Posterior Mitral Leaflet Research Articles

Sex-based differences in anatomical and hemodynamic parameters and outcomes in patients with hypertrophic cardiomyopathy undergoing alcohol septal ablation

Abstract Background This study aimed to assess sex differences in anatomical and hemodynamic parameters, and in procedure related outcomes, in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). Methods 154 patients that underwent ASA in at our university hospital, between 2009 and 2021, were retrospectively included. Anatomical and hemodynamic parameters were collected from invasive catheterization before and during ASA, and from echocardiography (ECHO) examinations at maximum one week before ASA. Follow-up was conducted one year after ASA. The parameters analyzed were left ventricular (LV) volume, basal septal wall thickness (BSWT), anterior (AML) and posterior mitral leaflet (PML) length, minimal left ventricle outflow tract (LVOT) diameter, and LVOT pressure gradient at rest, prior to ASA, and prevalence of atrioventricular block after ASA. Linear and logistic regression models were used to assess the sex differences between the parameters. Results 50% of the patients were women. At the time of ASA, women were significantly older, had lower LV volume indexed for BSA in end-diastole (44 vs. 54 ml, p<0.001) and end-systole (18 vs. 23 ml, p=0.021), longer AML length indexed for BSA (13.7 vs. 11.6 mm, p<0.001) and PML length indexed for BSA (8.8 vs. 8.1 mm, p=0.018), smaller minimal LVOT diameter (4.6 vs. 4.9 mm, p=0.042), and higher LVOT pressure gradient at rest (49.3 vs. 32.5 mmHg, p=0.014), compared with men. The median follow-up was 364 days. Atrioventricular block (II or III) was more common among women (n=20, 26%) compared with men (n=10, 13%, p=0.045). Conclusions ECHO and invasive catheterization prior to ASA showed that women with HOCM presented with less favorable anatomical and hemodynamic pre-conditions, compared with men. At follow-up, women had a greater incidence of atrioventricular block after ASA. This strongly emphasizes the need for a sex-specific approach to optimize care and improve outcomes in patients with HOCM.

Residual mitral leaflet length independently indicates left ventricular outflow tract obstruction in hypertrophic cardiomyopathy

Abstract Background Due to its dynamic character, the diagnosis of left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM) often requires extensive exercise testing. Mitral valve alterations represent structural parameters that are not affected by load or contractility and influence left ventricular outflow tract (LVOT) gradients. The residual portion of the mitral valve extending past its coaptation (RML) has been postulated as a necessity to exhibit LVOTO. Purpose This study aims to assess the impact of RML length on the likelihood of LVOTO in HCM patients. Methods This is a cross-sectional, multi-center, registry-based analysis conducted at two HCM referral centers. The study included HCM patients with valid standardized transthoracic echocardiographic examinations. Blinded investigators performed post-processing echocardiographic analyses. LVOTO was defined as resting or dynamic peak LVOT gradients ≥30 mmHg. Results Among 270 HCM patients studied (43% women, mean age 58±14 years), 131 patients (49%) exhibited LVOTO, with 76 (28%) having undergone septal reduction therapy (SRT). Patients with obstructive HCM exhibited a more pronounced end-diastolic interventricular septum (IVSd) thickness (2.2±0.4 vs. 1.8±0.5 cm; p<0.001) and higher left ventricular ejection fraction (LVEF) (65±9 vs. 62±10%; p=0.009) compared to those without LVOTO (nHCM). Obstructive HCM patients demonstrated longer anterior (29±4 vs. 26±4 mm; p<0.001), posterior (23±4 vs. 20±4 mm; p<0.001), and residual mitral leaflets (11±3 vs. 7±3 mm; p<0.001) than nHCM patients. Multivariable logistic regression analysis adjusting for age, IVSd thickness, LVEF, anterior, and posterior mitral leaflet length identified RML length as an independent predictor of LVOTO [OR=1.47 (95% CI 1.30-1.66); p<0.001]. The area under the receiver-operating characteristic curve for RML length in identifying LVOTO was 0.82 (95% CI 0.77-0.87). RML length ≥9 mm demonstrated 73% sensitivity and 77% specificity in identifying obstructive HCM patients. Notably, these results remained statistically significant in sensitivity analyses selectively performed in HCM patients who had previously undergone SRT as well as in those who were SRT-naïve, respectively. Conclusions This study indicates RML length as an independent predictor of LVOTO in HCM patients. Moreover, RML length demonstrated high diagnostic accuracy in identifying LVOTO among HCM patients. Prospective studies are warranted to assess the added value of RML length in the diagnostic work-up of HCM patients.Figure:Diagnostic Accuracy of RML

Mitral valve phenotypes in SMAD3-related thoracic aortic disease: insights from the Montalcino Aortic Consortium

