Risk factors for early or delayed stroke after cardiac surgery

Background-Stroke after cardiac surgery is a devastating complication that leads to excess mortality and health resource utilization. The purpose of t his study was to identify risk factors for perioperative stroke, including strokes detected early after cardiac surgery or postoperatively. Methods and Results-Data were obtained from 2972 patients undergoing corona ry artery bypass graft and/or valve surgery. Patients greater than or equal to 65 years old and those with a history of symptomatic neurological disea se underwent preoperative carotid artery ultrasound scanning. Intraoperativ e epiaortic ultrasound to assess for ascending aorta atherosclerosis was pe rformed in all patients. New strokes were considered as a single end point and were categorized with respect to whether they were detected immediately after surgery (early stroke) or after an initial, uneventful neurological recovery from surgery (delayed stroke). Strokes occurred in 48 patients (1. 6%); 31 (65%) were delayed strokes. By multivariate analysis, prior neurolo gical event, aortic atherosclerosis, and duration of cardiopulmonary bypass were independently associated with early stroke, whereas predictors of del ayed stroke were prior neurological event, diabetes, aortic atherosclerosis , and the combined end points of low cardiac output and atrial fibrillation . Female sex was associated with a 6.9-fold increased risk of early stroke and a 1.7-fold increased risk of delayed stroke, In-hospital mortality of p atients with early (41%) and delayed (13%) strokes was higher than that of other patients (3%, P = 0.0001). Conclusions-Most strokes after cardiac surgery occurred after initial uneve ntful recovery from surgery. Women were at higher risk to suffer early and delayed perioperative strokes. Atrial fibrillation had no impact on postope rative stroke rate unless it was accompanied by low cardiac output syndrome .