Ischemic mitral regurgitation: intraventricular papillary muscle imbrication without mitral ring during left ventricular restoration

Differentiating Apical and Basal Left Ventricular Aneurysms Using Sphericity Index: A Clinical Study

Background and Objectives: Left ventricular aneurysm (LVA) causes geometric changes, including reduced systolic function and a more spherical shape, which is quantified by the sphericity index (SI), the ratio of the short to long axis in the apical four-chamber view. This study aimed to assess SI's value in A-LVA and B-LVA, identify influencing factors, and evaluate its clinical relevance. Materials and Methods: This clinical study included 54 patients with post-infarction LVA and used echocardiography to determine LVA locations (A-LVA near the apex and B-LVA in the basal segments), with SI and other echocardiographic measures assessed in both systole and diastole for the entire cohort and stratified by A-LVA and B-LVA groups. Results: Among the 54 patients, 41 had A-LVA and 13 had B-LVA. The mean SI was 0.55 in diastole and 0.47 in systole for the cohort. Patients with A-LVA had a mean SI of 0.51 in diastole and 0.44 in systole, while B-LVA patients exhibited significantly higher SI values, with 0.65 in diastole and 0.57 in systole, due to lower long-axis (L) values in both phases. The mean left ventricular ejection fraction (EF) was 23.95% in A-LVA and 30.85% in B-LVA, with no significant difference. However, apical aneurysms were larger (greater LVAV and LVAA) and more significantly reduced functional myocardium. LVEDV, LVESV, LVEDA, and LVESA did not differ significantly between A-LVA and B-LVA. In cases of severe mitral regurgitation (MR), SI was notably higher (0.75 in diastole) due to a marked reduction in the L axis. Conclusions: SI is key in differentiating A-LVA and B-LVA on echocardiography. B-LVA has lower volume and area values, but similar aneurysm and left ventricular volumes and EF. Higher SI in B-LVA is due to a reduced L-axis, and is worsened by severe mitral regurgitation (MR). Surgical ventricular reconstruction (SVR) compensates for L-axis reduction, with preservation of the L axis critical for achieving a more physiological shape. SI thus serves as a marker for left ventricular geometry and surgical outcomes.

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.

Myocardial reconstruction in ischaemic cardiomyopathy

An increase in left ventricular volume after a myocardial infarction is a key component of the adverse remodelling process leading to chamber dysfunction, heart failure and an unfavourable outcome. Hence, the therapeutic strategies have been designed to reverse the remodelling process by medical therapy, devices or surgical strategies. Surgical ventricular reconstruction primarily combined with myocardial revascularization has been introduced as an optional intervention aimed to reduce the left ventricle through resection of the scar tissue and is recommended in selected patients with predominant heart failure symptoms, and with myocardial scarring and moderate left ventricular remodelling. This review outlines the rationale and the technique for reconstructing the left ventricle and the possible indications for using that technique, based on experiences from the centre with the largest international experience. The major contributions in the literature are briefly discussed.

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.

Mitral regurgitation: anatomy is destiny

Mitral regurgitation (MR) occurs when any of the valve and ventricular mitral apparatus components are disturbed. As MR progresses, left ventricular remodelling occurs, ultimately causing heart failure when the enlarging left ventricle (LV) loses its conical shape and becomes globular. Heart failure and lethal ventricular arrhythmias may develop if the left ventricular end-systolic volume index exceeds 55 ml/m2. These adverse changes persist despite satisfactory correction of the annular component of MR. Our goal was to describe this process and summarize evolving interventions that reduce the volume of the left ventricle and rebuild its elliptical shape. This 'valve/ventricle' approach addresses the spherical ventricular culprit and offsets the limits of treating MR by correcting only its annular component.

Application of polymer-mesh device to remodel left ventricular-mitral valve apparatus in ischemic mitral regurgitation

OBJECTIVES

Ischemic mitral regurgitation (IMR) results from ischemic left ventricular (LV) distortion and remodeling, which displaces the papillary muscles and tethers the mitral valve leaflets apically. The aim of this experimental study was to examine efficacy of an adjustable novel polymer filled mesh (poly-mesh) device to reverse LV remodeling and reduce IMR.

METHODS

Acute (N = 8) and chronic (8 weeks; N = 5) sheep models of IMR were studied. IMR was produced by ligation of circumflex branches to create myocardial infarction. An adjustable poly-mesh device was attached to infarcted myocardium in acute and chronic IMR models and compared with untreated sham sheep. Two- and 3-dimensional echocardiography and hemodynamic measurements were performed at baseline, post IMR, and post poly-mesh (humanely killed).

