This trial will address essential questions of the efficacy and safety of MICS-CABG in addition to the quality of life and patency rate of the grafts. The study will also address the impact of patients' preferences on external validity and internal validity.

In this study, patients with a preference will be allocated to treatment strategies accordingly, whereas only those patients without a distinct preference will be randomized. The randomized trial is a 248-patient controlled, randomized, investigator-blinded trial. It is designed to compare whether treatment with MICS-CABG is beneficial in comparison to CABG. This study is aimed to establish the superiority hypothesis for the physical component summary (PCS) accompanied by the noninferiority hypothesis for overall graft patency. Patients with no treatment preference will be randomized in a 1:1 fashion to one of the two treatment arms.

The primary efficacy endpoints are the PCS score at 30 days after surgery and the overall patency rate of the grafts within 14 days after surgery. Secondary outcome measures include the PCS score and patency rate at different time points. Safety endpoints include major adverse cardiac and cerebrovascular events, complications, bleeding, wound infection, death, etc.

Inclusion Criteria:(A patient will be included in the study when the following criteria and requirements are met)

① Patient age of ≥25 years but ≤85 years, and patients with CAD who require multivessel coronary bypass surgery. ② Angina that affects daily life and work and is uncontrollable with conservative treatment. ③ Significant stenosis in the left main (LM) coronary artery, left anterior descending (LAD) branch or left circumflex (LCX) branch >70%. ④ Severe stenosis (stenosis degree >75%) of three main branches of the coronary artery (anterior descending branch, circumflex branch, right coronary artery) with the need to undergo off-pump coronary artery bypass surgery.

Exclusion Criteria:(A patient will be excluded from the study if they meet any of the following criteria)

① Unstable preoperative hemodynamic status (vasoactive drugs such as dopamine, epinephrine or norepinephrine to maintain blood pressure, or an intra-aortic balloon pump [IABP] is implanted preoperatively) or requiring emergency surgery. ② Severe emphysema, hypoxemia [postbronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC)<70% and FEV1% predicted<50% or partial pressure of oxygen (pO2)<60 mmHg or partial pressure of carbon dioxide (pCO2)>40 mmHg without oxygen therapy. ③ Old extensive myocardial infarction without a viable myocardium based on isotope and echocardiography examination, significant cardiac enlargement (cardiothoracic ratio>0.75, EF<30%, left ventricular diastolic diameter (LVDd)>60 mm, left ventricular aneurysm or severe arrhythmia). ④ Severe pleural adhesion, chest deformity, or previous thoracic radiotherapy. ⑤Previous thoracotomy surgery. ⑥ Simultaneous valve or other cardiac surgery. ⑦Planned cardiopulmonary bypass surgery. ⑧Poor condition of the distal coronary artery (diffuse stenosis, chronic total obstructive lesion with severe calcification or inability to match the graft due to a small diameter (<1.0 mm). ⑨Intolerance to surgery in combination with the following complications: Terminal cancer, uncontrolled infection, bleeding, severe brain injury, infarction or bleeding, multiple organ failure and other major organ dysfunction such as severe liver dysfunction or severe congestive heart failure.](streamdown:incomplete-link)