% to 6.3% ± 9.5% (P = 0.001). In 5/6 patients with depressed LVEF and successful ablation, the LV function improved postablation. No significant differences were identified between patients with and without VF.

CONCLUSIONS

PM PVCs are a source of VF in patients with MVP and can induce PVC-mediated cardiomyopathy that reverses after PVC suppression. Catheter ablation is highly successful with more than 80% PVC elimination or burden reduction.

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.

[Percutaneous treatment of mitral regurgitation by Mitraclip in the elderly]

Mitral regurgitation (MR) is the second most common form of valvular heart disease. It is classified as either primary (degenerative) or secondary (functional). Secondary MR is the consequence of myocardium disease. Primary MR from degenerative valve disease is due to a primary disruption of the mitral valve apparatus from either prolapsed or flail leaflets. It covers all aetiologies in which intrinsic lesions affect one or several components of the mitral valve apparatus. Gold-standard therapeutic management of severe primary MR is surgery usually to repair but sometime to replace the mitral valve. However patients considered to be at high-risk due to their age or the presence of comorbidities - accounting for 50% of all patients - are not eligible for surgery. Catheter-based interventions have been developed to correct MR percutaneously. The only such intervention which has been evaluated in organic MR is the edge-to-edge procedure using the MitraClip^® (Abbott Vascular, Menlo Park, CA). MitraClip^® offers an alternative to open surgical repair or replacement via a minimally invasive route and it was shown in the EVEREST II study that MitraClip^® was safer than surgery even though it was less effective in reducing MR. A substantial number of patients are ineligible for mitral valve surgery because of prohibitive surgical risk. For those patients, MitraClip^® may offer an alternative treatment option. Percutaneous edge-to-edge repair is the first percutaneous option accepted in the 2012 ESC guidelines: Percutaneous edge-to-edge procedure may be considered in patients with symptomatic severe primary MR who fulfill the echo criteria of eligibility, are judged inoperable or at high surgical risk by a 'heart team', and have a life expectancy greater than 1 year (recommendation class IIb, level of evidence C). Because of its frailty, MitraClip^® in the elderly may be a good alternative to mitral surgery when indicated for primary or secondary MD.

Transcatheter mitral valve chord repair

The field of mitral valve disease diagnosis and management is rapidly evolving. New understanding of pathophysiology and improvements in the adoption of sophisticated multimodality imaging modalities have led to early diagnosis and to more complex treatment. The most common cause of mitral regurgitation (MR) in the western world is in the primary alteration of the valve, which leads to degenerative leaflet prolapse due to chordal elongation or rupture and annular dilatation. Untreated, significant MR has a negative impact prognosis, leading to reduction of survival. In the setting of degenerative MR, surgical repair currently represents the standard of care. Treatment of asymptomatic patients with severe MR in the Valve Center of Excellence, in which successful repair reaches more than 95% and surgical mortality less than 1%, symbolizes the direction for the next years. Transcatheter mitral valve repair with different devices, more recently the chordal replacement ones, is providing good outcomes and became a therapeutic option in high-risk patients with degenerative MR. In the future, more advances are expected from further development of interventional techniques, careful evaluation and better patient selection. This review will focus on long-term surgical outcomes of mitral valve repair with artificial chordae and on the emerging transcatheter chordal repair devices as therapeutic options for degenerative MR patients.

The Accuracy of a Large V Wave in the Pulmonary Capillary Wedge Pressure Waveform for Diagnosing Current Mitral Regurgitation

Background: Large V waves in the pulmonary capillary wedge pressure (PCWP) waveform traditionally indicate severe mitral regurgitation (MR). However, our understanding of MR etiology and hemodynamics has changed in recent decades. Objectives: We aimed to reevaluate the association between large V waves and current MR to determine whether traditional large V wave criteria remain optimal. Method: We reviewed 1,964 right heart catheterizations (RHCs) performed at our institution from 2010 to 2017, and retrospectively selected 126 patients with sinus rhythm who underwent echocardiography within 2 days (0.3 ± 0.5 days) of the RHC. The diagnostic accuracy of 3 traditional criteria for large V waves was assessed, and the optimal cut-off points were determined as those with the maximal Youden indices. Results: Severe MR was observed on echocardiography in 26 (21%) patients, including 15 (58%) with Carpentier classification type II MR and 11 (42%) with type IIIB MR. Large V waves, defined as a difference between the peak V wave and mean PCWP ≥10 mm Hg, had a high specificity of 94% (95% confidence interval: 87–98%), but a low sensitivity of 27% (12–48%) for diagnosing severe MR. The optimal cut-off point for the V wave was 3 mm Hg above the mean PCWP, with a sensitivity of 73% (52–88%) and a specificity of 64% (54–73%). Conclusions: For diagnosing current MR, the cut-off point for a large V wave should be reduced from that previously employed for rheumatic valvular heart disease. This information may be useful in guiding contemporary transcatheter therapies for MR under RHC monitoring.

