Mitral Valve Pathology Research Articles

New Insights on the Formation of the Mitral Valve Chordae Tendineae in Fetal Life.

There is an increasing understanding that some mitral valve pathologies have developmental origins. The time course of valvulogenesis varies by animal model; in cattle, the branched chordae tendineae architecture becomes fully developed at full term. The mechanism by which chordae tendineae bifurcate during fetal development remains unknown. The current study presents a detailed description of bovine chordae tendineae formation and bifurcation during fetal development. Analysis of Movat Pentachrome-stained histological sections of the developing mitral valve apparatus was accompanied by micro-CT imaging. TEM imaging of chordae branches and common trunks allowed the measurement of collagen fibril diameter distributions. We observed a proteoglycan-rich "transition zone" at the junction between the fetal mitral valve anterior leaflet and chordae tendineae with "perforations" lined by MMP1/2 and Ki-67 expressing endothelial cells. This region also contained clusters of proliferating endothelial cells within the bulk of the tissue. We hypothesize this zone marks a region where chordae tendineae bifurcate during fetal development. In particular, perforations created by localized MMP activity serve as a site for the initiation of a "split" of a single chordae attachment into two. This is supported by TEM results that suggest a similar population of collagen fibrils runs from the branches into a common trunk. A clear understanding of normal mitral valvulogenesis and its signaling mechanisms will be crucial in developing therapeutics and/or tissue-engineered valve replacements.

Mitral Annular Disjunction in Heritable Thoracic Aortic Disease: Insights From the Montalcino Aortic Consortium.

Mitral annular disjunction (MAD), posterior displacement of the mitral valve leaflet hinge point, predisposes to arrhythmias or sudden cardiac death. We evaluated the burden of MAD, mitral valve prolapse (MVP), and mitral regurgitation (MR) by heritable thoracic aortic disease gene in a cross-sectional analysis of 2014-2023 data in the Montalcino Aortic Consortium registry. MAD was determined by direct measurement of echocardiographic images. MR and MVP were defined according to current clinical guidelines. Associations were evaluated using χ2 or Fisher exact tests. MR and MVP were enriched in Montalcino Aortic Consortium participants (672) with pathogenic variants (PV) in transforming growth factor-β pathway genes. The combination of MR and MVP was associated with mitral surgery and arrhythmias. In the subgroup with available images, MAD was enriched in SMAD3 PV compared with other transforming growth factor-β PV (prevalence ratio 1.8 [1.1-2.8], P <0.02). Severe disjunction (>10 mm) was only observed in the transforming growth factor-β subgroup and was further enriched in participants with SMAD3 PV (prevalence ratio 3.1 [1.1-8.6]). MVP (prevalence ratio 5.2 [3.0-9.0]) and MR (PR 2.7 [1.8-3.9]) were increased in participants with MAD, but MAD was not independently associated with adverse cardiac or aortic events. Pathological mitral valve phenotypes are more prevalent in individuals with PV in transforming growth factor-β pathway genes, particularly SMAD3. MR and MVP but not MAD are associated with adverse aortic and cardiac events. Because congenital mitral disease may be the primary presenting feature of SMAD3 PV, genetic testing for heritable thoracic aortic disease should be considered for such individuals, especially if they also have a family history of heritable thoracic aortic disease.

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

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

The effect of pulmonary hypertension and right ventricular dysfunction on early mortality and morbidity in patients undergoing mitral valve replacement

IntroductionThe indications for concominant tricuspid valve surgery in patients undergoing mitral valve surgery for rheumatic reasons are limited. The aim of our study was to investigate the effects of severe pulmonary hypertension and low TAPSE values on early-term mortality and morbidity in patients undergoing mitral valve replacement.MethodsThe data of all patients who underwent mitral valve replacement between January 2013 and August 2020 were examined retrospectively. Patients were divided into 2 groups according to pulmonary artery pressure (PAP ≥ 50 and PAP < 50). The group with PAP > 50 was then divided into 2 subgroups according to TAPSE (1.5 ≥ or < 1.5) values. The early-term mortality and morbidity rates of these groups were compared.ResultsSeventy-nine patients who underwent mitral valve replacement were included in the study. Fifty-four (68%) of them were female, and 25 (32%) were male. During the preoperative period, the TAPSE was 16.8 ± 3.0 mm, and the PAP was 52.1 ± 14.1 mmHg. There were 53 patients with PAP > 50 and 26 patients with PAP < 50. In the PAP > 50 group, the rates of tricuspid regurgitation (p < 0.001), blood transfusion (p < 0.001), intensive care unit stay (p < 0.001), need for CPAP (p = 0.043), reintubation (p = 0.048), acute renal failure (p = 0.028), and mortality (p = 0.026) were found to be significantly different.ConclusionIn conclusion, we believe that in patients with mitral valve pathology, early referral for surgical intervention, before the pulmonary pressures significantly increase and right ventricular function deteriorates, can enhance survival outcomes.

