Coronary artery bypass surgery in patients with chronic brain hypoperfusion

Cerebrovascular disease (CVD) is a risk factor of stroke and cerebral hypoperfusion is one of the underlying mechanisms. We hypothesized that coronary artery bypass grafting (CABG) can be performed at an acceptable risk for such patients without concomitant surgery for CVD.

Carotid echo was carried out for 538 consecutive patients undergoing isolated CABG between 2005 and 2016. Magnetic resonance image/angiography (MRI/A) for neck and brain was performed for 288 patients (stenoses ≥50% in echo were basically included). Patients with multiple severe stenoses (≥70%) and/or occlusion in carotid and/or vertebral systems associated with contra-lateral carotid and/or Willis circle lesions (reduced collateral flow) on MRI/A (N.=43) were investigated. Whenever possible, single photon emission computed tomography (SPECT, N.=20) with or without acetazolamide challenge was performed. Off-pump CABG was used in all patients. Systolic arterial pressure was maintained ≥100 mmHg or ≥90 mmHg with intra-aortic counter-pulsation. Patients were followed up for one year and MRI was performed.

Hypoperfusion and reduced cerebrovascular reserve were observed in 90.0% and 88.9% respectively in patients underwent SPECT. There was one postoperative stroke and no mortality. MRI (N.=32) revealed no new stroke, however, five other patients experienced strokes during follow-up period. In patients without the CVD, there was one stroke in the study period, which was seen postoperatively.

CABG can be performed at an acceptable risk in patients with brain hypoperfusion. However, these patients suffered high stroke incidence during the follow-up. It is therefore, important to identify those patients preoperatively to plan and implement an appropriate treatment regime.