Clinical characteristics and long-term outcome of patients with bioprosthetic mitral valve- Experience from a South Asian country.

Objectives: Due to rheumatic heart disease, young people are more likely to develop valvular heart disease in developing countries. In countries like Pakistan, surgeons implant more bioprosthetic mitral valves (MVs) in younger patients. However, bioprosthetic valves degenerate rapidly in younger people, leading to bioprosthetic MV dysfunction (BMVD). This study aims to evaluate the clinical characteristics and long-term outcomes of patients with bioprosthetic MV replacement (MVR) at a tertiary care hospital in a South Asian country. Material and Methods: This is a retrospective observational study, conducted at a tertiary care hospital. We included a total of 502 patients who underwent bioprosthetic MVR from the year 2006 to 2020. Clinical and surgical characteristics along with transthoracic echocardiographic findings (pre-surgery and recent most follow-up studies) were noted. Follow-up data were also collected. Results: Out of 502 patients, 322 (64%) were female, mean age at the time of surgery was 49.42 ± 14.56 years. Mitral regurgitation was more common, found in 279 (55.6%) patients followed by mitral stenosis in 188 (37.5%) patients. MVR was done as an elective procedure due to the New York Heart Association (NYHA) II to IV symptoms at the time of surgery in 446 (88.8%) patients. In the mean follow-up of 6.59 ± 2.99 years, BMVD was observed in 183 (36.5%) patients. However, re-do MV surgery was done in only 49 (9.8%) patients. Patients were divided into two groups based on normal functioning bioprosthetic MV and BMVD. Comparing the two groups, individuals with normal functioning bioprosthetic MV had a mean age of 51.6 ± 14.27 years, while those with BMVD had a mean age of 45.639 ± 14.33 years at the time of index surgery (P = 0.000). There were more long-term complications including heart failure (n = 16, 8.74%), atrial fibrillation (n = 11, 6.01%), and death (n = 6, 3.28%) in the BMVD group which were statistically significant. Conclusion: This study is distinct because it demonstrates the outcomes of bioprosthetic valve replacement in a relatively younger South Asian population. Due to rapid degeneration of bioprosthetic valve in younger patients, significant number of patients developed BMVD along with poor long-term clinical outcomes, even at a short follow-up period of <10 years. These findings are similar to international data and signify that mechanical MVR may be a more reasonable alternative in younger patients.

Left and Right Ventricular Hemodynamic Response After Transcatheter Mitral Valve Replacement.

Background: Transcatheter mitral valve replacement (TMVR) represents a novel treatment option for patients with mitral regurgitation (MR), but little is known about the hemodynamic impact of MR elimination following TMVR. We sought to investigate the hemodynamic impact of TMVR on left ventricular (LV) and right ventricular (RV) function using noninvasive pressure-volume loops. Methods: All consecutive patients undergoing TMVR with dedicated devices between May 2016 and August 2022 were enrolled. The end-diastolic and end-systolic pressure-volume relationships were estimated from 26 patients using single-beat echocardiographic measurements at baseline and after TMVR at discharge. RV function was assessed by RV-pulmonary artery (PA) coupling and RV fractional area change. One-year follow-up was available for 19 patients. The prognostic impact of calculated end-diastolic volume at an end-diastolic pressure of 20 mmHg (VPed20) reduction was assessed by Cox regression. Results: A total of 26 patients (77.0 years [interquartile range 73.9-80.1], N = 17 [65.4%] male) with successful TMVR were included (secondary MR [N = 21, 80.8%]; median LV ejection fraction was 37.0% [interquartile range 30.7-50.7]). At discharge, a decrease in VPed20 (p < 0.001) indicating leftward shift of end-diastolic pressure-volume relationship, and an increase of the end-systolic elastance slope (p = 0.007) were observed after TMVR. No changes were observed for RV-PA coupling (p = 0.19) and RV fractional area change (p = 0.22). At 1-year follow-up, LV contractility (end-systolic elastance) and RV-PA coupling remained stable. Vped20 reduction at discharge was significantly associated with 1-year all-cause mortality or heart failure hospitalization (hazard ratio 0.16, 95% CI 0.04-0.71, p = 0.016). Conclusions: Noninvasive assessment of pressure-volume loops demonstrated early LV reverse remodeling and improved LV contractility, while RV performance was preserved. These results indicate the potential prognostic impact of complete MR elimination after TMVR.

