Floppy mitral valve/mitral valve prolapse: A complex entity with multiple genotypes and phenotypes

The relationship between mitral valve prolapse and thoracic skeletal abnormalities in clinical practice: a systematic review

BACKGROUND

Literature data suggest high inter-study variability in mitral valve prolapse (MVP) prevalence among individuals with thoracic skeletal abnormalities (TSA). This systematic review aimed at estimating the overall prevalence of MVP in individuals with the most common TSA, including not only the oldest studies (before the year 2000) but also the most recent ones (after the year 2000).

METHODS

PubMed and EMBASE databases were systematically reviewed in November 2023. Studies assessing the relationship between MVP and TSA and estimating the MVP prevalence in pectus excavatum (PE), pectus carinatum (PC), scoliosis, straight back syndrome (SBS) and Marfan syndrome (MS) were included. There was no limitation on time periods.

RESULTS

Twenty-five studies with a total of 2800 patients (27.9 ± 13.9 years, 48.2% females) were analyzed. The highest prevalence of MVP was observed among MS patients (47.3%), while the lowest was detected in PC individuals (23%). Prevalence of MVP was similar among PE (30.8%), scoliosis (26.3%) and SBS (25.5%) patients. When dividing the studies on the basis of temporal period, the average MVP prevalence was approximately two-fold higher in all studies conducted before the year 2000 in comparison with the most recent ones, regardless of TSA type. This discrepancy might be primarily ascribed to relevant differences in the echocardiographic criteria employed for MVP diagnosis before (less specific) and after (more specific) the year 2000, respectively.

CONCLUSIONS

The estimated MVP prevalence in TSA individuals is significantly higher than that observed in the general population. Individuals with TSA should be screened for MVP presence on transthoracic echocardiography.

Effects of Mitral Valve Surgery on Ventricular Arrhythmia in Mitral Valve Prolapse Patients: Five-Year Eollow-up

Aim      To evaluate the effect of mitral valve (MV) repair and replacement on the incidence of ventricular arrhythmias (VA) and to identify risk factors for the persistence of VA in patients with MV prolapse and severe mitral regurgitation (MR) during a mid-term follow-up.Material and methods  A single-site observational, prospective study successively enrolled 30 patients (mean age, 55.2±9.9 years, 60% men) who underwent MV repair or replacement for severe MR due to MV prolapse or chordal avulsion. Transthoracic echocardiography and Holter monitoring were performed in all patients before and annually after surgery. A pathomorphological study of MV fragments excised during surgery was performed.Results During the five-year follow-up period (144 person-years), one case of sudden cardiac death outside a health care facility was recorded. MR severity progressed in three patients after MV repair. The total number of all VAs decreased during the follow-up period, with a significant decrease in the number of paroxysms of unstable ventricular tachycardia during the first two years after surgery. The presence of VA in the postoperative period was correlated with the severity of postoperative left ventricular (LV) remodeling: end-diastolic volume (EDV) (rs=0.69; p=0.005), LV ejection fraction (EF) (rs = -0.55; p=0.004) and severity of MV myxomatous alterations according to histological study data (rτ=0.58; p=0.045). The beta-blocker treatment did not influence the VA frequency and severity (rs= -0.18; p=0.69). According to a univariate regression analysis only EDV (p = 0.001), LVEF <50% (p = 0.003), and myxomatous MV degeneration (p = 0.02) were risk factors for persistent ventricular tachycardia in the postoperative period.Conclusion      Surgical intervention on MV in patients with MV prolapse and severe MR decreased the number of cases of malignant VAs and was correlated with the postoperative changes in LV volume and function, as well as the severity of MV myxomatous alterations.

Subvalvular techniques enhanced with endoscopic robotic mitral valve repair

Objective

Totally endoscopic intracardiac robotic surgery is generally limited to uncomplicated mitral valve surgery. With experience, our team has developed a more aggressive approach to robotic cardiac surgery that allows for repair of a broad spectrum of mitral valve pathologies. We report complex subvalvular procedural advancements associated with this approach secondary to enhanced team experience and capabilities.

Methods

All robotic mitral procedures performed by a 2-surgeon team in a quaternary care medical center from July 2011 to May 2022 were reviewed. Natural language-processing techniques were used to analyze operative reports for subvalvular repair techniques. Complex subvalvular techniques included papillary muscle repositioning, division of secondary anterior leaflet chordae, septal myomectomy, division of aberrant left ventricular muscle band attachments, and left ventricular patch reconstruction. The surgical experience was divided into 2 periods: early robotic experience (pre-2018) versus late (2018 onwards). Baseline demographics, outcomes, and subvalvular techniques were analyzed and compared.

