Coronary artery bypass surgery with or without mitral valve annuloplasty in moderate functional ischemic mitral regurgitation: final results of the Randomized Ischemic Mitral Evaluation (RIME) trial

Moderate Chronic Ischemic Mitral Regurgitation

The benefits of concomitant mitral valve procedure (MVP) for treating moderate chronic ischemic mitral regurgitation (IMR) during coronary artery bypass grafting (CABG) have not been clearly established. This study aimed to determine the incidence of moderate or more residual mitral regurgitation (MR) following CABG plus MVP for moderate chronic IMR, and to evaluate the impacts of concomitant MVP vs. CABG alone on clinical outcomes based on propensity-matched data.All eligible patients were entered into either the MVP group (CABG plus MVP, n = 184) or CABG group (CABG alone, n = 162). Moderate or more residual MR rate was investigated, and in-hospital and follow-up outcomes between the groups were compared after matching.Moderate or more residual MR rate was 11.4% at 1 year and 22.9% at 2 years after CABG plus MVP, respectively. Patients in the MVP group as compared with the CABG group had significantly lower moderate or more residual MR rates at various postoperative time points (all P < 0.001). Grouping was not an independent risk factor for in-hospital adverse events in multivariate logistic regression analysis. Also, grouping was a significant variable related to moderate or more residual MR rate and NYHA class III-IV at the latest follow-up in Cox regression analysis (HR = 0.391, 95% CI 0.114-0.628; HR = 0.419, 95% CI 0.233-0.819, respectively).Concomitant MVP as compared with CABG alone for treating moderate chronic IMR was associated with a reduction in moderate or more residual MR rate and an improvement in NYHA functional status, with no increase in in-hospital adverse events or follow-up death.

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.

Surgical intervention for ischemic mitral regurgitation: how can we achieve better outcomes?

Ischemic mitral regurgitation (MR) is a common complication of myocardial infarction. Left ventricular (LV) dysfunction and distortion of the subvalvular apparatus are the main contributors to ischemic MR. Coronary artery bypass grafting alone, mitral valve replacement, and mitral valve repair, with or without subvalvular procedures, have been performed for moderate-to-severe ischemic MR. Several randomized studies on the surgical treatment of ischemic MR have been performed; however, the optimal surgical strategy remains controversial because none have demonstrated a clear survival benefit. Since the mechanisms of ischemic MR are complex and multifactorial, comprehensive preoperative assessment of LV function and geometry (both global and regional), mitral valve configuration, viability testing, and exercise echocardiography are needed. A better understanding of this complicated disease and of the advantages and limitations of each procedure may help us devise more effective patient-specific surgical treatment strategies and achieve better outcomes.

Ischemic Mitral Regurgitation: Current Understanding and Surgical Options

Secondary, or functional, mitral regurgitation (MR) occurs with impaired coaptation of structurally normal valve leaflets due to abnormal structure and/or function of the left ventricle (LV). A leading cause of functional mitral regurgitation is ischemic cardiomyopathy, resulting in left ventricular dysfunction and subsequent congestive heart failure (CHF) and ischemic mitral regurgitation (IMR). The value of surgical or transcatheter correction of IMR remains controversial, since the underlying pathology of IMR is attributed to a dysfunctional left ventricle. However, even mild IMR has been shown to be harmful to CHF patients, as IMR is both a surrogate of advanced CHF and an independent contributor to CHF morbidity and mortality. While observational and randomized studies have examined surgical treatment of IMR with conflicting outcomes, additional well-designed randomized controlled trials should be performed to further clarify the optimal treatment for IMR. Additionally, close attention should be paid to the quality of interventions performed, as durable reduction in IMR provides the best hope of a positive clinical outcome. This review focuses on the pathophysiology of IMR, current evidence regarding surgical and transcatheter interventions, and future directions in management of IMR.

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.

"RFEF" and mitral regurgitation jet direction: surrogate markers for likelihood of left ventricle reverse remodeling in patients with moderate chronic ischemic mitral regurgitation

Purpose

Surgical management of moderate chronic ischemic mitral regurgitation (CIMR) is controversial. We propose a simplified classification of moderate CIMR based on regurgitant fraction (RF), ejection fraction (EF), and jet direction (central/eccentric) to predict left ventricle (LV) remodeling and identify patient subsets which need mitral valve (MV) repair along with coronary artery bypass grafting (CABG).

