Multiple studies have reported that dexmedetomidine has a protective effect on specific organs including heart, brain, kidney and lungs. In addition, dexmedetomidine has been shown to have anti-inflammatory properties decreasing mortality and attenuating plasma cytokine concentrations in laboratory animals exposed to endotoxin in a dose-dependent fashion. The investigators hypothesized that dexmedetomidine may provide myocardial, brain, renal and immune function protection for cardiovascular surgical patients. The specific aim of this study was to investigate whether the perioperative use of dexmedetomidine is associated with improved outcomes and a decreased incidence in postoperative mortality, MACE or other complications in patients undergoing open-heart surgery.