Which is first: Left anterior descending artery anastomosis or right coronary artery anastomosis in off-pump coronary artery bypass grafting?

Abstract

Objectives: The sequence of the distal anastomosis for revascularization in off-pump coronary artery bypass grafting (OPCABG) surgery is under debate. The hypothesis in this study was that an analysis of cardiac markers would reveal that anastomosing the left anterior descending coronary artery (LAD) before the right coronary artery (RCA) would decrease myocardial damage in OPCABG surgery for 2-vessel disease. Methods: Forty patients with stable angina who underwent OPCABG surgery and who had LAD and RCA lesions were randomized into 2 groups of 20 patients each. The LAD was revascularized first in group 1, and the RCA was revascularized first in group 2. Cardiac troponin I, creatine kinase (CK), and CK myocardial band (CK-MB) were measured in the 2 groups before surgery and at 8, 24, and 48 hours after surgery. Results: No mortality occurred in the 2 groups. The groups were similar with respect to sex, age, durations of anastomosis of the left internal thoracic artery to the LAD and of the saphenous vein graft to the RCA, and preoperative CK, CK-MB, and troponin I levels. Postoperative CK-MB levels were significantly higher in group 2 in the eighth and 24th postoperative hours than in group 1 (P = .009 and .041, respectively). Similarly, troponin I levels were significantly higher in group 2 in the eighth, 24th, and 48th hours than in group 1 (P = .003, .003, and .006, respectively). Conclusions: Anastomosis to the LAD first in OPCABG surgery led to a slight reduction in myocardial enzyme release against the occlusion of the target vessels during anastomoses in patients with RCA and LAD stenoses.