Long-term outcomes of mitral valve repair in children.

Mitral Valve Disease in children presents unique challenges due to the wide range of associated pathologies and the complexities of pediatric cardiac anatomy. Mitral valve repair in this demographic is preferred over replacement due to the drawbacks associated with prosthetic valves in young patients, such as the need for long-term anticoagulation and issues with prosthetic size and growth. This retrospective study reviewed pediatric patients under 18 years who underwent mitral valve repair between January 2002 and December 2023. Exclusion criteria included patients with atrioventricular septal defects or single-ventricle physiology. Surgical outcomes were assessed using preoperative and postoperative transthoracic echocardiography, with follow-up data analyzed via Kaplan-Meier survival estimates. The study included 47 patients with a median age of 4 years. Surgical techniques varied based on the specific mitral valve pathology. The overall early mortality was 6.3%, and the one and ten-year survival rates were 93.6 ± 3.6% and 91.4 ± 4.1%, respectively. Most patients showed improved or stable postoperative cardiac function during a median follow-up of 105 months. Notably, the rate of freedom from re-operation at ten years was 85.1 ± 6.9%, highlighting the durability of the surgical interventions. Mitral valve repair in children demonstrates favorable long-term outcomes with low mortality and reoperation rates, particularly when performed at an older age to accommodate growth and avoid the complexities of smaller, more delicate cardiac structures. These findings suggest that mitral valve repair should be considered a viable and effective option for managing pediatric MVD, with a personalized approach essential for optimizing outcomes.

Mitral annular disjunction as the cause of malignant ventricular arrhythmia in a young adult: a case report

Mitral annular disjunction (MAD) is associated with ventricular arrhythmias and sudden cardiac death (VA/SCD). Risk prediction for VA/SCD in individuals with MAD includes clinical, ECG and imaging markers. Imaging assessment for MAD includes transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMRI) and there are certain features in each modality to aid both diagnosis and risk assessment. A 23-year-old female with no medical history presented to hospital following out of hospital cardiac arrest. Effective bystander CPR and successful cardioversion from ventricular fibrillation to sinus rhythm by paramedics achieved return of spontaneous circulation. Focused transthoracic echocardiography and cardiac magnetic resonance imaging identified MAD. Notably, there were no specific high risk clinical or imaging features. The patient recovered completely and was discharged with implantable defibrillator for secondary prevention. MAD is a rare cause of VA/SCD. Arrhythmias secondary to MAD are more likely with abnormalities on cardiac imaging, including late gadolinium enhancement, fibrosis of the mitral annulus or papillary muscles, mitral valve pathology and ventricular ectopic beats. In this case, none of the traditional risk factors for VA/SCD were present. Thus, MAD remains an important differential in all patients with an otherwise unexplained cardiac arrest, even if high risk features are not present.

On-demand mitral valve morphometrics during surgical repair

Abstract Mitral valve regurgitation is one of the most common heart valve diseases that can occur when the structural composition of the mitral valve is affected. Mitral valve repair, typically performed in a minimally invasive setting, is a complex surgery that aims to reinstate the structural integrity of the valve and thereby restore normal valve function. The current practice lacks quantification of geometrical changes and interactive 3D visualization that could enhance the understanding of pathomorphological changes and impact of surgical correction. This work presents functionalities from smartMVR, a quantitative tool to measure, compare, and analyse changes in mitral valve geometry from data captured on-demand using an RGB-D camera. The feasibility of the approach is demonstrated on a silicone replica of a pathological mitral valve that is iteratively corrected using common surgical techniques.

Significance of Fibrillin-1, Filamin A, MMP2 and SOX9 in Mitral Valve Pathology.

