Risk factors for stroke include advanced age, history of stroke, diabetes mellitus, hyperten- sion,841 and female sex,842 with newer research emphasizing the importance of preoperative atherosclerotic disease (in- cluding radiographic evidence of previous stroke or aortic atheromatous disease).843 Although macroembolization and microembolization are major sources of stroke, hypoperfu- sion,844 perhaps in conjunction with embolization,845 is a risk factor for postoperative stroke. The mortality rate is 10-fold higher among post-CABG patients with stroke than among those without it, and lengths of stay are longer in stroke Although off-pump CABG was introduced in large part to reduce stroke and other adverse neurological outcomes asso- ciated with CPB, several RCTs comparing on-pump and off-pump CABG have shown no difference in stroke See Online Data Supplement 33 for additional data on stroke rates. 5.2.1.1.1. Use of Epiaortic Ultrasound Imaging to Reduce Stroke Rates: Recommendation Class IIa 1. Routine epiaortic ultrasound scanning is reasonable to evaluate the presence, location, and severity of plaque in the ascending aorta to reduce the incidence of atheroembolic complications.847 849 (Level of Evi- dence: B) Identification of an atherosclerotic aorta is believed to be an important step in reducing the risk of stroke after CABG.850 Intraoperative assessment of the ascending aorta for detection of plaque by epiaortic ultrasound imaging is superior to direct palpation and TEE.851,852 Predictors of ascending aortic atherosclerosis include increasing age, hypertension, extracardiac atherosclerosis (peripheral ar- tery and cerebrovascular disease), and elevated serum creatinine concentrations.853 855 Prospective RCTs to eval- uate the role of epiaortic scanning in assessing stroke risk have not been reported, but several observational studies reported stroke rates of 0 to 1.4%847 849,853,856,857 when surgical decision making was guided by the results of epiaortic scanning. 