Surgical revascularization is associated with maximal survival in patients with ischemic mitral regurgitation: a 20-year experience

Efficacy of mitral valve repair in combination with coronary revascularization for moderate ischaemic mitral regurgitation: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of mitral valve repair (MVR) in combination with coronary artery bypass grafting (CABG) for moderate ischaemic mitral regurgitation (IMR) remains unclear. To evaluate whether MVR + CABG is superior to CABG alone, the authors conducted a systematic review and meta-analysis of existing randomized controlled trials (RCTs).

METHODS

The authors searched PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for eligible RCTs from the date of their inception to October 2023. The primary outcomes were operative (in-hospital or within 30 days) and long-term (≥ 1 year) mortality. The secondary outcomes were postoperative stroke, worsening renal function (WRF), and reoperation for bleeding or tamponade. The authors performed random-effects meta-analyses and reported the results as risk ratios (RRs) with 95% CIs.

RESULTS

Six RCTs were eligible for inclusion. Compared with CABG alone, MVR + CABG did not increase the risk of operative mortality (RR, 1.244; 95% CI, 0.514-3.014); however, it was also not associated with a lower risk of long-term mortality (RR, 0.676; 95% CI, 0.417-1.097). Meanwhile, there was no difference between the two groups in terms of postoperative stroke (RR, 2.425; 95% CI, 0.743-7.915), WRF (RR, 1.257; 95% CI, 0.533-2.964), and reoperation for bleeding or tamponade (RR, 1.667; 95% CI, 0.527-5.270).

CONCLUSIONS

The findings of this meta-analysis suggest that MVR + CABG fails to improve the clinical outcomes of patients with moderate IMR compared to CABG alone.

A treatment algorithm for ischemic cardiomyopathy

Treatment of ischemic cardiomyopathy has been the focus of increased attention by cardiologists due to recent evidence of an important outcome study comparing percutaneous coronary intervention (PCI) plus optimal medical treatment vs optimal medical treatment alone, concluding for the futility of myocardial revascularization by PCI. A relatively older trial of coronary artery bypass grafting (CABG) in the same condition, on the other hand, had concluded for some prognostic improvement at a long-term follow-up. This short manuscript addresses how to triage such patients, frequently encountered in medical practice and considering clinical presentation, imaging results, and surgical risk, to provide practical guidance to treatment.

Restrictive annuloplasty on remodeling and survival in patients with end-stage ischemic cardiomyopathy

OBJECTIVES

To elucidate the influence of concomitant restrictive mitral annuloplasty (RMA) on postoperative left ventricular (LV) reverse remodeling and survival in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting (CABG).

METHODS

This study comprised 157 patients with ischemic cardiomyopathy (LV ejection fraction ≤40%) who underwent CABG and completed echocardiographic examination at 1 year after surgery, with 84 (54%) undergoing concomitant RMA for clinically relevant ischemic mitral regurgitation. The primary end point was postoperative reduction in LV end-systolic volume index (LVESVI). The secondary end point was overall survival. Median follow-up was 5.1 years.

RESULTS

At baseline, patients who underwent CABG with RMA had a larger LVESVI (83 ± 23 vs 75 ± 24 mm; P = .046). One-year postoperatively, CABG with RMA reduced the LVESVI more than did CABG alone (37% vs 21% from baseline; P < .001), yielding nearly identical postoperative LVESVI (53 ± 27 vs 61 ± 26 mm; P = .065). In multivariable logistic regression analysis, concomitant RMA was associated with significant LV reverse remodeling (odds ratio, 2.79; 95% CI, 1.34-5.78; P = .006). The prevalence in moderate or severe mitral regurgitation was not different between the groups (7% vs 10%; P = .58). Survival rates were similar between the groups (5 years, 78% vs 83%; P = .35).

CONCLUSIONS

In patients with ischemic cardiomyopathy undergoing CABG, concomitant RMA was associated with significant reduction in LVESVI. The influence of LV reverse remodeling on survival remains undetermined.

Comparison of Coronary Artery Bypass Grafting Combined With Mitral Valve Repair Versus Coronary Artery Bypass Grafting Alone in Patients With Moderate Ischemic Mitral Regurgitation: A Meta-Analysis

The aim of this meta-analysis was to compare clinical outcomes between those who underwent coronary artery bypass grafting (CABG) alone and CABG with mitral valve repair (MVR) in patients with moderate ischemic mitral regurgitation. The present study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two authors performed a comprehensive search of international databases, including PubMed, EMBASE, and the Cochrane Library, for relevant studies published from inception to March 1, 2023. The search was performed again before the submission of the manuscript on March 20, 2023. Primary outcomes assessed in the present meta-analysis included early mortality and long-term mortality. Secondary outcomes assessed in the present meta-analysis included change in New York Heart Association (NYHA) score from baseline, change in ejection fraction (EF) from baseline (%), and major cardiovascular events (MACE). A total of 13 studies were included in the present meta-analysis. Out of 13 included studies, four were randomized control trials (RCTs) and nine were retrospective cohort studies. The pooled analysis showed that early mortality was significantly lower in patients in the CABG group compared to the CABG+MVR group (risk ratio [RR]: 0.47, 95% confidence interval [CI]: 0.31, 0.70). Long-term mortality was also lower in patients who underwent CABG compared to patients in the CABG+MVR group. However, the difference was statistically insignificant (RR: 0.88, 95% CI: 0.77, 1.02). No significant differences were reported in the EF score between patients who underwent CABG and patients who underwent CABG plus MVR (mean difference [MD]: 0.40, 95% CI: -1.90, 2.69). NYHA score was significantly lower in patients in the CABG+repair group compared to the CABG alone group (MD: 0.39, 95% CI: 0.06, 0.72). In conclusion, our meta-analysis suggests that concomitant MVR during CABG may not improve clinical outcomes in patients with moderate ischemic mitral regurgitation. Further clinical trials are needed to investigate this intervention in more detail.

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Impact of Mitral Regurgitation Recurrence on Mitral Valve Repair for Secondary Ischemic Mitral Regurgitation

OBJECTIVES

The current guidelines still do not include specific recommendations on the use of subvalvular repair (SV-r) for treatment of ischemic mitral regurgitation (IMR). Therefore, the objective of our study was to evaluate the clinical impact of mitral regurgitation (MR) recurrence and ventricular remodeling on long-term outcomes after SV-r combined with restrictive annuloplasty (RA-r).

METHODS

We performed a subanalysis of the papillary muscle approximation trial, studying 96 patients with severe IMR and coronary artery disease undergoing restrictive annuloplasty alongside subvalvular repair (SV-r + RA-r group) or restrictive annuloplasty alone (RA-r group). We analyzed treatment failure differences, the influence of residual MR, left ventricular remodeling, and clinical outcomes. The primary endpoint was treatment failure (composite of death; reoperation; or recurrence of moderate, moderate-to-severe, or severe MR) within 5 years of follow-up after the procedure.

RESULTS

A total of 45 patients showed failure of the treatment within 5 years, of which 16 patients underwent SV-r + RA-r (35.6%) and 29 underwent RA-r (64.4%, p = 0.006). Patients with significant residual MR presented with a higher rate of all-cause mortality at 5 years compared with trivial MR (HR 9.09, 95% CI 2.08-33.33, p = 0.003). MR progression occurred earlier in the RA-r group, as 20 patients in the RA-r group vs. 6 in SV-r + RA-r group had a significant MR 2 years after surgery (p = 0.002).