Genetic factors play a significant role in the pathogenesis of mitral valve diseases, including mitral valve prolapse (MVP) and mitral valve regurgitation. Genes like Fibrillin-1 (FBN1), Filamin A (FLNA), matrix metalloproteinase 2 (MMP2), and SRY-box transcription factor 9 (SOX9) are known to influence mitral valve pathology but knowledge of the exact mechanism is far from clear. Data regarding serum parameters, transesophageal echocardiography, and genetic and histopathologic parameters were investigated in 54 patients who underwent cardiovascular surgery for mitral valve regurgitation. The possible association between Fibrillin-1, Filamin A, MMP2, and SOX9 gene expressions was checked in relationship with the parameters of systemic inflammatory response. The mRNA expression levels (RQ-relative quantification) were categorized into three distinct groups: low (RQ < 1), medium/normal (RQ = 1-2), and high (RQ > 2). Severe fibrosis of the mitral valve was reflected by high expression of FBN1 and low expression of MMP2 (p < 0.05). The myxoid degeneration level was associated with the mRNA expression level for FBN1 and a low lymphocyte-monocyte ratio was associated with an increased mRNA expression of FBN1 (p < 0.05). A high number of monocytes was associated with high values of FBN1 whereas the increase in the number of lymphocytes was associated with high levels of MMP2. In addition, we observed that the risk of severe hyalinization was enhanced by a low mRNA expression of FLNA and/or SOX9. In conclusion, a lower FLNA mRNA expression can reflect the aging process that is highlighted in mitral valve pathology as a higher risk for hyalinization, especially in males, that might be prevented by upregulation of the SOX9 gene. FBN1 and MMP2 influence the inflammation-related fibrotic degeneration of the mitral valve. Understanding the genetic base of mitral valve pathology can provide insights into disease mechanisms, risk stratification, and potential therapeutic targets.

Hypothermic Ventricular Fibrillation in Redo Minimally Invasive Mitral Valve Surgery: A Promising Solution for a Surgical Challenge.

Background: Minimally invasive mitral valve surgery (MIMVS) is a treatment for severe mitral valve pathologies. In redo cases, especially after coronary artery bypass grafting (CABG) surgery with patent mammary bypass grafts, establishing aortic clamping followed by antegrade cardioplegia application might be challenging. Here, we present the outcome of hypothermic ventricular fibrillation as an alternative to conventional cardioprotection. Methods: Patients who underwent MIMVS either received hypothermic ventricular fibrillation (study group, n = 48) or antegrade cardioprotection (control group, n = 840) and were observed for 30 postoperative days. Data were retrospectively analyzed and collected from January 2011 until December 2022. Results: Patients in the study group had a higher preoperative prevalence of renal insufficiency (p = 0.001), extracardiac arteriopathy (p = 0.001), insulin-dependent diabetes mellitus (p = 0.001) and chronic lung disease (p = 0.036). Furthermore, they had a longer surgery time and a lower repair rate (p < 0.001). No difference, however, was seen in postoperative incidences of stroke (p = 0.26), myocardial infarction (p = 1) and mitral valve re-operation (p = 1) as well as 30-day mortality (p = 0.1) and postoperative mitral valve insufficiency or stenosis. Conclusions: The patients who underwent redo MIMVS with hypothermic ventricular fibrillation did not have worse outcomes or more serious adverse events compared to the patients who received routine conventional cardioprotection. Therefore, the use of hypothermic ventricular fibrillation appears to be a promising cardioprotective technique in this challenging patient population requiring redo MIMVS.

Accuracy Of ECG-gated Computed Tomography Compared To Transthoracic And Transesophageal Echocardiography For Identifying Mitral Valve Pathology

Accuracy Of ECG-gated Computed Tomography Compared To Transthoracic And Transesophageal Echocardiography For Identifying Mitral Valve Pathology

Left atrial strain analysis in the realm of pediatric cardiology: Advantages and implications.

