Aortic valve replacement for aortic stenosis in patients with concomitant mitral regurgitation: should the mitral valve be dealt with?

Co-existent mitral regurgitation may adversely influence both morbidity and mortality in patients undergoing aortic valve replacement for severe aortic stenosis. Whilst it is accepted that concomitant mitral intervention is required in severe, symptomatic mitral regurgitation, in cases of mild–moderate non-structural mitral regurgitation, improvement may be seen following aortic valve replacement alone, avoiding the increased risk of double-valve surgery. The exact benefit of such a conservative approach is, however, yet to be adequately quantified. We performed a systematic literature review identifying 17 studies incorporating 3053 patients undergoing aortic valve replacement for aortic stenosis with co-existing mitral regurgitation. These were meta-analysed using random effects modelling. Heterogeneity and subgroup analysis were assessed. Primary end points were change in mitral regurgitation severity and 30-day, 3-, 5- and 10-year mortality. Secondary end points were end-organ dysfunction (neurovascular, renal and respiratory), and the extent of ventricular remodelling following aortic valve replacement. Our results revealed improvement in the severity of mitral regurgitation following aortic valve replacement in 55.5% of patients, whereas 37.7% remained unchanged, and 6.8% worsened. No significant difference was seen between overall data and either the functional or moderate subgroups. The overall 30-day mortality following aortic valve replacement was 5%. This was significantly higher in moderate–severe mitral regurgitation than nil–mild mitral regurgitation both overall (p = 0.002) and in the functional subgroup (p = 0.004). Improved long-term survival was seen at 3, 5 and 10 years in nil–mild mitral regurgitation when compared with moderate–severe mitral regurgitation in all groups (overall p < 0.0001, p < 0.00001 and p = 0.02, respectively). The relative risk of respiratory, renal and neurovascular complications were 7%, 6% and 4%, respectively. Reverse remodelling was demonstrated by a significant reduction in left-ventricular end-diastolic diameter and left-ventricular mass (p = 0.0007 and 0.01, respectively), without significant heterogeneity. No significant change was seen in left-ventricular end-systolic diameter (p = 0.10), septal thickness (p = 0.17) or left atrial area (p = 0.23). We conclude that despite reverse remodelling, concomitant moderate–severe mitral regurgitation adversely affects both early and late mortality following aortic valve replacement. Concomitant mitral intervention should therefore be considered in the presence of moderate mitral regurgitation, independent of the aetiology.     

Does the additive risk of mitral valve repair in patients with ischemic cardiomyopathy prohibit surgical intervention?

OBJECTIVE: To assess the surgical risk of additional mitral valve repairs in patients with ischemic cardiomyopathy. SUMMARY BACKGROUND DATA: Severe mitral regurgitation in patients with ischemic cardiomyopathy increases the death rate and symptomatic status. The 1-year survival rate for medical therapy in this subset of patients is less than 20%. Transplantation is usually not feasible because of donor shortage and death while on the waiting list. METHODS: To assess additive risk, a retrospective chart review from 1993 to 1998 was performed comparing patients with ischemic cardiomyopathy (ejection fraction [EF] <25%) and severe mitral regurgitation undergoing mitral valve repair and coronary artery bypass graft operations with patients with an EF of <25% undergoing coronary artery bypass graft alone. These groups were also compared with 140 patients receiving heart transplants since 1993 (group 3). RESULTS: The overall hospital death rate for group 1 was 6.3%. The one death occurred 2 weeks after surgery secondary to sepsis. This was not significantly different from the death rate of 4.1% in group 2. In group 1, there were two deaths at 1 year (87% survival rate), one related to heart failure. One patient was New York Heart Association (NYHA) class IV at 1 year; the remainder of patients were NYHA class I-II. These results were not significantly different than the 8% death rate noted with transplantation. There was no change in EF and minimal residual mitral regurgitation in group 1 based on postoperative transesophageal echocardiography, whereas group 2 had an average 11.7% improvement in EF. CONCLUSIONS: Previously, severe mitral regurgitation in the setting of ischemic cardiomyopathy has been associated with poor survival. In these authors' experience, repairing the mitral valve along with coronary artery bypass grafting does not increase the surgical risk, yields improvement in symptomatic status, and compares favorably to coronary artery bypass grafting alone and cardiac transplantation. However, the lack of change in EF in these patients probably represents an overestimation of the EF before surgery secondary to severe mitral regurgitation.     

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.     

Should patients undergoing coronary artery bypass grafting with mild to moderate ischaemic mitral regurgitation also undergo mitral valve repair or replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether mitral valve repair at the time of coronary artery bypass grafting (CABG) in patients with coronary artery disease and mild to moderate mitral insufficiency improves short and long-term outcome. Altogether 465 papers were found using the reported search, of which 16 presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that there is good evidence to suggest that moderate mitral regurgitation in patients undergoing isolated CABG adversely affects survival and mitral regurgitation does not reliably improve after CABG alone. Unfortunately, the evidence to support mitral valve repair at the time of CABG to improve long-term survival is still weak. On balance, patients with moderate ischaemic mitral regurgitation having CABG should have mitral repair at the same time, although the evidence to support this is weaker than one might like.     

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.     

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...     

In patients with concomitant aortic and mitral valve disease is aortic valve replacement with mitral valve repair superior to double valve replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients with concomitant aortic and mitral valve disease is aortic valve replacement with mitral valve plasty (MVP) superior to double valve replacement (DVR) in terms of improved long-term survival? Altogether 156 papers were found using the reported search, of which seven represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Out of seven papers, that simultaneously compare these two treatment modalities, three favor MVP combined with aortic valve replacement (AVR) over DVR, two papers advocate the opposite and two failed to find any significant difference in long-term survival, freedom from reoperation and thromboembolic and bleeding complications between these two surgical options. All data presented derive from level 2b evidence. Critical appraisal of these studies is constricted by the large heterogeneity of the patients, diversity in treatment protocols and inherent selection bias. We conclude that currently the available evidence is insufficient to prove that AVR with MVP is superior to DVR in patients with double valve disease.     

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.