Degenerative Mitral Valve Disease Research Articles

Phosphoproteomics analysis of serum from dogs affected with pulmonary hypertension secondary to degenerative mitral valve disease.

Pulmonary hypertension (PH), a common complication in dogs affected by degenerative mitral valve disease (DMVD), is a progressive disorder characterized by increased pulmonary arterial pressure (PAP) and pulmonary vascular remodeling. Phosphorylation of proteins, impacting vascular function and cell proliferation, might play a role in the development and progression of PH. Unlike gene or protein studies, phosphoproteomic focuses on active proteins that function as end-target proteins within signaling cascades. Studying phosphorylated proteins can reveal active contributors to PH development. Early diagnosis of PH is crucial for effective management and improved clinical outcomes. This study aimed to identify potential serum biomarkers for diagnosing PH in dogs affected with DMVD using a phosphoproteomic approach. Serum samples were collected from healthy control dogs (n = 28), dogs with DMVD (n = 24), and dogs with DMVD and PH (n = 29). Phosphoproteins were enriched from the serum samples and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Data analysis was performed to identify uniquely expressed phosphoproteins in each group and differentially expressed phosphoproteins among groups. Phosphoproteomic analysis revealed nine uniquely expressed phosphoproteins in the serum of dogs in the DMVD+PH group and 15 differentially upregulated phosphoproteins in the DMVD+PH group compared to the DMVD group. The phosphoproteins previously implicated in PH and associated with pulmonary arterial remodeling, including small nuclear ribonucleoprotein G (SNRPG), alpha-2-macroglobulin (A2M), zinc finger and BTB domain containing 42 (ZBTB42), hemopexin (HPX), serotransferrin (TRF) and complement C3 (C3), were focused on. Their unique expression and differential upregulation in the serum of DMVD dogs with PH suggest their potential as biomarkers for PH diagnosis. In conclusion, this phosphoproteomic study identified uniquely expressed and differentially upregulated phosphoproteins in the serum of DMVD dogs with PH. Further studies are warranted to validate the diagnostic utility of these phosphoproteins.

Trends in the Management of Anterior Mitral Leaflet Regurgitation

The overall prevalence of mitral valve replacement (MVR) or MV repair at the time of cardiac surgery in the setting of isolated anterior mitral leaflet degenerative pathologic status in the US population is unknown. To investigate the prevalence of MVR and MV repair using the Society of Thoracic Surgeons' Adult Cardiac Surgery Database. In a cross-sectional study, all patients diagnosed with isolated anterior mitral leaflet degenerative regurgitation who underwent either surgical MVR or MV repair between July 1, 2011, and June 30, 2022, were identified. Linear regression analysis was used to assess trends over time. Assessment of the trends in MV repair and MVR over time. A total of 16 259 patients (9624 [59.2%] men) were identified, and the median age was 68 (IQR, 58-74) years. A total of 7214 patients (44.4%) had MVR, and 9045 (55.6%) had MV repair. There was a declining trend of MV repair from 58.0% in 2011 to 51.6% in 2022 (P = .05). The MVR group was older (median [IQR] age, 70 [62-77] vs 67 [58-74] years; P < .001) and had more comorbidities. A total of 85.1% of all patients underwent concomitant procedures. In 81.7% of MVR cases, no attempt at MV repair was made. The median (IQR) annual hospital volume was lower with MVR vs MV repair (2.50 [1.50-5.00] vs 4.00 [2.00-7.00]; P < .001). Conventional surgical approaches were most common (91.5%) but with a declining trend (P < .001). Minimally invasive approaches were used in 13.1% (robotic, 4.6%), and with an inclining trend from 5.0% in 2011 to 12.0% in 2022 (P < .001). Annuloplasty was performed in 88.8% of MV repair cases. Its use as a sole mean of MV repair decreased from 48.0% in 2011 to 13.9% in 2022 (P < .001). Repair maneuvers in addition to annuloplasty were neochordae (overall 40.1%, increasing from 22.5% in 2011 to 62.3% in 2022; P < .001), leaflet resection (overall 10.2%, decreasing from 13.1% in 2011 to 7.9% in 2022, P = .002), edge-to-edge MV repair (overall 5.3%, decreasing from 6.9% in 2011 to 4.5% in 2022; P = 0.04), and chordal transfer (overall 2.4%, decreasing from 2.7% in 2011 to 0.7% in 2022; P = .004). In this cross-sectional study, MV repair was the preferred option for degenerative mitral valve disease but was only slightly more commonly performed than MVR for isolated anterior leaflet pathologic status. A large proportion of MVR was performed without an MV repair attempt, suggesting reluctance to repair this pathologic condition.