Simultaneous Transcatheter Aortic and Mitral Native Valve Replacement: A Step-by-Step Procedural Approach.

Multivalvular heart disease (MVHD) is present in one-third of patients with valvular heart disease (VHD). Compared to single VHD patients, these patients have a more significant hemodynamic impact and are often left under medical treatment. Most importantly, when undergoing multiple valve interventions, they show worse rates of heart failure and mortality. The guidelines-supported interventions in patients with MVHD in combined aortic regurgitation and mitral stenosis include percutaneous mitral balloon commissurotomy, open mitral commissurotomy, or surgical mitral valve replacement followed by transcatheter or surgical aortic valve replacement, trying to minimize the increased mortality risk of double-valve replacement. Simultaneous transcatheter valve replacement (STVR) for native MVHD is still off-label and not yet considered in clinical guidelines since the evidence of its results is limited to a few cases reported worldwide. However, fully percutaneous transfemoral STVR seems promising for MVHD patients thanks to its minimal invasiveness, the continuous improvement of the transcatheter heart valve devices, the likely shorter length of stay and the fastest recovery. To our knowledge, this is the first case ever reported of fully percutaneous STVR for native MVHD in aortic regurgitation and mitral stenosis. Deep understanding of both pathologies and their interactions, not only from a pathological point of view but from the procedural planning and procedural steps point of view is mandatory. Hereby we present the specific STVR procedural planning considerations, a step-by-step guide on how to perform an aortic and mitral STVR and its critical considerations, as well as the procedural and follow-up results.

Left Ventricular Outflow Tract and Transcatheter Mitral Valve Replacement Obstruction and TMVR: Predictors, Evaluation, and Solutions.

In this issue of Structural Heart, high-impact presentations from Transcatheter Valve Therapies 2023 are reviewed. Dr Jaffar Khan provided updates on the current understanding of left ventricular outflow tract obstruction in the field of transcatheter mitral valve replacement, highlighting known predictors of obstruction, a generally agreed-upon strategy for preprocedure assessment, and a host of management strategies in various stages of development and study.

An Unusual Presentation of Acute Severe Mitral Regurgitation.

Mitral regurgitation (MR) results from retrograde blood flow from the left ventricle to the left atrium. Common etiologies of acute severe MR include papillary muscle rupture from myocardial infarction, leaflet perforation in infective endocarditis, chordal rupture (pop) in myxomatous valve disease, acute rheumatic fever with carditis, or functional MR due to cardiomyopathies, myocarditis or Takotsubo cardiomyopathy. Here, we present an unusual case of acute severe MR due to ruptured chordae tendineae likely secondary to degenerative valve disease. A 59-year-old male with a past medical history of hypertension and renal calculi was evaluated in the outpatient office for a urologic procedure. He was sent to the emergency room with left-sided chest pain, 6/10 in intensity, burning in nature, and non-radiating with no aggravating and relieving factors. He had nausea and vomiting for the past three days. He reported similar chest pain at rest and on exertion multiple times over the past year. He also had a chronic cough with no recent changes. His examination was unremarkable. Chest X-ray showed interstitial lung markings. Electrocardiography revealed an old right bundle branch block, but no ST/T-wave changes. He was admitted and treated for atypical pneumonia with ceftriaxone and azithromycin. The following morning, he complained of persistent chest pain 9/10 in intensity which improved with nitroglycerin. His examination revealed a new onset holosystolic murmur heard over the precordium. A two-dimensional echocardiogram showed a preserved ejection fraction of 55-60%, severe MR with eccentric jet, concerning for partially flail leaflet of the mitral valve. He was transferred to the university hospital for mitral valve replacement. Patients with acute rupture of chordae tendineae usually progress to severe mitral valve regurgitation. These patients usually present with pulmonary edema, signs of heart failure, and cardiogenic shock. Papillary muscle dysfunction, as well as partial or complete rupture of the mitral chordae can be detected as a new-onset holosystolic murmur and can be a crucial sign for early recognition. In our case, the patient developed a new holosystolic murmur on day two of admission which was recognized early, and prompt surgical intervention was performed.

Pseudomonas aeruginosa Endocarditis With a Large Mitral Valve Vegetation Causing Severe Mitral Valve Regurgitation and Cardiogenic Shock.