Methods

In this prospective controlled study (n = 210), patients with moderate CIMR were randomized. Group I (n = 106) underwent off-pump CABG alone while group II (n = 104) underwent CABG + MV repair. The product of regurgitation fraction and ejection fraction ("RFEF") was taken as a surrogate for myocardial reserve. The cut-off defined was 0.12; patients with RFEF ≤ 0.12 were categorized as the "bad" and those with RFEF > 0.12 as the "good" subset. The patients were further subdivided on the basis of their mitral regurgitation (MR) jet direction (central/eccentric). The percentage improvement in left ventricular end-systolic volume index (LVESVI) and MR grade were recorded 6 monthly.

Results

Analysis of the continuous variable "RFEF" in conjunction with jet direction was performed. At 12 months, the patient in good subset with central direction of jet showed improvement in LVESVI % in both groups (p = 0.428), while the patients in bad subset with eccentric direction of jet showed significantly higher improvement in LVESVI %, group II as compared to group I (p = 0.004).

Conclusion

This study thus identifies "RFEF" as a surrogate for reverse remodeling capacity. In association with MR jet direction, predicts the subset of moderate CIMR patients most likely to have maximum LVESVI and MR grade reduction.

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.

Chronic ischemic mitral valve regurgitation and surgical perspectives

Chronic ischemic mitral valve regurgitation is a result of disturbed left ventricular geometry secondary to myocardial ischemia in the absence of intrinsic mitral valve pathology. It is a common complication after myocardial infarction, and patients who have ischemic mitral regurgitation (IMR) have a worse prognosis compared to patients who have ischemic heart disease alone, and this is directly related to the severity of IMR. Medical therapy has limited efficacy, and surgical options including various repair techniques and valve replacement had been tried with variable success. Still there is intense debate among surgeons whether to interfere with moderate degree IMR at the time of coronary artery revascularization.

Concomitant mitral valve surgery in patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting

Background

The clinical benefits of a concomitant mitral valve (MV) surgery in patients with moderate ischemic mitral regurgitation (iMR) undergoing coronary artery bypass grafting (CABG) remain controversial.

Methods

The study involved 710 patients (mean age, 65.0±8.9 years; 504 males) with moderate iMR undergoing CABG between 1990 and 2015. Of these, 116 (16.3%) patients underwent a concomitant MV surgery (MVS; replacement in 10, repair in 106) and 594 (83.7%) underwent CABG only. Clinical and echocardiographic outcomes were compared before and after adjustment with the use of propensity score (PS) analyses.

Results

Early mortality occurred in 22 (3.7%) and 13 (11.2%) patients in CABG-only and CABG with MVS group, respectively (P=0.001). After adjustment, CABG with MVS group showed significantly increased risks of early death (P<0.001), low cardiac output syndrome (LCOS) (P=0.001) and surgical bleeding (P=0.014). During a median follow-up of 78.0 months (quartile 1-3, 33.6-115.9 months), overall mortality occurred in 286 (40.3%) patients. The addition of an MV surgery showed an increased risk of overall mortality [hazard ratio (HR), 1.34; 95% confidence interval (CI), 0.99-1.80; P=0.055], which became comparable 1 year after surgery on landmark survival analysis (HR, 0.94; 95% CI, 0.64-1.39; P=0.772). Improved left ventricular (LV) ejection fraction and LV reverse remodeling were observed in both groups without significant intergroup differences.

Conclusions

The addition of a concomitant MV surgery increased the risk of early mortality and complications in patients with moderate iMR undergoing CABG. In long-term clinical and echocardiographic outcomes, a concomitant MV surgery seemed to confer no significant clinical benefits.

Contemporary Management of Ischemic Mitral Regurgitation: A Review

Ischemic mitral regurgitation occurs relatively frequently in patients with coronary artery disease and is associated with an increased long-term risk. The pathophysiology of ischemic mitral regurgitation is vexing and poses both diagnostic and therapeutic challenges, leading to the need for a comprehensive, multidisciplinary approach. The management is largely focused on medical therapy, and for those eligible, coronary revascularization or cardiac resynchronization therapy may be considered. In select patients, mitral valve surgery or catheter-based therapy may be undertaken with careful consideration of the underlying pathophysiology, surgical risk, and expected long-term outcomes. The appropriate evaluation of patients with ischemic mitral regurgitation involves a careful multidisciplinary approach that carefully considers symptomatology, the etiology and severity of the mitral regurgitation, and the assessment of comorbidities and operative risk to individualize the care of these patients.

