CAROTID STENOSIS IN PATIENTS WITH ATRIAL-FIBRILLATION - PREVALENCE, RISK-FACTORS, AND RELATIONSHIP TO STROKE IN THE STROKE PREVENTION IN ATRIAL-FIBRILLATION STUDY

Background: Several mechanisms contribute to the increased stroke rate of patients with atrial fibrillation (AF). We assessed the frequency of carotid artery stenosis in patients with AF and its relationship to stroke during aspirin or warfarin therapy. Methods: Carotid ultrasono graphy was done in 676 patients with AF enrolled in the Stroke Prevent ion in Atrial Fibrillation Study to detect cervical carotid stenosis o f 50% or more of the luminal diameter. The presence of carotid stenosi s was correlated with patient features and subsequent stroke during a mean of 2.6 years of follow-up. Results: In patients with AF who were older than 70 years, the frequency of carotid stenosis was 12% in men and 11% in women. Carotid stenosis was independently associated with s ystolic hypertension (relative risk, 2.4; P=.002), diabetes (relative risk, 1.8; P=.04), and tobacco use (relative risk, 1.8; P=.02). Caroti d stenosis did not add significantly to prediction of stroke when anal yzed with other clinical risk factors for stroke in patients with AF ( relative risk, 1.3; 95% confidence interval, 0.5 to 3.6; P=.55). Concl usions: Carotid artery stenosis of 50% or more occurs in about 12% of elderly patients with AF, reflecting the substantial prevalence of hyp ertension and diabetes in these patients. Carotid stenosis was not use fully predictive of stroke in patients with AF who were given aspirin or warfarin. Routine ultrasonography to detect carotid stenosis does n ot appear warranted in patients with AF without previous symptoms of b rain ischemia.