Reoperative Mitral Surgery Versus Transcatheter Mitral Valve Replacement: A Systematic Review

Clinical and subclinical acute brain injury caused by invasive cardiovascular procedures

Over the past 50 years, the number and invasiveness of percutaneous cardiovascular procedures globally have increased substantially. However, cardiovascular interventions are inherently associated with a risk of acute brain injury, both periprocedurally and postprocedurally, which impairs medical outcomes and increases health-care costs. Current international clinical guidelines generally do not cover the area of acute brain injury related to cardiovascular invasive procedures. In this international Consensus Statement, we compile the available knowledge (including data on prevalence, pathophysiology, risk factors, clinical presentation and management) to formulate consensus recommendations on the prevention, diagnosis and treatment of acute brain injury caused by cardiovascular interventions. We also identify knowledge gaps and possible future directions in clinical research into acute brain injury related to cardiovascular interventions.

Expanding treatment horizons: transcatheter mitral valve-in-valve replacement in bridging to heart transplant

Transcatheter mitral valve (MV) replacement is an option in complex MV disease with potentially more predictable treatment outcomes and less invasiveness that increases the treatment spectrum to high-risk or non-surgical patients. We present an interesting case of failed MV bioprosthesis who presented with progressively worsening heart failure for heart transplant evaluation, but was successfully managed with transcatheter mitral valve-in-valve replacement (TMViVR). This case illustrates the pivotal role of TMViVR utilization in addressing complex cardiac scenarios, particularly when re-operative surgical MV replacement poses a high risk and also bridging the gap between the present and future heart transplantation preparations by paving the way for a well-prepared patient in the subsequent phase. The lifetime disease management and patient-centric approach with meticulous risk assessment reinforces the importance of shared decision-making in complex cases.

Valve-in-Valve Transcatheter Mitral Valve Replacement in a Very High-Risk Octagenerian Patient: A Case Report

Degeneration of the surgical bioprosthetic valves remains one of the most common complications of surgical valve replacement. Redo surgery is the gold standard, but unfortunately, most of these patients are deemed inoperable because of the high perioperative mortality. Transcatheter implantation of a new valve inside the degenerated bioprosthesis (valve-in-valve (ViV)) has emerged as an alternative solution. A 79-year-old patient with a medical history of surgical replacement of the mitral valve with a bioprosthetic valve, coronary artery bypass graft surgery (CABG) with implantation of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD), paroxysmal atrial fibrillation, and chronic kidney disease was referred to our hospital for ViV transcatheter mitral valve replacement (TMVR). He had recent hospitalizations with pulmonary edema caused by severe stenosis of the bioprosthetic valve and his perioperative mortality for a redo surgery was very high (EuroSCORE II: 13.72%). The ViV TMVR was performed with a transseptal approach and after the implantation of the new valve, the mean pressure gradient was dropped from 19.39 to 2.33 mmHg. The procedure was technically successful and the patient was discharged asymptomatic.

Trans-catheter mitral valve-in-valve replacement in a patient on venoarterial extracorporeal membrane oxygenation: a case report

Background

Bioprosthetic mitral valves on average have a median durability between 8 and 10 years. After the failure of a bioprosthetic valve, surgical replacement is often indicated. However, the options for those patients at high or prohibitive surgical risks are limited. Here, we describe a case of a successful trans-catheter mitral valve-in-valve (TMViV) replacement on venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Case summary

We describe a case of a 39-year-old female with a history notable for systemic lupus erythematosus, severe pulmonary arterial hypertension (now mixed pre and post) thought to be secondary to prior substance use, and infective endocarditis complicated by severe mitral stenosis status post-bioprosthetic mitral valve replacement who presented with symptoms of acute hypoxic respiratory failure secondary to severe bioprosthetic mitral valve stenosis. The patient had a prolonged hospital course complicated by a pulseless electrical activity arrest, (continuous renal replacement therapy) for acute renal failure, and hypertonic saline due to cerebral oedema. Due to her significant co-morbidities and haemodynamic instability with acute kidney injury and recent neurologic insult, the patient was thought not to be a good surgical candidate. However, given her young age and overall improved neurologic status, it was thought the patient could benefit from a TMViV with bi-ventricular support given her right- and left-sided heart failure and was placed on VA-ECMO in anticipation of a TMViV procedure for circulatory support. The patient underwent a successful TMViV replacement using a trans-septal approach with a 26 mm SAPIEN 3 valve and atrial septal defect closure with a 14 mm Amplatzer device on hospital Day 12. The patient was successfully de-cannulated from VA-ECMO on hospital Day 13. The patient had a prolonged hospital course but eventually had renal recovery and tracheostomy de-cannulation. A trans-thoracic echocardiogram prior to discharge was notable for a well-functioning valve and normal ejection fraction. The patient was discharged to a nursing home for further rehabilitation.

