[Catheter-based and surgical treatment of mitral valve diseases]

There is a broad spectrum of mitral valve diseases ranging from young patients with rheumatic mitral valve stenosis up to older patients with secondary mitral valve regurgitation and numerous comorbidities. A profound understanding of the etiology, anatomical characteristics of mitral valve diseases and current treatment options is necessary to be able to prepare a patient-centered treatment approach. The interdisciplinary collaboration of referring physicians, interventional cardiologists, cardiac surgeons, heart failure and imaging specialists as well as anesthesiologists is a cornerstone of optimal patient treatment.

Insights into malignant mitral valve degenerative disease from a sudden cardiac death cohort highlighting significant measurement differences from normal

AIMS

Mitral valve prolapse (MVP) is an accepted cause of sudden cardiac death (SCD) in most autopsy series. Diagnosis at autopsy relies upon subjective assessment with no established objective pathological criteria. This study set out to establish objective measurements to help pathologists dealing with SCD.

METHODS

We diagnosed 120 (1.5%) cases of MVP in 8108 cases of SCD. We measured the mitral annulus, anterior and posterior leaflets, rough zone and mitral annular disjunction (MAD) in 27 MVP cases and compared them to 54 age- and sex-matched normal mitral valves.

RESULTS

Age of death was 39 ± 16 years, with 59 females and 61 males. History of mild MV disease was present in 19 (16%). Eleven (9%) died associated with exertion. Left ventricular hypertrophy was present in nine (15%) females and 10 (16%) males. Both MV leaflets showed thickening and ballooning in all individuals. MVP showed highly significantly increased annular circumference, elongation and thickening of both leaflets as well as increased MAD (all P < 0.001). Left ventricular fibrosis was present in 108 (90%), with interstitial fibrosis in the posterolateral wall and papillary muscle in 88 (81%) and coexisting replacement fibrosis in 40 (37%).

CONCLUSION

This is the largest MVP associated with SCD series highlighting a young cohort with equal representation of males and females. There is involvement of both leaflets with significant annular dilatation, elongation and thickening of both leaflets with MAD. Left ventricular fibrosis explains arrhythmia. Our quantitative measurements should serve as a reference for pathologists assessing post-mortem hearts for MVP.

SAMHD1 compound heterozygous rare variants associated with moyamoya and mitral valve disease in the absence of other features of Aicardi-Goutières syndrome

Aicardi-Goutières syndrome (AGS) is an autosomal recessive inflammatory syndrome that manifests as an early-onset encephalopathy with both neurologic and extraneurologic clinical findings. AGS has been associated with pathogenic variants in nine genes: TREX1, RNASEH2B, RNASEH2C, RNASEH2A, SAMHD1, ADAR, IFIH1, LSM11, and RNU7-1. Diagnosis is established by clinical findings (encephalopathy and acquired microcephaly, intellectual and physical impairments, dystonia, hepatosplenomegaly, sterile pyrexia, and/or chilblains), characteristic abnormalities on cranial CT (calcification of the basal ganglia and white matter) and MRI (leukodystrophic changes), or the identification of pathogenic/likely pathogenic variants in the known genes. One of the genes associated with AGS, SAMHD1, has also been associated with a spectrum of cerebrovascular diseases, including moyamoya disease (MMD). In this report, we describe a 31-year-old male referred to genetics for MMD since childhood who lacked the hallmark features of AGS patients but was found to have compound heterozygous SAMHD1 variants. He later developed mitral valve insufficiency due to recurrent chordal rupture and ultimately underwent a heart transplant at 37 years of age. Thus, these data suggest that SAMHD1 pathogenic variants can cause MMD without typical AGS symptoms and support that SAMHD1 should be assessed in MMD patients even in the absence of AGS features.

Perioperative and Anesthetic Considerations in Shone's Complex

Shone's complex is a congenital cardiac disease consisting of the following four lesions: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and aortic coarctation. Though not all components are required for a diagnosis, the end result is both left ventricular inflow and outflow obstruction, which typically present in patients as congestive heart failure. The complex pathology requires careful management and surgical decision-making to ensure an optimal outcome. This review will focus on the anatomy, physiology, and perioperative anesthetic management of patients with Shone's complex.

A cardiac intimal sarcoma mimicking infective endocarditis

Primary malignant cardiac tumors are rare and usually misdiagnosed because they can mimic more common intracardiac lesions, therefore, in clinical practice it is important to always consider even uncommon diseases in order to avoid delayed diagnosis and to plan the most appropriate therapeutic strategy in a timely fashion. We report a case of a 73-year-old man with clinical signs and imaging findings (echocardiography) suggesting infective bacterial endocarditis of the mitral valve. However, intraoperative evaluation raised suspicion that the mitral lesions had a different nature. Surgical removal of the mass was performed, and the final correct diagnosis was made through pathologic examination, revealing a mitral valve sarcoma thus allowing for the beginning of specific oncological treatment.

Mitral valve surgery assisted by virtual and augmented reality: Cardiac surgery at the front of innovation

BACKGROUND

Given the variety in mitral valve (MV) pathology and associated surgical techniques, extended reality (XR) holds great potential to assist MV surgeons. This review aims to systematically evaluate the currently available evidence investigating the use of XR and associated technologies in MV surgery.

METHODS

A systematic database search was conducted of original articles and case reports that explored the use of XR and MV surgery in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to February 2022.

RESULTS

Our search yielded 171 articles, of which 15 studies were included in this review, featuring 328 patients. Two main areas of application were identified: (i) pre-operative planning and (ii) predicting post-operative outcomes. The articles reporting outcomes relating to pre-operative planning were further categorised as exploring themes relevant to (i) mitral annular assessment; (ii) training; (iii) evaluation of surgical technique; (iv) surgical approach or plan and (v) selecting ring size or type. Preoperatively, XR has been shown to evaluate mitral annular pathology more accurately than echocardiography, informing the surgeon about the optimal surgical technique, approach and plan for a particular patient's MV pathology. Furthermore, XR could simulate and aid ring size/type selection for MV annuloplasty, creating a personalized surgical plan. Additionally, XR could estimate the postoperative MV biomechanical and physiological characteristics, predicting and pre-empting post-operative complications.

CONCLUSION

XR demonstrated promising applications for assisting MV surgery, enhancing outcomes and patient-centred care, nevertheless, there remain the need for randomized studies to ascertain its feasibility, safety, and validity in clinical practice.

Papillary fibroelastoma originating from the atrial septum touching the mitral valve leading to infective endocarditis: a case report

BACKGROUND

Cardiac papillary fibroelastoma is a rare benign tumor, which is often mistaken for a vegetation. Predominantly asymptomatic, it can cause life-threatening complications. Although rare, mobile papillary fibroelastoma movement between affected valves may hamper valve closure and damage the valve, leading to valvular regurgitation. Endothelial damage increases the risk of developing infective endocarditis. We report a rare case of a highly mobile papillary fibroelastoma originating from the atrial septum touching the mitral valve, leading to mitral regurgitation and, eventually, infective endocarditis.

