Objective. Cardiac surgery is the leading cause of iatrogenic stroke in the United States; 1% to 5% of patients undergoing CABG have a stroke, and 30% have clinically silent new lesions that are detectable only on MRI. Cognitive dysfunction is also common after heart surgery, and up to 40% have long-term cognitive impairment. The primary objective of this study is to define the pre-operative risk profile that best predicts postoperative ischemic or cognitive changes in patients undergoing heart surgery and to 1) establish a registry of patients undergoing cardiac surgery to evaluate the relationship of new lesions on MRI, blood biomarkers, neurological and neurocognitive outcome 2) identify the most significant risk factors for post operative cerebral ischemic lesions 3) determine whether new ischemic lesions on DWI are associated with subsequent neurological or cognitive impairment. The objective of the genetics sub-study is to estimate the relative risk of specific polymorphisms of genes of molecules involved in the inflammatory response and occurrence of new ischemic lesions.