Cerebral lesions in patients undergoing coronary artery bypass grafting in relation to asymptomatic carotid and vertebral artery stenosis.

Objectives: Carotid artery stenosis (CAS) and vertebral artery stenosis (VAS) are associated with cerebral infarction after coronary artery bypass graft surgery (CABG). It remains unclear whether this association is causal. We investigated the associations between neurologically asymptomatic CAS and VAS and the occurrence of subclinical cerebral lesions after CABG verified by magnetic resonance imaging.

Methods: CABG patients were included and CAS and VAS were identified by magnetic resonance angiography. Cerebral magnetic resonance imaging was performed to identify new post-operative subclinical cerebral lesions. The associations between CAS/VAS post-operative cerebral lesions were investigated.

Results: Forty-six patients were included in the study. 13% had significant CAS and 11% had significant VAS. Thirty-five percent had new cerebral infarction postoperatively. We found a significant association between the presence of cerebral vessel stenosis and acute cerebral infarction (67% vs. 27%, p = 0.047). However none of the patients with stenosis had isolated cerebral lesions in the ipsilateral vascular territory.

Conclusion: Asymptomatic CAS and VAS is common in CABG patients and is associated with an increased risk of postoperative cerebral infarction. Our study suggests that asymptomatic CAS and VAS primarily are risk markers rather than causal factors for cerebral infarction after CABG.