Volumetric quantification identifies some left atrial dilations undetected by left atrium:aorta ratio measurements: A prospective echocardiographic study in 155 Cavalier King Charles Spaniels with and without degenerative mitral valve disease.

Degenerative mitral valve disease (DMVD) is the most common canine heart disease with a high predisposition in Cavalier King Charles Spaniels (CKCSs). Mitral regurgitation related to DMVD can lead to left atrial (LA) dilation, which is associated with survival time. Left-atrial-to-aortic (LA:Ao) ratio assessed by two-dimensional echocardiography is commonly used to evaluate LA size. The objectives of this prospective observational study were therefore 1) to compare different echocardiographic methods (i.e., monoplane and biplane Simpson's methods of discs (SMOD) and area-length methods (ALM)) in evaluating LA volume (LAvol) in CKCSs, 2) to assess LA volumes according to DMVD severity and, 3) compare the ability of LAvol and LA:Ao ratio to identify LA enlargement in CKCSs with subclinical DMVD (i.e., American College of Veterinary Internal Medicine (ACVIM) stage B). 155 CKCSs, either healthy or affected by DMVD, were recruited. Variability and concordance between volumetric methods were evaluated. Values were analyzed according to 2019 ACVIM stages. All Lin's concordance correlation coefficients regarding intra- and inter-observer variability were considered as very good to excellent. Monoplane methods and ALM produced higher values of LAvol than biplane methods and SMOD, respectively. The upper limit of normal end-systolic LAvol/body weight (LASvol/BW) was defined as 0.90 mL/kg. Left atrial volumes significantly increased with ACVIM stages. Additionally, 37% of stage B1 CKCSs demonstrated LA enlargement using LASvol/BW assessment, with significantly lower LASvol/BW values in dogs with regurgitation fraction ≤30% than in others (p<0.01). In CKCSs, LAvol methods are not interchangeable. In ACVIM stage B CKCSs, LAvol quantification is more effective to detect LA enlargement than LA linear measurements.

Pulmonary Hypertension Secondary to Myxomatous Mitral Valve Disease in Dogs: Current Insights into the Histological Manifestation and Its Determining Factors

Pulmonary venous hypertension (PVH) is caused by deteriorating left ventricular function. The most common cause of PVH in dogs is myxomatous mitral valve degeneration (MMVD). It causes left ventricular volume overload and an increase in left atrial and pulmonary venous pressure (PVH), which leads to pulmonary vascular wall remodeling and contributes to the perpetuation and worsening of PVH. Pulmonary vascular wall remodeling is also characteristic of pulmonary arterial hypertension (PAH). However, the changes in PVH arise secondary to heart failure and vascular remodeling progresses as the disease progresses. On the other hand, PAH is a primary disease that can be triggered, for example, by the use of certain drugs. Similar structural changes may suggest the influence of similar pathophysiological mechanisms or the intermediation of similar mediators. Therefore, this article discusses recent and hitherto uncommented findings elucidating the pathophysiology of the processes and influences on the pattern of histological changes observed in pulmonary hypertension secondary to degenerative mitral valve disease. In particular, we focus on the activity of factors such as endothelin, serotonin, and nitric oxide, which are involved in pulmonary vascular wall remodeling in both PVH and PAH.