Results

A total of 1287 intracardiac robotic operations were performed by a 2-surgeon team. Thirty-day mortality was 0.6% (8/1287). Mitral valve repair was performed in 1024 patients. The mean age was 61 years (range, 18-90 years), and 15% were >75 years old; 29 patients (2.8%) had previously undergone cardiac surgery. There was a significant increase with experience in the application of advanced subvalvular techniques between the early versus late period (52.3% [268/512] vs 74.2% [380/512] (P < .001)).

Conclusions

An experienced 2-surgeon team can perform progressively more complex robotic subvalvular repair techniques. These subvalvular techniques are a surrogate for team proficiency and capabilities.

Arrhythmic Mitral Valve Prolapse: A Comprehensive Review

Mitral valve prolapse (MVP) is a prevalent cardiac disorder that impacts approximately 2% to 3% of the overall population. While most patients experience a benign clinical course, there is evidence suggesting that a subgroup of MVP patients face an increased risk of sudden cardiac death (SCD). Although a conclusive causal link between MVP and SCD remains to be firmly established, various factors have been associated with arrhythmic mitral valve prolapse (AMVP). This study aims to provide a comprehensive review encompassing the historical background, epidemiology, pathology, clinical manifestations, electrocardiogram (ECG) findings, and treatment of AMVP patients. A key focus is on utilizing multimodal imaging techniques to accurately diagnose AMVP and to highlight the role of mitral annular disjunction (MAD) in AMVP.

Acute mitral regurgitation with and without acute heart failure

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

Mitral valve prolapse and physical performance in Asian military males: The CHIEF Heart study

The impact of mitral valve prolapse (MVP) and mitral regurgitation (MR) on physical performance has not been examined. Of 1,808 physically fit Asian military males, we compared the physical fitness between 62 subjects with MVP (MVP(+)) and 1,311 age- and anthropometrics-matched controls from the 1,746 participants without MVP (MVP(-)). MVP and MR grade were defined based on the American Society of Echocardiography criteria. Aerobic endurance capacity was evaluated by a 3000-m run and muscular endurance capacity was separately evaluated by 2-min sit-ups and 2-min push-ups. Analysis of covariance was used to determine the difference between groups. As compared to the MVP(-), the MVP(+) completed the 3000-m run test faster (839.2 ± 65.3 sec vs. 866.6 ± 86.8 sec, p = 0.019), but did fewer push-ups (41.3 ± 3.92 vs. 48.0 ± 10.1, p = 0.02) and similar sit-ups within 2 min. Of the MVP(+), those with any MR (trivial, mild or moderate) completed the 3000-m run test faster than those without MR (830.6 ± 61.7 sec vs. 877.2 ± 61.7 sec, p = 0.02). Our findings suggest that in physically active Asian military males, the MVP(+) may have greater aerobic endurance capacity but lower muscular endurance capacity than the MVP(-). The presence of MR may play a role for the MVP(+) to have greater aerobic endurance capacity.

Myocardial Fibrosis at Cardiac MRI Helps Predict Adverse Clinical Outcome in Patients with Mitral Valve Prolapse

Background Patients with mitral valve prolapse (MVP) may develop adverse outcomes even in the absence of mitral regurgitation or left ventricular (LV) dysfunction. Purpose To investigate the prognostic value of mitral annulus disjunction (MAD) and myocardial fibrosis at late gadolinium enhancement (LGE) cardiac MRI in patients with MVP without moderate-to-severe mitral regurgitation or LV dysfunction. Materials and Methods In this longitudinal retrospective study, 118 144 cardiac MRI studies were evaluated between October 2007 and June 2020 at 15 European tertiary medical centers. Follow-up was from the date of cardiac MRI examination to June 2020; the minimum and maximum follow-up intervals were 6 months and 156 months, respectively. Patients were excluded if at least one of the following conditions was present: cardiomyopathy, LV ejection fraction less than 40%, ischemic heart disease, congenital heart disease, inflammatory heart disease, moderate or worse mitral regurgitation, participation in competitive sport, or electrocardiogram suggestive of channelopathies. In the remainder, cardiac MRI studies were reanalyzed, and patients were included if they were aged 18 years or older, MVP was diagnosed at cardiac MRI, and clinical information and electrocardiogram monitoring were available within 3 months from cardiac MRI examination. The end point was a composite of adverse outcomes: sustained ventricular tachycardia (VT), sudden cardiac death (SCD), or unexplained syncope. Multivariable Cox regression analysis was performed. Results A total of 474 patients (mean age, 47 years ± 16 [SD]; 244 women) were included. Over a median follow-up of 3.3 years, 18 patients (4%) reached the study end point. LGE presence (hazard ratio, 4.2 [95% CI: 1.5, 11.9]; P = .006) and extent (hazard ratio, 1.2 per 1% increase [95% CI: 1.1, 1.4]; P = .006), but not MAD presence (P = .89), were associated with clinical outcome. LGE presence had incremental prognostic value over MVP severity and sustained VT and aborted SCD at baseline (area under the receiver operating characteristic curve, 0.70 vs 0.62; P = .03). Conclusion In contrast to mitral annulus disjunction, myocardial fibrosis determined according to late gadolinium enhancement at cardiac MRI was associated with adverse outcome in patients with mitral valve prolapse without moderate-to-severe mitral regurgitation or left ventricular dysfunction. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gerber in this issue.

