Mitral Valve Repair Surgery Research Articles

Establishment and validation of a prediction model for the outcome of rheumatic mitral valve repair surgery based on transthoracic echocardiography

Abstract Background The outcome of mitral valve repair over replacement in degenerative diseases has been recognized, but the patient selection of mitral valve repair in rheumatic diseases are still controversial. At present, there is a lack of comprehensive evaluation methods for rheumatic mitral valve disease, which cannot guide the selection of patients before surgery. Purpose The aim of this study was to establish a comprehensive evaluation method and innovative indicators for rheumatic mitral valve disease using transthoracic echocardiography, and to establish a model for predicting the outcome of rheumatic mitral valve repair. Methods This prospective, multicenter, observational cohort study included 167 patients who underwent rheumatic mitral valve surgery in 4 centers from 2022 to 2023. Each enrolled patient underwent a comprehensive transthoracic echocardiography evaluation and measured 94 ultrasound indicators, mainly covering leaflets, annulus, subvalvular apparatus, and atrial and ventricular function. The main endpoint event was the failure of mitral valve repair (including switching to replacement after repair, and moderate to severe stenosis or regurgitation during follow-up after repair). Patients were randomly assigned to the modeling and validation groups at a ratio of 7:3. In the modeling group, LASSO regression was used for variable selection, and logistic regression was used for modeling. A nomogram was drawn and a webpage rating calculator was created. In the validation group, model comparisons were conducted using the C-statistic and Net Reclassification Index (NRI). Results 112 patients (67.1%) underwent mitral valve repair with satisfactory results, 47 patients (28.1%) ultimately underwent mitral valve replacement, and 8 patients (4.8%) found moderate to severe mitral stenosis or regurgitation during follow-up after repair. Three indicators, including mitral valve orifice area, leaflet calcification score, and anterior leaflet-annulus angle, were selected through LASSO regression. No collinearity was found between the three indicators, and they were ultimately included in the logistic regression model. The C statistics in the modeling group and validation group were 0.846 and 0.958, respectively, indicating that the constructed model has satisfactory predictive ability. Compared to the Wilkins score, the proportion of correctly classified items increased by 19.8%, significantly better than the Wilkins score. Finally, a nomogram was drawn based on the model, and a web rating calculator was created to guide clinical decision-making. Conclusion This study explored a comprehensive evaluation method and innovative indicators for rheumatic mitral valve disease by transthoracic echocardiography, established and validated a model for predicting the outcome of repair surgery, and had certain guiding significance for doctors to choose suitable patients for rheumatic mitral valve repair.Validation of the predictive modelNomogram

Differential hypoxemia during peripheral cardiopulmonary bypass.

Minimally invasive cardiac surgery (MICS) for mitral valve repair often uses cardiopulmonary bypass (CPB) through peripheral femoro-femoral cannulation. A rare complication of differential hypoxemia can cause upper body hypoxia. A 38-year-old man with Barlow Syndrome underwent MICS mitral valve repair with peripheral CPB. During the procedure, his right upper limb SpO2 dropped to 65% due to dislodgement of the venous cannula from the superior vena cava (SVC), causing inadequate right heart venous drainage, leading to differential hypoxemia. Repositioning the venous cannula to the SVC restored SpO2 to 100%, allowing the surgery to proceed without complications. Differential hypoxemia happens when deoxygenated blood from the left ventricle mixes with oxygenated CPB blood. A literature review found only one previous case of this complication on peripheral CPB for MICS. Unlike our case, Kanda et al. monitored cerebral hypoxia, underscoring the importance of cerebral oxygenation monitoring in future MICS procedures due to higher stroke risk compared to conventional sternotomy. We recommend cerebral oxygenation monitoring in future MICS to prevent neurological complications, and highlight the need for effective team communication in the cardiac operating theatre.

Characterization of atrial arrhythmias following mitral valve repair: Incidence and risk factors.

