Mitral valve replacements in redo patients with previous mitral valve procedures: mid-term results and risk factors for survival

Minimally Invasive Procedure versus Conventional Redo Sternotomy for Mitral Valve Surgery in Patients with Previous Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

The heightened morbidity and mortality associated with repeat cardiac surgery are well documented. Redo median sternotomy (MS) and minimally invasive valve surgery are options for patients with prior cardiac surgery who require mitral valve surgery (MVS). We conducted a systematic review and meta-analysis comparing the outcomes of redo MS and minimally invasive MVS (MIMVS) in this population.

Methods

We searched PubMed, EMBASE, and Scopus for studies comparing outcomes of redo MS and MIMVS for MVS. To calculate risk ratios (RRs) for binary outcomes and weighted mean differences (MDs) for continuous data, we employed a random-effects model.

Results

We included 12 retrospective observational studies, comprising 4157 participants (675 for MIMVS; 3482 for redo MS). Reductions in mortality (RR, 0.54; 95% confidence interval [CI], 0.37-0.80), length of hospital stay (MD, -4.23; 95% CI, -5.77 to -2.68), length of intensive care unit (ICU) stay (MD, -2.02; 95% CI, -3.17 to -0.88), and new-onset acute kidney injury (AKI) risk (odds ratio, 0.34; 95% CI, 0.19 to 0.61) were statistically significant and favored MIMVS (p<0.05). No significant differences were observed in aortic cross-clamp time, cardiopulmonary bypass time, or risk of perioperative stroke, new-onset atrial fibrillation, surgical site infection, or reoperation for bleeding (p>0.05).

Conclusion

The current literature, which primarily consists of retrospective comparisons, underscores certain benefits of MIMVS over redo MS. These include decreased mortality, shorter hospital and ICU stays, and reduced AKI risk. Given the lack of high-quality evidence, prospective randomized control trials with adequate power are necessary to investigate long-term outcomes.

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.

Effects of Transapical Transcatheter Mitral Valve Implantation

Purpose: In this study, transapical transcatheter mitral valve-in-valve implantation (TAMVI) was compared with surgical redo mitral valve replacement (SRMVR) in terms of clinical outcomes.

Methods: We retrospectively identified patients with degenerated mitral bioprosthesis or failed annuloplasty rings who underwent redo SRMVR or TAMVI at our medical center. Clinical outcomes were based on echocardiography results.

Results: We retrospectively identified patients with symptomatic mitral bioprosthetic valve dysfunction (n = 58) and failed annuloplasty rings (n = 14) who underwent redo SRMVR (n = 36) or TAMVI (n = 36). The Society of Thoracic Surgeons Predicted Risk of Mortality scores were higher in the TAMVI group (median: 9.52) than in the SRMVR group (median: 5.59) (p-value = 0.02). TAMVI patients were more severe in New York Heart Association (p-value = 0.04). The total procedure time (skin to skin) and length of stay after procedures were significantly shorter in the TAMVI group, and no significant difference in mortality was noted after adjustment for confounding factors (p-value = 0.11). The overall mean mitral valve pressure gradient was lower in the TAMVI group than in the SRMVR group at 24 months (p < 0.01). Both groups presented a decrease in the severity of mitral and tricuspid regurgitation at 3–24 months.

Conclusions: In conclusion, the statistical analysis is still not robust enough to make a claim that TAMVI is an appropriate alternative. The outcome of the patient appears only to be related to the patient's pre-operative STS score. Additional multi-center, longitudinal studies are warranted to adequately assess the effect of TAMVI.

Contemporary Reoperative Mitral Valve Surgery: Technical Considerations and Clinical Outcomes

As patients with cardiac disease live longer, reoperative mitral valve surgery has become more common. Although these operations are technically challenging and of high risk, outcomes continue to improve. Minimally invasive techniques, better cardioprotective strategies, and advanced perioperative care have contributed to this. In this review, we discuss surgical approaches, intraoperative strategies, novel catheter-directed devices, and clinical outcomes of contemporary reoperative mitral valve surgery.

Contemporary outcomes in reoperative mitral valve surgery

Objective

Data suggest that redo mitral valve surgery is being performed in increasing numbers, possibly with superior results according to single-centre studies. The purpose of this study is to describe outcomes of redo mitral valve surgery and identify risk-adjusted predictors of poor outcomes.

Methods

All (11 973) open mitral valve cases were evaluated (2002–2016) from a regional Society of Thoracic Surgery (STS) database. Patients were stratified by primary versus redo mitral valve surgery. Mixed effects logistic regression models including hospital as a random effect were used to identify risk factors for patients undergoing redo mitral valve surgery.

