The importance of grade 2 ischemic mitral regurgitation in coronary artery bypass grafting

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.

Outcome of Surgery for Ischemic Mitral Regurgitation Depends on the Type and Timing of the Coronary Revascularization

OBJECTIVE

Long-term outcomes of mitral valve (MV) repair versus MV replacement for ischemic mitral regurgitation (IMR) in patients undergoing either prior (PCR) or concomitant coronary revascularization (CCR) by surgery (CABG) or intervention (PCI) are uncertain.

METHODS AND RESULTS

Of 446 patients receiving MV surgery for IMR between July 2006 and December 2010, 125 patients-87 CCR (69.1%) and 38 PCR (30.9%)-were eligible for inclusion in the study. Survival was higher in CCR versus PCR at long-term follow-up (78.83% vs. 57.9%, p = 0.016). The incidence of MACCE was lower in the CCR compared to PCR at both hospital discharge (34.11% vs. 63.57%, p = 0.003) and at follow-up (34.11% vs. 65.79%, p = 0.0008). Patients receiving CABG or CABG with PCI in PCR had higher mortality risks after MV surgery than CCR patients (X2 = 6.029, p = 0.014 and X2 = 6.466, p = 0.011, respectively). Whereas in the PCR group, MV repair and MV replacement achieved similar survival probability (X2 = 1.551, p = 0.213), MV repair in the CCR group led to improved survival compared to MV replacement (X2 = 3.921, p = 0.048). In MV replacement, LAD-CABG improved survival compared to LAD-PCI (U = 15,000.00, Z = -2.373 p = 0.018), and a substantial impact of arterial IMA-LAD grafting was revealed in the Cox-regression analysis (HR 0.334, CI: 0.113-0.989, p = 0.048) as opposed to venous-LAD grafting (HR 0.588, CI: 0.166-2.078, p = 0.410).

CONCLUSION

Early treatment of IMR concomitant to coronary revascularization enhances long-term survival compared to delayed MV surgery after PCR. MV repair is not superior to MV replacement when performed late after coronary revascularization; however, MV repair leads to better survival than MV replacement when performed concomitantly with CABG with arterial LAD revascularization.

Analysis of changes in "mitral valve reserve" after coronary artery bypass grafts in patients with functional mitral regurgitation

INTRODUCTION

The treatment of moderate functionalmitral regurgitation (FMR) during coronary artery bypass grafting (CABG) is still debated. Our primary end point was to assess the improvement of "mitral valve reserve" (MVR) after CABG alone as a clinical demonstration of left ventricular (LV) recovery.

MATERIALS AND METHODS

Between June 2019 and June 2021, we prospectively enrolled 104 consecutive patients undergoing CABG with moderate FMR. Inclusion criteria were inferior-posterior-lateral wall hypokinesia and revascularization of the circumflex or right coronary artery. MVR was calculated as the ratio between anterior and posterior leaflets' straight length. All patients were followed for 1 year. The improvement of MVR has been considered as a reduction of the ratio between anterior and posterior leaflets straight length.

RESULTS

Compared to baseline, mean MVR was significantly reduced both at 6 (2.24 ± 0.95 vs. 1,91 ± 0.6; p = 0,047) and 12 months follow-up (2.24 ± 0.95 vs. 1,69 ± 0.49; p = 0,006). Left ventricular (LV) reverse remodeling, meant as improvement of LV ejection fraction and reduction of LV end-systolic volume index and mitral anulus diameter were evaluated at 6 months and 1 year. Mitral regurgitation grade were also significantly reduced at 6 months (p < .001).

CONCLUSION

The benefits of myocardial revascularization in term of improvement of mitral regurgitation's degree can be explained by the changes of MVR. The patients with FMR, who could have more advantages from CABG alone, should be the ones who have LVESVi just moderately increased.

Isolated OPCABG in moderate chronic ischemic mitral regurgitation: is it a justifiable alternative approach ?

OBJECTIVE

Current evidence does not allow a consensus on the management of moderate chronic ischemic mitral regurgitation (CIMR). We compared moderate CIMR patients undergoing off-pump CABG (OPCABG) alone and CABG + MV repair for early mortality, major adverse systemic events (MASE) and mid-term functional outcomes.

METHODS

210 patients with moderate CIMR who underwent off-pump coronary artery bypass grafting (OPCABG) Group I (n = 106) or CABG + mitral valve repair (MV rep) Group II (n = 104) were followed prospectively. For comparison, patients were further sub-divided based on the product of regurgitant fraction and ejection fraction "RFEF"(Good/Bad) and MR jet direction (Central/Eccentric). The primary end point of the study was mortality and secondary end points were MASE, percentage improvements in indexed left ventricle end-systolic volume (LVESVI %), MR grade and functional outcomes of the patients.

RESULTS

In-hospital and overall mortality was significantly lower in Group I (1.89% vs. 13.46%, p < 0.001 and 5.66% vs. 15.38%; p = 0.024 respectively). Group II had significantly higher MASE, ventilation time, mean ICU and hospital stay. At 36 months, LVESVI% (17.56% ± 9.12% vs. 18.81% ± 7.48%; p = 0.279), MR grade improvement (80.18% vs. 83.50%; p = 0.544), NYHA class and MLHF scores were also similar in both groups. On subgroup analysis, Good RFEF with Central jet subgroup had comparable improvement in LVESVI% and MR grade with either procedure, while Bad Eccentric subgroup showed a significantly higher improvement in LVESVI% and MR grade with CABG + MV repair.

CONCLUSION

OPCABG is associated with significantly reduced mortality and MASE with comparable improvement in LVEDVI% and MR grade. CABG + MV Rep results in significant improvement in LVEDVI% and MR grade in patients with bad eccentric MR. The recommended procedures in the "Good Central" and "Bad Eccentric" subsets are CABG and CABG + Mvrepair, respectively.

Stress Echocardiography Protocol for Deciding Type of Surgery in Ischemic Mitral Regurgitation: Predictors of Mitral Regurgitation Recurrence following CABG Alone

PURPOSE

Although coronary artery bypass grafting alone (CABGa), or, with mitral annuloplasty (CABGmp), is considered the best therapeutic strategy for patients with ischemic mitral regurgitation (IMR), some recurrences are still reported. The aim of this study was to evaluate the use of the mitral deformation indices (MDI) as a predictor of recurrence of mitral regurgitation in a 12-month follow-up after CABG alone.