This study aims to investigate the occurrence, type and correlation of early and late atrial arrhythmias following mitral valve repair in patients with no preoperative history of atrial arrhythmias. Patients undergoing mitral valve (MV) repair for degenerative disease were included. Early and late postoperative electrocardiograms were evaluated for the incidence and type of atrial arrhythmia (atrial fibrillation [AF] or atrial tachycardia [AT]). The 192 patients were included. Early atrial arrhythmias occurred in 100/192 (52.1%) patients; AF in 61 (31.8%) patients, early AT in 15 (7.8%) and both in 24 (12.5%). In total 89% of patients were discharged in sinus rhythm. During a follow-up time of 7.3 years, 14 patients (7.3%) died and 49 (25.5%) patients developed late atrial arrhythmias. At 10 years, the cumulative incidence of any late atrial arrhythmia, with death as competing risk, was 64% (95% confidence interval [CI] = 55%-72%). On Fine-Gray model analysis, only early postoperative AF lasting >24 h was related to the development of late AF (hazard ratio 5.99, 95% CI = 1.78%-20.10%, p = .004). Early postoperative ATs were related to the development of late tachycardias, independent of their duration (<24 h hazard ratio 4.25, 95% CI = 1.89-9.57, p = .001 and >24 h hazard ratio 3.51, 95% CI = 1.65-7.46, p = .001). Early and late atrial arrhythmias were common after MV repair surgery. Only early postoperative AF lasting >24 h was a risk factor for the occurrence of late AF. Conversely, any postoperative AT was correlated to the development of late ATs.

Clinical implications of different methods to assess left atrial remodeling: A comparative study between echocardiography and cardiac magnetic resonance imaging for left atrial volume index quantification

BackgroundLeft atrial volume index (LAVI) serves as a crucial marker for assessing left atrial (LA) remodeling, particularly in patients with mitral valve regurgitation (MR). Recent guidelines recommend a LAVI exceeding 60 mL/m2 as Class IIa recommendation for mitral valve repair surgery in asymptomatic MR patients with preserved left ventricular function. Traditionally, echocardiography is the standard for assessing LAVI in MR patients. However, cardiac magnetic resonance imaging (CMR) is increasingly recognized for its more precise measurements of cardiac dimensions and volumes. But still, literature remains scarce on comparing the efficacy of both modalities in assessing LAVI measurements. MethodsThis retrospective study included 168 MR patients undergoing both echocardiography and CMR assessments within a six-month period. LAVI measurements were compared using Pearson correlation and Bland-Altman plots. Patients were stratified based on MR grades, and clinical implications were assessed. ResultsMean LAVI differed significantly between echocardiography and CMR (47.1 ± 20.8 mL/m2 versus 70 ± 20.3 mL/m2, p < 0.001, respectively). CMR consistently yielded higher LAVI measurements compared to echocardiography, with a mean difference of approximately 20 mL/m2. CMR measurements resulted in an increased incidence of patients meeting the class IIa LAVI criterion (LAVI >60 mL/m2) by 37%. Variations in LAVI did not differ across MR grades. ConclusionEchocardiography systematically underestimates LAVI compared to CMR in MR patients. While current guidelines rely on echocardiography, CMR's precision suggests the need for CMR-specific LAVI cutoff values to guide clinical management effectively. Establishing such values could refine patient stratification and timing of surgery, potentially improving clinical outcomes for MR patients.

Biomarkers of inflammation and coagulation after minimally invasive mitral valve surgery: a prospective comparison to conventional surgery

STRUCTURED ABSTRACT Objectives Minimally invasive cardiac surgery techniques are increasingly used but have longer cardiopulmonary bypass time, which may increase inflammatory response and negatively affect coagulation. Our aim was to compare biomarkers of inflammation and coagulation as well as transfusion rates after minimally invasive mitral valve repair and mitral valve surgery using conventional sternotomy. Design A prospective non-randomized study was performed enrolling 71 patients undergoing mitral valve surgery (35 right mini-thoracotomy and 36 conventional sternotomy procedures). Blood samples were collected pre- and postoperatively to assess inflammatory response. Thromboelastometry (ROTEM) was performed to assess coagulation, and transfusion rates were monitored. Results The minimally invasive group had longer cardiopulmonary bypass times compared to the sternotomy group: 127 min ([115–146] vs 79 min [65–112], p < 0.001) and were cooled to a lower temperature during cardiopulmonary bypass, 34 °C vs 36 °C (p = 0.04). IL-6 was lower in the minimally invasive group compared to the conventional sternotomy group when measured at the end of the surgical procedure, (38 [23–69] vs 61[41–139], p = 0.008), but no differences were found at postoperative day 1 or postoperative day 3. The transfusion rate was lower in the minimally invasive group (14%) compared to full sternotomy (35%, p = 0.04) and the chest tube output was reduced, (395 ml [190-705] vs 570 ml [400–1040], p = 0.04). Conclusions Our data showed that despite the longer use of extra corporal circulation during surgery, minimally invasive mitral valve repair is associated with reduced inflammatory response, lower rates of transfusion, and reduced chest tube output.