Recognition and management of left atrial dissection during mitral repair

BackgroundLeft atrial dissection (LAtD) is a rare but potentially life-threatening complication of mitral valve surgery. Its management is not well stablished in the literature. However, early recognition through intraoperative TEE and attention to changes in the left atrial free wall during saline leak testing can lead to avoidance of severe complications.Case presentationWe report a case of LAtD detected by intraoperative transesophageal echocardiogram (TEE) following mitral valve repair for primary mitral valve regurgitation secondary to degenerative mitral valve disease with MAZE IV procedure for atrial fibrillation. LAtD was noted on TEE as an expanding double density along the wall of the left atrium with a jet originating at the posterior annulus flowing into the LAtD which was repaired. Separation from bypass following LAtD repair was complicated by severe biventricular dysfunction requiring significant inotropic support and placement of an intra-aortic balloon pump (IABP). Patient’s post-operative course was further complicated by right sided heart failure requiring placement of a right sided impella which was subsequently removed on POD 4. Patient was discharged home on POD 17. Transthoracic echo at 1 month, 3 months demonstrated resolution of the LAtD. A follow up echo at 4 years showed complete resolution of the LAtD with an intact mitral repair, trace mitral regurgitation, and a mean gradient across the repair of 3 mm Hg.ConclusionsLeft atrial dissection is a rare but serious complication of mitral valve surgery. We provide a review of the current literature regarding LAtD, emphasizing the need to consider this complication early during mitral surgery to allow for uncomplicated repair.

Transferring Surgical Expertise: Analyzing the Learning Curve of Robotic Cardiac Surgery Operative Time Reduction When Surgeon Moves from One Experienced Center to Another.

Robotically assisted cardiac surgery is performed in a team setting and is well known to be associated with learning curves. Surgeon and operative team learning curves are distinct entities, with total operative time representing the entire operative team (surgery, anesthesia, nursing, and perfusion) and cross-clamp time representing mainly the surgical team. Little is known about how a team learning curve evolves when an experienced surgeon transitions from one surgical center to another. This study investigates the dynamics of the team learning curve expressed as total operative time in the case of a surgeon with previous experience transitioning to a new team. A retrospective analysis was conducted on robotic cardiac surgeries performed by a surgeon who transitioned from one experienced surgical center to another. Operative time data were collected and categorized to assess the evolution of the learning curve. Statistical analysis, including learning curve modeling and linear regression analysis, was used to evaluate changes in total time in the operating room per case. 103 cases were included in Weill Cornell Medicine (2019-2023). The median patient age was 63 years, 68% were males, 90.3% of cases were repaired for degenerative mitral valve disease, and the median body mass index was 23.87. Operative time (ORT) decreased from a median of 5.00 h [95%CI: 4.76, 6.00] in the first 30 cases to 4.83 [95%CI: 4.10, 5.27] thereafter, with the apparent curve plateauing indicative of the adaptation period to the new surgical environment (p = 0.01). Subgroup analysis among mitral cases (n = 93) showed a decrease in ORT from 5.00 [95%CI: 4.71, 5.98] in the first 26 cases to 4.83 [95%CI: 4.14, 5.30] (p = 0.045). There was no difference between the initial 30 cases and subsequent cases regarding cardiopulmonary bypass time, myocardial ischemia time, reoperation for bleeding, prolonged ventilation, reintubation, renal failure, need for an intra-aortic balloon pump, readmission to the ICU, reoperation for valvular dysfunction within 30 days, pneumonia, and deep venous thrombosis. Multivariate significant predictors of longer operative time were the first 30 cases, resection-based repairs, and MAZE as a concomitant procedure. Total operative time can be expected to decrease after about 30 cases when an experienced robotic surgeon moves between centers. Complications and cross-clamp times are less susceptible to a learning curve phenomenon in such a circumstance, as these depend primarily on the operating surgeon's level of experience. Understanding these dynamics can inform the planning and management of surgical transitions, ensuring optimal patient care and continued improvement in surgical outcomes.

Navigating the challenges of minimally invasive mitral valve surgery: a risk analysis and learning curve evaluation

