Estrogen Replacement to Reduce Risk of Neurologic Injury After Coronary Artery Bypass Graft Surgery

BACKGROUND: Women undergoing CABG surgery have a higher operative mortality rate, longer hospitalizations, and higher hospital costs compared with men. A large proportion of this excess morbidity and mortality of surgery for women is due to perioperative neurologic injury. Estrogen has been consistently shown to reduce the extent of neurologic injury in a variety of in vitro and animal experimental stroke models. These data together strongly suggest that the higher risk for perioperative neurologic complications for elderly women may relate to their estrogen deficient state. DESIGN NARRATIVE: This randomized, placebo controlled study will test the hypothesis that perioperative estrogen replacement in postmenopausal women reduces the risk for neurologic injury after CABG surgery. Three hundred thirty-four women undergoing CABG surgery will be prospectively randomized to receive either 17 beta-estradiol or placebo in a double-blind fashion beginning the day before surgery and continuing for 5 days after surgery. Patients will be assessed for neurocognitive dysfunction, which is the most common manifestation of neurologic injury from cardiac surgery. Neurocognitive testing will be performed 1 to 2 days before surgery, 4 to 6 weeks postoperatively, and 6 months after surgery. The primary endpoint will be neurocognitive function 4 to 6 weeks after surgery for women who received 17 beta- estradiol compared with placebo perioperatively. The trial will also evaluate the importance of postoperative cognitive decline on measures of cognitive function and quality of life 6 months after surgery, and whether perioperative 17 beta-estradiol treatment improves these outcomes.