Mitral leaflet separation index. An easy two dimensional echocardiography technique for assessment of mitral valve area before and after percutaneous balloon mitral valvuloplasty

AIM

To evaluate the reliability of the mitral leaflet separation (MLS) index against the traditional echocardiographic methods in measuring mitral valve area (MVA) pre and post percutaneous balloon mitral valvuloplasty (PBMV).

METHODS

Ninety patients suffering symptomatic moderate to severe MS underwent PBMV at Ain Shams University Hospital in cardiology department. Seventy of the patients were females representing 77.8% and 20 were males representing 22.2%. Their age ranged from 22 to 56 years. All patients were subjected to full transthoracic echocardiography (TTE) examination pre and post PBMV. MLS index was introduced as a comparative parameter with traditional echocardiographic methods for assessment of MVA, measuring average of distance between tips of MV leaflets in parasternal long axis and four chamber two dimensional echocardiographic views.

RESULTS

MVA increased from 0.95 ± 0.28 to 2.21 ± 0.41 cm2 (P=0.001) using 2D planimetry; and increased from 0.93 ± 0.23 to 2.21 ± 0.46 cm2 (P= 0.0011) by pressure half time method (PHT). MLS index was correlated with MVA by 2D planimetry pre and post PBMV (r=0.453) and (r=0.668) respectively (p=0.0001) and strongly correlated with MVA using PHT post PBMV (r=0.768) (p=0.0001). Post PBMV 14 patients suffered significant mitral regurgitation 3 of them were transferred to surgery. MLS index above 11.75 mm and below 9.15 mm had excellent positive predictive value for detecting mild and severe MS respectively.

CONCLUSION

The MLS index it is a simple and effective method for assessment of the MVA, it has an excellent correlation with MVA with an excellent sensitivity and specificity for the prediction of effective MVA. The MLS index cannot evaluate outcome of PBMV because it is an anatomical parameter and not flow dependent thus does not correlate with grades of mitral regurgitation.

Mechanistic insights of the left ventricle structure and fibrosis in the arrhythmogenic mitral valve prolapse

Mitral valve prolapse (MVP) is a common and benign condition. However, some anatomic forms have been recently associated with life-threatening ventricular arrhythmias and sudden cardiac death. Imaging MVP holds the promise of individualized MVP risk assessment. Noninvasive imaging techniques available today are playing an increasingly important role in the diagnosis, prognosis and monitoring of MVP. In this article, we will review the current evidence on arrhythmogenic MVP, with special focus on the utility of echocardiography and CMR for identifying benign and "malignant" forms of MVP. The clinical relevance of this manuscript lies in the value of imaging technology to improve MVP risk prediction, including those arrhythmic-MVP cases with a higher risk of sudden cardiac death.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.

The impact of functional vs degenerative mitral regurgitation on clinical outcomes among patients undergoing transcatheter aortic valve implantation

BACKGROUND

Among patients undergoing transcatheter aortic valve implantation (TAVI), concomitant mitral regurgitation (MR) has been associated with adverse prognosis. We aimed to assess long-term clinical outcomes according to MR etiology.

METHODS

In a single-center registry of consecutive patients undergoing TAVI, we investigated the impact of functional (FMR) vs degenerative (DMR) MR on cardiovascular (CV) mortality throughout 2years of follow-up.

