Effects of coronary revascularization with or without cardiopulmonary bypass on plasma levels of asymmetric dimethylarginine

Objectives: We measured and compared serum asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine levels in patients undergoing coronary artery revascularization. Methods: Two groups of patients with coronary artery disease were subjected to coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass (CPB; n=20) or with off-pump CABG surgery (OPCABG; n=21). Blood samples for measurements of ADMA, SDMA, and L-arginine were withdrawn and determined by liquid chromatography-tandem mass spectrometry from the coronary sinus (CS) and from the peripheral vein. Results: On the basis of the intraoperative (CS) samples, ADMA levels rose in the CPB group (F=0.416, P<0.685 and F=14.751, P<0.001 for OPCABG and CPB groups, respectively). A similar significant increase of ADMA was observed in the peripheral blood (F=30.738, P<0.001) during CPB, whereas ADMA levels remained unchanged during OPCABG. The time course of L-arginine levels was significantly different in the blood samples from CS (F=3.255, P<0.05), when compared with samples from the peripheral blood (F=3.255, P<0.05). The values of the L-arginine/ADMA ratio were significantly higher in the OPCABG group at baseline and on the first postoperative day compared with the results of the CPB group (178.29±11.56 vs. 136.28±13.72 and 129.43±7.08 vs. 106.8±6.9 for OPCABG and CPB groups, respectively). Conclusion: Plasma levels of ADMA, SDMA, L-arginine, and L-arginine/ADMA ratio are reliable and feasible markers of an early ischemia-reperfusion injury. During CPB operation, the plasma concentration of ADMA increased significantly and remained elevated until the first postoperative day due to extensive ischemia-reperfusion injury caused by CPB.