“…All studies were published between 2006 and 2016, and the durations of follow-up ranged from 1 to 42 months. Ten studies examined prophylactic use of the Impella device among high-risk patients undergoing elective PCI [6,7,12,14,16,18,21,22,24,25], 5 examined its use among high-risk patients undergoing emergent PCI [5,8,13,20,26,27], and 4 examined its use in mixed populations of high-risk patients undergoing elective or emergent PCI [15,17,19,23]. The 4 RCTs contained a total of 438 patients; 1 RCT compared the Impella device to IABP in highrisk patients with left main disease or multivessel disease undergoing elective PCI [6], while 2 RCTs compared the use of the Impella device and IABP in the setting of emergent PCI in patients with cardiogenic shock and MI [5,27].…”