Stroke Risk After Coronary Artery Bypass Graft Surgery and Extent of Cerebral Artery Atherosclerosis
What is the relationship between cerebral atherosclerosis and stroke after coronary artery bypass grafting (CABG)?
The authors performed preoperative magnetic resonance angiography (MRA) on 1,367 consecutive patients undergoing CABG at one large-volume Korean center. Disease severity was evaluated by atherosclerosis score, which was determined by the number and severity of stenosis of cerebral arteries. Strokes occurring within 14 days were considered post-CABG strokes and were classified as atherosclerotic (strokes attributable to predefined atherosclerosis) or other (strokes caused by other mechanisms). Patients with severe asymptomatic (>80%) stenosis or symptomatic stenosis of the extracranial carotid artery underwent stenting if the surgery could be delayed 4 weeks.
Postoperative stroke occurred in 33 patients. The independent predictors of stroke were preoperative atrial fibrillation (odds ratio [OR], 3.68), hypercholesterolemia, and the atherosclerosis score (OR, 1.35; 95% confidence interval, 1.16-1.56, p < 0.001). An atherosclerosis score of ≥2 had a sensitivity of 81% and specificity of 58% to predict postoperative stroke. Isolated extracranial carotid artery disease was not associated with stroke, whereas intracranial disease or a combination of extra- and intracranial disease was associated with a high risk of stroke. None of the patients who underwent preoperative carotid stenting had a stroke.
The authors concluded that cerebral atherosclerosis is strongly associated with occurrence of post-CABG stroke.
This is an important study that elegantly defines the association between cerebral atherosclerosis and stroke in patients undergoing CABG. It is not clear, however, if these findings are unique to Korean patients or if they can be replicated in a larger more diverse population. Preoperative determination of cerebral atherosclerosis may be of value in determining stroke risk for patients undergoing CABG, and in select patients, may help guide choice of revascularization strategy until future studies define the optimal strategy for reducing stroke risk in these patients.
Clinical Topics: Cardiac Surgery, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Vascular Medicine, Homozygous Familial Hypercholesterolemia, Interventions and Imaging, Interventions and Vascular Medicine, Angiography, Magnetic Resonance Imaging
Keywords: Stroke, Atherosclerosis, Carotid Artery Diseases, Hypercholesterolemia, Coronary Artery Bypass, Magnetic Resonance Angiography, Intracranial Arteriosclerosis
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