Risk factors of stroke and delirium after off-pump coronary artery bypass surgery.

Off-pump coronary artery bypass surgery (CABG) has not abolished the risk of postoperative stroke and delirium seen for on-pump CABG. Advanced arteriosclerotic changes are common in both on-pump and off-pump CABG. We sought to analyze if advanced arteriosclerotic changes are risk factors of stroke or transient ischemic attack (TIA), and delirium after off-pump CABG. Patients undergoing off-pump CABG between 2001 and 2005 were reviewed using medical records (n=685). Potential risk factors of postoperative stroke and delirium were identified from previous studies. Further, variables retrieved from carotid artery duplex scanning as indices of advanced arteriosclerosis, were examined. The incidences of postoperative stroke/TIA and delirium after off-pump CABG were 2.6% (n=18) and 16.4% (n=112), respectively. Carotid artery stenosis >50% was a significant risk factor of stroke or TIA (P=0.02) as well as delirium (P=0.04) after off-pump CABG. A history of atrial fibrillation (AF) (P=0.037) or diabetes mellitus (P=0.041) was a risk factors of postoperative stroke or TIA. In contrast, age over 75 years (P=0.006), creatinine >1.3 mg/dl (99 μmol/l) (P=0.011), a history of hypertension (P=0.001), past history of AF (P=0.024), and smoking (P=0.048) were significant risk factors of postoperative delirium.