Degenerative Mitral Valve Disease Research Articles

Heart Rate and Rhythm Changes in Dogs Treated in a Hyperbaric Oxygen Chamber

In veterinary medicine, hyperbaric oxygen chamber treatment (HBOT) is gaining popularity. Therefore, an increasing number of patients referred for this therapy are being recorded, mainly due to ischemic events, wound healing support, and a high risk of reperfusion damage. During the HBOT procedure, several changes occur in the body’s micro- and macroenvironments. This study involved 34 dogs of various ages and health statuses. The atmospheric conditions in the test hyperbaric chamber included a pressure of 1.5 atmosphere absolute (ATA) at 100% oxygenation. The individuals were divided into three groups: (1) individuals with degenerative mitral valve disease (DMVD), (2) individuals with diseases other than cardiac issues, and (3) healthy individuals who qualified for the HBOT procedure. The period of measurement using the Holter apparatus was divided into four stages: 30 min before the subject’s placement in the hyperbaric chamber; a 4-min compression period (setting chamber conditions); a 90 min HBOT period; and a 1 min decompression period of the hyperbaric chamber. During the HBOT, there was a statistically significant decrease in heart rate in groups 2 and 3 compared to group 1. The heart rate in group 1 remained unchanged through every period of the study. In addition, some of the dogs developed respiratory arrhythmia; in two dogs, premature ventricle beats occurred. The changes observed during the ventricular period indicate that the HBOT procedure causes a significant change in heart rate in dogs without cardiac diseases.

Cost-effectiveness analysis of valvular surgery in high- and low- to middle-income countries: A scoping review.

Global disparities in valvular surgery services exist. Cost-effectiveness analysis (CEA) and cost-utility analysis can be used to guide national investment decisions. This scoping review aims to synthesize economic evaluations for valvular surgery by income settings and provide recommendations. A systematic literature review identified primary CEAs or CUAs in English comparing surgical management strategies for valvular heart disease. MEDLINE, Embase, CINAHL, Web of Science, and Business Source Complete were searched using keywords "valvular surgery," "valve disease," "cost-effectiveness," and "cost-benefit analysis". Articles comparing outcomes or costs only were excluded. Search results were uploaded and screened on COVIDENCE. Variables from eligible articles were charted in a spreadsheet. Twenty articles were eligible, six from low- and middle-income countries (LMICs) and 14 from high-income countries (HICs). In HICs, the top conditions were degenerative aortic valve disease (7/14) and mitral valve disease (4/14) compared to congenital (2/6) and rheumatic heart diseases (2/6) in LMICs. HICs evaluated new technologies and techniques, whereas LMICs compared different valve types or surgery versus no intervention. Most articles used published studies (12/20) or databases (7/20) to conduct their CEA and quality-adjusted life years was the most common effectiveness measure (12/20). Comparator interventions were cost-effective in all LMIC articles and in 8/14 for HICs. Economic evaluations are mostly conducted in HICs and for adult conditions. More analyses in LMICs are needed. This can be facilitated by maintaining databases, documenting costs, and implementing quality of life assessments.

TCT-644 Burden of Non-Rheumatic Calcific Aortic Valve Disease and Non-Rheumatic Degenerative Mitral Valve Disease in High-Income North America and West Europe From 1990 to 2021

TCT-644 Burden of Non-Rheumatic Calcific Aortic Valve Disease and Non-Rheumatic Degenerative Mitral Valve Disease in High-Income North America and West Europe From 1990 to 2021

Is concomitant tricuspid valve repair in patients undergoing robotic mitral valve repair safe and effective?