Left atrial (LA) strain analysis has emerged as a noninvasive technique for assessing LA function and early detection of myocardial deformation. Recently, its application has also shown promise in the pediatric population, spanning diverse cardiac conditions that demand accurate and sensitive diagnostic measures. This research article endeavors to explore the role of LA strain parameters and contribute to the growing body of knowledge in pediatric cardiology, paving the way for more effective and tailored approaches to patient care. A comprehensive literature review was conducted to gather evidence from studies using echocardiographic strain imaging techniques across pediatric populations. LA strain parameters exhibited greater sensitivity than conventional atrial function indicators, with early detection of diastolic dysfunction and LA remodeling in pediatric cardiomyopathy, children with multisystem inflammatory syndrome, rheumatic heart disease, as well as childhood renal insufficiency and obesity offering prognostic relevance as potential markers in these pediatric subpopulations. However, there remains a paucity of evidence concerning pediatric mitral valve pathology, justifying further exploration. LA strain analysis carries crucial clinical and prognostic implications in pediatric cardiac conditions, with reliable accuracy and sensitivity to early functional changes.

Percutaneous Tricuspid Valve Repair: The Triclip.

Tricuspid regurgitation is an often overlooked, but severe cardiac valvular disease associated with significant morbidity and poor quality of life. Tricuspid valve surgery is the only treatment that prevents progression of the disease but is often complicated or made impossible by perioperative risk factors. Due to the high-risk nature, tricuspid valve surgery is typically only done for severe tricuspid regurgitation at the time of left heart surgery, leaving many patients untreated. Medical therapy is limited primarily to diuretic agents, which are often unsuccessful in alleviating symptoms. Treatment of tricuspid regurgitation with transcatheter edge-to-edge repair has emerged after the success of this technique in mitral valve pathologies. This percutaneous procedure parallels surgical principles previously used for valve repair but eliminates the need for cardiac surgery, thus having the potential to serve as an alternative treatment in high-risk patients. The TriClip (Abbott Labs) device is an example of this therapy and the subject of this review.

Early and mid-term outcomes of minimally invasive mitral valve surgery in high operative risk patients at University Medical Center, Ho Chi Minh City

Introduction: Minimally invasive mitral valve surgery (MIMVS) has seen significant advancement in the past decades, offering numerous benefits to patients. However, there remain cohorts of patients with mitral valve pathologies, deemed at higher surgical risk, who may face rejection for MIMVS due to concerns regarding potential postoperative complications associated with this approach. Objective: To assess early and midterm outcomes of MIMVS in higher-operative-risk patients at the University Medical Center of Ho Chi Minh City. Methods: A retrospective descriptive study of the patients meeting our high operative risk criteria, who underwent mitral valve surgery at the University Medical Center of Ho Chi Minh City from January 2017 to March 2023. Results: A total of 68 eligible cases were included in our study. The male-to-female ratio was 0.6:1. Among these cases, 21 patients underwent valve repair and 47 others underwent mitral valve replacement. 30.9% of cases presented with NYHA class III or above heart failure. The mean cardiopulmonary circulation time and aortic cross-clamp time were 157.4 ± 38.8 minutes and 102.7 ± 26.3 minutes, respectively. Three cases experienced minimally invasive surgery related complications, including one case of limb ischemia requiring fasciotomy, one case of femoral wound seroma, and one case of postoperative wound infection necessitating debridement. No instances of conversion to sternotomy or in-hospital mortality were observed. The mean ICU stay and postoperative length of stay at ward were 4.6 ± 3.5 days and 10.8 ± 5.9 days, respectively. Patients showed rapid recovery during the postoperative period. During ICU care, one patient suffered a non-disabling cerebrovascular accident, one case required continuous renal replacement therapy, three cases necessitated intra-aortic balloon pump placement, and three cases required reoperation due to hemorrhagic pleural effusion. During follow-up period, three patients died within 6 months, and another patient died after their surgery one year. Other patients had favorable outcomes at the time of discharge and at subsequent follow-up. Conclusion: Minimally invasive mitral valve surgeries highlight the feasibility and safety of minimally mitral valve surgery in higher-operative-risk patients.

