Anterior Leaflet Research Articles

Large Ostium Primum Interatrial Septum Defect in Asymptomatic Adult Athlete with Mitral Valve Prolapse and New Onset of Atrial Fibrillation

A large spectrum of congenital cardiac malformations can be the consequence of deficient formation of the embryonic atrioventricular canal by the endocardial cushions [1]. Among them, together with bicuspid aortic valve and mitral valve prolapse (MVP) [2], atrial septal defects (ASD) are one of the most frequent congenital heart diseases in adulthood. Differently from patients with secundum defects, ostium primum ASD are rarely reported in adulthood because those patients often require medical attention in pediatric age due to severity of symptoms. In ostium primum defect, in addition to the septal defect, the atrioventricular valves are often abnormal, including a cleft in the anterior mitral leaflet [3]. MVP is found in 30%-35% of ASD patients with or without significant mitral regurgitation (MR)and seems to be secondary to an abnormal left ventricular geometry and dilatated right ventricle which leads to shortening of inter-papillary distance and redundant chordae tendineae [4]. Atrial fibrillation (AF) is the most common cause of hospital admission among all arrhythmias in general population and AF is also the most common arrhythmia in the athletic population [5].

Biomechanical Evaluation of Mitral Valve Repair: Virtual Chordal Transposition to Restore Anterior Leaflet Prolapse.

Surgical management of an anterior leaflet prolapse remains comparatively challenging and has led to the lack of any firmly established standard repair techniques, as seen in cases of posterior leaflet prolapse. Chordal transposition repair is widely acknowledged as a remarkably durable technique that utilizes the patient's native chordae. This study aims to evaluate and predict the biomechanical and functional characteristics of a normal mitral valve (MV) model and a pathological MV model featuring anterior ruptured mitral chordae tendineae (RMCT), and to assess the effectiveness of the chordal transposition repair in the pathological MV model. There are four stages in the proposed virtual MV repair evaluation protocol: (1) modeling the virtual pathological MV model with an anterior (A2) RMCT; (2) performing chordal transposition as the virtual MV repair procedure; (3) dynamic finite element simulation of the normal (control) MV model, the pre-repair (pathological) MV model, and the post-repair (chorda transposition) MV model; (4) assessment and comparison of the physiological and biomechanical features among the normal, pre-repair, and post-repair cases. The pathological MV model with anterior RMCT clearly demonstrated a substantial flail, a marked increase in chordal stresses on the two intact chordae adjacent to the ruptured A2 chordae, and severe anterior leaflet prolapse due to the A2 chordal rupture. The virtual chordal transposition demonstrated remarkable efficacy in mitigating the stress concentrations in the leaflet and chordae, restoring leaflet coaptation, and resolving anterior leaflet prolapse. This virtual MV surgery strategy offers a valuable means to predict, evaluate, and quantify functional and biomechanical improvements before and after MV repair, thereby empowering informed decision-making in the planning of chordal transposition interventions.

Atrial septal defect occluder devices and embolization – a case series

Introduction: Atrial Septal Defect (ASD) secundum is a commonly occurring congenital heart disease. Patients with unstable hemodynamic may require closure, which can be accomplished either percutaneous transcatheter of an atrial septal occluder (ASO) device or open surgery. Closure using an occluder carries the risk of device embolization (DE). Case Presentation: This case series presents two patients who had dislodgement after ASD closure using ASO. The demographic data, comorbidities, surgical details, and follow-up results are all summarized. A 9-year-old girl and a 12-year-old boy admitted to our centre. The girl echocardiography evaluation revealed dislodgment of ASD occluder in a large secundum ASD, right upper PV blockage, and a high chance of pulmonary hypertension (PH). While the boy showed the occluder device that was misplaced and positioned in the right ventricle. A secundum ASD with a left to right shunt and moderate TR with a peak pressure gradient of 21.5mmHg were also found. During the procedure, we discovered that the girl had an occluder in the superior rim of ASD II 3x2 cm, which was dislodged towards the lower right PV, above the mitral valve, and the posterior occluder leaflet was removed by replacing a section of the rim. We discovered a secundum ASD with a dimension of 2x1cm on the boy The occluder was found behind the anterior cusp of the tricuspid valve. The retrieved occluder device appeared intact, and the tricuspid valve was injured, but no rupture. Conclusion: The occurrence of ASO migration is uncommon, necessitating further surgery for device removal, closure of the remaining defect, and ensure there is no cardiac erosion or rupture. Surgery can also alleviate symptoms including shortness of breath and palpitations

