Prevalence and clinical outcome of mitral-valve prolapse

Characteristic Histopathological Findings and Cardiac Arrest Rhythm in Isolated Mitral Valve Prolapse and Sudden Cardiac Death

Background

The association between mitral valve prolapse (MVP) and sudden death remains controversial. We aimed to describe histopathological changes in individuals with autopsy‐determined isolated MVP (iMVP) and sudden death and document cardiac arrest rhythm.

Methods and Results

The Australian National Coronial Information System database was used to identify cases of iMVP between 2000 and 2018. Histopathological changes in iMVP and sudden death were compared with 2 control cohorts matched for age, sex, height, and weight (1 group with noncardiac death and 1 group with cardiac death). Data linkage with ambulance services provided cardiac arrest rhythm for iMVP cases. From 77 221 cardiovascular deaths in the National Coronial Information System database, there were 376 cases with MVP. Individual case review yielded 71 cases of iMVP. Mean age was 49±18 years, and 51% were women. Individuals with iMVP had higher cardiac mass (447 g versus 355 g; P<0.001) compared with noncardiac death, but similar cardiac mass (447 g versus 438 g; P=0.64) compared with cardiac death. Individuals with iMVP had larger mitral valve annulus compared with noncardiac death (121 versus 108 mm; P<0.001) and cardiac death (121 versus 110 mm; P=0.002), and more left ventricular fibrosis (79% versus 38%; P<0.001) compared with noncardiac death controls. In those with iMVP and witnessed cardiac arrest, 94% had ventricular fibrillation.

Conclusions

Individuals with iMVP and sudden death have increased cardiac mass, mitral annulus size, and left ventricular fibrosis compared with a matched cohort, with cardiac arrest caused by ventricular fibrillation. The histopathological changes in iMVP may provide the substrate necessary for development of malignant ventricular arrhythmias.

Mitral annulus morphometry in degenerative mitral regurgitation phenotypes

OBJECTIVES

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

METHODS AND RESULTS

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

CONCLUSION

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

Prevalence of mitral annular disjunction in patients with mitral valve prolapse and severe regurgitation

Mitral annular disjunction (MAD) is routinely diagnosed by cardiac imaging, mostly by echocardiography, and shown to be a risk factor for ventricular arrhythmias. While MAD is associated with mitral valve (MV) prolapse (MVP), it is unknown which patients with MAD are at higher risk and which additional imaging features may help identify them. The value of cardiac computed tomography (CCT) for the diagnosis of MAD is unknown. Accordingly, we aimed to: (1) develop a standardized CCT approach to identify MAD in patients with MVP and severe mitral regurgitation (MR); (2) determine its prevalence and identify features that are associated with MAD in this population. We retrospectively studied 90 patients (age 63 ± 12 years) with MVP and severe MR, who had pre-operative CCT (256-slice scanner) of sufficient quality for analysis. The presence and degree of MAD was assessed by rotating the view plane around the MV center to visualize disjunction along the annulus. Additionally, detailed measurements of MV apparatus and left heart chambers were performed. Univariate logistic regression analysis was performed to determine which parameters were associated with MAD. MAD was identified in 18 patients (20%), and it was typically located adjacent to a prolapsed or flail mitral leaflet scallop. Of these patients, 75% had maximum MAD distance > 4.8 mm and 90% > 3.8 mm. Female gender was most strongly associated with MAD (p = 0.04). Additionally, smaller end-diastolic mitral annulus area (p = 0.045) and longer posterior leaflet (p = 0.03) were associated with greater MAD. No association was seen between MAD and left ventricular size and function, left atrial size, and papillary muscle geometry. CCT can be used to readily detect MAD, by taking advantage of the 3D nature of this modality. A significant portion of MVP patients referred for mitral valve repair have MAD. The presence of MAD is associated with female gender, smaller annulus size and greater posterior leaflet length.

Percutaneous mitral valve repair: the necessity to redefine secondary mitral regurgitation

Interest in percutaneous mitral valve repair has increased during recent years. This is mainly driven by the significant number of patients being declined for mitral valve surgery because of a high risk of surgery-related complications or death. In this subset of patients, percutaneous edge-to-edge repair using the MitraClip device (Abbott, Menlo Park, CA, USA) has become an established treatment option, proven to be safe, efficient and associated with improved functional status. In contrast to primary mitral regurgitation (MR), clinical outcomes after mitral valve surgery appear to be less favourable as regards secondary MR due to heart failure. In the MITRA-FR and COAPT trials, patients with moderate to severe and severe secondary MR with reduced left ventricular function received either medical treatment (control group) or MitraClip implantation plus medical treatment (device group). Results were conflicting, with only the COAPT trial showing better clinical outcomes in the device group. However, both trials are now seen as complementary and provide useful information especially regarding patient selection for MitraClip therapy. The goal of this review is to delineate which subset of patients with secondary MR will potentially benefit from percutaneous mitral valve repair.

The ALPIM (Anxiety, Laxity, Pain, Immune, and Mood) Syndrome in Adolescents and Young Adults: A Cohort Study

OBJECTIVE

ALPIM (anxiety, laxity, pain, immune, and mood) syndrome has been previously described in adults. The authors aimed to identify its occurrence in adolescents and confirm its existence in adults. Given the association of the disorder with somatic symptoms, separation anxiety disorder (SAD) was explored as an ALPIM comorbidity.

METHODS

Medical records of patients aged 11-34 with a diagnosis of depression or anxiety (panic disorder, SAD, social anxiety or generalized anxiety disorder) seen during a 1-year period were reviewed. Data were collected on the presence of ALPIM comorbidities. Analyses were conducted to detect their co-occurrence and evaluate possible predictors of the ALPIM syndrome.

RESULTS

Inclusion criteria were met by 185 patient charts. A significant association was observed between the ALPIM comorbidities with 20 study subjects (10.8%) meeting criteria for ALPIM syndrome (patients with one or more diagnoses from each ALPIM domain). Patients with SAD had increased odds of being diagnosed with ALPIM (odds ratio=7.14, 95% CI=2.48-20.54, p<0.001). Neither major depression nor generalized anxiety disorder was found to be predictive of ALPIM syndrome. There was no difference in the prevalence of ALPIM-related comorbidities between study subjects <18 years old compared with those ≥18 years old.

CONCLUSIONS

These findings reestablish the association of distinct psychiatric and nonpsychiatric conditions described as the ALPIM syndrome. Furthermore, the syndrome may present during adolescence. SAD may be an independent predictive factor for the occurrence of ALPIM syndrome. Patients with individual ALPIM comorbidities should be assessed for the syndrome, especially if they have a history of SAD.