METHODS

A total of 145 patients after myocardial infarction with significant IMR, eligible for CABG, were prospectively enrolled in the study. Mitral valve morphology, left ventricle function, IMR degree as assessed by effective regurgitation orifice area (ERO), myocardial viability, and MDI were assessed prior to surgery. Patients were referred for CABGa (gr.1; n = 90) or CABGmp (gr.2; n = 55) based on clinical assessment, and the results of rest and stress echocardiography (exercise echocardiography and low dose dobutamine echocardiography-DBX). One year after surgery, each patient underwent the evaluation of cardiovascular events. Univariable logistic regression analysis was used to identify the factors of recurrence of IMR in 1 year follow-up. Serial echo examinations were performed in all patients at discharge, and at 1 and 12 months after surgery.

RESULTS

Logistic regression analysis revealed that in CABGa, group preoperative changes of tenting area (TA) and coaptation high (CH) during DBX remained the predictors of the recurrence of IMR in 12 months follow-up. TAdbx > 1 cm2 provided a sensitivity of 90% and specificity of 29%, (AUC 0.6436). The best cut-off value for CHdbx was 0.4 cm (sensitivity 90%, specificity 34%; AUC 0.6432). In both groups (CABGa vs. CABGmp) no significant differences were observed in 12-month mortality (1.2% vs. 0%; p = 1.0), hospitalizations due to the heart failure (HF) exacerbation (5.9% vs. 8.5%; p = 0.72), and in the incidence of the composite endpoint (deaths/CV hosp/stroke) (7% vs. 8.5%; p = 0.742).

CONCLUSIONS

The preoperative assessment of MDI changes during dbx can be used to identify patients with IMR qualified to CABG alone at increased risk of recurrence of IMR in 1 year follow-up. Mitral deformation analysis should be used for a better qualification of patients with IMR to the exact surgical approach.

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.

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.

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.

"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.

Repair or replace for severe ischemic mitral regurgitation: prospective randomized multicenter data

Ischemic mitral regurgitation (IMR) is a subset of functional mitral regurgitation (MR) that has the potential to impact an increasing number of patients in the future. This is in the context of a worldwide population, which continues to live longer with improved survival after myocardial infarction. Substantial data have accumulated over the past few decades demonstrating the negative effects of IMR. Further, significant research has been done to define the optimal surgical approach and several studies have compared mitral repair versus replacement for patients with severe mitral regurgitation (SMR). Studies supporting performance of mitral repair cite superior operative morbidity and mortality rates, while proponents of mitral replacement cite improved long-term durability and correction of MR. Lack of clinically robust Level I randomized controlled trial data have curtailed attempts to better define appropriate surgical treatment allocation over the past few decades. Recently, however, the Cardiothoracic Surgical Trials Network (CTSN) conducted the first randomized controlled trial, funded by the National Heart, Lung, and Blood Institute, the National Institute for Neurological Diseases and Stroke and the Canadian Institute for Health Research, to compare the performance of mitral repair versus replacement for SMR. Herein, the present review describes the design, results and implications of the CTSN SMR trial and its efforts to identify the most efficacious surgical approach to SMR. This review also describes CTSN investigation to predict the recurrence of MR after mitral repair.

Mitral valve repair versus replacement

Degenerative, ischemic, rheumatic and infectious (endocarditis) processes are responsible for mitral valve disease in adults. Mitral valve repair has been widely regarded as the optimal surgical procedure to treat mitral valve dysfunction of all etiologies. The supporting evidence for repair over replacement is strongest in degenerative mitral regurgitation. The aim of the present review is to summarize the data in each category of mitral insufficiency and to provide recommendations based upon this data.

Surgical treatment of moderate ischemic mitral regurgitation

BACKGROUND

Ischemic mitral regurgitation is associated with increased mortality and morbidity. For surgical patients with moderate regurgitation, the benefits of adding mitral-valve repair to coronary-artery bypass grafting (CABG) are uncertain.

METHODS

We randomly assigned 301 patients with moderate ischemic mitral regurgitation to CABG alone or CABG plus mitral-valve repair (combined procedure). The primary end point was the left ventricular end-systolic volume index (LVESVI), a measure of left ventricular remodeling, at 1 year. This end point was assessed with the use of a Wilcoxon rank-sum test in which deaths were categorized as the lowest LVESVI rank.

RESULTS

At 1 year, the mean LVESVI among surviving patients was 46.1±22.4 ml per square meter of body-surface area in the CABG-alone group and 49.6±31.5 ml per square meter in the combined-procedure group (mean change from baseline, -9.4 and -9.3 ml per square meter, respectively). The rate of death was 6.7% in the combined-procedure group and 7.3% in the CABG-alone group (hazard ratio with mitral-valve repair, 0.90; 95% confidence interval, 0.38 to 2.12; P=0.81). The rank-based assessment of LVESVI at 1 year (incorporating deaths) showed no significant between-group difference (z score, 0.50; P=0.61). The addition of mitral-valve repair was associated with a longer bypass time (P<0.001), a longer hospital stay after surgery (P=0.002), and more neurologic events (P=0.03). Moderate or severe mitral regurgitation was less common in the combined-procedure group than in the CABG-alone group (11.2% vs. 31.0%, P<0.001). There were no significant between-group differences in major adverse cardiac or cerebrovascular events, deaths, readmissions, functional status, or quality of life at 1 year.

CONCLUSIONS

In patients with moderate ischemic mitral regurgitation, the addition of mitral-valve repair to CABG did not result in a higher degree of left ventricular reverse remodeling. Mitral-valve repair was associated with a reduced prevalence of moderate or severe mitral regurgitation but an increased number of untoward events. Thus, at 1 year, this trial did not show a clinically meaningful advantage of adding mitral-valve repair to CABG. Longer-term follow-up may determine whether the lower prevalence of mitral regurgitation translates into a net clinical benefit. (Funded by the National Institutes of Health and the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00806988.).

Surgical Strategy for Moderate Ischemic Mitral Valve Regurgitation: Repair or Ignore?