Outcomes of latent rheumatic heart disease: External validation of a simplified score in patients with and without secondary prophylaxis

BackgroundSecondary antibiotic prophylaxis reduces progression of latent rheumatic heart disease (RHD) but not all children benefit. Improved risk stratification could refine recommendations following positive screening. We aimed to evaluate the performance of a previously developed echocardiographic risk score to predict mid-term outcomes among children with latent RHD. MethodsWe included children who completed the GOAL, a randomized trial of secondary antibiotic prophylaxis among children with latent RHD in Uganda. Outcomes were determined by a 4-member adjudication panel. We applied the point-based score, consisting of 5 variables (mitral valve (MV) anterior leaflet thickening (3 points), MV excessive leaflet tip motion (3 points), MV regurgitation jet length ≥ 2 cm (6 points), aortic valve focal thickening (4 points) and any aortic regurgitation (5 points)), to panel results. Unfavorable outcome was defined as progression of diagnostic category (borderline to definite, mild definite to moderate/severe definite), worsening valve involvement or remaining with mild definite RHD. Results799 patients (625 borderline and 174 definite RHD) were included, with median follow-up of 24 months. At total 116 patients (14.5%) had unfavorable outcome per study criteria, 57.8% not under prophylaxis. The score was strongly associated with unfavorable outcome (HR = 1.26, 95% CI 1.16–1.37, p < 0.001). Unfavorable outcome rates in low (≤6 points), intermediate (7–9 points) and high-risk (≥10 points) children at follow-up were 11.8%, 30.4%, and 42.2%, (p < 0.001) respectively (C-statistic = 0.64 (95% CI 0.59–0.69)). ConclusionsThe simple risk score provided an accurate prediction of RHD status at 2-years, showing a good performance in a population with milder RHD phenotypes.

Transseptal Balloon-Assisted Translocation of the Mitral Anterior Leaflet (BATMAN) in Mitral Valve-in-Ring Implantation

Transseptal Balloon-Assisted Translocation of the Mitral Anterior Leaflet (BATMAN) in Mitral Valve-in-Ring Implantation

Surgical rescue mitral valve procedure post percutaneous transluminal mitral commissurotomy-a single-center observational study.

Percutaneous transluminal mitral commissurotomy (PTMC) has become the standard of care for severe mitral stenosis with favorable anatomy. Although the complications have reduced over the years, the need for emergency surgical rescue persists. This study evaluates the outcomes of surgical rescue performed within 24h of undergoing PTMC from 1 January 2013 to 31 December 2019. Out of 2259 PTMC patients, 22 patients (< 1%) required rescue mitral valve surgery. Out of 22 patients, 17 patients (77.27%) developed mitral regurgitation; five patients (22.7%) had cardiac tamponade. Mitral valve replacement was performed in 20 patients (90.9%), while two patients (9.1%) underwent mitral valve repair. Cardiac tamponade was secondary to injury of the left atrium (9.1%), left ventricle (4.5%), and right ventricle (9.1%). Concomitant tricuspid valve repair was done in three patients (13.6%). Intraoperatively, anterior mitral leaflet tear was seen in 68.2% while posterior mitral leaflet tear was noted in 9.1%. Postoperatively, three patients (13.6%) required prolonged ventilation, incidence of stroke was 4.5% (n = 1), and in-hospital mortality was 4.5% (n = 1). Intra-aortic balloon pump was used in three patients (13.6%), preoperatively. We conclude that post-PTMC complications are rare, but they require urgent surgical intervention.

Zero fluoroscopy catheter ablation of premature ventricular contractions: a multicenter experience.

