Risk of cerebrovascular accident after a first diagnosis of atrial fibrillation.

Background: Atrial fibrillation is the most common cardiac arrhythmia and a major risk factor for cerebrovascular accident, including ischemic stroke and transient ischemic attack.

Hypothesis: Ischemic cerebrovascular accident is associated with increasing age and cardiovascular and cerebrovascular disease in primary care patients with atrial fibrillation.

Methods: Using the U.K. General Practice Research Database, we identified patients with chronic atrial fibrillation who were alive 1 month after initial diagnosis (n = 906). Potential cases of cerebrovascular accident were identified and confirmed by the primary care physician. The incidence of cerebrovascular accident was calculated. A nested case-control analysis was performed to identify factors associated with cerebrovascular accident among patients with chronic atrial fibrillation.

Results: During a mean follow-up period of 1.8 years (range: 0-3.9 years), 60 patients with atrial fibrillation were diagnosed with a new cerebrovascular accident (22 cases with transient ischemic attack and 38 with ischemic stroke). The incidence of new cerebrovascular accident was 3.6 per 100 patient-years (95% confidence interval [CI]: 2.8-4.6). Increased age (odds ratios [OR] compared with age 40-69 years: 3.5 [95% CI: 1.2-10.5] for age 70-79 years and 4.9 [95% CI: 1.6-15.0] for age > or = 80 years), prior cerebrovascular event (OR: 3.4; 95% CI: 1.9-6.1) and diabetes (OR: 2.2; 95% CI: 1.0-4.9) were identified as risk factors for a new cerebrovascular accident.

Conclusions: Among patients with atrial fibrillation, risk factors for a new ischemic cerebrovascular accident include previous ischemic stroke or transient ischemic attack, comorbid diabetes, and increasing age.