ObjectivesRobotic-assisted mitral valve repair (MVr) is a well-established procedure for management of degenerative mitral valve disease. Limited data regarding concomitant robotic-assisted tricuspid valve repair (TVr) is available. This review investigates prevalence and outcomes of concomitant robotic-assisted mitral and tricuspid valve repair. MethodsFrom 2014 to 2022, 839 patients underwent robotic-assisted MVr, including 76 patients with moderate or greater tricuspid regurgitation and/or tricuspid annular dilatation ≥40 mm. Among the 76 patients, 19 (25%) underwent isolated MVr and 57 (75%) had concomitant mitral and tricuspid valve repair. Outcome data between the 2 groups were analyzed. ResultsIn the MVr/TVr group, tricuspid regurgitation grades were mild in 4 (7%) patients, moderate in 44 (77%) and severe in 9 (15.7%). Significant tricuspid annular dilatation ≥40 mm was present in all patients. In the isolated MVr group, 3 (15.7%) patients had mild tricuspid regurgitation and 16 (84.2%) had moderate tricuspid regurgitation with significant tricuspid annular dilatation present in only 6 patients. Cardiopulmonary bypass and crossclamp time were 130.6 and 91 minutes versus 85 and 55.4 minutes for robotic MVr/TVr group versus MVr group, respectively (P < .05). The intensive care unit and hospital length of stay were similar: 27.7 versus 27.7 hours and 4.4 versus 4.2 days for MVr/TVr versus MVr (P = .24), respectively. There were no perioperative deaths or heart block in either group. Survival and freedom from reoperation with median follow-up of 16 and 46 months for MVr/TVr and MVr groups, respectively were 100%. ConclusionsConcomitant robotic-assisted tricuspid valve repair for functional regurgitation can be safely and effectively performed at the time of mitral valve repair with excellent short-term morbidity and mortality results.

Left atrial volume and function in Cavalier King Charles spaniels at different ACVIM stages

BackgroundThe correct assessment of left atrial size and function is essential to evaluate the severity of degenerative mitral valve disease in dogs. Hypothesis/objectivesEvaluate left atrial (LA) dimension and function in Cavalier King Charles Spaniel (CKCS) at different ACVIM stages and the accuracy of linear and volumetric indexes to assess LA enlargement. AnimalsOne hundred and ninety-eight privately owned CKCS. MethodsMulticentric prospective observational cross-sectional study. Dogs underwent an echocardiographic exam for breed screening or cardiac examination. Linear and volumetric echocardiographic LA size and function indexes were compared between classes. ResultsDogs were allocated as follows: 43 in class ACVIM A, 58 ACVIM B1, 55 ACVIM B2, and 42 ACVIM C/D. Only LA anteroposterior diameter normalized on body weight (LADn) and LA maximal, minimal and P volumes (LAVmax, LAVmin, LAVP) differed across all pairwise comparisons. Active LA emptying fraction (aLAEF) was higher in class B1 compared to class A (P < .001), and then decreased in class C/D compared to class B2 (P < .001). This suggests an increase in the left atrial active component due to the Frank-Starling mechanism in ACVIM B1 dogs, and the presence of atrial dysfunction in symptomatic dogs. Conclusions and clinical importanceThe LADn and LAV are higher in CKCS in class ACVIM B1 compared to class ACVIM A, suggesting the presence of LA remodelling at the early stages of the disease. Atrial dysfunction is evident in symptomatic dogs.

Metabolic gene therapy in a canine with pulmonary hypertension secondary to degenerative mitral valve disease.

Myxomatous mitral valve disease (MMVD) stands out as the most prevalent acquired canine heart disease. Its occurrence can reach up to 40% in small breed dogs and escalates in geriatric canine populations. MMVD leads to thickening and incomplete coaptation of valve leaflets during systole, resulting in secondary mitral valve regurgitation. Serious complications may arise concurrently with the worsening of mitral valve regurgitation, including left-and right-sided congestive heart failure, and pulmonary hypertension (PH). Ultimately, the PH progression might contribute to the patient's demise or to the owner's decision of euthanasia. Most currently available FDA-approved therapies for PH are costly and aim to address the imbalance between vasoconstriction and vasodilation to restore endothelial cell function. However, none of these medications impact the molecular dysfunction of cells or impede the advancement of pulmonary vascular and right ventricular remodeling. Recent evidence has showcased successful gene therapy approaches in laboratory animal models of PH. In this manuscript, we summarize the latest advancements in gene therapy for the treatment of PH in animals. The manuscript incorporates original data showcasing sample presentations, along with non-invasive hemodynamic assessments. Our findings demonstrate that the use of metabolic gene therapy, combining synthetic adeno-associated virus with acid ceramidase, has the potential to significantly reduce the need for drug treatment and improve spontaneously occurring PH in dogs.