Left ventricular regional dyssynchrony predicts improvements in moderate ischaemic mitral regurgitation after off-pump coronary artery bypass

OBJECTIVES

The aim of this study was to explore the predictors of the improvement in moderate ischaemic mitral regurgitation (IMR) after off-pump coronary artery bypass grafting (OPCAB) focusing on left ventricular (LV) dyssynchrony.

METHODS

A prospective study was performed among 135 patients (age at surgery, mean ± SD: 67.0 ± 8.2 years, 33.3% women) with prior myocardial infarction and moderate IMR undergoing OPCAB from 2008 to 2015. Preoperative and follow-up clinical and echocardiographic parameters were analysed, focusing on LV global/regional dyssynchrony. Patients were grouped by IMR at 1 year postoperatively: improved group with no or mild IMR (n = 61) and failure group with moderate or severe IMR (n = 67). Data were compared between groups to explore the predictors of IMR improvement after OPCAB.

RESULTS

Seven patients who died before the 1-year postoperative assessment were excluded. At the 1-year follow up, there were 61 patients in the improved group and 67 patients in the failure group. Preoperatively, the improved group had smaller LV global dyssynchrony, LV regional dyssynchrony (papillary muscle systolic dyssynchrony; improved group versus failure group: 48.5 ± 4.5 ms vs 57.1 ± 3.9 ms; P < 0.001) and greater LV ejection fraction (improved group versus failure group: 44.7 ± 5.0% vs 36.7 ± 6.7%; P < 0.001) than the failure group. Papillary muscle systolic dyssynchrony (odds ratio 1.556, 95% confidence interval 1.313-1.845; P < 0.001) and preoperative ejection fraction (odds ratio 0.799, 95% confidence interval 0.691-0.924; P = 0.002) were independent predictors of moderate IMR improvement after OPCAB.

CONCLUSIONS

In the selected patients, preoperative moderate IMR could be relieved by coronary artery bypass grafting. Greater ejection fraction and absence of LV regional dyssynchrony may predict the improvement in moderate IMR after coronary artery bypass grafting, suggesting that LV dyssynchrony especially regional dyssynchrony and preserved ventricular function would be important to the outcome of patients with moderate IMR.

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.

Systolic characteristics and dynamic changes of the mitral valve in different grades of ischemic mitral regurgitation - insights from 3D transesophageal echocardiography

BACKGROUND

Mitral regurgitation in ischemic heart disease (IMR) is a strong predictor of outcome but until now, pathophysiology is not sufficiently understood and treatment is not satisfying. We aimed to systematically evaluate structural and functional mitral valve leaflet and annular characteristics in patients with IMR to determine the differences in geometric and dynamic changes of the MV between significant and mild IMR.

METHODS

Thirty-seven patients with IMR (18 mild (m)MR, 19 significant (moderate+severe) (s)MR) and 33 controls underwent TEE. 3D volumes were analyzed using 3D feature-tracking software.

RESULTS

All IMR patients showed a loss of mitral annular motility and non-planarity, whereas mitral annulus dilation and leaflet enlargement occurred in sMR only. Active-posterior-leaflet-area decreased in early systole in all three groups accompanied by an increase in active-anterior-leaflet-area in early systole in controls and mMR but only in late systole in sMR.

CONCLUSIONS

In addition to a significant enlargement and loss in motility of the MV annulus, patients with significant IMR showed a spatio-temporal alteration of the mitral valve coaptation line due to a delayed increase in active-anterior-leaflet-area. This abnormality is likely to contribute to IMR severity and is worth the evaluation of becoming a parameter for clinical decision-making. Further, addressing the leaflets aiming to increase the active leaflet-area is a promising therapeutic approach for significant IMR. Additional studies with a larger sample size and post-operative assessment are warranted to further validate our findings and help understand the dynamics of the mitral valve.

