In the OPCAB group, the revascularization procedure will be performed on the beating heart with a stabilizer to demobilize the target coronary arteries. When access is needed for posterior coronary arteries a suction device will lift the heart. In the CCABG group, the revascularization procedure will be performed with the use of a heart- and lung machine in normothermia, aortic cross clamp, and with cold cardioplegic arrest. In both groups, the left internal mammary artery and saphenous vein grafts are standard graft material.