Desert hedgehog-primary cilia cross talk shapes mitral valve tissue by organizing smooth muscle actin

Non-syndromic mitral valve prolapse (MVP) is the most common heart valve disease affecting 2.4% of the population. Recent studies have identified genetic defects in primary cilia as causative to MVP, although the mechanism of their action is currently unknown. Using a series of gene inactivation approaches, we define a paracrine mechanism by which endocardially-expressed Desert Hedgehog (DHH) activates primary cilia signaling on neighboring valve interstitial cells. High-resolution imaging and functional assays show that DHH de-represses smoothened at the primary cilia, resulting in kinase activation of RAC1 through the RAC1-GEF, TIAM1. Activation of this non-canonical hedgehog pathway stimulates α-smooth actin organization and ECM remodeling. Genetic or pharmacological perturbation of this pathway results in enlarged valves that progress to a myxomatous phenotype, similar to valves seen in MVP patients. These data identify a potential molecular origin for MVP as well as establish a paracrine DHH-primary cilium cross-talk mechanism that is likely applicable across developmental tissue types.

Gender-specific differences in valvular heart disease

The development of new devices and treatment options has greatly increased the interest in heart valve diseases. In this context, the consideration of gender differences in diagnosis, treatment success, and prognosis is of great importance. Available data show that women and men with heart valve disease have different risk profiles, which have a significant impact on treatment outcomes and prognosis.

It is the purpose of this review article to give an overview of gender-related differences in patients with valvular heart disease, regarding clinical presentation, treatment, and outcomes. In light of the emerging treatment possibilities, future research should emphasize the role of gender since both sexes benefit from tailored management.

A single nucleotide deletion resulting in a frameshift in exon 4 of TAB2 is associated with a polyvalular syndrome

OBJECTIVE

Polyvalvularmyxomatous degeneration is a rare clinical condition. A 51-year-old male patient presented at our centre with all four heart valves with myxomatous degeneration and severe mitral and aortic regurgitation due to leaflet prolapse. The patient referred five further family members with valvular heart disease at different stages of presentation. The aim of this study was to investigate the genetic basis of this familial polyvalvularmyxomatous degeneration which was associated with mild dysmorphic facial anomalies and short stature.

DESIGN

A detailed family history was recorded. Nine members of the family, affected or not by valvular heart disease, were studied clinically, echocardiographically and by detailed genetic analyses.

RESULTS

Six of the nine family members had echocardiographic features of different degrees of degenerative heart valve disease. In addition, the affected subjects shared similar mild dysmorphic facial anomalies and short stature. Exome sequencing identified a rare heterozygous single nucleotide deletion in the TAB2 gene in all affected family members, which was absent in the unaffected members.

CONCLUSIONS

A variant in the TAB2 gene is proposed as the cause of syndromic congenital heart disease, displaying congenital myxomatous degenerative heart valve disease, mild dysmorphic fascial anomalies and short stature in this family.

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

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

Development and Ex Vivo Validation of Novel Force-Sensing Neochordae for Measuring Chordae Tendineae Tension in the Mitral Valve Apparatus Using Optical Fibers With Embedded Bragg Gratings

Few technologies exist that can provide quantitative data on forces within the mitral valve apparatus. Marker-based strain measurements can be performed, but chordal geometry and restricted optical access are limitations. Foil-based strain sensors have been described and work well, but the sensor footprint limits the number of chordae that can be measured. We instead utilized fiber Bragg grating (FBG) sensors-optical strain gauges made of 125 μm diameter silica fibers-to overcome some limitations of previous methods of measuring chordae tendineae forces. Using FBG sensors, we created a force-sensing neochord (FSN) that mimics the natural shape and movement of native chordae. FBG sensors reflect a specific wavelength of light depending on the spatial period of gratings. When force is applied, the gratings move relative to one another, shifting the wavelength of reflected light. This shift is directly proportional to force applied. The FBG sensors were housed in a protective sheath fashioned from a 0.025 in. flat coil, and attached to the chordae using polytetrafluoroethylene suture. The function of the force-sensing neochordae was validated in a three-dimensional (3D)-printed left heart simulator, which demonstrated that FBG sensors provide highly sensitive force measurements of mitral valve chordae at a temporal resolution of 1000 Hz. As ventricular pressures increased, such as in hypertension, chordae forces also increased. Overall, FBG sensors are a viable, durable, and high-fidelity sensing technology that can be effectively used to measure mitral valve chordae forces and overcome some limitations of other such technologies.

Echocardiographic examination of mitral valve abnormalities in the paediatric population: current practices

We reviewed the recent literature for echocardiographic assessment of mitral valve abnormalities in children. A literature search was performed within the National Library of Medicine using the keywords "mitral regurgitation and/or stenosis, children." The search was refined by adding the keywords "echocardiographic definition, classification, and evaluation." Thirty-one studies were finally included. Significant advances in echocardiographic imaging of mitral valve defects, mainly due to the implementation of three-dimensional technology, contribute to a better understanding of the underlying anatomy. However, heterogeneity between classification systems of mitral valve disease severity is a serious problem. For regurgitant lesions, there is only very limited evidence from small studies that support the adoption of quantitative/semi-quantitative indexes commonly employed in adults. Despite the lack of evidence base, qualitative evaluation of regurgitation severity is often employed. For stenotic lesions, no clear categorisation based on trans-valvular echocardiography-derived "gradients" has been consistently applied to define mild, moderate, or severe obstruction across different paediatric age ranges. Quantitative parameters such as valve area have also been poorly validated in children. Adult recommendations are frequently applied without validation for the paediatric age. In conclusion, significant advances in the anatomical evaluation of mitral valve diseases have been made, thanks to three-dimensional echocardiography; however, limitations remain in the quantitative/semi-quantitative estimation of disease severity, both with respect to valvular regurgitation and stenosis. Because adult echocardiographic recommendations should not be simply translated to the paediatric age, more specific paediatric guidelines and standards for the assessment of mitral valve diseases are needed.

Mitral valve repair for posterior leaflet prolapse: Long-term comparison of loop implantation vs resection

BACKGROUND

Resection (triangular or quadrangular) is considered the gold standard for the treatment of posterior leaflet prolapse and loop implantation a more recent alternative. We aimed to compare the long-term outcomes of triangular or quadrangular resection vs loop implantation.

METHODS

Single-centre, retrospective analysis of mitral valve (MV) surgeries conducted from January 2005 to December 2015. Propensity score matching was based on seven key baseline variables.