Catheter ablation has become an established treatment option for premature ventricular complexes (PVCs). The use of fluoroscopy exposes patients and medical staff to potentially harmful stochastic and deterministic effects of ionizing radiations. We sought to analyze procedural outcomes in terms of safety and efficacy using a "zero fluoroscopy" approach for catheter ablation of PVCs. The present retrospective, multicenter, observational study included 131 patients having undergone catheter ablation of PVCs using "zero fluoroscopy" between 2019 and 2020 in four centers compared with another group who underwent the procedure with fluoroscopy. Median age was 51.0 ± 15.9 years old; males were 77 (58.8%). Among the study population, 26 (19.8%) had a cardiomyopathy. The most frequent PVC origin was right ventricular outflow tract (55%) followed by the left ventricle (16%), LVOT and cusps (13.7%), and aortomitral continuity (5.3%). Acute suppression of PVC was achieved in 127 patients (96.9%). At 12 months, a complete success was documented in 109 patients (83.2%), a reduction in PVC burden in 18 patients (13.7%), and a failure was recorded in four patients (3.1%). Only two minor complications occurred (femoral hematoma and arteriovenous fistula conservatively treated). The PVC ablation with a "zero" fluoroscopy approach appears to be a safe procedure with no major complications and good rates of success and recurrence in our multicenter experience.

Pseudoaneurysm of mitral-aortic intervalvular fibrosa with rupture: a case report

BackgroundMitral-aortic intervalvular fibrosa (MAIVF) is a fibrous region connecting the anterior mitral leaflet (AML) and aortic valve. Pseudoaneurysm of the MAIVF is a rare condition that has been reported as a sequela of infective endocarditis (IE) and surgical trauma. Here, we report a case of a ruptured pseudoaneurysm of the MAIVF, along with some literature reviews.Case presentationA 65-year-old man diagnosed with moderate aortic regurgitation five years previously had a fever of unknown origin. He suddenly developed headache and apraxia and was transported to our hospital. He was diagnosed with intracranial hemorrhage and admitted. One week after admission, echocardiography revealed aorto-mitral discontinuity and protrusion with severe regurgitant flow from left ventricular outflow tract to the left atrium. The AML was suspected to have ruptured. However, intraoperatively, the AML structure was preserved. A ruptured pseudoaneurysm of the MAIVF was also observed. Therefore, we successfully performed pseudoaneurysm repair using a bovine pericardial patch, aortic valve replacement, and mitral annuloplasty.ConclusionsP-MAIVF is a rare but potentially life-threatening complication of IE, for which timely diagnosis and prompt appropriate therapeutic intervention are required. In the present case, although neither obvious active IE nor history of previous IE could be identified, healed IE was considered based on the clinical course. The patient had intracranial hemorrhage (ICH) with well-controlled heart failure and underwent elective surgical repair more than one month after the onset of ICH, while the clinical course after the surgical procedure was uneventful.

Repair surgical techniques in degenerative cardiac valve disease

Background: Re-evaluation of reconstructive possibilities in the correction of degenerative mitral valve disease is of great clinical necessity nowadays. Material and methods: Analyzing the nature of the pathologies that determined the development mechanism of valve insufficiency, 136 cases of anterior cusp prolapse and 152 cases of posterior cusp prolapse were determined. Results: Cord rupture was established in 79 (58.9%) patients, cusp defects (”Cleft”) were appreciated in positions A1, A2, A3 – 15 cases (5.9%) and in P1, P2, P3 – in 92 (86.6%) cases. The surgical techniques performed were separated into: (1) resection – for the anterior and posterior cusps – 45 cases and accompanied by the slide – in 30 cases; (2) with Gore-Tex neo-chordal implantation – 115 cases, with cord transfer – 30; (3) Cusp enlargement with autologous pericardium – 5 cases, Alfieri procedure – 8. Implantation of a support ring required 130 (97.0%) patients. The correction of the associated valve disease required 125 patients (De Vega – 89.1%, ring – 8). Coronary bypass was required – 16 patients. There were no postoperative fatal cases. Conclusions: Based on the data obtained, reconstructive repair surgery can be can recommend for valves of degenerative, post-traumatic, ischemic, post-endocardial etiology as effective and sustainable techniques over time, being a superior alternative to replacement with prosthetic valves.

