Adenosine preconditioning reduces myocardial injury in patients undergoing off-pump coronary artery bypass grafting surgery

Abstract

To evaluate the effects of adenosine on reducing myocardial injuries in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Forty patients undergoing OPCAB were allocated into two equal groups randomly: adenosine (ADO) group and control group. The patients in the ADO group were given infusion of adenosine through the central venous catheter via internal jugular vein when the surgeons dissociated the internal mammary artery. The initial infusion rate was 50 microg.kg(-1).min(-1), the infusion speed increased every minute until the dose of 150 microg.kg(-1).min(-1), and the total duration of adenosine infusion lasted for 10 min. The patients of the control group received intravenous infusion of 0.9% saline instead during the infusion period. 5 min after the completion of adenosine or saline infusion protocol, revascularization began. Blood samples were collected at following time points: T0 (10 minutes after anesthesia), T1, T2, T3, T4, and T5 (30 minutes, and 2, 6, 12, and 24 hours after revascularization respectively). Levels of MB isoenzyme of creatine kinase (CK-MB) and cardiac troponin I (cTnI) were measured. The CK-MB levels of the control group increased from T1 to T5 (all P < 0.05), and the CK-MB level of the ADO group increased only at T2 (P < 0.05), however, the level of CK-MB 24 h after revascularization of the control group was significantly higher than that of the ADO group (P < 0.05). The cTnI level increased significantly after revascularization (from T1 to T5) in both group (all P < 0.05), and the cTnI levels of the control group were higher than those of the ADO group at all time points, and were significantly higher at T4 and T5 points (both P < 0.05). OPCAB can cause myocardial injuries which can be reduced by adenosine preconditioning through the reduction of the release of CK-MB and cTnI.