ReviewMitral Valve Repair or Replacement for Ischaemic Mitral Regurgitation: A Systematic Review
Introduction
Chronic ischaemic mitral regurgitation (IMR) occurs in up to 40% of patients following myocardial infarction [1], and is a major risk factor for adverse outcomes such as impaired ventricular function or death [2]. The characteristic echocardiographic and macroscopic appearance of IMR is a result of complex changes in the geometry and function of the left ventricle and annulus. This is usually caused by myocardial infarction in the distribution of the circumflex or right coronary artery, producing a variable combination of annular dilatation (Carpentier type I dysfunction) and systolic leaflet restriction (Carpentier type IIIb dysfunction) [3].
Few surgeons would advocate either mitral valve (MV) repair or replacement for mild IMR because coronary artery bypass graft (CABG) alone often results in satisfactory resolution of the mitral regurgitation. Outcomes following CABG alone in patients with mild MVR are only marginally worse than in patients with no mitral regurgitation [4] and it has been estimated that only about 3% of patients will subsequently require admission for congestive heart failure [5].
The difficulty arises in determining the management of patients with moderate or severe IMR as CABG alone does not cure the valve insufficiency in this group. Moderate to severe IMR is associated with significantly reduced survival following CABG [6], [7] and about half of patients with moderate IMR undergoing CABG will require future admission for congestive heart failure [5]. Many surgical groups involved in the study of IMR have advocated doing a randomised trial of CABG alone versus CABG with mitral valve intervention in patients with at least moderate IMR [6], [7], [8]. One recent randomised study has already reported significant improvement in terms of symptoms and reversed remodelling at a mean follow-up of three years following mitral valve repair and CABG compared to CABG alone [9]. Although an improvement in survival has only been demonstrated in case series [10], [11], several other randomised trials are currently recruiting patients (NCT00838786, NCT00806988, NCT00443365, NCT00613548, NCT00919256).
The choice of surgical intervention to treat patients with moderate to severe IMR remains problematic as there is no consensus in the literature about whether MV repair (MV-Repair) or MV replacement (MV-Replacement) is more effective. Consequently, we aimed to review the findings of previous studies which have compared these techniques. Our review aims to estimate whether there are differences between patients with IMR undergoing MV-Repair or MV-Replacement with respect to (a) operative mortality, (b) need for reoperation, (c) survival, (d) function and (e) health-related quality of life (HRQoL).
Section snippets
Literature Search
A literature search was performed in Pubmed, Embase, Ovid and Google Scholar for studies published between 1965 and 2010 without language restriction. The following Medical Subject Headings (MeSH) were used: mitral valve*, replantation*, heart valve prosthesis*, heart valve prosthesis implantation*, ischemia*, myocardial ischemia*, and mitral valve insufficiency*. Complementary searches were also performed with the following free text: “mitral valve repair”, “mitral valve replacement”, and
Eligible Studies
The literature search identified 2032 studies, which were published between 1965 and 2010. On the basis of title and abstracts, 42 articles were obtained and reviewed in full. Twelve articles met the inclusion and exclusion criteria (Fig. 1) [4], [8], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32]. All were retrospective and non-randomised. All studies reported 30-day mortality [4], [8], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], five reported re-operation rates [8]
Discussion
The risk of bias to the included studies precludes robust synthesis of their individual findings quantitatively [33]. Nevertheless, the forest plots (Figure 2, Figure 3) qualitatively suggest that MV-Repair tends to be associated with lower peri-operative mortality and longer survival than MV-Replacement in patients with IMR. HRs calculated for studies adjusted for confounding tended to be more, rather than less, extreme than HRs for unadjusted other studies, but were nevertheless moderately
Conclusion
This review suggests that MV-Repair is associated with lower 30-day mortality and may be associated with improved longer term survival. However, there is considerable uncertainty about this finding because included studies were heterogeneous and at risk of confounding and other biases.
Acknowledgments
No external funding was received for this study. Barnaby Reeves is supported in part by the National Institute for Health Research Bristol Biomedical Research Unit in Cardiovascular Medicine.
References (55)
- et al.
Reconstructive surgery of mitral valve incompetence: ten-year appraisal
J Thorac Cardiovasc Surg
(1980) - et al.
Survival prognosis and surgical management of ischemic mitral regurgitation
Ann Thorac Surg
(2008) - et al.
Late outcomes in patients with uncorrected mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting
J Thorac Cardiovasc Surg
(2004) - et al.
Importance of moderate ischemic mitral regurgitation
Ann Thorac Surg
(2005) - et al.
Mitral repair versus replacement for ischemic mitral regurgitation
Ann Thorac Surg
(2005) - et al.