Mitral valve interventions in heart failure

Secondary mitral regurgitation (MR) results from left ventricular dilatation and dysfunction. Quantification of secondary MR is challenging because of the underlying myocardial disease. Clinical and echocardiographic evaluation requires a multi‐parametric approach. Severe secondary MR occurs in up to one‐fourth of patients with heart failure with reduced ejection fraction, which is associated with a mortality rate of 40% to 50% in 3 years. Percutaneous edge‐to‐edge mitral valve repair (MitraClip) has emerged as an alternative to surgical valve repair to improve symptoms, functional capacity, heart failure hospitalizations, and cardiac haemodynamics. Further new transcatheter strategies addressing MR are evolving. The Carillion, Cardioband, and Mitralign devices were designed to reduce the annulus dilatation, which is a frequent and important determinant of secondary MR. Several transcatheter mitral valve replacement systems (Tendyne, CardiAQ‐Edwards, Neovasc, Tiara, Intrepid, Caisson, HighLife, MValve System, and NCSI NaviGate Mitral) are emerging because valve replacement might be more durable compared with valve repair. In small studies, these interventional therapies demonstrated feasibility and efficiency to reduce MR and to improve heart failure symptoms. However, neither transcatheter nor surgical mitral valve repair or replacement has been proven to impact on the prognosis of heart failure patients with severe MR, which remains high with a mortality rate of 14–20% at 1 year. To date, the primary indication for treatment of secondary severe MR is the amelioration of symptoms, reinforcing the value of a Heart Team discussion. Randomized studies to investigate the treatment effect and long‐term outcome for any transcatheter or surgical mitral valve intervention compared with optimized medical treatment are urgently needed and underway.

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.

Secondary mitral regurgitation (part 2): deliberations on mitral surgery and transcatheter repair

Secondary mitral regurgitation (MR) develops as a consequence of postinfarction remodelling of the ventricle or other causes of left ventricular (LV) dilatation and dysfunction. The presence of MR amplifies the poor prognosis of the failing ventricle, but it has not been established whether the adverse outcomes stem from the MR or whether the MR is simply a marker of progressive LV dysfunction. In this article, an attempt will be made to clarify the clinical impact of mitral surgery and transcatheter repair in patients with secondary MR. Observational studies indicate symptomatic improvement, but the results of randomised trials are mixed. Furthermore, neither mitral surgery nor transcatheter repair consistently leads to reversal of the adverse LV remodelling. There is, however, general agreement that these procedures do not have a salutary effect on survival. Certainly mitral surgery and transcatheter repair can substantially reduce the mitral regurgitant flow, but inconsistencies and uncertainties regarding clinical outcomes persist in the published literature. Some such problems could be resolved by utilisation of more accurate and reproducible imaging modalities in randomised studies of patients who are most likely to benefit from a reduction in the regurgitant volume—namely those with the most severe MR.

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.

Mitral Valve Structure in Addition to Myocardial Viability Determines the Outcome of Functional Mitral Regurgitation After Coronary Artery Bypass Grafting

BACKGROUND

Coronary artery bypass grafting (CABG) reduces functional mitral regurgitation (MR) associated with ischemic heart disease, although the predictive factors or mechanisms of reversibility of functional MR after CABG are not fully understood.We investigated whether mitral valve structure is associated with the outcome of functional MR after CABG.

METHODS AND RESULTS

From a consecutive series of 98 patients with mild-moderate functional MR preoperatively who underwent isolated CABG, we enrolled 66 patients who were followed up for >1 year postoperatively using echocardiography. The degree of MR was reduced in 34 patients (52%) postoperatively, in association with a lower rate of in-hospital treatment for cardiac failure in the long term, compared with the 32 patients (48%) with residual MR postoperatively. The patients with reduced MR postoperatively had longer estimated coaptation length and more anteriorly or centrally directed MR jets than those without reduced MR. On statistical analysis, the addition of estimated coaptation length and jet direction to the reported predictors (ejection fraction, left ventricular end-diastolic dimension, and tenting height) more accurately predicted changes in post-CABG MR than the reported 3 factors alone.

CONCLUSIONS

Residual MR was associated with the emergence of congestive heart failure in the long term after CABG. A specific mitral valve structure, such as large mitral leaflet size or predominant tethering of the posterior leaflet, was a predictive factor for the reversibility of post-CABG functional MR.

2017 ACC Expert Consensus Decision Pathway on the Management of Mitral Regurgitation: A Report of the American College of Cardiology Task Force on Expert Consensus Decision Pathways

Mitral regurgitation (MR) is a complex valve lesion that can pose significant management challenges for the cardiovascular clinician. This Expert Consensus Document emphasizes that recognition of MR should prompt an assessment of its etiology, mechanism, and severity, as well as indications for treatment. A structured approach to evaluation based on clinical findings, precise echocardiographic imaging, and when necessary, adjunctive testing, can help clarify decision making. Treatment goals include timely intervention by an experienced heart team to prevent left ventricular dysfunction, heart failure, reduced quality of life, and premature death.