CONCLUSIONS

RA-r remains a surgical mitral repair technique with an increased risk of failure and mortality at 5 years compared with SV-r. The rates of recurrent MR are higher, and recurrence occurs earlier, with RA-r alone compared to SV-r. The addition of the subvalvular repair increases the durability of the repair, thus extending all of the benefits of preventing MR recurrence.

Prosthetic Mitral Valve Thrombosis: A Complication Following Mitral Valve Surgery and Coronary Artery Bypass Graft Surgery

Mitral valve regurgitation is a common valvular defect that can lead to severe complications, requiring surgical intervention, often in the form of either mitral valve repair or replacement. This case report follows a 63-year-old male with multivessel coronary artery disease, who initially presented to the emergency department (ED) with a non-ST elevation myocardial infarction (NSTEMI) secondary to multivessel coronary artery disease with severe mitral regurgitation, and subsequently underwent coronary artery bypass grafting (CABG) with repair of the mitral valve. He was readmitted a month later with endocarditis of the mitral valve and underwent a reoperation with a bioprosthetic mitral valve replacement and massive reconstruction of the right ventricle, after which he failed to recover postoperatively. A repeat transesophageal echocardiogram (TEE) during his final chest washout procedure revealed echodensities suspicious for thrombi and, despite the team’s best efforts, the patient expired. This report demonstrates that even with appropriate medical decision-making, poor outcomes still result, especially in patients with comorbidities including multivessel disease, respiratory illness, and endocarditis. This study suggests that continuing to characterize repairs or replacements of the mitral valve is essential. Additionally, aggressive and newly emerging procedures, such as percutaneous approaches to mitral valve repair or replacement, may be considered for use to mitigate negative outcomes, especially with an aging population.

The association between myocardial scar and the response of moderate ischemic mitral regurgitation to isolated coronary artery bypass grafting

Background

The factors that associated with the response of moderate ischemic mitral regurgitation (IMR) to isolated coronary artery bypass grafting (CABG) remain unclear. This study aims to evaluate whether left ventricular (LV) myocardial scar assessed by cardiovascular magnetic resonance (CMR) is associated with the outcome of moderate IMR after isolated CABG.

Methods

Forty-six patients with coronary artery disease (CAD) and moderate IMR who underwent isolated CABG between January 2014 and February 2019 in Anzhen Hospital Affiliated to Capital Medical University were enrolled in this case-control study. All patients underwent CMR and echocardiography before surgery. Patients were classified into two groups according to the severity of IMR 1 year after CABG: an improved group (no or mild IMR) and an unimproved group (moderate or severe IMR). Univariate and multivariate logistic regression analyses were used to assess the association between individual variables and unimproved IMR at 1-year post-CABG.

Results

Compared to patients in the improved group, the patients in the unimproved group had a significantly greater amount of LV myocardial scar (18.0%±9.5% vs. 30.8%±11.2%, P<0.001). In the multiple logistic regression model, after adjustment for age, sex, and body mass index, only LV myocardial scar (OR: 0.89, 95% CI: 0.83–0.96, P=0.001) was independently associated with unimproved IMR after isolated CABG. Furthermore, there was no difference in the 3-year overall survival rates between the two groups (92.3% vs. 90.3%, P=0.46). In addition, patients in the unimproved group had a higher New York Heart Association (NYHA) classification (P=0.01) and more major adverse cardiac events such as MI, angina pectoris, and readmission for heart failure (P=0.03).

Conclusions

A greater amount of preoperative LV myocardial scar was associated with unimproved moderate IMR after isolated CABG. Measuring preoperative LV myocardial scar is helpful to predict post-operative outcome and determine optimal surgery in patients with moderate IMR.

Multiple percutaneous coronary interventions worsen outcomes for subsequent surgical correction of chronic ischemic mitral regurgitation

Objective

We investigated whether or not a history of multiple percutaneous coronary interventions (PCIs) is associated with clinical outcomes after surgery for ischemic mitral regurgitation.

Methods

A total of 309 patients with chronic ischemic mitral regurgitation and left ventricular ejection fraction ≤40% who underwent restrictive mitral annuloplasty were classified as follows: patients with no or 1 previous PCI (nonmultiple PCI group [n = 211]) and patients with 2 or more previous PCIs (multiple PCIs group [n = 98]). Mean follow-up duration was 53 ± 40 months.

Results

Before surgery, there were no intergroup differences in patient demographic characteristics except for lower estimated glomerular filtration rate in patients with multiple PCIs. These patients underwent concomitant coronary artery bypass grafting less frequently with a lower number of distal anastomoses (P < .05 for both). The 30-day mortality was 3.3% and 2.0% in the nonmultiple and multiple PCIs group, respectively (P = .72). During follow-up, there were 157 deaths. Patients with multiple PCIs showed lower 5-year survival rate (44% vs 64%; P = .002). After adjustments with inverse-probability-of-treatment weighting, multiple PCIs history was an independent risk factor for mortality (adjusted hazard ratio, 1.4; 95% confidential interval, 1.1-1.7; P = .002). Patients with multiple PCIs showed less improvement in left ventricular ejection fraction (interaction effect P < .001).

Conclusions

In patients with ischemic mitral regurgitation, a history of previous multiple PCIs was associated with increased risk of long-term postoperative mortality, with less improvement in left ventricular ejection fraction.

Effect of Neprilysin Inhibition for Ischemic Mitral Regurgitation after Myocardial Injury

Angiotensin receptor neprilysin inhibitor (ARNI) treatment reduces functional mitral regurgitation (MR) to a greater extent than angiotensin receptor blocker (ARB) treatment alone, but the mechanism is unclear. We evaluated the mechanisms of how ARNI has an effect on functional MR. After inducing functional MR by left circumflex coronary artery occlusion, male Sprague Dawley rats (n = 31) were randomly assigned to receive the ARNI LCZ696, the ARB valsartan, or corn oil only (MR control). Excised mitral leaflets and left ventricle (LV) were analyzed, and valvular endothelial cells were evaluated focusing on molecular changes. LCZ696 significantly attenuated LV dilatation after 6 weeks when compared with the control group (LV end-diastolic volume, 461.3 ± 13.8 µL versus 525.1 ± 23.6 µL; p < 0.05), while valsartan did not (471.2 ± 8.9 µL; p > 0.05 to control). Histopathological analysis of mitral leaflets showed that LCZ696 strongly reduced fibrotic thickness compared to the control group (28.2 ± 2.7 µm vs. 48.8 ± 7.5 µm; p < 0.05). Transforming growth factor-β and downstream phosphorylated extracellular-signal regulated kinase were also significantly lower in the LCZ696 group. Consequently, excessive endothelial-to-mesenchymal transition (EndoMT) was mitigated in the LCZ696 group compared to the control group and leaflet area was higher (11%) in the LCZ696 group than in the valsartan group. Finally, the MR extent was significantly lower in the LCZ696 group and functional improvement was observed. In conclusion, neprilysin inhibitor has positive effects on LV reverse remodeling and also attenuates fibrosis in MV leaflets and restores adaptive growth by directly modulating EndoMT.

Left ventricle-mitral valve ring size mismatch following ring annuloplasty for nonischemic dilated cardiomyopathy

BACKGROUND

In patients with ischemic mitral regurgitation (MR) undergoing restrictive mitral annuloplasty (RMA), the ratio of left ventricular (LV) end-systolic dimension (LVESD) to mitral valve (MV) ring size (ie, LV-MV ring mismatch) is associated with postoperative recurrent MR. However, the impact of LV-MV ring mismatch on postoperative recurrent MR, LV function recovery, and long-term survival in patients with nonischemic dilated cardiomyopathy (DCM) remains unknown.

