Mitral-Valve Repair Versus Replacement for Severe Ischemic Mitral Regurgitation

Study Questions:

Among patients who undergo surgical intervention for severe ischemic mitral regurgitation (MR), is there a difference in left ventricular (LV) reverse remodeling after mitral valve repair compared to chordal-sparing mitral valve replacement?

Methods:

In a multicenter trial, 251 patients scheduled to undergo clinically indicated surgical intervention for severe ischemic MR (with or without concomitant coronary revascularization) were randomly assigned to undergo either mitral-valve repair or chordal-sparing replacement in order to evaluate efficacy and safety. The primary endpoint was LV end-systolic volume index (LVESVI) 12 months after intervention, as assessed with a Wilcoxon rank-sum test, in which deaths were categorized below the lowest LVESVI rank.

Results:

At 12 months, the mean LVESVI among surviving patients was 54.6 ± 25.0 ml/m2 body-surface area in the repair group and 60.7 ± 31.5 ml/m2 in the replacement group (mean change from baseline −6.6 and −6.8 ml/m2, respectively). Mortality was 14.3% in the repair group and 17.6% in the replacement group (hazard ratio with repair 0.79; 95% confidence interval, 0.42-1.47; p = 0.45). There was no significant between-group difference in LVESVI after adjustment for death (z score 1.33, p = 0.18). The rate of moderate or severe recurrent MR at 12 months was higher in the repair group than in the replacement group (32.6% vs. 2.3%, p < 0.001). There were no significant between-group differences at 12 months in the rate of a composite endpoint of major adverse cardiac or cerebrovascular events, in functional status, or in quality of life.

Conclusions:

There was no observed significant difference in LV reverse remodeling (assessed by LVSVI) or in survival 12 months after mitral-valve repair compared to chordal-sparing mitral valve replacement among patients with severe ischemic MR. Replacement provided a more durable correction of MR, but there was no significant between-group difference in clinical outcomes.

Perspective:

Ischemic MR is associated with a substantial risk of death; however, intervention for ischemic MR has never been shown to affect mortality. Practice guidelines recommend surgery for patients with severe ischemic MR at the time of coronary revascularization; intervention solely for ischemic MR without revascularization is not strongly recommended (American College of Cardiology/American Heart Association guideline Class IIb if performed in the setting of intractable heart failure despite maximum medical therapy and cardiac resynchronization therapy, if appropriate). Many surgeons advocate reduction/restrictive mitral annuloplasty as a means to treat ischemic MR. Depending on a variety of factors at least in part related to LV geometry, recurrent MR is not uncommon, though. This relatively small, but prospective randomized study suggests that, with limited outcome measurements, chordal-sparing mitral valve replacement might achieve similar clinical outcomes with less recurrent MR.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Implantable Devices, Cardiac Surgery and Arrhythmias, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Mitral Valve Insufficiency, Heart Failure, Ventricular Remodeling, Mitral Valve Annuloplasty, Cardiac Resynchronization Therapy


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