RESULTS

Data from 721 patients were analyzed; 358 patients received loop implantation and 363 patients underwent resection. Patients had a mean age of 62 years, 33.0% were female and 50.6% had hypertension. Propensity score matching resulted in a matched group of 263 patients who received loop implantation or underwent resection, respectively. Postoperatively, the patients' mitral insufficiency was reduced from grade III/IV to either zero or trace (45.8%) or I (49.8%) and New York Heart Association class reduced from 66.9% in class III/IV preoperatively to 8.3% with no significant differences between groups. Fewer patients receiving loops had procedure-related complications. Fewer patients in the loop implantation group required permanent pacemaker implantation at 30 days (8.4% vs 2.3%; P = .002). The 10-year survival for patients in the resection (88.0%) and loop implantation (89.3%) groups had a hazard ratio of 1.224 (95% confidence interval, 0.633-2.367).

CONCLUSION

Our study showed that both loop implantation and resection were associated with comparable long-term survival in patients with posterior leaflet prolapse. Loop implantation is associated with a significantly higher rate of a successful repair, a significantly lower rate of MV replacement after repair failure, fewer procedure-related complications and better 30-day at comparable long-term outcomes.

Case-matched Comparison of Cardiovascular Outcome in Loeys-Dietz Syndrome versus Marfan Syndrome

Background: Pathogenic variants in TGFBR1, TGFBR2 and SMAD3 genes cause Loeys-Dietz syndrome, and pathogenic variants in FBN1 cause Marfan syndrome. Despite their similar phenotypes, both syndromes may have different cardiovascular outcomes. Methods: Three expert centers performed a case-matched comparison of cardiovascular outcomes. The Loeys-Dietz group comprised 43 men and 40 women with a mean age of 34 ± 18 years. Twenty-six individuals had pathogenic variants in TGFBR1, 40 in TGFBR2, and 17 in SMAD3. For case-matched comparison we used 83 age and sex-frequency matched individuals with Marfan syndrome. Results: In Loeys-Dietz compared to Marfan syndrome, a patent ductus arteriosus (p = 0.014) was more prevalent, the craniofacial score was higher (p < 0.001), the systemic score lower (p < 0.001), and mitral valve prolapse less frequent (p = 0.003). Mean survival for Loeys-Dietz and Marfan syndrome was similar (75 ± 3 versus 73 ± 2 years; p = 0.811). Cardiovascular outcome was comparable between Loeys-Dietz and Marfan syndrome, including mean freedom from proximal aortic surgery (53 ± 4 versus 48 ± 3 years; p = 0.589), distal aortic repair (72 ± 3 versus 67 ± 2 years; p = 0.777), mitral valve surgery (75 ± 4 versus 65 ± 3 years; p = 0.108), and reintervention (20 ± 3 versus 14 ± 2 years; p = 0.112). In Loeys-Dietz syndrome, lower age at initial presentation predicted proximal aortic surgery (HR = 0.748; p < 0.001), where receiver operating characteristic analysis identified ≤33.5 years with increased risk. In addition, increased aortic sinus diameters (HR = 6.502; p = 0.001), and higher systemic score points at least marginally (HR = 1.175; p = 0.065) related to proximal aortic surgery in Loeys-Dietz syndrome. Conclusions: Cardiovascular outcome of Loeys-Dietz syndrome was comparable to Marfan syndrome, but the severity of systemic manifestations was a predictor of proximal aortic surgery.

Crossed Swords Sign: A 3-Dimensional Echocardiographic Appearance

Intraoperative evaluation of mitral regurgitation is a complex undertaking. Bileaflet prolapse/flail can result in divergent mitral regurgitation jets with a characteristic "crossed swords sign" appearance. We present a case of divergent mitral regurgitation jets that were detected intraoperatively and evaluated using 3-dimensional imaging. The accurate assessment of eccentric mitral regurgitation jets, especially bilateral eccentric mitral regurgitation jets, is challenging before surgical repair. Intraoperative 3-dimensional transesophageal echocardiography with and without color-flow Doppler can significantly improve the localization of the anatomical lesion.

Mitral Valve Prolapse and Sudden Cardiac Death: A Systematic Review

Background

The relationship between mitral valve prolapse (MVP) and sudden cardiac death (SCD) remains controversial. In this systematic review, we evaluate the relationship between isolated MVP and SCD to better define a potential high‐risk subtype. In addition, we determine whether premortem parameters could predict SCD in patients with MVP and the incidence of SCD in MVP.

Methods and Results

Electronic searches were conducted in PubMed and Embase for all English literature articles published between 1960 and 2018 regarding MVP and SCD or cardiac arrest. We also identified articles investigating predictors of ventricular arrhythmias or SCD and cohort studies reporting SCD outcomes in MVP. From 2180 citations, there were 79 articles describing 161 cases of MVP with SCD or cardiac arrest. The median age was 30 years and 69% of cases were female. Cardiac arrest occurred during situations of stress in 47% and was caused by ventricular fibrillation in 81%. Premature ventricular complexes on Holter monitoring (92%) were common. Most cases had bileaflet involvement (70%) with redundancy (99%) and nonsevere mitral regurgitation (83%). From 22 articles describing predictors for ventricular arrhythmias or SCD in MVP, leaflet redundancy was the only independent predictor of SCD. The incidence of SCD with MVP was estimated at 217 events per 100 000 person‐years.

Conclusions

Isolated MVP and SCD predominantly affects young females with redundant bileaflet prolapse, with cardiac arrest usually occurring as a result of ventricular arrhythmias. To better understand the complex relationship between MVP and SCD, standardized reporting of clinical, electrophysiological, and cardiac imaging parameters with longitudinal follow‐up is required.

Optically-guided instrument for transapical beating-heart delivery of artificial mitral chordae tendineae

OBJECTIVE

We sought to develop an instrument that would enable the delivery of artificial chordae tendineae (ACT) using optical visualization of the leaflet inside the beating heart.

METHODS

A delivery instrument was developed together with an ACT anchor system. The instrument incorporates an optically clear silicone grasping surface in which are embedded a camera and LED for direct leaflet visualization during localization, grasping, and chordal delivery. ACTs, comprised of T-shaped anchors and an expanded polytetrafluoroethylene chordae, were fabricated to enable testing in a porcine model. Ex vivo experiments were used to measure the anchor tear-out force from the mitral leaflets. In vivo experiments were performed in which the mitral leaflets were accessed transapically using only optical guidance and ACTs were deployed in the posterior and anterior leaflets (P2 and A2 segments).

RESULTS

In 5 porcine ex vivo experiments, the mean force required to tear the anchors from the leaflets was 3.8 ± 1.2 N. In 5 porcine in vivo nonsurvival procedures, 14 ACTs were successfully placed in the leaflets (9 in P2 and 5 in A2). ACT implantation took an average of 3.22 ± 0.83 minutes from entry to exit through the apex.

CONCLUSIONS

Optical visualization of the mitral leaflet during chordal placement is feasible and provides direct feedback to the operator throughout the deployment sequence. This enables visual confirmation of the targeted leaflet location, distance from the free edge, and successful deployment of the chordal anchor. Further studies are needed to refine and assess the device for clinical use.