METHODS

Sixty-six patients with nonischemic DCM (mean LVESD, 62 mm) underwent RMA (mean ring size, 26 mm) between 2003 and 2014. Recurrent MR was defined as MR grade ≥2+ at a 6-month echocardiographic evaluation.

RESULTS

At the 6-month follow-up, 23 patients (35%) had developed recurrent MR. In univariable logistic regression analysis, larger LVESD (P = .012) and LVESD/ring size ratio (P = .008) were associated with recurrent MR. In multivariable models adjusted for age, sex, baseline LV ejection fraction, and severe MR, only LVESD/ring size ratio (odds ratio, 4.65; 95% confidence interval, 1.04-25.0; P = .048) remained significantly associated with MR recurrence. Receiver operating characteristic curve analysis demonstrated an optimal cutoff value for the LVESD/ring size ratio of 2.42. Patients with an LVESD/ring size ratio >2.42 (n = 30; mismatch) had a lower 5-year cumulative survival rate compared with those with an LVESD/ring size ratio ≤2.42 (n = 36; nonmismatch) (52% vs 71%; P = .045). Postoperatively, LV dimensions were significantly reduced in both groups; however, improvements in LVEF were only modest in the mismatched group (P = .091).

CONCLUSIONS

LV-MV ring size mismatch was associated with an increased risk of recurrent MR in our series. This finding may aid the formulation of surgical strategies for patients with nonischemic DCM.

Secondary valve regurgitation in patients with heart failure with preserved ejection fraction, heart failure with mid-range ejection fraction, and heart failure with reduced ejection fraction

Secondary mitral regurgitation and secondary tricuspid regurgitation due to heart failure (HF) remain challenging in almost every aspect: increasing prevalence, poor prognosis, notoriously elusive in diagnosis, and complexity of therapeutic management. Recently, defined HF subgroups according to three ejection fraction (EF) ranges (reduced, mid-range, and preserved) have stimulated a structured understanding of the HF syndrome but the role of secondary valve regurgitation (SVR) across the spectrum of EF remains undefined. This review expands this structured understanding by consolidating the underlying phenotype of myocardial impairment with each type of SVR. Specifically, the current understanding, epidemiological considerations, impact, public health burden, mechanisms, and treatment options of SVR are discussed separately for each lesion across the HF spectrum. Furthermore, this review identifies important gaps in knowledge, future directions for research, and provides potential solutions for diagnosis and treatment. Mastering the challenge of SVR requires a multidisciplinary collaborative effort, both, in clinical practice and scientific approach to optimize patient outcomes.

10-Year Results of Mitral Repair and Coronary Bypass for Ischemic Regurgitation: A Randomized Trial

BACKGROUND

The decision to treat moderate ischemic mitral regurgitation (IMR) at the time of coronary artery bypass surgery (CABG) remains controversial. We previously conducted a prospective randomized trial that showed a benefit of adding restricted annuloplasty to bypass surgery (CABG-Ring group) in terms of IMR grade, New York Heart Association classification, and left ventricle reverse remodeling. Here, we present the long-term (>10 years) follow-up data from this randomized trial.

METHODS

The original trial arms accounted for 54 patients in the CABG-alone and 48 in the CABG-Ring group; patients were re-contacted for follow-up to obtain relevant clinical and echocardiographic information.

RESULTS

The mean follow-up was 160.4 ± 45.5 months. Survival probabilities in the CABG-alone and CABG-Ring groups were 96% vs 93% at 3 years, 85% vs 89% at 6 years, 79% vs 85% at 9 years, 77% vs 83% at 12 years, and 72% vs 80% at 15 years, respectively (P = .18) Freedom from at least moderate IMR or reintervention at last follow-up was also higher in the CABG-Ring group (P < .001). Compared with the CABG-alone group, the CABG-Ring group had a higher degree of left ventricular reverse remodeling (54.7 ± 6.9 mm vs 51.6 ± 6 mm, respectively; P = .03), lower New York Heart Association class (P < .001), and a lower rate of rehospitalization (P = .002).

CONCLUSIONS

Long-term follow-up data from our randomized trial further support the utility of performing restricted annuloplasty at the time of CABG to prevent further progression of IMR, mitral reintervention, and left ventricle remodeling. Untreated IMR was associated with significantly higher New York Heart Association class and rehospitalization.

The role of transcatheter mitral valve leaflet approximation for the treatment of secondary mitral regurgitation: current status and future prospects

Introduction: Secondary mitral regurgitation (SMR) is one of the most common valvulopathies and is associated with poor prognosis. Over the past years, medical management and mitral valve repair options have rapidly evolved offering new opportunities for a wide range of patients.Areas covered: We provide an up-to-date review of the value of medical and transcatheter mitral valve leaflet approximation for SMR integrating the results of most recent trials and putting their findings into clinical perspective.Expert opinion: Treatment of SMR requires a multidisciplinary approach with a long-term perspective. After optimization of medical treatment, transcatheter mitral valve repair should be considered in patients with persisting symptomatic severe SMR to improve symptoms and prognosis.

The management of secondary mitral regurgitation in patients with heart failure: a joint position statement from the Heart Failure Association (HFA), European Association of Cardiovascular Imaging (EACVI), European Heart Rhythm Association (EHRA), and European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the ESC

Secondary (or functional) mitral regurgitation (SMR) occurs frequently in chronic heart failure (HF) with reduced left ventricular (LV) ejection fraction, resulting from LV remodelling that prevents coaptation of the valve leaflets. Secondary mitral regurgitation contributes to progression of the symptoms and signs of HF and confers worse prognosis. The management of HF patients with SMR is complex and requires timely referral to a multidisciplinary Heart Team. Optimization of pharmacological and device therapy according to guideline recommendations is crucial. Further management requires careful clinical and imaging assessment, addressing the anatomical and functional features of the mitral valve and left ventricle, overall HF status, and relevant comorbidities. Evidence concerning surgical correction of SMR is sparse and it is doubtful whether this approach improves prognosis. Transcatheter repair has emerged as a promising alternative, but the conflicting results of current randomized trials require careful interpretation. This collaborative position statement, developed by four key associations of the European Society of Cardiology-the Heart Failure Association (HFA), European Association of Percutaneous Cardiovascular Interventions (EAPCI), European Association of Cardiovascular Imaging (EACVI), and European Heart Rhythm Association (EHRA)-presents an updated practical approach to the evaluation and management of patients with HF and SMR based upon a Heart Team approach.

The unfinished saga of invasive procedures for secondary mitral regurgitation

Secondary mitral regurgitation (MR) is a common valvular heart disease. Its prognostic burden in patients suffering from idiopathic or ischemic cardiomyopathy (ICM) with left ventricular (LV) dysfunction/dilation has been clearly demonstrated. Severe secondary MR is associated with an increased mortality and frequent heart failure hospitalizations. Although guideline-directed medical therapy (GDMT) is the cornerstone of the management of secondary MR, a certain proportion of patients remain symptomatic. For these patients, several surgical techniques have been progressively developed during the last few decades (replacement, repair, sub-valvular apparatus interventions and other ventricular approaches). In the absence of evidence-based medicine, the benefits of these surgical procedures remains controversial, leading to a low level of recommendation in the guidelines. One way to anticipate the future is to look to the past. Recent prospective randomized trials evaluated surgical and percutaneous techniques and led to a better understanding of how best to treat this disease. In this article, we aim to describe the saga of the surgical and percutaneous treatments for secondary MR throughout the previous decades.