<p><strong>Background:</strong> Ischemic heart disease is a significant complication of atherosclerosis. Myocardial infarction after the development of coronary artery disease can lead to a number of serious complications, including ischemic mitral regurgitation (IMR). Currently there is no consensus regarding the preferred therapeutic modality for moderately severe IMR. In this study, the postoperative outcome of concomitant coronary artery bypass (CABG) and mitral valve repair was compared with that of CABG alone in two groups of patients with moderately severe IMR.</p><p><strong>Methods:</strong> A total of 84 patients who underwent operations for coronary artery disease and moderately severe IMR were included in the study. Preoperative demographic and clinical characteristics were recorded at the time of admission. The severity of mitral regurgitation was graded using transthoracic echocardiography and left ventriculography.</p><p><strong>Results:</strong> Significant postoperative improvements were observed in ejection fraction and systolic diameter compared to preoperative values (<em>P</em> = .006 and <em>P</em> = .020 respectively, in the intervention group, <em>P</em> = .001 and <em>P</em> = .001 respectively, in the control group). The decrease in pulmonary artery pressure (PAP) was significant only in the intervention group (<em>P</em> = .001). There was a significantly marked reduction in the severity of IMR in the intervention group compared to control.</p><p><strong>Conclusion:</strong> Surgical repair of the mitral valve in conjunction with CABG for moderately severe IMR appears to be more effective than isolated CABG for certain outcome parameters, including decreased severity of mitral regurgitation and decreased pulmonary artery pressure.</p>

Ischemic mitral regurgitation: pathophysiology, diagnosis and surgical treatment

Ischemic mitral valve regurgitation often complicates acute myocardial infarction and also represents a negative prognostic factor for long-term survival in patients undergoing surgical myocardial revascularization. While severe mitral regurgitation should always be corrected during a coronary artery bypass operation, the decision making is more difficult in patients with a mild-to-moderate degree of regurgitation. Recent studies and experimental protocols have elucidated the pathophysiological mechanisms leading to mitral regurgitation with great interest in annular modifications and subvalvular alterations. These data suggest that new and integrated surgical approaches that address annuloplasty ring sizing, ring type selection and tethering phenomenon (i.e., chordal cutting, 'edge-to-edge' technique and left-ventricular plasty techniques) are required for a safer and durable valve repair. Transthoracic and transesophageal echocardiography are useful in determining the etiology and the degree of mitral regurgitation, to assess mitral deformation and to measure indexes of global and regional left-ventricular remodeling. Stress echocardiography may unmask higher degrees of mitral regurgitation. More data are needed in order to confirm the promising and interesting preliminary experimental findings of magnetic resonance imaging in diagnosis and clinical evaluation of ischemic mitral regurgitation.

Ischemic mitral regurgitation: not only a bystander

Ischemic mitral regurgitation (MR) is a common complication of left ventricular (LV) dysfunction related to chronic coronary artery disease. This complex multifactorial disease involves global and regional LV remodeling, as well as dysfunction and distortion of the components of the mitral valve including the chordae, the annulus, and the leaflets. Its occurrence is associated with a poor prognosis. The suboptimal results obtained with the most commonly used surgical strategy, involving mitral valve annuloplasty with coronary bypass grafting, emphasize the need to develop alternative surgical techniques targeting the causal mechanisms of the disease. A comprehensive preoperative assessment of mitral valve configuration and LV geometry and function and an accurate quantification of MR severity at rest and during exercise may contribute to improve risk stratification and to tailor the surgical strategy according to the individual characteristics of the patient.

Impact of coronary artery bypass surgery on ischemic mitral regurgitation

INTRODUCTION

To determine the course of ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG), and evaluate preoperative factors which predict the development of the severity of IMR after CABG.

METHODS

Between 1992-2005, 1995 patients underwent CABG and 170 of them had IMR. Data of 131 patients were retrospectively analyzed and living patients (n = 112) had a clinical follow-up visit. The mean follow-up time was 6.5 years.

RESULTS

At the time of CABG, 66% of the 131 cases analyzed had mild, 31% had moderate, and 3% had severe IMR. At the time of follow-up, 52% of patients had either no IMR or mild IMR, 27% had moderate IMR, 6% had severe IMR and 15% suffered from cardiac related death. During follow-up IMR grade reduced in 25% of study patients. None of the patient had re-operation due to the mitral regurgitation. Multivariate analysis showed that left ventricular ejection fraction (LVEF) was an independent predictor of good prognosis (O.R. 1.4, 95% C.I. 1.15-1.83/ 10% increase of LVEF, p = 0.02).

CONCLUSION

Half of the patients, who have IMR at the time of CABG, have no IMR or only mild IMR postoperatively. Good LVEF adds to the probability that CABG only can reduce IMR.

Should all ischemic mitral regurgitation be repaired? When should we replace?

PURPOSE OF REVIEW

Ischemic mitral regurgitation (IMR) is a major source of morbidity and mortality. Although mitral valve repair has become recently popularized for the treatment of IMR, select patients may derive benefits from replacement. The purpose of this review is to describe current surgical options for IMR and to discuss when mitral valve replacement (MVR) may be favored over mitral valve repair.

RECENT FINDINGS

Current surgical options for the treatment of IMR include surgical revascularization alone, mitral valve repair, or MVR. Although surgical revascularization alone may benefit patients with mild-moderate IMR, most surgeons advocate the performance of revascularization in combination with either mitral valve repair or replacement. In the current era, mitral valve repair has proven to offer improved short-term and long-term survival, decreased valve-related morbidity, and improved left ventricular function compared with MVR. However, MVR should be considered for high-risk patients and those with specific underlying mechanisms of IMR.

SUMMARY

In the absence of level one evidence, mitral valve repair offers an effective and durable surgical approach to the treatment of mitral insufficiency and remains the operation of choice for IMR. MVR, however, is preferred for select patients. Future randomized, prospective clinical trials are needed to directly compare these surgical techniques.

Predictors of improvement of unrepaired moderate ischemic mitral regurgitation in patients undergoing elective isolated coronary artery bypass graft surgery

BACKGROUND

The persistence of moderate ischemic mitral regurgitation (IMR) after isolated coronary artery bypass graft surgery is an important independent predictor of long-term mortality. The aim of the present study was to identify predictors of postoperative improvement in moderate IMR in patients with ischemic heart disease undergoing elective isolated coronary artery bypass graft surgery.

METHODS AND RESULTS

The study population consisted of 135 patients with ischemic heart disease (age, 65+/-9 years; 81% male) and moderate IMR undergoing isolated coronary artery bypass graft surgery. Fourteen patients died before the 12-month follow-up echocardiography and were excluded. At the 12-month follow-up, 57 patients showed no or mild IMR (improvement group), whereas 64 patients failed to improve (failure group). Before coronary artery bypass graft surgery, the improvement group had significantly more viable myocardium and less dyssynchrony between papillary muscles than the failure group (P<0.001). All other preoperative parameters were similar in both groups. Large extent (> or =5 segments) of viable myocardium (odds ratio, 1.45; 95% confidence interval, 1.22 to 1.89; P<0.001) and absence (<60 ms) of dyssynchrony (odds ratio, 1.49; 95% confidence interval, 1.29 to 1.72; P<0.001) were independently associated with improvement in IMR. The majority (93%) of patients with viable myocardium and an absence of dyssynchrony showed an improvement in IMR. In contrast, only 34% and 18% of patients with dyssynchrony and nonviable myocardium, respectively, showed an improvement in IMR, whereas 32% and 49%, respectively, of these patients showed worsening of IMR (P<0.001).