RESULTS

In acute models, moderate IMR developed in all sheep and decreased to trace/mild (vena contracta: 0.50 ± 0.09 cm to 0.26 ± 0.12 cm; P < .01) after poly-mesh. In chronic models, IMR decreased in all sheep after poly-mesh, and this reduction persisted over 8 weeks (vena contracta: 0.42 ± 0.09 cm to 0.08 ± 0.12 cm; P < .01) with significant increase in the slope of end-systolic pressure-volume relationship (1.1 ± 0.5 mm Hg/mL to 2.9 ± 0.7 mm Hg/mL; P < .05). There was a significant reduction in LV volumes from chronic IMR to euthanasia stage with poly-mesh compared with sham group (%end-diastolic volume change -20 ± 11 vs 15% ± 16%, P < .01; %end-systolic volume change -14% ± 19% vs 22% ± 22%, P < .05; poly-mesh vs sham group) consistent with reverse remodeling.

CONCLUSIONS

An adjustable polymer filled mesh device reduces IMR and prevents continued LV remodeling during chronic follow-up.

The role of papillary muscle approximation in mitral valve repair for the treatment of secondary mitral regurgitation

Secondary mitral regurgitation (MR) is present in up to half of patients with dilated cardiomyopathy, and is associated with a poor prognosis. It primarily results from progressive left ventricular remodelling, papillary muscle displacement and tethering of the mitral valve leaflets. Mitral valve repair with an undersized ring annuloplasty is the reparative procedure of choice in the treatment of secondary MR. However, this technique is associated with a 30-60% incidence of recurrent moderate or greater MR at mid-term follow-up, which results in progressive deterioration of left ventricular function and increased morbidity. Combined mitral valve repair and papillary muscle approximation has been applied in order to address both the annular and subvalvular dysfunction that coexist in secondary MR, which include graft and suture-based techniques. Herein, we provide a systematic review of the published literature regarding the technical aspects, clinical application, and outcomes of mitral valve repair with combined ring annuloplasty and papillary muscle approximation for the treatment of secondary MR.

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.

Left ventricular reconstruction: update to left ventricular aneurysm/reshaping techniques

The increase in left ventricular (LV) volume after a myocardial infarction (MI) is a component of the remodelling process and is associated with a poor clinical outcome. Hence, the current management strategy for ischaemic LV dysfunction has been aimed at reversing the remodelling process. Surgical LV reconstruction (LVR) has been introduced as an optional therapeutic strategy aimed at reducing LV volumes through the exclusion of the scar tissue, thereby restoring the physiological volume and shape and improving LV function and clinical status. Until recently, several studies have shown that surgical LVR is effective and relatively safe, with a favourable 5-year outcome. However, in spite of the large amount of reports drawn on various data sets, the additional benefit of LVR to CABG remains debated. We briefly discuss the rationale for surgically reversing LV remodelling through LVR, and, more extensively, the technique and the indications to the best of our knowledge.

Mitral valve repair over five decades

It has become evident that mitral valve (MV) repair is the preferable treatment for the majority of patients presenting with severe mitral regurgitation (MR). This success clearly testifies that the surgical procedure is accessible, reproducible and is carrying excellent long-lasting results. From the pre-extracorporeal circulation's era to the last percutaneous approaches, a large variety of techniques have been proposed to address the different features of MV diseases. This article aimed at reviewing chronologically the development of these dedicated techniques through their origins and the debates that they generated in the literature.

Transventricular mitral valve repair in patients with acute forms of ischemic mitral regurgitation

Transventricular mitral valve surgery combined with left ventricular restoration avoids atriotomy and provides a larger operative field. We describe a series of 5 patients in whom we performed transventricular mitral valve repair by various techniques, such as band annuloplasty, papillary muscle reattachment, chordal cutting, and edge-to-edge repair. The more acute forms of ischemic mitral regurgitation, as found in our patients, can coexist with post-myocardial infarction contained rupture or post-myocardial infarction ventricular septal rupture. Because these patients already have an indication for ventriculotomy, concomitant transventricular repair of the mitral valve can render a separate atriotomy unnecessary and thereby shorten the duration of cardiopulmonary bypass. Moreover, in patients with acute presentations, the absence of atrial dilation (this last associated with chronic cases) might make transventricular repair a better choice than the more difficult atrial approach.