Frequency of Coronary Artery Disease in Patients Undergoing Valvular Heart Surgery: A Retrospective Observational Study

Objectives: Valvular heart disease (VHD) significantly impacts patients' lives and often necessitates cardiac surgery. This study aimed to assess the frequency of ischemic heart disease in patients undergoing valvular heart surgery. Methodology: This observational study analyzed the records of 204 consecutive patients presenting to the Peshawar Institute of Cardiology between January 2021 and December 2022. All patients underwent screening angiography before surgery according to the American College of Cardiology (ACC) criteria. Results: Among the 204 patients studied, 57.4% were male, with a mean age of 53.16 ± 12.708 years. Hypertension was the most common comorbid condition (38.2%). Mitral valve pathology was the predominant indication for valvular surgery, while isolated aortic stenosis was the most common valvular lesion observed (25%). Out of the 204 patients who underwent screening angiography, 23% had significant coronary artery disease (CAD), defined as luminal narrowing &gt;50%. Patients younger than 40 years had a lower prevalence of significant CAD (9.8%) compared to older patients (p = 0.003). Angiographic findings revealed single-vessel disease as the most common coronary lesion (16.7%), followed by double-vessel disease (12.7%), with triple-vessel disease observed in 5.4% of cases. Conclusion: The frequency of coronary artery disease was lower in patients younger than 40 years compared to older patients. Noninvasive investigations such as CT coronary angiography may serve as an alternative to invasive coronary angiography as a screening tool prior to cardiac surgery in older patients, if needed.

Differential Development of the Chordae Tendineae and Anterior Leaflet of the Bovine Mitral Valve.

There is increasing evidence that some adult mitral valve pathologies may have developmental origins involving errors in cell signaling and protein deposition during valvulogenesis. While early and late gestational stages are well-documented in zebrafish, chicks, and small mammalian models, longitudinal studies in large mammals with a similar gestational period to humans are lacking. Further, the mechanism of chordae tendineae formation and multiplication remains unclear. The current study presents a comprehensive examination of mitral anterior leaflet and chordae tendineae development in a bovine model (a large mammal with the same gestational period as humans). Remarkably distinct from small mammals, bovine development displayed early branched chordae, with increasing attachments only until birth, while the anterior leaflet grew both during gestation and postnatally. Chordae also exhibited accelerated collagen deposition, maturation, and crimp development during gestation. These findings suggest that the bovine anterior leaflet and chordae tendineae possess unique processes of development despite being a continuous collagenous structure and could provide greater insight into human valve development.

Early outcomes of transapical mitral valve implantation versus surgical replacement in matched elderly patients at intermediate surgical risk.

Data comparing transcatheter mitral valve implantation (TMVI) with surgical mitral valve replacement (SMVR) are lacking. This study sought to compare the 30-day Valve Academic Research Consortium (VARC)-3 device success of TMVI with that of SMVR. Matching protocol combined exact matching (sex, atrial fibrillation, previous surgical aortic valve replacement [SAVR] or coronary artery bypass grafting [CABG]), coarsened exact matching (age) and propensity score matching (body mass index, mitral valve pathology and concomitant tricuspid regurgitation). A total of 40 Tendyne TMVI and 80 SMVR patients with similar baseline characteristics were analysed (TMVI vs SMVR): age (78 years [interquartile range [{IQR} 75; 80] vs 78 years [IQR 73; 80]; p=0.8), female (60% vs 60%; p=1.0), atrial fibrillation (67.5% vs 63.7%; p=0.8), previous SAVR (12.5% vs 10.0%; p=0.8), previous CABG (20.0% vs 16.2%; p=0.8), body mass index (25.54 kg/m² vs 25.24 kg/m²; p=0.7) and valve pathology (mitral regurgitation: 70.0% vs 73.8%, mitral stenosis: 7.5% vs 3.8%, and mixed disease: 22.5% vs 22.5%; p=0.6). Most baseline characteristics not included in the matching model were balanced among the TMVI/SMVR cohorts: European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (5.8% [IQR 2.9; 7.5] vs 4.2% [IQR 2.4; 6.8]; p=0.3) and Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score (5.2% [IQR 3.2; 8.6] vs 4.1% [IQR 3.3; 6.1]; p=0.076). Coronary artery disease (67.5% vs 32.5%; p<0.001) and previous percutaneous coronary intervention (47.5% vs 25.0%; p=0.023) differed among groups. Mitral VARC (MVARC) device success at 30 days was achieved in 82.5% of patients after TMVI and 57.5% of patients after SMVR (p=0.04). MVARC procedural success at 30 days was 75.0% after TMVI versus 52.5% after SMVR (p=0.07). Thirty-day mortality (2.5% vs 3.8%; p=0.47), technical success (97.5% vs 97.5%; p=1.0), major bleeding (17.5% vs 18.7%; p=0.087), stroke (5.0% vs 4.9%; p=1.0) and postoperative haemodialysis (7.5% vs 5.2%; p=0.4) were similar in both groups. Patients with intermediate surgical risk, according to STS-PROM and EuroSCORE II, demonstrated higher rates of MVARC device at 30 days after TMVI compared to 30 days after SMVR. Rates of survival and procedural success, neurological, renal and bleeding complications were similar. Transfusion count and length of stay were lower after TMVI. For elderly patients at intermediate risk, a TMVI eligibility assessment may be considered.