Aortic valve leaflets are asymmetric and correlated with the origin of coronary arteries.

Asymmetry of the aortic valve leaflets has been known since Leonardo Da Vinci, but the relationship between size and shape and origin of the coronary arteries has never been examined. Our aim was to evaluate this anatomy in a population of pediatric patients using a cross-sectional study design. Consecutive pediatric patients with trans-esophageal echocardiography (TEE), with or without trans-thoracic echocardiography (TTE), were included in our study. Exclusion criteria: (I) bicuspid aortic valve; (II) aortic valve stenosis; (III) hypoplasia of aortic valve annulus, or aortic root; (IV) truncal valve; (V) coronary artery atresia; (VI) previous surgery on aortic valve and/or coronary arteries. In pre-operative TTE and intra-operative TEE inter-commissural distance and length of aortic valve leaflets were measured in short axis view in the isovolumic phase of systole. Echocardiography investigations, anonymized and randomly coded, were independently reviewed by at least two readers. Echocardiography, angiography, cardiac computed tomography (CT) scan and magnetic resonance imaging (MRI), and operative notes were reviewed to identify origin of coronary arteries. Two hundred sixty-one pediatric patients were identified, 93 excluded per our criteria, leaving 168 patients, age 2.6±4.3 years, weight 12.87±17.34 kg, 128 (76%) with normal and 40 (24%) with abnormal coronary arteries. In TTE and TEE measurements the non-coronary leaflet had larger area (P<0.001), while the right and left had equal areas, but different shape, with the left leaflet longer (P<0.001) and narrower (P=0.005) than the right. With the major source of blood flow from the right coronary sinus, the non-coronary leaflet was still the longest. However, there was no statically significant difference between the size and shape previously observed between the right and left leaflets. Our study showed asymmetry of size and shape among aortic valve leaflets, and a relationship with coronary artery origin. The complex aortic root anatomy must be approximated to optimize function of any surgical repair. These findings also may prove useful in the pre-operative definition of coronary artery anatomy and in the recognition of coronary artery anomalies.

Mitral Annular Disjunction: Clinical Implications and Surgical Considerations.

Mitral annular disjunction is a cardiac structural abnormality characterized by the distinct separation between the top of the left ventricular myocardium and the mitral annulus supporting the posterior mitral leaflet occurring during systole. It has recently gained wide attention due to the increasing recognition of the link between mitral annular disjunction and arrhythmogenic mitral valve prolapse, particularly, with the increased risks of ventricular arrhythmias resulting in sudden cardiac death. This review has summarized the recent progress in the diagnostic modalities, clinical implications of mitral annular disjunction, and its specific surgical considerations.

Developing a Prediction Model for Persistent Systolic Anterior Motion After Mitral Valve Repair

BackgroundWe hypothesized that the distance between the anterior leaflet tip and the interventricular septum is a novel predictor for systolic anterior motion (SAM) after mitral valve repair. MethodsIn this case-control study, we included 139 patients who underwent mitral valve repair for degenerative mitral regurgitation between November 2014 and August 2022. We conducted multivariable logistic regression analysis to investigate the impact of the predictors associated with persistent SAM. A prediction model was developed and assessed for discrimination and calibration, and its clinical implications were evaluated by decision curve analysis. ResultsThe overall incidence of persistent SAM was 5.8% (8/139). The distance between the anterior leaflet tip and the interventricular septum exhibited the most significant association with persistent SAM. The prediction model constructed with this index combined with the body surface area yielded a concordance index of 0.934. The calibration curve displayed good visual alignment with the ideal 45-degree line. Decision curve analysis revealed that the net benefit offered by the model consistently outperformed that of the “all or none” intervention strategies. ConclusionsThe distance between the anterior leaflet tip and the interventricular septum, in conjunction with the body surface area, can be used to establish a prediction model for persistent SAM.