CASE PRESENTATION

A 26-year-old woman with suspected infective endocarditis was referred to us from a previous hospital after having experienced intermittent fever for a month. Before the fever, she had been experiencing exertional dyspnea. In addition, she had undergone a cesarean section two weeks before this admission. A transthoracic echocardiogram showed a mobile mass originating from the atrial septum touching the mitral valve with severe mitral regurgitation. Computed tomography revealed an occluded right profunda femoris artery with an embolus. Infective endocarditis associated with a mobile vegetation with high embolic risk was diagnosed, and urgent surgery was performed. Following the surgery, examinations revealed papillary fibroelastoma originating from the atrial septum and infective endocarditis of the mitral valve. The histopathological examination confirmed that a mass initially thought to be a mobile vegetation was a papillary fibroelastoma. The postoperative course was uneventful except for pericarditis. There has been no recurrence of infective endocarditis or papillary fibroelastoma.

CONCLUSIONS

The highly mobile papillary fibroelastoma was thought to have caused both chronic mitral regurgitation and infective endocarditis. Mobile papillary fibroelastomas can cause endothelial damage to nearby valves and predispose patients to infective endocarditis.

Dynamic changes in mitral valve extracellular matrix, tissue mechanics and function in a mouse model of Marfan syndrome

OBJECTIVE

Mouse models of Marfan syndrome (MFS) with Fibrillin 1 (Fbn1) variant C1041G exhibit cardiovascular abnormalities, including myxomatous valve disease (MVD) and aortic aneurism, with structural extracellular matrix (ECM) dysregulation. In this study, we examine the structure-function-mechanics relations of the mitral valve related to specific transitions in ECM composition and organization in progressive MVD in MFS mice from Postnatal day (P)7 to 1 year-of-age.

APPROACH AND RESULTS

Mechanistic links between mechanical forces and biological changes in MVD progression were examined in Fbn1C1041G/+ MFS mice. By echocardiography, mitral valve dysfunction is prevalent at 2 months with a decrease in cardiac function at 6 months, followed by a preserved cardiac function at 12 months. Mitral valve (MV) regurgitation occurs in a subset of mice at 2-6 months, while progressive dilatation of the aorta occurs from 2 to 12 months. Mitral valve tissue mechanical assessments using a uniaxial Permeabilizable Fiber System demonstrate decreased stiffness of MFS MVs at all stages. Histological and microscopic analysis of ECM content, structure, and fiber orientation demonstrate that alterations in ECM mechanics, composition, and organization precede functional abnormalities in Fbn1C1041G/+MFS MVs. At 2 months, ECM abnormalities are detected with an increase in proteoglycans and decreased stiffness of the mitral valve. By 6-12 months, collagen fiber remodeling is increased with abnormal fiber organization in MFS mitral valve leaflets. At the same time, matrifibrocyte gene expression characteristic of collagen-rich connective tissue is increased, as detected by RNA in situ hybridization and qPCR. Together, these studies demonstrate early prevalence of proteoglycans at 2 months followed by upregulation of collagen structure and organization with age in MVs of MFS mice.

CONCLUSIONS

Altogether, our data indicate dynamic regulation of mitral valve structure, tissue mechanics, and function that reflect changes in ECM composition, organization, and gene expression in progressive MVD. Notably, increased collagen fiber organization and orientation, potentially dependent on increased matrifibrocyte cell activity, is apparent with altered mitral valve mechanics and function in aging MFS mice.

Nonbacterial Thrombotic Endocarditis Caused by Early-stage Lung Cancer: An Autopsy Case Report

Nonbacterial thrombotic endocarditis (NBTE) is a manifestation of prothrombotic status observed in patients with malignancy. Most cases are discovered only in the advanced stages. However, cancer in early stages may also induce NBTE development. We herein report an 87-year-old man with NBTE with multiple thromboembolization coexisting with lung cancer in early clinical stage. Autopsy findings revealed platelet- and fibrin-rich vegetations in both the tricuspid and mitral valves without evidence of bacterial infection. NBTE should be considered in cases with occult thromboembolization. Not only the presence of typical vegetation but irregular leaflet thickening should be monitored with careful echocardiographic examinations.

Dysfunctioning mechanical mitral valve prosthesis: When thrombus over pannus makes hinders diagnosis

Prosthetic valve obstruction is a rare but potentially lethal complication. The most frequent causes are thrombus and pannus formation, in the absence of infectious data. Diagnosis is not always easy using cardiac CT scanning and in 46%-85% of cases thrombus and pannus coexist, complicating the diagnosis. A rapid diagnosis is essential to avoid a fatal outcome of this pathology whose mortality, despite correct treatment, is high.

Systolic anterior motion of the anterior mitral valve leaflet begins in subclinical hypertrophic cardiomyopathy

AIMS

Anterior mitral valve leaflet (AMVL) elongation is detectable in overt and subclinical hypertrophic cardiomyopathy (HCM). We sought to investigate the dynamic motion of the aorto-mitral apparatus to understand the behaviour of the AMVL and the mechanisms of left ventricular outflow tract obstruction (LVOTO) predisposition in HCM.

METHODS AND RESULTS

Cardiovascular magnetic resonance imaging using a 1.5 Tesla scanner was performed on 36 HCM sarcomere gene mutation carriers without left ventricular hypertrophy (G+LVH-), 31 HCM patients with preserved ejection fraction carrying a pathogenic sarcomere gene mutation (G+LVH+), and 53 age-, sex-, and body surface area-matched healthy volunteers. Dynamic excursion of the aorto-mitral apparatus was assessed semi-automatically on breath-held three-chamber cine steady-state free precession images. Four pre-defined regions of interest (ROIs) were tracked: ROIPMVL: hinge point of the posterior mitral valve leaflet; ROITRIG: intertrigonal mitral annulus; ROIAMVL: AMVL tip; and ROIAAO: anterior aortic annulus. Compared with controls, normalized two-dimensional displacement-vs.-time plots in G+LVH- revealed subtle but significant systolic anterior motion (SAM) of the AMVL (P < 0.0001) and reduced longitudinal excursion of ROIAAO (P = 0.014) and ROIPMVL (P = 0.048). In overt and subclinical HCM, excursion of the ROITRIG/AMVL/PMVL was positively associated with the burden of left ventricular fibrosis (P < 0.028). As expected, SAM was observed in G+LVH+ together with reduced longitudinal excursion of ROITRIG (P = 0.049) and ROIAAO (P = 0.008).

CONCLUSION

Dyskinesia of the aorto-mitral apparatus, including SAM of the elongated AMVL, is detectable in subclinical HCM before the development of LVH or left atrial enlargement. These data have the potential to improve our understanding of early phenotype development and LVOTO predisposition in HCM.

Differentially expressed platelet activation-related genes in dogs with stage B2 myxomatous mitral valve disease

BACKGROUND

Peripheral blood carries a reservoir of mRNAs that regulate cardiac structure and function potential. Although it is well recognized that the typical symptoms of Myxomatous Mitral Valve Disease (MMVD) stage B2 are long-standing hemodynamic disorder and cardiac structure remodeling caused by mitral regurgitation, the transcriptomic alterations in blood from such dogs are not understood.

RESULTS

In the present study, comparative high-throughput transcriptomic profiling of blood was performed from normal control (NC) and naturally-occurring MMVD stage B2 (MMVD) dogs. Using Weighted Gene Co-expression Network Analyses (WGCNA), Gene Ontology (GO), and Kyoto Encyclopedia of Gene and Genomes (KEGG), we identified that the turquoise module was the most highly correlated with echocardiographic features and found 64 differentially expressed genes (DEGs) that were significantly enriched in platelet activation related pathways. Therefore, from the turquoise module, we selected five DEGs (MDM2, ROCK1, RIPK1, SNAP23, and ARHGAP35) that, according to real-time qPCR, exhibited significant enrichment in platelet activation related pathways for validation. The results showed that the blood transcriptional abundance of MDM2, ROCK1, RIPK1, and SNAP23 differed significantly (P < 0.01) between NC and MMVD dogs. On the other hand, Correlation Analysis revealed that MDM2, ROCK1, RIPK1, and SNAP23 genes negatively regulated the heart structure parameters, and followed the same trend as observed in WGCNA.

