Safety and Efficacy of Remote Ischemic Conditioning for Patients Taking Off-pump Coronary Artery Bypass Grafting

Inclusion Criteria: * Diagnosed with coronary artery disease and require off-pump CABG surgery. * Between 18 and 75 years old; * Normal left ventricular systolic function (ejection fraction \>40%) and left ventricular end-diastolic internal diameter (\<60 mm) in the cardiac ultrasound tests; * No or mild heart valve and great vessel abnormalities which do not require surgical intervention; * Participants or their authorized relatives agree to participate in the clinical trial and sign the informed consent. Exclusion Criteria: * Severe tissue injuries. * Myalgia, fractures and other peripheral vascular lesions. * Bypass graft being the radial artery. * Stenosis or severe malformations of the subclavian, jugular and femoral arteries and veins. * Previous vagus nerve trunk dissection or vagus nerve block surgery. * Other surgical operations at the same time. * Patients with pre-existing severe cardiac insufficiency, acute coronary syndromes, malignant hypertension and cardiogenic shock. * Severe coagulation abnormality or severe anemia. * Severe mental disorder. * Malignant tumors. * Pregnant or lactating. * Increased risk of treatment for patients, according to investigators. * Refuse to sign the informed consent form.