Abstract Background SMAD3 pathogenic variants (PV) predispose to heritable thoracic aortic aneurysms and dissections (HTAD). Mitral annular disjunction (MAD) associated with mitral valve prolapse (MVP) and mitral regurgitation (MR) was identified as a potential new marker of disease severity in Marfan syndrome. The prevalence and prognostic impact of these mitral phenotypes in other forms of HTAD are less known. Purpose We hypothesize that mitral abnormalities are increased in SMAD3-related HTAD and are associated with increased risk for valve and aortic complications. Methods The Montalcino Aortic Consortium (MAC) registry has enrolled participants with PV in 15 HTAD genes. Subjects >16 years old with complete imaging and clinical data were included in this study. MVP was defined according to current guidelines. MR was classified as mild, moderate, or severe. MAD was defined by a >3-millimeter gap between the posterior mitral valve leaflet hinge point and the inferolateral myocardium as confirmed by direct measurement of echocardiogram images. Frequencies of MVP, MR, and MAD were compared between MAC participants with SMAD3 PV and other HTAD PV. Associations between clinical and echo characteristics and the composite outcome of arrhythmia, aortic surgery, aortic dissection, or congestive heart failure was evaluated with multivariable logistic regression. Results In 671 MAC participants (129 with SMAD3 PV, 36 [IQR 19-51] years, 49% female), the prevalence of MVP was 15% and the prevalence of MR was 22%. Both MVP (31/129, 24%, vs. 67/542, 12%, OR 2.2 [1.4-3.6], P<0.001) and MR (40/129, 31%, vs. 108/542, 20%, OR 1.8 [1.2-2.8], P<0.006) were more common in participants with SMAD3 PV compared to other PV and were further enriched in cases with SMAD3 missense PV compared to loss of function PV (MR or MVP: 26/48, 54% vs. 7/30, 23%, OR 3.9 [1.4-10.8], P<0.007). Images were available from 238 MAC participants (67 with SMAD3 PV) to assess for MAD. MAD (29/67, 43%, vs. 28/171, 16%, OR 3.9 [2.1-7.3], P<0.0001), or the composite of MR, MVP, or MAD (42/67, 63%, vs. 69/171, 35%, OR 3.2 [1.8-5.7], P<0.0001) was more common with SMAD3 PV compared to other PV (Figure 1). Twelve participants with SMAD3 PV (18%) had prominent mitral phenotypes (>mild MR, >10 mm MAD, or MAD with MVP) but no significant aortic dilation (Z<3). When controlling for age and sex, MR or MVP, but not MAD, was independently associated with the composite outcome (OR 16 [2.4-110], Figure 2). Conclusion Mitral valve pathology, including MVP, MR, and MAD, is increased in individuals with SMAD3 PV compared to other HTAD PV. Prominent mitral phenotypes related to SMAD3 missense PV may identify a high-risk subgroup with adverse cardiovascular outcomes. Because congenital mitral disease may be the primary presenting feature of SMAD3 PV, genetic testing for HTAD should be considered for such patients, especially if they also have a family history of thoracic aortic disease.

Predictors and Clinical Outcomes of True Mitral Stenosis in Patients Undergoing Transcatheter Aortic Valve Implantation

Abstract Aims Predictors of true degenerative mitral stenosis (MS) in patients with aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) remain unknown. This study aimed to investigate the predictors and prognostic value of true degenerative MS in this population. Methods and results We retrospectively reviewed the records of 760 consecutive patients who underwent TAVI. The mitral valve area (MVA) was assessed using transthoracic echocardiography, and mitral valve calcification was assessed using multi-detector computed tomography. MS was defined as an MVA of ≤2.0 cm², and true MS was defined as moderate or severe MS following TAVI. In our TAVI cohort, we identified 72 (9.5%) patients with degenerative MS. Among these, true MS was observed in 38 (52.7%) patients. Echocardiographic data showed that the true MS group had a significantly lower MVA and higher trans-mitral gradient. The severity of mitral annular calcification was not significantly different between the two groups; however, the true MS group had significantly more posterior mitral leaflet (PML) and anterior mitral leaflet (AML) calcification. Multivariable logistic regression analysis showed that AML calcification was the independent predictor of true MS (adjusted OR, 9.23; 95% CI 2.84‒29.9). True MS was independently associated with poor prognosis (adjusted HR, 2.76; 95% CI 1.09‒6.98). Conclusions Approximately half of patients with concomitant degenerative MS who underwent TAVI had true MS, which was associated with a poor prognosis. Computed tomographic analysis of AML calcification was useful for predicting true MS.

Isolated prolapse of the posterior mitral valve leaflet: phenotypic refinement, heritability and genetic etiology.