CONCLUSION

We screened four platelet activation related genes, MDM2, ROCK1, RIPK1, and SNAP23, which may be considered as the candidate biomarkers for the diagnosis of MMVD stage B2. These findings provided new insights into MMVD pathogenesis.

Defining the Spectrum of Hypoplastic Left Heart Syndrome (HLHS)

The 2021 International Paediatric and Congenital Cardiac Code and the Eleventh Revision of the International Classification of Diseases provide the following definition for hypoplastic left heart syndrome (HLHS): "Hypoplastic left heart syndrome (HLHS) is defined as a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch." Although HLHS with intact ventricular septum (HLHS + IVS) and HLHS with ventricular septal defect (HLHS + VSD) are different cardiac phenotypes, both of these lesions are part of the spectrum of HLHS.

Fluid-structure interaction and structural simulation of high acceleration effects on surgical repaired human mitral valve biomechanics

Mitral valve dynamics depend on force stability in the mitral leaflets, the mitral annulus, the chordae tendineae, and the papillary muscles. In chordal rupture conditions, the proper function of the valve disrupts, causing mitral regurgitation, the most prevalent valvular disease. In this study, Structural and FSI frameworks were employed to study valve dynamics in healthy, pathologic, and repaired states. Anisotropic, non-linear, hyper-elastic material properties applied to tissues of the valve while the first-order Ogden model reflected the best compatibility with the empirical data. Hemodynamic blood pressure of the cardiovascular system is applied on the leaflets as uniform loads varying by time, and exposure to high acceleration loads imposed on models. Immersed boundary method used for simulation of fluid in a cardiac cycle. In comparison between healthy and pathologic models, stress values and chordal tensions are increased, by nearly threefold and twofold, respectively. Stress concentration on leaflets is reduced by 75% after performing a successful surgical repair on the pathological model. Crash acceleration loads led to more significant stress and chordae tension on models, by 27% and 23%, respectively. It is concluded that a more sophisticated model could lead to a better understanding of human heart valve biomechanics in various conditions. If a preoperative plan is developed based on these modeling methods, the requirement for multiple successive repairs would be eliminated, operative times are shortened, and patient outcomes are improved.

Massive Mysteries

Papillary fibroelastomas are benign masses often originating from the endocardium of the aortic and mitral valves. Rarely, these neoplasms are found in areas of the heart embryonically distinct from the aortic and mitral valves. Diagnosis of a papillary fibroelastoma relies on multimodal imaging as well as histologic assessment. A case series of papillary fibroelastomas in unusual locations is presented, highlighting the role of multimodal imaging techniques in identifying these intra-cardiac masses. Differential diagnoses, imaging characteristics, histopathology, and preferred management strategies for cardiac masses are reviewed. The unique imaging qualities of cardiac masses are discussed.

Is Congenital Muscular Mitral-Aortic Discontinuity Another Feature of Obstructive Hypertrophic Cardiomyopathy? A Pathology Validation Study

Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disease at risk of sudden cardiac death and heart failure, even requiring heart transplantation. A "muscular mitral-aortic discontinuity" has been reported during surgery in the obstructive form. We aimed to validate these findings through pathological analysis of HCM heart specimens from the cardiovascular pathology tissue registry. Hearts with septal asymmetric HCM from sudden cardiac death, other causes of death, or heart transplantation were included. Sex-matched and age-matched patients without HCM served as controls. Gross and histologic analysis of the mitral valve (MV) apparatus and the mitral-aortic continuity were performed. Thirty HCM hearts (median age, 29.5 years; 15 men) and 30 controls (median age, 30.5 years; 15 men) were studied. In HCM hearts, a septal bulging was present in 80%, an endocardial fibrous plaque in 63%, a thickening of the anterior MV leaflet in 56.7%, and an anomalous insertion of papillary muscle in 10%. All cases but 1 (97%) revealed a myocardial layer overlapping the mitral-aortic fibrous continuity on the posterior side, corresponding to the left atrial myocardium. A negative correlation between the length of this myocardial layer and the age and the anterior MV leaflet length was found. The length did not differ between HCM and controls. Pathologic study of obstructive HCM hearts does not confirm the existence of a "muscular mitral-aortic discontinuity". An extension of left atrial myocardium, overlapping posteriorly the intervalvular fibrosa, is rather visible, and its length decreases with age, possibly as a consequence of left atrial remodeling. Our study highlights the fundamental role of thorough gross examination and the value of organ retention for further analysis in order to validate new surgical and imaging findings.

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.

Mitral valve rheumatoid nodule complicated by infective endocarditis

We report a case of a 73-year-old male with rheumatoid arthritis presenting with acute abdominal and back pain and rapidly developing multiorgan failure. A positive blood culture (Staphylococcus aureus, Candida species) followed by transoesophageal sonography established a diagnosis of mitral valve infective endocarditis. At the autopsy, the heart examination revealed fibrinous pericarditis and multiple small vegetations on the mitral valve. The mitral valve itself showed no significant damage. Surprisingly, the histological examination of the mitral valve showed granulomatous inflammation with central fibrinoid necrosis and peripheral palisade of histiocytes, with occasional giant cells and lymphocytic inflammatory infiltrate - findings consistent with a rheumatoid nodule. Infective vegetations were overlying the nodule. Due to its relative frequency, a possibility of cardiac involvement by rheumatoid arthritis and its potential infective complications should be considered in patients with appropriate history and clinical symptoms.

[Caseous calcification of the mitral annulus: case report and review of the literature]

Caseous calcification of the mitral annulus is an uncommon variant of mitral annular calcification. It appears as a round echodense mass containing central areas of echolucencies resembling liquefaction and with no flow in the central zone on color Doppler. In most cases it involves the posterior mitral annulus region, particularly in female subjects. The pathogenesis remains unclear: hypercholesterolemia and the dissolution of lipid-rich macrophages may be implicated in liquefaction necrosis. Transthoracic and transesophageal echocardiography represents the most reliable technique for diagnosis, whereas cardiac magnetic resonance imaging is the choice in doubtful cases. We report the case of an 82-year-old female patient describing different aspects of this particular clinical condition.

[Nonbacterial Thrombotic Endocarditis Caused by Antiphospholipid Antibody Syndrome:Report of a Case]

A 73-year-old woman with multiple episodes of cerebral infarction was diagnosed with nonbacterial thrombotic endocarditis( NBTE) and antiphospholipid antibody syndrome. Transesophageal echocardiography revealed highly mobile tumors both in the mitral and the aortic valve, and the patient underwent aortic and mitral valve replacement. Pathologically, tumor of the mitral valve was a thrombus, and that of the aortic valve was a papillary fibroelastoma. Early after surgery, a recurrent thrombus was found in the left atrium, but no organ embolization ensued, and the patient had no adverse event for six months thereafter. Surgery is indicated only in limited cases of NBTE, because postoperative anticoagulation therapy is hard to manage and clinical outcome is poor.