Invasive pyogenic infection and infective endocarditis due to Streptococcus anginosus: A case report

RATIONALE

Streptococcus anginosus mostly colonizes the digestive and genitourinary system, including the oropharyngeal region. It commonly causes invasive pyogenic infection, but less likely causes infective endocarditis (IE).

PATIENT CONCERNS

An 18-year-old woman who had an underlying mitral valve prolapse without mitral regurgitation presented to our hospital with low-grade fever, left leg weakness, and left abdominal pain. She was diagnosed with brain infarction and microabscess as well as IE. The patient totally recovered after the 6-week course of intravenous antibiotics.

DIAGNOSIS

Brain magnetic resonance imaging revealed brain infarction and microabscess. Abdominal computed tomography revealed splenic and left renal infarction. Three sets of blood culture were positive for S anginosus. Transthoracic echocardiogram identified mitral valve prolapse with moderate eccentric mitral valve regurgitation, and a 0.3 × 0.6-cm vegetation was found on the left mitral valve. All of these results meet the modified Duke criteria.

INTERVENTIONS

The abdominal pain and left leg weakness were improving after 2 weeks of intravenous antibiotics treatment. No neurological sequelae were noted after completing the 6-week course of medical treatment.

OUTCOMES

The patient was successfully treated and discharged after completing the 6-week intravenous antibiotics treatment.

LESSONS

IE should be considered in young patients with native valve disease who have prolonged fever. Though S anginosus commonly causes invasive pyogenic infection, patients with native valve disease should be checked for IE.

Mitral Valve Prolapse, Ventricular Arrhythmias, and Sudden Death

Despite a 2% to 3% prevalence of echocardiographically defined mitral valve prolapse (MVP) in the general population, the actual burden, risk stratification, and treatment of the so-called arrhythmic MVP are unknown. The clinical profile is characterized by a patient, usually female, with mostly bileaflet myxomatous disease, mid-systolic click, repolarization abnormalities in the inferior leads, and complex ventricular arrhythmias with polymorphic/right bundle branch block morphology, without significant regurgitation. Among the various pathophysiologic mechanisms of electrical instability, left ventricular fibrosis in the papillary muscles and inferobasal wall, mitral annulus disjunction, and systolic curling have been recently described by pathological and cardiac magnetic resonance studies in sudden death victims and patients with arrhythmic MVP. In addition, premature ventricular beats arising from the Purkinje tissue as ventricular fibrillation triggers have been documented by electrophysiologic studies in MVP patients with aborted sudden death.

The genesis of malignant ventricular arrhythmias in MVP probably recognizes the combination of the substrate (regional myocardial hypertrophy and fibrosis, Purkinje fibers) and the trigger (mechanical stretch) eliciting premature ventricular beats because of a primary morphofunctional abnormality of the mitral valve annulus.

The main clinical challenge is how to identify patients with arrhythmic MVP (which imaging technique and in which patient) and how to treat them to prevent sudden death. Thus, there is a necessity for prospective multicenter studies focusing on the prognostic role of cardiac magnetic resonance and electrophysiologic studies and on the therapeutic efficacy of targeted catheter ablation and mitral valve surgery in reducing the risk of life-threatening arrhythmias, as well as the role of implantable cardioverter defibrillators for primary prevention.

Analysis of mitral valve regurgitation by computational fluid dynamics

The clinical syndrome of mitral insufficiency is a common consequence of mitral valve (MV) prolapse, when the MV leaflets do not seal the closed orifice and blood regurgitates back to the atrium during ventricular contraction. There are different types of MV prolapse that may influence the degree of regurgitation also in relation to the left ventricle (LV) geometry. This study aims to provide some insight into the fluid dynamics of MV insufficiency in view of improving the different measurements available in the clinical setting. The analysis is performed by a computational fluid dynamics model coupled with an asymptotic model of the MV motion. The computational fluid dynamics solution uses the immersed boundary method that is efficiently integrated with clinical imaging technologies. Healthy and dilated LVs obtained by multislice cardiac MRI are combined with simplified models of healthy and pathological MVs deduced from computed tomography and 4D-transesophageal echocardiography. The results demonstrated the properties of false regurgitation, blood that did not cross the open MV orifice and returns into the atrium during the backward motion of the MV leaflets, whose entity should be accounted when evaluating small regurgitation. The regurgitating volume is found to be proportional to the effective orifice area, with the limited dependence of the LV geometry and type of prolapse. These affect the percentage of old blood returning to the atrium which may be associated with thrombogenic risk.

Mechanical strain induces a pro-fibrotic phenotype in human mitral valvular interstitial cells through RhoC/ROCK/MRTF-A and Erk1/2 signaling pathways

The mitral valve is a complex multilayered structure populated by fibroblast-like cells, valvular interstitial cells (VIC) which are embedded in an extracellular matrix (ECM) scaffold and are submitted to the mechanical deformations affecting valve at each heartbeat, for an average of 40 million times per year. Myxomatous mitral valve (MMV) is the most frequent heart valve disease characterized by disruption of several valvular structures due to alterations of their ECM preventing the complete closure of the valve resulting in symptoms of prolapse and regurgitation. VIC and their ECM exhibit reciprocal dynamic processes between the mechanical signals issued from the ECM and the modulation of VIC phenotype responsible for ECM homeostasis of the valve. Abnormal perception and responsiveness of VIC to mechanical stress may induce an inappropriate adaptative remodeling of the valve progressively leading to MMV. To investigate the response of human VIC to mechanical strain and identify the molecular mechanisms of mechano-transduction in these cells, a cyclic equibiaxial elongation of 14% at the cardiac frequency of 1.16 Hz was applied to VIC by using a Flexercell-4000 T™ apparatus for increasing time (from 1 h to 8 h). We showed that cyclic stretch induces an early (1 h) and transient over-expression of TGFβ2 and αSMA. CTGF, a profibrotic growth factor promoting the synthesis of ECM components, was strongly induced after 1 and 2 h of stretching and still upregulated at 8 h. The mechanical stress-induced CTGF up-regulation was dependent on RhoC, but not RhoA, as demonstrated by siRNA-mediated silencing approaches, and further supported by evidencing RhoC activation upon cell stretching and suppression of cell response by pharmacological inhibition of the effector ROCK1/2. It was also dependent on the MEK/Erk1/2 pathway which was activated by mechanical stress independently of RhoC and ROCK. Finally, mechanical stretching induced the nuclear translocation of myocardin related transcription factor-A (MRTF-A) which forms a transcriptional complex with SRF to promote the expression of target genes, notably CTGF. Treatment of stretched cultures with inhibitors of the identified pathways (ROCK1/2, MEK/Erk1/2, MRTF-A translocation) blocked CTGF overexpression and abrogated the increased MRTF-A nuclear translocation. CTGF is up-regulated in many pathological processes involving mechanically challenged organs, promotes ECM accumulation and is considered as a hallmark of fibrotic diseases. Pharmacological targeting of MRTF-A by newly developed inhibitors may represent a relevant therapy for MMV.

