Trend in Mortality after Stroke with Atrial Fibrillation

Abstract 

Purpose

To evaluate trend in mortality in stroke associated with atrial fibrillation, we examined mortality trend after stroke with atrial fibrillation by calendar year period (1980-1984, 1985-1989, 1990-1994, 1995-1999, and 2000-2002). We estimated trends separately for each sex in unadjusted analyses. We also adjusted for age, comorbid conditions, and general trend in mortality in the background population.

Methods

We identified all individuals, aged 40-89 years, with an incident diagnosis of stroke of any nature (ischemic or hemorrhagic) and no history of heart valve disease and a previous or concomitant diagnosis of atrial fibrillation or flutter in the Danish National Registry of Patients. Subjects were followed in the Danish Civil Registration System for emigration and vital status. We used multivariate Cox proportional hazards regression analysis to estimate trend in mortality.

Results

Incident stroke with a previous or concomitant diagnosis of nonvalvular atrial fibrillation or flutter was diagnosed in 24,470 subjects (11,554 men and 12,916 women). During 34,405 years of observation, 9237 men died, and during 35,381 years of observation, 10,827 women died. The hazard ratio for mortality after stroke in the last 3-year period compared with the first 5-year period was .65 (95% confidence interval [CI], .61-.71) in men and .69 (95% CI, .64-.74) in women.

Conclusions

We observed a substantially better survival in men and women after stroke associated with atrial fibrillation or flutter in Denmark during the years 1980 to 2002. However, we could not control for changes in admission practice, diagnostic performance, or treatment.

Keywords: Arrhythmia, Cohort study, Epidemiology, Mortality