Ischemic mitral regurgitation

Ischemic mitral regurgitation (IMR) is a frequent complication of left ventricular (LV) global or regional pathological remodeling due to chronic coronary artery disease. It is not a valve disease but represents the valvular consequences of increased tethering forces and reduced closing forces. IMR is defined as mitral regurgitation caused by chronic changes of LV structure and function due to ischemic heart disease and it worsens the prognosis. In this review, we discuss on etiology, pathophysiology, and mechanisms of IMR, its classification, evaluation, and therapeutic corrective methods of IMR.

[Impact of mitral annuloplasty combined with surgical revascularization in ischemic mitral regurgitation]

INTRODUCTION

Ischemic Mitral Regurgitation (IMR) is a serious complication of coronary artery disease and is associated with a poor prognosis. The optimal surgical treatment of IMR involves controversies in its indications and modalities.

OBJECTIVES

To determine whether mitral annuloplasty associated with surgical revascularization improved short and mid terms outcomes compared with revascularization alone in patients with IMR.

METHODS

Between January 2007 and January 2011, 81 patients operated on Department of Cardiovascular Surgery "B" were included in this study divided into 3 groups. Group 1: 28 patients with IMR had mitral valve surgery associated with surgical revascularization. Group 2: 26 patients with IMR had surgical revascularization without mitral valve surgery. Group 3: 27 patients without IMR had isolated revascularization. Clinical end-points were operative mortality, late mortality, postoperative functional status (NYHA), and the Effective Regurgitant Orifice (ERO) at last follow-up. The mean follow-up was 5 years for groups 1 and 2 and 4 years for group 3.

RESULTS

There was no difference between the 3 groups regarding age, sex, cardiovascular risk factors, and extension of coronary artery disease. The Left Ventricle End Diastolic Diameter (LVEDD) and the Left Ventricle Ejection Fraction (LVEF) were slightly different. Late and operative mortality were higher in group 2 compared to groups 1 and 3. Postoperative functional status (NYHA) improved both in groups 1 and 2. In group 1, there was a decrease in ERO.

CONCLUSION

Mitral annuloplasty combined to revascularization improves symptoms, postoperative ERO and short- and mid-term survival compared with revascularization alone.

Exercise Dynamics in Secondary Mitral Regurgitation: Pathophysiology and Therapeutic Implications

Secondary mitral valve regurgitation (MR) remains a challenging problem in the diagnostic workup and treatment of patients with heart failure. Although secondary MR is characteristically dynamic in nature and sensitive to changes in ventricular geometry and loading, current therapy is mainly focused on resting conditions. An exercise-induced increase in secondary MR, however, is associated with impaired exercise capacity and increased mortality. In an era where a multitude of percutaneous solutions are emerging for the treatment of patients with heart failure, it becomes important to address the dynamic component of secondary MR during exercise as well. A critical reappraisal of the underlying disease mechanisms, in particular the dynamic component during exercise, is of timely importance. This review summarizes the pathophysiological mechanisms involved in the dynamic deterioration of secondary MR during exercise, its functional and prognostic impact, and the way current treatment options affect the dynamic lesion and exercise hemodynamics in general.

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.

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.

Timing surgery in mitral regurgitation: defining risk and optimising intervention using stress echocardiography

Mitral regurgitation (MR) is the second most common form of valvular disease requiring surgery. Correct identification of surgical candidates and optimising the timing of surgery are key in management. For primary MR, this relies upon a balance between the peri-operative risks and rates of successful repair in patients undergoing early surgery when asymptomatic with the potential risk of irreversible left ventricular dysfunction if intervention is performed too late. For secondary MR, recognition that this is a highly dynamic condition where MR severity may change is key, although data on outcomes in determining whether concomitant valve intervention is performed with revascularisation has raised questions regarding timing of surgery. There has been substantial interest in the use of stress echocardiography to risk stratify patients in mitral regurgitation. This article reviews the role of stress echocardiography in both primary and secondary mitral regurgitation and discusses how this can help clinicians tackle the challenges of this prevalent condition.