[A Rapidly Growing Cardiac Calcified Amorphous Tumor in a Peritoneal Dialysis Patient:Report of a Case]

A calcified amorphous tumor( CAT) is a non-neoplastic cardiac tumor, which has been reported to be associated with hemodialysis dependent end-stage renal disease. We report a case of CAT attached to mitral annular calcification (MAC) in the posterior leaflet annulus of the mitral valve in a 56-year-old man who had been receiving peritoneal dialysis for three years. The CAT grew to 10 mm long in a half year. Peritoneal dialysis dependent end-stage renal disease is associated with MAC. Additionally, MAC-related CAT has been reported growing rapidly. We should perform periodic echocardiography not only for hemodialysis patients but also for peritoneal dialysis patients. When CAT is diagnosed, operation should be performed early to prevent embolism such as cerebral infarction.

Management of Patients With Severe Mitral Annular Calcification: JACC State-of-the-Art Review

Mitral annular calcification (MAC) is a common and challenging pathologic condition, especially in the context of an aging society. Surgical mitral valve intervention in patients with MAC is difficult, with varying approaches to the calcified annular anatomy, and the advent of transcatheter valve interventions has provided additional treatment options. Advanced imaging provides the foundation for heart team discussions and management decisions concerning individual patients. This review focuses on the prognosis of, preoperative planning for, and management strategies for patients with MAC.

Streamline-based three-dimensional peak-velocity tracing of transvalvular flow using four-dimensional flow cardiac magnetic resonance imaging for left ventricular diastolic assessment in aortic regurgitation: a case report

BACKGROUND

Doppler transthoracic echocardiography is routinely performed to measure peak mitral inflow velocities in the assessment of left ventricular diastolic function. The limitations of echocardiography are well documented, but its accuracy in the measurement of transmitral peak velocity in the presence of aortic valve regurgitation has not yet been compared with four-dimensional flow cardiac magnetic resonance imaging. Four-dimensional flow cardiac magnetic resonance imaging offers time-resolved cross-sectional velocity information that can be used to investigate mitral inflow peak velocity. We present a case report demonstrating the potential superior capabilities of four-dimensional flow cardiac magnetic resonance imaging in accurately detecting mitral inflow velocities over Doppler echocardiography in patients with aortic regurgitation.

CASE PRESENTATION

A 67-year-old Caucasian female presented to our outpatient cardiology clinic with exertional dyspnea. Doppler transthoracic echocardiography identified moderate to severe aortic regurgitation. Mapping of mitral inflow peak velocities proved challenging with Doppler echocardiography. Additionally, four-dimensional flow cardiac magnetic resonance imaging with automated three-dimensional flow streamlines was performed, which allowed for more accurate detection of mitral inflow peak velocities.

CONCLUSIONS

Doppler echocardiography has a limited role in mitral inflow assessment where aortic regurgitation is present. In such cases, four-dimensional flow cardiac magnetic resonance imaging is an alternative imaging technique that may circumvent this issue and allow mitral inflow assessment.

[Mitral valve prolapse and mitral annulus disjunction: be aware of a potential arrhythmogenic substrate]

Mitral valve prolapse is a relatively common disease with a good overall prognosis. However, in specific clinical and instrumental contexts, patients at high risk of ventricular arrhythmias and sudden cardiac death can be identified. Female sex, history of palpitations or syncope, bi-leaflet myxomatous valve, ECG repolarization abnormalities in the inferior leads, complex ventricular arrhythmias, left ventricular fibrosis detected by cardiac magnetic resonance correlate with a higher risk clinical profile. Additionally, morpho-functional abnormalities of the mitral valve annulus, particularly mitral annulus disjunction, may cause a mechanical stretch at the inferior basal ventricular wall and posterior papillary muscles, predisposing to myocardial fibrosis and arrhythmias. A risk stratification strategy is needed to identify patients with mitral valve prolapse and/or mitral annulus disjunction at high risk of arrhythmias; however, few data are available. Further prospective multicenter studies are warranted, focusing on medical therapy, the role of implantable cardioverter-defibrillators for primary prevention, efficacy of targeted catheter ablation or mitral valve surgery.

Anterior versus posterior leaflet mitral valve repair: A propensity-matched analysis

OBJECTIVE

Mitral valve repair is superior to replacement for degenerative disease, but long-term outcomes of anterior versus posterior leaflet repair remain poorly defined. We propensity matched anterior and posterior repairs to compare long-term outcomes.

METHODS

Patients undergoing first-time degenerative mitral repair between 1992 and 2018 were identified. Primary outcome was overall survival. Secondary outcomes were postprocedural residual mitral regurgitation and reoperation. From 1025 patients, 1:1 propensity score matching was performed, yielding 309 anterior (isolated anterior = 85, bileaflet = 224) and 309 isolated posterior repairs.

RESULTS

Age was 58 ± 15 years, ejection fraction was 57% ± 10%, and matched groups were well balanced. Anterior repairs had longer bypass (122 ± 53 vs 109 ± 43 minutes, P = .001) and crossclamp (94 ± 44 vs 85 ± 62 minutes, P = .033) times. Mean residual mitral regurgitation grade was 0.44 (95% confidence interval, 0.24-0.65) for anterior repair and 0.30 (95% confidence interval, 0.13-0.47) for posterior repair (P = .31). Overall, 92% (569/618) of matched patients had no residual mitral regurgitation, with no differences in mitral regurgitation grade between groups (P = .77). Survival did not differ between anterior (10 years: 72% ± 7%; 15 years: 63% ± 7%) and posterior (10 years: 74% ± 7%; 15 years: 60% ± 8%) groups (log-rank P = .93). Linearized incidence of reoperation was 0.62% per patient-year, including 0.74% for anterior and 0.48% for posterior repairs. Cumulative incidence of reoperation at 15 years was 7.5% after anterior repair and 4.9% after posterior repair (Gray's test P = .26).

CONCLUSIONS

No long-term survival or reoperation difference was found between posterior and anterior repair. On the basis of these findings, surgeons at centers of excellence should aim for repair of both anterior and posterior leaflet pathology with the same decision-making threshold over valve replacement for degenerative mitral disease.

The genetic consequences of dog breed formation-Accumulation of deleterious genetic variation and fixation of mutations associated with myxomatous mitral valve disease in cavalier King Charles spaniels

Selective breeding for desirable traits in strictly controlled populations has generated an extraordinary diversity in canine morphology and behaviour, but has also led to loss of genetic variation and random entrapment of disease alleles. As a consequence, specific diseases are now prevalent in certain breeds, but whether the recent breeding practice led to an overall increase in genetic load remains unclear. Here we generate whole genome sequencing (WGS) data from 20 dogs per breed from eight breeds and document a ~10% rise in the number of derived alleles per genome at evolutionarily conserved sites in the heavily bottlenecked cavalier King Charles spaniel breed (cKCs) relative to in most breeds studied here. Our finding represents the first clear indication of a relative increase in levels of deleterious genetic variation in a specific breed, arguing that recent breeding practices probably were associated with an accumulation of genetic load in dogs. We then use the WGS data to identify candidate risk alleles for the most common cause for veterinary care in cKCs–the heart disease myxomatous mitral valve disease (MMVD). We verify a potential link to MMVD for candidate variants near the heart specific NEBL gene in a dachshund population and show that two of the NEBL candidate variants have regulatory potential in heart-derived cell lines and are associated with reduced NEBL isoform nebulette expression in papillary muscle (but not in mitral valve, nor in left ventricular wall). Alleles linked to reduced nebulette expression may hence predispose cKCs and other breeds to MMVD via loss of papillary muscle integrity.