Sudden Cardiac Deaths in Adults with Congenital Heart Disease with Structural Abnormalities: A Retrospective Review of Cases in the Cook County Medical Examiner's Office

Sudden cardiac death is a significant cause of mortality in adults with congenital heart disease (CHD). The Cook County Medical Examiner's Office database was queried for cases of CHD as a cause of death in the period between July 2008 and April 2019. Twenty-two cases were identified, including 11 decedents with simple defects and 10 decedents with complex defects. All of the subjects were in apparent good health at the time of death. In the absence of other obvious causes of death, simple defects were considered cases of sudden cardiac death. Significant cardiac morphological changes were common in complex defects. While 16 cases had known, diagnosed/treated CHD, 5 cases had no diagnosis prior to autopsy. In these cases, the ability to recognize CHD (sometimes subtle) helped in determining the causes of death. Therefore, forensic pathologists must be able to properly recognize various forms of CHD and request consultations, when needed.

Burden of Valvular Heart Diseases in Hispanic/Latino Individuals in the United States: The Echocardiographic Study of Latinos

OBJECTIVE

To explore the burden and clinical correlates of valvular heart disease in Hispanics/Latinos in the United States.

PATIENTS AND METHODS

A total of 1818 individuals from the population-based study of Latinos/Hispanics from 4 US metropolitan areas (Bronx, New York; Chicago, Illinois; San Diego, California; and Miami, Florida) underwent a comprehensive clinical and echocardiographic examination from October 1, 2011, through June 24, 2014. Logistic regression analysis was used to examine the associations of clinical and sociodemographic variables with valvular lesions.

RESULTS

The mean age was 55.2±0.2 years; 57.4% were female. The prevalence of any valvular heart disease (AVHD) was 3.1%, with no considerable differences across sex, and a higher prevalence with increasing age. The proportion of US-born vs foreign-born individuals was similar in those with vs without AVHD (P=.31). The weighted prevalence of AVHD was highest in Central Americans (8.4%) and lowest in Mexicans (1.2%). Regurgitant lesions of moderate or greater severity were present in 2.4% of the population and stenotic lesions of moderate or greater severity in 0.2%. Compared with those without AVHD, individuals with AVHD were more likely to have health insurance coverage (59.6% vs 79.2%; P=.007) but similar income (P=.06) and educational status (P=.46). Univariate regression models revealed that regurgitant lesions were associated with lower body mass index whereas stenotic lesions were associated with higher body mass index.

CONCLUSION

Our data provide the first population-based estimates of the prevalence of valvular heart disease in Hispanic/Latinos. Valvular heart disease is fairly common in the Hispanic/Latino population and may constitute an important public health problem.

Utilization of echocardiography in Ehlers-Danlos syndrome

OBJECTIVES

This study assessed the frequency and utility of echocardiographic examination in patients with all forms of Ehlers-Danlos syndrome and sought to identify clinical variables associated with an abnormal echocardiogram.

DESIGN/SETTING

This was a retrospective study of all patients carrying a diagnosis of Ehlers-Danlos syndrome of any type who were evaluated by a pediatrician or pediatric subspecialist at a single tertiary medical center with an affiliated children's hospital during the period January 2013 to December 2018.

PATIENTS

Chart review was performed on all patients carrying a diagnosis of Ehlers-Danlos syndrome in the electronic medical record.

OUTCOME MEASURES

Data from genetics examination, cardiovascular examination where applicable, genetic test results when available, and echocardiography were recorded.

RESULTS

Of 262 patients identified, echocardiography and cardiac evaluation were common occurring in 90% and 50% of patients with any form of Ehlers-Danlos syndrome. Cardiovascular complications occurred in 50% of patients with vascular Ehlers-Danlos syndrome but echocardiography was normal in all. Aortic dilation was common in classic Ehlers-Danlos syndrome but absent in hypermobile Ehlers-Danlos syndrome. Mitral valve prolapse and bicuspid aortic valve occurred at the same incidence as the general population. Cardiac symptoms were present in 12% but did not correlate with abnormal cardiac structure. Presentation with symptoms of musculoskeletal pain was inversely related to the presence of cardiac pathology.

CONCLUSIONS

In light of the absence of cardiac pathology in patients with hypermobile Ehlers-Danlos syndrome, routine cardiac evaluation and echocardiography are not required for patients with hypermobile Ehlers-Danlos syndrome.

Use of Contemporary Imaging Techniques for Electrophysiological and Device Implantation Procedures

Recent technological advances in cardiac imaging allow the visualization of anatomic details up to millimeter size in 3-dimensional format. Thus, it is not surprising that electrophysiologists increasingly rely upon cardiac imaging for the diagnosis, treatment, and subsequent management of patients affected by various arrhythmic disorders. Cardiac imaging methods reviewed in the present work involve: 1) the prediction of arrhythmic risk for sudden cardiac death in patients with heart disease; 2) catheter ablation of atrial fibrillation or ventricular tachycardia; and 3) cardiac resynchronization therapy. Future integration of diagnostic and interventional cardiac imaging will further increase the effectiveness of cardiac electrophysiological procedures and will help in delivering patient-specific therapies with ablation and cardiac implantable electronic devices.

Type 1 cluster of differentiation 36 deficiency-related cardiomyopathy accelerates heart failure with co-existing mitral valve prolapse: a case report

Background

Free fatty acid is a major energy source in the healthy heart and cluster of differentiation 36 (CD36) partially regulates the rate of myocardial fatty acid uptake. Here, we report a case of CD36 deficiency-related cardiomyopathy with a unique pathophysiology. Heart failure was accelerated by co-existing mitral valve prolapse (MVP) without a distinct phenotype of hypertrophic or dilated cardiomyopathy.

Case summary

A middle-aged man was aware of dyspnoea and hospitalized for heart failure with MVP. Cluster of differentiation 36 deficiency was found based on the absence of myocardial ¹²³l-15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid (BMIPP) uptake by myocardial scintigraphy. Type I CD36 deficiency was further diagnosed by the lack of CD36 in both platelets and monocytes by flow cytometry. Left ventricular muscle was obtained intraoperatively, and a histological examination reflected compensative hypertrophy of cardiomyocytes with myofibrillar loss and reactive fibrosis. The microvascular structure around the cardiomyocytes was highlighted by immunohistochemical staining for CD31, while CD36 expression was absent. He had an operation of mitral valve replacement and improved heart failure.