Mitral valve leaflet stiffness predicts residual mitral regurgitation after transcatheter edge-to-edge mitral valve repair.

Residual regurgitation after transcatheter edge-to-edge mitral valve repair (TMVR) is a predictor of poor prognosis in patients with functional mitral regurgitation (FMR). This study sought to identify the mitral valve (MV) parameters measured by three-dimensional transesophageal echocardiography (3D-TEE) and MV leaflet features that predict residual mitral regurgitation (MR) after TMVR in patients with FMR. Consecutive patients with FMR who underwent TMVR were classified into two groups based on the degree of residual MR just after TMVR:<2+ in the optimal MR reduction group and ≥ 2+ in the suboptimal MR reduction group. The two groups were compared with respect to 3D-TEE parameters and the MV leaflet features, including the following parameters: stiffness, defined as a leaflet that remains at a fixed angle even during diastole, and thickness, measured in both clear and rough zones. Thirty-four of 46 patients (74%) were classified as the optimal MR reduction group. Multivariable analysis showed that anterior mitral leaflet + posterior mitral leaflet length/anteroposterior annulus diameter (p=.044) and MV leaflet stiffness (p=.007) were independent predictors of residual MR. MV leaflet stiffness and the ratio of MV leaflet lengths to the annulus diameter may be good predictors of residual MR after TMVR in patients with FMR.

The Predictors and Outcomes of Functional Mitral Stenosis following Surgical Mitral Valve Repair: A Retrospective Analysis.

To optimize mitral valve repair outcomes, it is crucial to comprehend the predictors of functional mitral valve stenosis (FMS), to enhance preoperative assessments, and to adapt intraoperative treatment strategies. This study aimed to identify FMS risk factors, contributing valuable insights for refining surgical techniques. Among 228 selected patients, 215 underwent postoperative echocardiography follow-ups, and 36 met the FMS criteria based on a mean trans-mitral pressure gradient of >5 mmHg. Patients with FMS exhibited higher pulmonary systolic arterial pressure and increased late mortality during the follow-up. Univariable logistic regression analysis identified several risk factors for FMS, including end-stage renal disease, anterior leaflet lesion, concomitant aortic valve replacement, smaller ring size, ring type, and neochordae implantation. Conversely, resection alone and resection combined with neochordae implantation had protective effects against FMS. Multivariable logistic regression analysis revealed that smaller ring sizes and patch repair independently predicted FMS. When focusing on degenerative mitral regurgitation, the neochordae implantation without resection in leaflet repair, emerged as an independent predictor of FMS. Surgeons should weigh the substantial impact of surgical procedures on postoperative trans-mitral pressure gradients, emphasizing preoperative evaluation and techniques such as precise ring size assessment and effective leaflet management.