Multimodality Imaging in Secondary Mitral Regurgitation

Secondary mitral regurgitation (sMR) is characterized by left ventricular (LV) dilatation or dysfunction, resulting in failure of mitral leaflet coaptation. sMR complicates up to 35% of ischaemic cardiomyopathies (1) and 57% of dilated cardiomyopathies (2). Due to the prevalence of coronary artery disease worldwide, ischaemic cardiomyopathy is the most frequently encountered cause of sMR in clinical practice. Although mortality from cardiovascular disease has gradually fallen in Western countries, severe sMR remains an independent predictor of mortality (3) and hospitalization for heart failure (4). The presence of even mild sMR following acute MI reduces long-term survival free of major adverse events (1). Such adverse outcomes worsen as the severity of sMR increases, due to a cycle in which LV remodeling begets sMR and vice versa. Current guidelines do not recommend invasive treatment of the sMR alone as a first-line approach, due to the paucity of evidence supporting improvement in clinical outcomes. Furthermore, a lack of international consensus on the thresholds that define severe sMR has resulted in confusion amongst clinicians determining whether intervention is warranted (5, 6). The recent Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial (7) assessing the effectiveness of transcatheter mitral valve repair is the first study to demonstrate mortality benefit from correction of sMR and has reignited interest in identifying patients who would benefit from mitral valve intervention. Multimodality imaging, including echocardiography and cardiovascular magnetic resonance (CMR), plays a key role in helping to diagnose, quantify, monitor, and risk stratify patients for surgical and transcatheter mitral valve interventions.

Long Term Survival After Surgery for Ischaemic Mitral Regurgitation: A Single Centre Australian Experience

BACKGROUND

Ischaemic mitral regurgitation (IMR) is associated with an increase in both mortality and congestive heart failure in patients undergoing coronary artery bypass grafting (CABG). Intervention for moderate to severe IMR involves either valve repair or replacement. The ideal option is yet to be fully defined with relatively poor long-term survival being noted in the literature.

METHOD

A retrospective observational study was conducted to review the outcomes of patients undergoing CABG in combination with either mitral valve repair (MVr) or mitral valve replacement (MVR) for concurrent coronary artery disease with moderate to severe IMR at The Prince Charles Hospital in Brisbane between the years 2002 to 2015.

RESULTS

One hundred and five (105) patients were included, 81 patients (77%) undergoing CABG and MVr and 24 patients (23%) undergoing CABG and MVR. There was no difference in 30-day mortality between the two groups (1% in MVr and 0% in MVR, p=0.589), however patients in the MVr group were significantly more likely, in univariate and multivariate analysis, to develop at least moderate MR (40% v. 8%, p=0.006). The 5-year survival was 87% and 55% at 10 years.

CONCLUSIONS

In patients undergoing CABG and mitral valve intervention for IMR, long-term mortality remains high. There was no difference in short- or long-term mortality between repair and replacement although recurrence of at least moderate mitral regurgitation was significantly higher with mitral valve repair.

Empirical use of causal inference methods to evaluate survival differences in a real-world registry vs those found in randomized clinical trials

With heighted interest in causal inference based on real-world evidence, this empirical study sought to understand differences between the results of observational analyses and long-term randomized clinical trials. We hypothesized that patients deemed "eligible" for clinical trials would follow a different survival trajectory from those deemed "ineligible" and that this factor could partially explain results. In a large observational registry dataset, we estimated separate survival trajectories for hypothetically trial-eligible vs ineligible patients under both coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI). We also explored whether results would depend on the causal inference method (inverse probability of treatment weighting vs optimal full propensity matching) or the approach to combine propensity scores from multiple imputations (the "across" vs "within" approaches). We found that, in this registry population of PCI/CABG multivessel patients, 32.5% would have been eligible for contemporaneous RCTs, suggesting that RCTs enroll selected populations. Additionally, we found treatment selection bias with different distributions of propensity scores between PCI and CABG patients. The different methodological approaches did not result in different conclusions. Overall, trial-eligible patients appeared to demonstrate at least marginally better survival than ineligible patients. Treatment comparisons by eligibility depended on disease severity. Among trial-eligible three-vessel diseased and trial-ineligible two-vessel diseased patients, CABG appeared to have at least a slight advantage with no treatment difference otherwise. In conclusion, our analyses suggest that RCTs enroll highly selected populations, and our findings are generally consistent with RCTs but less pronounced than major registry findings.

An observational, prospective study on surgical treatment of secondary mitral regurgitation: The SMR study. Rationale, purposes, and protocol

The natural history of secondary mitral regurgitation (MR) is unfavorable. Nevertheless, there are no evidence that its correction can improve the outcome. If from one side the original cause of secondary MR can be such to limit the possibilities of improvement, from the other side it is possible that the surgical technique widely applied to repair, restrictive mitral annuloplasty, is not adequate to correct the regurgitation. The addition of valvular and/or subvalvular techniques has been considered a possible technical solution. However, we do not know the prevalence of each technique, how many times mitral replacement is used to correct secondary MR. This aspect is of particular importance, as we know that a successful mitral repair causes a better left ventricular systolic remodeling than a unsuccessful repair or replacement. This study is a prospective, observational registry, conceived to understand what is done in the real world. Any surgeon will use the technique he thinks the most suitable for the patient. Every year, for 5 years, patients will have a clinical and echocardiographic follow-up, to evaluate the risk factors for a worse result (death, rehospitalization for heart failure, reoperation for MR return, moderate, or more MR return). This knowledge will give us the possibility to understand which is the technique, or the strategy, more efficient to treat this disease and the real efficacy of the surgical treatment.

Percutaneous mitral repair: current and future devices

Mitral regurgitation (MR) is the second most common valvular heart disease and its prevalence is increasing with population ageing. In the recent years we have witnessed the development of several transcatheter devices to correct MR in patients at high-risk for surgery. The majority of evidence regarding safety and efficacy of this new therapy comes from MitraClip studies. However, new alternatives on the field of valve repair have emerged with promising results. The aim of this review is to portrait the landscape of transcatheter mitral repair alternatives, from currently used devices to those that will have a role in the near future.

Cost-effectiveness of coronary artery bypass grafting plus mitral valve repair versus coronary artery bypass grafting alone for moderate ischemic mitral regurgitation

OBJECTIVE

The Cardiothoracic Surgical Trials Network reported that left ventricular reverse remodeling at 2 years did not differ between patients with moderate ischemic mitral regurgitation randomized to coronary artery bypass grafting plus mitral valve repair (n = 150) or coronary artery bypass grafting alone (n = 151). To address health resource use implications, we compared costs and quality-adjusted survival.

METHODS

We used individual patient data from the Cardiothoracic Surgical Trials Network trial on survival, hospitalizations, quality of life, and US hospitalization costs to estimate cumulative costs and quality-adjusted life years. A microsimulation model was developed to extrapolate to 10 years. Bootstrap and deterministic sensitivity analyses were performed to address uncertainty.

RESULTS

In-hospital costs were $59,745 for coronary artery bypass grafting plus mitral valve repair versus $51,326 for coronary artery bypass grafting alone (difference $8419; 95% uncertainty interval, 2259-18,757). Two-year costs were $81,263 versus $67,341 (difference 13,922 [2370 to 28,888]), and quality-adjusted life years were 1.35 versus 1.30 (difference 0.05; -0.04 to 0.14), resulting in an incremental cost-effectiveness ratio of $308,343/quality-adjusted life year for coronary artery bypass grafting plus mitral valve repair. At 10 years, its costs remained higher ($107,733 vs $88,583, difference 19,150 [-3866 to 56,826]) and quality-adjusted life years showed no difference (-0.92 to 0.87), with 5.08 versus 5.08. The likelihood that coronary artery bypass grafting plus mitral valve repair would be considered cost-effective at 10 years based on a cost-effectiveness threshold of $100K/quality-adjusted life year did not exceed 37%. Only when this procedure reduces the death rate by a relative 5% will the incremental cost-effectiveness ratio fall below $100K/quality-adjusted life year.