As a consequence of selective breeding, specific disease-causing mutations have become more frequent in certain dog breeds. Whether the breeding practice also resulted in a general increase in the overall number of disease-causing mutations per dog genome is however not clear. To address this question, we compare the amount of harmful, potentially disease-causing, mutations in dogs from eight common breeds that have experienced varying degrees of intense selective breeding. We find that individuals belonging to the breed affected by the most intense breeding—cavalier King Charles spaniel (cKCs)—carry more harmful variants than other breeds, indicating that past breeding practices may have increased the overall levels of harmful genetic variation in dogs. The most common disease in cKCs is myxomatous mitral valve disease (MMVD). To identify variants linked to this disease we next characterize mutations that are common in cKCs, but rare in other breeds, and then investigate if these mutations can predict MMVD in dachshunds. We find that variants that regulate the expression of the gene NEBL in papillary muscles may increase the risk of the disease, indicating that loss of papillary muscle integrity could contribute to the development of MMVD.

Echocardiographic diagnosis of congenital double orifice mitral valve malformation: A case report

Double orifice mitral valve (DOMV) is a rare congenital valve malformation. Due to the insufficient understanding and awareness of its echocardiographic characteristics, there is a risk of misdiagnosis. Here, we report a case of echocardiographic diagnosis of congenital DOMV malformation in a 56-year-old male patient who visited our hospital for systematic physical examination, during which DOMV was not diagnosed. The following year, the patient visited our hospital again, and echocardiography showed two approximately circular orifices on the short axis view of the mitral valve. During diastole, two red Doppler blood flow signals were observed entering the left ventricle simultaneously. A small amount of blue Doppler signal revealed reflux into the left atrium during systole, leading to the diagnose of congenital heart disease with DOMV malformation, without other cardiac structural abnormality. Because the patient did not have obvious discomfort, he did not receive any special treatment and is regularly followed-up.

Surgical and Transcatheter Mitral Valve Replacement in Mitral Annular Calcification: A Systematic Review

Mitral annular calcification with mitral valve disease is a challenging problem that could necessitate surgical mitral valve replacement (SMVR). Transcatheter mitral valve replacement (TMVR) is emerging as a feasible alternative in high-risk patients with appropriate anatomy. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to December 25, 2019 for studies discussing SMVR or TMVR in patients with mitral annular calcification; 27 of 1539 articles were selected for final review. TMVR was used in 15 studies. Relevant data were available on 82 patients who underwent hybrid transatrial TMVR, and 354 patients who underwent transapical or transseptal TMVR. Outcomes on SMVR were generally reported as small case series (447 patients from 11 studies); however, 1 large study recently reported outcomes in 9551 patients. Patients who underwent TMVR had a shorter median follow-up of 9 to 12 months (range, in-hospital‒19 months) compared with patients with SMVR (54 months; range, in-hospital‒120 months). Overall, those undergoing TMVR were older and had higher Society of Thoracic Surgeons risk scores. SMVR showed a wide range of early (0%-27%; median 6.3%) and long-term mortality (0%-65%; median at 1 year, 15.8%; 5 years, 38.8%, 10 years, 62.4%). The median in-hospital, 30-day, and 1-year mortality rates were 16.7%, 22.7%, and 43%, respectively, for transseptal/transapical TMVR, and 9.5%, 20.0%, and 40%, respectively, for transatrial TMVR. Mitral annular calcification is a complex disease and TMVR, with a versatile option of transatrial approach in patients with challenging anatomy, offers a promising alternative to SMVR in high-risk patients. However, further studies are needed to improve technology, patient selection, operative expertise, and long-term outcomes.

Pulmonary Hypertension in Transcatheter Mitral Valve Repair for Secondary Mitral Regurgitation: The COAPT Trial

BACKGROUND

Pulmonary hypertension worsens prognosis in patients with heart failure (HF) and secondary mitral regurgitation (SMR).

OBJECTIVES

This study sought to determine whether baseline pulmonary hypertension influences outcomes of transcatheter mitral valve repair (TMVr) in patients with HF with SMR.

METHODS

In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, 614 patients with HF with moderate-to-severe or severe SMR were randomized to TMVr with the MitraClip plus guideline-directed medical therapy (GDMT) (n = 302) versus GDMT alone (n = 312). Baseline pulmonary artery systolic pressure (PASP) estimated from echocardiography was categorized as substantially increased (≥50 mm Hg) versus not substantially increased (<50 mm Hg).

RESULTS

Among 528 patients, 184 (82 TMVr, 102 GDMT) had PASP of ≥50 mm Hg (mean: 59.1 ± 8.8 mm Hg) and 344 (171 TMVr, 173 GDMT) had PASP of <50 mm Hg (mean: 36.3 ± 8.1 mm Hg). Patients with PASP of ≥50 mm Hg had higher 2-year rates of death or HF hospitalization (HFH) compared to those with PASP of <50 mm Hg (68.8% vs. 49.1%; adjusted hazard ratio: 1.52; 95% confidence interval: 1.17 to 1.97; p = 0.002). Rates of death or HFH were reduced by TMVr versus GDMT alone, irrespective of baseline PASP (p_interaction = 0.45). TMVr reduced PASP from baseline to 30 days to a greater than GDMT alone (adjusted least squares mean: -4.0 vs. -0.9 mm Hg; p = 0.006), a change that was associated with reduced risk of death or HFH between 30 days and 2 years (adjusted hazard ratio: 0.91 per -5 mm Hg PASP; 95% confidence interval: 0.86 to 0.96; p = 0.0009).

CONCLUSIONS

Elevated PASP is associated with a worse prognosis in patients with HF with severe SMR. TMVr with the MitraClip reduced 30-day PASP and 2-year rates of death or HFH compared with GDMT alone, irrespective of PASP.

Activation of the Interleukin-33/ST2 Pathway Exerts Deleterious Effects in Myxomatous Mitral Valve Disease

Mitral valve disease (MVD) is a frequent cause of heart failure and death worldwide, but its etiopathogenesis is not fully understood. Interleukin (IL)-33 regulates inflammation and thrombosis in the vascular endothelium and may play a role in the atherosclerotic process, but its role in mitral valve has not been investigated. We aim to explore IL-33 as a possible inductor of myxomatous degeneration in human mitral valves. We enrolled 103 patients suffering from severe mitral regurgitation due to myxomatous degeneration undergoing mitral valve replacement. Immunohistochemistry of the resected leaflets showed IL-33 and ST2 expression in both valve interstitial cells (VICs) and valve endothelial cells (VECs). Positive correlations were found between the levels of IL-33 and molecules implicated in the development of myxomatous MVD, such as proteoglycans, extracellular matrix remodeling enzymes (matrix metalloproteinases and their tissue inhibitors), inflammatory and fibrotic markers. Stimulation of single cell cultures of VICs and VECs with recombinant human IL-33 induced the expression of activated VIC markers, endothelial–mesenchymal transition of VECs, proteoglycan synthesis, inflammatory molecules and extracellular matrix turnover. Our findings suggest that the IL-33/ST2 system may be involved in the development of myxomatous MVD by enhancing extracellular matrix remodeling.

