Study on the Myocardial Protective Effect of Upper Limb Ischemic Preconditioning in Patients Undergoing Off-pump Coronary Artery Bypass Grafting

Study on the Myocardial Protective Effect of RIPC in Patients Undergoing OPCABG

The purpose of the study was to verify the myocardial protective effect of RIPC in patients undergoing OPCABG.

66 patients scheduled for OPCABG are randomly assigned to a RIPC group(n=33) or a control group(n=33). In the RIPC group, 4 cycles of 5-min ischemia(using a blood pressure cuff inflated to 40mmHg over the patient's basic blood pressure) and 5-min repercussion are done on an upper limb before skin incision. Patients in the control group wear the same cuff on an upper limb but no pressure is applied. Anesthetic and surgical techniques are standardized during the trial. Serum inflammatory cytokines and cardiac injury markers will be measured before and after surgery. Internal mammary artery and saphenous vein tissues will be collected during the surgery to assess hypoxia-inducible factor (Hif)-1a and other signalling proteins.

Inclusion Criteria:

• serious changes in several coronary arteries that need to receive OPCABG
• NHYA II-III
• ASA II-III

Exclusion Criteria:

• LVEF< 35%
• acute myocardial infarction
• multiple organ dysfunction