BACKGROUND:~Approximately 400,000 individuals undergo heart operations each year and cognitive impairment occurs frequently following surgery. An increasing number of these individuals are elderly and are particularly susceptible to cognitive dysfunction following surgery. Cognitive impairment is most notable in the early stages following heart surgery, but it may persist in some individuals. While many people think cognitive impairment is subtle, transient, or subclinical, perioperative decline is associated with 5-year cognitive deterioration and reduced quality of life. Multiple strategies, both clinical and pharmacological, have been proposed to reduce the central nervous system dysfunction associated with heart surgery. However, most strategies have been unsuccessful, met with limited success, or are unrealistic from a cost or risk-benefit ratio for the majority of people. This study will examine the effectiveness of supplemental magnesium at preventing the cognitive decline associated with heart surgery.~DESIGN NARRATIVE:~This study will examine the effect of supplemental magnesium on the neurocognitive function of individuals undergoing CABG surgery. The two hypotheses to be tested include the following: 1) therapeutic levels of magnesium reduce post-operative neurocognitive dysfunction after heart surgery; and 2) therapeutic magnesium levels protect quality of life through reduced cognitive dysfunction after heart surgery. This double-blind study will enroll 400 individuals and randomly assign them to either the treatment group, which will receive 100 mg/kg of magnesium, or to the control group. Anesthesia management will be standardized to minimize any impact that anesthesia may have on neurologic or neuropsychologic outcome. Neurocognitive testing will be conducted prior to surgery, and 6 weeks and 1 year following surgery.
The purpose of this study is to examine the effects of supplemental magnesium on the neurocognitive function of individuals undergoing coronary artery bypass graft (CABG) surgery.