Mechanical Analysis of the Connection Structure of a Double-Layered Valve Stent within an Annuloplasty Ring

Background: In this study, to address the failure of mitral valve repair surgery, a novel valve-in-ring model for an artificial mitral valve annuloplasty ring and a new double-layer mitral valve were established. A suitable number and length of ventricular fixation struts within the annuloplasty ring, as well as the implantation depth, result in variations in stress and strain for the inner and outer stent layers. Methods: The compression and self-expansion model of the stent was established via finite element analysis. The changes in stress and strain were analyzed by setting the length and number of the ventricular fixed struts and implantation depth. Results: When only affected by factors such as blood pressure, the maximum stresses of stent structures with three and six ventricular fixed struts are 476 and 222 MPa, respectively, in the right posterior annular region. At implantation depths of 0, 0.5, 1, and 2 mm, the maximum stresses are located in the left posterior annular region of the outer stent and are 740, 697, 709, and 742 MPa, respectively, and the maximum displacements of the inner stent are all in the right posterior ventricular fixed strut region of the posterior annulus and are 3.71, 3.10, 2.48, and 1.87 mm, respectively. In the three and six ventricular fixed strut stents, when the ventricular fixed strut length is 3, 4, and 5 mm, the maximum stresses are 570, 557, and 621 MPa and 674, 666, 644 MPa, respectively. Conclusions: Appropriately increasing the number of ventricular fixed struts can effectively reduce damage to the stent inside the body, and the damage to the stent is relatively consistent across different implantation depths; however, the right side of the stent's posterior annulus is particularly susceptible to damage. However, if the implantation depth is lower, the impact on the inner stent will be more significant. As the number of ventricular fixed struts increases, the strut length variation has a relatively stable impact on stent damage.

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.

Large Animal Translational Validation of 3 Mitral Valve Repair Operations for Mitral Regurgitation Using a Mitral Valve Prolapse Model: A Comprehensive In Vivo Biomechanical Engineering Analysis.

Various mitral repair techniques have been described. Though these repair techniques can be highly effective when performed correctly in suitable patients, limited quantitative biomechanical data are available. Validation and thorough biomechanical evaluation of these repair techniques from translational large animal in vivo studies in a standardized, translatable fashion are lacking. We sought to evaluate and validate biomechanical differences among different mitral repair techniques and further optimize repair operations using a large animal mitral valve prolapse model. Male Dorset sheep (n=20) had P2 chordae severed to create the mitral valve prolapse model. Fiber Bragg grating force sensors were implanted to measure chordal forces. Ten sheep underwent 3 randomized, paired mitral valve repair operations: neochord repair, nonresectional leaflet remodeling, and triangular resection. The other 10 sheep underwent neochord repair with 2, 4, and 6 neochordae. Data were collected at baseline, mitral valve prolapse, and after each repair. All mitral repair techniques successfully eliminated regurgitation. Compared with mitral valve prolapse (0.54±0.18 N), repair using neochord (0.37±0.20 N; P=0.02) and remodeling techniques (0.30±0.15 N; P=0.001) reduced secondary chordae peak force. Neochord repair further decreased primary chordae peak force (0.21±0.14 N) to baseline levels (0.20±0.17 N; P=0.83), and was associated with lower primary chordae peak force compared with the remodeling (0.34±0.18 N; P=0.02) and triangular resectional techniques (0.36±0.27 N; P=0.03). Specifically, repair using 2 neochordae resulted in higher peak primary chordal forces (0.28±0.21 N) compared with those using 4 (0.22±0.16 N; P=0.02) or 6 neochordae (0.19±0.16 N; P=0.002). No difference in peak primary chordal forces was observed between 4 and 6 neochordae (P=0.05). Peak forces on the neochordae were the lowest using 6 neochordae (0.09±0.11 N) compared with those of 4 neochordae (0.15±0.14 N; P=0.01) and 2 neochordae (0.29±0.18 N; P=0.001). Significant biomechanical differences were observed underlying different mitral repair techniques in a translational large animal model. Neochord repair was associated with the lowest primary chordae peak force compared to the remodeling and triangular resectional techniques. Additionally, neochord repair using at least 4 neochordae was associated with lower chordal forces on the primary chordae and the neochordae. This study provided key insights about mitral valve repair optimization and may further improve repair durability.

