Coronary artery bypass grafting(CABG) is an effective procedure in treating severe coronary artery disease(CAD). Optimal surgical method for CAD patients with functional ischemic mitral regurgitation(FIMR) is still controversial. This study will evaluate the different effectiveness of CABG plus mitral valve annuloplasty versus CABG alone on patients with moderate FIMR.

CAD is a severe health problem worldwide. It is a result of plaque buildup, and eventually leads to the reduction of blood supply on myocardium. CABG is one of the procedure to improve symptoms caused by myocardial ischemia. And it is especially effective in treating severe coronary artery disease.

FIMR is one of the most common complications of CAD. After acute myocardial infarction, FIMR will occur in 17%-55% patients, and 3%-19% of them will develop into moderate or severe MR eventually. FIMR is an important prognostic factor of CAD, the in-hospital mortality rate of patients with IMR is significantly higher in several studies. In patients with mild MR, CABG alone is enough to improve myocardial ischemia; however, in people with moderate mitral regurgitation, there is still a dispute on whether mitral valve annuloplasty is beneficial at the time of CABG. The purpose of this study is to determine the optimal surgical procedure of CAD patients combined moderate FIMR.

This study will compare the effectiveness of different surgical procedure on people with moderate FIMR by enrolling people with enrolling people with CAD who require CABG procedure and have moderate mitral regurgitation. At baseline study, a questionnaire will be assigned to undergo either CABG surgery of CABG plus mitral calve annuloplasty. Blood, urine and tissue samples will be collected after the surgery. All participants will be followed up at month 1,3,6,12, participants will take part in a medication history review, a physical examination, a blood collection to evaluate the brain natriuretic peptide and an echocardiogram.

Inclusion Criteria:

1. CAD that is amenable to CABG and a clinical indication for revascularization
2. Moderate mitral regurgitation in the judgment of the clinical site echocardiographer, quantitative guidelines as proposed would be: jet area between 4 cmsq to 8 cmsq, jet area/left atrial area ratio between 20% to 39%
3. Age ≥ 18 years
4. Mitral valve annuloplasty is applicable

Exclusion Criteria:

1. Organic mitral insufficiency caused by rupture of papillary muscle, rheumatic fever, degeneration or infectious endocarditis
2. Jet area of mitral valve cannot be evaluated by echocardiogram
3. In combination of other procedures such as surgery on tricuspid valve, aortic valve, congenital heart diseases or diseases of the thoracic arteries
4. Prior surgical or percutaneous mitral valve repair
5. Contraindication to cardiopulmonary bypass (CPB)
6. Clinical signs of cardiogenic shock at the time of randomization
7. Treatment with medication prior to the surgery
8. Severe, irreversible pulmonary hypertension in the judgment of the investigator
9. Evidence of cirrhosis or liver synthetic failure
10. Recent history of psychiatric disease (including drug or alcohol abuse) that is likely to impair compliance with the study, in the judgment of the investigator