Factors affecting the urinary aldosterone-to-creatinine ratio in healthy dogs and dogs with naturally occurring myxomatous mitral valve disease

BACKGROUND

Chronic renin-angiotensin-aldosterone system (RAAS) activation in course of heart diseases contributes to cardiac remodeling and heart failure. Myxomatous mitral valve disease (MMVD) is characterized by different stages of severity and trend of RAAS activity during the course of the disease is still uncertain. The urinary aldosterone-to-creatinine ratio (UAldo:C) has been proven to reflect RAAS activation in dogs and might be a useful marker in monitoring therapy and disease progression, but data about this parameter need to be expanded. The objective of this study was to evaluate the UAldo:C in healthy dogs and dogs with naturally occurring MMVD, and to investigate the relationships between this parameter and clinical, echocardiographic and laboratory variables.

RESULTS

The study population consisted of 149 dogs: 49 healthy and 100 MMVD dogs (45 stage B1, 13 stage B2 and 42 stage C). Urinary aldosterone-to-creatinine ratio was not significantly different among healthy and MMVD dogs of any stages. Breed, sex and age showed a significant impact on UAldo:C. In particular, Chihuahua and Cavalier King Charles spaniel showed significantly higher UAldo:C than other breeds, as well as intact females than other genders. In stage C dogs, UAldo:C appeared to be increased by spironolactone and was positively associated with furosemide dose (P = 0.024). Aldosterone breakthrough (ABT) appeared to occur in 36% (8/22) of stage C dogs not receiving spironolactone. A significant positive association between UAldo:C and left atrium-to-aortic root ratio (LA/Ao) was found.

CONCLUSIONS

Individual factors such as breed, sex and age appeared to influence UAldo:C, and therapy seemed to add further variability. In the light of these results, comparing the UAldo:C of a single patient with a population-based reference value might lead to wrong interpretations and an individual monitoring should be considered. The prevalence of ABT in the present study (36%) was in line with those previously reported. However, due to the high individual variability of UAldo:C found in the study, even this result should be re-evaluated in the setting of an individual longitudinal approach. The positive association between UAldo:C and LA/Ao supports the mutual relationship between RAAS and cardiac remodeling.

Tenascin C promotes valvular remodeling in two large animal models of ischemic mitral regurgitation

Ischemic mitral regurgitation (MR) is a frequent complication of myocardial infarction (MI) characterized by adverse remodeling both at the myocardial and valvular levels. Persistent activation of valvular endothelial cells leads to leaflet fibrosis through endothelial-to-mesenchymal transition (EMT). Tenascin C (TNC), an extracellular matrix glycoprotein involved in cardiovascular remodeling and fibrosis, was also identified in inducing epithelial-to-mesenchymal transition. In this study, we hypothesized that TNC also plays a role in the valvular remodeling observed in ischemic MR by contributing to valvular excess EMT. Moderate ischemic MR was induced by creating a posterior papillary muscle infarct (7 pigs and 7 sheep). Additional animals (7 pigs and 4 sheep) served as controls. Pigs and sheep were sacrificed after 6 weeks and 6 months, respectively. TNC expression was upregulated in the pig and sheep experiments at 6 weeks and 6 months, respectively, and correlated well with leaflet thickness (R = 0.68; p < 0.001 at 6 weeks, R = 0.84; p < 0.001 at 6 months). To confirm the translational potential of our findings, we obtained mitral valves from patients with ischemic cardiomyopathy presenting MR (n = 5). Indeed, TNC was also expressed in the mitral leaflets of these. Furthermore, TNC induced EMT in isolated porcine mitral valve endothelial cells (MVEC). Interestingly, Toll-like receptor 4 (TLR4) inhibition prevented TNC-mediated EMT in MVEC. We identified here for the first time a new contributor to valvular remodeling in ischemic MR, namely TNC, which induced EMT through TLR4. Our findings might set the path for novel therapeutic targets for preventing or limiting ischemic MR.

Comparative transcriptomic profiling of myxomatous mitral valve disease in the cavalier King Charles spaniel

BACKGROUND

Almost all elderly dogs develop myxomatous mitral valve disease by the end of their life, but the cavalier King Charles spaniel (CKCS) has a heightened susceptibility, frequently resulting in death at a young age and suggesting that there is a genetic component to the condition in this breed. Transcriptional profiling can reveal the impact of genetic variation through differences in gene expression levels. The aim of this study was to determine whether expression patterns were different in mitral valves showing myxomatous degeneration from CKCS dogs compared to valves from non-CKCS dogs.

RESULTS

Gene expression patterns in three groups of canine valves resulted in distinct separation of normal valves, diseased valves from CKCS and diseased valves from other breeds; the latter were more similar to the normal valves than were the valves from CKCS. Gene expression patterns in diseased valves from CKCS dogs were quite different from those in the valves from other dogs, both affected and normal. Patterns in all diseased valves (from CKCS and other breeds) were also somewhat different from normal non-diseased samples. Analysis of differentially expressed genes showed enrichment in GO terms relating to cardiac development and function and to calcium signalling canonical pathway in the genes down-regulated in the diseased valves from CKCS, compared to normal valves and to diseased valves from other breeds. F2 (prothrombin) (CKCS diseased valves compared to normal) and MEF2C pathway activation (CKCS diseased valves compared to non-CKCS diseased valves) had the strongest association with the gene changes. A large number of genes that were differentially expressed in the CKCS diseased valves compared with normal valves and diseased valves from other breeds were associated with cardiomyocytes including CASQ2, TNNI3 and RYR2.

CONCLUSION

Transcriptomic profiling identified gene expression changes in CKCS diseased valves that were not present in age and disease severity-matched non-CKCS valves. These genes are associated with cardiomyocytes, coagulation and extra-cellular matrix remodelling. Identification of genes that vary in the CKCS will allow exploration of genetic variation to understand the aetiology of the disease in this breed, and ultimately development of breeding strategies to eliminate this disease from the breed.

Outcomes After Transcatheter Mitral Valve-in-Valve Replacement in Patients With Degenerated Bioprosthesis: A Single-Center Experience

BACKGROUND

This study sought to describe a single center's experience with transcatheter mitral valve-in-valve (TM-ViV) implantation.

METHODS

Consecutive patients who had TM-ViV due to degenerative biological valve prosthesis at a single center during a 4-year period were identified from a prospectively maintained database. Operative outcomes were assessed both in-hospital and at 30 days. The primary outcome was in-hospital mortality. Secondary outcomes included valve function, functional status, and quality of life at follow-up.

RESULTS

Mean (± standard deviation) patient age was 69 ± 12 years and all patients were high risk for redo surgery (STS risk score, 9.6 ± 6.2%). The primary mechanism of bioprosthetic valve failure was stenosis in 7 patients (47%) and regurgitation in 8 patients (53%). Mean duration between mitral valve replacement (MVR) and transcatheter MVR was 89 months (range, 66-72 months). Failed bioprosthetic valves were replaced with Sapien XT (n = 10; 67%), Sapien (n = 4; 26%), or Sapien S3 valves (n = 1; 7%) (all valves manufactured by Edwards Lifesciences). Procedural success was 100%. No intraoperative deaths were recorded. Postimplantation valve hemodynamics was satisfactory, with a significant improvement in mean valvular gradient (Δ = -12 mm Hg; P<.001) and mitral valve area (Δ = 0.9 cm²; P<.01). At 30-day follow-up, no reports of death, disabling stroke, or rehospitalization for cardiac reasons was recorded. Health status scores were available for 11 of the 15 study patients (73%). Except for 1 patient, significant improvements were seen for all components of the health assessment survey.