Infective endocarditis (IE) is characterized by the inflammation of the inner layer of the heart that can be caused by different pathogens. Pseudomonas aeruginosa is an uncommon source of IE. The clinical presentation is highly dependent on the patient's medical history, societal factors, and valve involvement. This infection is associated with many unfavorable complications and high mortality rates. We present a case of P. aeruginosa endocarditis causing severe mitral valve regurgitation, leading to cardiogenic shock and an eventual replacement of the mitral valve. Prompt and sensitive antibiotics in combination with surgical consultation are vital to the survival of this condition.

Long-term outcomes following mitral valve replacement in children at heart center Leipzig: a 20-year analysis.

BACKGROUND: Although mitral valve repair is the preferred surgical strategy in children with mitral valve disease, there are cases of irreparable severe dysplastic valves that require mitral valve replacement. The aim of this study is to analyze long-term outcomes following mitral valve replacement in children in a tertiary referral center. METHODS: A total of 41 consecutive patients underwent mitral valve replacement between February 2001 and February 2021. The study data was prospectively collected and retrospectively analyzed. Primary outcomes were in-hospital mortality, long-term survival, and long-term freedom from reoperation. RESULTS: Median age at operation was 23 months (IQR 5-93), median weight was 11.3 kg (IQR 4.8-19.4 kg). One (2.4%) patient died within the first 30 postoperative days. In-hospital mortality was 4.9%. Four (9.8%) patients required re-exploration for bleeding, and 2 (4.9%) patients needed extracorporeal life support. Median follow-up was 11 years (IQR 11 months - 16 years). Long-term freedom from re-operation after 1, 5, 10 and 15 years was 97.1%, 93.7%, 61.8% and 42.5%, respectively. Long-term survival after 1, 5, 10 and 15 years was 89.9%, 87%, 87% and 80.8%, respectively. CONCLUSION: If MV repair is not feasible, MV replacement offers a good surgical alternative for pediatric patients with MV disease. It provides good early- and long-term outcomes.

Transcatheter Treatment Options for Functional Mitral Regurgitation: Which Device for Which Patients?

Mitral regurgitation is the most common valvular disease in the developed world, with approximately 24.2 million people being affected worldwide and a higher prevalence in older age groups. Surgical correction of degenerative mitral regurgitation is the standard of care and can restore cardiac function and provide a lasting result, especially when the mitral valve can be repaired. Secondary mitral regurgitation, or functional mitral regurgitation (FMR), describes atrial or ventricular factors leading to poor coaptation of an otherwise non-diseased valve. For FMR, traditional surgery has not produced the same level of benefit. Transcatheter mitral repair and replacement techniques that mimic surgical correction are under investigation. Transcatheter edge-to-edge repair is the only approved catheter-based therapy for FMR in the US. Here, the transcatheter treatment options for FMR are reviewed.

The Role of Microbes in Surgical Decision Making for Infective Endocarditis: Mitral Valve Repair or Replacement?

BACKGROUND: The benefits of mitral repair versus replacement for endocarditis are inconclusive. This study compares outcomes of patients with infective endocarditis undergoing mitral valve repair versus replacement and investigates the impact of microbial etiology. METHODS: All 251 patients undergoing mitral valve surgery for active endocarditis between 2010 and 2023 were enrolled, 180 (71.7%) replacement and 71 (28.3%) repair. To adjust for imbalances, inverse probability of treatment weighting was applied and 187 patients were obtained. RESULTS: The analysis between groups, following the application of inverse probability of treatment weighting, showed no statistically significant differences across all considered outcomes. Early and late death was observed respectively in 6 (8.5%) and 11 (15.5%) patients in the repair group versus 24 (13.3%) and 45 (25.0%) in the replacement group without statistical significance (p = 0.221 and p = 0.446). Relapse occurred in six patients (8.5%) in the repair group after a median time of 4.0 months and in six (3.3%) in the replacement after 6.9 months (p = 0.071). CONCLUSIONS: Surgical strategy in mitral endocarditis has no effect on major postoperative complications, mortality, or medium/long-term survival. Staphylococcus aureus and Coagulase-negative Staphylococci represent a risk for early mortality and relapse. However, mitral valve repair for endocarditis can be pursued when it ensures the complete eradication of all infected tissue, particularly in cases caused by Streptococcus infection, in young patients, and after a minimum of 18 days of antibiotic therapy.

