Does preoperative screening with computed tomography of the chest decrease risk of stroke in patients undergoing coronary artery bypass grafting.

Background: Stroke is one of the most feared complications post coronary artery bypass with aortic calcifications being the commonest source of embolic stroke. The aim of our study was to determine the clinical impact and usefulness of routine use of plain chest computerised tomography to screen for aortic calcification on incidence of postoperative stroke in coronary artery bypass grafting (CABG) patients.

Methods: This is a retrospective case-control study that included four hundred and five patients who underwent primary isolated CABG and had preoperative plain chest computerised tomography as a screening for aortic calcification. Aortic calcification was classified according to the area involved (ascending, arch, arch vessels and descending aorta) and the pattern of calcification. Patients were divided into two groups according to the incidence of postoperative stroke and the aortic calcification distribution was compared between the two groups. Stroke predictors were studies using univariate and multivariate regression analysis.

Results: Fourteen patients (3.5%) developed postoperative stroke. There was no difference in preoperative and operative characteristics between patients who developed postoperative stroke and those who did not, except for the history of preoperative stroke or transient ischemic attack (TIA) that was higher in the group who developed postoperative stroke (50.00% 6.19%, P<0.001). Patients who developed postoperative stroke had higher percentage of aortic root calcification (78.57% 64.18%), ascending aortic calcification (28.57% 19.07%) and descending aortic calcification (85.71% 73.71%) but none of them reached statistical significance. History of preoperative stroke or TIA was the only significant predictor of postoperative stroke using both univariate and multivariate regression models.

Conclusions: Our study showed the importance of preoperative computed tomography (CT) scan of the chest as a screening tool as it detected a high prevalence of aortic calcification in our patients. However, its impact on prevention of postoperative stroke needs to be investigated further in future prospective studies.