BackgroundThis study aimed to report the risk and learning curve analysis of a minimally invasive mitral valve surgery program performed through a right mini-thoracotomy at a single institution.MethodsFrom January 2013 through December 2019, 266 consecutive patients underwent minimally invasive mitral valve surgery in our department and were included in the current study. Multiple logistic regression analysis was used for the adverse event outcome. Distribution over time of perioperative complications, defined as clinical endpoints in the Valve Academic Research Consortium-2 (VARC-2) consensus document, as well as CUSUM charts for assessment of cardiopulmonary bypass and aortic cross-clamping duration over time, has been performed for learning curve assessment.ResultsOverall incidences of postoperative stroke (1.1%), myocardial infarction (1.1%), and thirty-day mortality (1.5%) were low. The mitral valve reconstruction rate in our series was 95%. Multivariable analysis revealed that concomitant tricuspid valve surgery (OR 4.44; 95%CI 1.61–11.80; p = 0.003) was significantly associated with adverse event outcomes. Despite a trend towards adverse event outcomes in patients with preexisting active mitral valve endocarditis (OR 2.69; 95%CI 0.81–7.87; p = 0.082), mitral valve pathology did not significantly impact postoperative morbidity and mortality. Distribution over time of perioperative complications, defined as clinical endpoints in the VARC-2 consensus document, showed a trend towards an improved complication rate after the initial 65–100 procedures.ConclusionsMitral valve surgery via right-sided mini-thoracotomy can be implemented safely with low perioperative morbidity and mortality rates. Careful patient selection regarding isolated mitral valve surgery in the presence of degenerative mitral valve disease may represent a significant safety issue during the learning curve.Trial Registration: The cantonal ethics commission of Zurich approved the study (registration ID 2020-00752, date of approval 24 April 2020).

Extended septal myectomy for obstructive hypertrophic cardiomyopathy and its impact on mitral valve function.

Septal myectomy is the treatment of choice for hypertrophic obstructive cardiomyopathy (HOCM). Around 30-60% of patients with HOCM have a secondary mitral valve regurgitation due to systolic anterior motion (SAM). We report our experience with extended septal myectomy and its impact on the incidence of concomitant mitral valve procedures. This is a retrospective study on 84 patients who underwent SM from January 2008 to February 2022. Surgical procedure was performed according to the concept of 'extended myectomy' described by Messmer in 1994. Follow-up outcomes in terms of survival, hospital admissions for heart failure or MV disease, cardiac reoperations, and pacemaker (PMK) implantation were recorded. Mean age was 61 ± 15 years. Mitral valve surgery was performed in seven cases (8%); particularly only one patient without degenerative mitral valve disease underwent mitral valve surgery, with a plicature of the posterior leaflet. In-hospital mortality was 5%. Mitral valve regurgitation greater than mild was present in four patients (5%) at discharge. Twelve-year survival was 78 ± 22%. Cumulative incidence of rehospitalization for heart failure and rehospitalization for mitral valve disease was 10 ± 4 and 2.5 ± 2.5%, respectively. PMK implantation was 5% at discharge, with a cumulative incidence of 15 ± 7%. Freedom from cardiac reoperations was 100%. Septal myectomy for HOCM is associated with good outcomes. Although concomitant surgery on the mitral valve to address SAM and associated regurgitation has been advocated, these procedures were needed in our practice only in patients with intrinsic mitral valve disease. Adequate myectomy addresses the underlying pathophysiology in most patients.

Proteomic analysis of pulmonary arteries and lung tissues from dogs affected with pulmonary hypertension secondary to degenerative mitral valve disease.

In dogs with degenerative mitral valve disease (DMVD), pulmonary hypertension (PH) is a common complication characterized by abnormally elevated pulmonary arterial pressure (PAP). Pulmonary arterial remodeling is the histopathological changes of pulmonary artery that has been recognized in PH. The underlying mechanisms that cause this arterial remodeling are poorly understood. This study aimed to perform shotgun proteomics to investigate changes in protein expression in pulmonary arteries and lung tissues of DMVD dogs with PH compared to normal control dogs and DMVD dogs without PH. Tissue samples were collected from the carcasses of 22 small-sized breed dogs and divided into three groups: control (n = 7), DMVD (n = 7) and DMVD+PH groups (n = 8). Differentially expressed proteins were identified, and top three upregulated and downregulated proteins in the pulmonary arteries of DMVD dogs with PH including SIK family kinase 3 (SIK3), Collagen type I alpha 1 chain (COL1A1), Transforming growth factor alpha (TGF-α), Apoptosis associated tyrosine kinase (AATYK), Hepatocyte growth factor activator (HGFA) and Tyrosine-protein phosphatase non-receptor type 13 (PTPN13) were chosen. Results showed that some of the identified proteins may play a role in the pathogenesis of pulmonary arterial remodeling. This study concluded shotgun proteomics has potential as a tool for exploring candidate proteins associated with the pathogenesis of PH secondary to DMVD in dogs.