Genome-wide analysis of RNA-binding proteins co-expression with alternative splicing events in mitral valve prolapse

Objectives

We investigated the role and molecular mechanisms of RNA-binding proteins (RBPs) and their regulated alternative splicing events (RASEs) in the pathogenesis of mitral valve prolapse (MVP).

Methods

For RNA extraction, we obtained peripheral blood mononuclear cells (PBMCs) from five patients with MVP, with or without chordae tendineae rupture, and five healthy individuals. High-throughput sequencing was used for RNA sequencing (RNA-seq). Differentially expressed genes (DEGs) analysis, alternative splicing (AS) analysis, functional enrichment analysis, co-expression of RBPs, and alternative splicing events (ASEs) analysis were conducted.

Results

The MVP patients exhibited 306 up-regulated genes and 198 down-regulated genes. All down- and up-regulated genes were enriched in both Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Furthermore, MVP was closely associated with the top 10 enriched terms and pathways. In MVP patients, 2,288 RASEs were found to be significantly different, and four suitable RASEs (CARD11 A3ss, RBM5 ES, NCF1 A5SS, and DAXX A3ss) were tested. We identified 13 RNA-binding proteins (RBPs) from the DEGs and screened out four RBPs (ZFP36, HSPA1A, TRIM21, and P2RX7). We selected four RASEs based on the co-expression analyses of RBPs and RASEs, including exon skipping (ES) of DEDD2, alternative 3' splice site (A3SS) of ETV6, mutually exclusive 3'UTRs (3pMXE) of TNFAIP8L2, and A3SS of HLA-B. Furthermore, the selected four RBPs and four RASEs were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and showed high consistency with RNA sequencing (RNA-seq).

Conclusion

Dysregulated RBPs and their associated RASEs may play regulatory roles in MVP development and may therefore be used as therapeutic targets in the future.

Complex sympathetic regulation in adolescent mitral valve prolapse

Mitral valve prolapse (MVP) belongs to cardiac disorders characterized by impaired closure of mitral leaflets. We studied adolescent group of patients with MVP suffering from symptomatology that cannot be explained by mitral regurgitation alone. Several studies suggested that symptoms can be explained by autonomic, in particular sympathetic-linked dysfunction. Thus, we assessed non-invasive sympathetic indices of blood pressure and heart rate variability and electrodermal activity (EDA). Fifty-three adolescents with MVP (age: 15.1+/-0.4 years) and 43 healthy age- and gender-matched adolescents (age: 14.9+/-0.4 years) were examined. Blood pressure, heart rate and EDA were continuously recorded during 6-min rest. Evaluated parameters were: low frequency band of systolic blood pressure variability, systolic, diastolic and mean blood pressure, mean RR interval, cardiac sympathetic indices: symbolic dynamics (0V%), left ventricular ejection time (LVET), pre-ejection period (PEP), and EDA. Our findings revealed significantly higher systolic, diastolic, and mean blood pressure values, shortened mean RR interval, increased 0V%, and shortened LVET in MVP patients vs. controls (p=0.028, p<0.001, p=0.002, p<0.001, p=0.050, p<0.001; respectively). Our study revealed enhanced cardiovascular sympathetic regulation in adolescent MVP patients. We suggest that evaluation of non-invasive sympathetic parameters could represent potential biomarkers for early diagnosis of cardiovascular complications associated with MVP already at adolescent age.