Relationship between fragmented QRS complex and early left ventricular dysfunction after mitral valve repair

BackgroundPreoperative left ventricular (LV) ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair (MVR). Fragmented QRS (fQRS) evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis.In the present study, we aimed to evaluate the relationship between fQRS in preoperative 12‑lead electrocardiography (ECG) and postoperative LV dysfunction that develop after MVR in patients with severe primary mitral regurgitation (MR) due to mitral valve prolapse (MVP). MethodsFrom 2019 to 2022, 49 patients who had undergone successful MVR surgery for severeMR caused by MVP were enrolled in the study. The preoperative and postoperative echocardiographic data were collected retrospectively. We analyzed the demographic, echocardiographic, operative and postoperative parameters to assess the relationship between fQRS and early postoperative LV dysfunction, defined as an LVEF<60%. ResultsPreLVEF of all patients were ≥ %65. A total of 22 patients had fQRS (44.9%) and postoperative LV dysfunction was found to be 36.7%. A significantly higher rate of fQRS was observed in the group with postoperative LV dysfunction compared to the group without (12 (66.7%) vs 10 (32.3%), p: 0.036). In multivariate analysis for fQRS, PreESD, preoperative pulmonary artery systolic pressure (PrePASP), preoperative atrial fibrillation (PreAF), and male gender, only fQRS was found to be a significant predictor of postoperative LV dysfunction (p: 0.003, OR: 4.28, 95% CI (1.15–15.96). ConclusionfQRS was found to be a predictor of postoperative LV dysfunction in the early period after MVR. fQRS may be a readily available and cost-effective test that can be used in clinical practice to predict postoperative LV dysfunction in patients undergoing MVR.

Clinical Outcome of Rheumatic Mitral Valve Repair and Replacement Surgery in Indonesia; A Comparison with Non-Rheumatic Aetiology.

Mitral valve repair (MVr) has been shown to achieve better outcomes than mitral valve replacement (MVR) in degenerative aetiology. However, that cannot be applied in rheumatic mitral valve disease. Therefore, this study aims to evaluate early and late clinical outcomes and mid-term survival in RHD compared to the non-RHD group and whether mitral valve repair is a better surgical approach in RHD patients. Patients who underwent mitral valve surgery with or without coronary artery bypass grafting were included in this study. All patients were divided into the RHD and non-RHD group by the type of mitral surgery performed. Early and late outcomes were evaluated, and mid-term cumulative survival was reported. A total of 1382 patients post MV surgeries were included. The 30-day mortality was significantly higher in the RHD group compared to the non-RHD group (8.7% vs. 4.4%, p = 0.003). There was no difference in 30-day mortality between repair and replacement in each respective group. During follow-up (12-54 months), all-cause mortality between RHD and non-RHD groups (16.7% vs. 16.2%) was not different. In the RHD group, the survival of MVr was 85.6% (95% CI 82.0%-88.5%), and MVR was 78.3% (95% CI 75.8%-80.6%), p-value log rank 0.26 However, in the non-RHD group, patients who underwent MVr had better survival than MVR, with cumulative survival of 81.7% (95% CI 72.3%-88.2%) vs. 71.1% (95% CI 56.3%-81.7%) p-value log rank 0.007. Early mortality rate in rheumatic mitral valve surgery was higher than in non-rheumatic valve surgery. Although in rheumatic MV disease MV repair did not show a significant survival advantage over MV replacement, a trend towards more favourable survival in the repair group was observed.

Pushing boundaries in cardiac surgery: minimally invasive mitral valve repair combined with tricuspid valve repair and/or other concomitant procedures.

Minimally invasive mitral valve repair/replacement has emerged as a widely accepted surgical approach for managing mitral valve disorders. Continuous technological progress has contributed to the refinement of this procedure, leading to improved safety, decreased surgical trauma, and faster recovery times. Despite these advancements, there remains a scarcity of data concerning minimally invasive complex mitral valve repair surgeries when combined with additional procedures. Between November 2008 and December 2022, 153 patients underwent an operation using a minimally invasive technique. All patients underwent mitral valve surgery for severe mitral valve insufficiency/stenosis in combination with at least one additional procedure for tricuspid valve repair (n = 52, 34%), patent foramen ovale or atrial septal defect closure (n = 34, 22.2%), left atrial appendage occlusion (n = 25, 16.3%), or electrophysiological procedure (n = 101, 66.0%). Two concomitant procedures were conducted in 98 patients (64.1%), three concomitant procedures in 49 patients (32%), and four concomitant procedures in 6 patients (3.9%). Surgical success was achieved in 99.3% of the patients (n = 152), one patient required a revision of the mitral valve repair on the first postoperative day due to systolic anterior motion phenomenon. Mitral valve repair was performed in 136 patients (88.9%), while 15 patients (9.8%) received a mitral valve replacement as per a preoperative decision due to severe mitral valve stenosis, and two patients (1.3%) underwent other mitral valve procedures. Therapeutic success in treating atrial fibrillation was achieved in 86 patients (85.1%) of the 101 who received an additional maze-procedure. The 30-day mortality rate was 0.7%, with one patient succumbing to respiratory failure. Neurological complications occurred in 7 patients (4.6%). Freedom from reoperation was calculated as 98% at 5-year follow-up and 96.5% at 10-year follow-up. Minimally invasive mitral valve surgery, even when performed alongside concomitant procedures, stands out as a reproducible and safe technique with outstanding outcomes. It is imperative to advance towards the next frontier in minimally invasive surgery, encouraging experienced surgeons to undertake more complex procedures using minimally invasive approaches. These results help envision extending the boundaries of minimally invasive surgery by performing complex mitral valve procedures and associated interventions entirely through endoscopic means in suitable patients.