Outcomes of Mitral Valve Repair for Degenerative Mitral Disease: A Single-Centre 10-Year Experience

To evaluate the long-term outcomes of degenerative mitral valve (MV) repair. This study analysed 1,069 patients who underwent MV repair due to degenerative MV disease at Beijing Anzhen Hospital from January 2010 to December 2019. All patients were clinically followed until December 2019, with an average follow-up period of 4.7 years. Perioperative complications, 30-day mortality, long-term outcomes, and risk factors of all-cause death and recurrent mitral regurgitation (MR) were summarised. Ten patients died in the hospital and 33 died during the follow-up period. Recurrent MR occurred in 113 patients. Fourteen patients underwent re-operation. Rates of long-term survival, absence of recurrent MR, and no re-operation were 94.0% (91.6%-96.6%), 81.2% (77.3%-85.3%), and 98.2% (97.2%-99.3%), respectively. The risk factors for long-term all-cause death included age and an ejection fraction (EF) <60%. The risk factors for recurrent MR included age, female sex, E-wave velocity, anterior prolapse, residual 1+MR postoperatively, and lower body mass index. Mitral valve repair is an effective treatment for degenerative MV disease that, in an experienced heart centre, can be performed with low mortality, recurrence, and re-operation rates. Advanced age and an EF <60% were risk factors for long-term all-cause death. Age, female sex, residual 1+MR postoperatively, lower body mass index, higher peak E-wave velocity, and anterior prolapse were risk factors for recurrent MR.

Indicators for pulmonary hypertension in dogs with degenerative mitral valve disease.

Pulmonary hypertension (PH) is a common complication of degenerative mitral valve disease (DMVD) in dogs. This study aimed to determine PH indicators in dogs with stage C DMVD through thoracic radiography and M-mode and 2-dimensional echocardiography. A retrospective study of 133 dogs with DMVD stage C was conducted. The patients were divided into two groups: DMVD and DMVD with PH. Characteristics, thoracic radiographic findings, and echocardiographic variables were recorded for analysis. Pulmonary hypertension was diagnosed in 56 dogs, with a prevalence of 42.1%. Univariable logistic regression analysis revealed associations among PH and right-sided heart enlargement, pulmonary artery enlargement, left ventricular size, and percent fractional shortening. Multivariable logistic regression analysis demonstrated that pulmonary artery enlargement (odds ratio [OR]: 5.96; 95% confidence interval [CI]: 1.45-24.54; p = 0.014) and decreased left ventricular size (OR: 0.02; 95%CI: 0.003-0.13; p = 0.001) were significantly associated with PH. The accuracy of predicting PH in dogs at DMVD stage C using pulmonary artery enlargement combined with decreased left ventricular size was moderate (area under the curve [AUC] 0.77; 95%CI: 0.68-0.86). Pulmonary hypertension is common in dogs with DMVD stage C. The presence of pulmonary artery enlargement assessed by radiography and decreased left ventricular size assessed by echocardiography, were associated with PH and may serve as predictors of PH in DMVD stage C.

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.

Alerting trends in epidemiology for non-rheumatic degenerative mitral valve disease, 1990–2019: An age-period-cohort analysis for the Global Burden of Disease Study 2019