RESULTS

Among 603 patients (mean age 82.4±5.7years, 55% female) undergoing TAVI, 149 patients had moderate or severe MR (24.7%). Functional MR and DMR were documented in 53 (36%) and 96 (64%) patients, respectively. At 2years, patients with FMR and DMR had higher rates of CV mortality (30.2% vs 32.4%) as compared with patients with no MR (14.6%; FMR vs no MR: hazard ratio [HR] 2.32, 95% CI 1.34-4.02, P=.003; DMR vs no MR: HR 2.56, 95% CI 1.66-3.96, P<.001). In adjusted analyses, DMR was associated with an increased risk of CV mortality throughout the 2-year follow-up (adjusted HR 2.21, 95% CI 1.4-3.49, P=.001) as compared with FMR (adjusted HR 1.13, 95% CI 0.59-2.18, P=.707). Relevant MR was postprocedurally significantly reduced in both the DMR and FMR groups, whereas improvement of a decreased left ventricular ejection fraction was predominantly seen in the FMR group as compared with baseline.

CONCLUSION

Patients with severe, symptomatic aortic stenosis undergoing TAVI complicated by moderate or severe MR portend impaired prognosis. Particularly, patients with DMR are at increased risk for CV mortality during long-term follow-up.

Surgery for rheumatic mitral valve disease in sub-saharan African countries: why valve repair is still the best surgical option

Rheumatic valve disease, a consequence of acute rheumatic fever, remains endemic in developing countries in the sub-Saharan region where it is the leading cause of heart failure and cardiovascular death, involving predominantly a young population. The involvement of the mitral valve is pathognomonic and mitral surgery has become the lone therapeutic option for the majority of these patients. However, controversies exist on the choice between valve repair or prosthetic valve replacement. Although the advantages of mitral valve repair over prosthetic valve replacement in degenerative mitral disease are well established, this has not been the case for rheumatic lesions, where the use of prosthetic valves, specifically mechanical devices, even in poorly compliant populations remains very common. These patients deserve more accurate evaluation in the choice of the surgical strategy which strongly impacts the post-operative outcomes. This report discusses the factors supporting mitral repair surgery in rheumatic disease, according to the patients' characteristics and the effectiveness of the current repair techniques compared to prosthetic valve replacement in developing countries.

B-type Natriuretic Peptide as an Index of Symptoms and Severity of Chronic Rheumatic Mitral Regurgitation

Background:

The most common causes of severe mitral regurgitation (MR) in developing countries are rheumatic heart disease. The plasma level of B-type natriuretic peptide (BNP) is known to increase with left ventricular (LV) dysfunction.

Aim of the Work:

To study BNP level as an index of symptoms and severity of chronic rheumatic MR.

Patients and Methods:

One hundred and forty patients with rheumatic MR and LV ejection fractions (EFs) of >55% underwent assessment of symptoms, transthoracic echocardiography, and measurement of BNP. Results: The level of BNP rose with increasing left atrium (LA) dimensions and volumes, LV dimensions and volumes, echocardiographic parameters of MR severity (width of the vena contracta, regurgitation jet area, effective regurgitation orifice area, and regurgitant volume), and E waves.

Results:

BNP was significantly higher in patients with severe MR compared with moderate and mild MR (P < 0.001), and using cutoff point of 61 pg/mL mm had 97% sensitivity and 89% specificity for predicting patients with severe MR (0.99, 95% confidence interval [CI] 0.9–1). BNP was significantly higher in patients with New York Heart Association (NYHA III) compared with NYHA II, I and asymptomatic patients (P < 0.001) and using cutoff point of 53 pg/mL had 97% sensitivity and 87% specificity for predicting symptomatic patients with symptomatic MR (0.81, 95% CI 0.70–0.92).

Conclusions:

BNP level increase with increasing severity of rheumatic MR and are higher in symptomatic compared to asymptomatic patients, even in the presence of normal EF%.

Mitral annulus morphologic and functional analysis using real time tridimensional echocardiography in patients submitted to unsupported mitral valve repair

Introduction

Mitral valve repair is the treatment of choice to correct mitral insufficiency, although the literature related to mitral valve annulus behavior after mitral repair without use of prosthetic rings is scarce.

Objective

To analyze mitral annulus morphology and function using real time tridimensional echocardiography in individuals submitted to mitral valve repair with Double Teflon technique.

Methods

Fourteen patients with mitral valve insufficiency secondary to mixomatous degeneration that were submitted to mitral valve repair with the Double Teflon technique were included. Thirteen patients were in FC III/IV. Patients were evaluated in preoperative period, immediate postoperative period, 6 months and 1 year after mitral repair. Statistical analysis was made by repeated measures ANOVA test and was considered statistically significant P<0.05.