Trends in Isolated Mitral Valve Repair or Replacement Surgery in Australia: A Statewide Cohort Linkage Study

Global trends in mitral valve surgery (MVSx) suggest increasing repair compared with replacement, especially in the United States and European countries. The relative use, and outcomes of, MV repair and replacement in Australia are unknown. New South Wales residents who underwent isolated MVSx between 2001 and 2017 were identified from the Admitted-Patient-Data-Collection database. Mortality outcomes were tracked to 31 Dec 2018 and adjusted based on age, sex, urgency of operation, and comorbidity status. The study cohort comprised 5,693 patients: 2020 (35%) underwent repair (MVr), 1,656 (29%) underwent mechanical replacement (mech.MVR), and 2017 (35%) underwent bioprosthetic replacement (bio.MVR). Respective median ages [interquartile range] were 67 yo [59-75 yo], 64 yo [55-71 yo], and 75 yo [68-80 yo] (p<0.001 across groups). Between 2001 and 2017, total MVSx increased steadily with population growth. Whereas the relative use of MVr remained static (34% to 38%), that for bio.MVR (22% to 50%) and mech.MVR (45% to 13%) changed significantly. MVr had the best outcome with 1.2% in-hospital, 2.5% 1-year, and 21.6% total cumulative mortality during a median follow-up of 6.5 years. Compared to MVr, the adjusted hazard ratio (aHR) for mech.MVR and bio.MVR for long-term mortality were 1.41 (95% confidence interval [CI]=1.24-1.61) and 1.73 (95% CI=1.53-1.95), respectively. Heart failure and sepsis were the main cardiovascular and noncardiovascular causes of death in all groups. In this statewide Australian cohort examined over 17 years, MVr is potentially underutilised despite having superior outcomes to MVR. Access to quality dataset which provides the indication for MVSx and quantitative clinical factors is critical to further improve MVr coverage and outcome MVSx.

Early mitral valve repair surgery versus active surveillance in patients with asymptomatic severe primary mitral regurgitation; insights from the Dutch AMR registry

Abstract Background Management of asymptomatic patients with severe mitral regurgitation (MR) and preserved left ventricular function is still a challenging clinical entity. According to international guidelines, early mitral valve repair (MVR) surgery and active surveillance with facilitated surgery are both possible treatment strategies. Conflicting evidence is available on the number of patients that reach an indication for facilitated surgery during follow-up in the active surveillance strategy group [1, 2]. In the multicenter Dutch AMR registry, asymptomatic MR patients were allocated to either strategy according to the heart team decision [3]. In this registry there was a low threshold to perform additional testing (i.e. cardiac magnetic resonance imaging, holter monitoring and/or cardiopulmonary exercise testing). Purpose To prospectively assess the percentage of MR patients undergoing facilitated surgery during a long-term active surveillance strategy. Methods Since 2013, 99 patients with severe primary MR were included in the Dutch AMR Registry in 5 medical centers. Enrollment for early surgery or active surveillance was based on ESC guidelines and heart team decision. During long term follow-up, we assessed primary endpoints for both groups; occurrence of atrial fibrillation, cerebrovascular accident, heart failure, MVR surgery and cardiovascular/non-cardiovascular death. In particular, we assessed the number and timing of patients that underwent facilitated surgery in the active surveillance group. Results In total, 71 patients were allocated to the active surveillance and 28 to the early surgery group. 39 Patients in the active surveillance group reached a primary endpoint including 3 deaths (2 cardiovascular and 1 non-cardiovascular) (Figure 1). In the early surgery group, 4 patients reached a primary endpoint including 2 cardiovascular deaths. Over a mean follow-up time of 4.4 years, 36 patients (51%) of the active surveillance population underwent facilitated surgery due to either symptomatic or asymptomatic triggers (Table 1). Conclusions In the Dutch AMR registry, 51% of MR patients under active surveillance needed facilitated surgery within 4.4 years. Approximately half of these patients were still asymptomatic when developing an indication for surgery. Cardiovascular mortality rates were similar between the two treatment strategies. This result shows that active surveillance can be safely accomplished in asymptomatic severe MR patients. The Dutch AMR registry will further elucidate 1) whether MR patients can be stratified at baseline to either strategy based on additional testing and 2) whether facilitated surgery is non-inferior to early surgery in terms of surgical outcome, quality of life and long-term survival. For now, the current results support an active surveillance strategy in selected asymptomatic MR patients based on guidelines since half of patients are still free of symptoms without guideline indications for surgery.Figure 1Table 1