The extent of papillary muscle approximation affects mortality and durability of mitral valve repair for ischemic mitral regurgitation

Background

Since reduction annuloplasty alone for ischemic mitral regurgitation (MR) cannot prevent late recurrence of MR or improve survival for those with left ventricular (LV) dysfunction, and the surgical approach to this etiology is still controversial, we conducted a study to assess the efficacy of the additional papillary muscle approximation (PMA) procedure for ischemic MR by comparing the different subtypes of PMA.

Methods

We studied 45 patients who underwent mitral annuloplasty and papillary muscle approximation (PMA) for ischemic MR between 2003 and 2012. Papillary muscles were approximated entirely (cPMA: complete PMA, n = 32) through an LV incision or partially from the tips to mid-parts (iPMA: incomplete PMA, n = 13) through the mitral and aortic valves. Twenty-three patients with cPMA also underwent LV plasty (LVP). We assessed the outcomes after PMA by comparing cPMA and iPMA.

Results

The baseline MR grade, NYHA class, LV end-diastolic diameter, and LV ejection fraction (LVEF) were 2.8 ± 1.0, 3.2 ± 0.6, 67 ± 6 mm, and 30 ± 10%, respectively. There were no significant differences in these parameters among those with iPMA, cPMA/LVP-, and cPMA/LVP+, though iPMA patients had better LVEF than others. Three patients died before discharge and 12 died during the follow-up. Recurrence of grade 2+ and 3+ MR occurred in 8 and 2 patients, respectively. Reoperation for recurrent MR was performed only for the 2 patients with recurrence of grade 3+ MR. The cPMA was associated with lower mortality (log-rank P = 0.020) and a lower rate of recurrence of MR ≥2+ (log-rank P = 0.005) than iPMA. In contrast, there were no significant differences in the mortality (log-rank P = 0.45) and rate of recurrence (log-rank P = 0.98) between those with cPMA/LVP- and cPMA/LVP+. The 4-year survival rate and rate of freedom from recurrence of MR ≥2+ were 83% and 85% for those with cPMA, repectively. In contrast, the rates were 48% and 48% for those with iPMA, respectively.

Conclusions

Complete PMA could be associated with lower postoperative mortality and higher durability of mitral valve repair for ischemic MR.

Off-pump versus on-pump coronary artery bypass surgery in patients with triple-vessel disease and enlarged ventricles

BACKGROUND AND OBJECTIVES

Off-pump coronary artery bypass grafting (OPCAB) is a popular treatment for patients with ischemic heart disease, especially for high-risk patients. However, whether OPCAB can lead to better clinical outcomes than on-pump coronary artery bypass grafting (ONCAB) in patients with enlarged ventricles remains controversial. This prospective randomized study was designed to characterize comparison of early clinical outcome and mid-term follow-up following ONCAB versus OPCAB in patients with triple-vessel disease and enlarged ventricles.

DESIGN AND SETTINGS

Prospective randomized trial of patients treated at The First Affiliated Hospital, China Medical University, over a 3-year period (2007-2010).

METHODS

A total of 102 patients with triple-vessel disease and enlarged ventricles (end-diastolic dimension >=6.0 cm) were randomized to OPCAB or ONCAB between July 2007 and December 2010. The in-hospital out.comes were analyzed. The study included a mid-term follow-up, with a mean follow-up time of 49.40 (12.88 months).

RESULTS

No significant differences were recorded in the baseline clinical characteristics of ONCAB and OPCAB groups. A statistical difference was found between the two groups at the time of extubation, intensive care unit stay, hospital stay, blood requirements, incidence of intra-aortic balloon pump support, pulmonary complications, stroke, reoperation for bleeding, and inotropic requirements > 24 hours (P < .05). The number of anastomoses performed per patient, the incidence of postoperative ventricular arrhythmia, myocardial infarction, new-onset atrial fibrillation, hemodialysis, infective complications, recurrent angina, and percutaneous reintervention were similar between the 2 groups (P > .05). The left ventricular end-diastolic dimension was significantly smaller at 6 months' follow-up in the 2 groups than it was before operation ( < .05). No differences in hospital mortality and mid-term mortality between OPCAB and ONCAB groups were found. During the follow-up, no patient in either group had undergone repeat coronary artery bypass grafting.

CONCLUSION

No differences in early and mid-term mortality were found between OPCAB and ONCAB in patients with triple-vessel disease and enlarged ventricles. However, OPCAB seems to have a beneficial effect on postoperative complications.