CONCLUSIONS

TM-ViV for failing biological mitral prosthesis can be performed with minimal operative morbidity and acceptable mid-term clinical and hemodynamic outcomes.

Morphological and functional characteristics of mitral annular calcification and their relationship to stroke

BACKGROUND

Mitral annular calcification (MAC) is associated with risk of stroke. This study aimed to define the morphological and functional characteristics of MAC that are related to stroke.

METHODS

A total of 460 subjects with MAC from transthoracic echocardiography in a single center from 2012 to 2016 was retrospectively reviewed. Subjects were classified into two groups according to history of stroke [Group 1 (n = 366): without stroke; Group 2 (n = 94): with stroke]. Morphological and functional features of MAC on echocardiogram were scored from 0 to 3 according to MAC mobility, presence of echodense mass with central echolucencies in the periannular region suggesting caseous necrosis, and functional stenosis.

RESULTS

Significantly more patients in group 2 were men and had history of diabetes mellitus, dyslipidemia, atrial fibrillation, or infective endocarditis. Although MAC thickness and extent did not differ between the two groups, group 2 showed a considerably higher MAC score than group 1 (0.50 ± 0.77 vs. 0.23 ±0.52 p<0.001) as a result of the higher prevalence of each component in group 2 [mobility (22 vs. 11%, p = 0.003), echodense mass with central areas of echolucencies suggesting caseous necrosis (23 vs. 7%, p<0.001), and functional mitral stenosis (12 vs. 7%, p = 0.042)]. On logistic regression analysis, MAC score was independently associated with stroke and showed significant incremental value to demographic factors and comorbidities in association with stroke in a consecutive manner.

CONCLUSIONS

In conclusion, morphological and functional characteristics of MAC had incremental value in association with stroke over traditional risk factors. MAC score consisting of MAC mobility, typical echodense mass with central echolucencies suggesting caseous necrosis, and functional mitral stenosis was independently associated with stroke. MAC with high-risk features may act as a source of stroke or more potent composite surrogate markers for stroke-related risk factors.

Antioxidative enzyme activity and total antioxidant capacity in serum of dogs with degenerative mitral valve disease

This study was designed to evaluate the antioxidative status of serum by measuring its total antioxidant capacity, as well as the antioxidant enzyme activity (superoxide dismutase, catalase, and glutathione reductase), in dogs with various stages of degenerative mitral valve disease (DMVD) compared to healthy controls. In total, 71 client-owned dogs in different stages of DMVD, which included healthy controls, took part in the study. Following an anamnesis, clinical examination, standard transthoracic echocardiograpic examination, chest X-ray, complete blood (cell) count, and serum biochemistry, dogs were divided into 2 study groups. Blood was drawn from each dog once at the time of presentation and selected antioxidant parameters were measured using commercially available assay kits. The activity of superoxide dismutase gradually decreased in the more advanced stages of DMVD, while the activity of catalase was significantly higher in the group of dogs with asymptomatic DMVD compared to healthy controls and dogs with symptomatic DMVD. No significant changes were noted in total antioxidant capacity and the activity of glutathione reductase. Results suggested that DMVD has a significant impact on the activity of superoxide dismutase and catalase in the serum of the tested dogs. Knowledge of changes in the activity of antioxidative enzymes may warrant further studies, possibly to evaluate the potential role of compounds with antioxidative properties in the clinical outcome of dogs with DMVD.

Minimally Invasive Hybrid Approach to High Risk Mitral Disease With Severe Mitral Annular Calcification

Severe circumferential mitral annular calcification (MAC) remains a significant challenge, complicating surgical treatment of mitral valve disease. Transcatheter treatment options are attractive; however, they remain fraught with risks of annular fixation, paravalvular leak, atrioventricular-groove disruption, and left-ventricular outflow tract obstruction. We describe a novel minimally invasive hybrid technique of transcatheter mitral valve replacement in a patient with severe circumferential MAC.

Towards safe and efficient preoperative planning of transcatheter mitral valve interventions

OBJECTIVE OF THE STUDY

Transcatheter mitral valve interventions are emerging as a viable alternative for patients at high risk. Two key aspects are crucial during the preoperative planning: left ventricular outflow tract assessment and anatomical analysis. Given that the manual anatomical analysis is time-consuming, an automated approach may introduce efficiency during preoperative planning. In this study, we present an automatic method to detect the mitral valve annulus and discuss possible implementation of this method in clinical practice.

PATIENTS

This retrospective study used the data of 71 patients collected from multiple centra. The mean age of this cohort was 74.2±13.1 years, and 56.1% of the patients were female and 43.9% male.

MATERIALS AND METHODS

We trained three deep learning models to segment the area around the mitral valve annulus. In a post-processing step, we extracted the mitral valve annulus from this segmentation. As a final step, clinically relevant measurements such as 2D perimeter, trigone-to-trigone (TT) distance, septal-to-lateral (SL) distance and commissure-to-commissure (IC) distance were derived from the predicted mitral valve annulus. The method was cross-validated with k-folding.

RESULTS

The predicted measurements showed excellent correlation with the manually obtained clinical measurements: 2D perimeter: R²=0.93, TT-distance: R²=0.86, SL-distance: R²=0.86 and IC-distance: R²=0.90. The total analysis time per patient of the automatic method was less than 1 second, which is an enormous speed-up as compared to the manual process (25minutes).

CONCLUSION

The efficiency and accuracy of the proposed method give the confidence to move towards implementation of this technology in clinical practice. We propose a possible implementation of this method in clinical practice, which, in our opinion, will facilitate safe and efficient preoperative planning of transcatheter mitral valve interventions.

Mitral annular calcification is associated with atrial fibrillation and major cardiac adverse events in atrial fibrillation patients: A systematic review and meta-analysis

BACKGROUND

The incidence of atrial fibrillation (AF) varies from 5.4% to 47.1% in patients with mitral annulus calcification (MAC). We conducted a systematic review and meta-analysis on the association between MAC and AF, as well as the relation between MAC and major cardiac adverse events (MACEs) in AF patients.

METHODS

We conducted comprehensive search for literature on associations between MAC and AF using the following databases: MEDLINE, PubMed, Embase, and the Web of Science. The pooled odds ratio (OR) or relative risk and the corresponding 95% confidence intervals (CIs) were calculated to assess the relationship between MAC and AF, as well as the rates of MACEs in AF patients with or without MAC.

RESULTS

Thirteen studies met our eligibility criteria on associations between MAC and AF, including 6232 patients with MAC and 15,199 patients without MAC. Moreover, 5 studies met our eligibility criteria on the rates of MACEs in AF patients with or without MAC. The pooled analysis demonstrated a statistically significant increased risk of development of incident AF in patients with MAC than those without MAC (random effects OR: 2.34; 95% CI: 1.91, 2.85; P = .000). And the pooled analysis demonstrated a statistically significant increased risk of development of MACEs in AF patients with MAC (random effects OR: 2.34; 95% CI: 1.24, 4.41; P = .009).

CONCLUSION

MAC was independently associated with AF and AF patients with MAC were at greater risk for cardiovascular and cerebrovascular events.

