Litton E, et al. - This investigation was carried out to inform the design of a pivotal randomized controlled trial of prophylactic intra-aortic balloon counterpulsation (IABC) in patients undergoing coronary artery bypass graft (CABG) at high risk of postoperative low cardiac output syndrome (LCOS). Among patients at risk of LCOS, a group was identified in whom a substantial burden of perioperative morbidity was reported in relation to CABG surgery. Furthermore, variable preoperative IABC use was noted.