Approximation of papillary muscles for ischaemic mitral regurgitation combined with coronary artery bypass grafting and left ventricular aneurysmectomy: a case report

A 72-year-old female presented with severe ischaemic mitral regurgitation following a recent myocardial infarction. She had no significant past medical history. Pre-operative echocardiogram assessment demonstrated preserved tendinous cords of the mitral leaflets, a mitral valve annulus measuring 3.2 cm with end systolic coaptation of 0.3 cm, impaired left ventricular function with an ejection fraction of 35% and significant ventricular dilatation. Cardiac magnetic resonance imaging (MRI) showed delayed enhancement in the anterolateral, septal and lateral walls and confirmed the impairment of the left ventricle and a large aneurysmal deformation. On-table transoesophageal echo showed that the distance between the two papillary muscles was over 4 cm. We performed coronary artery bypass grafting combined with a Dor Procedure and papillary muscle approximation using a polytetrafluoroethylene (PTFE) vascular graft as a sling, without the insertion of a mitral annuloplasty ring. Postoperative echo and cardiac MRI showed improved left ventricular systolic function and reduced left ventricle volume associated with mild mitral regurgitation. We conclude that papillary muscles approximation as a method of mitral valve repair is a very effective procedure for functional ischaemic mitral regurgitation.

Surgical therapy for heart failure

Today's healthcare delivery system is challenged with an escalating number of heart failure patients who have exhausted medical therapy and overwhelmed the limits of organ transplantation. Scientific and technological advances over the last 20 years have now brought new surgical options to this vast patient population, ranging from ventricular restoration surgery to surgical gene therapy and beyond. This article reviews the myriad of surgical options that are available to these patients, their benefits and shortcomings, as well as potential future directions.

Surgical management of ischemic mitral regurgitation: indications, procedures, and future prospects

Ischemic mitral regurgitation (IMR) is one of the most important risk factors affecting prognosis of patients who suffer from myocardial infarction. The mechanisms of IMR, the indications for surgical intervention, the operative procedures, and the limitations of surgical procedures are discussed in this review article.

LEFT VENTRICULAR REMODELLING AND MITRAL VALVE REMODELLING IN CORONARY HEART DISEASE PATIENTS WITH POST-SURGERY PROGRESSION OF MITRAL REGURGITATION

The progression of ischemic mitral regurgitation (MR) after coronary arty bypass graft (CABG) surgery remains one of the most complex and still unresolved problems in the treatment of coronary heart disease (CHD).

Aim. To study myocardial function, left ventricular (LV) remodelling, and mitral valve (MV) remodelling in CHD patients with MR progression after isolated CABG or CABG combined with LV reconstructive surgery.

Material and methods. In total, 101 CHD patients after CABG were included in the analysis.

Results. The mechanisms of MR progression after isolated CABG differ from those after CABG and LV reconstructive surgery. After the former, LV remodelling progresses both locally and globally, while after the latter, the LV remodelling progression is predominantly global. The patients with post-surgery MR progression differ from their peers without MR in terms of all key parameters of MV geometry.

Conclusion. The leading mechanism of MR progression is local and global LV remodelling, which leads to papillary muscle dislocation and MV leaflet tension and restricted motion. The categories of patients with a high risk of post-surgery MR progression are defined. 

Impact of left ventricular remodelling on outcomes after left ventriculoplasty for ischaemic cardiomyopathy: Japanese surgical ventricular reconstruction group experience

OBJECTIVES

Surgical ventricular reconstruction (SVR) for patients with severe left ventricular (LV) remodelling due to ischaemic cardiomyopathy is still controversial, because the Surgical Treatment for Ischaemic Heart Failure (STICH) trial demonstrated that SVR not only has no beneficial effect on survival compared with coronary artery bypass grafting (CABG) alone, but also is worse for those with a larger LV. Therefore, we assessed the impact of LV remodelling on the outcomes after SVR for ischaemic cardiomyopathy in Japan, using Di Donato's LV shape classification.

METHODS

From 2000 to 2010, 627 patients underwent SVR for ischaemic heart failure in 11 Japanese hospitals. To assess the patients with an LV ejection fraction (LVEF) of ≤ 35% like the STICH trial, considering the severity of LV remodelling, the patients with a preoperative LVEF of >35%, no preoperative LV volume assessment and no preoperative LV shape classification were excluded. Finally, 323 patients were selected as the study subjects. The LV shape was divided into three types according to Di Donato's classification. Types 1 and 3 indicate the aneurysmal and globally akinetic LV, respectively. Type 2 is the intermediate shape.

