Outcomes of Coronary Artery Bypass Grafting and Reduction Annuloplasty for Functional Ischemic Mitral Regurgitation: A Prospective Multicenter Study (Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve)

Study Questions:

What are the outcomes of reduction annuloplasty for ischemic mitral regurgitation (MR)?

Methods:

Twenty-one centers randomized 75 patients to the coronary artery bypass grafting + reduction annuloplasty subgroup that was the control arm of the Randomized Evaluation of a Surgical Treatment for Off-pump Repair of the Mitral Valve (RESTOR-MV) trial. Entry criteria included patients requiring revascularization, patients with severe or symptomatic moderate ischemic MR, left ventricular (LV) ejection fraction ≥25%, LV end-diastolic dimension ≤7.0 cm, and >30 days since acute myocardial infarction. Echocardiograms were independently analyzed at a core laboratory. Reduction annuloplasty was achieved by device annuloplasty. Two patients underwent immediate intraoperative conversion to valve replacement because reduction annuloplasty was unable to correct MR; as-treated results are presented.

Results:

An average of 2.8 bypass grafts were used per patient. Thirty-day mortality was 4.1% (3 of 73 patients). Mean follow-up was 24.6 months. MR was reduced from 2.6 ± 0.8 (out of 4+) preoperatively to 0.3 ± 0.6 at 2 years. Freedom from death or valve reoperation was 78% ± 5% at 2 years. There was significant improvement in LV ejection fraction and New York Heart Association functional class, with reduction of LV end-diastolic dimension. Cox regression analyses suggested that increasing age (p = 0.001; hazard ratio, 1.16 per year; 95% confidence interval, 1.06-1.26) and renal disease (p = 0.018; hazard ratio, 3.48; 95% confidence interval, 1.25-9.72) were associated with decreased survival.

Conclusions:

Coronary artery bypass grafting plus reduction annuloplasty for functional ischemic MR predictably reduces MR and relieves symptoms. This treatment of moderate to severe MR is associated with improved indices of LV function, improved New York Heart Association functional class, and excellent freedom from recurrent MR. Although long-term prognosis remains guarded, this multicenter study delineates the intermediate-term benefits of such an approach.

Perspective:

The RESTOR-MV trial sought to compare outcomes of surgical bypass + mitral annuloplasty to bypass + an LV reshaping device among patients with coronary disease and functional ischemic MR. The trial was terminated when the device sponsor failed to secure ongoing funding, but the results as published (Grossi EA, et al., J Am Coll Cardiol 2010;56:1984-93) suggested that use of the LV reshaping device was associated with improved survival at 2 years despite less MR in the control group. The present study of the control group finds the standard (albeit not universally adapted) therapy of surgical bypass plus mitral annuloplasty is associated with acceptable operative risks; effective reduction in MR ischemic severity; and reduction in LV size, increase in LV ejection fraction, and improvement in symptoms compared to preoperative measures. These data should reinforce the use of concomitant mitral annuloplasty at the time of surgical revascularization among patients with ischemic MR.

Clinical Topics: Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Valvular Heart Disease, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Imaging, Interventions and Structural Heart Disease, Echocardiography/Ultrasound, Mitral Regurgitation

Keywords: Myocardial Infarction, Follow-Up Studies, Ventricular Function, Left, Mitral Valve Insufficiency, Coronary Disease, New York, Prognosis, Heart Failure, Cardiac Surgical Procedures, Coronary Artery Bypass, Mitral Valve Annuloplasty, Mitral Valve, Echocardiography


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