Spatial transcriptomic analysis identifies a border zone with localized expression of brain natriuretic peptide in the inferobasal region of the left ventricle in patients with mitral valve prolapse

Abstract Background/Introduction Mitral valve prolapse (MVP) is a common cause of mitral regurgitation (MR), adverse left ventricular (LV) remodeling and arrhythmias. MVP induces mechanical stretch to the inferobasal (IB) myocardium and papillary muscles. The underlying regional and molecular pathology of MVP-induced LV remodeling remains incompletely understood. Purpose The aim was to characterize the molecular effects of mechanical stretch by comparing the regional gene expression of the IB region of LV with the interventricular septum in patients with MVP. Methods Myocardial biopsies were obtained from the IB LV (i.e. between papillary muscles) and the interventricular septum during mitral valve repair surgery for MVP-induced primary MR. The degree of cardiac fibrosis was detected and quantified by histology. We used spatial transcriptomics (ST) that - in contrast to traditional analyses of tissue homogenates - allows regional expressional analysis. Results Automated clustering of ST results correlated with histological staining of fibrosis in the IB and septal regions (R=0.97, P&amp;lt;0.0001), demonstrating good automated identification of fibrotic regions. The extent of fibrosis was similar between the inferobasal region and the septal control in the respective patients with MVP as determined by histological analysis and ST. The localized fibrotic areas of the inferobasal region showed decreased expression of cardiac myocytegenes such as RYR2, TNNI3, TNNC1 or TPM1, and increased expression of fibrous and EndMT markers such as COL3A1, BGN, SM22 or FN1. In the IB region, we identified a transition zone between healthy myocardium and fibrous tissue. This transition zone showed increased expression of the NPPB gene encoding brain natriuretic peptide (BNP), whereas NPPB was not increased in the septal region of the same patients. The upregulation of NPPB (6.4-fold, P=0.004) in the inferobasal region compared to the septal control was confirmed by qPCR in biopsies from patients with MVP. The identified transition zones were characterized by increased expression of genes such as IGFBP2 and LTBP2, which have been described to be associated with adverse LV remodeling in heart failure. Interestingly, the serum NT-proBNP levels (mean 276.8 ± 121.6 pg/ml) of the patients correlated with NPPB levels from the inferobasal region (R=0.76, P=0.01, N=9), whereas no correlation was found with NPPB levels from the septal control regions (R=0.17, P=0.65) of the same patients. Conclusions ST analysis in MVP identifies a transition zone of the inferobasal region of LV which is exposed to high mechanical stretch. This transition zone - but not the inferobasal fibrotic area nor the LV septum - is characterized by a specific increase in NBBP expression that correlates with increased NT-ProBNP serum concentrations. These special sequencing results indicate that mechanical stretch induces highly localized myocardial pathologies with systemic consequences.

Impact of Bariatric Surgery on Mortality of Mitral Valve Surgery: A National Analysis.