Discussion

The gold standard for bioprosthetic mitral valve stenosis is surgical replacement of the valve. However, the options for those at high or prohibitive surgical risk are lacking. Recent studies have demonstrated TMViV is a safe alternative to surgical mitral valve redo cases in high-risk patients. To our knowledge, there are limited data on trans-catheter valve placement while on VA-ECMO. Successful implantation in our patient suggests that TMViV in a stenotic bioprosthesis is feasible in very high-risk patients with the use of VA-ECMO to support haemodynamics.

Comparison of Postdischarge Outcomes Between Valve-in-Valve Transcatheter Mitral Valve Replacement and Reoperative Surgical Mitral Valve Replacement

Limited data are available comparing the postdischarge perioperative outcomes of isolated valve-in-valve transcatheter mitral valve replacement (VIV-TMVR) versus surgical reoperative mitral valve replacement (re-SMVR) on a nationwide scale. The objective of this study was to perform a robust head-to-head assessment of contemporary postdischarge outcomes between isolated VIV-TMVR and re-SMVR using a large national multicenter longitudinal database. Adult patients aged ≥18 years with failed/degenerated bioprosthetic mitral valves who underwent either isolated VIV-TMVR or re-SMVR were identified in the 2015 to 2019 Nationwide Readmissions Database. The risk-adjusted differences in 30-, 90-, and 180-day outcomes were compared using propensity score weighting with overlap weights to mimic the results of a randomized controlled trial. The differences between a transeptal and transapical VIV-TMVR approach were also compared. A total of 687 patients with VIV-TMVR and 2,047 patients with re-SMVR were included. After the overlap weighting to attain balance between treatment groups, VIV-TMVR was associated with significantly lower major morbidity within 30 (odds ratio [95% confidence interval (CI)] 0.0.31 [0.22 to 0.46]), 90 (0.34 [0.23 to 0.50]), and 180 (0.35 [0.24 to 0.51]) days. The differences in major morbidity were primarily driven by less major bleeding (0.20 [0.14 to 0.30]), new onset complete heart block (0.48 [0.28 to 0.84]) and need for permanent pacemaker placement (0.26 [0.12 to 0.55]). The differences in renal failure and stroke were not significant. VIV-TMVR was also associated with shorter index hospital stays (median difference [95% CI] -7.0 [4.9 to 9.1] days) and an increased ability for patients to be discharged home (odds ratio [95% CI] 3.35 [2.37 to 4.72]). There were no significant differences in total hospital costs; in-hospital or 30-, 90-, and 180-day mortality; or readmission. The findings remained similar when stratifying the VIV-TMVR access using a transeptal versus a transapical approach. The changes in outcomes over time suggest marked improvements for patients with VIV-TMVR relative to stagnant results for patients with re-SMVR from 2015 to 2019. In this large nationally representative cohort of patients with failed/degenerated bioprosthetic mitral valves, VIV-TMVR appears to confer a short-term advantage over re-SMVR in terms of morbidity, discharge home, and length of stay. It yielded equivalent outcomes for mortality and readmission. Longer-term studies are needed to assess further follow-up beyond 180 days.

Transcatheter mitral valve replacement versus redo surgery for mitral prosthesis failure: A systematic review and meta-analysis

Background

Transcatheter mitral valve replacement (TMVR) has emerged as an alternative to redo surgery. TMVR compared with redo surgical mitral valve replacement (SMVR) in patients with mitral prosthesis failure remains limited. In this study, we performed a meta-analysis to assess the outcomes of TMVR (including valve-in-valve and valve-in-ring) versus redo surgery for mitral prosthesis failure.