Emerging Transcatheter Therapies for Valvular Heart Disease: Focus on Mitral and Tricuspid Valve Procedures.

The emergence of percutaneous treatment options provides novel therapeutic alternatives for older and feeble patients who are at high risk for any surgical procedure. The purpose of our review was to offer an up-to-date analysis of the rapidly expanding field of percutaneous technologies for mitral, tricuspid, and pulmonary procedures. Edge-to-edge repair is an established treatment for secondary mitral regurgitation (MR), while transcatheter mitral valve replacement is a potential and expanding option for managing both secondary and primary MR. However, additional advancements are necessary to enhance the safety and feasibility of this procedure. Transcatheter tricuspid intervention is an emerging option that was conceived after the success of transcatheter procedures in aortic and mitral valves, and it is currently still in the early stages of advancement. This can be attributed, at least in part, to the previously overlooked effect of tricuspid regurgitation on patient outcomes. The development of edge-to-edge repair represents the forefront of innovations in transcatheter procedures. There is a scarcity of data about tricuspid annuloplasty and replacement, and further study is necessary. Transcatheter mitral, tricuspid, and pulmonary procedures show prospects for the future, while their role in clinical practice has not been definitively established.

3-Dimensional Echocardiographic Prediction of Left Ventricular Outflow Tract Area Prior to Transcatheter Mitral Valve Replacement.

BACKGROUND: New postprocessing software facilitates 3-dimensional (3D) echocardiographic determination of mitral annular (MA) and neo-left ventricular outflow tract (neo-LVOT) dimensions in patients undergoing transcatheter mitral valve replacement (TMVR). OBJECTIVES: This study aims to test the accuracy of 3D echocardiographic analysis as compared to baseline computed tomography (CT). METHODS: A total of 105 consecutive patients who underwent TMVR at 2 tertiary care centers between October 2017 and May 2023 were retrospectively included. A virtual valve was projected in both baseline CT and 3D transesophageal echocardiography (TEE) using dedicated software. MA dimensions were measured in baseline images and neo-LVOT dimensions were measured in baseline and postprocedural images. All measurements were compared to baseline CT as a reference. The predicted neo-LVOT area was correlated with postprocedural peak LVOT gradients. RESULTS: There was no significant bias in baseline neo-LVOT prediction between both imaging modalities. TEE significantly underestimated MA area, perimeter, and medial-lateral dimension compared to CT. Both modalities significantly underestimated the actual neo-LVOT area (mean bias pre/post TEE: 25.6 mm2, limit of agreement: -92.2 mm2 to 143.3 mm2; P < 0.001; mean bias pre/post CT: 28.3 mm2, limit of agreement: -65.8 mm2 to 122.4 mm2; P = 0.046), driven by neo-LVOT underestimation in the group treated with dedicated mitral valve bioprosthesis. Both CT- and TEE-predicted-neo-LVOT areas exhibited an inverse correlation with postprocedural LVOT gradients (r2 = 0.481; P < 0.001 for TEE and r2 = 0.401; P < 0.001 for CT). CONCLUSIONS: TEE-derived analysis provides comparable results with CT-derived metrics in predicting the neo-LVOT area and peak gradient after TMVR.

Transapical transcatheter mitral valve replacement for mitral valve disease: an Iberian experience.

INTRODUCTION AND OBJECTIVES: Transcatheter mitral valve replacement (TMVR) is an emerging treatment alternative for mitral valve (MV) disease in patients who were ineligible for surgical intervention or edge-to-edge repair. This study aimed to assess the short- and mid-term outcomes of this procedure. METHODS: We conducted a prospective registry to include the initial experience with symptomatic, consecutive patients who underwent TMVR using the transapical Tendyne system at 7 centers in the Iberian Peninsula. Baseline clinical and imaging data, periprocedural information, and follow-up assessments were collected at 1 month and 1 year. RESULTS: A total of 40 patients (mean age 78.5 years [76-82], 47,5% males) underwent TMVR. The majority had significant surgical risk, comorbidities, and advanced functional class. All patients had significant mitral regurgitation (MR), except for 2 with severe stenosis. Previous MV intervention and off-label indication for the procedure were present in 4 (10.0%) and 8 (20.0%) patients, respectively. Technical success was recorded in 100%, device success in 95.0%, and procedural success in 85.0% at 30-day. All-cause mortality was 2.5% and 17.5% at the 1-month and 1-year follow-up, respectively. MR reduction (≤ 1) and functional class improvement (NYHA I-II) were observed at 1 year in 93.9% and 87.9% of survivors, respectively. CONCLUSIONS: Treatment with TMVR produced enduring resolution of MV disease and notable functional enhancement at 1 year of follow-up. The procedure demonstrated a satisfactory early safety profile, although 1-year mortality remained relatively high in this high-risk population.

