SEVERITY OF ATHEROSCLEROSIS IN BRAIN, CAROTID ARTERY AND ASCENDING AORTA

Abstract

Introduction: Coronary heart disease is a known risk factor for systemic atherosclerosis. Cerebral ischemic disorders and carotid stenosis tend to impair the cerebral autoreguration mechanism, which may cause hypoperfusion during cardiopulmonary bypass (CPB) [1]. Advanced atheromatous disease of the ascending aorta is a major risk factor for perioperative stroke [2]. We studied whether varying degrees of the total atherosclerotic score of brain, carotid artey and ascending aorta predicted postoperative neurological dysfunction in patients undergoing coronary artery bypass grafting (CABG). Methods: 138 patients underwent preoperative magnetic imaging and angiography (MRI, MRA) to detect small cerebral infarctions (grade: 0-4) and carotid artery stenosis (grade: 0-3). The degree of atherosclerosis of the ascending aorta (grade: 1-3) was identified by intraoperative epiaortic ultrasonography. Patients underwent the Hasegawa-dementia scale (full score 30) [3] as a neuropsychological (NP) test in the preoperative period (baseline), and on the first and seventh days postoperatively. The presence of stroke was confirmed by a staff neurologist using preoperative MRI and postoperative MRI and CT. Patients were divided into 3 groups according to total atherosclerotic score: GroupL, low score <or=to 4 (n=100); GroupI, intermediate score = 5 (n=25) and GroupH, high score >or=to 6 (n=13). The incidence of NP dysfunction and stroke after CPB were compared among the 3 groups. Data were analyzed by Chi squared test and ANOVA. P<0.05 was required for significance. Results: Multiple small infarctions, carotid stenosis and severe aortic atherosclerosis were found to be predictive risk factors for postoperative NP dysfunction. The incidence of NP dysfunction after CPB was significantly higher in GroupH than in the other two groups in postoperativedays 1 and 7 (p<0.001, P<0.001, Table 1). No stroke occurred in 113 patients with aortic grade 1 or 2, while the intraoperative stroke rate was 8.0% (2/25) for grade 3 (p=0.003).Table 1Conclusions: The incidence of NP dysfunction after CPB was demonstrated to increase in patients who had a higher total atherosclerotic score. Perioperative evaluation of atherosclerotic disease in the brain, carotid artery and aorta is useful for applying preventive measure of postoperative neurological dysfunction after CABG.