In such individuals, off-pump CABG in conjunction with avoid- ance of manipulation of the ascending aorta (including placement of proximal anastomoses) may be beneficial. Surgeons typically prefer an on-pump strategy in patients with hemodynamic compromise because CPB offers sup- port for the systemic circulation. In the end, most surgeons consider either approach to be reasonable for the majority of subjects undergoing CABG. 2.1.4. Bypass Graft Conduit: Recommendations Class I 1. If possible, the left internal mammary artery (LIMA) should be used to bypass the left anterior descending (LAD) artery when bypass of the LAD artery is indicated.86 89 (Level of Evidence: B) Class IIa 1. The right internal mammary artery (IMA) is prob- ably indicated to bypass the LAD artery when the LIMA is unavailable or unsuitable as a bypass conduit. (Level of Evidence: C) 2. When anatomically and clinically suitable, use of a second IMA to graft the left circumflex or right coronary artery (when critically stenosed and per- fusing LV myocardium) is reasonable to improve the likelihood of survival and to decrease reinterven- tion.90 94 (Level of Evidence: B) Class IIb 1. Complete arterial revascularization may be reason- able in patients less than or equal to 60 years of age with few or no comorbidities. (Level of Evidence: C) 2. Arterial grafting of the right coronary artery may be reasonable when a critical (>90%) stenosis is pres- ent.89,93,95 (Level of Evidence: B) 3. Use of a radial artery graft may be reasonable when grafting left-sided coronary arteries with severe stenoses (>70%) and right-sided arteries with criti- cal stenoses (>90%) that perfuse LV myocardi- um.96 101 (Level of Evidence: B) Class III: HARM 1. 