Prognostic Importance of Leukoaraiosis in Patients With Symptomatic Internal Carotid Artery Stenosis

Background and Purpose— Leukoaraiosis (LA) is a frequent finding on brain CT scans. This study examined patients with LA and symptomatic internal carotid artery disease. Methods— Patients in the North American Symptomatic Carotid Endarterectomy Trial were evaluated for the extent of LA. Long-term prognosis and perioperative risk associated with carotid endarterectomy were assessed. Results— Among 2618 patients, 493 had LA: 354 restricted and 139 widespread. Patients with LA were older, had a history of hypertension, had more hemispheric ischemic events (particularly stroke), and had small, deep brain infarcts. The 3-year risks of stroke for medically treated patients were 20.2% (no LA), 27.3% (restricted LA), and 37.2% (widespread LA) (P =0.01). For surgically treated patients, the risks were 14.2%, 25.4%, and 33.6%, respectively (P <0.001). With widespread LA, occurrence of disabling strokes doubled in medical patients and tripled in surgical patients. The 30-day perioperative risks of any stroke or death for surgical patients with 50% to 99% internal carotid artery stenosis were 5.3% (no LA), 10.6% (restricted LA), and 13.9% (widespread LA). Despite higher perioperative risk, endarterectomy reduced the absolute 3-year risk of stroke ipsilateral to the symptomatic 50% to 99% stenosed artery by 11.6% (P =0.46) for patients with widespread LA, 7.6% (P =0.39) with those with restricted LA, and 10.9% (P <0.001) for those with no LA. Conclusions— In patients with a transient ischemic attack or nondisabling stroke associated with internal carotid artery disease, presence of LA was associated with an increased risk of any stroke and of disabling or fatal stroke. Patients with widespread LA had the worst prognosis. Despite the higher perioperative risk, endarterectomy reduced the risk of stroke.