RESULTS

Type 1, 2 and 3 LV shapes were observed in 85 (26%), 104 (32%) and 134 (42%) of the patients, respectively. The preoperative LV volume and diameter increased if the LV became more akinetic (Type 3 > 2 > 1, P < 0.001). LVEF was lower in those with more akinetic LV (P = 0.002). The preoperative LV end-diastolic volume index and LVEF in Type 3 patients were 133 ± 47 ml/m(2) and 22 ± 7%, respectively. Mitral valve repair was more frequently performed for patients with the Type 3 LV shape (65%) than for the others (P < 0.001). The hospital mortality rates were 2.4, 2.9 and 7.4% for Type 1, 2 and 3 patients, respectively (P = 0.16). Kaplan-Meier analysis demonstrated no significant difference in mortality among the three groups (log-rank P = 0.37). The 5-year survival rates were 81, 70 and 73% for Type 1, 2 and 3 patients, respectively.

CONCLUSIONS

The severity of LV remodelling did not affect survival after SVR plus CABG. The results of SVR were acceptable even for those with globally akinetic LV due to ischaemic cardiomyopathy.

[Mitral regurgitation in heart failure. Surgical therapy]

The optimal treatment of mitral regurgitation concomitant to heart failure remains controversial. A lack of consensus between cardiologists and cardiac surgeons, because of limited studies and heterogeneous data, has led to vaguely defined guidelines and different handling in the clinical routine in the past. However, progress in the operative management with excellent results of individual experienced centers suggests that a variety of patients might benefit from surgical therapy. Each patient should be evaluated individually regarding the benefits of surgical therapy which requires an interdisciplinary approach ("heart team") due to the complex pathophysiology and demanding diagnostics.

Postmyocardial infarction left ventricular dysfunction - assessment and follow up of patients undergoing surgical ventricular restoration by the endoventricular patchplasty

BACKGROUND

Surgical ventricular restoration with endoventricular patchplasty improves left ventricular function and restores left ventricular shape.

METHOD

The study included patients who presented with transmural anterior myocardial infarctions between June 2007 and May 2008. Briefly the technique included - coronary revascularization, resection of the endocardial scar, left ventricular reconstruction using an endoventricular synthetic patch. Left ventricular geometric parameters were studied preoperatively, early postoperatively, at 3 and 6 months and statistically analyzed by SPSS 14 software package.

RESULTS

The ejection fraction increased from 33.5 ± 5.02 to 37.77 ± 7.17 immediate postoperatively. The preoperative left ventricular ejection fraction - a mean of 33.25% (±5.02%), increased by 10.3%-11% at the third and fourth follow up respectively after surgical ventricular restoration (p ≤ 0.001). The left ventricular end systolic volume index improved from a mean of 48.84 ± 11.37 preoperatively to 24.66 ± 5.92 postoperatively (p ≤ 0.001).

CONCLUSIONS

Surgical ventricular restoration in our study has clearly demonstrated a positive effect on LV geometry.

Surgical approaches to mitral regurgitation

Surgical approaches to correct mitral regurgitation (MR) have evolved over 50 years and form much of the basis for percutaneous approaches to the mitral valve. Surgical mitral repairs have been more durable with use of annuloplasty, but recurrent regurgitation not resulting in reoperation can occur. The mitral leaflets may be resected or augmented, with recent trends to preserve leaflet coaptation surfaces if possible. Mitral chords tend to be replaced or transferred instead of being shortened. Mitral replacement still has a role when more durable and reliable than repair. Surgical incisions have varied from full sternotomy down to percutaneous access only, with less invasiveness usually requiring a trade-off versus effectiveness or ease of application. Less invasive options in treating MR may encourage higher-risk patients to seek anatomic therapy, whether surgical or percutaneous. Rapidly evolving technology will continue to be a dominant driver of surgical approaches to MR, with increasing overlap and interaction with percutaneous approaches.

Surgical treatment of functional mitral regurgitation

Incidence of functional mitral regurgitation (FMR) is increasing due to aging and better survival after acute myocardial infarction, the most frequent cause of FMR. At the basis of FMR there is a displacement of one of both papillary muscle(s) and/or annular enlargement, which can be primitive or, more often, secondary. There is general agreement that its natural history is unfavorable, as witnessed by a considerable body of evidences. However, even if there is no clear evidence that surgical treatment of FMR changes consistently the outcome of patients with this disease, at least in terms of survival, there are some studies which show that function improves, as well as the global quality of life. The guidelines reflect this uncertainty, providing no clear indications, even in the gradation of severity of the FMR. Surgical techniques are variable and are mainly addressed to the annulus (restrictive annuloplasty), which is only a part of the anatomic problem related to FMR. Insertion of a prosthesis inside the native valve is appearing more and more a valuable option rather than a bail out procedure. On the other side, techniques addressed to modify the position of the papillary muscles appear to be still under investigation and not yet in the armamentarium of surgical treatment of FMR. Even after many years, rules are not established and results are fluctuating, but how and when to treat FMR is becoming more and more a topic of interest in cardiac surgery.