Results

There were no deaths, reoperation due to valve dysfunction, thromboembolism or endocarditis during the study. Posterior mitral annulus demonstrated a significant reduction in immediate postoperative period (P<0.001), remaining stable during the study, and presents a mean of reduction of 25.8% comparing with preoperative period. There was a significant reduction in anteroposterior and mediolateral diameters in the immediate postoperative period (P<0.001), although there was a significant increase in mediolateral diameter between immediate postoperative period and 1 year. There was no difference in mitral internal area variation over the cardiac cycle during the study.

Conclusion

Segmentar annuloplasty reduced the posterior component of mitral annulus, which remained stable in a 1-year-period. The variation in mitral annulus area during cardiac cycle remained stable during the study.

Mitral valve disease--current management and future challenges

The field of mitral valve disease diagnosis and management is rapidly changing. New understanding of disease pathology and progression, with improvements in and increased use of sophisticated imaging modalities, have led to early diagnosis and complex treatment. In primary mitral regurgitation, surgical repair is the standard of care. Treatment of asymptomatic patients with severe mitral regurgitation in valve reference centres, in which successful repair is more than 95% and surgical mortality is less than 1%, should be the expectation for the next 5 years. Transcatheter mitral valve repair with a MitraClip device is also producing good outcomes in patients with primary mitral regurgitation who are at high surgical risk. Findings from clinical trials of MitraClip versus surgery in patients of intermediate surgical risk are expected to be initiated in the next few years. In patients with secondary mitral regurgitation, mainly a disease of the left ventricle, the vision for the next 5 years is not nearly as clear. Outcomes from ongoing clinical trials will greatly inform this field. Use of transcatheter techniques, both repair and replacement, is expected to substantially expand. Mitral annular calcification is an increasing problem in elderly people, causing both mitral stenosis and regurgitation which are difficult to treat. There is anecdotal experience with use of transcatheter valves by either a catheter-based approach or as a hybrid technique with open surgery, which is being studied in early feasibility trials.

Mitral valve replacement for mitral stenosis: A 15-year single center experience

Objectives

Mitral valve replacement with either a bioprosthetic or a mechanical valve is the treatment of choice for severe mitral stenosis. However, choosing a valve implant type is still a subject of debate. This study aimed to evaluate and compare the early and late outcomes of mitral valve replacement [mechanical (MMV) vs. bioprosthetic (BMV)] for severe mitral stenosis.

Methods

A retrospective cohort study was performed on data involving mitral stenosis patients who have undergone mitral valve replacement with either BMV (n = 50) or MMV (n = 145) valves from 1999 to 2012. Data were collected from the patients’ records and follow-up through telephone calls. Data were analyzed for early and late mortality, New York Heart Association (NYHA) functional classes, stroke, pre- and postoperative echocardiographic findings, early and late valve-related complications, and survival. Chi-square test, logistic regression, Kaplan–Meier curve, and dependent proportions tests were some of the tests employed in the analysis.

Results

A total of 195 patients were included in the study with a 30-day follow-up echocardiogram available for 190 patients (97.5%), while 103 (53%) were available for follow-up over the telephone. One patient died early postoperatively; twelve patients died late in the postoperative period, six in the bioprosthesis group and six in the mechanical group. The late mortality had a significant association with postoperative stroke (p < 0.001) and postoperative NYHA Classes III and IV (p = 0.002). Postoperative NYHA class was significantly associated with age (p = 0.003), pulmonary disease (p = 0.02), mitral valve implant type (p = 0.01), and postoperative stroke (p = 0.02); 14 patients had strokes in the mechanical (9) and in the bioprosthetic (5) groups. NYHA classes were significantly better after the replacement surgeries (p < 0.001). BMV were significantly associated with worse survival (p = 0.03), worse NYHA postoperatively (p = 0.01), and more reoperations (p = 0.006). Survival was significantly better with MMV (p = 0.03). When the two groups were matched for age and mitral regurgitation, the analysis revealed that BMV were significantly associated with reoperations (p = 0.02) but not significantly associated with worse survival (p = 0.4) or worse NYHA (p = 0.4).

Conclusion

MMV replacement in mitral stenosis patients is associated with a lower reoperation rate, but there was no difference in survival compared with BMV replacement.