BackgroundThe global and national burden of rheumatic mitral valve disease (MVD) has been well studied and estimated before. However, little is known about non-rheumatic degenerative MVD. Therefore, this study aimed to assess the trends in non-rheumatic degenerative MVD (NRDMVD) epidemiology, with an emphasis on NRDMVD mortality, leading risk factors, and their associations with age, period, and birth cohort. MethodsUsing the data derived from the Global Burden of Disease Study 2019, including prevalence, mortality, and disability-adjusted life years, we analyzed the burden of NRDMVD and the detailed trends of NRDMVD mortality over the past 30 years in 204 countries and territories by implementing the age-period-cohort framework. ResultsGlobally, the number of deaths due to NRDMVD increased from 5695.89 (95% uncertainty interval [UI]: 5405.19 to 5895.4) × 1000 in 1990 to 9137.79 (95% UI: 8395.68 to 9743.55) × 1000 in 2019. The all-age mortality rate increased from 106.47 (95% UI: 101.03 to 110.2) per 100,000 to 118.1 (95% UI: 108.51 to 125.93) per 100,000, whereas the age-standardized mortality rate decreased from 170.45 (95% UI: 159.61 to 176.94) per 100,000 to 117.95 (95% UI: 107.83 to 125.92) per 100,000. The estimated net drift of mortality per year was −1.1% (95% confidence interval: −1.17 to −1.04). The risk of death due to NRDMVD increased with age, reaching its peak after 85 years old globally. Despite female patients being associated with lower local drift than male patients, no significant gender differences were observed in the age effect across countries and regions for all sociodemographic index (SDI) levels, except low-SDI regions. ConclusionsWe estimated the global disease prevalence of and mortality due to NRDMVD over approximately a 30-year period. The health-related burden of NRDMVD has declined worldwide; however, the condition persisted in low-SDI regions. Moreover, higher attention should be paid to female patients.

Sex-Based Differences in Early Outcomes Following Mitral Valve Surgery for Degenerative Disease

Objectives: To determine whether sex-based differences exist following surgery for degenerative mitral valve disease. Methods: Using a national database, we analysed data on mitral valve surgery for degenerative disease (n = 22,658) between January 2000 and March 2019 in the UK. We split the cohort into men (n = 14,681) and women (n = 7977) and compared background characteristics, intraoperative variables and early postoperative outcomes. Our primary outcome was hospital mortality; secondary outcomes included re-exploration for bleeding, prolonged admission (&gt;10 days) and mitral replacement. We used binary logistic regression models for all outcomes, with multiplicative interaction terms to determine the nature of any differences. Results: Women presented older (70 ± 11 years vs. 67 ± 11 years, p &lt; 0.001) with worse symptom profiles (New York Heart Association Class III–IV 57% vs. 44%, p &lt; 0.001). They had higher rates of preoperative atrial fibrillation (39% vs. 35%, p &lt; 0.001) and tricuspid disease requiring surgery (21% vs. 15%, p &lt; 0.001). They had lower repair rates (66% vs. 76%, p &lt; 0.001), higher mortality (3% vs. 2%, p &lt; 0.001) and were more likely to have a prolonged admission (48% vs. 40%, p &lt; 0.001). Female sex was an independent predictor of mortality (odds ratio (OR): 1.52, 95% CI: 1.21–1.90, p &lt; 0.001). Age and Canadian Cardiovascular Society (CCS) score showed significant interactions with sex. The relationship between advancing age and mortality was found to be more pronounced in women. Conclusions: (1) Female sex is an independent predictor of hospital mortality, prolonged hospital admission and mitral valve replacement. (2) The relationship between female sex and mortality is exacerbated by worsening CCS score and advancing age. (3) Women have significantly lower repair rates.

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.

Repeat crossclamp after failed initial degenerative mitral valve repair is safe and successful

ObjectiveSurgical risk and long-term outcomes when re-crossclamp is required during degenerative mitral valve repair are unknown. We examined the outcomes of patients who required re-crossclamp for mitral valve reintervention. MethodsAdults undergoing mitral valve repair for degenerative mitral valve disease at a single center from 2007 to 2021 who required more than 1 crossclamp for mitral valve reintervention were included. Outcomes including major morbidity and 30-day mortality were collected. Kaplan–Meier analysis characterized survival and freedom from recurrent mitral regurgitation. ResultsA total of 69 patients required re-crossclamp for mitral valve reintervention. Of those, 72% (n = 50) underwent successful re-repair and the remaining underwent mitral valve replacement (28%, n = 19). Major morbidity occurred in 23% (n = 16). There was no 30-day mortality, and median long-term survival was 10.9 years for those undergoing re-repair and 7.2 years for those undergoing replacement (P = .79). Midterm echocardiography follow-up was available for 67% (33/50) of patients who were successfully re-repaired with a median follow-up of 20 (interquartile range, 7-37) months. At late follow-up, 90% of patients had mild or less mitral regurgitation. Of those re-repaired, 2 patients later required mitral valve reintervention. ConclusionsPatients requiring re-crossclamp for residual mitral regurgitation had low perioperative morbidity and no mortality. Most patients underwent successful re-repair (vs mitral valve replacement) with excellent valve function and long-term survival. In the event of unsatisfactory repair at the time of mitral valve repair, attempt at re-repair is safe and successful with the appropriate valvar anatomy.