Totally endoscopic aortic valve replacement with concomitant trans-aortic mitral valve repair for mitral regurgitation

Background

Minimally invasive aortic valve procedures through a hemi-sternotomy or a right anterior mini-thoracotomy have gained popularity over the last several years. Totally endoscopic aortic valve replacement (TEAVR) is an innovative and a less invasive (incision-wise) surgical aortic valve replacement technique. The operative steps of TEAVR have been reported previously from our group. Mitral regurgitation (MR) frequently accompanies aortic valve disease that at times may also require repair. Totally endoscopic surgery in such cases has not been tested.

Presentation of the technique

We present a surgical technique for a totally endoscopic approach to aortic valve replacement and concomitant mitral valve repair for primary and secondary MR. An aortotomy incision was used avoiding an atriotomy, which results in an increase in cross-clamp (XC) and cardiopulmonary bypass (CPB) times that could be associated with higher mortality and morbidity. Neochords (artificial chordae tendineae) were used for primary MR and an edge-to-edge approach for secondary MR.

Conclusion

TEAVR and concomitant mitral valve repair can be performed successfully with reasonable XC and CPB times with excellent short-term results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01694-6.

Arrhythmic mitral valve prolapse: Diagnostic parameters for high-risk patients: A systematic review and meta-analysis

BACKGROUND

Although frequently considered a benign condition, new evidence has shown that mitral valve prolapse (MVP) is associated with complex ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Therefore, we conducted a systematic review and meta-analysis of the relevant studies to investigate the parameters that could identify MVP patients at higher risk of experiencing complex VAs.

METHOD

We performed a systematic literature search of PubMed for potential studies between January 2010 and January 2021. Our meta-analysis included studies comparing MVP patients with complex VAs (A-MVP) and those without (NA-MVP). We used the fixed-effects model to obtain the odds ratio (OR), risk ratio (RR), or mean difference (MD) and 95% confidence interval (CI) for each analyzed parameter.

RESULTS

Six studies with 848 individuals were included in the meta-analysis. As compared to the NA-MVP patients, A-MVP patients had a higher prevalence of inverted T-wave (OR: 2.73; 95% CI: 1.85-4.02; p < .00001) and longer QTc interval on the resting ECG (MD: 14.73; 95% CI: 9.39-20.08; p < .00001), longer anterior mitral leaflet length (MD: 2.67; 95% CI: 2.02-3.31; p < .00001), bi-leaflet prolapse (OR: 1.65; 95% CI: 1.22-2.24; p = .001), and mitral annulus disjunction (MAD) on echocardiogram (RR: 1.90; 95% CI: 1.50-2.40; p < .00001), and late gadolinium enhancement (LGE) on cardiac magnetic resonance (RR: 4.38; 95% CI: 1.77-10.86; p = .001).

CONCLUSION

Our comprehensive meta-analysis suggests that risk factors related to A-MVP are T-wave inversion, longer QTc interval, bi-leaflet prolapse, longer anterior mitral valve leaflet, MAD, and LGE.

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

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

Use of whole genome analysis to identify shared genomic variants across breeds in canine mitral valve disease

Familial mitral valve prolapse in human beings has been associated with several genetic variants; however, in most cases, a known variant has not been identified. Dogs also have a naturally occurring form of familial mitral valve disease (MMVD) with similarities to the human disease. A shared genetic background and clinical phenotype of this disease in some dog breeds has indicated that the disease may share a common genetic cause. We evaluated DNA from 50 affected dogs from five different dog breeds in a whole genome sequencing approach to identify shared variants across and within breeds that could be associated with MMVD. No single causative genetic mutation was found from the 50 dogs with MMVD. Ten variants were identified in 37/50 dogs around and within the MED13L gene. These variants were no longer associated with MMVD when evaluated with a larger cohort including both affected and unaffected dogs. No high/moderate impact variants were identified in 10/10 miniature poodles, one was identified in 10/10 Yorkshire Terriers and 10/10 dachshunds, respectively, 14 were identified in 10/10 Miniature schnauzers, and 19 in 10/10 CKCS. Only one of these could be associated with the cardiac valve (Chr12:36801705, COL12A1; CKCS) but when evaluated in an additional 100 affected CKCS the variant was only identified in 84/100 affected dogs, perhaps indicating genetic heterogeneity in this disease. Our findings indicate that development of MMVD in the dog may be related to a combination of genetic and environmental factors that impact specific molecular pathways rather than a single shared genetic variant across or within breeds.