Isolated posterior leaflet mitral valve prolapse (PostMVP), a common form of MVP, often referred as fibroelastic deficiency, is considered a degenerative disease. PostMVP patients are usually asymptomatic and often undiagnosed until chordal rupture. The present study aims to characterize familial PostMVP phenotype and familial recurrence, its genetic background, and the pathophysiological processes involved. We prospectively enrolled 284 unrelated MVP probands, of whom 178 (63%) had bi-leaflet MVP and 106 had PostMVP (37%). Familial screening within PostMVP patients allowed the identification of 20 families with inherited forms of PostMVP for whom whole genome sequencing was carried out in probands. Functional in vivo and in vitro investigations were performed in zebrafishand in Hek293T cells. In the 20 families with inherited form of PostMVP, 38.8% of relatives had a MVP/prodromal form, mainly of the posterior leaflet, with transmission consistent with an autosomal dominant mode of inheritance. Compared with control relatives, PostMVP family patients have clear posterior leaflet dystrophy on echocardiography. Patients with PostMVP present a burden of rare genetic variants in ARHGAP24. ARHGAP24 encodes the filamin A binding RhoGTPase-activating protein FilGAP and its silencing in zebrafish leads to atrioventricular regurgitation. In vitro functional studies showed that variants of FilGAP, found in PostMVP families, are loss-of-function variants impairing cellular adhesion and mechano-transduction capacities. PostMVP should not only be considered an isolated degenerative pathology but as a specific heritable phenotypic trait with genetic and functional pathophysiological origins. The identification of loss-of-function variants in ARHGAP24 further reinforces the pivotal role of mechano-transduction pathways in the pathogenesis of MVP. Isolated posterior mitral valve prolapse (PostMVP), often called fibro-elastic deficiency MVP, is at least in some patients, a specific inherited phenotypic traitPostMVP has both genetic and functional pathophysiological origins Genetic variants in the ARHGAP24 gene, which encodes for the FilGAP protein, cause progressive Post MVP in familial cases, and impair cell adhesion and mechano-transduction capacities.

Evaluation of potential links between phenotypic features and genetic variants in left ventricular outflow tract obstruction in hypertrophic cardiomyopathy using cardiovascular magnetic resonance imaging.

This study aimed to identify the phenotypic features contributing to the development of left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM) and to evaluate the genotype‒phenotype relationship. This cross-sectional study included 96 patients diagnosed with HCM (mean age: 56.9 ± 13.5 years, 32.3% female). The patients were divided into hypertrophic nonobstructive cardiomyopathy (HNCM; n = 60) and hypertrophic obstructive cardiomyopathy (HOCM; n = 36) groups. All patients underwent CMR. Patients (n = 77) who had previously provided formal approval underwent a genetic examination that included 18 genes. The anterior mitral leaflet (AML) length/LVOT diameter ratio, posterior mitral leaflet (PML) length/LVOT diameter ratio, and anterolateral papillary muscle (AL-PM) mobility were associated with LVOTO, independent of the basal IVS thickness, abnormal chordal attachment, and bifid PM. An AML length/LVOT diameter ratio of ≥ 2.30, a PML length/LVOT diameter ratio of ≥ 1.83, and an AL-PM mobility of ≥ 57.7% were predictors of LVOTO, with good sensitivity and specificity. Positive variants (VUS, LP, and P) were detected in 37.7% (29 of 77) of the patients who underwent genetic testing. The LP/P variant was detected in 20.8% (16 of 77) of patients. Three groups (variant-negative, VUS, and LP/P groups) had significant differences in the LVOT diameter (median 14, 12, and 10mm, respectively; p = 0.021), AML length (mean 25.3, 26.5, and 27.5mm, respectively; p = 0.029), AML length/LVOT diameter ratio (median 1.74, 2.33, and 2.85, respectively; p = 0.006), PML length/LVOT diameter ratio (median 1.29, 1.82, and 2.10, respectively; p = 0.045), and abnormal chordal attachment (6.3%, not observed, and 31.3%, respectively; p = 0.009). The AML length/LVOT diameter ratio, PML length/LVOT diameter ratio, and AL-PM mobility were associated with LVOTO. In addition, genetic testing results may provide information regarding the phenotypic expression of patients with HCM.

Endomyocardial involvement in asymptomatic Latin American migrants with eosinophilia related to helminth infection: A pilot study.

Hypereosinophilic syndrome can produce cardiac involvement and endomyocardial fibrosis, which have a poor prognosis. However, there is limited information regarding cardiac involvement among migrants from Latin America with eosinophilia related to helminthiasis. We conducted a pilot observational study where an echocardiography was performed on migrants from Latin America with both eosinophilia (>450 cells/μL) and a diagnosis of helminth infection, and on migrants from Latin America without eosinophilia or helminth infection. Microbiological techniques included a stool microscopic examination using the Ritchie's formalin-ether technique, and a specific serology to detect Strongyloides stercoralis antibodies. 37 participants were included, 20 with eosinophilia and 17 without eosinophilia. Twenty (54.1%) were men with a mean age of 41.3 (SD 14.3) years. Helminthic infections diagnosed in the group with eosinophilia were: 17 cases of S. stercoralis infection, 1 case of hookworm infection, and 2 cases of S. stercoralis and hookworm coinfection. Among participants with eosinophilia, echocardiographic findings revealed a greater right ventricle thickness (p = 0.001) and left atrial area and volume index (p = 0.003 and p = 0.004, respectively), while showing a lower left atrial strain (p = 0.006) and E-wave deceleration time (p = 0.008). An increase was shown in both posterior and anterior mitral leaflet thickness (p = 0.0014 and p = 0.004, respectively) when compared with participants without eosinophilia. Migrants from Latin America with eosinophilia related to helminthic infections might present incipient echocardiographic alterations suggestive of early diastolic dysfunction, that could be related to eosinophilia-induced changes in the endomyocardium.