Discussion

Cluster of differentiation 36 deficiency potentially mediates various pathological conditions in the heart. Incidental CD36 deficiency-related cardiomyopathy may accelerate heart failure in the presence of co-existing heart diseases. BMIPP scintigraphy might be helpful for predicting CD36 deficiency.

Application of trans-thoracic echocardiography and coronary CT angiography to diagnose mitral valve prolapse

Objective

At present, multi-detector cardiac CT has been widely applied in the detection of heart valve morphology and function. This study aims to compare the coronary CT angiography and trans-thoracic echocardiography for patients with mitral valve prolapse.

Methods

CT angiography and trans-thoracic echocardiography were adopted to detect the movement range and thickness of valvula bicuspidalis. The ultrasonic parameters of CT angiography were considered as standard reference value.

Results

Receiver operating characteristic (ROC) curve showed that the area of mitral valve motion amplitude under ROC curve was 95% detected by CT angiography with statistical significance (P < 0.001). Based on the intercept point on the ROC curve, the sensitivity and accuracy of mitral valve amplitude detected by CT angiography was 69.2 and 95.6%, the false positive and false negative rate was 5.2 and 32.4%, the predicted value of positive and negative was 92.9 and 76.9% and the consistency rate of motion range and leaf thickness detected by CT angiography was 83.3 and 47.5%. Trans-thoracic echocardiography showed that the thickness and motion range of mitral leaflet was (1.95 ± 0.22) mm and (1.5 ± 2.28) mm. The thickness and motion range of mitral leaflet that detected by CT was (2.00 ± 0.54) mm and (3.76 ± 2.1) mm.

Conclusion

The accuracy and reliability of CT angiography for patients with mitral valve prolapse are higher than those of trans-thoracic echocardiography.

Endothelial Dysfunction in Patients with Severe Mitral Regurgitation

Mitral valve prolapse (MVP) is the most common cause of severe mitral regurgitation. It has been reported that MVP patients—candidates for mitral valve repair (MVRep)—showed an alteration in the antioxidant defense systems as well as in the L-arginine metabolic pathway. In this study, we investigate if oxidative stress and endothelial dysfunction are an MVP consequence or driving factors. Forty-five patients undergoing MVRep were evaluated before and 6 months post surgery and compared to 29 controls. Oxidized (GSSG) and reduced (GSH) forms of glutathione, and L-arginine metabolic pathway were analyzed using liquid chromatography-tandem mass spectrometry methods while osteoprotegerin (OPG) through the ELISA kit and circulating endothelial microparticles (EMP) by flow cytometry. Six-month post surgery, in MVP patients, the GSSG/GSH ratio decreased while symmetric and asymmetric dimethylarginines levels remained comparable to the baseline. Conversely, OPG levels significantly increased when compared to their baseline. Finally, pre-MVRep EMP levels were significantly higher in patients than in controls and did not change post surgery. Overall, these results highlight that MVRep completely restores the increased oxidative stress levels, as evidenced in MVP patients. Conversely, no amelioration of endothelial dysfunction was evidenced after surgery. Thus, therapies aimed to restore a proper endothelial function before and after surgical repair could benefit MVP patients.

A Novel Truncating Variant in FLNC-Encoded Filamin C May Serve as a Proarrhythmic Genetic Substrate for Arrhythmogenic Bileaflet Mitral Valve Prolapse Syndrome

A 51-year-old man with a long-standing history of bileaflet mitral valve prolapse accompanied by mitral annular disjunction and mild mitral regurgitation presented for evaluation of increasingly frequent palpitations. Ambulatory Holter monitoring, cardiac magnetic resonance imaging, serial transthoracic echocardiography, and diagnostic electrophysiology studies were consistent with a diagnosis of arrhythmogenic bileaflet mitral valve prolapse syndrome. Because of the presence of a similar phenotype in the proband's mother, brother, and maternal aunt, research-based whole exome sequencing was pursued and a novel truncating variant (p.Trp34*-FLNC) in the cardiomyopathy-causative FLNC-encoded filamin C unearthed that cosegregated with disease. Unexpectedly, these observations provide the first evidence that a heritable proarrhythmic genetic substrate (ie, FLNC haploinsufficiency-mediated weakening of cell-cell adhesion) may underlie, at least in part, some cases of arrhythmogenic mitral valve prolapse syndrome.

Genome-Wide Association Study-Driven Gene-Set Analyses, Genetic, and Functional Follow-Up Suggest GLIS1 as a Susceptibility Gene for Mitral Valve Prolapse

Background Mitral valve prolapse (MVP) is a common heart valve disease, the most frequent indication for valve repair or replacement. MVP is characterized by excess extracellular matrix secretion and cellular disorganization, which leads to bulky valves that are unable to coapt correctly during ventricular systole resulting in mitral regurgitation, and it is associated with sudden cardiac death. Here we aim to characterize globally the biological mechanisms underlying genetic susceptibility to MVP to better characterize its triggering mechanisms. Methods We applied i-GSEA4GWAS and DEPICT, two pathway enrichment tools to MVP genome-wide association studies. We followed-up the association with MVP in an independent dataset of cases and controls. This research was conducted using the UK Biobank Resource. Immunohistochemistry staining for Glis1 (GLIS family zinc finger 1) was conducted in developing heart of mice. Knockdown of Glis1 using morpholinos was performed in zebrafish animals 72 hours postfertilization. Results We show that genes at risk loci are involved in biological functions relevant to actin filament organization, cytoskeleton biology, and cardiac development. The enrichment for positive regulation of transcription, cell proliferation, and migration motivated the follow-up of GLIS1, a transcription factor from the Krüppel-like zinc finger family. In combination with previously available data, we now report a genome-wide significant association with MVP (odds ratio, 1.20; P=4.36×10-10), indicating that Glis1 is expressed during embryonic development predominantly in nuclei of endothelial and interstitial cells of mitral valves in mouse. We also show that Glis1 knockdown causes atrioventricular regurgitation in developing hearts in zebrafish. Conclusions Our findings define globally molecular and cellular mechanisms underlying common genetic susceptibility to MVP and implicate established and unprecedented mechanisms. Through the GLIS1 association and function, we point at regulatory functions during cardiac development as common mechanisms to mitral valve degeneration.

Increased levels of sST2 in patients with mitral annulus disjunction and ventricular arrhythmias

Objective

Displacement of the mitral valve, mitral annulus disjunction (MAD), is described as a possible aetiology of sudden cardiac death. Stress-induced fibrosis in the mitral valve apparatus has been suggested as the underlying mechanism. We aimed to explore the association between stretch-related and fibrosis-related biomarkers and ventricular arrhythmias in MAD. We hypothesised that soluble suppression of tumourigenicity-2 (sST2) and transforming growth factor-β1 (TGFβ1) are markers of ventricular arrhythmias in patients with MAD.