Transventricular edge-to-edge repair of the mitral valve during surgical ventricular restoration: review of the literature

BACKGROUND

Mitral valve surgery for functional ischemic mitral regurgitation (MR) in high-risk patients, including those requiring multiple concomitant cardiac operations, carries a significant risk of morbidity and mortality. In patients undergoing surgical ventricular restoration, transventricular edge-to-edge repair provides an effective alternative to conventional mitral valve surgery. We report such a case.

METHODS

A 67-year-old male with ischemic cardiomyopathy and severe left ventricular dysfunction presented to our institution with a 3-month history of dyspnea on exertion, angina, and leg edema. He was found to have triple-vessel coronary artery disease, a severely dilated left ventricle with an apical aneurysm, and moderate-to-severe MR (3+). In addition to coronary artery bypass graft surgery, an edge-to-edge mitral valve repair was undertaken via a longitudinal ventriculotomy performed for concomitant surgical ventricular restoration.

RESULTS

Total cardiopulmonary bypass and aortic cross-clamp times were 101 minutes and 86 minutes, respectively. Postoperative transesophageal echocardiography revealed no MR, and the patient was discharged home on postoperative day 9. A follow-up transthoracic echocardiogram revealed trace MR on postoperative day 15. At 11 months postoperative, the patient remains in New York Heart Association functional class I.

CONCLUSION

Transventricular edge-to-edge repair of the mitral valve in patients with ischemic cardiomyopathy and functional MR undergoing SVR is a safe and effective alternative to conventional valve surgery, and should be considered in this high-risk population.

Optimal surgical management of severe ischemic mitral regurgitation: to repair or to replace?

BACKGROUND

Ischemic mitral regurgitation, a complication of myocardial infarction and coronary artery disease more generally, is associated with a high mortality rate and is estimated to affect 2.8 million Americans. With 1-year mortality rates as high as 40%, recent practice guidelines of professional societies recommend repair or replacement, but there remains a lack of conclusive evidence supporting either intervention. The choice between therapeutic options is characterized by the trade-off between reduced operative morbidity and mortality with repair versus a better long-term correction of mitral insufficiency with replacement. The long-term benefits of repair versus replacement remain unknown, which has led to significant variation in surgical practice.

METHODS AND RESULTS

This article describes the design of a prospective randomized clinical trial to evaluate the safety and effectiveness of mitral valve repair and replacement in patients with severe ischemic mitral regurgitation. This trial is being conducted as part of the Cardiothoracic Surgical Trials Network. This article addresses challenges in selecting a feasible primary end point, characterizing the target population (including the degree of mitral regurgitation) and analytical challenges in this high mortality disease.

CONCLUSIONS

The article concludes by discussing the importance of information on functional status, survival, neurocognition, quality of life, and cardiac physiology in therapeutic decision making.

Papillary muscle sandwich plasty for the treatment of functional mitral valve regurgitation

We evaluated the availability of original "sandwich plasty" for the treatment of functional mitral regurgitation (FMR) associated with ischemic heart disease (IHD) and aortic valve disease (AVD). Forty-three patients were reviewed, including 27 IHD patients and 16 AVD patients. Preoperatively severe FMR was detected in 14 patients, moderate FMR in 26, and mild FMR in 3. The papillary muscle heads of anterior leaflets and posterior leaflets were approximated using Teflon-pledgeted 3-0 Ticron sutures at anterolateral and posteromedial commissural portions. After surgery, residual moderate FMR was observed in 1 patient and mild FMR in 3 patients. Tenting height of the mitral valve significantly decreased. FMR free rates 2 years after surgery were 93% among IHD patients and 83% in AVD patients. "Sandwich plasty" was simple and effective for the treatment of functional FMR caused by tethering effects due to left ventricular dilatation.

Surgical ventricular restoration to reverse left ventricular remodeling

Heart failure is one of the major health care issues in the Western world. An increasing number of patients are affected, leading to a high rate of hospitalization and high costs. Even with administration of the best available medical treatment, mortality remains high. The increase in left ventricular volume after a myocardial infarction is a component of the remodeling process. Surgical Ventricular Restoration (SVR) has been introduced as an optional therapeutic strategy to reduce left ventricular volume and restore heart geometry. So far, it has been established that SVR improves cardiac function, clinical status, and survival in patients with ischemic, dilated cardiomyopathy and heart failure. Since its first description , SVR has been refined in an effort to standardize the procedure and to optimize the results. This review will discuss the rationale behind surgical reversal of LV remodeling, the SVR technique, its impact on cardiac function and survival, and future expectations.