Methods

We comprehensively searched the PubMed, Embase, and Cochrane library databases according to predetermined inclusion and exclusion criteria, and then we extracted data. We compared the outcomes of TMVR and redo SMVR for mitral prosthesis failure in terms of the in-hospital mortality, stroke, renal dysfunction, vascular complication, pacemaker implantation, exploration for bleeding, paravalvular leak, mean mitral valve gradient, 30-day mortality, and 1-year mortality.

Results

Nine retrospective cohort studies and a total of 3,038 patients were included in this analysis. Compared with redo SMVR for mitral prosthesis failure, TMVR was associated with lower in-hospital mortality [odds ratios (OR): 0.44; 95% confidence interval (CI): 0.30-0.64; P < 0.001], stroke (OR: 0.44; 95% CI: 0.29-0.67; P = 0.0001), renal dysfunction (OR: 0.52; 95% CI: 0.37-0.75; P = 0.0003), vascular complication (OR: 0.58; 95% CI: 0.43-0.78; P = 0.004), pacemaker implantation (OR: 0.23; 95% CI: 0.15-0.36; P < 0.00001), and exploration for bleeding (OR: 0.24; 95% CI: 0.06-0.96; P = 0.04). Conversely, redo SMVR had lower paravalvular leak (OR: 22.12; 95% CI: 2.81-174.16; P = 0.003). There was no difference in mean mitral valve gradient (MD: 0.04; 95% CI: -0.47 to 0.55; P = 0.87), 30-day mortality (OR: 0.65; 95% CI: 0.36-1.17; P = 0.15), and 1-year mortality (OR: 0.96; 95% CI: 0.63-1.45; P = 0.84).

Conclusion

In patients with mitral prosthesis failure, TMVR is associated with lower in-hospital mortality and lower occurrence of postoperative complications, except for paravalvular leak. TMVR offers a viable alternative to the conventional redo surgery in selected patients.

Transcatheter mitral valve-in-valve: treatment of rheumatic heart disease in young patients

BACKGROUND

Rheumatic heart disease (RHD) in young people presents a complex management problem. In Australia a significant proportion of those affected are Aboriginal and Torres Strait Islanders. Transcatheter mitral valve-in-valve (TMViV) replacement has emerged as an alternative to redo surgery in high-risk patients with degenerated mitral bioprostheses. The aim of this study is to review outcomes of TMViV replacement in young patients with RHD.

METHODS

A single-centre, retrospective review of prospectively collected data on patients undergoing TMViV from December 2017 to June 2021. Primary outcome was major adverse cardiovascular events. Secondary outcome was post-operative trans-thoracic echocardiogram (TTE) results.

RESULTS

There were seven patients with a mean age of 33 years and predominantly female (n = 5). Pre-operative comorbidities included diabetes (29%), chronic obstructive pulmonary disease (43%), left ventricular dysfunction (43%) and current smoking status (80%). Post-operative median length of hospital stay was 4 days with no post-operative renal failure, stroke, return to theatre, valve embolization or in hospital mortality. Post-operative TTE showed either nil or trivial central mitral regurgitation, no paravalvular leak and a median gradient of 5 mmHg (IQR 4.5, 7) across the new bioprosthesis; sustained at median follow-up of 22 months.

CONCLUSION

Current literature of TMViV replacement is focused on an older population with concurrent comorbidities. This study provides a unique insight into TMViV replacement in a young cohort of patients with complex social and geographical factors which sometimes prohibits the use of a mechanical valve. The prevalence of RHD remains high for Aboriginal and Torres Strait Islanders, planning for future repeat valve operations should be considered from the outset. We consider TMViV as a part of a staged procedural journey for young patients with RHD.

Using tissue mitral valves in younger patients: A word of caution

BACKGROUND

The debate about the optimal mitral valve prosthesis continues. We aimed to compare the early and late outcomes, including stroke, bleeding, survival, and reoperation after isolated mitral valve replacement (MVR) using tissue versus mechanical valves.

METHODS

This retrospective cohort study included 291 patients who had isolated MVR from 2005 to 2015. Patients were grouped into the tissue valve group (n = 140) and the mechanical valve group (n = 151).