CONCLUSIONS

The addition of mitral valve repair to coronary artery bypass grafting for patients with moderate ischemic mitral regurgitation is unlikely to be cost-effective. Only if late mortality benefits can be demonstrated will it meet commonly used cost-effectiveness criteria.

Restrictive mitral annuloplasty with or without coronary artery bypass grafting in ischemic mitral regurgitation

Aims

In patients with ischaemic mitral regurgitation (MR), the impact of mitral valve surgery with concomitant coronary artery bypass grafting (CABG) on post‐operative survival and left ventricular (LV) reverse remodelling remains unknown. Therefore, we investigated these outcomes following restrictive mitral annuloplasty (RMA) with and without CABG in those patients.

Methods and results

This study included 309 patients with chronic MR and ischaemic cardiomyopathy for whom concomitant CABG was indicated (n = 225) or not indicated (n = 84) with RMA. The primary endpoint was all cause mortality during the follow‐up, and the secondary endpoint was defined as the composite of mortality and re‐admission for heart failure. Linear mixed model was used to analyse serial echocardiographic changes in LV function. To reduce the impact of treatment bias and potential confounding in the direct comparisons between patients who underwent RMA with and those who underwent it without CABG, we established weighted Cox proportional‐hazards regression models with inverse‐probability‐of‐treatment weighting. Pre‐operatively, there were no intergroup differences in age (RMA with CABG, 67 ± 9 vs. RMA without CABG, 68 ± 11, P = 0.409) and logistic EuroSCORE II (16 ± 14 vs. 15 ± 15%, P = 0.496). The 30‐day mortalities were 2.7% and 3.6%, respectively (P = 0.67). During follow‐up with a mean duration of 72 ± 37 months (range, 5.6–179), there were 157 deaths and 105 re‐admissions for heart failure. Overall 1‐year and 5‐year survival rates were 83 ± 2% and 58 ± 3%, respectively. Patients who did not receive CABG with RMA had a significantly lower 5‐year survival rate (45% vs. 63%, P = 0.049) and freedom from adverse events defined as mortality and/or admission for heart failure (19% vs. 43%, P < 0.001) than those who did. After adjustments for clinical covariates with inverse‐probability‐of‐treatment weighting, concomitant CABG was identified as an independent protective factor for adverse events (hazard ratio: 0.53; 95% confidence interval: 0.44–0.64; P < 0.001). Along with significant MR reduction, LV function parameters changed over time after surgery in both groups, with greater improvements in patients who underwent RMA with CABG (time effect, P < 0.001; and interaction effect, P = 0.002).

Conclusions

RMA can be performed with an acceptable operative mortality, irrespective of indications for CABG. Patients with ischaemic MR for whom CABG is indicated with RMA are more likely to show better long‐term and event‐free survival and greater improvements in LV systolic function. The optimal revascularization strategy should be discussed with a heart team whenever indicated in patients with ischaemic MR; otherwise, they may miss the opportunity to benefit from concomitant CABG during subsequent RMA.

Diagnosis and Management of Ischemic Mitral Regurgitation: Evidence-Based Clinical Decision Making at the Point of Care

Anatomical, functional, and pathophysiologic mechanisms of ischemic mitral regurgitation (IMR) are markedly different from the primary mitral regurgitation. The older and ubiquitous cutoff of EROA (effective regurgitant orifice area) and Rvol (regurgitant volume) for IMR has been reinstated in the new guideline after a brief hiatus. There had always been a lack of good-quality evidence for its introduction for guiding IMR severity in the previous guideline, and we still do not have quality evidences that could justify its reintroduction. Unlike primary MR, IMR is usually associated with reduced ejection fraction. Therefore, it appears unrealistic to keep the similar cutoff for primary MR and IMR. The cutoff of severity can be modified according to projected values of Rvol normalized to ejection fraction and EROA normalized to Rvol. In addition, the treatment outcome in these patients is determined by factors (left ventricular dyssynchrony, annular dilatation, tenting area, tenting height, tenting volume, and myocardial viability) other than the simple grading. In this review article, a series of graph have been constructed from the numerical data derived from the literatures on IMR to depict the relationship between EROA, Rvol, left ventricular end diastolic volume, and ejection fraction in order to obtain a reasonable projection formula for EROA and Rvol. Furthermore, a management algorithm has been proposed for patients with IMR undergoing coronary artery bypass grafting based on echocardiographic predictors that influence the postoperative outcome.

Predictive impact of previous coronary artery bypass grafting on mortality after MitraClip implantation for ischemic functional mitral regurgitation

BACKGROUND

Many candidates with ischaemic functional mitral regurgitation (FMR) have previously undergone coronary artery bypass grafting (CABG), in which transcatheter mitral valve repair can be reasonable for ameliorating the deteriorated hemodynamic and heart failure symptoms. We sought to elucidate the outcomes of MitraClip (MC) implantation in patients with symptomatic ischaemic FMR after CABG.

METHODS

We investigated clinical characteristics, outcomes and predictive impact of previous CABG on mortality in ischaemic FMR patients who underwent MC implantation from two high-volume centres in Germany.

RESULTS

We enrolled 159 patients who previously underwent CABG. Compared with a reference group that did not previously undergo CABG (n = 182), the cohort consisted of more elderly patients (75.0, standard deviation [SD] 7.7 versus 72.9, SD 9.6 years, p = 0.028), more men (84% vs. 69%, p < 0.001), and reduced tricuspid annular plane systolic excursion (14.0, SD 4.0, vs. 16.6, SD 4.6 mm, p < 0.0001). The CABG group showed similar outcomes regarding procedural success (91% vs. 94%, p = 0.24) and 30-day mortality (5.0% vs. 6.0%, p = 0.68), but worse survival after MC implantation (log-rank p = 0.019, hazard ratio 1.56 [95% confidence interval (CI) 1.08-2.26]). After propensity score matching (n = 224), the hazard ratio was 1.18 [95%CI 0.76-1.84] without statistical significance (p = 0.46).

CONCLUSIONS

Transcatheter mitral valve repair using the MC is a viable treatment option for patients with symptomatic ischaemic FMR after CABG. Although the baseline characteristics seemed to point to sick patients, CABG itself had only a modest impact on survival.

Experience of the management of coronary artery bypass graft only on moderate ischemic mitral regurgitation: A single-center retrospective study

To summary the impact of off-pump coronary artery bypass grafting (CABG) only on patients with moderate ischemic mitral regurgitation and survival.We retrospectively analyzed 109 patients with coronary artery disease (CAD) complicated by moderate mitral regurgitation, from January, 2008 to December, 2014, in the Department of Cardiovascular Surgery at the No. 2 Hospital of Jilin University undergoing off pump CABG only. Preoperative clinical characteristics, complications after surgery, and outcome (survivor or death) were assessed. We observed the degree of mitral valve regurgitation, left ventricular ejection fraction (LVEF), left ventricular and left atrial size, left ventricular end-diastolic volume (LVEDV) preoperative, and New York Heart Association (NYHA) functional class, postoperative 10 days before discharge, and 6 months and longer after surgery. The statistical data were processed by SPSS 19 software with computer; statistical significant difference with P < .05.Overall in-hospital mortality was 2.75% (3 patients). Patients had lower mean LVEF in the postoperative compared with the preoperative period, but all the patients had higher LVEF since 6 months than preoperative period (P < .001). Compared with the preoperative dates, postoperative valvular regurgitation, left ventricular and atrial size and LVEDV postoperative 10 days before discharge, 6 months and more longer after surgery reduced significantly (P < .001). Rapid atrial fibrillation occurred in 19 cases during perioperative and returned to normal before discharge. The symptom of angina was disappeared in all patients before discharge. The mean follow-up time was 60.16 ± 17.98 months (range 36-96 months). Two patients died of major adverse cardiac events including heart failure and ventricular fibrillation. Three patients died of lung cancer, and 2 patients died of stroke during the longer follow-up.Off-pump CABG can be performed safely in patients with CAD complicated by moderate mitral regurgitation. The efficacy of CABG only is well demonstrated by the significant improvement of LVEF and NYHA functional class, and by the decrease of left ventricular and atrial size, LVEDV, and mitral regurgitation grade.