Global, regional, and national incidence, mortality, and disability-adjusted life years of non-rheumatic valvular heart disease and trend analysis from 1990 to 2019: Results from the Global Burden of Disease study 2019.

In the context of the population growing and aging worldwide, the incidence of non-rheumatic valvular heart disease increased rapidly. This study aimed to describe the burden of non-rheumatic valvular heart disease, providing an up-to-date and comprehensive analysis on the global and regional levels and time trends from 1900 to 2019. The Global Burden of Disease 2019 was used to obtain data for this analysis. Non-rheumatic valvular heart disease in the Global Burden of Disease study includes both non-rheumatic calcific aortic valve disease and non-rheumatic degenerative mitral valve disease. The incidence, mortality, and disability-adjusted life year in 204 countries from 1990 to 2019 were analyzed by location, year, sex, age, and socio-demographic index. Estimated annual percentage change was calculated to represent the temporal trends from 1990 to 2019. Spearman's rank order correlation was used to determine the correlation between socio-demographic index and the incidence and burden of non-rheumatic valvular heart disease. Globally, there were 1.65 million (95% uncertainty interval, 1.56-1.76 million) incident cases, 0.16 million (95% uncertainty interval, 0.14-0.18 million) death cases, and 2.79 million (95% uncertainty interval, 2.52-3.31 million) disability-adjusted life years of non-rheumatic valvular heart disease. Compared with 1990, the number of incident cases, death cases, and disability-adjusted life years in 2019 increased by 104.58%, 210.60%, and 167.62%, respectively, the age-standardized incidence rate (estimated annual percentage change, 0.39; 95% confidence interval, 0.29 to 0.49) increased due to population growth, and the age-standardized death rates (estimated annual percentage change, -0.32; 95% confidence interval, -0.39 to -0.25) and age-standardized disability-adjusted life year rate (estimated annual percentage change, -0.81; 95% confidence interval, -0.87 to -0.74) decreased during this period. Regarding the socio-demographic index, the highest age-standardized incidence, death, and disability-adjusted life year rates of non-rheumatic valvular heart disease were found in high-socio-demographic index countries in 2019. Meantime, the age-standardized incidence rate remained increased from 1990 to 2019, while significant decreases were found in the age-standardized death rate and age-standardized disability-adjusted life year rate. Females have higher age-standardized incidence rate, while higher age-standardized death rate and age-standardized disability-adjusted life year rate belong to males globally during the period of 1990-2019. Increasing trends were observed for both incidence, death, and disability-adjusted life year rates with age. High systolic blood pressure was the leading cause for non-rheumatic valvular heart disease across all ages. From 1990 to 2019, the age-standardized incidence rate of non-rheumatic valvular heart disease remained increased, while age-standardized death rate and age-standardized disability-adjusted life year rate decreased, resulting from the growing population worldwide and improving medical resources. The aged, who has high systolic blood pressure and diet high in sodium, should pay more attention to, especially in high-socio-demographic index regions. With the population aging, the number of patients who require heart valve replacement is estimated to increase significantly in the future. Effective measures are warranted to control and treat the incidence and burden of non-rheumatic valvular heart disease.

Mitral Annular Disjunction: A Scoping Review.

Mitral annular disjunction (MAD) is the atrial displacement of the mitral valve (MV) hinge point, especially along the posterior mitral leaflet, which leads to inhomogeneous blood flow into the left ventricle, causing chronic fibrotic changes, malignant arrhythmias, and even sudden cardiac arrest. Some studies suggest that MAD is a part of normal heart morphology; however, the origin is still controversial. MAD commonly occurs with MV prolapse and myxomatous degenerative MV disease. In almost 20% of cases, MAD can occur independently as well. The prevalence of MAD in normal hearts varies from 8.6% to 96%, depending on the imaging modality and the cutoff used to define MAD. Transthoracic echocardiography is often the initial screening test, but the low sensitivity of transthoracic echocardiography to identify MAD makes it easy to miss the diagnosis altogether. More advanced imaging, especially cardiac MRI, is the gold standard for diagnosing MAD and risk stratification. MAD is an independent predictor of malignant arrhythmia. Among patients with MAD, risk stratification is based on the age at diagnosis, previous syncopal attacks, premature ventricular contractions, papillary muscle fibrosis, and longitudinal disjunction distance. Most asymptomatic patients are managed conservatively; however, radiofrequency ablation should be considered in patients with high-risk or symptomatic MAD due to the risk of ventricular arrhythmias and sudden cardiac death.