Impact of Complex Anatomy and Patient Risk Profile in Minimally Invasive Mitral Valve Surgery

BackgroundWe aimed to assess the impact of complex mitral valve disease and patient risk profile on operative outcomes in the large cohort of the Mini-Mitral International Registry. MethodsPatients were assigned to categories of complex degenerative mitral valve regurgitation (DMR; bileaflet or anterior mitral leaflet prolapse/flail) and simple DMR (posterior mitral leaflet prolapse/flail). Subgroup analyses was performed in low-risk (EuroSCORE II <8%) and high-risk (EuroSCORE II >8%) cohorts. A logistic regression model was applied to investigate the impact of valve anatomy and patient risk factors on valve repair rate and operative risk. ResultsThe study cohort consisted of 4524 patients with DMR (complex DMR, 1296; simple DMR, 3228). Valve repair rate was 87.3% and 91% in complex DMR and simple DMR, respectively. Predictors of valve replacement were anterior leaflet prolapse/flail, bileaflet flail, female sex, age, and reoperation, whereas Barlow disease was protective. Clinical results were comparable between complex DMR and simple DMR. On subgroup analyses, high-risk patients showed less satisfactory outcomes with respect to both the valve repair and operative mortality rates. ConclusionsOur findings suggest that complex DMR can be satisfactorily addressed by minimally invasive techniques. However, whereas complex disease was associated with low operative risk, anterior leaflet lesions and bileaflet flail remain negative predictors of successful valve repair. Conversely, valve repair rate was less satisfactory in high-risk patients, regardless of DMR complexity.

Atrial Functional Mitral Regurgitation Subtypes Undergoing Transcatheter Edge-to-Edge Repair: Suboptimal Outcomes in Atriogenic Hamstringing.

Two subtypes of atrial functional mitral regurgitation (AFMR) have been described, one is characterized by Carpentier type I and the other by Carpentier type IIIb leaflet motion. The authors sought to analyze echocardiographic characteristics and outcomes of AFMR subtypes undergoing mitral valve transcatheter edge-to-edge repair (M-TEER). Of 1,047 consecutive patients who underwent M-TEER, the authors identified those with isolated mitral annulus dilation (Carpentier I), termed AFMR-IAD, and those with atriogenic hamstringing characterized by restricted posterior mitral leaflet motion (Carpentier IIIb), termed AFMR-AH. Echocardiographic baseline characteristics and outcomes up to 1-year were analyzed. A total of 128 patients (12.2%) met AFMR criteria; 75 (58.6%) were identified as AFMR-IAD and 53 (41.4%) as AFMR-AH. AFMR-AH displayed greater left atrial and left ventricular volumes, greater mitral annulus, shorter and steeper posterior mitral leaflet, and more pronounced MR (all P< 0.05). Technical success was achieved in 98.7% (AFMR-IAD) and 86.8% (AFMR-AH) of patients (P = 0.009). At discharge, device detachments were exclusively observed in AFMR-AH (10.0%). MR≤II was achieved in 95.6% and 78.6% at 30days (P=0.009) and in 93.0% and 74.1% at 1 year (P = 0.038) in patients with AFMR-IAD and AFMR-AH, respectively. AFMR-AH was associated with procedural failure (OR: 1.17 [95%CI: 1.00-1.38]; P = 0.045) at 30days (43.4% vs 24.0%; P = 0.023) and all-cause mortality (HR: 2.54 [95%CI: 1.09-5.91]; P = 0.031) at 1 year (77% vs 92%, Kaplan-Meier estimated 1-year survival; P = 0.017). AFMR-AH shows worse procedural and clinical outcomes following M-TEER than AFMR-IAD. Thus, vigilance regarding this pathology is warranted and alternative mitral valve therapies might need to be considered.

Three-dimensional anatomic features of the mitral valve that predict systolic anterior motion occurring during dobutamine stress echocardiography.

