Transcranial and carotid Doppler study in coronary artery bypass graft patients

OBJECTIVE: Atherosclerosis is a pathogenesis which is common in both coronary and intracranial arterial diseases. Therefore, we designed a group of coronary artery bypass graft (CABG) surgery patients for transcranial Doppler (TCD) to assess intracranial artery diseases and carotid duplex studies to assess carotid artery diseases.

METHODS: In a prospective randomized study, 129 elective CABG patients with proven coronary artery disease by angiography, were examined by TCD and 45 patients by carotid duplex preoperatively. Neurologic examination was carried out pre- and post- operatively. This study was carried out from April 2001 to August 2002 at Imam Hospital of Tabriz Medical Science University, Iran.

RESULTS: Out of the 129 CABG patients, there were 105 males and 24 females, with an average age of 57+\-9.9 years. Risk factors were as follows: smoking in 44.8%, hypertension in 38%, hypercholesterolemia in 29%, and diabetes mellitus in 18.6%. The TCD findings of 30 patients (23.2%, 11 female and 19 male) revealed the following abnormalities: stenosis of basilar artery in 7 patients (5.4%), carotid siphon in 3 (2.3%), intracranial internal carotid in 5 (3.9%), middle cerebral artery in 3 (2.3%) and vertebral artery in one patient (0.8%). Multiple vessel abnormality was detected in 11 patients (8.5%). There was a significant correlation between severity of coronary artery disease in angiography and abnormality in TCD (p=0.008). The TCD abnormality was detected more in females (p=0.008) or hypertensive patients (p=0.004). In the carotid duplex study of the randomized 45 patients, 23 (51.1%) had abnormal results as follows: stenosis <50% in 17 (38%) cases, stenosis between 50-70% in 5 (11%), and hemodynamically significant stenosis (>70%) only in one (2%) patient. There was also significant correlation between severity of coronary involvement and carotid involvement (p<0.01). No stroke occurred in the first postoperative week following CABG surgery.

CONCLUSION: Stenosis of intracranial and carotid arteries was more common in CABG patients with more than 2-coronary vessel involvement or hypertensive or female patients. We recommend TCD and carotid duplex studies in these patients for prevention of probable cerebrovascular accidents.