The prevalence, etiologies and clinical consequences of tricuspid regurgitation associated with severe degenerative mitral regurgitation.

The prevalence, the etiologies and the clinical features of tricuspid regurgitation (TR) in the context of concomitant degenerative mitral valve (MV) disease are poorly defined. This paper aims to assess the prevalence, determinants and clinical consequences of TR in severe degenerative mitral regurgitation (DMR). Clinical and echocardiographic characteristics were collected among patients with severe DMR. 884 patients were included in our study, 31% with > moderate TR. Tricuspid valve prolapse (TVP) was the most common etiology (487 patients, 55%), followed by atrial functional TR (AFTR, 172 patients, 19%) and ventricular functional TR (VFTR, 42 patients, 5%), while TR etiology was mixed in 183 (21%) patients. Patients with TVP were younger, had better clinical presentation, had few comorbidities, and had less hemodynamically relevant TR. VFTR patients were characterized by older age, worst clinical presentation and both highest comorbidity rate and prevalence of >mild TR. AFTR group showed an intermediate profile of clinical presentation and comorbidities and the largest tricuspid annulus (TA) diameter.MV surgery was performed in 785 (88%) patients; 132 (15%) underwent simultaneous TV intervention, more often AFTR patients (32%). TA dilatation (OR 3.68, CI 2.05-6.62, p <0.001) and >mild TR (OR 9.30, CI 5.10-16.95, p<0.001) were independently associated with TV intervention. In patients with severe DMR, TR presents with different etiologies, clinical features and echocardiographic phenotypes that require a comprehensive assessment at the time of DMR surgery to ensure the best management for these patients.

Recurrent mitral regurgitation after repair of Barlow's disease in a single-center retrospective cohort study.

Barlow's disease (BD) is a common etiology of degenerative mitral valve (MV) disease, often causing significant mitral regurgitation (MR). The pathology of BD is challenging for surgeons performing MV repair (MVR). However, most MVR effectiveness studies have been based on survival and risk of reoperation. The aim of this study was to analyze the safety, efficacy, and durability of MVR in patients with BD and to identify factors that influence recurrent MR. We retrospectively analyzed the clinical outcomes of 274 patients undergoing MVR for BD at a tertiary hospital (Guangdong People's Hospital, Guangzhou, China) between January 2010 and June 2022. To analyze the results of MVR and identify the risk factors for MR recurrence, we defined two groups: a total of 240 patients with MR grade <2+ (group A) and a total of 34 patients who had recurrent MR after MVR (group B; the patients with MR ≥2+). All patients were operated on using standard repair techniques. Recurrent MR was the primary outcome. Secondary outcomes were death and reoperation after MVR. Patients were followed up until March 2023. Patients were followed up by clinic visits, telephone calls, and postal or electronic questionnaires. The median [range] patient age was 46.00 [16-75] years and 186 (67.9%) patients were male. Concomitant procedures were performed in 123 patients: tricuspid valve repair 71 (25.9%), maze or pulmonary vein isolation (PVI) 12 (4.4%), atrial septal defect (ASD) repair 3 (1.1%), and left atrial appendage (LAA) closure 28 (10.2%). Hospital mortality was 0.4%. Long-term complications included radiofrequency ablation in 7 patients (2.6%), pacemaker implantation in 1 patient (0.4%), and stroke in 3 patients (1.1%). The median follow-up was 3.28 (range, 0-12.39) years. Considering the competing risk of mortality, the cumulative incidence of MR progression 2+ or more grades was 2.6%, 5.9%, 14.5%, and 27.7% at 1 month, 1, 5, and 10 years, respectively. Overall survival at 1, 5, and 10 years was 99.3%, 98.6%, and 98.6%, respectively. The immediate postoperative MR area [hazard ratio (HR) =1.723; 95% confidence interval (CI): 1.051-2.824; P=0.031], postoperative left ventricular end-diastolic dimension (LVEDD) (HR =1.149; 95% CI: 1.016-1.300; P=0.027), and postoperative MR grade {HR = Exp[4.500 - 0.544 × ln(t + 20)]; P=0.008} were associated with an increased risk of MR recurrence, whereas a higher left ventricular ejection fraction (LVEF) (HR =0.931; 95% CI: 0.868-0.999; P=0.049) was associated with a decreased risk. MVR in patients with BD can be performed with low mortality and complications and is associated with superior long-term outcomes. However, MVR was associated with a certain risk of MR recurrence, especially in those with high postoperative LVEDD, residual MR >1+, and decreased postoperative LVEF. We recommend MVR for patients with BD, especially for those with early-stage disease. However, future randomized controlled trials are needed to confirm this.