Left ventricular outflow tract obstruction related to systolic anterior motion (SAM) of the mitral valve is a common complication of dobutamine stress echocardiography (DSE). However, the mechanisms underlying SAM have not been fully characterized. The objective of the present study was to use three-dimensional echocardiography to identify anatomic features of the mitral valve that predispose to SAM during DSE. We retrospectively evaluated consecutive patients included prospectively in our database and who had undergone 3D echocardiography (including an assessment of the mitral valve) before DSE. Patients who had developed SAM during DSE (the SAM+ group) were matched 2:3 with patients who did not (the SAM- group). One hundred patients were included (mean age: 67±10). Compared with SAM- patients (n=60), SAM+ patients (n=40) had a lower mitral annular area, a smaller perimeter, and a smaller diameter (p<.01 for all, except the anteroposterior diameter). The SAM+ group had also a narrower mitral-aortic angle (126±12° vs. 139±11° in the SAM- group; p<.01) and a higher posterior mitral leaflet length (1.4±.27cm vs. 1.25±.29, respectively; p<.01). Furthermore, the mitral annulus was more spherical, more flexible, and more dynamic in SAM+ patients than in SAM- patients (p<.05 for all). In a multivariate analysis of anatomic variables, the mitral-aortic angle, the mitral annular area, and posterior leaflet length were independent predictors of SAM (p ≤ .01 for all). In a multivariate analysis of standard echo and hemodynamic variables, the presence of wall motion abnormalities at rest (p<.01) was an independent predictor of SAM. SAM during DSE is multifactorial. In addition to the pharmacologic effects of dobutamine on the myocardium, 3D echocardiographic features of the mitral valve (a smaller mitral annulus, a narrower mitral-aortic angle, and a longer posterior leaflet) appear to predispose to SAM.

Incidental Findings of Congenital Unileaflet Mitral Valves in Young Patient Presenting Complete Atrioventricular Block.

The singular leaflet mitral valve is a rare and complex entity that has been described in only a few case reports. It is commonly observed in infancy and combined with symptomatic mitral regurgitation (MR). In most asymptomatic individuals, this complication is attributed mainly to a hypoplastic posterior mitral leaflet and is usually revealed in adulthood. We present the case of a 30-year-old man who presented with chest pain and dyspnea for two days. The electrocardiogram showed complete atrioventricular block with a beat rate of 30 bpm.Echocardiography revealed an elongated anterior mitral valve leaflet and an almost completely absent posterior mitral valve leaflet with no MR. Our case is unusual presentation of a unileaflet mitral valve that should be investigated even in adulthood as these patients are likely to be at risk of developing or worsening MR later in life; hence, performing periodic echocardiograms is important for detecting the progression of MR early.

Mitral valve repair with leaflet resection versus preservation for degenerative posterior leaflet prolapse

ObjectivesThe optimal technique for repairing posterior mitral valve leaflet prolapse remains undetermined. We aimed to compare leaflet resection and neochordae implantation in patients undergoing mitral valve repair for posterior leaflet prolapse, focusing on transmitral pressure gradient and recurrence of mitral regurgitation. MethodsWe enrolled patients undergoing mitral valve repair using either leaflet resection or neochordae implantation for single-segment prolapse of posterior mitral valve leaflet between 2000 and 2021 at our institution. Longitudinal outcomes were evaluated after adjustments with inverse-probability-of-treatment weighting. Repeat echocardiographic measurements (n = 3473, 5.4/patient) of transmitral pressure gradient and significant (moderate or severe) mitral regurgitation recurrence were estimated using nonlinear mixed-effect models. Subgroup analyses were conducted based on the size and type of prosthesis. ResultsAmong 639 patients, leaflet resection was used in 479 (75.0%) and neochordae implantation was used in 160 (25.0%). In the inverse-probability-of-treatment weighting adjusted cohort, the risk of death (P = .623) and mitral valve reoperation (P = .340) did not significantly differ between the 2 groups during a median follow-up of 97.3 months. Echocardiographic data showed comparable mean (at 5 years, 3.8 vs 4.0 mm Hg; P = .442) and peak (9.6 vs 10.4 mm Hg; P = .131) pressure gradients between groups, which persisted in most subgroup analyses. However, neochordae implantation was associated with a higher probability of significant mitral regurgitation recurrence compared with leaflet resection (at 5 years, 16.1% vs 7.0%; P < .001). ConclusionsLeaflet resection yielded similar clinical outcomes and transmitral pressure gradients compared with neochordae implantation after mitral valve repair, with a lower mitral regurgitation recurrence rate. These findings underscore the need to reassess the efficacy of neochordae implantation relative to leaflet resection.

Changes in left ventricular-aortic angulation are associated with the development of obstruction in hypertrophic cardiomyopathy

ObjectiveTo characterize changes in ventricular morphology in patients with hypertrophic cardiomyopathy who develop left ventricular (LV) outflow tract obstruction. MethodsWe reviewed patients with hypertrophic cardiomyopathy with LV outflow tract obstruction who underwent septal myectomy from May 2012 to June 2023. Among 68 patients initially without obstruction documented up to 7.6 years (interquartile range, 6.3-9.4 years) before the operation, a comparison was made with 78 patients with nonobstructive hypertrophic cardiomyopathy over a similar period. Patients who did not develop obstruction were matched with those who did on sex, age, and maximum septal wall thickness during the initial echocardiography, identifying 41 matched pairs. Echocardiographic data, including 5 measures of angulation, were compared between the groups. ResultsThe median interval between echocardiographic assessments was 7.5 years (interquartile range, 6.3-8.1 years) among patients with obstruction versus 7.3 years (interquartile range, 6.2-9.0 years) in patients without nonobstruction. Patients with obstruction were more likely to have hypertension at both times. The maximum septal wall thickness increased within both groups (both P values < .001), but the magnitude of increase was not different between groups (P = .130). Patients with obstruction exhibited a greater increase in LV mass (P < .001) compared with patients without obstruction (P = .004). Aortic angulation significantly increased in 4 of the 5 measurements (all P values < .001) in patients with obstruction, whereas patients with no obstruction showed no change. Anterior and posterior mitral valve leaflet lengths and coaptation lengths remained similar in both groups over time. ConclusionsThe development of LV outflow tract obstruction in patients with hypertrophic cardiomyopathy was associated with progressive LV outflow tract angulation and increased LV hypertrophy, as reflected by LV mass. Progression to obstruction was not related to changes in the mitral valve leaflet morphology.

