Perioperative stroke is one of the most feared complications of any surgery or invasive medical procedure. Perioperative stroke occurs in less than 1% of patients undergoing general surgery,1 but the risk is several fold higher with cardiac surgery, carotid revascularization, other cerebrovascular procedures, and thoracic aortic repair. Given the volume of these interventions, perioperative and periprocedural stroke likely account for at least 5% of the approximately 800 000 strokes that occur each year in the United States,2 yet stroke in this setting remains understudied.