Long-term outcomes of mitral valve repair versus replacement for degenerative disease: a systematic review

The short-term advantage of mitral valve repair versus replacement for degenerative disease has been extensively documented. These advantages include lower operative mortality, improved survival, better preservation of left-ventricular function, shorter post-operative hospital stay, lower total costs, and fewer valve-related complications, including thromboembolism, anticoagulation-related bleeding events and late prosthetic dysfunction. More recent written data are available indicating the long-term advantage of repair versus replacement. While at some institutions, the repair rate for degenerative disease may exceed 90%, the national average in 2007 was only 69%. Making direct comparisons between mitral valve repair and replacement using the available studies does present some challenges however, as there are often differences in baseline characteristics between patient groups as well as other dissimilarities between studies. The purpose of this review is to systematically summarize the long-term survival and reoperation data of mitral valve repair versus replacement for degenerative disease. A PubMed search was done and resulted in 12 studies that met our study criteria for comparing mitral valve repair versus replacement for degenerative disease. A systematic review was then conducted abstracting survival and reoperation data.

At the Heart of the Matter

Echocardiography is an excellent method for evaluating cardiac morphology and dynamic function. It has a long history of innovative thinking mixed with some degree of serendipity. Its early applications were as a tool to evaluate the mitral valve, left ventricular characteristics, and pericardial effusion. Today it has evolved into a robust modality that allows for a very wide range cardiac interrogation, able to evaluate the valves, chambers, myocardium, and pericardium. The practice of echocardiography also is often separate from that of general or vascular sonography. The objective of this article is to provide the non–cardiac sonographer with an overview and appreciation of the basic principles and practices of echocardiography. It is not meant as a guide to scanning but rather, as a vehicle to spark the interest and imagination of the reader.

Mitral valve disease

In industrially developed countries, moderate or severe mitral valve disease is relatively common and is usually caused by prolapse or is secondary to left ventricular disease. Mitral stenosis (MS), however, is uncommon and usually a sequela of rheumatic fever. This article discusses the natural history of mitral regurgitation and MS and their medical and surgical management.

A meta-analysis of MitraClip system versus surgery for treatment of severe mitral regurgitation

BACKGROUND

Mitral regurgitation (MR) is the second most common valvular heart disease after aortic stenosis. Without intervention, prognosis is poor in patients with severe symptomatic MR. While surgical repair is recommended for many patients with severe degenerative MR (DMR), as many as 49% of patients do not qualify as they are at high surgical risk. Furthermore, surgical correction for functional MR (FMR) is controversial with suboptimal outcomes and significant perioperative mortality. The percutaneous MitraClip implantation can be seen as a viable option in high surgical risk patients. The purpose of this meta-analysis is to compare the safety, clinical efficacy, and survival outcomes of MitraClip implantation with surgical correction of severe MR.

METHODS

Six electronic databases were searched for original published studies from January 2000 to August 2013. Two reviewers independently appraised studies, using a standard form, and extracted data on methodology, quality criteria, and outcome measures. All data were extracted and tabulated from the relevant articles' texts, tables, and figures and checked by another reviewer.

RESULTS

Overall 435 publications were identified. After applying selection criteria and removing serial publications with accumulating number of patients or increased length of follow-up, four publications with the most complete dataset were included for quality appraisal and data extraction. There was one randomized controlled trial (RCT) and three prospective observational studies. At baseline, patients in the MitraClip group were significantly older (P=0.01), had significantly lower LVEF (P=0.03) and significantly higher EuroSCORE (P<0.0001). The number of patients with post-procedure residual MR severity >2 was significantly higher in the MitraClip group compared to the surgical group (17.2% vs. 0.4%; P<0.0001). 30-day mortality was not statistically significant (1.7% vs. 3.5%; P=0.54), nor were neurological events (0.85% vs. 1.74%; P=0.43), reoperations for failed MV procedures (2% vs. 1%; P=0.56), NYHA Class III/IV (5.7% vs. 11.3; P=0.42) and mortality at 12 months (7.4% vs. 7.3%; P=0.66).

CONCLUSIONS

Despite a higher risk profile in the MitraClip patients compared to surgical intervention, the clinical outcomes were similar although surgery was more effective in reducing MR in the early post procedure period. We conclude the non-inferiority of the MitraClip as a treatment option for severe, symptomatic MR in comparison to conventional valvular surgery.