Abiotrophia defectiva Endocarditis: A Case Diagnosed Incidentally Due to Multi-organ Embolism.

Abiotrophia defectiva, often referred to as nutritionally variant streptococci, is generally a benign part of human microflora, primarily found in the oral cavity, digestive tract, and genitourinary system. However, it can have a significant role in infectious endocarditis (IE). We discuss a case involving a 53-year-old male who displayed serious signs indicative of IE. The individual, who had a history of IgA nephropathy, underwent successful surgical and antibiotic intervention. Given the challenge in treating A. defectiva due to its high antibiotic resistance and the tendency for embolic events and treatment failure, a multidimensional approach involving surgical intervention and specific antibiotic therapy resulted in a successful outcome. This case underlines the need for early identification, immediate treatment, and additional research to understand better and manage A. defectiva endocarditis.

Mechanical Valves: Past, Present, and Future-A Review.

The mechanical valve was first invented in the 1950s, and since then, a wide variety of prostheses have been developed. Although mechanical valves have outstanding durability, their use necessitates life-long treatment with anticoagulants, which increases the risk of bleeding and thromboembolic events. The current guidelines recommend a mechanical prosthetic valve in patients under 50-60 years; however, for patients aged 50-70 years, the data are conflicting and there is not a clear-cut recommendation. In recent decades, progress has been made in several areas. First, the On-X mechanical valve was introduced; this valve has a lower anticoagulant requirement in the aortic position. Second, a potential alternative to vitamin K-antagonist treatment, rivaroxaban, has shown encouraging results in small-scale trials and is currently being tested in a large randomized clinical trial. Lastly, an innovative mechanical valve that eliminates the need for anticoagulant therapy is under development. We attempted to review the current literature on the subject with special emphasis on the role of mechanical valves in the current era and discuss alternatives and future innovations.

Transcatheter Versus Surgical Mitral Valve Interventions in Patients With Prior Coronary Artery Bypass Grafting.

BACKGROUND: A significant proportion of patients requiring mitral valve (MV) intervention have undergone prior coronary artery bypass grafting (CABG). Reoperative heart surgery is associated with increased risk. AIMS: To evaluate the utilization and outcomes of transcatheter versus surgical MV interventions in patients with prior CABG. METHODS: We queried the Nationwide Readmission Database (2016-2021) to identify adults with prior CABG hospitalized for transcatheter or surgical MV intervention. In-hospital outcomes were compared using multivariable regression and propensity-matching analyses. Readmissions were compared using Cox proportional hazards regression model. RESULTS: Of 305,625 weighted hospitalizations for MV intervention, 23,506 (7.7%) occurred in patients with prior CABG. From 2016-2021, the use of transcatheter MV interventions increased among patients with prior CABG (72 to 191 for repair and 6 to 45 for replacement per 100,000 hospitalizations, both ptrend<0.001). Compared with surgical MV repair and replacement, transcatheter MV repair and replacement were associated with similar in-hospital mortality (adjusted odds ratio [aOR] 0.44, 95% confidence interval [CI] 0.20-1.03 for repair; aOR 0.61, 95% CI 0.38-1.02 for replacement) and 180-day heart failure readmissions (adjusted hazard ratio [aHR] 1.56, 95% CI 0.85-2.87 for repair; aHR 1.15, 95% CI 0.63-2.09 for replacement) and lower stroke, acute kidney injury, permanent pacemaker placement, length of stay, and nonhome discharges, respectively. Vascular complications were higher with transcatheter versus surgical MV replacement. CONCLUSIONS: Transcatheter MV interventions are increasingly used as the preferred modality of MV intervention in patients with prior CABG and are associated with similar in-hospital mortality and 180-day heart failure readmissions compared with surgical MV interventions.

