Incident stroke after discharge from the hospital with a diagnosis of atrial fibrillation

PURPOSE: Atrial fibrillation is an important risk factor for stroke. We ana lyzed stroke risk over time in patients discharged from the hospital with a diagnosis of incident atrial fibrillation as compared with the risk of str oke in the Danish population. SUBJECTS AND METHODS: In a random sample of half of the Danish population, we identified 13,625 men and 13,577 women, aged 50 to 89 years, with a hosp ital diagnosis of atrial fibrillation and no prior diagnosis of stroke duri ng 1980 to 1993. Data on other medical conditions were also available from 1977 to 1993, but medication data were not available. Patients were followe d from the diagnosis of atrial fibrillation until the first diagnosis of st roke (nonfatal or fatal cerebral ischemic infarct and cerebral hemorrhage), death, or the end of 1993. The risk of stroke in these patients was compar ed with the risk in the Danish population using Poisson regression modeling to estimate relative risks (RR) and 95% confidence intervals (CI). RESULTS: For men with atrial fibrillation, the stroke rates increased by ag e, from 13 per 1,000 person-years in those ages 50 to 59 years, to 22 per 1 ,000 person-years in those ages 60 to 69 years, to 42 per 1,000 person-year s In those ages 70 to 79 years, to 51 per 1,000 person-years in those ages 80 to 89 years. Age-specific stroke rates were similar id women with atrial fibrillation. Patients with a hospital diagnosis of atrial fibrillation ha d an increased risk of stroke (RR = 2.4; 95% CI, 2.3 to 2.5 in men and RR = 3.0; 95% CI, 2.9 to 3.2 in women) compared with the Danish population. Str oke risk was greatest during the first year after discharge and decreased t hereafter. Hypertension, diabetes, and peripheral atherosclerosis were also associated with an increased risk of stroke among patients with atrial fib rillation. Ischemic heart disease and heart failure were risk factors in me n only. There was no reduction in the risk of stroke from 1980 to 1993. CONCLUSIONS: Men and women with atrial fibrillation are at a substantially increased risk of stroke, particularly in the first year after the diagnosi s. Am J Med.2000;108:36-40. (C)2000 by Excerpta Medica, Inc.