Results

Of all mitral valve cases, 1096 (9.7%) had a previous mitral operation. Redo patients had higher rates of valve replacement and preoperative comorbidities resulting in more complications, operative mortalities (11.1%vs6.5%, p<0.0001) and higher resource utilisation. Several factors independently increased risk for composite STS major morbidity and 30-day mortality, including cardiogenic shock (OR 10.3, p=0.0001), severe tricuspid insufficiency (OR 2.3, p=0.001), urgent/emergent status (OR 1.8, p=0.001) and concurrent coronary artery bypass grafting (OR 2.4, p=0.002). The volume of redo mitral valve surgery increased 10% per year and the observed-to-expected ratios (O/E) for operative mortality in redo mitral surgery improved from 1.44 early in the study period to 0.72 in the most recent era.

Conclusions

Redo mitral valve surgery accounts for approximately 10% of mitral valve operations and is associated with increased risk and resource utilisation. However, as the volume of redo mitral surgery increases, outcomes have dramatically improved and are now better than predicted.

Haemodynamic improvement of older, previously replaced mechanical mitral valves by removal of the subvalvular pannus in redo cardiac surgery

Patients requiring redo cardiac surgery for diseased heart valves other than mitral valves may show increased pressure gradients and reduced valve areas of previously placed mechanical mitral valves due to subvalvular pannus formation. We treated four women who had mechanical mitral valves inserted greater than or equal to 20 years earlier and who presented with circular pannus that protruded into the lower margin of the valve ring but did not impede leaflet motion. Pannus removal improved the haemodynamic function of the mitral valve.

Gender-Based Long-Term Surgical Outcome in Patients with Active Infective Aortic Valve Endocarditis

BACKGROUND The aim of this observational, single-center study was to evaluate the impact of gender on surgical outcome in patients with active infective endocarditis (AIE) of the aortic valve. MATERIAL AND METHODS Between October 1994 and January 2011, 755 patients (558 men and 297 women) underwent surgery for AIE at the Leipzig Heart Center, Germany, according to the modified Duke criteria. Data were collected before surgery and as the study was ongoing. Gender influence on survival was evaluated (Kaplan-Meier curves). Cox proportional models were used to evaluate gender differences in relation to early mortality (within 30 days) and late mortality (up to 10 years). RESULTS The early mortality rate was 15.0% among men and 23.0% among women, which was statistically significant different (p=0.01). In male patients, variables associated with overall mortality were age (HR 1.63, 95% CI 1.43-1.86; p<0.001), insulin-dependent diabetes mellitus (HR 2.02, 95% CI 1.48-2.75; p<0.001), preoperative low ejection fraction (OR 0.99, 95% CI 0.98-0.99; p=0.002), previous cardiac surgery (OR 1.62, 95% CI 1.22-2.13; p=0.001), preoperative ventilation (OR 1.77, 95% CI 1.14-2.75; p=0.012), preoperative dialysis (OR 1.89, 95% CI 1.20-2.98; p=0.006), NYHA Class IV (OR 1.56, 95% CI 1.12-2.15; p=0.008), and involvement of multiple valves (OR 1.65, 95% CI 1.24-2.19; p=0.001) had a statistically significant influence on the late mortality. Focus identification (OR 1.75, 95% CI 1.08-2.77; p=0.023), involvement of multiple valves (OR 1.52, 95% CI 1.02-2.26; p=0.040), preoperative dialysis (OR 3.65, 95% CI 1.96-6.77; p<0.001), and age (OR 1.53, 95% CI 1.28-1.82; p<0.004) were predictive risk factors for late mortality in women with AIE (OR 3.6, 95% CI 1.5-8.4; p<0.004). CONCLUSIONS This study demonstrated distinct gender-based differences in risk of mortality in patients with AIE (who were undergoing surgical treatment) with different early and long-term outcomes.

Outcome after redo-mitral valve replacement in adult patients: a 10-year single-centre experience

The aim of this study was to investigate the overall outcome of adult patients undergoing redo-mitral valve replacement (redo-MVR) at our institution. Forty-nine patients (24 males) underwent redo-MVR with either bioprosthetic (n = 24) or mechanical valves (n = 25) between January 2000 and 2010. Median age of patients was 63 years (range 21-80 years), and the mean additive EuroSCORE was 12 ± 4. Median time to re-operation was 8.2 ± 6.6 years for first time redo-MVR and 6.4 ± 5.6 years for second-time redo-MVR. Indications included prosthetic endocarditis (n = 22), para-prosthetic leak (n = 12), structural valve degeneration (n = 8), prosthetic valve thrombosis (n = 6) and malignancy (n = 1). The mean follow-up was 47.5 ± 37.0 months (range 0.1-112.3 months). In-hospital mortality was 12% (n = 6). Mean hospital stay was 17 ± 11 days (range 8-50 days). Actuarial survival at 1 and 5 years was 81 ± 5% and 72 ± 6%, respectively. Three patients required re-intervention: two for prosthetic valve endocarditis and one for para-prosthetic leak. Multivariate analysis showed that overall survival was associated with the LVEF < 50% (P < 0.001), concomitant AVR (P < 0.001) and urgent surgery (P = 0.03).