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; 138(2):278-85JT
Surgical management of moderate chronic ischemic mitral valve regurgitation is still debated. The aim of this study was to evaluate the effect of adding mitral valve repair to coronary artery bypass grafting on clinical outcomes and left ventricular remodeling in patients who underwent coronary artery bypass grafting alone versus coronary artery bypass grafting plus mitral valve repair in a randomized trial.
Between February 2003 and May 2007, 102 patients were eligible for this study and were randomly assigned to one of 2 groups by means of card allocation: coronary artery bypass grafting plus mitral valve repair (CABG plus MVR group; 48 patients, 47%) or coronary artery bypass grafting alone (CABG group; 54 patients, 53%). The 2 groups were similar regarding demographics, perioperative clinical data, and outcomes. There were differences regarding cardiopulmonary bypass (P < .0001) and aortic crossclamp (P < .0001) times. Exercise tests were performed for all survivors to evaluate tolerance to exercise and variability on grade of mitral regurgitation and systolic pulmonary arterial pressure. The study was blinded for physicians and nurses involved in postoperative care and clinical follow-up. The mean follow-up was 32 +/- 18 months.
Overall in-hospital mortality was 3% (3 patients). One (1.8%) patient died in the CABG group, and 2 (4.1%) patients died in the CABG plus MVR group. Survival rates +/- standard error at 5 years for patients in the CABG and CABG plus MVR groups were 88.8% +/- 3.2% and 93.7% +/- 3.1%, respectively. A significant difference was found between the 2 groups with regard to mean New York Heart Association class (P < .0001), left ventricular end-diastolic diameter (P < .01), left ventricular end-systolic diameter (P < .01), pulmonary arterial pressure (P < .0001), and left atrial size (P < .01). At follow-up, coronary artery bypass grafting alone was able to reduce mitral regurgitation grade in 40% of patients, whereas in the remaining patients mitral regurgitation grade remained stable or worsened. In the CABG group, among the 17 patients with mild mitral regurgitation and 12 patients with moderate mitral regurgitation at rest, 7 (40%) and 9 (75%) patients, respectively, had worsening in mitral regurgitation grade and pulmonary artery pressure during exercise.
The efficacy of adding mitral valve repair to coronary artery bypass grafting is well demonstrated by the improvement of New York Heart Association functional class and percentage of left ventricular ejection fraction and by the decrease of mitral regurgitation grade, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, pulmonary artery pressure, and left atrial size. Moreover, coronary artery bypass grafting alone left more patients with heart failure symptoms at rest and during exercise. Combined coronary artery bypass grafting and mitral valve repair have no effect on survival at short-term follow-up, and the trends that are evident will likely become more significant with time.