Mitral regurgitation after anteroapical myocardial infarction: new mechanistic insights

BACKGROUND

Mitral regurgitation (MR) generally accompanies inferobasal myocardial infarction (MI), with leaflet tethering by displaced papillary muscles. Mitral regurgitation is also reported with anteroapical MI without global dilatation or inferior wall motion abnormalities. We hypothesized that anteroapical MI extending to the inferior apex displaces the papillary muscles, tethering the mitral leaflets to cause MR.

METHODS AND RESULTS

In the retrospective part of the study, consecutive anteroapical MI patients were studied. Moderate-severe MR occurred in 9% of 234 patients with only anteroapical MI versus 17% of 242 with inferoapical extension (P<0.001). Ejection fraction was only mildly different (41 ± 4% versus 46 ± 5%; P<0.01). In the human mechanistic portion of the study, 60 anteroapical MI patients (20 with only 2 apical segments involved and 40 with involvement of all 4 apical segments; 20 with MR and 20 without MR) were compared with 20 normal controls. Those with MR (≥ moderate) had higher systolic papillary muscle-to-annulus tethering length (P < 0.01). Mitral regurgitation grade correlated most strongly with tethering length (r = 0.70) and its diminished systolic shortening (r = -0.65). In the animal study, 9 sheep with left anterior descending coronary artery ligation were analyzed. Four sheep that developed MR had inferoapical MI extension with tethering length increasing over 1.5 months (2.1 ± 0.4 to 2.9 ± 0.4 cm, P < 0.001) versus no significant increase in 5 sheep without MR (2.0 ± 0.4 to 2.1 ± 0.3 cm, P not statistically significant). In MR sheep, the normal decrease in tethering length from diastole to systole was eliminated (P < 0.01).

CONCLUSIONS

Anteroapical MI with inferoapical extension can mechanically displace papillary muscles, causing MR despite the absence of basal and midinferior wall motion abnormalities. This suggests the possibility of repositioning treatments for this condition.

Surgical options of ischemic mitral regurgitation

Mitral regurgitation after a myocardial infarction is common. It can occur acutely or chronically, and its presence portends a poor prognosis. The focus of this article will be on chronic ischemic mitral regurgitation. We will discuss the current concepts of its pathophysiology, the benefits of revascularization, along with the surgical, and percutaneous therapeutic options.

Assessment of changes in mitral valve configuration with multidetector computed tomography: impact of papillary muscle imbrication and ring annuloplasty

BACKGROUND

The optimal surgical procedures in functional mitral regurgitation remain controversial. We applied papillary muscle imbrication (PMI) combined with undersized mitral annuloplasty (UMAP). Multidetector computed tomography (MDCT) provides images of different phases of the cardiac cycle, allowing an assessment of the geometry. In the present study, we evaluated the mitral valve configuration and subvalvular apparatus before and after UMAP and/or PMI using MDCT imaging.

METHODS AND RESULTS

We studied 26 patients with functional mitral regurgitation (3+ to 4+) with an ejection fraction ≥35% who underwent diagnostic MDCT examinations before and early after the operation. Of these, 15 underwent UMAP and PMI (UMAP+PMI group) and 11 underwent UMAP (UMAP group). The annular anteroposterior diameter, tenting height, tenting area, and interpapillary muscle distance at end-systole were quantified. The annular anteroposterior diameter, tenting height, and tenting area were significantly decreased after the operation in both groups. Whereas the average change in annular anteroposterior diameter, tenting area, and interpapillary muscle distance did not differ between the 2 groups, the average change in tenting height was greater in the UMAP+PMI group than in the UMAP group (5.1±1.3 versus 3.8±2.3 mm, P=0.036). There was a significant correlation between the change in interpapillary muscle distance and the change in tenting height in the UMAP+PMI group (r=0.788, P=0.0005).

CONCLUSIONS

Our results examined with MDCT indicated that UMAP combined with PMI improved leaflet tethering compared with UMAP, reflecting differences in the effects of the surgical procedures used, and suggested that concomitant PMI might be beneficial in some cases.