POINT: efficacy of adding mitral valve restrictive annuloplasty to coronary artery bypass grafting in patients with moderate ischemic mitral valve regurgitation: a randomized trial
J Thorac Cardiovasc Surg
(2009) - et al.
Moderate-to-severe ischemic mitral regurgitation and multivessel coronary artery disease: impact of different treatment on survival and rehospitalization
Int J Cardiol
(2006) - et al.
Relation of frequency and severity of mitral regurgitation to survival among patients with left ventricular systolic dysfunction and heart failure
Am J Cardiol
(2003) - et al.
Meta-analysis in clinical trials
Control Clin Trials
(1986) - et al.
Mitral valve surgery for chronic ischemic mitral regurgitation
Ann Thorac Surg
(2004)
Is repair preferable to replacement for ischemic mitral regurgitation?
J Thorac Cardiovasc Surg
Ischemic mitral valve reconstruction and replacement: comparison of long-term survival and complications
J Thorac Cardiovasc Surg
Long-term survival after surgical revascularization for moderate ischemic mitral regurgitation
Ann Thorac Surg
Adding mitral valve annuloplasty to surgical revascularization does not benefit patients with functional ischemic mitral regurgitation
J Am Coll Cardiol
Repair of ischemic mitral regurgitation does not increase mortality or improve long-term survival in patients undergoing coronary artery revascularization: a propensity analysis
Ann Thorac Surg
Can late survival of patients with moderate ischemic mitral regurgitation be impacted by intervention on the valve?
Ann Thorac Surg
Impact of mitral valve annuloplasty combined with revascularization in patients with functional ischemic mitral regurgitation
J Am Coll Cardiol
Restrictive annuloplasty for ischemic mitral regurgitation may induce functional mitral stenosis
J Am Coll Cardiol
Insights on left ventricular and valvular mechanisms of recurrent ischemic mitral regurgitation after restrictive annuloplasty and coronary artery bypass grafting
J Thorac Cardiovasc Surg
Papillary muscle sling: a new functional approach to mitral repair in patients with ischemic left ventricular dysfunction and functional mitral regurgitation
Ann Thorac Surg
Surgical relocation of the posterior papillary muscle in chronic ischemic mitral regurgitation
Ann Thorac Surg
Effectively treating ischemic mitral regurgitation with chordal cutting in combination with ring annuloplasty and left ventricular reshaping approach
J Thorac Cardiovasc Surg
Ischemic mitral regurgitation redux—to repair or to replace?
J Thorac Cardiovasc Surg
Ischemic mitral regurgitation and risk of heart failure after myocardial infarction
Arch Intern Med
Clinical significance of mitral regurgitation after acute myocardial infarction. Survival and Ventricular Enlargement Investigators
Circulation
Does coronary artery bypass grafting alone correct moderate ischemic mitral regurgitation?
Circulation
Mitral valve repair versus replacement for isolated non-ischemic mitral regurgitation in patients with preoperative left ventricular dysfunction. A long-term follow-up echocardiography study
Eur J Echocardiogr
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Repair or Replacement for Secondary Mitral Regurgitation: Results From Polish National Registry
2022, Annals of Thoracic SurgeryCitation Excerpt :We estimated that for every 18 people treated with repair as opposed to replacement, 1 life would be spared (Figure 3). While lower early mortality with MV repair was visible in many studies10-15 and some meta-analyses,9,16,17 the long-term results were almost invariably not significantly different between the groups.5,9,11,12,15,16,18-20 However, the numeric difference in most studies and meta-analyses concurs with our findings, suggesting that many of the reports were simply underpowered to find the difference.
Surgical Management of Severe Ischaemic Mitral Regurgitation
2018, Heart Lung and CirculationCitation Excerpt :In a recent systematic review, Rao et al. summarised the previous literature and found that CABG concomitant with MVP could provide lower operative mortality and higher long-term survival rate. But the report also mentioned that the conclusion was not absolute, because many previous studies were not uniform [5]. Additionally, Acker reported the first prospective randomised study to compare MVP with MVR for severe IMR.
Similar survival after mitral valve replacement or repair for ischemic mitral regurgitation: A meta-analysis
2014, Annals of Thoracic SurgeryCitation Excerpt :Debate exists about the benefit of MVR or MVP regarding hospital mortality, survival, ventricular remodeling, and changes in LVEF, among other functional indicators in patients with IMR. Previous meta-analyses [12, 34] confirmed that MVR is associated with increased hospital mortality and lower survival. We have included a total of 12 studies that address the outcomes of MVP versus MVR for IMR.
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