Annular or subvalvular approach to chronic ischemic mitral regurgitation?

OBJECTIVE: We sought to investigate whether annular or subvalvular interventions corrected chronic ischemic mitral regurgitation differently. METHODS: Sheep underwent placement of markers on the left ventricle, mitral annulus, papillary muscles (anterior and posterior), and both leaflet edges. A transannular suture (septal-lateral annular cinching) was anchored to the midseptal mitral annulus and externalized through the midlateral mitral annulus. Another suture (papillary muscle repositioning) from the posterior papillary muscle was passed through the mitral annulus near the posterior commissure and externalized. After 7 days, 3-dimensional marker data were obtained before inducing posterolateral myocardial infarction. After 7 weeks, animals in whom chronic ischemic mitral regurgitation developed (n = 10) were restudied before and after pulling septal-lateral annular cinching or papillary muscle repositioning sutures. End-systolic septal-lateral annular diameter and 3-dimensional displacement of the papillary muscles and leaflet edges were computed. RESULTS: Infarction increased mitral regurgitation (0.6 +/- 0.5 to 2.3 +/- 1.1); mitral annular septal-lateral dilation (4 +/- 1 mm); posterior papillary muscle displacement laterally (4 +/- 2 mm), posteriorly (9 +/- 3 mm), and toward the annulus (2 +/- 1 mm); posterior mitral leaflet apical tethering (3 +/- 1 mm); and interleaflet separation (+3 +/- 1 mm, P < .05 baseline vs chronic ischemic mitral regurgitation). Septal-lateral annular cinching reduced septal-lateral dimension (-9 +/- 3 mm), corrected lateral posterior papillary muscle displacement (4 +/- 1 mm) and septal-lateral interleaflet separation (-4 +/- 2 mm), and decreased mitral regurgitation (0.6 +/- 0.6, P < .05 septal-lateral annular cinching vs chronic ischemic mitral regurgitation) without affecting posterior leaflet restriction. Papillary muscle repositioning reduced septal-lateral diameter (-4 +/- 1 mm), moved the anterior papillary muscle closer to the annulus (2 +/- 1 mm), and relieved posterior leaflet apical restriction (2 +/- 1 mm, P < .05 papillary muscle repositioning vs chronic ischemic mitral regurgitation) but did not change lateral posterior papillary muscle displacement or decrease mitral regurgitation (1.9 +/- 1.2). CONCLUSIONS: Septal-lateral annular cinching moved the lateral annulus and the posterior papillary muscle closer to the septum and reduced mitral regurgitation unlike posterior papillary muscle repositioning, and thus the key mitral subvalvular repair component must correct posterior papillary muscle lateral displacement.     

Is mitral valve repair superior to replacement for chronic ischemic mitral regurgitation with left ventricular dysfunction?

Background  

This study was undertaken to compare mitral valve repair and replacement as treatments for ischemic mitral regurgitation (IMR) with left ventricular dysfunction (LVD). Specifically, we sought to determine whether the choice of mitral valve procedure affected survival, and discover which patients were predicted to benefit from mitral valve repair and which from replacement.     

Is repair preferable to replacement for ischemic mitral regurgitation?

OBJECTIVE: This study was undertaken to compare mitral valve repair and replacement as treatments for ischemic mitral regurgitation. METHODS: From 1985 through 1997, a total of 482 patients with ischemic mitral regurgitation underwent either valve repair (n = 397) or valve replacement (n = 85). Patients more likely (P < or =.01) to undergo repair had functional mitral regurgitation or coronary revascularization with an internal thoracic artery graft; those more likely to receive valve replacement were in higher New York Heart Association functional classes or underwent emergency operations. These factors were used for multivariable propensity matching. Risk factors for early and late death were identified by multivariable, multiphase hazard function analysis. RESULTS: Within the propensity-matched better-risk group, survivals after valve replacement were 81%, 56%, and 36% at 30 days, 1 year, and 5 years, but survivals after repair were 94%, 82%, and 58% at these intervals (P =.08). In contrast, within the poor-risk group, survivals after repair and replacement were similar (P =.4). Risk factors (P < or =.01) included older age, higher functional class, greater wall motion abnormality, and renal dysfunction. Approximately 70% of patients were predicted to benefit from repair; the benefit lessened or was negated if an internal thoracic artery graft was not used, if a lateral wall motion abnormality was present, or if the mitral regurgitation jet pattern was complex. Freedom from repair failure at 5 years was 91%. CONCLUSION: Late survival is poor after surgery for ischemic mitral regurgitation. Most patients with ischemic mitral regurgitation benefit from mitral valve repair. In the most complex, high-risk settings, survivals after repair and replacement are similar.     