Mutation in PDGFRbeta: a potential new pathogenic variant for acquired mitral valve prolapse

Abstract Funding Acknowledgements None. Background Mitral valve prolapse (MVP) due to myxomatous degeneration is characterized by familial clustering, but few pathogenic genes have been identified. In a genetic screening program for MVP patients, we identified a platelet-derived growth factor receptor β (PDGFRβ)-E162K missense variant in a family with a bi-leaflet MVP phenotype in four affected family members. PDGFRβ is a receptor tyrosine kinase, which plays an important role in vascular development. Purpose In this study, we investigated whether the E162K substitution in PDGFRβ could lead to mitral valve abnormalities. Methods To assess the functional effects of the missense variant, proliferation and migration assays were performed using HeLa cells overexpressing wild-type (WT) or mutant PDGFRβ. Immunostainings were performed to determine PDGFRβ expression in the diseased valves from a family member undergoing surgical operation and from additional patients operated for MVP. Mouse models were created with the mouse equivalent of the human PDGFRβ-E162K variant (PDGFRβ-E161K) using CRISPR/CAS9. The variant was not lethal and transthoracic echocardiography was performed on adult homozygous PDGFRβE161K/E161K mice, heterozygous PDGFRβE161K/- mice, and WT mice . In addition, histology was performed in adult and neonatal mice to detect potential valvular defects. Results HeLa cells expressing PDGFRβ-E162K and stimulated with PDGFD showed reduced proliferation and migration, suggesting a loss of function of the mutant receptor. PDGFRβ was expressed in human diseased mitral valves. Echocardiographic evaluation revealed a significant larger mitral valve annulus diameter in both PDGFRβE161K/- and PDGFRβE161K/E161K compared to WT (WT: 1.97 mm; PDGFRβE161K/-:2.13, p=0.031; PDGFRβE161K/E161K:2.42 mm, p&amp;lt;0.0001). Histological data in PDGFRβE161K/E161K mice showed significant leaflet thickening in the free edge (FE) of the posterior mitral valve leaflet (PMVL) compared to WT (WT: 72.34 ɥm; PDGFRβE161K/E161K: 109.6 ɥm, p=0.040) and a larger leaflet area of the PMVL compared to WT (WT: 25280 ɥm²; PDGFRβE161K/E161K: 44494 ɥm², p=0.020). Moreover, an altered organization of the extracellular matrix reminiscent of the myxomatous degeneration in MVP was observed. These alterations were not observed in mutant neonatal hearts. Conclusions The PDGFRβ-E162K variant is associated with familial MVP and alters the function of PDGFRβ. Mice harboring this mutation display acquired mitral valve defects.

Alcohol septal ablation for hypertrophic obstructive cardiomyopathy: do mitral valve leaflet length, septal thickness, or sex affect the outcome?

This retrospective cohort study aimed to assess whether basal septal wall thickness (BSWT), anterior (AML) and posterior (PML) mitral leaflet length, or sex were associated with remaining left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). One hundred fifty-four patients who underwent ASA at the Karolinska University Hospital in Stockholm, Sweden, between 2009 and 2021, were included retrospectively. Anatomical and hemodynamic parameters were collected from invasive catheterization before and during ASA, and from echocardiography (ECHO) examinations before, during, and at 1-year follow-up after ASA. Linear and logistic regression models were used to assess the association between sex, BSWT, AML, PML, and outcome, which was defined as the remaining LVOTO (≥ 30 mmHg) after ASA. The median follow-up was 364 days (interquartile range 334–385 days). BSWT ≥ 23 mm (n = 13, 12%) was associated with remaining LVOTO at follow-up (p = 0.004). Elongated mitral valve leaflet length (either AML or PML) was present in 125 (90%) patients. Elongated AML (> 24 mm) was present in 67 (44%) patients, although AML length was not associated with remaining LVOTO at follow-up. Elongated PML (> 14 mm) was present in 114 (74%) patients and was not associated with remaining LVOTO at follow-up. No significant sex differences were observed regarding the remaining LVOTO. ECHO measurement of BSWT can be effectively used to select patients for successful ASA and identify those patients with a risk of incomplete resolution of LVOTO after ASA.Graphical abstract