CONCLUSIONS

Reliable improvement in moderate IMR by isolated coronary artery bypass graft surgery was observed only in patients with concomitant presence of viable myocardium and absence of dyssynchrony between papillary muscles.

POINT: Efficacy of adding mitral valve restrictive annuloplasty to coronary artery bypass grafting in patients with moderate ischemic mitral valve regurgitation: a randomized trial

OBJECTIVE

Surgical management of moderate chronic ischemic mitral valve regurgitation is still debated. The aim of this study was to evaluate the effect of adding mitral valve repair to coronary artery bypass grafting on clinical outcomes and left ventricular remodeling in patients who underwent coronary artery bypass grafting alone versus coronary artery bypass grafting plus mitral valve repair in a randomized trial.

METHODS

Between February 2003 and May 2007, 102 patients were eligible for this study and were randomly assigned to one of 2 groups by means of card allocation: coronary artery bypass grafting plus mitral valve repair (CABG plus MVR group; 48 patients, 47%) or coronary artery bypass grafting alone (CABG group; 54 patients, 53%). The 2 groups were similar regarding demographics, perioperative clinical data, and outcomes. There were differences regarding cardiopulmonary bypass (P < .0001) and aortic crossclamp (P < .0001) times. Exercise tests were performed for all survivors to evaluate tolerance to exercise and variability on grade of mitral regurgitation and systolic pulmonary arterial pressure. The study was blinded for physicians and nurses involved in postoperative care and clinical follow-up. The mean follow-up was 32 +/- 18 months.

RESULTS

Overall in-hospital mortality was 3% (3 patients). One (1.8%) patient died in the CABG group, and 2 (4.1%) patients died in the CABG plus MVR group. Survival rates +/- standard error at 5 years for patients in the CABG and CABG plus MVR groups were 88.8% +/- 3.2% and 93.7% +/- 3.1%, respectively. A significant difference was found between the 2 groups with regard to mean New York Heart Association class (P < .0001), left ventricular end-diastolic diameter (P < .01), left ventricular end-systolic diameter (P < .01), pulmonary arterial pressure (P < .0001), and left atrial size (P < .01). At follow-up, coronary artery bypass grafting alone was able to reduce mitral regurgitation grade in 40% of patients, whereas in the remaining patients mitral regurgitation grade remained stable or worsened. In the CABG group, among the 17 patients with mild mitral regurgitation and 12 patients with moderate mitral regurgitation at rest, 7 (40%) and 9 (75%) patients, respectively, had worsening in mitral regurgitation grade and pulmonary artery pressure during exercise.

CONCLUSIONS

The efficacy of adding mitral valve repair to coronary artery bypass grafting is well demonstrated by the improvement of New York Heart Association functional class and percentage of left ventricular ejection fraction and by the decrease of mitral regurgitation grade, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, pulmonary artery pressure, and left atrial size. Moreover, coronary artery bypass grafting alone left more patients with heart failure symptoms at rest and during exercise. Combined coronary artery bypass grafting and mitral valve repair have no effect on survival at short-term follow-up, and the trends that are evident will likely become more significant with time.

Left ventricular remodeling following ischemic mitral valve repair: predictive factors

OBJECTIVES

Annuloplasty is the most common surgical procedure for ischemic mitral regurgitation (MR) that improves symptoms but is also subjected to high incidence of recurrent MR. One of the reasons of recurrent MR could be further left ventricular (LV) remodeling.

DESIGN

The study population consisted of 195 patients with ischemic MR. Mitral valve repair and bypass surgery was performed between 2000 and 2006.

RESULTS

LV end diastolic diameter (LVEDD) increased in 30.3% of patients in one year following mitral repair. Multivariate ANOVA analysis revealed that if LVEDD index (LVEDDi) before surgery is less than 25 mm/m(2), the probability for LVEDDi to diminish or to stay at the same range is 84.6% higher, than in the case of preoperative LVEDDi >or=25 mm/m(2) and other predictive variables.

CONCLUSIONS

Predictive factors for further LV remodeling after ischemic mitral repair 1 year after surgery are preoperative LVEDDi, preoperative LV end systolic diameter index, tricuspid regurgitation grade before surgery, and early postoperative MR grade.

Elastic Properties of the Ascending Aorta and Left Ventricular Function in Patients with Hypothyroidism

BACKGROUND

We sought to clarify the possible role of elastic properties of the ascending aorta in the development of cardiac disease associated with hypothyroidism (HT).

METHODS

A total of 37 patients with HT (age: 39.3 +/- 8.9 years) and 29 control subjects were studied. Ascending Aortic (Ao) diameter, Ao elastic indexes, strain (AoST), distensibility (AoD), stiffness index (AoSI), and pressure strain modulus were calculated from the echocardiographically derived Ao diameters. Myocardial performance index (MPI), E/A ratio, isovolumetric relaxation time (IVRT), deceleration time (DT) were measured by Doppler echocardiography to assess diastolic LV function. Patients were treated with levothyroxine and followed-up for 6 months. Thyroid function tests and echocardiographic measurements were repeated at the end of the study.

RESULTS

AoD (cm2 dyn(-1) 10(-3)) and AoST (%) were significantly lower (3.8 vs. 6.1; P < 0.001, 7.4 vs. 12.6, P < 0.001; respectively), whereas AoSI was higher in HT patients (6.2 vs. 3.3; P < 0.001). After treatment, AoD and AoST were increased (5.7; P < 0.001 and 11.8; P < 0.001; respectively), whereas AoSI was decreased significantly (3.7; P < 0.001). Also, early/late mitral peak velocity ratio (Emax/Amax) was significantly lower in HT patients (1.19 vs 1.34; P < 0.01), whereas MPI was higher (0.52 vs. 0.42; P < 0.001). MPI showed a strong correlation with aortic root indexes [AoST (r =-0.61/P < 0.001); AoD, (r =-0.57/P < 0.002); AoSI, (r = 0.53/P < 0.005)] in the HT group. After 6 months of therapy, MPI significantly decreased P < 0.001) and E/A ratios were normalized (P < 0.001).

CONCLUSIONS

Ao root functions have an important role on diastolic LV function. Levothyroxine replacement therapy can reverse all of these adverse effects of HT.

Is ischemic mitral regurgitation an indication for surgical repair or replacement?

