MR angiographic evaluation of carotid and intracranial arteries in Japanese patients scheduled for coronary artery bypass grafting.

BACKGROUND AND PURPOSE

Stroke is a serious complication of coronary artery bypass grafting (CABG). Preoperative evaluation of the cerebral arteries to identify patients at increased risk of stroke after CABG is important. In a prospective study, we evaluated cerebral artery occlusive lesions with MR angiography in Japanese patients scheduled to undergo CABG to determine the prevalence of occlusive diseases in the extracranial carotid and intracranial arteries in this population and to identify preoperative risk factors for these patients.

METHODS

The subjects were 151 consecutive patients (115 men and 36 women ranging in age from 41 to 82 years) who were scheduled for CABG under nonemergency conditions between October 1995 and February 1998. Carotid and intracranial arteries were examined for occlusive lesions with MR angiography. Patient demographics and risk factors including age, sex, hypertension, diabetes mellitus, hyperlipidemia, smoking habit, history of stroke, peripheral vascular disease and preoperative thromboembolic infarcts revealed by MR imaging were recorded and analyzed.

RESULTS

Cervical carotid artery stenoses of more than 50% narrowing were detected in 16.6% of the subjects, and intracranial artery stenoses of more than 50% narrowing were detected in 21.2% of the subjects. Multiple logistic regression analyses identified peripheral vascular disease and lacunar infarcts in the basal ganglia as significant and independent predictors of cervical carotid arterial stenoses. No significant predictor for intracranial arterial stenoses was identified.

CONCLUSIONS

The prevalence of extracranial carotid and intracranial artery stenosis in Japanese patients scheduled for CABG is considerably high. MR angiography is of value of identifying these patients. Preoperative evaluation of cranial arteries is recommended, particularly in patients with peripheral vascular disease and infarcts in the basal ganglia.