The Mitral Annular Disjunction of Mitral Valve Prolapse: Presentation and Outcome

OBJECTIVES

The aim of this study was to assess in patients with mitral valve prolapse (MVP) mitral annular disjunction (MAD) prevalence, phenotypic characteristics, and long-term outcomes (clinical arrhythmic events and excess mortality).

BACKGROUND

Clinical knowledge regarding MAD of MVP remains limited and controversial, and its potential link with untoward outcomes is unsubstantiated.

METHODS

A cohort of 595 (278 women, mean age 61 ± 16 years) consecutive patients with isolated MVP, with comprehensive clinical, rhythmic, Doppler echocardiographic, and consistent MAD assessment, were examined. MAD prevalence, associated MVP phenotypes, and outcomes (survival, clinical arrhythmic events) starting at diagnostic echocardiography were analyzed. To balance important baseline differences, propensity scoring matching was conducted among patients with and those without MAD.

RESULTS

The presence of MAD was common (n = 186 [31%]) in patients with MVP, generally in younger patients, and was not random but was independently associated with severe myxomatous disease involving bileaflet MVP and marked leaflet redundancy (both P ≤ 0.0002). The presence of MAD was also independently associated with a larger left ventricle (P = 0.005). Age-matched cohort survival after MVP diagnosis was not worse with MAD (10-year survival 93% ± 2% for patients without MAD and 97% ± 1% for those with MAD; P = 0.40), even adjusted comprehensively for MVP characteristics (P = 0.80) and accounting for time-dependent mitral surgery (P = 0.60). During follow-up, 170 patients had clinical arrhythmic events (ventricular tachycardia, n = 159; arrhythmia ablation, n = 14; cardioverter-defibrillator implantation, n = 14; sudden cardiac death, n = 3). MAD was independently associated with higher risk for arrhythmic events (adjusted HR: 2.60; 95% CI: 1.87-3.62; P < 0.0001). The link between MAD and arrhythmic events persisted with time-dependent mitral surgery (adjusted HR: 2.54; 95% CI: 1.84-3.50; P < 0.0001), was strong under medical management (adjusted HR: 3.21; 95% CI: 2.03-5.06; P < 0.0001) but was weaker after mitral surgery (adjusted HR: 2.07; 95% CI: 1.24-3.43; P = 0.005).

CONCLUSIONS

This large cohort with MVP comprehensively characterized shows that MAD is frequent at MVP diagnosis and is strongly linked to advanced myxomatous degeneration. The presence of MAD was independently associated with long-term excess incidence of clinical arrhythmic events. However, within the first 10 years post-diagnosis, MAD was not linked to excess mortality, and although reassurance should be provided from the survival point of view, careful monitoring for arrhythmias is in order for MAD.

Tricuspid Annulus Disjunction: Novel Findings by Cardiac Magnetic Resonance in Patients With Mitral Annulus Disjunction

OBJECTIVES

This study aimed to assess whether patients with MAD also have disjunction of the tricuspid annulus.

BACKGROUND

Mitral annulus disjunction (MAD) is an abnormal atrial displacement of the mitral annulus. Whether the disjunction extends to the right side of the heart is not known.

METHODS

In a cohort of patients with MAD, we assessed the presence of tricuspid annulus disjunction (TAD) with the use of cardiac magnetic resonance. We explored the associations between TAD and MAD characteristics and the relationship to ventricular arrhythmias (nonsustained/sustained ventricular tachycardias and aborted cardiac arrest).

RESULTS

We included 84 patients (mean age: 48 ± 16 years; 63% female). We observed TAD in 42 (50%). Patients with TAD were older (age 52 ± 16 years vs. 43 ± 15 years; p = 0.02), had greater circumferential extent of MAD (164 ± 57° vs. 115 ± 58°; p = 0.002), greater maximum longitudinal MAD distance (9.4 ± 2.9 mm vs. 6.2 ± 2.8 mm; p < 0.001), and more frequent mitral valve prolapse (n = 39 [92%] vs. n = 24 [57%]; p < 0.001). Ventricular arrhythmias had occurred in 34 patients (41%), who were younger (age 39 ± 14 years vs. 54 ± 14 years; p < 0.001) and had lower prevalence of TAD (n = 22 [29%] vs. n = 12 [52%]; p = 0.03). TAD was not associated with ventricular arrhythmias when adjusted for age (odds ratio adjusted for age: 0.54; 95% confidence interval: 0.20 to 1.45; p = 0.22).