Obesity is a common comorbidity of cardiac surgery patients. The goal of this study is to determine if a lower weight achieved through bariatric surgery has any association with mitral valve (MV) replacement or repair surgery mortality. This study used a retrospective analysis of the National Inpatient Sample dataset from 2012 to 2020. Adult patients who underwent MV surgery with normal weight following bariatric surgery (n = 1,125) and patients with obesity (n = 48,555) were compared. The primary outcome was in-hospital mortality. This study included 49,680 patients. The median age was 64 (55 to 71) years, and the majority were female (55%). Bariatric surgery was found to significantly decrease the odds of mortality, even after adjusting for important covariates, indicating a reduction of mortality risk by 54% (adjusted odds ratio = 0.46, p = 0.024). Other significant protective factors include isolated and elective surgery. Significant risk factors were older age, female sex, and diabetes mellitus. Patients who were obese demonstrated longer lengths of stay (LOS), greater transfers to other facilities, and higher hospital costs. In patients receiving MV surgery, bariatric surgery demonstrated significant survival benefits during hospitalization, in addition to reducing LOS and cost. Our data support prior evidence of bariatric surgery improving cardiovascular outcomes. Therefore, bariatric surgery may be a meaningful method of weight loss to improve surgical patient outcomes in patients with obesity. However, longer-term data are needed.

Case Report: Optical coherence tomography to guide PCI of iatrogenic injury of the circumflex artery after minimally invasive mitral valve repair

We present a case of a 42-year-old man who suffered an iatrogenic injury to his left circumflex (Cx) coronary artery after mitral valve (MV) repair surgery. After the patient suffered from myocardial infarction without ST-segment elevation following minimally invasive MV surgery, we performed repeated coronary angiography and optical coherence tomography (OCT), which revealed severe coronary stenosis of the dominant Cx caused by intramural hematoma. In addition, we proceeded with percutaneous coronary intervention and stent implantation.

Closed-chest robotic repair of mitral prolapse. Surgical technique and early results.

Robotic mitral repair is generally performed with four intercostal trocars and a minithoracotomy. We describe our technique and results with a totally-thoracoscopic closed chest approach using a 12 mm valveless trocar as "working port", without a minithoracotomy. We compared our results with this technique with a control group of robotic mitral repairs performed earlier with a minithoracotomy. Review of all patients with degenerative mitral valve disease who underwent robotic mitral valve repair surgery since December 2019 (n = 110). Patients with concomitant procedures (n = 8) were excluded. The remaining 102 patients were divided in two groups, depending on the approach used, minithoracotomy (n = 63) and totally thoracoscopic (n = 39). There were no significant differences between groups regarding preoperative characteristics. All procedures were completed robotically as planned, and repair rate was 100%. The minithoracotomy group showed a higher percentage of leaflet resections (17.9% vs. 38.7%; p = 0.03). All surgical times were significatively reduced in the totally thoracoscopic group: Cardiopulmonary bypass (97 vs. 115 min, p = 0.0008), ischemic time (67 vs. 80 min, p = 0.0013) and total surgical time (185 vs. 225 min; p < 0.00001). There were no differences in ICU length of stay (1 day, p = 0.07) but hospital length of stay was shorter in the totally thoracoscopic group (4 days; p = 0.0001). Postoperative complications were similar between groups. MR at discharge was mild or less in all cases. Robotic mitral repair for degenerative disease can be safely performed as a closed-chest procedure, using a 12 mm trocar as "working port" and avoiding the need for a minithoracotomy. This approach does not seem to negatively affect the quality of the procedure by any measure, providing similar excellent clinical outcomes and repair rate. All surgical times were shorter in the closed-chest group.

Echocardiographic diagnosis of rupture of mitral valve papillary muscle

ObjectiveTo explore the value of echocardiography in diagnosing papillary muscle rupture (PMR) of the mitral valve, and summarize the characteristic echocardiographic features of different types. MethodsEchocardiograms of 13 PMR patients confirmed by surgery in Wuhan Union Hospital between January 2009 and December 2022 were retrospectively analyzed and their preoperative transthoracic echocardiography (TTE) was compared with surgical findings. ResultsA total of 9020 patients underwent mitral valve repair or replacement surgery during the study period including 13 (0.14%) for PMR. Of the 13 PMRs, 8 cases were partial PMR(P-PMR), 5 cases were complete PMR(C-PMR); 3 cases were anterolateral PMR, and 10 were posteromedial PMR. The diagnostic accuracy, sensitivity, and specificity of the preoperative TTE were 99.9%, 53.8% and 99.9% respectively. Echocardiographic features of 10 patients (5-C-PMR and 5 P-PMR) with detailed TTE and intraoperative transesophageal echocardiography (TEE) data included: both anterior and posterior leaflets prolapse (C-PMR 60% vs P-PMR 60%); flail leaflet (C-PMR100% vs P-PMR 40%); All C-PMRs and P-PMRs have severe, eccentric and lateral regurgitation; flail attachment (chordae tendinae and ruptured PM) at the tip of prolapsed leaflet (C-PMR100% vs P-PMR 60%); high-echo masses resembled “champagne glasses” in 100% of the C-PMR; high-echo masses resembled “lotus-seedpod” in 60% and “dumbbell-shaped” torn PM in remaining 40% of the P-PMR. ConclusionsDifferent PMR subtypes have different echocardiographic characteristics. Combining TTE and TEE can accurately identify the typical features of PMR such as ipsilateral hemipetal leaflet prolapse, high-echoic mass at the tip of the leaflet, massive eccentricity and lateral regurgitation.

