Influence of patient-related and surgery-related risk factors on cognitive performance, emotional state, and convalescence after cardiac surgery

Background: Cardiac surgery may account for complications such as cognitive impairment, depression, and delay of convalescence. This study investigated the influence of different risk factors on cognitive performance, emotional state, and convalescence. Methods: We included 83 patients undergoing cardiac surgery who had no indication of postoperative delirium. Psychometric testing was performed 1 day before and 7 days after surgery. Neuron-specific enolase (NSE) levels were measured 1 day before and 36 h after surgery. Results: Depression score increased after surgery, but patients showed no clinically significant depression. Postoperative cognitive performance correlated with postoperative depression level and preoperative cognitive performance. Forty-three percent of patients showed postoperative decline. Older patients exhibited a higher postoperative increase in NSE concentrations. Patients undergoing coronary artery bypass grafts or combined procedures exhibited more medical risk factors than those undergoing valve surgery alone. The number of bypass grafts was associated with time of hospitalization, and the number of patient-related risk factors correlated with stay in intensive care unit. Conclusions: For elderly patients undergoing cardiac surgery, older age, total preexisting medical risk factors, and surgery duration seem to be the most important factors influencing cognitive outcome and convalescence. Results show that, also for patients without postoperative delirium, medical risk factors and intraoperative parameters can result in delay of convalescence. (C) 2007 Elsevier Inc. All rights reserved.