Quantified planar collagen distribution in healthy and degenerative mitral valve: biomechanical and clinical implications

Degenerative mitral valve disease is a common valvular disease with two arguably distinct phenotypes: fibroelastic deficiency and Barlow’s disease. These phenotypes significantly alter the microstructures of the leaflets, particularly the collagen fibers, which are the main mechanical load carriers. The predominant method of investigation is histological sections. However, the sections are cut transmurally and provide a lateral view of the microstructure of the leaflet, while the mechanics and function are determined by the planar arrangement of the collagen fibers. This study, for the first time, quantitatively examined planar collagen distribution quantitatively in health and disease using second harmonic generation microscopy throughout the thickness of the mitral valve leaflets. Twenty diseased samples from eighteen patients and six control samples were included in this study. Healthy tissue had highly aligned collagen fibers. In fibroelastic deficiency they are less aligned and in Barlow’s disease they are completely dispersed. In both diseases, collagen fibers have two preferred orientations, which, in contrast to the almost constant one orientation in healthy tissues, also vary across the thickness. The results indicate altered in vivo mechanical stresses and strains on the mitral valve leaflets as a result of disease-related collagen remodeling, which in turn triggers further remodeling.

Global Epidemiologic Trends and Projections to 2030 in Non-Rheumatic Degenerative Mitral Valve Disease from 1990 to 2019: An Analysis of the Global Burden of Disease Study 2019.

No studies have updated the epidemiologic changes in non-rheumatic degenerative mitral valve disease (DMVD) since 2019, thus this study utilized data from the Global Study of Diseases, Injuries, and Risk Factors 2019 (GBD2019) to assess the burden of DMVD in 204 countries and territories over the period 1990-2019, as well as changes in the prevalence, incidence, deaths and changes in disability-adjusted life years (DALYs). Using the results from the GBD2019, analyzing the incidence, prevalence, deaths, and DALYs rates, as well as their age-standardized rates (ASR). Based on the human development index (HDI), the socio-demographic index (SDI), age, and sex. In 2019, there were 24.229 million (95% uncertainty interval (UI) 23.081-25.419 million) existing cases of DMVD worldwide, with 1.064 million (95% UI 1.010-1.122 million) new cases and 0.034 million (95% UI 0.028-0.043 million) deaths, and 0.883 million (95% UI 0.754-1.092 million) disability-adjusted life years. The incidence, prevalence, deaths, and DALYs of DMVD and their ASR showed significant differences across sex, age groups, regions, and countries from 1990 to 2019. It is projected that by 2030, the incidence of DMVD in females will be 0.72 million with an ASR of 15.59 per 100,000 population, 0.51 million in males with an ASR of 11.75 per 100,000 population, and a total incidence of 1.23 million with an ASR of 14.03 per 100,000 population. DMVD remains a significant public health problem that cannot be ignored, despite a decreasing trend in the ASR of global incidence, prevalence, deaths and DALYs from 1990 to 2019. However, we note an adverse development trend in countries with low socio-demographic indexes and seriously aging societies, and sex inequality is particularly prominent. This indicates the need to reposition current prevention and treatment strategies, with some national health administrations developing corresponding strategies for preventing an increase in DMVD based on local health, education, economic conditions, sex differences, and age differences.