Ischemic mitral regurgitation (IMR) is common in patients with coronary artery disease. While it is well-known that IMR exerts a graded effect upon survival-the greater the degree of IMR, the lower the survival-the indications for surgical treatment and the choice of surgical procedure (repair versus replacement) are controversial. In patients with mild to moderate IMR, the benefit of a mitral valve procedure has not been demonstrated, and surgical practice varies. In patients with severe IMR, mitral valve surgery is the norm, but guidelines for choosing between valve repair and valve replacement do not exist. Furthermore, the survival impact of mitral valve surgery in patients with severe IMR is uncertain. When patients with severe IMR undergo mitral valve surgery, undersized annuloplasty results in durable repair in 70% to 85% of cases. Newly-developed adjunctive repair techniques may further improve results. Currently, mitral valve repair is the procedure of choice in the majority of patients having surgery for severe IMR. However, the most severely ill patients and those with certain echocardiographic characteristics (e.g. severe bileaflet tethering) should be treated with bioprosthetic mitral valve replacement rather than repair.

Impact of Moderate Functional Mitral Insufficiency in Patients Undergoing Surgical Revascularization

BACKGROUND

Mild and moderate functional ischemic mitral insufficiency present at the time of surgical revascularization present clinical uncertainty. It is unclear whether the relatively poor outcomes in this cohort are dependent on valvular function or related to left ventricular dysfunction. The purpose of this study was to examine the early and late outcomes in patients with less-than-severe functional ischemic mitral insufficiency at the time of isolated coronary artery bypass grafting (CABG).

METHODS AND RESULTS

From 1996 through 2004, 2242 consecutive patients undergoing isolated CABG were identified as having none to moderate mitral regurgitation (MR) and no valve leaflet pathology. All of the patients at this single institution routinely had an intraoperative transesophageal echocardiography, prospectively quantified MR, and ejection fraction (EF). The New York State Cardiac Surgery Reporting System infrastructure was used to prospectively collect in-hospital patient variables and outcomes. Social Security Death Benefit Index was used to determine long-term survival. Odds ratio and significance (P value) are presented for each determined risk factor. There were 841 patients (37.5%) with no MR, 1137 (50.7%) with mild MR, and 264 (11.8%) with moderate MR. The patients with moderate MR were more likely to be older, female, and have more renal disease, previous MI, congestive heart failure, previous cardiac surgery, and lower EFs. Hospital mortality was independently and significantly associated with renal disease, decreasing EF, increasing age, previous cardiac operation, and cerebral vascular disease. Multivariable analysis revealed decreased survival with increasing age, previous operation, congestive heart failure, diabetes, nonelective operation, decreasing EF, and the presence of moderate MR (expbeta = 1.49; P=0.007) and mild MR (expbeta = 1.34; P=0.033).

CONCLUSIONS

Independent of ventricular function, mild and moderate functional mitral insufficiency are associated with significantly decreased survival in patients undergoing CABG. Whether correction of moderate functional MR at the time of CABG improves outcome still needs to be determined.

External reshaping of the left ventricle in off-pump surgery

BACKGROUND

: Dyskinetic areas of the lateral and inferior left ventricular (LV) wall are frequently encountered in patients with coronary artery disease. In clinical practice, all of the techniques described for the restoration of shape and function of the LV require cardiopulmonary bypass. A new technique of LV external reshaping that aims to obtain a near-normal ventricular conical shape is described. This technique is performed during an off-pump coronary artery bypass graft (CABG) operation. It is used mainly on the inferior and lateral walls of the ventricle, but also on the anterolateral wall when warranted. This technique can be considered an alternative to classic aneurysmectomy in high-risk cases.

METHODS

: All patients underwent total arterial revascularization without aortic manipulation. Intraoperative transesophageal echocardiography was used in all cases to define the dilated akinetic/dyskinetic area. This area was effectively plicated using interrupted mattress sutures reinforced with Teflon felt or pericardial strips. This technique allows near normalization of the geometry of the ventricle and LV end-diastolic volume reduction. In cases of preexisting mitral regurgitation (MR), a reduction of the MR was observed after lateral wall restoration. From September 2002 to April 2005, the external reshaping technique was applied on 56 cases among 949 off-pump CABG cases (5.9%). A detailed transthoracic echocardiogram was obtained preoperatively. The mean ejection fraction of all enrolled patients was 31.2 ± 7%. The location of the plication was: lateral wall in 22, inferior wall in 16, and anterolateral wall in 18. The average number of coronary anastomoses was 2.6. Twelve patients were found to have 2-3+ MR. All patients were followed up during a period of 35 months.

RESULTS

: One patient died due to severe right ventricular dysfunction. Seven patients developed atrial fibrillation, and one had ventricular tachycardia. During the follow-up period, we observed a reduction of left ventricular end-diastolic diameter and a parallel augmentation of ejection fraction (mean 42.2 ± 4%). The ventricular cavity's architecture was normalized. Among the 12 patients with MR, an improvement of regurgitation was noted in 10 (from 2-3+ to 1-2+). One patient died during the follow-up period, and 1 patient required reoperation due to persistent severe MR.

CONCLUSIONS

: The external reshaping of the LV during beating heart surgery is technically feasible, has promising results, and can be performed without major complications.

Low-dose dobutamine stress echocardiography to predict reversibility of mitral regurgitation with CABG

The optimal management of moderate (grade 2-3+) ischemic mitral regurgitation (MR) in patients undergoing coronary artery bypass grafting (CABG) remains controversial. While CABG alone can reverse regurgitation in some patients with moderate MR, adjunctive mitral repair may be necessary in others. We performed low-dose dobutamine stress echocardiography (DSE) in 60 patients with moderate MR who were about to undergo CABG. Group I, 25 patients who demonstrated reduction in MR during DSE, had CABG alone. Group II, 35 patients in whom MR was unchanged during DSE, had mitral valve repair as well as CABG. MR was reduced postoperatively in both groups (P < 0.0001). Postoperative ejection fraction in Group I (12.2%) improved more than that in Group II (9.3%) (P < 0.01). We conclude that CABG alone may be sufficient to correct moderate MR when MR is reduced during DSE.

Impact of No-to-Moderate Mitral Regurgitation on Late Results After Isolated Coronary Artery Bypass Grafting in Patients With Ischemic Cardiomyopathy

BACKGROUND

This study analyzes retrospectively a cohort of patients with ischemic cardiomyopathy (ejection fraction < or = 0.30) who underwent isolated coronary artery bypass grafting to evaluate the impact of no-to-moderate mitral regurgitation (MR) on long-term results.