RESULTS

There were no differences in duration of mechanical ventilation, hospital stay, and hospital mortality between groups. Fifteen patients required cardiac rehospitalization, nine in the tissue valve group, and six in the mechanical valve group (p = .44). Stroke occurred in nine patients, five with tissue valves, and four with mechanical valves (p = .66). Bleeding occurred in 22 patients, seven patients with tissue valves, and 15 patients with mechanical valves (p = .09). Freedom from reoperation was 95%, 93%, 84%, 67% at 3, 5, 7, and 10 years for tissue valve and 97%, 96%, 96%, and 93% for mechanical valves, respectively (p˂ .001). The median follow-up was 84 months (Q1: Q3: 38-139). Survival at 3, 5, 7, and 10 years was 94%, 91%, 89%, 86% in tissue valves and 96%, 93%, 91%, 91% in mechanical valves, respectively (p = .49).

CONCLUSIONS

Tissue valve degeneration is still an issue even in the new generations of mitral tissue valves. The significant risk of reoperation in patients with mitral tissue valves should be considered when using those valves in younger patients. Mechanical valves remain a valid option for all age groups.

Transcatheter Mitral Valve Repair for Failed Surgical Mitral Valve Repair: A Systematic Review and Meta-Analysis

Objectives

To assess the outcomes of transcatheter mitral valve repair (TMVr) for failed previous surgical mitral valve repair (MVr).

Methods

We searched Pubmed, Embase, and Cochrane Library databases for studies that reported the outcomes of TMVr for failed initial surgical MVr. Data were extracted by 2 independent investigators and subjected to meta-analysis. The 95% confidence interval (CI) was calculated for preoperative demographics, peri-operative outcomes, and follow-up outcomes using binary and continuous data from single-arm studies.

Results

Eight single-arm studies were included, with a total of 212 patients, and mean follow-up ranged from 1.0 to 15.9 months. The pooled rate of residual procedural mitral regurgitation ≤ mild was 76% (95% CI: 67%~84%; I 2 = 0%; 7 studies, 199 patients). During follow-up, mitral regurgitation ≤ mild was found in 68% of patients (95% CI: 52%~82%; I 2 = 57%; 6 studies, 147 patients). Follow-up survival was 94% (95% CI: 88%~98%; I 2 = 0%; 7 studies, 196 patients). 83% patients (95% CI: 75%~89%; I 2 = 47%; 6 studies, 148 patients) were in NYHA class I or II.

Conclusions

TMVr for failed surgical MVr was safe and effective, which should be recommended in selected patients if technically feasible.

Long-Term Outcomes of the Mosaic Mitral Porcine Bioprosthesis in Japan - Results From the Japan Mosaic Valve Long-Term Multicenter Study

BACKGROUND

This study retrospectively evaluated the long-term patient outcomes and durability of the Mosaic mitral porcine bioprosthesis in the Japan Mosaic valve long-term multicenter study.

METHODS AND RESULTS

The medical records of 390 patients who underwent mitral valve replacement with the Mosaic bioprosthesis at 10 centers in Japan (1999-2014) were reviewed. Patient data were collected using the Research Electronic Data Capture software. Patient survival was determined using the Kaplan-Meier method. Freedom from structural valve deterioration (SVD) and valve-related reoperation and death were determined using actuarial methods. The median (interquartile range [IQR]) age of the cohort was 73 (69-77) years. The median (IQR) follow-up period was 4.83 (1.84-8.26) years. The longest follow-up period was 15.8 years. The 30-day mortality rate was 5.4%. The 12-year actuarial survival rate was 54.1±4.5%, and the freedom from valve-related death was 85.3±3.4%. The freedom from reoperation at 12 years was 74.3±5.7%. The freedom from SVD at 12 years was 81.4±6.6% for patients aged ≥65 years and 71.6±11.1% for those aged <65 years. The median (IQR) mean pressure gradient was 4.1 (3.0-6.0) and 5.6 (4.0-6.7) mmHg at 1 and 10 years, respectively. The median (IQR) effective orifice area was 1.7 (1.4-2.0) and 1.4 (1.2-1.6) cm2at 1 and 10 years, respectively.

CONCLUSIONS

The Mosaic porcine bioprosthesis offered satisfactory long-term outcomes for up to 12 years.

Outcomes of combined aortic and mitral valve replacement with reconstruction of the fibrous skeleton of the heart

OBJECTIVES

The objectives of this study were to examine operative and long-term results of combined aortic and mitral valve replacement when reconstruction of the fibrous skeleton of the heart is needed because of calcification, abscess, previous operations, or patient-prosthesis mismatch.