Methods

We included patients with ≥1 mm MAD on cardiac MRI. We assessed left ventricular ejection fraction (LVEF) and fibrosis by late gadolinium enhancement (LGE). The occurrence of ventricular arrhythmia, defined as aborted cardiac arrest, sustained or non-sustained ventricular tachycardia, was retrospectively assessed. We assessed circulating sST2 and TGFβ1 levels.

Results

We included 72 patients with MAD, of which 22 (31%) had ventricular arrhythmias. Patients with ventricular arrhythmias had lower LVEF (60 % (±6) vs 63% (±6), p = 0.04), more frequently papillary muscle fibrosis (14 (64%) vs 10 (20%), p < 0.001) and higher sST2 levels (31.6 ± 10.1 ng/mL vs 25.3 ± 9.2 ng/mL, p = 0.01) compared with those without, while TGFβ1 levels did not differ (p = 0.29). Combining sST2 level, LVEF and papillary muscle fibrosis optimally detected individuals with arrhythmia (area under the curve 0.82, 95% CI 0.73 to 0.92) and improved the risk model (p < 0.05) compared with single parameters.

Conclusion

Circulating sST2 levels were higher in patients with MAD and ventricular arrhythmias compared with arrhythmia-free patients. Combining sST2, LVEF and LGE assessment improved risk stratification in patients with MAD.

Predictive Factors for Progression of Mitral Regurgitation in Asymptomatic Patients With Mitral Valve Prolapse

Risk factors predicting progression from low grade to severe mitral regurgitation (MR), which is a guideline criterion for surgical intervention, remain unknown. We hypothesized that abnormalities of cardiac structure and function may predict progression in MR severity. We followed 82 asymptomatic mitral valve prolapse (MVP) patients (65 ± 12 years, 51% men) with mild or moderate MR (36 mild, 46 moderate, mean LVEF: 62%), without significant co-morbidities. We examined clinical findings and 13 echo measurements. The primary end point was progression to severe MR. In a mean follow-up period of 4.5 ± 2.7 years, mortality and heart failure development were similar for mild and moderate MR. No mild MR patient progressed to severe, but 23 moderate MR patients (50.0%) progressed to severe with 9 patients (39.1%) who underwent surgery. No clinical variables were predictive for progression. Only mean mitral annulus diameter (apical 4 and 2 chamber) was predictive for progression to severe MR (hazards ratio 1.14, 95% confidence interval 1.03 to 1.26, p = 0.01). A cut-off annulus diameter of 39.6 mm had a good accuracy (area under the curve 0.78, sensitivity 100%, and specificity 63.8%) for progression to severe. In conclusion, over a 4.5-year period, 50% of asymptomatic MVP patients with moderate MR, but none with mild, progressed to severe MR. Only mitral annular dimension predicted progression of moderate to severe MR, and values >39.6 mm predicted progression accurately. Mitral annulus diameter may be of value in identifying asymptomatic MVP patients at risk of developing severe MR.

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.

Equine Acquired Valvular Disease

Degenerative myxomatous disease is common and is associated with aging. Poor prognostic indicators for equine aortic regurgitation specifically include ventricular ectopy, increased pulse pressure, and hyperkinetic pulses. Valvular prolapse is a functional abnormality diagnosed echocardiographically, about which knowledge is limited. A better understanding of its role in valvular regurgitation is needed. Infective endocarditis presents with fever and other systemic signs accompanying valvular regurgitation. The prognosis is poor, warranting aggressive therapy. Other forms of valvular disease occur rarely, but often presenting with severe regurgitation. Management of horses with valvular disease is focused on assessment of severity and regular clinical, echocardiographic, and electrocardiographic monitoring.

Management and outcomes in mitral valve prolapse with ventricular arrhythmias undergoing ablation and/or implantation of ICDs

BACKGROUND

While there is an association between isolated mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), the baseline characteristics and outcomes of patients with isolated MVP who experience ventricular arrhythmias (VAs) and then subsequently undergo catheter ablation and/or implantable cardioverter defibrillator (ICD) implantation are unknown.

METHODS

We performed a retrospective review of all patients at the Cleveland Clinic with isolated MVP between 1997 and 2016 who underwent VA catheter ablation or secondary prevention ICD implantation.

RESULTS

Of 617 screened patients, we identified 43 patients with isolated MVP and significant VA who underwent ICD placement (n = 13, 30%) or catheter ablation (n = 30, 70%). Both leaflets were most commonly involved (n = 22, 52%) with posterior MVP being next most common (n = 15, 36%). The most common foci of VA origin was the left ventricular papillary muscle (n = 9, 27%). Ablation was successful in the majority of cases (n = 20, 65%). At a mean follow-up of 2.5 years, 11 patients (26%) had recurrent VT.

CONCLUSIONS

Patients with isolated MVP and VA were more likely to have bileaflet prolapse and at least moderate mitral regurgitation. VA originated more commonly from left-sided foci. While ablation was acutely successful in the majority of cases, there was still a moderate rate of VA recurrence. There is still more study needed on factors that will predict malignant VAs and management of these VAs in the MVP population.

Native aortic versus mitral valve infective endocarditis: a nationwide registry study

Background

Native aortic and mitral valve infective endocarditis (AVE and MVE, respectively) are usually grouped together as left-sided native valve infective endocarditis (LNVE), while the differences between AVE and MVE have not yet been properly investigated. We aimed to compare AVE and MVE in regard to patient characteristics, microbiology and determinants of survival.

Methods

We conducted a retrospective study using the Swedish national registry on infective endocarditis, which contains nationwide patient data. The study period was 2007‒2017, and included cases were patients who had either AVE or MVE.

Results

We included 649 AVE and 744 MVE episodes. Staphylococcus aureus was more often the causative pathogen in MVE (41% vs 31%, p<0.001), whereas enterococci were more often the causative pathogen in AVE (14% vs 7.4%, p<0.001). Perivalvular involvement occurred more frequently in AVE (8.5% vs 3.5%, p<0.001) and brain emboli more frequently in MVE (21% vs 13%, p<0.001). Surgery for IE was performed more often (35% vs 27%, p<0.001) and sooner after diagnosis (6.5 days vs 9 days, p=0.012) in AVE than in MVE. Several risk predictors differed between the two groups.

Conclusions

The microbiology seems to differ between AVE and MVE. The causative pathogen was not associated with mortality in AVE. The between-group differences regarding clinical presentation and predictors of survival indicate that it may be important to differentiate AVE from MVE in the treatment of LNVE.

Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse

OBJECTIVE

Bileaflet mitral valve prolapse (MVP) with either focal or diffuse myocardial fibrosis has been linked to ventricular arrhythmia and/or sudden cardiac arrest. Left ventricular (LV) mechanical dispersion by speckle-tracking echocardiography (STE) is a measure of heterogeneity of ventricular contraction previously associated with myocardial fibrosis. The aim of this study is to determine whether mechanical dispersion can identify MVP at higher arrhythmic risk.

METHODS

We identified 32 consecutive arrhythmic MVPs (A-MVP) with a history of complex ventricular ectopy on Holter/event monitor (n=23) or defibrillator placement (n=9) along with 27 MVPs without arrhythmic complications (NA-MVP) and 39 controls. STE was performed to calculate global longitudinal strain (GLS) as the average peak longitudinal strain from an 18-segment LV model and mechanical dispersion as the SD of the time to peak strain of each segment.

RESULTS

MVPs had significantly higher mechanical dispersion compared with controls (52 vs 42 ms, p=0.005) despite similar LV ejection fraction (62% vs 63%, p=0.42) and GLS (-19.7 vs -21, p=0.045). A-MVP and NA-MVP had similar demographics, LV ejection fraction and GLS (all p>0.05). A-MVP had more bileaflet prolapse (69% vs 44%, p=0.031) with a similar degree of mitral regurgitation (mostly trace or mild in both groups) (p>0.05). A-MVP exhibited greater mechanical dispersion when compared with NA-MVP (59 vs 43 ms, p=0.0002). Mechanical dispersion was the only significant predictor of arrhythmic risk on multivariate analysis (OR 1.1, 95% CI 1.02 to 1.11, p=0.006).

CONCLUSIONS

STE-derived mechanical dispersion may help identify MVP patients at higher arrhythmic risk.

Characteristics of mitral valve leaflet length in patients with pectus excavatum: A single center cross-sectional study

The mitral valve morphology in patients with pectus excavatum (PE) has not been fully investigated. Thirty-five patients with PE, 46 normal controls, and patients with hypertrophic cardiomyopathy (HCM) who underwent 2 leaflet length measurements of Carpentier classification P2 and A2 using a transthoracic echocardiography were retrospectively investigated. The coaptation lengths and depths, papillary muscle tethering length, and mitral annular diameters were also measured. The P2 and A2 lengths were separately compared between 2 groups: older than 16 years and 16 years or younger. Furthermore, the correlations between actual P2 or A2 lengths and Haller computed tomography index, an index of chest deformity, were investigated in patients with PE exclusively. Among subjects older than 16 years, patients with PE had significantly shorter P2, longer A2, shorter copatation depth, and longer papillary muscle tethering length compared with normal controls. Similarly, patients with PE had significantly shorter P2 and shorter coaptation depth even compared with patients with HCM, while no significant difference was found in A2 length and papillary muscle tethering length. The same tendency was noted between 4 normal controls and 7 age- and sex-matched patients with PE ≤ 16 years old. No significant difference regarding A2/P2 ratio was found between patients with PE older and younger than 16 years. No significant correlation between the Haller computed tomography index and actual mitral leaflet lengths in patients with PE older than 16 years was noted; the same was observed for A2/P2 in all patients with PE. In conclusion, the characteristic features of the shorter posterior mitral leaflet, the longer anterior mitral leaflet, the shorter coaptation depth, and the longer papillary muscle tethering length in patients with PE was demonstrated. This finding might provide a clue regarding the etiology of mitral valve prolapse in PE at its possible earliest form.

Overview of mitral regurgitation in Europe: results from the European Registry of mitral regurgitation (EuMiClip)

Aims

To determine the prevalence of mitral regurgitation (MR) in a large cohort of consecutive patients undergoing clinically indicated echocardiography and to examine the distribution of primary and secondary MR.

Methods and results

All patients undergoing an echocardiographic study in 19 European centres within a 3-month period were prospectively included. MR assessment was performed as recommended by the European Association of Cardiovascular Imaging (EACVI). MR was classified according to mechanism as primary or secondary and aetiologies were reported. A total of 63 463 consecutive echocardiographic studies were reviewed. Any degree of MR was described in 15 501 patients. Concomitant valve disease of at least moderate grade was present in 28.5% of patients, being tricuspid regurgitation the most prevalent. In the subgroup of moderate and severe MR (n = 3309), 55% of patients had primary MR and 30% secondary MR. Both mechanisms were described in 14% of the studies. According to Carpentier's classification, 26.7% of MR were classified as I, 19.9% of MR as II, 22.4% of MR as IIIa, and 31.1% of MR as IIIb.

Conclusion

To date, this is the largest echocardiography-based study to analyse the prevalence and aetiology distribution of MR in Europe. The burden of secondary MR was higher than previously described, representing 30% of patients with significant MR. In our environment, degenerative disease is the most common aetiology of primary MR (60%), whereas ischaemic is the most common aetiology of secondary MR (51%). Up to 70% of patients with severe primary MR may have a Class I indication for surgery. However, the optimal therapeutic approach for secondary MR remains uncertain.

Trends in mitral valve prolapse: a tertiary care center experience in Jeddah, Saudi Arabia

Background

Mitral valve prolapse (MVP) is the most common cardiac valvular abnormality in developed countries and it is associated with considerable morbidity and mortality.

Aim of work

To study the clinical presentations, risk factors, and echocardiographic features of patients with MVP in Jeddah, Saudi Arabia.

Materials and methods

A retrospective chart review study was conducted in King Abdulaziz teaching hospital in Jeddah, Saudi Arabia, from 2007 to 2017. All patients with MVP who were admitted at the hospital during this time period were recruited to this study, and demographic, clinical, and echocardiographic variables were analyzed using IBM SPSS.

Results

Ninety-seven patients were recruited to this study, with a mean age of 43.82±16.16 years. Females constituted 67%. The body mass index (BMI) was 24.9±6.3 kg/m². Hypertension, diabetes, and dyslipidemia occurred in 19.6%, 5.2%, and 5.2% of patients, respectively. A single patient had Marfan syndrome. Chest pain, palpitations, and dyspnea were the presenting symptoms in 23.7%, 11.3%, and 9.3% of patients, respectively, with elderly individuals presenting disproportionally (93.3%) with palpitations. Fifty-five percent of patients had an anterior leaflet prolapse. The presence of posterior leaflet prolapse and severe mitral regurgitation (MR) was significantly associated with left atrial and left ventricular dilatation (P<0.05 and P<0.001, respectively).

Conclusion

MVP is more prevalent in women and middle-aged individuals with normal BMIs in this population. The most common clinical presentations were chest pain, palpitations, and dyspnea, which did not differ significantly with age or gender. The anterior leaflet was the most commonly prolapsed in the studied patients and presented with mild MR. Posterior leaflet MVP, while of low prevalence, was associated with severe MR and poor left ventricular function.