METHODS

From January 1988 to December 2002, 6,108 patients had isolated coronary artery bypass grafting. Two hundred thirty-nine (3.9%) had ischemic cardiomyopathy; 60 patients had no, 102 had mild, and 77 had moderate MR. Using propensity score, a group of 70 patients with no or mild MR (group A) was case-matched with a group of 70 patients with moderate MR (group B) to obtain two groups with similar preoperative characteristics.

RESULTS

Nine patients (6.4%) died within the first 30 days; all deaths were cardiac-related. There was no difference in the early results between groups. Patients in group B showed lower freedom from death, from cardiac death, from cardiac death and ischemic events, and from death and New York Heart Association class III and IV than patients in group A. Cox analysis confirmed that moderate MR was an independent variable for worse late outcome in this subgroup of patients. Functional and echocardiographic results, after a mean of 62 +/- 28 months in 87.8% of survivors, showed a significant impairment of New York Heart Association class (from 2.2 +/- 0.5 to 2.8 +/- 0.6; p < 0.001) and MR degree (from 2.0 to 2.7 +/- 1.0; p = 0.023) in patients with preoperative moderate MR.

CONCLUSIONS

This study confirms that moderate ischemic MR has an important negative impact on survival and quality of life of patients with severely impaired left ventricular function, treated by coronary artery bypass grafting alone.

Late outcomes after isolated coronary artery bypass grafting for ischemic mitral regurgitation

OBJECTIVES

Although ischemic mitral regurgitation (IMR) is one of the most important issues to determine therapeutic strategy for ischemic heart disease, long-term outcome after coronary artery bypass grafting (CABG) for IMR is still unclear. It is also controversial how patients who would benefit from mitral valve (MV) surgery in combination with CABG should be identified. The purpose of this study is to elucidate late outcomes after isolated CABG for moderate IMR and to assess the indication of combined MV surgery.

METHODS

Two hundred and seventy-nine patients who had grade 2 or 3 IMR preoperatively and underwent isolated CABG between 1980 and 2002 in our institute were enrolled. Mitral regurgitation was assessed by 2-dimensional Doppler echocardiography and left ventriculography. Among them, 84 patients (30.1%) had left ventricular ejection fraction (LVEF) less than 30% and 186 patients (66.7%) had prior inferior myocardial infarction (MI).

RESULTS

One hundred and twenty-nine patients (46.2%) remained grade 2 or greater MR early postoperatively. Actuarial survival and freedom from cardiac events, analyzed by the Kaplan-Meier method, were 90.9% and 87.7% at 1 year, 79.2% and 68.8% at 5 years, 54.9% and 49.1% at 10 years and 48.8% and 18.9% at 15 years. Independent predictive risk factors for cardiac events, analyzed by multivariate analysis using the Cox proportional hazard model, were grade 2 or greater MR which remained early postoperatively (p = 0.0002), LVEF < 30% preoperatively (p = 0.0006), no inferior MI preoperatively (p = 0.007) and no internal thoracic artery-left anterior descending artery graft (p = 0.049). More than a 15% decrease in LVEF at more than 3 years after the operation was seen despite patent bypass grafts in 17.2% of patients who received a late follow-up catheterization, although 41.4% of patients showed an increase or less than 5% decrease in LVEF during this period.

CONCLUSION

Combined MV surgery with CABG for IMR should be considered in patients with poor LVEF or without prior inferior MI.

Long-Term Survival After Surgical Revascularization for Moderate Ischemic Mitral Regurgitation

BACKGROUND

We sought to characterize patient survival and degree of late mitral regurgitation (MR) in patients undergoing surgical revascularization with moderate ischemic MR.

METHODS

We retrospectively reviewed 251 patients undergoing coronary artery bypass graft (CABG) surgery between 1991 and 2001 with 3+ ischemic MR, including 31 patients who had concomitant mitral annuloplasty. Univariate and multivariable testing was employed.

RESULTS

Actuarial 1-, 5-, and 10-year survival was 84.0%, 67.5%, and 37.1% in the overall group of 251 patients. Independent predictors of long-term mortality were age 70 years or more (hazard ratio 2.50 [95% confidence interval 1.82 to 3.44]), prior myocardial infarction (3.99 [2.15 to 7.39]), unstable angina (2.27 [1.69 to 3.04]), chronic renal failure (4.87 [3.13 to 7.58]), atrial fibrillation (2.21 [1.65 to 2.96]), left internal mammary artery to left anterior descending artery graft (0.28 [0.18 to 0.43]), preoperative beta-blocker (0.43 [0.28 to 0.67]), ejection fraction (0.71/10% [0.64 to 0.80]), left atrium size (0.88/mm [0.84 to 0.92]), diffuse wall motion abnormalities (2.83 [1.77 to 4.55]), and mitral leaflet restriction (3.85 [2.46 to 5.99]). The model controlled for the performance of annuloplasty, which did not emerge as an independent predictor. Patients undergoing annuloplasty did have less mean late MR than those having CABG alone (p = 0.005). Overall, 57.8% of patients (63 of 109) with follow-up echocardiograms had improvement in grade of MR compared with baseline. In 54 of 95 patients (56.8%), intraoperative transesophageal echocardiography downgraded the degree of MR compared with the preoperative study.

CONCLUSIONS

Patients with moderate ischemic MR undergoing CABG had relatively poor long-term survival, with significant differences when stratified according to preoperative characteristics. Performance of mitral annuloplasty reduced the degree of regurgitation but was not a predictor of long-term survival. Intraoperative transesophageal echocardiography frequently downgraded the degree of MR.

Initial Report of Off-Pump Coronary Artery Bypass Surgery as Sole Therapy for Moderate Ischemic Mitral Regurgitation: Operative and Intermediate-Term Outcome

Background: Patients undergoing on-pump coronary artery bypass surgery (CAB) with coexistent moderate ischemic mitral regurgitation (IMR) have a significant mortality rate compared to patients without MR. The mortality rate is elevated both perioperatively (0%-12% mortality), as well as over a 1- and 2-year postoperative period (15%-25%). It is thought that some patients are best served by off-pump CAB (OPCAB); however, outcomes have not been reported for such patients with coexistent moderate IMR. Methods: We reviewed the independent database of patients undergoing OPCAB between 1995 and 2002 to find 989 patients, 17 (1.7%) of whom had moderate or moderately severe MR. Patients were contacted and clinical and echocardiographic data were obtained. Results: The patient group consisted of 11 men and 6 women (age, 65 15 years). The study group had a PA pressure of 52 14, creatinine of 1.6 0.7, and left ventricular ejection fraction of 43 18. Nine patients (53%) had advanced New York Heart Association (class III-IV) heart failure. Mortality rates perioperatively and at 1, 2, and 3 years were 0%, 6.25% (1/16), 12.5% (2/16), and 38% (4/8), respectively. At the time of this report, no patient had returned for a reparative procedure. Conclusion: In patients felt to be best served by OPCAB with ischemic MR, operative and intermediate mortality rates are remarkably similar to those previously reported for on-pump series. These data underscore the continued need to understand which patients undergoing CAB require mitral valve problems to be addressed at the time of surgery.