METHODS

From 1985 to 2020, 182 consecutive patients underwent combined aortic and mitral valve replacement with reconstruction of the intervalvular fibrous skeleton in all cases and also the posterior mitral annulus in 63 patients. Bovine pericardium or Dacron grafts were used for the reconstructions. Median follow-up was 7.5 (interquartile range, 2.1-12.6) years and 98% complete.

RESULTS

Patient mean age was 62 years; 69% had 1 or more previous valve operations, and 92% were functional class III or IV. The indications for reconstruction were extensive calcification of the fibrous skeleton in 34%, abscess in 13%, tissue damage secondary to previous operations in 39%, and patient-prosthesis mismatch of the mitral valve in 13%. Bovine pericardium was used in two-thirds of cases and Dacron grafts in one-third. Operative mortality was 13.2% and postoperative complications were common. Survival at 1, 10, and 20 years was 81.8%, 51.1%, and 23.7%, respectively. Fourteen patients required reoperation and 3 transcatheter interventions. The cumulative probability of reinterventions at 1, 10, and 20 years were 3.3%, 5.8%, and 9.1%, respectively. Most patients experienced symptomatic improvement postoperatively.

CONCLUSIONS

Reconstructions of the fibrous skeleton of the heart are associated with high operative mortality but the long-term results are satisfactory because most patients would not have survived without surgical intervention.

Access options for transcatheter mitral valve implantation in patients with prior surgical bioprosthesis

BACKGROUND

Transcatheter mitral valve-in-valve (TMVIV) procedure, either transapical (TA) or trans-septal (TS) has become a valuable alternative to conventional redo surgery in case of failing mitral bioprosthesis with good clinical outcomes. Here we present our fourteen-year institutional experience.

METHODS

All consecutive patients treated with TMVIV with either TA or TS access at our centre between July 2007 and July 2020 were included. Periprocedural and 30-day follow-up (FU) results are reported and TA and TS data are compared.

RESULTS

Eighty-two patients were included, of those 60 (73.2%) were TA while 22 (26.8%) were TS. Men represented 51.2% of the population with a mean age of 77.3±9.0 years. STS score and EuroSCORE II were 11.4%±6.2% and 11.5%±6.5% respectively. Baseline characteristics of TA and TS groups were comparable. TMVIV was performed at a median time of 9.3 years [interquartile range (IQR), 7.9-12.0 days] from the initial mitral valve surgery. Balloon expandable transcatheter heart valve (THV) prostheses (Edwards LifeSciences Corp., Irvine, CA, USA) were used exclusively. Technical success was 97.6% (96.7% and 100.0% for TA and TS respectively) with two (2.4%) periprocedural death, both in the TA group (P=0.533). We observed four (4.9%) left ventricular outflow tract (LVOT) obstructions with one being hemodynamically significant. Six (7.3%) major bleeding occurred in the TA group, not significantly different from TS group (P=0.279). The median length of stay was 6 days (IQR, 4-12 days, 1.5 vs. 7.0 days for TS and TA groups respectively, P=0.001). The overall 30-day mortality rate was 3.7%. We also observed three (3.7%) structural valve deteriorations and in one (1.2%) case the patient required redo mitral surgery at two months. Eighty-seven-point-eight percent of patients were I-II New York Heart Association (NYHA) class. At 30-day FU mean transmitral valve gradient was 7.3±2.7 mmHg and one patient (1.2%) had mitral regurgitation greater than mild. TA and TS groups were comparable.

CONCLUSIONS

Our 14-year single-center experience with TMVIV confirms procedural safety and is an effective alternative to redo surgery with comparable results with both TA and TS. With device, technical improvements and increasing operators' experience, TS is the preferred option for TMVIV. However, in some highly selected patient, TA may still play an important role.

Mitral surgical redo versus transapical transcatheter mitral valve implantation

Background

Transcatheter methods have been rapidly evolving to provide an alternative less invasive therapeutic option, mainly because redo patients often present with multiple comorbidities and high operative risk. We sought to evaluate and compare our experience with transapical transcatheter mitral valve replacement (TA-TMVR) to conventional redo mitral valve replacement in patients presenting with degenerated biological mitral valve prostheses or failed valve annuloplasty.