Papillary muscle head approximation for the treatment of mitral valve regurgitation combined with aortic valve disease

We initiated an original papillary muscle head approximation procedure, commonly known as Sandwich plasty, for the treatment of ischemic mitral regurgitation (MR). In this study, we evaluated the appropriateness of this procedure for functional MR associated with aortic valve disease. Fifteen patients who had undergone Sandwich plasty combined with aortic valve surgery were included in this study. The mean age of the patients was 69 years. Predominant aortic valve diseases were regurgitation in 8 patients and stenosis in 7 patients. Aortic valve replacement was performed in 14 patients and David surgery in one. The mitral valve was approached through the aortic annulus in 9 patients (the transaortic group). Six other patients with mitral valve annulus of 30 mm or larger underwent concomitant mitral ring-annuloplasty through a left atrial incision (the LA group). The tenting height of the mitral valve and left ventricle diastolic diameter significantly decreased after surgery in both groups. After surgery, residual moderate or mild MR was detected in two patients in the transaortic group. In the LA group, residual mitral regurgitation was not detected. In the follow-up study, prominent MR occurred in two patients in the transaortic group. The MR free rate two years after surgery was 83% in the total patient population. Sandwich plasty was simple and effective in the treatment of functional mitral regurgitation combined with aortic valve surgery. A transaortic approach is effective in obviating a separate left atriotomy and reducing operation time.

A new surgical ventricular restoration technique to reset residual myocardium's fiber orientation: the "KISS" procedure

BACKGROUND

The history of surgical reconstruction of the left ventricle after an anterior myocardial infarction shows an evolution of techniques which tend to a more and more physiologic restoration of ventricular shape and volume, with increasing attention to the orientation of myocardial fibers.

METHODS

We set a new surgical procedure for endoventricular patch reconstruction technique with the aim to rebuild a physiologic shape and volume of the left ventricle caring about realignment of myocardial fibers orientation. Peculiarities of this reconstruction are the shape of the patch (reduction of minor axis compared with currently used oval-shaped patch) and the asymmetrical way of suturing it inside the ventricle.

RESULTS

We present a detailed description of operative steps of this procedure, and we add some relevant surgical hints to clarify its peculiarities. Most of the patients operated on with this technique showed the original renewal of apical rotation and left ventricular torsion as specific index of the restoration of physiologic fiber orientation: we report an exemplary case of at-sight recovery of apical rotation in the operating room.

CONCLUSION

This technique can represent a reproducible new way to realign myocardial fibers in a near-normal setting, improving the physiological restoration of ischemically injured left ventricle. It could be also the basis to reconsider surgical treatment for heart failure.

Surgical treatment for heart failure: left ventricular restoration for cardiomyopathy

Congestive heart failure has become a major problem and the only surgical treatment for end-stage heart failure caused by dilated cardiomyopathy (DCM) had been heart transplantation. However, because of the shortage of donors, several procedures for non-transplant surgery have been developed. Published literature on left ventricular (LV) restoration was searched to review the new surgical procedures for treating patients with ischemic or non-ischemic DCM. LV restoration was initiated in the 1980s for repairing LV aneurysm. In the 1990s several surgical procedures were introduced for treating DCM, and the new evolving surgical treatment plays an important role in the management of DCM in the 21st century.

Original papillary muscle sandwich plasty for ischemic mitral regurgitation

BACKGROUND

Mitral valve plasty for functional ischemic mitral regurgitation (MR) is still a controversial procedure.

METHODS AND RESULTS

The present study was a review of 23 patients who underwent an original technique known as "papillary muscle sandwich plasty" in which the mitral valve is approached via either the left atrium or left ventricle. The heads of the papillary muscles of the anterior leaflet and leaflets are plicated using Teflon-pledgeted 3-0 Ticron sutures in both the anterolateral and posteromedial commissural portions. Postoperative residual mild MR occurred in 1 patient (4%), but moderate or severe MR was not observed. In the follow-up study, prominent MR occurred in 1 patients and the MR-free rate at 2 years after surgery was 93%. Late cardiac death was significantly (P<0.05) fewer in patients without prominent MR than that in patients with MR.

CONCLUSIONS

"Sandwich plasty" is an effective technique for patients requiring left ventricular plasty and may improve the prognosis of ischemic heart failure.

Papillary muscle approximation for ischemic mitral valve regurgitation

In patients with ischemic left ventricular dysfunction and functional mitral regurgitation, the surgical treatment of the mitral insufficiency remains a challenging issue. Several procedures were described to restore a more normal alignment between the mitral annulus and the laterally displaced papillary muscles. We report a new approach to relocate the displaced papillary toward the mitral annulus and to reduce tethering. This procedure is believed to be technically easy and beneficial in terms of mitral repair.