Differential Impact of Mitral Valve Repair on Outcome of Coronary Artery Bypass Grafting With or Without Surgical Ventricular Reconstruction in the Surgical Treatment for Ischemic Heart Failure (STICH) Trial

Background

This study examined the impact of mitral valve repair (MVRe) on survival of patients with moderate or severe (≥2+) MR and ischemic cardiomyopathy randomized to coronary artery bypass grafting (CABG) versus CABG+surgical ventricular reconstruction (SVR) in the STICH trial.

Methods

Among patients with moderate or severe MR and ischemic cardiomyopathy undergoing CABG or CABG+SVR, the impact of MVRe on mortality between the two treatment arms was compared.

Results

Among 867 patients with assessment of baseline MR severity, 211 had moderate or severe MR. After excluding 7 patients who underwent mitral valve replacement, 50, 44, 62, and 48 patients underwent CABG, CABG+MVRe, CABG+SVR, and CABG+SVR+MVRe, respectively. Four-year mortality rates were lower following CABG+MVRe than CABG alone (16% vs. 55%; adjusted hazard ratio [HR] 0.30; 95% CI 0.13-0.71). In contrast, the CABG+SVR+MVRe and CABG+SVR groups had similar 4-year mortality of 39% vs. 39% (adjusted HR 0.88; 95% CI 0.46-1.70). MVRe had a more favorable effect on survival in patients undergoing CABG alone compared to CABG+SVR (p=0.013). Baseline MR severity was similar between patients that received CABG+MVRe and those that underwent CABG+SVR+MVRe. A larger proportion of patients demonstrated a reduction in MR between 4 and 24 months after CABG+MVRe compared to CABG+SVR+MVRe (50.0% versus 25.0%, p=0.023).

Conclusion

In patients with moderate or severe MR and ischemic cardiomyopathy undergoing CABG, MVRe appears to have a favorable effect on survival. The addition of SVR to CABG may attenuate the anticipated benefits of MVRe by limiting the long-term reduction of MR with MVRe.

Long-term outcomes of mitral regurgitation by type and severity

BACKGROUND

We aimed to determine the association of MR severity and type with all-cause death in a large, real-world, clinical setting.

METHODS

We reviewed full echocardiography studies at Duke Echocardiography Laboratory (01/01/1995-12/31/2010), classifying MR based on valve morphology, presence of coronary artery disease, and left ventricular size and function. Survival was compared among patients stratified by MR type and baseline severity.

RESULTS

Of 93,007 qualifying patients, 32,137 (34.6%) had ≥mild MR. A total of 8094 (8.7%) had moderate/severe MR, which was primary myxomatous (14.1%), primary non-myxomatous (6.2%), secondary non-ischemic (17.0%), and secondary ischemic (49.4%). At 10 years, patients with primary myxomatous MR or MR due to indeterminate cause had survival rates of >60%; primary non-myxomatous, secondary ischemic, and non-ischemic MR had survival rates <50%. While mild (HR 1.06, 95% CI 1.03-1.09), moderate (HR 1.31, 95% CI 1.27-1.37), and severe (HR 1.55, 95% CI 1.46-1.65) MR were independently associated with all-cause death, the relationship of increasing MR severity with mortality varied across MR types (P ≤ .001 for interaction); the highest risk associated with worsening severity was seen in primary myxomatous MR followed by secondary ischemic MR and primary non-myxomatous MR.

CONCLUSIONS

Although MR severity is independently associated with increased all-cause death risk for most forms of MR, the absolute mortality rates associated with worse MR severity are much higher for primary myxomatous, non-myxomatous, and secondary ischemic MR. The findings from this study support carefully defining MR by type and severity.

Repair or replacement for severe ischemic mitral regurgitation: A meta-analysis

BACKGROUND

The best surgical option for severe ischemic mitral regurgitation (IMR) is still controversial. The aim of this study was to perform a meta-analysis to compare the clinical outcomes of mitral valve repair (MVP) with replacement (MVR).

METHODS

A literature search was conducted in PubMed, Embase, and Medline using the terms "ischemic mitral regurgitation" and "repair or annuloplasty or reconstruction" and "replacement" in the title/abstract field. The primary outcomes of interest were perioperative mortality and long-term survival. Secondary outcomes were mitral regurgitation (MR) recurrence and reoperation.

RESULTS

Of 276 studies, 13 studies met the inclusion and exclusion criteria. A total of 1993 patients were included in these studies, consisting of 1259 (63%) repair cases, and 734 (37%) replacement cases. Perioperative mortality was lower with MVP compared with MVR [OR 0.61; (95% CI, 0.43-0.87; P < .05)]. There was no difference with respect to long-term survival [HR 0.75; (95% CI, 0.52-1.09; P = .14)] and reoperation [OR 0.77; (95% CI, 0.38-1.57; P = .47)]. MVP is associated with a higher recurrence of MR [OR = 4.09; (95% CI, 1.82-9.19; P < .001)].

CONCLUSION

MVP is associated with a lower perioperative mortality but a higher recurrence of MR compared with MVR for severe IMR. No differences were found with respect to long-term survival and reoperation.

Mitral valve repair versus replacement in patients with ischemic mitral regurgitation

Background

The optimal management of ischemic mitral regurgitation (IMR) is controversial. The aim of this study was to examine our eight years' experience of surgical treatment in patients with IMR, and to compare outcomes of mitral valve repair versus replacement with concomitant coronary artery bypass grafting (CABG).

Methods

A retrospective, observational, cohort study was undertaken to collect data on consecutive patients with IMR and coronary artery disease who received CABG and mitral valve surgery in our hospital between January 2008 and December 2015. Basic patient characteristics, operative data, and postoperative clinical outcomes were examined.

Results

The series included 22 consecutive patients (21 male; 1 female). The mean age was 62.1±11.4 years old. The mean preoperative left ventricular ejection fraction (LVEF) was 33.4%±15.4%. The mean cardiopulmonary bypass (CPB) time was 165.4±38.4 minutes, and the mean aortic cross clamp time was 113.8±33.6 minutes. Eighteen patients underwent CABG plus mitral valve repair, and four patients underwent CABG plus mitral valve replacement (MVR). There were three early in-hospital mortalities: two in the mitral valve repair group, and one in the replacement group. The follow-up was complete in all patients, with a mean follow-up duration of 3.1±2.3 years. The mean last LVEF was 35.3%±17.7%. There were 2 late mortalities. Both were from the repair group. The overall late survival rate was 81.6%, with 83.0% in the repair group and 75.0% in the replacement group. In patients with echocardiography follow-up of more than or equal to 1 year duration, the residual or recurrent mitral regurgitation rates were 0.0% in the replacement group and 57.1% in the repair group. One patient in the repair group later underwent MVR due to severe regurgitation postoperatively.