Effect of a specially formulated diet on progression of heart enlargement in dogs with subclinical degenerative mitral valve disease.

Previous studies in dogs with degenerative mitral valve disease (DMVD) have identified altered myocardial energy metabolism and oxidation, which might contribute to cardiac hypertrophy. Diets rich in medium chain fatty acids and antioxidants are a potential means of treatment. A previous clinical study found significantly smaller left atrial diameter (LAD) and left atrium-to-aorta diameter ratio (LA : Ao) in dogs with subclinical DMVD fed a specially formulated diet vs control diet for 6 months. A specially formulated diet will slow or arrest left heart enlargement in dogs with subclinical DMVD over 365 days. One hundred twenty-seven dogs with unmedicated subclinical DMVD; 101 dogs in the per protocol cohort. Randomized double-blinded controlled multicenter clinical trial. The study's primary composite outcome measure was the sum of percentage change in LAD and left ventricular internal dimension at end-diastole (LVIDd) at day 365. In the per protocol cohort, the outcome measure increased by 8.0% (95% confidence interval [CI], 2.9%-13.1%) in dogs receiving the test diet vs 8.8% (95% CI, 5.1%-12.5%) in dogs receiving control diet (P = .79). Neither component of the primary outcome measure was significantly different between groups (LAD, P = .65; LVIDd, P = .92). No difference was found in mitral valve E wave velocity (P = .36) or the proportion of dogs withdrawn from the study because of worsening DMVD and heart enlargement (P = .41). Feeding a specially formulated diet for 365 days was not associated with a significantly different rate of change of left heart size in dogs with subclinical DMVD as compared to control.

Mechanical behavior and collagen structure of degenerative mitral valve leaflets and a finite element model of primary mitral regurgitation.

Degenerative mitral valve disease is the main cause of primary mitral regurgitation with two phenotypes: fibroelastic deficiency (FED) often with localized myxomatous degeneration and diffuse myxomatous degeneration or Barlow's disease. Myxomatous degeneration disrupts the microstructure of the mitral valve leaflets, particularly the collagen fibers, which affects the mechanical behavior of the leaflets. The present study uses biaxial mechanical tests and second harmonic generation microscopy to examine the mechanical behavior of Barlow and FED tissue. Three tissue samples were harvested from a FED patient and one sample is from a Barlow patient. Then we use an appropriate constitutive model by excluding the collagen fibers under compression. Finally, we built an FE model based on the echocardiography of patients diagnosed with FED and Barlow and the characterized material model and collagen fiber orientation. The Barlow sample and the FED sample from the most affected segment showed different mechanical behavior and collagen structure compared to the other two FED samples. The FE model showed very good agreement with echocardiography with 2.02±1.8mm and 1.05±0.79mm point-to-mesh distance errors for Barlow and FED patients, respectively. It has also been shown that the exclusion of collagen fibers under compression provides versatility for the material model; it behaves stiff in the belly region, preventing excessive bulging, while it behaves very softly in the commissures to facilitate folding. STATEMENT OF SIGNIFICANCE: This study quantifies for the first time the collagen microstructure and mechanical behavior of degenerative mitral valve (DMV) leaflets. These data will then be used for the first disease-specific finite element (FE) model of DMV. While current surgical repair of DMV is based on surgical experience, FE modeling has the potential to support decision-making and make outcomes predictable. We adopt a constitutive model to exclude collagen fiber under compressions, an important consideration when modeling the mitral valve, where the leaflets are folded to ensure complete closure. The results of this study provide essential data for understanding the relationship between collagen microstructure and degenerative mitral valve mechanics.