Mid-term results of endoscopic mitral valve repair and insights in surgical techniques for isolated posterior prolapse.

The adoption of minimally invasive techniques to perform mitral valve repair surgery is increasing. This is enhanced by the compelling evidence of satisfactory short-term results and lower major morbidity. We analyzed mid-term follow-up results of our experience, and further compared two techniques: isolated leaflet resection and neochord implantation for posterior leaflet prolapse. Data for all consecutive endoscopic mitral valve repairs via video-assisted right anterior mini-thoracotomy were analyzed between December 2012 and September 2021. The early and mid-term follow-up results were ascertained. The main outcome was the incidence of mortality and the recurrence of significant mitral regurgitation during follow-up which were summarized by the Kaplan-Meier estimator and compared between treatment arms using the stratified log-rank test. Secondary outcomes were the early-postoperative results including 30-days mortality and the occurrence of major complications. A total of 309 patients were included. Along with ring annuloplasty, 136 (44.4%) patients received posterior leaflet resection (122 isolated) whereas 97 (31.1%) underwent posterior leaflet chords implantation (88 isolated). Forty-nine patients had annuloplasty alone. In-hospital mortality was 1.0%. Mean follow-up was 28.8 ± 22.0 months (maximum 8.3 years). Kaplan-Meier survival rate at 5 years was 97.3 ± 1.0%, mitral regurgitation ([Formula: see text]3+) or valve reoperation free-survival at 5 years was estimated as 94.5 ± 2.3%. Subgroup time-to-event analysis for the indexed outcomes showed no statistical significance between the techniques. Endoscopic mitral valve repair is safe and associated with excellent short- and mid-term outcomes. No differences were found between leaflet resection and gore-tex chords implantation for posterior leaflet prolapse.

Abstract P2100: Highly Localized Myocardial Expression Of Brain Natriuretic Peptide In Patients With Mitral Valve Prolapse

Mitral valve prolapse (MVP) is a common cause of mitral regurgitation (MR), adverse left ventricular (LV) remodeling and arrhythmias. MVP induces mechanical stretch to the inferobasal (INF) myocardium and papillary muscles. The underlying regional and molecular pathology of MVP-induced LV remodeling remains incompletely understood. The aim was to characterize the molecular effects of mechanical stretch by comparing the regional gene expression of the INF region of LV in patients with MVP. Biopsies were obtained from the INF LV and the interventricular septum during mitral valve repair surgery for MVP-induced primary MR. Spatial transcriptome sequencing results correlated with histological staining of fibrosis in the INF and septal regions (R=0.97, P&lt;0.0001). The extent of fibrosis was similar between the INF region and the septal control in the respective patients with MVP. The localized fibrotic areas of the INF region showed decreased expression of cardiac myocyte genes and increased expression of fibrous and EndMT markers. In the INF region, we identified a transition zone between healthy myocardium and fibrous tissue. This transition zone showed increased expression of the NPPB gene encoding brain natriuretic peptide (BNP), whereas NPPB was not increased in the septal region of the same patients, and was confirmed by qPCR (NPPB +6.4-fold, N=11, P=0.004). The INF border zone is characterized by increase expression of NPPB, IGFBP2 and MFGE8, which have been described to be associated with adverse LV remodeling in heart failure. The serum NT-proBNP levels (mean 276.8 ± 121.6 pg/ml) of the patients correlated with NPPB levels from the INF region (R=0.76, P=0.01, N=9), whereas no correlation was found with NPPB levels from the septal control regions (R=0.17, P=0.65) of the same patients. In conclusion, spatial transcriptome analysis in MVP patients identifies a transition zone of the INF region of LV which is exposed to high mechanical stretch. This localized transition zone has a specific gene expression profile, e.g. with increased NBBP expression that correlates with increased NT-ProBNP serum concentrations. Our results indicate that mechanical stretch induces highly localized myocardial pathologies with systemic consequences.