Conclusions

Our preliminary findings showed that the surgical outcome of mitral valve repair might be comparable to that of MVR in terms of early mortality and long-term survival. However, mitral valve repair was associated with a higher residual or recurrent mitral regurgitation rate. According to the latest literature, the role of MVR can justifiably be indicated for severe IMR. As for moderate IMR, CABG alone without mitral valve intervention may provide similar clinical outcomes.

Functional mitral regurgitation: an overview for surgical management framework

Functional mitral regurgitation (FMR) is one the most common complications of myocardial infarction (MI) in adults carrying a significant clinical and economic burden. Despite specific randomized controlled studies to address its treatment have been performed, there are still a number of questions remained unanswered. Outcomes of surgical repair of FMR are still hampered by a significant rate of recurrence of regurgitation and need for reoperation. Mechanisms underlying failure of repairs still need to be completely clarified and questions regarding the indications and optimal timing for intervention as well as the best suitable operative technique to be applied are still debated. This work will review the current knowledge on FMR including its pathogenic mechanisms, the available treatment strategies, the evidences from trials and observational studies and the potential future directions to address the issues related to its treatment.

Should the mitral valve be repaired for moderate ischemic mitral regurgitation at the time of revascularization surgery?

BACKGROUND

Ischemic mitral regurgitation (IMR) is associated with increased mortality and recurrent congestive heart failure following coronary artery bypass graft (CABG) surgery. While mitral surgery should be undertaken for severe MR during CABG, the treatment of moderate IMR remains controversial. We conducted a meta-analysis to determine the outcomes of CABG alone and combine with mitral valve repair (MVr) in moderate IMR.

METHODS

A literature search was conducted by Pubmed, Ovid, and Embase, which included 643 articles. Eleven studies (seven observational studies and four randomized controlled trials) with a total of 1406 patients were included (CABG alone = 864 and CABG plus MVr = 542).

RESULTS

There was no difference in operative mortality (odds ratio 1.56, 95% confidence interval [CI] 0.92-2.71) or long-term survival at 1 or 5 years (hazard ratio 0.98, 95%CI 0.71-1.35, P = 0.49) between the two groups, and little evidence of heterogeneity was found in the studies (I²  = 0.0, P = 0.562). There was significantly greater improvement in MR grade (weighted mean difference [WMD] -1.15, 95%CI -1.67 to -0.064, P = < 0.001) and left ventricular systolic diameter (WMD -3.02, 95%CI -4.85 to -1.18, P = 0.001) following CABG and MVr compared to CABG alone. No difference in postoperative functional class or ejection fraction was found.

CONCLUSIONS

Our results show that in the presence of moderate IMR, adding MVr to revascularization reduces MR grade on follow-up echocardiography and promotes ventricular remodeling, with no improvement in long-term survival or functional class.

OPCABG for Moderate CIMR in Elderly Patients: a Superior Option?

OBJECTIVE

To compare the early and late outcomes of off-pump coronary artery bypass grafting and coronary artery bypass graft + mitral valve repair in elderly patients with moderate chronic ischemic mitral regurgitation.

METHODS

One hundred and fifty elderly (age > 70 years) patients with moderate chronic ischemic mitral regurgitation who underwent off-pump coronary artery bypass grafting (n=95) or coronary artery bypass graft + mitral valve repair (n=55) between January 2007 and December 2014 were studied. They were subdivided according to presence or absence of high operative risk. Peri-operative variables and early operative outcomes were retrospectively studied. Survival, mitral regurgitation grade, and functional outcomes were prospectively analysed.

RESULTS

Both groups were comparable in terms of age (P=0.23), sex (P=0.74), left ventricle ejection fraction (P=0.6) and preoperative functional class (P=0.52). The mean number of grafts for off-pump coronary artery bypass grafting group was 3.14 and coronary artery bypass graft + mitral valve repair was 3.21. Off-pump coronary artery bypass grafting group had statistically significant better early operative outcomes i.e perioperative blood transfusions, intraaortic balloon pump usage, arrhythmias, renal dysfunction, liver dysfunction, sepsis, mean hours of ventilation, intensive care unit stay and operative mortality. On a prospective follow up of 5±2.33 years (1-9 years), coronary artery bypass graft + mitral valve repair in low operative risk subgroup had better improvements in mitral regurgitation grade than off-pump coronary artery bypass grafting. Both groups had similar improvements in functional class and cumulative survival was also comparable (63.2% vs. 54.5%).

CONCLUSION

Off-pump coronary artery bypass grafting is a safer alternative to coronary artery bypass graft + mitral valve repair with better early operative outcomes and comparable late survival and functional outcomes in elderly patients with moderate chronic ischemic mitral regurgitation, especially those with higher operative risk.

Moderate ischemic mitral regurgitation: coronary artery bypass grafting with versus without simultaneous treatment of the mitral valve

BACKGROUND

Ischemic mitral regurgitation (IMR) is a frequent complication of coronary artery heart disease and is associated with increased mortality. Controversies exists whether patients with moderate IMR may benefit from a combined procedure with coronary artery bypass grafting (CABG) and treatment of mitral regurgitation.

METHODS

451 patients with moderate IMR (grade 2) receiving either CABG alone (CABG only) or additional mitral valve repair or replacement (CABG+MV) were included in this observational single-centre study. Patients were matched according to the number of bypass grafts, preoperative NYHA functional class and age. In total, 42 patients (21 CABG only, 21 CABG+MV) were analysed.

RESULTS

The mean follow-up was 4.3±1.9 years. CABG alone reduced the IMR grade to 1.2±0.5, whereas the combined procedure resulted in a decrease to 0.6±0.7 (P=0.039). NYHA functional class was reduced from grade 2.8±0.6 to 1.6±0.5 (CABG only) and 2.0±1.1 (CABG+MV, P=0.55). Three- and five-year survival rates were 71% and 53% in the CABG only group compared to 60% both after 3 and 5 years in the CABG+MV group (P=0.89).

CONCLUSIONS

In this observational study, combined CABG and surgical treatment of moderate IMR was associated with a more effective reduction of IMR than CABG alone. No statistically significant differences in survival or NYHA functional class were observed. Further studies will need to investigate the value of additional mitral valve surgery in moderate IMR.

Prognosis of patients with secondary mitral regurgitation and reduced ejection fraction

Objective

The impact of the severity of secondary mitral regurgitation (MR) on the risk of death and heart failure (HF) hospitalisations in patients with reduced left ventricular (LV) systolic function is poorly defined. The study sought to identify the incremental risk of secondary MR in patients with reduced LV systolic function.

Methods

We studied 615 consecutive patients with LV ejection fraction ≤35% by transthoracic echocardiography at a single medical centre. Patients were divided into three groups of no MR, mild, or moderate to severe MR. The median follow-up was 2.9 years. The primary endpoint was a composite of death or HF hospitalisations.

Results

Compared with patients with no MR, the risk of death or HF hospitalisations was higher for mild MR (HR 1.7, P=0.003) and moderate to severe MR (HR 2.7, P<0.001). The risk was also higher for the component endpoints of HF hospitalisations (mild MR: HR 2.3, P=0.001; moderate to severe MR: HR 3.5, P<0.001) and death (mild MR: HR 1.6, P=0.033; moderate to severe MR: HR 2.6, P<0.001). After adjustment for other covariates, MR was no longer significantly associated with death or HF hospitalisations, or death alone, but remained significantly associated with HF hospitalisations (mild MR: HR 1.7, P=0.028; moderate to severe MR: HR 2.2, P=0.002).