HOW TO MANAGE MITRAL VALVE POSTERIOR LEAFLET HYPOPLASIA

Abstract Background Mitral valve posterior leaflet hypoplasia is a relatively rare and often congenital anatomical malformation. In this condition, achieving a good and durable mitral valve repair still represents a challenge for surgeons. Methods We present the case of a 43 years old man presenting with exertional dyspnoea due to severe mitral regurgitation. Transthoracic and transesophageal echocardiograms revealed a severe hypoplasia of the posterior mitral leaflet with an significant prolapse of the anterior leaflet (particularly A2–A3), which determined massive regurgitation. The anteroposterior annular diameter was 38 mm with a 4 mm mitro–anular disjunction, left ventricular telediastolic diameter was 59 mm and ejection fraction 68%. No other cardiac malformations were evident; in particular tricuspid valve was normal. Results Surgery was performed through a right mini–thoracotomy with femoral cannulation, using three–dimensional video–assisted technology. The mitral valve was approached from the left atrium, behind the interatrial groove. Surgical inspection revealed a severely hypoplasic posterior leaflet and a wide anterior leaflet prolapsing near the postero–medial commissure (A2–A3) (Figure 1). Based on our previous experience, we decided to repair the valve performing a posterior para–commissural edge–to–edge (A3–P3) followed by an atypical annuloplasty using a bovine pericardium band, shaped on a 40 mm ring sizer, only in the postero–medial portion of the mitral annulus (Figure 2). On the hydrostatic test, the valve showed a satisfactory continence, that was confirmed on the intraoperative TEE. Postoperative course was uneventful and the patient was discharged home on postoperative day 7. Transthoracic echocardiography at discharge showed a good result of the mitral valve repair with no residual regurgitation a medium gradient across the mitral valve of 3 mmHg. Conclusions In our experience, reductive annuloplasty isn’t the optimal treatment for hypoplasic mitral valve posterior leaflet because it lowers the already small posterior leaflet, thus reducing the coaptation surface. To avoid this, we introduced this technique that improved our surgical outcomes.

IATROGENIC ACUTE MITRAL INSUFFICIENCY FOLLOWING IMPELLA–ASSISTED INTERVENTIONAL PROCEDURE

Abstract Background Short–term left ventricle mechanical assistance device could be useful in assist interventional cardiologist during high–risk procedures. Abiomed Impella is one of the most frequently used device in this respect due to the high flow available with a low rate of reported complications. Here we report a rare but potentially catastrophic complication related to the Impella device. Case Description A 78 years old patient was referred to our Division by a peripheral hospital for a severe, symptomatic (NYHA III) mitral regurgitation (MR) due to posterior mitral leaflet prolapse (with focal eversion of P3) and chordal rupture (Fig 1a). Medical history included a previous admission in the some hospital due to a scheduled Impella–assisted PTCA (left main/left anterior descending artery) . Pre–procedural trans–thoracic ECHO (TTE) did not show significant MR (Fig 1b). Results Patient underwent urgent surgical procedure. At operation postero–medial mitral commissure was seen to be completely everted with multiple rupture of P3 and A3 chordae. Surgical procedure (Fig 1c) included: P3 plication + posterior–medial commissure edge–to–edge plasty + complete mitral semi–rigid ring (Simulus) n.30. Left atrial appendage was also closed using an external Atriclip. Postoperative course was without significant complications except a superficial wound dehiscence which delayed hospital discharge till 20th postoperative day. Conclusion Despite being a feasible and attractive option for short–term mechanical circulation assistance during high–risk interventional procedure, Impella device insertion could cause significant mitral valve damage leading to clinical deterioration. Such potentially catastrophic complication should be, therefore, mandatory excluded before patient discharge following interventional procedure.

An unusual presentation of subacute Haemophilus parainfluenzae endocarditis in a low-risk woman treated by minimally invasive mitral valve repair: a case report

BackgroundHACEK endocarditis is usually insidious and can often be difficult to diagnose due to the slow-growing nature of the organisms. This report presents our experience in treating a patient with Haemophilus parainfluenzae endocarditis.Case presentationWe describe the case of a previously fit and well 23 year-old woman who presented to her local emergency department with a four-week history of persistent febrile illness. She had associated nausea, vomiting, and lethargy. This was preceded by an episode of mucopurulent rhinorrhoea. She was treated empirically with oral amoxicillin for a putative diagnosis of rhinosinusitis. Initially, her symptoms abated, however, she was readmitted with high fevers and a new pansystolic murmur. Transthoracic echocardiography revealed a large, mobile, echogenic mass, tethered to the posterior mitral valve leaflet (PMVL) and mild mitral regurgitation (MR). On examination, she had multiple non-tender, erythematous macules on the plantar surface of her feet, consistent with Janeway lesions. Two separate blood cultures grew H. parainfluenzae. Infectious diseases recommended a four-week course of intravenous ceftriaxone. Transesophageal echocardiography demonstrated a perforation within the P3 segment of the PMVL. Subsequently, the patient underwent mitral valve repair surgery with an uneventful recovery.ConclusionsOur case highlights the importance of promptly diagnosing HACEK endocarditis. A prolonged course of antibiotic therapy can be lifesaving, and surgery is often necessary to address complications such as perforation within the mitral valve leaflets. In our patient, we were able to perform a sliding P2 leaflet plasty for good quality repair of the mitral valve, through a minimally invasive right anterior thoracotomy.

