Study population - A total of 140 patients (70 per each group) will be randomized. Subjects will be neurologically independent adult patients undergoing non-emergency CABG who are appropriate for either on- or off-pump surgery. In the observational study we will also assemble a cohort of 100 consecutive patients that will have CABG and 100 consecutive patients that will have valve replacement surgery. Total accrual across both studies will be 340 patients.