Surgical Treatment Methods for Tricuspid Valve Infective Endocarditis

Introduction: In recent years, there has been a significant increase in the incidence of tricuspid valve infective endocarditis (IE), which is associated with both the increased number of invasive examinations and procedures and the high rates of intravenous drug use. The initial treatment for tricuspid valve IE was surgical removal of the focus of infection and restoration of intracardiac hemodynamics.Reconstructive surgery aimed at preserving the valve is the preferred method of surgical treatment. If a valve-­preserving operation is not possible due to significant valvular apparatus destruction, implantation of artificial heart valves (both mechanical and biological) is the method of choice.Objective: To analyze the results of reconstructive valve-­preserving surgery and tricuspid valve replacement for tricuspid valve IE treatment.Materials and methods: In the Scientific Research Institute – Specialized Cardiac Surgery Clinical Hospital named after Academician B.A. Korolev (Nizhny Novgorod, Russian Federation) 110 patients underwent surgery for tricuspid valve IE. Primary surgery was performed in 97 patients, and 13 patients underwent repeated surgery. The patients were divided into 2 groups based on the chosen surgical method for correcting tricuspid valve disease. Group 1 included 62 patients who successfully underwent tricuspid valve replacement: mechanical prostheses in 10 patients and biological prostheses in 52 patients. Group 2 included 38 patients who underwent reconstructive valve­preserving surgery. All patients underwent De Vega annuloplasty. In 10 patients it was directly associated with bicuspidalization of the tricuspid valve and plastic surgery of intact leaflets. Two patients had suture annuloplasty of the tricuspid valve based on the modified technique. In 2 of 3 patients, an infected right atrial thrombus was removed. Three patients underwent removal of the left ventricular wall abscess and aortic valve replacement for critical stenosis. After translocation of the chords, triangular resection of the anterior leaflet was performed to separate the chord of the left side of the chest and the myxoma of the right and left chest.Results: In the early postoperative period, no valve­related complications were observed in group 1. The most common nonlethal complication was a third­-degree atrioventricular block. Multiple organ dysfunction syndrome occurred in 3 patients; cardiac tamponade was reported in 2 patients, and 1 patient had postoperative bleeding that required resternotomy for serous mediastinitis in the mid­term period and reosteosynthesis. At the hospital stage, 1 patient from group 1 died, whereas there were no deaths in group 2. In­-hospital mortality in the groups of operated patients was 0.9%.Functional ultrasound imaging findings in the postoperative period show that patients from group 1 had the peak gradient across the prosthetic tricuspid valve of 9.4 ± 1.8 mm Hg, while the mean gradient was 5.8 ± 1.75 mm Hg. There was a significant decrease in the estimated right ventricle pressure from 54.0 ± 16.2 to 35.0 ± 5.5 mm Hg. In group 2 tricuspid valve regurgitation was not observed in 27 patients, while mild and moderate regurgitation was reported in 8 and 3 patients, respectively. The peak gradient during the tricuspid valve reconstruction was 6.2 ± 1.7 mm Hg, while the mean gradient was 2.8 ± 0.75 mm Hg. The annulus fibrosus size during tricuspid valve annuloplasty averaged 30.8 ± 2.5 (28­33) mm. There was a decrease in the right ventricle pressure from 44.0 ± 18.4 to 32.0 ± 7.3 mm Hg. In the mid-­term follow­up, surviving patients were classified as NYHA classes I­-II. Of 110 patients discharged from the clinic, we were able to trace the fate of 69 patients, which accounted for 62.7%. In the long-­term period, 3 patients from group 1 died. Thus, long­term mortality in the general group was 2.72%.Conclusions: Reconstructive surgery has significant advantages over tricuspid valve replacement using various artificial heart valve models: lower rates of in-­hospital and long­-term mortality and specific complications, higher quality of life. Compliance with principles and methods of pathogenetic treatment of electrode­induced IE guarantees a success in the cohort of severe patients. The technique of reconstruction and restoration of tricuspid valve structures and functions in case of active tricuspid valve IE with detachment of the chords and destruction of the leaflets demonstrated high surgical efficiency.

Successful Transcatheter Closure of Iatrogenic Mitral Regurgitation After Aortic Valve Surgery

We present 2 cases of significant mitral regurgitation secondary to pericardial patch avulsion from the anterior mitral valve leaflet after aortic valve replacement with aortic annulus enlargement. Both cases were successfully managed by transcatheter repair with off-label implantation of occluder devices.

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

Abstract 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 a total of 12 homozygous PDGFRβ-E161K-/- mice, 11 heterozygous PDGFRβ-E161K+/- mice, and 7 WT mice were subjected to transthoracic echocardiography. In addition, histology was performed in all 30 mice to detect potential valvular defects. Results Stimulated HeLa cells expressing PDGFRβ-E162K 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 PDGFRβ-E161K+/- and PDGFRβ-E161K-/- compared to WT (WT: 1.97 mm; PDGFRβ-E161K+/-:2.13, p=0.031; PDGFRβ-E161K-/-: 2.42 mm, p&amp;lt;0.0001). Histological data in PDGFRβ-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; PDGFRβ-E161K-/-: 109.6 ɥm, p=0.040) and a larger leaflet area of the PMVL compared to WT (WT: 25280 ɥm²; PDGFRβ-E161K-/-: 44494 ɥm², p=0.020). Moreover, an altered organization of the extracellular matrix reminiscent of the myxomatous degeneration in MVP was observed. Conclusions The PDGFRβ-E162K variant is associated with familial MVP and alters the function of PDGFRβ. Mice harboring this mutation display mitral valve defects and can be used as a model for mitral valve disease.