20 Years of triple-valve surgery in the UK: demographic and outcome trends.

OBJECTIVES: To describe evolving demographic trends and early outcomes in patients undergoing triple-valve surgery in the UK between 2000 and 2019. METHODS: We planned a retrospective analysis of national registry data including patients undergoing triple-valve surgery for all aetiologies of disease. We excluded patients in a critical preoperative state and those with missing admission dates. The study cohort was split into 5 consecutive 4-year cohorts (groups A, B, C, D and E). The primary outcome was in-hospital mortality, and secondary outcomes included prolonged admission, re-exploration for bleeding, postoperative stroke and postoperative dialysis. Binary logistic regression models were used to establish independent predictors of mortality, stroke, postoperative dialysis and re-exploration for bleeding in this high-risk cohort. RESULTS: We identified 1750 patients undergoing triple-valve surgery in the UK between 2000 and 2019. Triple valve surgery represents 3.1% of all patients in the dataset. Overall mean age of patients was 68.5 ± 12 years, having increased from 63 ±12 years in group A to 69 ± 12 years in group E (P < 0.001). Overall in-hospital mortality rate was 9%, dropping from 21% in group A to 7% in group E (P < 0.001). Overall rates of re-exploration for bleeding (11%, P = 0.308) and postoperative dialysis (11%, P = 0.066) remained high across the observed time period. Triple valve replacement, redo sternotomy and poor preoperative left ventricular ejection fraction emerged as strong independent predictors of mortality. CONCLUSIONS: Triple-valve surgery remains rare in the UK. Early postoperative outcomes for triple valve surgery have improved over time. Redo sternotomy is a significant predictor of mortality. Attempts should be made to repair the mitral and/or tricuspid valves where technically possible.

Mitral valve replacement in young patients: review and current challenges.

Mitral valve repair is the ideal intervention for mitral valve disease with excellent long-term survival comparable to the age-matched general population. When the mitral valve is not repairable, mechanical prostheses may be associated with improved survival as compared with biological prostheses. Newer mechanical and biological valve prostheses have the potential to improve outcomes following mitral valve replacement in young patients. Patients presenting for mitral valve surgery after failed transcatheter mitral valve-in-valve have high rates of postoperative mortality and morbidity, exceeding those seen with reoperative mitral valve surgery, which poses issues in young patients who have a higher cumulative incidence of reintervention.

Patients presenting with mitral valve disease, the most common type of heart valve disease, have a survival advantage when they undergo mitral valve repair as opposed to replacement, and this is particularly true for young patients. When the mitral valve is not repairable, mechanical prostheses (prosthetic implants) may be associated with improved survival as compared with biological prostheses, and this difference is mostly observed until the age of 70 years. Newer techniques of treating mitral valve disease without requiring open heart surgery have not yet been shown to be superior or even equivalent to traditional open heart surgery in the general population. Patients presenting for mitral valve surgery after failure of these newer techniques have high rates of death, exceeding those seen with mitral valve reoperation, which has important implications for young patients with mitral valve disease.

Mitral Valve Replacement for Bulky, Calcified Mitral Annulus: A Case Report.

Calcification of the mitral valve annulus is common in patients on dialysis. The growing number of individuals receiving dialysis has been accompanied by an increase in cases necessitating surgical intervention for mitral valve annulus calcification. In this report, we present a severe case characterized by bulky calcification of the mitral annulus, which was managed with mechanical mitral valve replacement. A 61-year-old man on dialysis presented with chest pain upon exertion that had persisted for 3 months. Cardiac echocardiography revealed severe mitral stenosis and regurgitation, accompanied by cardiac dysfunction. During surgery, an ultrasonic aspiration system was employed to remove the calcification of the mitral valve annulus to the necessary extent. Subsequently, a mechanical mitral valve was sutured into the supra-annular position. To address the regurgitation, the area surrounding the valve was sewn to the wall of the left atrium. Postoperative assessments indicated an absence of perivalvular leak and demonstrated improved cardiac function. The patient was discharged on postoperative day 22. We describe a successful mitral mechanical valve replacement in a case of extensive circumferential mitral annular calcification. Even with severe calcification extending into the left ventricular myocardium, we were able to minimize the decalcification process. This approach enabled the performance of mitral mechanical valve replacement in a high-risk patient on dialysis, thus expanding the possibilities for cardiac surgery.