Anticoagulation for atrial fibrillation and stroke prevention.
Nonvalvular atrial fibrillation (NVAF) has a prevalence of about 1% in the 60- to 70-year age group, increasing to above 4% in persons older than 80 years. The yearly stroke incidence in NVAF patients is 3-8%, which is 5-7 times higher than that in age-matched persons in sinus rhythm. In five independent studies of stroke prevention in NVAF patients, anticoagulation therapy resulted in a risk reduction of stroke of about 65%. The risk of intracerebral hemorrhage was 0.3% per year during warfarin therapy compared with 0.1% in the placebo group. In one study aspirin reduced the risk of thromboembolic events by 42% while another study found a nonsignificant effect of aspirin. The following variables were identified as risk factors for stroke in the individual studies: prior myocardial infarction, increasing age, mitral annular calcification, history of hypertension, congestive heart failure and previous arterial thromboembolism. A pooled analysis of risk factors in the placebo-treated patients of the five studies is ongoing.
Boysen
G
G
Department of Neurology, Hvidovre Hospital, University of Copenhagen, Denmark.
D000367:Age Factors; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D002561:Cerebrovascular Disorders / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011322:Primary Prevention; D012307:Risk Factors
D000925:Anticoagulants; D001241:Aspirin