Mitral leaflet retraction and left ventricular reverse remodeling in patients with treated dilated cardiomyopathy

Abstract Background Enlargement of the mitral leaflets (MLs) adaptive to mechanical stress caused by dilated left ventricle (LV) was recognized, but their changes after the stimuli withdrawn remained unexplored. Aims To observe morphological changes in the MLs along with LV reverse remodeling (LVRR) occurred after standard care. Methods Patients with recent-onset dilated cardiomyopathy (RODCM) were prospectively enrolled (n=82), as well as a group of age, sex and body surface area matched normal controls (NC) (n=50). Two-dimensional transthoracic echocardiography was performed at baseline and 6-month follow-up with special interests in the length of anterior and posterior mitral leaflet (AML and PML), mitral annular dimension (MAD) and tenting height (TH). LVRR was measured as a reduction in the LV end-diastolic volume (LVEDV) of ≥15%. Results At the 6-month follow-up, LVRR was achieved in 69.5% patients and there were 26.9% patients who reported ≥1 grade reduction in secondary mitral regurgitation that related to LVRR. The AML (28±3 vs. 26±3mm, p=0.004) and PML (19±4 vs. 17±3mm, p&amp;lt;0.001) were decreased, as well as the MAD (31±5 vs. 28±5mm, p=0.001) and TH (10±3 vs. 8±2mm, p&amp;lt;0.001), but all remained larger than that of the NC group (all p&amp;lt;0.05). When compared with the control group, the AML and PML of the RODCM group was 16.7% and 35.7% longer at baseline, which remained 8.3% and 21.2% longer at the follow-up, respectively. The change in the AML (△AML) or PML (△PML) correlated moderately to the change in the LVEDV (△LVEDV) (r=0.487, p&amp;lt;0.001; r=0.516, p &amp;lt;0.001, respectively) (Figure 1). When compared between the subgroups stratified by LVRR, both the AML and PML decreased in the patients who had LVRR (+) (AML, 28±3 vs. 26±3, p=0.001; PML, 20±4 vs. 16±3, p&amp;lt;0.001), but remained the same length in those with LVRR (-) (AML, 27±4 vs. 28±4, p=0.318; PML, 17±3 vs. 17±3, p=0.790). The comparison in the △AML and △PML between the two subgroups is shown in Figure 2. Conclusion The enlarged MLs could retract with different behavior in the AML and PML, accompanied by LV reverse remodeling. This study conducted in patients with RODCM who received standard therapy provided the other facet of mitral leaflet plasticity adaptive to mechanical stretch.correlation between △MLs and △LVEDVCompare △MLs between LVRR subgroups

Epidemiology and prognostic relevance of morphofunctional classification of secondary mitral regurgitation