Two-dimensional transthoracic measure of mitral annulus in mitral valve prolapse and moderate to severe regurgitation: a method comparison analysis with three-dimensional transesophageal echocardiography

BackgroundMitral annulus (MA) area is derived during transthoracic echocardiography (TTE) assuming of a circular shape using the MA diameter from the apical 4 chamber (A4c) view. Since the MA is not a circular structure, we hypothesized that an elliptical model using parasternal long-axis (PLAX) and apical 2 chamber (A2c) view measured MA diameters would have better agreement with 3-dimensional transesophageal echocardiography (3D TEE) measured MA in degenerative mitral valve disease (DMVD).MethodsSeventy-six patients with moderate-to-severe DMVD had 2D TTE and 3D TEE performed. MA area was measured retrospectively using semi-automatic modeling of 3D data (3D TEEsa) and considered as the reference method. MA diameters were measured using different 2D TTE views. MA area was calculated using assumptions of a circular or an elliptical shape. 2D TTE derived and 3D TEEsa. MA areas were compared using linear regression and Bland-Altman analysis.ResultsThe median MA area measured at 3D TEEsa was 1,386 (1,293–1,673) mm2. With 2D TTE, the circular model using A4c view diameter resulted in a small systematic underestimation of MA area (6%), while the elliptical model using PLAX and A2c diameters resulted in 25% systematic underestimation. The standard deviations of the distributions of inter-method differences were wide for all 2D TTE methods (265–289 mm2) when compared to 3D TEEsa, indicating imprecision.ConclusionsWhen compared with 3D TEEsa modeling of the MA as the reference, the assumption of a circular shape using A4c TTE view diameter was the method with the least systematic error to assess MA area in DMVD and moderate to severe regurgitation.

Simultaneous Tricuspid Valve Repair at the Time of Mitral Valve Surgery: Determinants of Postoperative Pacemaker Implantation

Guidelines recommend tricuspid valve (TV) repair for patients with severe tricuspid valve regurgitation (TR) undergoing surgery for degenerative mitral valve (MV) disease, but management of ≤ moderate TR is controversial. This study examines the incidence and causes of bradyarrhythmias leading to PPM implantation. Review of patients undergoing simultaneous TV repair and MV surgery for degenerative MV disease from 2001 to 2022 (N=404). Primary endpoint was the incidence of postoperative PPM implantation. Secondary endpoints included the incidence of high-degree AV block and overall survival. All patients underwent TV repair at the time of MV surgery; 332 (82%) underwent MV repair and 72 (18%) MV replacement. Tricuspid valve repair techniques included flexible band (n=258, 63.8%), DeVega annuloplasty (n=78, 19.3%), complete flexible ring (n=49, 12.1%), and incomplete rigid ring (n=19, 4.7%). The 30-day mortality was 0.5% (n=2). A total of 35 (8.7%) patients had a PPM implanted postoperatively, 26 (6.4%) for high-degree AV block. On multivariable analysis, only older age was associated with PPM implantation. Patients who received a PPM due to high-degree AV block had reduced overall survival (Figure, p=0.01). Need for permanent pacing following TV repair at the time of MV surgery is not uncommon, but there are few modifiable factors that might reduce this risk. Careful selection of patients with less-than-severe TR and surgical techniques may reduce PPM-related risks and complications.

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.

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.