Time trends of ischemic stroke incidence and mortality in patients diagnosed with first atrial fibrillation in 1980 to 2000: report of a community-based study

Abstract

Background and purpose: With the changes in management of atrial fibrillation (AF) over time, it is possible that the time trends of post-AF stroke incidence and mortality have changed. We sought to determine whether the incidence and survival of ischemic stroke after AF diagnosis have improved.

Methods: We identified the Olmsted County, Minn, residents who developed first AF from 1980 to 2000 and followed them in medical records to 2004. The outcomes were first ischemic stroke and death.

Results: Of the 4117 subjects diagnosed with first AF and without previous stroke, 446 (11%) sustained a first ischemic stroke during a mean follow-up time of 5.5+/-5.0 years. The age- and sex-adjusted incidence of stroke decreased, on average, by 3.4% per year (P=0.0001), concurrent with an increase in warfarin and aspirin use (both P<0.0001) and reduction of systolic blood pressure (P<0.001). The age-adjusted ischemic stroke incidence was higher in women (P=0.039), but not after adjusting for systolic blood pressure (P=0.41). Compared with the general Minnesota white population, the relative mortality hazard ratio was 1.88 for men and 1.84 for women without stroke and 3.03 for men and 3.80 for women (P<0.05) with stroke. The relative mortality hazard did not vary by age or calendar year of AF diagnosis.

Conclusions: Post-AF ischemic stroke incidence decreased significantly from 1980 to 2000, during which time a substantial increase in the use of antithrombotic therapy and reduction of systolic blood pressure was evident. The relative mortality risk of stroke, however, had not improved over time.