Methods and material

Between March 2012 and November 2020, 74 consecutive high-risk patients underwent surgical redo mitral valve replacement (n = 33) or TA-TMVR (n = 41) at our institution. All patients presented with a history of a surgical mitral valve procedure. All transcatheter procedures were performed using the SAPIEN XT/3™ prostheses. Data collection was prospectively according to MVARC criteria.

Results

The mean logistic EuroSCORE-II of the whole cohort was 19.9±16.7%, and the median STS-score was 11.1±12.5%. The mean age in the SMVR group was 63.7±12.8 years and in the TMVR group 73.6±9.7 years. Patients undergoing TA-TMVR presented with significantly higher risk scores. Echocardiography at follow up showed no obstruction of the left ventricular outflow tract, no paravalvular leakage and excellent transvalvular gradients in both groups (3.9±1.2 mmHg and 4.2±0.8 mmHg in the surgical and transcatheter arm respectively). There was no difference in postoperative major adverse events between the groups with no strokes in the whole cohort. Both methods showed similar survival rates at one year and a 30-day mortality of 15.2% and 9.8% in SAVR and TMVR group, respectively. Despite using contrast dye in the transcatheter group, the rate of postoperative acute kidney failure was similar between the groups.

Conclusion

Despite several contraindications for surgery, we showed the non-inferiority of TA-TMVR compared to conventional surgical redo procedures in high-risk patients. With its excellent hemodynamic and similar survival rate, TA-TMVR offers a feasible alternative to the conventional surgical redo procedure in selected patients.

Transcatheter Valve-in-Valve Procedures for Bioprosthetic Valve Dysfunction in Patients With Rheumatic vs. Non-Rheumatic Valvular Heart Disease

Background: Bioprosthetic heart valve has limited durability and lower long-term performance especially in rheumatic heart disease (RHD) patients that are often subject to multiple redo operations. Minimally invasive procedures, such as transcatheter valve-in-valve (ViV) implantation, may offer an attractive alternative, although data is lacking. The aim of this study was to evaluate the baseline characteristics and clinical outcomes in rheumatic vs. non-rheumatic patients undergoing ViV procedures for severe bioprosthetic valve dysfunction.

Methods: Single center, prospective study, including consecutive patients undergoing transcatheter ViV implantation in aortic, mitral and tricuspid position, from May 2015 to September 2020. RHD was defined according to clinical history, previous echocardiographic and surgical findings.

Results: Among 106 patients included, 69 had rheumatic etiology and 37 were non-rheumatic. Rheumatic patients had higher incidence of female sex (73.9 vs. 43.2%, respectively; p = 0.004), atrial fibrillation (82.6 vs. 45.9%, respectively; p < 0.001), and 2 or more prior surgeries (68.1 vs. 32.4%, respectively; p = 0.001). Although, device success was similar between groups (75.4 vs. 89.2% in rheumatic vs. non-rheumatic, respectively; p = 0.148), there was a trend toward higher 30-day mortality rates in the rheumatic patients (21.7 vs. 5.4%, respectively; p = 0.057). Still, at median follow-up of 20.7 [5.1–30.4] months, cumulative mortality was similar between both groups (p = 0.779).

Conclusion: Transcatheter ViV implantation is an acceptable alternative to redo operations in the treatment of patients with RHD and severe bioprosthetic valve dysfunction. Despite similar device success rates, rheumatic patients present higher 30-day mortality rates with good mid-term clinical outcomes. Future studies with a larger number of patients and follow-up are still warranted, to firmly conclude on the role transcatheter ViV procedures in the RHD population.

Mitral Valve Annuloplasty Failure and Percutaneous Treatment Options

PURPOSE OF REVIEW

Mitral valve repair is a common surgical procedure for both primary and secondary mitral regurgitation. With operations performed earlier in disease progression and increased patient longevity, the need for a repeat intervention is not infrequent. With the associated risks of reoperation and patient comorbidities, percutaneous techniques for acute or delayed failure after ring annuloplasty are emerging.