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

Surgery Today - Ischemic mitral regurgitation (MR) is a common complication of myocardial infarction. Left ventricular (LV) dysfunction and distortion of the subvalvular apparatus are the main...     

Chronic ischemic mitral regurgitation: repair, replace or rethink?

Ischemic mitral regurgitation (IMR) is a common complication of coronary artery disease and is the focus of a rapidly increasing amount of research. Mechanistic studies have determined that IMR is caused by apical displacement and tethering of the mitral valve leaflets after myocardial infarction, resulting in incomplete coaptation. Despite the relatively high prevalence of IMR, most centers have only a small surgical experience with this disorder. The result is that a number of different procedures have been recently developed without clear improvement in patient outcomes. The current review will examine the myriad surgical options for IMR with a focus on clinical outcomes.     

Transient late-onset ischemic mitral regurgitation following Dor’s procedure

A 60-year-old man developed anteroseptal acute myocardial infarction with subsequent left hemiplegia. Echocardiography detected apical aneurysm with thrombus. Coronary artery bypass grafting with Dor’s procedure were performed. Chronic heart failure (CHF) developed three months after the surgery. CHF with mitral regurgitation (MR) continued for more than two months and then disappeared. When surgical intervention is considered for late MR after Dor’s procedure, it is important to consider that late-onset MR after Dor’s procedure can be transient with full medication, which may require four or more months to achieve its full effects.     

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.

In patients undergoing mitral surgery for ischaemic mitral regurgitation is it preferable to repair or replace the mitral valve?

A best evidence topic was written according to a structured protocol. The question addressed was whether patients undergoing coronary bypass grafting and mitral intervention for moderate to severe ischaemic mitral regurgitation are best treated with mitral repair or replacement. Five hundred and fifty papers were found using the reported search. Based on the 14 non-randomised studies judged to represent best evidence, we concluded that whilst there is some evidence that the operative mortality may be less following mitral valve repair, long-term data are equivocal. Even with contemporary techniques, recurrent mitral regurgitation is not uncommon following repair. Replacement was more frequently performed for patients with greater co-morbidity. Whilst two studies attempted to control for this using propensity analysis, in the majority of studies this introduced considerable bias. No data was available on long-term functional outcomes and quality of life. As there is currently insufficient evidence to inform clinical practice, a randomised trial is warranted in this important area.     

Is subvalvular repair worthwhile in severe ischemic mitral regurgitation? Subanalysis of the Papillary Muscle Approximation trial

Objective

The symmetry of mitral valve tethering and regional left ventricle wall dysfunction are reported to play a fundamental role in the outcomes and long-term durability of surgical repair in ischemic mitral regurgitation (IMR). We recently demonstrated in a randomized clinical trial (the Papillary Muscle Approximation trial) the superiority of papillary muscle approximation (PMA) in combination with standard restrictive annuloplasty (RA) in severe IMR over annuloplasty alone in terms of adverse left ventricular remodeling and mitral regurgitation (MR) recurrence. This approach, however, failed to produce a survival advantage and was still plagued by a high incidence of reoperation. We therefore performed a subanalysis of the PMA trial on the basis of preoperative parameters to elucidate the value of subvalvular surgery in certain subcategories of patients with the aim of creating a decisional algorithm on the best operative strategy.