CONCLUSIONS

We report for the first time the existence of right-sided annulus disjunction as a common finding in patients with MAD. TAD was associated with more severe left-sided annulus disjunction and mitral valve prolapse, but not with ventricular arrhythmias.

Prevalence and characteristics of mitral valve prolapse in military young adults in Taiwan of the CHIEF Heart Study

The prevalence of mitral valve prolapse (MVP) among middle- and older-aged individuals is estimated to be 2–4% in Western countries. However, few studies have been conducted among Asian individuals and young adults. This study included a sample of 2442 consecutive military adults aged 18–39 years in Hualien, Taiwan. MVP was defined as displacement of the anterior or posterior leaflet of the mitral valve to the mid portion of the annular hinge point > 2 mm in the parasternal long-axis view of echocardiography. Cardiac chamber size and wall thickness were measured based on the latest criteria of the American Society of Echocardiography. The clinical features of participants with MVP and those without MVP were compared using a two-sample t test, and the cardiac structures were compared using analysis of covariance with adjustment for body surface area (BSA). Eighty-two participants were diagnosed with MVP, and the prevalence was 3.36% in the overall population. Compared with those without MVP, participants with MVP had a lower body mass index (kg/m²) (24.89 ± 3.70 vs. 23.91 ± 3.45, p = 0.02) and higher prevalence of somatic symptoms related to exercise (11.0% vs. 4.9%, p = 0.02) and systolic click in auscultation (18.3% vs. 0.6%, p < 0.01). In addition, participants with MVP had greater left ventricular mass (gm) and smaller right ventricular wall thickness (mm) and dimensions (mm) indexed by BSA than those without MVP (149.12 ± 35.76 vs. 155.38 ± 36.26; 4.66 ± 0.63 vs. 4.40 ± 0.68; 26.57 ± 3.99 vs. 25.41 ± 4.35, respectively, all p-values < 0.01). In conclusion, the prevalence and clinical features of MVP in military young adults in Taiwan were in line with those in Western countries. Whether the novel MVP phenotype found in this study has any pathological meaning needs further investigation.

Echocardiographic screening for mitral valve prolapse in Turkish school children

We determined the frequency of mitral valve prolapse (MVP) in healthy Turkish school children using the current echocardiographic diagnostic criteria. This epidemiological survey was performed on 2550 school children. All children were screened with echocardiography and the family of children with MVP were also screened. The prolapse of mitral leaflets into left atrium ≥ 2 mm in parasternal long-axis view was used as diagnostic criteria. MVP was classified as classical or non-classical according to anterior mitral leaflet thickness. The thickness of anterior mitral leaflet, the extent of prolapse, and the presence of mitral regurgitation were evaluated. The children were also questioned about the associated symptoms. The prevalence of MVP was 1.25% in children with a mean age of 11.1 ± 2.9 years. The prevalence was 0.9%, 1.2%, and 1.6% in 5-9 years, 10-13 years, and 14-18 years of age, respectively. 43.7% of the cases were classical MVP. The frequency of auscultation findings was 34.3%. 11/34 children had mitral regurgitation. There was no statistically significant difference between classical MVP and non-classical MVP in terms of mitral regurgitation, physical examination findings, and symptoms. Anxiety (37.5%) was the most common symptom. The frequency of MVP in the first-degree relatives of children with MVP was 11/84 (13.1%). Most patients with MVP don't have auscultation findings and symptoms, therefore echocardiography is an important tool in the diagnosis of MVP. It is also reasonable to screen first degree relatives of MVP patients with echocardiography.

The Use of MitraClip in Secondary Mitral Regurgitation and Heart Failure

Secondary (also known as functional) mitral regurgitation (MR) has increased substantially over the last several decades due to an increase in the prevalence of dilated cardiomyopathy (ischemic and non-ischemic). Mortality and morbidity in patients with dilated cardiomyopathy is much greater when associated with MR as compared to without MR. MR will result in further left ventricular (LV) volume overload, LV dilation, and pupillary muscle displacement resulting in deterioration of the severity of MR leading to a vicious cycle. Optimization of heart failure medical therapy, and cardiac resynchronization therapy for those that qualify, can improve severity of MR; however, significant MR will persist in certain patients. Transcatheter mitral valve repair to treat significant MR using the MitraClip (Abbott, Menlo Park, California), which grasps and coapts the posterior and anterior mitral valve leaflets, in appropriately selected patients with dilated cardiomyopathy and secondary MR has been shown to improve quality of life and prolong survival.