Transcatheter Mitral Valve-in-valve Implantation with the Balloon-expandable Myval Device

For mitral valve pathologies like mitral stenosis and mitral regurgitation various treatment options are currently available. However, in patients who have previously operated on mitral valves only a few options are applicable. In this case report, we provide detailed insight into transcatheter mitral valve-in-valve implant in a patient with a degenerated surgically implanted mitral bioprosthetic valve.

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).

Hypertrophic Cardiomyopathy With Elongated Mitral Valve Leaflets: Clinical Characteristics and Surgical Results

Background: Hypertrophic cardiomyopathy (HCM) is commonly associated with mitral valve pathology. A large majority of patients with HCM have elongated anterior and posterior mitral leaflets. There remains debate regarding the necessity and role of concomitant mitral valve surgery at the time of septal myectomy. We aimed to describe the characteristics and share our surgical experiences with this specific group of patients.Methods: This retrospective single‐center study investigates adult patients with HCM, with or without elongated mitral valve leaflets (MVLs), who underwent elective septal myectomy with or without concomitant mitral valve intervention, between January 1, 2016, and June 30, 2020. Clinical data were obtained from institutional medical records as well as the Society of Thoracic Surgeons data registry. The clinical characteristics and in‐hospital surgical outcomes were compared between patients with an elongated MVL and those without.Results: In total, 379 patients underwent septal myectomy, and 22 patients with intrinsic mitral valve disease were excluded. In addition, 23 patients were excluded due to missing data. Of the remaining 334 patients, 131 (39.2%) had elongated MVL and concomitant MVL plication. Patients with elongated MVL had higher rates of preoperative mitral valve systolic anterior motion (SAM) (94.7% vs. 86.7%, p = 0.019) and higher preoperative provoked left ventricular outflow tract gradient (LVOTG) (134.5 mmHg versus 125.3 mmHg, p = 0.046). Post septal myectomy and mitral valve plication, they had lower rates of postoperative residual mitral regurgitation (3.8% vs. 12.8%, p = 0.006), comparable rates of residual SAM (28.2% vs. 31.5%, p = 0.524), postoperative provoked LVOTG (15.4 mmHg vs. 14.0 mmHg, p = 0.317), 30‐day major adverse cardiopulmonary events (2.3% vs. 3.9%, p = 0.409), and mortality (0% vs. 1.0%, p = 0.255).Conclusions: Elongated MVLs contribute more significantly to dynamic LVOT obstruction, as evidenced during provocative testing. Concomitant mitral valve intervention during septal myectomy can be performed safely and may provide an effective strategy to resolve SAM and stress‐induced LVOTG.

Mitral Valve Culture Negative Endocarditis Complicated by Severe Mitral Regurgitation and Chordae Tendinea Rupture

Infective endocarditis has a high mortality rate. Criterion for diagnosis is a positive blood culture, however, some cases present with negative blood culture. We present a 65-year-old male complaining of palpitations. EKG showed atrial fibrillation with RVR. Transthoracic echocardiogram showed severe mitral regurgitation and possible vegetation. Transesophageal echocardiogram revealed endocarditis with ruptured chordae and vegetation on the posterior leaflet. All obtained blood cultures remained negative. Cardiothoracic surgery and infectious disease specialties were consulted. Patient was started on broad spectrum antibiotics. Patient underwent a mitral valve replacement and pathology showed focal myxoid degeneration with no inflammation and cultures of the specimen were negative. The hospital course was complicated by hemopericardium, treated by pericardial window, and drain placement. The patient was ultimately discharged to an acute rehabilitation center. Culture-negative endocarditis presents a diagnostic and therapeutic dilemma for clinicians and should be promptly identified and treated to avoid complications.