**Abstract**

Coronary artery bypass grafting in patients with low ejection fraction is a highrisk operation because of high incidence of postoperative low cardiac output syndrome. Impella 5.0/5.5 is a surgically implanted left ventricular assist device that can unload the left ventricle. It is capable of full circulatory support. A perioperative use of Impella 5.0/5.5 can potentially improve the surgical outcomes of high-risk coronary artery bypass grafting by avoiding postoperative low cardiac output syndrome. However, the outcomes of Impella 5.0/5.5-supported coronary artery bypass grafting have not been reported frequently. In this chapter, the most recent evidence and the pros and cons of the Impella 5.0/5.5 use at the time of high-risk coronary artery bypass grafting are discussed.

**Keywords:** Impella 5.0/5.5, high-risk coronary artery bypass grafting, low cardiac output syndrome, surgical outcomes, cardiac physiology
