Carotid artery stenosis of ≥50% was not significantly predictive of stroke in patients with atrial fibrillation treated with aspirin or warfarin (RR 1.3; 95% CI 0.5-3.6; P=0.55).
Observational (n=676)
Does the presence of carotid stenosis ≥50% predict subsequent stroke in patients with atrial fibrillation receiving aspirin or warfarin?
Routine carotid ultrasonography is not warranted in asymptomatic patients with atrial fibrillation, as carotid stenosis does not independently predict stroke risk in those receiving antithrombotic therapy.
Relative Risk: 1.3 (95% CI 0.5–3.6)
p-value: p=.55
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 ultrasonography was done in 676 patients with AF enrolled in the Stroke Prevention in Atrial Fibrillation Study to detect cervical carotid stenosis of 50% or more of the luminal diameter. The presence of carotid stenosis 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 systolic hypertension (relative risk, 2.4; P = .002), diabetes (relative risk, 1.8; P = .04), and tobacco use (relative risk, 1.8; P = .02). Carotid stenosis did not add significantly to prediction of stroke when analyzed 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). CONCLUSIONS: Carotid artery stenosis of 50% or more occurs in about 12% of elderly patients with AF, reflecting the substantial prevalence of hypertension and diabetes in these patients. Carotid stenosis was not usefully predictive of stroke in patients with AF who were given aspirin or warfarin. Routine ultrasonography to detect carotid stenosis does not appear warranted in patients with AF without previous symptoms of brain ischemia.
Merrill C. Kanter (1994) conducted an observational in Atrial fibrillation (n=676). Carotid artery stenosis ≥50% vs. No carotid artery stenosis ≥50% was evaluated on Stroke (RR 1.3, 95% CI 0.5-3.6, p=.55). Carotid artery stenosis of ≥50% was not significantly predictive of stroke in patients with atrial fibrillation treated with aspirin or warfarin (RR 1.3; 95% CI 0.5-3.6; P=0.55).