Importance of Moderate Ischemic Mitral Regurgitation

BACKGROUND

The importance of moderate ischemic mitral regurgitation in patients presenting for coronary artery bypass grafting (CABG) is controversial. Therefore, we tracked the course of unrepaired moderate ischemic mitral regurgitation after CABG surgery alone, identified factors associated with worsening postoperative ischemic mitral regurgitation, and assessed the impact of unrepaired moderate ischemic mitral regurgitation on survival.

METHODS

From 1980 to 2000, 467 patients with moderate ischemic mitral regurgitation underwent CABG alone. The course of unrepaired mitral regurgitation was estimated by a longitudinal analysis of 267 follow-up echocardiograms from 156 patients. The survival impact of moderate ischemic mitral regurgitation was determined among propensity-matched patients with and without ischemic mitral regurgitation.

RESULTS

Mitral regurgitation was dynamic early postoperatively. Immediately postoperatively, it was absent or mild in 73% and severe in 6%; by 6 weeks, these figures were 40% and 22%, respectively. The course of postoperative mitral regurgitation was not associated with the preoperative extent of coronary artery disease or left ventricular dysfunction. Five-year survival of matched bypass patients without ischemic mitral regurgitation was 85% compared with 73% for patients with moderate ischemic mitral regurgitation (p = 0.003).

CONCLUSIONS

Moderate ischemic mitral regurgitation does not reliably resolve with CABG surgery alone and is associated with reduced survival. Therefore, a mitral valve procedure may be warranted for such patients presenting for CABG. A randomized trial comparing strategies of revascularization with mitral valve repair and revascularization alone is required to determine optimal treatment.

Mitral valve repair in ischemic mitral regurgitation

Ischemic mitral regurgitation (IMR) is a common complication after acute myocardial infarction due to annulus dilatation and papillary muscles displacement. In our opinion 3/4 and 4/4 IMR have always to be indicated for MV surgery. In presence of low EF and dilated LV, moderate (2/4) IMR has to be corrected. The end-systolic distance between the coaptation point of mitral leaflets and the plane of mitral valve annulus is the key point to decide repair (≦10 mm) or replacement (≫10 mm). MV annuloplasty has always been addressed to the posterior annulus, whose size can be easily reduced. A specially designed 40 mm long ring has been used to achieve a posterior overreductive annuloplasty. For MV repair thirty-day mortality was 2.4%. Five-year survival and the possibility of being alive and in NYHA class I-II were 75.6±4.7 and 59.8±5.4, respectively. After a mean of 38±35 months, the NYHA class decreases from 3.2±0.5 to 2.1±0.6 (P≪0.001). Most patients (77.4%) have an improvement of its own functional class. MR decreases from 3.2±0.8 to 1.2±1.1 (P≪0.001). 97.5% of the survivors have MR equal to or less than moderate.

Evolution of Redo Cardiac Surgery:. Review of Personal Experience

This presentation summarizes the author's personal observations on the major advances in reoperative cardiac surgery. They include earlier referral for cardiac prosthetic and bioprosthetic cardiac valve dysfunction, alternative incisional approaches to minimize injury to adherent cardiac structures, alternative perfusion sites, improved hemostasis on cardiopulmonary bypass, improved myocardial protection, tailoring the valve prosthesis to the patients' anatomy and clinical situation, "no-touch" technique in reoperative coronary artery surgery, and increasing use of hypothermic circulatory arrest for recurrent ascending arch and descending thoracic pathology. Each of these is explained in detail with the appropriate references and retrospective data collections where appropriate. This risk of reoperative cardiac surgery will continue to improve as these and additional techniques continue to evolve and become simplified. Further investigation into the clinical uses of minimally invasive techniques including robot technology, may eventually reduce morbidity and mortality of reoperations to that equal to primary operations.

Mitral valve surgery for chronic ischemic mitral regurgitation

BACKGROUND

Early and midterm clinical and echocardiographic results after mitral valve (MV) surgery for chronic ischemic mitral regurgitation were investigated to evaluate the validity of the criteria for repair or replacement applied by us.

METHODS

From 1988 to 2002, 102 patients with ischemic mitral regurgitation underwent MV surgery (82 repairs and 20 replacements). End-systolic distance between the coaptation point of mitral leaflets and the plane of mitral annulus was the key factor that allowed either repair (<or=10 mm) or replacement (>10 mm). Patients who had MV replacement showed higher New York Heart Association class (3.2 +/- 0.5 versus 3.4 +/- 0.5; p = 0.016), lower preoperative ejection fraction (0.33 +/- 0.9 versus 0.38 +/- 0.12; p = 0.034), and higher end-diastolic volume (161 +/- 69 mL versus 109 +/- 35 mL; p < 0.001) compared with repair. Mitral regurgitation was 3.2 +/- 0.7 in both groups.

RESULTS

Thirty-day mortality was 3.9% (2.4% MV repair versus 10.0% MV replacement; not significant). During the follow-up 26 patients died. Of the 72 survivors, 55 (76.3%) were in New York Heart Association classes I and II. Five-year survival was 75.6% +/- 4.7% in MV repair and 66.0% +/- 10.5% in MV replacement (not significant). Survival in New York Heart Association classes I and II was 58.9% +/- 5.4% in MV repair and 40.0% +/- 11.0% in MV replacement (not significant). Cox analysis identified preoperative New York Heart Association class, ejection fraction, end-diastolic volume, end-systolic volume, and congestive heart failure as risk factors common to both events. In 46 patients, late echocardiograms showed no volume or ejection fraction modifications. In patients who underwent MV repair, 50% had no or mild mitral regurgitation.

CONCLUSIONS

Correction of chronic ischemic mitral regurgitation through either repair or replacement provides a good 5-year survival rate, with more than 75% of the survivors in New York Heart Association classes I and II.

Mild to moderate mitral regurgitation in patients undergoing coronary bypass grafting: effects on operative mortality and long-term significance

BACKGROUND

Patients undergoing bypass grafting (CABG) often present with mitral regurgitation (MR). While surgical strategy for patients with either trace or severe MR is well established, the need for a valve procedure with mild (2) to moderate (3+) mitral regurgitation is controversial.