RECENT FINDINGS

Current commercially available devices, used in "off-label" ways, such as the MitraClip, may be effective in repairing recurrent mitral regurgitation after annuloplasty. Similarly, a valve-in-ring transcatheter mitral valve replacement can be considered in patients at high risk for surgical reoperation. These procedures are not without risk, for example, resultant mitral stenosis in the setting of edge-to-edge repair or left ventricular outflow tract (LVOT) obstruction with valve-in-ring transcatheter mitral valve replacement. Newer devices are emerging to permit more options for this subset of patients, which include transcatheter valves that are specifically designed for the mitral position. Undoubtedly, surgical reoperation has increased risk as compared to primary operation. Though percutaneous options are evolving, use in this patient population is currently limited to "off-label" use and is also associated with procedural complexities and risk. It is prudent for cardiologists, surgeons, and anesthesiologists to weigh risks, benefits, and limitations when considering patients for surgical reoperation, percutaneous repair, or transcatheter replacement after failed mitral annuloplasty.

Surgical redo mitral valve replacement in high-risk patients: The real-world experience

INTRODUCTION

Redo surgical mitral valve replacement (SMVR) remains the gold standard treatment in patients with a history of mitral valve surgery presenting with recurrent mitral valve pathologies. Whilst this procedure is demanding, it is an inevitable intervention for some indications, such as infective endocarditis, thrombosis, or multivalve procedures. In this study, we aim to evaluate our institutional experience with SMVR on a real-life cohort, identifying the factors that contribute to poor surgical outcomes whilst avoiding selection bias.

METHODS

Between March 2012 and November 2020, 58 consecutive high-risk patients underwent a redo SMVR at our institution. The primary endpoints of this study were 30-day and 1-year mortality. The secondary endpoint was the development of any postoperative adverse events. We analyzed and compared the survival in patients undergoing an isolated SMVR and in those that required at least one concomitant procedure.

RESULTS

The overall operative, 30-day, and 1-year mortality were 3.4%, 22.4%, and 25.9%, respectively. The mortality in patients undergoing isolated SMVR was significantly lower than in patients requiring concomitant procedures. The multivariable regression model showed that NYHA Class IV, infective endocarditis, and postoperative dialysis were significantly associated with 30-day mortality. Society of Thoracic Surgeons Score, infective endocarditis, concomitant procedures, and mechanical valve implantation appeared to predict long-term mortality.

CONCLUSION

This study illustrates that SMVR after prior mitral valve surgery presents a demanding procedure with high operative risk, significant mortality, and morbidity. Whilst this procedure is inevitable for some indications, a careful patient selection and risk stratification provides acceptable surgical results in this cohort.

Reoperative Mitral Surgery Versus Transcatheter Mitral Valve Replacement: A Systematic Review

Bioprosthetic mitral structural valve degeneration and failed mitral valve repair (MVr) have traditionally been treated with reoperative mitral valve surgery. Transcatheter mitral valve-in-valve (MVIV) and valve-in-ring (MVIR) replacement are now feasible, but data comparing these approaches are lacking. We sought to compare the outcomes of (1) reoperative mitral valve replacement (redo-MVR) and MVIV for structural valve degeneration, and (2) reoperative mitral valve repair (redo-MVr) or MVR and MVIR for failed MVr. A literature search of PubMed, Embase, and the Cochrane Library was conducted up to July 31, 2020. Thirty-two studies involving 25 832 patients were included. Redo-MVR was required in ≈35% of patients after index surgery at 10 years, with 5% to 15% 30-day mortality. MVIV resulted in >95% procedural success with 30-day and 1-year mortality of 0% to 8% and 11% to 16%, respectively. Recognized complications included left ventricular outflow tract obstruction (0%-6%), valve migration (0%-9%), and residual regurgitation (0%-6%). Comparisons of redo-MVR and MVIV showed no statistically significant differences in mortality (11.3% versus 11.9% at 1 year, P=0.92), albeit higher rates of major bleeding and arrhythmias with redo-MVR. MVIR resulted in 0% to 34% mortality at 1 year, whereas both redo-MVr and MVR for failed repairs were performed with minimal mortality and durable long-term results. MVIV is therefore a viable alternative to redo-MVR for structural valve degeneration, whereas redo-MVr or redo-MVR is preferred for failed MVr given the suboptimal results with MVIR. However, not all patients will be candidates for MVIV/MVIR because anatomical restrictions may preclude transcatheter options from adequately addressing the underlying pathology.