Conclusions

In patients with reduced LV systolic function, secondary MR is associated with an increased risk of HF hospitalisations but not death.

Predictors of Mortality in Patients With Severe Ischemic Cardiomyopathy Undergoing Surgical Mitral Valve Intervention

Background

Ischemic mitral regurgitation is associated with substantial risk of death. Although surgical mitral valve intervention (MVi) may improve symptoms, it has not been shown to improve survival. The aim of this study was to identify predictors of mortality in patients with ischemic mitral regurgitation and MVi.

Methods and Results

We evaluated 117 consecutive patients (age, 65±10 years) with advanced ischemic cardiomyopathy who underwent cardiac magnetic resonance and subsequent MVi between January 1, 2002 and January 1, 2012. Cardiac magnetic resonance was used to assess left ventricular remodeling and myocardial scarring. The effective regurgitant orifice area was calculated from the proximal isovelocity surface area by echocardiography. There were 43 deaths (37%) during follow‐up (median, 62 months). On multivariable analysis, age ≥70 years (P=0.013), diabetes mellitus (P=0.001), dyslipidemia (P=0.012), papillary muscle scar (P=0.010), incomplete revascularization (P=0.001), and total scar %×effective regurgitant orifice area ≥0.20 cm² (P=0.005) were each independently associated with all‐cause mortality. Although patients with effective regurgitant orifice area <0.2 cm² at baseline demonstrated an increased hazard ratio of 3.3 for every 10% increase in scar, the hazard ratio increased to 9 for every 10% increase in scar in those with baseline effective regurgitant orifice area ≥0.20 cm². Mortality also was significantly higher in patients with incomplete revascularization compared with those with vascularized viable myocardium (61% versus 28%; P<0.001).

Conclusions

Increased total scar burden and the presence of incomplete revascularization are powerful predictors of mortality in patients with advanced ischemic cardiomyopathy undergoing MVi. Viability assessment with cardiac magnetic resonance imaging can identify which patients with ischemic mitral regurgitation are at highest risk for mortality after surgical MVi.

Baseline mitral regurgitation predicts outcome in patients referred for dobutamine stress echocardiography

A number of parameters recorded during dobutamine stress echocardiography (DSE) are associated with worse outcome. However, the relative importance of baseline mitral regurgitation (MR) is unknown. The aim of this study was to assess the prevalence and associated implications of functional MR with long-term mortality in a large cohort of patients referred for DSE. 6745 patients (mean age 64.9 ± 12.2 years) were studied. Demographic, baseline and peak DSE data were collected. All-cause mortality was retrospectively analyzed. DSE was successfully completed in all patients with no adverse outcomes. MR was present in 1019 (15.1%) patients. During a mean follow up of 5.1 ± 1.8 years, 1642 (24.3%) patients died and MR was significantly associated with increased all-cause mortality (p < 0.001). With Kaplan-Meier analysis, survival was significantly worse for patients with moderate and severe MR (p < 0.001). With multivariate Cox regression analysis, moderate and severe MR (HR 2.78; 95% CI 2.17-3.57 and HR 3.62; 95% CI 2.89-4.53, respectively) were independently associated with all-cause mortality. The addition of MR to C statistic models significantly improved discrimination. MR is associated with all-cause mortality and adds incremental prognostic information among patients referred for DSE. The presence of MR should be taken into account when evaluating the prognostic significance of DSE results.

Surgical Treatment of Ischemic Mitral Regurgitation: Valve Repair Versus Replacement

PURPOSE OF REVIEW

Ischemic mitral regurgitation (MR), which occurs in about 20-30% patients with a prior myocardial infarction, is associated with worsening heart failure and an increase in cardiovascular mortality. It should be treated surgically if certain hemodynamic severity criteria are met and in patients who continue to experience symptoms of heart failure despite optimal medical therapy. However, current guidelines do not suggest which of the available approaches to mitral valve surgery-mitral valve (MV) repair or replacement (MVR) is superior for this indication. While MV repair is reported to confer improved survival, MVR may provide higher rates of freedom from recurrent MR. This article attempts to provide the reader with a comprehensive review and comparison of current techniques of mitral valve surgery in patients with severe ischemic MR.

RECENT FINDINGS

The first randomized trial to compare MV repair versus MVR in patients with severe ischemic MR, the Cardiothoracic Surgical Trials Network (CTSN) trial, was recently concluded and reported no significant difference in the primary outcome of left ventricular end systolic volume index between the two approaches at either 1- or 2-year follow-ups. Data comparing approaches of MV repair and MVR for ischemic MR is largely limited to small, non-randomized retrospective trials. The only randomized trial data to examine this issue suggested no difference in mortality with either MVR or MV repair; however, MVR was shown to be consistently associated with higher rates of MR recurrence. Certain echocardiographic features have been reported to predict poor outcomes with MVR and may help refine the selection of the surgical approach in the individual patient.

Meta-Analysis of Usefulness of Concomitant Mitral Valve Repair or Replacement for Moderate Ischemic Mitral Regurgitation With Coronary Artery Bypass Grafting

Moderate ischemic mitral regurgitation (MR) is often present in patients undergoing coronary artery bypass grafting (CABG). However, the clinical benefit of repairing moderate MR during CABG is unproven. We searched multiple databases to identify original studies comparing isolated CABG versus combined CABG and MR surgery (mitral valve surgery with coronary artery bypass grafting [MVCABG]); survival (either early or midterm) was the primary end point. Risk ratio (RR) or standardize mean difference was selected as the effect estimates; survival was compared by pooling hazard ratios. All results are presented with 95% CIs; p <0.05 is statistically significant. Eleven studies (7 retrospective and 4 randomized controlled trials; 547 MVCABG and 900 CABG patients) were included in our meta-analysis. Concomitant mitral valve repair significantly prolonged surgical duration (p <0.01). Early mortality (MVCABG 6.9% and CABG 6%) was comparable (RR 1.3 [0.9 to 1.8]; p = 0.11). At follow-up, the MVCABG patients had similar New York Heart Association class (standardize mean difference -0.73 (-1.64 to 0.18; p = 0.11). However, patients who underwent concomitant mitral valve surgery had less MR at follow-up (recurrent significant MR, RR 0.37 [0.22 to 0.62]; p = 0.001; mean MR grade, mean difference = 0.39 [0.26 to 0.59]; p <0.001). Midterm survival rate (mean follow-up 5 years) was comparable in both groups (hazard ratio for mortality in the MVCABG cohort 1.1 [0.9 to 1.3]; p = 0.38). In conclusion, concomitant repair of moderate ischemic MR leads to improved mitral valve competence at follow-up; however, this was not translated into any functional or survival benefit for adding valve repair to CABG for these patients at 5 years of follow-up.

Ischemic mitral valve prolapse

Ischemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third among the patients undergoing surgery for ischemic mitral regurgitation (IMR). IMP is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. IMP is not only a disorder of valvular function, but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension and a correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localization of prolapse, anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient's outcomes. This review will summarize our current understanding of the pathophysiology and clinical evidence on IMP with a particular focus on the surgical treatment.

Functional Mitral Regurgitation: Appraising the Evidence Behind Recommended Treatment Strategies

Functional mitral regurgitation (MR) is the most common type of MR encountered in clinical practice. Because the disease arises from the ventricular aspect of the mitral valve apparatus, treatment therapies are less defined and outcomes are poor. In this review, the state of evidence for medical and surgical therapy in functional MR is appraised. Future directions for research in this area are also defined.