METHODS

We reviewed 1,939 consecutive CABG patients (1987 to 1999). A preoperative echocardiogram performed when clinically indicated graded MR from 1 to 4+. Patient characteristics, hospital mortality, and long-term survival were compared between 167 patients with grade 2 to 3+ MR and controls. A multivariate analysis identified independent predictors for long-term mortality.

RESULTS

The MR patients were more often female and older; had increased comorbidities including hypertension, diabetes, and heart failure; had more extensive coronary disease and worse left ventricular (LV) function; and required urgent surgery more often. Operative mortality was 0.8% in no MR patients and 1.8% in MR patients (p not significant). Long-term survival for MR patients with poor LV function (LV grade 3 to 4) was significantly lower (53% versus 75% at 10 years, p = 0.001). Independent predictors of poor long-term survival were advanced age, LV dysfunction, heart failure, diabetes, prior cerebrovascular accident, peripheral vascular disease, and no left internal mammary artery use.

CONCLUSIONS

Coronary artery bypass graft patients with mild or moderate MR have worse baseline characteristics but operative mortality with CABG alone is not significantly increased. Long-term prognosis for MR patients with poor LV function is worse compared with patients with no MR but MR was not an independent predictor of long-term mortality. To determine whether surgical correction of MR would improve results, a prospective randomized trial seems warranted.

Survival after coronary revascularization, with and without mitral valve surgery, in patients with ischemic mitral regurgitation

BACKGROUND

The most appropriate treatment for patients with ischemic mitral regurgitation (IMR) is often debated. We compared the survival rates of patients with IMR undergoing different treatment strategies, namely: medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), and CABG + mitral valve (MV) surgery.

METHODS AND RESULTS

Patients undergoing catheterization between 1986 and 2001 were included. IMR was defined as: >or=grade 2+ mitral regurgitation (MR) and significant coronary artery disease (CAD) without primary mitral valve disease. Patients undergoing catheterization for the evaluation of congenital or other valvular heart disease were excluded. Multivariable Cox proportional hazards modeling was utilized to assess the independent relation between treatment and survival. Propensity score methods were used to correct for the nonrandom assignment of treatment. Of the 2,757 patients who met study criteria: 1,305 were treated medically, 537 underwent PCI, 687 underwent CABG, and 228 underwent CABG + MV surgery. The median duration of follow-up was 3.2 (0.9, 7.1) years. Patients undergoing CABG + MV surgery had more severe MR and more severe heart failure than those treated by other modalities. After adjusting for differences in baseline characteristics, patients undergoing PCI, CABG, and CABG + MV surgery had a 31% (hazards ratio [HR]=0.69; P=0.0001), 42% (HR=0.58; P=0.0001), and 42% (HR=0.58; P=0.0001) reduction in the risk of death, respectively, compared with those undergoing medical therapy. The performance of mitral valve surgery with CABG was not associated with improved survival versus CABG alone (P=0.258).

CONCLUSIONS

Among patients with IMR, treatment with PCI, CABG, or CABG + MV surgery is associated with improved survival compared with medical therapy.

Echocardiographic assessment of anatomic lesions predicts surgical strategy in mitral regurgitation

OBJECTIVE

In the present study, we evaluate our ability to predict surgical procedure repair or replacement using preoperative echocardiography.

DESIGN

The reports from transthoracic echocardiographic examinations of 298 patients were analyzed and the gross anatomic lesions and the mechanisms involved were classified into one of three main groups (functional with normal valves, organic degenerated with hypermobile valve or organic degenerated without hypermobility).

RESULTS

It was possible to assess the likelihood of repair in 226 patients (76%). The criteria used were institution based and reflect the surgical procedures during the study period (1995-1999). The proportion of patients undergoing repair was 58%. In patients with a high likelihood, repair was performed in 86%. The corresponding figures in the intermediate- and low-likelihood groups were 63 and 23%, respectively. Hypermobility in the posterior leaflet and functional mitral regurgitation led to repair in the majority of patients, while patients with hypermobility in the anterior or both valves more frequently underwent replacement.

CONCLUSION

We conclude that it is possible to identify patients with a high likelihood of repair using transthoracic echocardiography.

Trends in the surgical management of ischemic mitral regurgitation

The surgical approach to ischemic mitral regurgitation (IMR) remains a topic of considerable controversy. Will coronary artery bypass alone suffice, or should the valve be intervened upon? The poor late survival of patients with IMR is well recognized, but it remains unknown if this can be altered by addressing the valve directly. And if surgery is undertaken, should the valve be repaired or replaced? The underlying mechanisms of IMR remain incompletely understood, and although current theory focuses on the role of alterations in ventricular geometry in its pathogenesis, IMR is most often addressed by annuloplasty alone. Is this sufficient, or does the ventricle itself require "remodeling?" The debate is confounded by imprecise terminology that fails to distinguish between acute and chronic disease, and active ischemia from completed infarction. Available clinical information is from retrospective studies with all of their inherent limitations and potential for bias. Still, progress is being made as increasing attention is focused on this clinically important entity.

Can late survival of patients with moderate ischemic mitral regurgitation be impacted by intervention on the valve?

BACKGROUND

Ischemic mitral regurgitation is known to be associated with poor long-term outcome after coronary artery bypass grafting; however, our ability to alter that outcome with intervention on the valve is unclear. The decision to address the valve is most challenging for patients with only moderate mitral regurgitation, particularly with the popularization of off-pump surgery. We therefore reviewed early and late outcomes of patients undergoing revascularization with or without mitral valve surgery.

METHODS

Patients with moderate mitral regurgitation undergoing revascularization with and without mitral surgery between January 1991 and September 1996 were identified retrospectively. Operative notes were reviewed and patients with structural valve disease excluded. Perioperative events and late outcomes as determined by telephone contact and search of the social security death index (survival data 97% complete) were compared.

RESULTS

One hundred seventy-six patients with moderate mitral regurgitation underwent revascularization alone (n = 142) or with mitral repair or replacement (n = 34). Those undergoing revascularization alone had a higher serum creatinine, somewhat less mitral regurgitation, and lower New York Heart Association functional class preoperatively. Operative mortality was greater with valve surgery (21% vs 9%, p = 0.047). Actuarial survival of both groups at 5 years was similar (52% vs 58%, p = NS); however, when stratified by preoperative functional class, those with more advanced heart failure preoperatively had superior late survival if their mitral valve was intervened upon.

CONCLUSIONS

The late survival of patients with ischemic mitral regurgitation undergoing coronary revascularization remains poor; however, intervention on the mitral valve appears to benefit those with symptomatic heart failure.