Abstract Background Mitral regurgitation has traditionally been divided into organic and functional (FMR) due to its different etiology and prognosis. However, FMR is not a homogeneous entity, and may be secondary to annular dilation, ventricular dilation and dysfunction, or posterior leaflet restriction. Purpose Our aim is to assess the epidemiology of these FMR subtypes and their prognostic impact. Methods Patients with FMR from our center who underwent three-dimensional transesophageal echocardiography (3D-TEE) between 2016 and 2020 were retrospectively evaluated. Patients with at least moderate FMR, effective regurgitant orifice (ERO) by 3D-TEE &amp;gt;0.2 cm2 were selected. They were classified according to the predominant mechanism: type 1 or ventricular dysfunction, type 2 or posterior leaflet restriction, and type 3 or annular dilation. 3D-TEE and the closest transthoracic study variables, as well as baseline demographic and clinical characteristics and evolution events, were obtained and statistical analysis was performed according to FMR types. Results 112 patients were included (66.1% male, mean age 72.3 years). 54.5% had previous hospitalization for heart failure and 53.6% had a history of ischemic heart disease. The most frequently identified FMR mechanism was type 1 (61.6%), followed by type 3 (23.2%) and type 2 (15.2%). There were significant differences in epidemiological factors and echocardiographic parameters (Table) between groups. During follow-up, 43.8% died, received a heart transplant or LVAD and 44.6% had any hospitalization for heart failure. There were no significant differences between FMR types in relation to total mortality (p=0.28), mortality due to heart failure (p=0.13), total hospitalizations (p=0.73), or hospitalization for heart failure (p=0.12). Valvular intervention was performed in 54 patients (48.2%), 33 of them percutaneously with a clip, with no differences in FMR subtypes. Conclusions FMR is a heterogeneous entity and different morphotypes with different epidemiology and etiology can be identified. Despite the different mechanism, all subgroups presented a similar unfavorable prognosis and similar intervention rates.

Prognostic value of three-dimensional regurgitant orifice determination in functional mitral regurgitation

Abstract Background Functional mitral regurgitation (FMR) evaluation using effective regurgitant orifice (ERO) by echocardiography remains controversial. Given the morphology of regurgitant jets in FMR, determination of ERO using three-dimensional transesophageal echocardiography (3D-TEE) may be more accurate. However, a clear threshold for this parameter has not been defined. Purpose Our aim is to evaluate the prognostic value of 3D-ERO in FMR. Methods All patients with at least moderate FMR who underwent 3D-TEE in a tertiary center between 2016 and 2020 were retrospectively selected. Echocardiographic variables by transthoracic and transesophageal, as well as demographic and clinical history variables, were collected. A combined event of urgent hospital admission or death was considered. Variables statistically associated with the event were included in multivariate analysis. Results 112 patients (74 men (66.1%), mean age 72.3±10.9 years) were finally included. The most frequent etiology of FMR was ventricular dysfunction (61.6%), followed by annular dilation (23.2%) and posterior leaflet restriction (15.2%). The mean 3D-ERO was 0.53±0.25 cm2 and mean ejection fraction was 40.7±14.2%. At diagnosis, 49 patients (43.8%) were not receiving diuretics, 63 (56.2%) had atrial fibrillation/flutter, 60.3% permanent. FMR was treated in 54 patients (48.2%), 61,1% percutaneously. During a follow-up of 36 [14-54] months, 50 (44,6%) patients were urgently hospitalized (mean 1.9±2.8 admissions) and 49 (43,8%) died, received a heart transplant or LVAD. 3D-ERO was significantly associated with the occurrence of the event (0.55 vs 0.41; p=0.02). Additionally, 3D-ERO was associated with mitral intervention (0.58 vs 0.47 cm2; p=0.01) and had a trend towards death from any cause (0.56 vs 0.5 cm2; p=0.098). The prognostic capacity of 3D-ERO for the combined event was determined using an ROC curve (Figure). An AUC of 0.67 (95% CI 0.55-0.8; p=0.01) and an optimal cutoff value of 0.45 cm2 (sensitivity 0.62, specificity 0.73) were obtained. In univariate analysis, the combined event was also associated with age (73.9 vs. 65.6 years; p=0.01), diabetes (40 vs. 13.6%; p=0.02), chronic kidney disease (42.7 vs. 13.6%; p=0.01), ischemic heart disease (59.6 vs 31,8%, p=0.02) and daily furosemide dose (39.7 vs. 13.6 mg; p&amp;lt;0.01). In multivariate analysis of the event, age, daily furosemide dose, ischemic heart disease and 3D-ERO were included in the final predictive model (Table). Conclusions In patients with FMR, 3D-ERO was significantly associated with the occurrence of events during follow-up, with an optimal prognostic performance cutoff point of 0.45 cm2. Furthermore, it was an independent predictor of mitral intervention and included among the predictors of urgent hospital admission or death. Therefore, 3D-ERO may be useful in risk stratification of FMR.