E031 Retinal vasculitis with Libman-Sacks endocarditis as presenting features of a systemic lupus erythematosus with antiphospholipid antibody syndrome patient

Abstract Background/Aims Ocular manifestations of systemic lupus erythematosus (SLE) are rarely reported at the time of disease onset. Retinal vasculitis is usually associated with the active generalised disease. We report a case of a 22-year-old lady who was diagnosed with SLE with antiphospholipid antibody syndrome (APS) as the initial presentation of retinal vasculitis and Libman-Sacs endocarditis. Methods A 22-year-old lady with a background history of benign hypermobility spectrum disorder, presented to the eye casualty with a 4-week history of right-sided visual disturbances and was diagnosed with retinal vasculitis associated with uveitis, central retinal vein occlusion with multiple emboli in the retinal artery of the right eye and a single embolus in the left eye. In terms of family history, both father and brother were diagnosed with spondyloarthropathy, and the maternal uncle had Sjogren’s syndrome. She was then referred to the medical team for proper evaluation. On query, she mentioned photosensitive rash on her face getting worse in sunlight, a history of Raynaud’s phenomenon, significant hair loss, and one miscarriage before the 10 weeks of gestation. On examination, mild alopecia and a faint butterfly rash on the face were noted. Cardiac auscultation revealed pansystolic murmur. The rest of the systemic examinations were unremarkable. Results The blood test showed thrombocytopenia (130 u/L), positive antinuclear antibody (1:80, speckled pattern) with anti-double stranded DNA (26 IU/L), low complement (C3-0.74, C4- 0.12), markedly raised anticardiolipin antibody IgG (2016 u/ml), anti beta 2 glycoprotein 1 IgG ( &amp;gt;6100 u/ml) including presence of lupus anticoagulant. Her urinary protein creatinine ratio was 66mg/mmol. 3 sets of blood cultures came back negative. Transthoracic echo showed vegetation on the posterior mitral valve leaflet (0.95x 1.2cm) with moderate mitral regurgitation while transesophageal echo additionally found the possibility of perforation at the junction of leaflets of the mitral valve which was later confirmed by cardiac magnetic resonance imaging (MRI). The head MRI scan did not show any central nervous system abnormality. She was initially treated with 500mg intravenous methylprednisolone for 3 days followed by 20mg oral prednisolone daily with gradual tapering. Hydroxychloroquine and mycophenolate mofetil were added. Her case was discussed in the cardiology multidisciplinary team meeting and an opinion from the cardiothoracic surgery was taken to consider valve replacement in the future. Due to aspirin allergy, only warfarin was considered for APS. She had 2 sessions of pan-retinal photocoagulation as well. In subsequent follow-up, it was noted significant improvements in terms of her symptoms. Conclusion Vaso-occlusive retinopathy is a rare, potentially vision-threatening initial manifestation of SLE, which can be an indicator of active disease. Early identification of patients is necessary for timely intervention and multidisciplinary team involvement is required for comprehensive treatment plans. Disclosure M. Islam: None. S. Quddus: None. M. Hughes: None. R. Kumar: None.

Mitral valve leaflet blood cyst treated with minimally invasive approach: a case report and review of literature

IntroductionCardiac blood cyst is a very rare benign tumor of the heart in adults. Though it is very common in the first half year of life, it regresses with time and its occurrence is very rare in children older than six months and in adults. Until now less than 100 valvular blood cyst cases have been reported in adults.Case presentationWe present a case of a 66-year-old male who presented to us with exertional chest tightness, shortness of breath, and right leg weakness for two weeks. He was diagnosed with a cardiac mass two months ago in another hospital. The physical examination was unremarkable. Abdominal ultrasound showed a cyst in the liver and left kidney. Echocardiography showed a mass-occupying lesion of a cystic nature in the mitral valve with moderate mitral regurgitation. Based on echocardiography findings and computed tomography report, the preliminary diagnosis of mitral valve cystic tumor was made. The patient underwent minimally invasive resection of the cyst. The posterior mitral cusp was repaired and a mitral annuloplasty ring was placed. The postoperative recovery was uneventful. The histopathology report confirmed the diagnosis of a cardiac blood cyst. The patient was followed up for six months without any complications. This case is presented to enrich the medical literature on the cardiac blood cyst.ConclusionAlthough a cardiac blood cyst is a rare entity in adults, it still should be considered in the differential diagnosis of cardiac tumors. Because the natural history and hemodynamic effects are very diverse, large symptomatic cardiac blood cysts, especially in the left heart should be resected to avoid complications.