BACKGROUND: The purpose of this study was to investigate whether the incidenceof stroke after off-pump AC bypass was lower than that after on-pump AC bypass. MATERIAL/METHODS: A prospectivestudy was performed with consecutive patients who underwent isolated AC bypass in the Shin-Tokyo HospitalGroup between July 1, 1996 and December 31, 2001 AC bypass was defined as coronary artery bypass requiringproximal anastomoses onto the ascending aorta. The patients were divided into two groups, depending onthe use of cardiopulmonary bypass: on-pump and off-pump groups. Perioperative data were prospectivelycollected and the risk factors for postoperative stroke were investigated. RESULTS: Preoperative comorbiditieswere more frequent in the off-pump group. The number of distal anastomoses was not significantly differentbut the number of proximal anastomoses was significantly greater in the on-pump group than in the off-pumpgroup. The incidence of postoperative stroke was 0.3% in the off-pump group and 2.0% in the on-pump group.Significant risk factors influencing the occurrence of postoperative stroke included: use of cardiopulmonarybypass, age over 75, peripheral vascular disease, saphenous vein use, and postoperative atrial fibrillation.Multivariate analysis demonstrated that the use of cardiopulmonary bypass, age over 75, and peripheralvascular disease were isolated predictors of postoperative stroke. CONCLUSIONS: The incidence of postoperativestroke was lower in the off-pump group than in the on-pump group, even though the side clamp was appliedto the ascending aorta for aortocoronary bypass. The use of side clamping for off-pump AC bypass doesnot increase the risk of postoperative stroke.

Keywords: Cardiopulmonary Bypass, Catheterization, Cerebrovascular Accident, Comorbidity, Comparative Study, Coronary Artery Bypass, Diabetes Mellitus, Heart-Lung Machine, hyperlipidemia, Hypertension, Incidence, Obesity, Peripheral Vascular Diseases, Prospective Studies, Risk, Risk Factors, Smoking, Stress, Mechanical, Atrial Fibrillation