Effect of pimobendan on physical fitness, lactate and echocardiographic parameters in dogs with preclinical mitral valve disease without cardiomegaly

Pimobendan has gained enormous importance in the treatment of mitral valve disease in dogs. The current consensus statement of the American College of Veterinary Internal Medicine (ACVIM) recommends a treatment for dogs with symptomatic disease and dogs with asymptomatic disease with radiographic and echocardiographic signs of cardiomegaly. To investigate whether these dogs also benefit from a therapy with pimobendan, 21 dogs with mitral valve disease ACVIM B1 underwent a standardized submaximal exercise test on a treadmill. In this double-blinded and randomized study, the animals were divided into two groups, one receiving pimobendan and the other a placebo. At the first visit and at every follow-up appointment (at days 90 and 180), heart rate during the complete exercise test and lactate before and after running were measured. In addition to this, a questionnaire was completed by the dogs’ owners and all dogs were given an echocardiographic examination to detect any changes and to observe if the disease had progressed. Due to the diagnosis of leishmaniosis, one dog in the pimobendan group was retrospectively removed from the study so that 20 dogs were included for statistical analysis. No differences were observed at any time between the pimobendan-group and the placebo-group regarding heart rate. At day 180, the increase in lactate after exercise was significantly lower than in the placebo-group. The increase in the pimobendan-group at day 180 was lower than at day 90. Most of the dog owners from the pimobendan-group declared that their dogs were more active at day 90 (6/10) and at day 180 (8/10), while most dog owners from the placebo-group observed no changes regarding activity at day 90 (8/10) and day 180 (6/10). It can be concluded that the results of this study indicate that some dogs with mitral valve disease ACVIM B1 might benefit from a therapy with pimobendan.

Idiopathic degenerative thoracic aneurysms are associated with increased aortic medial amyloid

Objective: To explore the relationship of aortic medial amyloid with biochemical and micromechanical properties of the aortic wall in aneurysm patients. Methods: Human aortic tissues removed during aneurysm surgery from tricuspid (idiopathic degenerative aneurysm, DA) and bicuspid valve (BAV) patients were subjected to oscillatory nanoindentation experiments to determine localised mechanical properties of the tissue (shear storage modulus, G´ and shear loss modulus, G˝). Collagen, elastin, matrix metalloproteinase 2 and glycosaminoglycans concentrations were determined, along with relative levels of aortic medial amyloid-related factors (medin, milk fat globule-EGF factor 8, oligomers and fibrils). Measurements were combined with clinical data and statistical analyses performed. Results: The DA cohort can be divided based on their phenotype. One group shared similar characteristics with BAV patients, termed bicuspid like phenotype-tricuspid valve. The second group had high amyloid oligomer species present with a significantly lower G´ (p = .01), indicative of reduced elastic response of the tissue, termed amyloid-rich. Conclusions: We identified a group of DA patients with high amyloid oligomers and altered micromechanical and structural properties of the vessel wall. We propose these findings as a cause for aneurysm formation in these patients. Amyloid is not found in BAV patients, suggesting at least two distinct mechanisms for pathogenesis.

Evaluation of canine 2D cell cultures as models of myxomatous mitral valve degeneration

The utility of cells cultured from the mitral valve as models of myxomatous diseases needs to be properly validated. In this study valve interstitial cells (VICs) and valve endothelial cells (VECs) were cultured from normal and diseased canine mitral valves in 2% (v/v) or 10% FBS media, in the presence of TGFβ1, 2 and 3, the TGFβ RI kinase inhibitor SB431542 and TGFβ neutralising antibodies, 5HT and the 5HT2RB antagonist LY272015. Cultures were examined by morphology, transcriptomic profiling, protein expression of the cell specific markers αSMA and SM22α (VICs), and CD31 (VECs), deposition of proteoglycans (PG), the PG versican, and the TGFβs themselves. VECs derived from normal valves were CD31+/αSMA-, but those from diseased valves were αSMA+, indicating endothelial-to-mesenchymal (EndoMT) transition had occurred. The TGFβs induced EndoMT in normal VECs, and this was abolished by SB431542, with significant changes in αSMA, CD31 and HAS2 expression (P<0.05). Normal VICs cultured in 10% FBS media were αSMA+ (activated myofibroblast (disease) phenotype), but were αSMA- when grown in 2% FBS. VICs from diseased dogs were αSMA+ in 2% FBS (retention of the activated myofibroblast disease phenotype), with significantly increased TGFβ1 expression (P<0.05) compared to normal cells. Treatment of normal and diseased VICs with the TGFβs significantly increased expression of αSMA, SM22α, versican, the TGFβs themselves, and deposition of PGs (P<0.05), with TGFβ1 being the most potent activator. These effects were either abolished or markedly reduced by SB431542 and a pan-TGFβ neutralizing antibody (P<0.05). SB431542 also markedly reduced αSMA expression in VICs from diseased valves, but 5HT and LY272015 had no effect on VIC phenotype. Transcriptomic profiling identified clear differences in gene expression for the different conditions and treatments that partially matched that seen in native diseased valve tissue, including changes in expression of ACTA2 (αSMA), 5HTR2B, TAGLN (SM22α) and MYH10 (SMemb), gene ontology terms and canonical signalling pathways. Normal and diseased VICs and normal VECs from canine mitral valves can be successfully grown in culture with retention of phenotype, which can be manipulated using TGFβ1 and the TGFβ RI kinase inhibitor SB431542. This optimized cell system can now be used to model MMVD to elucidate disease mechanisms and identify key regulators of disease progression.

Vitamin D-binding protein and vitamin D receptor genotypes and 25-hydroxyvitamin D levels are associated with development of aortic and mitral valve calcification and coronary artery diseases

To assess the association between vitamin D-Binding Protein (VDBP rs7041T>G) and vitamin D receptor (VDR rs1544410G>A) gene polymorphisms with susceptibility to cardiovascular diseases in population from west of Iran. Two hundred forty-nine individuals with cardiovascular disease (92 with aortic and Mitral Valves Calcification (AMVC) and 157 with Coronary Artery Diseases (CAD) that their diseases were confirmed by echocardiography and angiography and unrelated 182 healthy controls (gender and age-matched) were selected for this case-control study. The VDR 1544410G>A, and VDBP 7041T>G genotyping were detected by PCR-RFLP, serum vitamin D and lipid concentrations were measured by ELISA and enzyme assay, respectively. The VDR rs1544410G>A gene is a strong risk factor for CAD (OR = 1.28, p = 0.002) and the dominant genotype (T/G+G/G) of VDBP 7041 T>G SNP plays a protective role (OR = 0.67, p = 0.003) in AMVC development in studied population. In addition, lower level of vitamin D strongly increased the risk of CAD (15 ± 11.02 vs. 21.3 ± 18 μg/L, p = 0.043) and AMVC (12.1 ± 13.1 vs.21.3 ± 18 μg/L, p = 0.014) development in individuals carrying T/T genotype of VDBP 7041 T>G gene polymorphism. There was a strong interaction between A allele VDR rs1544410 and G allele of VDBP rs7041 genes in a protective role (OR = 0.74, p = 0.044) in AMVC patients). CAD and AMVC patients were deficient in vitamin D, i.e. their level of vitamin D was strongly lower than that in the control group. Our findings for the first time indicated that there is a strong association between vitamin D deficiency, lipid profile and the VDR rs1544410G>A and rs7T41>G VDBP genes polymorphisms. These interactions may be one of the important factors for CAD and AMVC incidence.