Ann Thorac Surg 1996;62:1723
© 1996 The Society of Thoracic Surgeons
Invited Commentary
Invited Commentary
Nicholas T. Kouchoukos, MD
Missouri Baptist Medical Center, Suite 266C, 3009 North Ballas Rd, St. Louis, MO 63131
See also page 1714.
From this critical analysis of patients undergoing coronary artery bypass grafting and preoperative noninvasive carotid artery screening, D'Agostino and associates have identified risk factors that predict the presence of significant (defined as greater than 50%) carotid artery stenosis. With few exceptions, they are identical to those reported in other studies of large populations of patients that used preoperative noninvasive carotid artery screening to detect carotid artery disease. The prevalence of carotid artery disease in this population of patients is also similar to that reported from other studies. The study adds strong support to the concept that carotid artery disease is an important predictor of stroke after coronary artery bypass grafting.
D'Agostino and associates identified other risk factors predictive of postoperative stroke, the most important being atherosclerosis of the ascending aorta and macroemboli of cardiac origin. Atherosclerosis of the ascending aorta was associated with the largest number of postoperative strokes. Yet, by D'Agostino and associates' own admission, the incidence of ascending aortic atherosclerosis was underestimated, because only a percentage of the patients underwent epiaortic ultrasonographic scanning, which is currently the most accurate method for identifying ascending aortic atherosclerosis. Thus, the importance of this variable as a cause of stroke was underestimated.
Which patients should be studied preoperatively for carotid artery disease, and how should asymptomatic patients with hemodynamically important carotid artery stenoses be managed during a cardiac operation? These are questions without definitive answers at the present time. What is clear, however, is that any study evaluating the importance of carotid artery disease as a predictor of postoperative stroke must also evaluate the prevalence of atherosclerotic disease in the ascending aorta and arch. Techniques are now available to assess the carotid arteries (preoperative duplex scanning) and the ascending aorta (intraoperative epiaortic ultrasonographic imaging), and to identify intracardiac thrombus (preoperative or intraoperative transesophageal echocardiography). Future studies should focus on the prospective identification of all of these risk factors to more accurately assess their importance as causes of postoperative stroke and, hopefully, to formulate strategies that will reduce the incidence of this important complication.
Related Article
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Screening Carotid Ultrasonography and Risk Factors for Stroke in Coronary Artery Surgery Patients
- Richard S. D'Agostino, Lars G. Svensson, Deborah J. Neumann, Husam H. Balkhy, Warren A. Williamson, and David M. Shahian
Ann. Thorac. Surg. 1996 62: 1714-1723.
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